Environmental Impact Assessment of (2 x 363.3 MW) +15% Gas …€¦ · Harnessing solar power within the premises of the plant particularly at available roof tops and other available

The business of sustainability

Environmental Impact Assessment of (2 x 363.3 MW) +15% Gas Based Combined Cycle Power Plant (Expansion): Palatana, Gomti District, Tripura

February 2019

FINAL REPORT

ONGC Tripura Power Company Ltd (OTPC)

Environmental Impact Assessment of (2 x 363.3 MW) +15% Gas BasedCombined Cycle Power Plant (Expansion): Palatana, Gomti District, Tripura Environmental Consultant: ERM India Private Limites, Gurgaon; NABET Accredited as per certificate No.: NABET/EIA/1619/ RA 0055; Valid till 31 October 2019 February 2019 Reference # 0397129

Version/ Revision

Description Coordinated by

Reviewed by Approved by

01 Final EIA Report

Salil Das

Debanjan Bandyapadhyay; Partner

Neena Singh : Managing Director

This report has been prepared by ERM India Private Limited a member of Environmental Resources Management Group of companies, with all reasonable skill, care and diligence within the terms of the Contract with the client, incorporating our General Terms and Conditions of Business and taking account of the resources devoted to it by agreement with the client. We disclaim any responsibility to the client and others in respect of any matters outside the scope of the above. This report is confidential to the client and we accept no responsibility of whatsoever nature to third parties to whom this report, or any part thereof, is made known. Any such party relies on the report at their own risk.

ERM OTPC, PALATANA EXPANSION PROJECT PROJECT # 0397129 FEBRUARY 2019

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COMPLIANCE OF APPROVED TERMS OF REFERENCE (TOR) FOR THE EIA STUDY The terms of reference (ToR) for conduct of EIA study as approved by EAC of MoEFCC has been provided at Annex A. The ToR requirements and their compliance and reference in the EIA study have been described in Table-1.

Table 1 Requirements & Compliance of Approved Terms of Reference for the EIA

Ref. No.

ToR Points Compliance

i. The proposed project shall be given a unique name in consonance with the name submitted to other Government Departments etc. for its better identification and reference.

The name of the project is “726 MW +15% OTPC Palatana Expansion Project”.

ii. Vision document specifying prospective long term plan of the project shall be formulated and submitted

OTPC Vision Document is attached in Annex-1.1.

iii. Latest compliance report duly certified by the Regional Office of MoEF& CC for the conditions stipulated in the environmental and CRZ clearances of the previous phase(s) for the expansion projects shall be submitted.

The latest compliance report certified by RO of MoEFCC is attached in Annex 2.7

iv. The project proponent needs to identify minimum three potential sites based on environmental, ecological and economic considerations, and choose one appropriate site having minimum impacts on ecology and environment. A detailed comparison of the sites in this regard shall be submitted

The proposed expansion will be undertaken within the existing power plant area. No additional land will be required for the expansion project. The alternative study has been carried out in respect of greenfield site vis-à-vis brownfield site as well as environmental and technological alternatives .(Refer: Chapter 5)

v. Executive summary of the project indicating relevant details along with recent photographs of the proposed site (s) shall be provided. Response to the issues raised during Public Hearing and the written representations (if any), along with a time bound Action Plan and budgetary allocations to address the same, shall be provided in a tabular form, against each action proposed

Executive summary of the EIA report is provided at the beginning of the report. The photographs of the proposed site are provided in Section 2.5. The Public Hearing (PH) was conducted on 04.10.2018 by TSPCB; the PH issues and action plan is provided in Section 7.2.3.

vi. Harnessing solar power within the premises of the plant particularly at available roof tops and other available areas shall be formulated and for expansion projects, status of implementation shall also be submitted

5 Nos. of solar street lights and 35 Nos. of solar garden lights have been installed and installation of more street lights is being taken up. OTPC has also undertaken the Pre-Feasibility study for setting up of solar rooftop PV Power Plants through Solar Energy Corporation of India, Government of India Enterprise (Refer Section 2.8.4).


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vii. The geographical coordinates (WGS 84) of the proposed site (plant boundary), including location of ash pond along with topo sheet (1:50,000 scale) and IRS satellite map of the area, shall be submitted. Elevation of plant site and ash pond with respect to HFL of water body/nallah/River and high tide level from the sea shall be specified, if the site is located in proximity to them

The geographical coordinates of the plant on satellite imagery is provided in Figure 2.2. The site is located in the Survey of India Toposheet No. 79 M/7. The Survey of India Dehradun Office communicated that 1;50,000 scale Topographic Map 79 M/7 is frozen/ not available. The site location has been indicated on topographic map of 1:250,000 scale. The existing plant and proposed expansion unit is gas based thermal power plant; therefore, ash pond is not required. The Gumti River is located 2.0 km from the site. Plant site elevation is about 30 m and elevation level of Gumti River is about 20 m. Contoru map of study area showing elevation of Gumti River and plant site is presented in fig 4.3 of Eco-Hydrological Study report undertaken by NIT Agartala. Report has been presented in Annex C-

viii. Layout plan indicating break-up of plant area, ash pond, green belt, infrastructure, roads etc. shall be provided

The plant layout map is presented in Figure 2.14. The existing facilities, and land use map is presented in Figure 2.5 and Figure 2.7 respectively.

ix. Land requirement for the project shall be optimized and in any case not more than what has been specified by CEA from time to time. Item wise break up of land requirement shall be provided

The land use of the existing plant and proposed expansion unit is provided in Section 2.4 and Figure 2.7.

x. Present land use (including land class/kism) as per the revenue records and State Govt. records of the proposed site shall be furnished. Information on land to be acquired including coal transportation system, laying of pipeline, ROW, transmission lines etc. shall be specifically submitted. Status of land acquisition and litigation, if any, should be provided

The proposed expansion project would not require any additional land. The existing land use of the plant is industrial land; therefore change in land use is not envisaged for proposed expansion project. Refer - Section 2.4.

xi. If the project involves forest land, details of application, including date of application, area applied for, and application registration number, for diversion under FCA and its status should be provided along with copies of relevant documents

OTPC had received the forest clearance for the existing project. No additional land or forest land will be required for proposed expansion project. (Refer Section 2.4)


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xii. The land acquisition and R&R scheme with a time bound Action Plan should be formulated and addressed in the EIA report

OTPC had acquired 3.49 acres of private land for the existing power plant and compensation was given to the owners of the land. OTPC also acquired 25.45 acres of private land for pipeline and residential colony for the existing plant and compensation for the same has also been awarded. The proposed expansion project would not require any additional land; therefore R&R issue is not applicable for this project.

xiii. Satellite imagery and authenticated topo sheet indicating drainage, cropping pattern, water bodies (wetland, river system, stream, nallahs, ponds etc.), location of nearest habitations (villages), creeks, mangroves, rivers, reservoirs etc. in the study area shall be provided.

The environmental setting of the site and surrounding has been mapped from satellite imagery and same has been presented in Section 2.3 and Figure 2.6.

xiv. Location of any National Park, Sanctuary, Elephant/Tiger Reserve (existing as well as proposed), migratory routes / wildlife corridor, if any, within 10 km of the project site shall be specified and marked on the map duly authenticated by the Chief Wildlife Warden of the State or an officer authorized by him.

Trishna Wildlife Sanctuary is located within 10 km of the project site. ESZ around 0.5 km from the Sanctuary boundary has also been proposed by State forest department and MoEFCC. Projetc site does not fall in the ESZ of Trishna Wildlife Sancturay. The ecological sensitivity map of Trishna Wildlife Sanctuary and Sepahijila Wildlife Sanctuay location w.r.t to project site duly authenticated by PCCF, Wildlife, Govt. of Tripura has been obtained (Refer . Annex-3.5 of Annex A.)

xv. Topography of the study area supported by toposheet on 1:50,000 scale of Survey of India, along with a large scale map preferably of 1:25,000 scale and the specific information whether the site requires any filling shall be provided. In that case, details of filling, quantity of required fill material; its source, transportation etc. shall be submitted

The proposed expansion unit would be constructed within the existing plant area. The site is already developed. No filling work will be required. The topography map of the study area is given in Figure 3.2.

xvi. A detailed study on land use pattern in the study area shall be carried out including identification of common property resources (such as grazing and community land, water resources etc.) available and Action Plan for its protection and management shall be formulated. If acquisition of grazing land is involved, it shall be ensured that an equal area of grazing land be acquired and developed and detailed plan submitted

The land use of the study area is provided in Section 3.2.1, Table 3.1 and Figure 3.3. There is no additional land requirement for the expansion project Common property resources like grazing or community land will not be used for the proposed expansion project. However, other common property resources like surface water from Gumti river will be sourced for proposed project- the water resource conservation plan has been provided in Section 9.3.5.


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xvii. A mineralogical map of the proposed site (including soil type) and information (if available) that the site is not located on potentially mineable mineral deposit shall be submitted

Expansion project to be developed in the esiting plant site and additional land is not required for the expansion project .The project study area mineralogical map is presented on Figure 3.2.

xviii. Details of fly ash utilization plan as per the latest fly ash Utilization Notification of GOI along with firm agreements / MoU with contracting parties including other usages etc. shall be submitted. The plan shall also include disposal method / mechanism of bottom ash

The existing and proposed expansion project is a gas based power plant. Therefore, regulatory requirement related to fly ash generation and its disposal will not be applicable for this project.

xix. The water requirement shall be optimized (by adopting measures such as dry fly ash and dry bottom ash disposal system, air cooled condenser, concept of zero discharge) and in any case not more than that stipulated by CEA from time to time, to be submitted along with details of source of water and water balance diagram. Details of water balance calculated shall take into account reuse and re-circulation of effluents

The proposed expansion project will maintain zero discharge for process water. A part of the treated effluent from the existing plant will be discharged into Gumti River after meeting discharge standard. The project water use detail is presented in Section 2.16. The effluent generated from the proposed expansion unit will be treated through ETP and RO. The treated water will be recycled and reused in cooling system and greenbelt plantation. Water balance is presented in Figure 2.16 and Figure 2.17 respectively.

xx. Water body/Nallah (if any) passing across the site should not be disturbed as far as possible. In case any Nallah / drain is proposed to be diverted, it shall be ensured that the diversion does not disturb the natural drainage pattern of the area. Details of proposed diversion shall be furnished duly approved by the concerned Department of the State

There is no water body/ nallah within the project site. The site is already developed; therefore, diversion of any waterbody and nallah would not be required.

xxii. It shall also be ensured that a minimum of 500 m distance of plant boundary is kept from the HFL of river system / streams etc. and the boundary of site should also be located 500 m away from railway track and National Highways

The Gumti River flows approximately 2.0 km from project site. The site is also located at a distance from nearest National Highway (6.5 km areal distance) and Railway Track (3.2 km areal distance).

xxiii. Hydro-geological study of the area shall be carried out through an institute/ organization of repute to assess the impact on ground and surface water regimes. Specific mitigation measures shall be spelt out and time bound Action Plan for its implementation shall be submitted

Hydro-geological study has been conducted through Civil Engineering Department, National Institute of Technology Agartala. The finding of the study is presented in Section 3.2.7. and detailed report at Annex- C.


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xxiv. Detailed Studies on the impacts of the ecology including fisheries of the River/Estuary/Sea due to the proposed withdrawal of water / discharge of treated wastewater into the River/Sea etc shall be carried out and submitted along with the EIA Report. In case of requirement of marine impact assessment study, the location of intake and outfall shall be clearly specified along with depth of water drawl and discharge into open sea

Water for the proposed expansion project will be sourced from Gumti river. However, no waste water will be discharged into the river from the expansion project. The detailed aquatic ecological study has been conducted through Centre for Environment and Development, Kolkata. The summary of aquatic baseline is presented in Section 3.3.5. and impact on aquatic ecology is discussed in Section 4.3.13. Marine intake and outfall is not applicable for this project.

xxv. Source of water and its sustainability even in lean season shall be provided along with details of ecological impacts arising out of withdrawal of water and taking into account inter-state shares (if any). Information on other competing sources downstream of the proposed project and commitment regarding availability of requisite quantity of water from the Competent Authority shall be provided along with letter / document stating firm allocation of water.

Source of water and its sustainability even in lean season has been studied through NIT, Agartala. Impact on downstream users has been discussed in Section 4.3.8 and impact on aquatic ecology has been discussed in Section 4.3.13. OTPC has obtained water allocation from Public Works Department (Water Resources), Government of Tripura for withdrawal of 125 MLD from Gumti River (Refer Section 2.8.2)

xxvi. Detailed plan for rainwater harvesting and its proposed utilization in the plant shall be furnished.

The summary of rain water harvesting measures is presented in Section 9.3.6 and Rainwater harvesting plan is presented in Annex F.

xxvii. Feasibility of near zero discharge concept shall be critically examined and its details submitted.

Proposed expansion project has planned for zero discharge. (Refer Section 2.8.2)

xxviii. Optimization of Cycles of Concentration (COC) along with other water conservation measures in the project shall be specified.

The existing plant is maintaining COC 5 and proposed expansion project will also maintain the COC 5 (Refer Section 2.8.2.

xxix. Plan for recirculation of ash pond water and its implementation shall be submitted

This is not applicable for this project, as it is gas based power plant.

xxx. Detailed plan for conducting monitoring of water quality regularly with proper maintenance of records shall be formulated. Detail of methodology and identification of monitoring points (between the plant and drainage in the direction of flow of surface / ground water) shall be submitted. It shall be ensured that parameter to be monitored also include heavy metals. A provision for long-term monitoring of ground water table using Piezometer shall be incorporated in EIA, particularly from the study area.

The monitoring network, parameter to be monitored for proposed expansion project has been provided in Section 6.1.1.


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xxxi. Socio-economic study of the study area comprising of 10 km from the plant site shall be carried out through a reputed institute / agency which shall consist of detail assessment of the impact on livelihood of the local communities

OTPC has carried out socio-economic baseline study through SoulAce Consulting Pvt. Ltd, Gurgaon. Agency assessed the impact on livelihood of the local communities and developed the community developmet plan. The report in attached in Annex C. CSR Plan provided under the repeot has been updated by ERM and proposed the CSR budget for the next five years (2019-20 to 2023-23. The summary of the plan is presented in Section 9.3.9 and report is attached in Annex D.

xxxii. Action Plan for identification of local employable youth for training in skills, relevant to the project, for eventual employment in the project itself shall be formulated and numbers specified during construction & operation phases of the Project

CSR Action Plan (2016-20) was prepared through SoulAce Consulting Pvt. Ltd, Gurgaon, OTPC has already implemented the plan. The implementation status and proposed CSR Plan for budget for the next five years (2019-20 to 2023-23) is provided in Section 9.3.9.

xxxiii. If the area has tribal population it shall be ensured that the rights of tribal are well protected. The project proponent shall accordingly identify tribal issues under various provisions of the law of the land

The need assessment study was conducted for tribal population and other population in the targeted villages and accordingly CSR plan was prepared.

xxxiv. A detailed CSR plan along with activities wise break up of financial commitment shall be prepared. CSR component shall be identified considering need based assessment study and Public Hearing issues. Sustainable income generating measures which can help in upliftment of affected section of society, which is consistent with the traditional skills of the people shall be identified. Separate budget for community development activities and income generating programmes shall be specified

The activity wise detailed CSR budget prepared for the next five years (2019-20 to 2023-23). Public hearing action plan has been prepared considering the socio-economic issues raised by the local people during PH (Refer Section 7.2.3).

xxxv. While formulating CSR schemes it shall be ensured that an in-built monitoring mechanism for the schemes identified are in place and mechanism for conducting annual social audit from the nearest government institute of repute in the region shall be prepared. The project proponent shall also provide Action Plan for the status of implementation of the scheme from time to time and dovetail the same with any Govt. scheme(s). CSR details done in the past should be clearly spelt out in case of expansion projects

Refer CSR Plan (Annex C & D)


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xxxvi. R&R plan, as applicable, shall be formulated wherein mechanism for protecting the rights and livelihood of the people in the region who are likely to be impacted, is taken into consideration. R&R plan shall be formulated after a detailed census of population based on socio economic surveys who were dependant on land falling in the project, as well as, population who were dependant on land not owned by them

The proposed expansion project will be constructed within existing plant area; no additional land would be required for the project. Therefore, R&R issues are not applicable for this project.

xxxvii. Assessment of occupational health and endemic diseases of environmental origin in the study area shall be carried out and Action Plan to mitigate the same shall be prepared

Impact on occupational health discussed in Section 4.3.15.

xxxviii. Occupational health and safety measures for the workers including identification of work related health hazards shall be formulated. The company shall engage full time qualified doctors who are trained in occupational health. Health monitoring of the workers shall be conducted at periodic intervals and health records maintained. Awareness programme for workers due to likely adverse impact on their health due to working in non-conducive environment shall be carried out and precautionary measures like use of personal equipments etc. shall be provided. Review of impact of various health measures undertaken at intervals of two to three years shall be conducted with an excellent follow up plan of action wherever required.

Occupational health safety management plan is given in Section 9.3.7.

xxxix. One complete season site specific meteorological and AAQ data (except monsoon season) as per latest MoEF Notification shall be collected and the dates of monitoring shall be recorded. The parameters to be covered for AAQ shall include PM10, PM2.5, SO2, NOx, CO and Hg. The location of the monitoring stations should be so decided so as to take into consideration of the upwind direction, pre-dominant downwind direction, other dominant directions, habitation and sensitive receptors. There should be at least one monitoring station each in the upwind and in the pre-dominant downwind direction at a location where maximum ground level concentration is likely to occur

One season site specific meteorological data and ambient air quality data has been collected in the study area (Refer Section 3.2.3)

In case of expansion project, air quality monitoring data of 104 observations a year for relevant parameters at air quality monitoring stations as identified/stipulated shall be submitted to assess for compliance of AAQ Standards (annual average as well as 24 hrs).

OTPC has installed 4 ambient quality monitoring stations within the plant premises. OTPC has been monitored ambient air quality twice a week throughout the year The monitoring results regularly submiited to Regional Office of MoEFCC and TSPCB. The summary results is presented in Section 2.9.5 (Table 2.15).

x1 A list of industries existing and proposed in the study area shall be furnished

There is no other industry in the study area; there are few brick kilns in the study area.


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x1i. Cumulative impacts of all sources of emissions including handling and transportation of existing and proposed projects on the environment of the area shall be assessed in detail. Details of the Model used and the input data used for modeling shall also be provided. The air quality contours should be plotted on a location map showing the location of project site, habitation nearby, sensitive receptors, if any. The windrose and isopleths should also be shown on the location map. The cumulative study should also include impacts on water, soil and socio-economics

Impact on ambient air quality is provided in Section 4.3.2.

x1ii. Radio activity and heavy metal contents of coal to be sourced shall be examined and submitted along with laboratory reports

Proposed expansion project gas based power plant. Coal shall not been utilised as fuel. Therefore, analysis of radio-activity and heavy mental contents of coal is not applicable for this project.

x1iii. Fuel analysis shall be provided. Details of auxiliary fuel, if any, including its quantity, quality, storage etc should also be furnished

The fuel for existing and proposed expansion unit is natural gas. The fuel analysis report is presented in Table 2.2 and Annex 2.4.

x1iv. Quantity of fuel required, its source and characteristics and documentary evidence to substantiate confirmed fuel linkage shall be furnished. The Ministry’s Notification dated 02.01.2014 regarding ash content in coal shall be complied. For the expansion projects, the compliance of the existing units to the said Notification shall also be submitted

The fuel requirement, sourcing is presented in Section 2.8.1. Compliance with notification regarding ash content in coal is not applicable either for existing project or expansion project as project uses natural gas as fuel

x1v. Details of transportation of fuel from the source (including port handling) to the proposed plant and its impact on ambient AAQ shall be suitably assessed and submitted. If transportation entails a long distance it shall be ensured that rail transportation to the site shall be first assessed. Wagon loading at source shall preferably be through silo/conveyor belt

Natural gas is the fuel for the expansion project which shall be transported through pipeline by the ONGC (Refer Section 2.8.1)

x1vi. For proposals based on imported coal, inland transportation and port handling and rail movement shall be examined and details furnished. The approval of the Port and Rail Authorities shall be submitted

Not applicable for this project

x1vii. Details regarding infrastructure facilities such as sanitation, fuel, restrooms, medical facilities, safety during construction phase etc. to be provided to the labour force during construction as well as to the casual workers including truck drivers during operation phase should be adequately catered for and details furnished

Refer Section 2.6.4

x1viii. EMP to mitigate the adverse impacts due to the project along with item - wise cost of its implementation in a time bound manner shall be specified

EMP is provided in Chapter 9 including EMP implementation budget.


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x1ix. A Disaster Management Plan (DMP) along with risk assessment study including fire and explosion issues due to storage and use of fuel should be carried out. It should take into account the maximum inventory of storage at site at any point of time. The risk contours should be plotted on the plant layout map clearly showing which of the proposed activities would be affected in case of an accident taking place. Based on the same, proposed safeguard measures should be provided. Measures to guard against fire hazards should also be invariably provided. Mock drills shall be suitably carried out from time to time to check the efficiency of the plans drawn

Disaster management plan is provided Section 7.1.10.

1. The DMP so formulated shall include measures against likely Fires/ Tsunami/ Cyclones/Storm Surges/Earthquakes etc, as applicable. It shall be ensured that DMP consists of both On-site and Off-site plans, complete with details of containing likely disaster and shall specifically mention personnel identified for the task. Smaller version of the plan for different possible disasters shall be prepared both in English and local languages and circulated widely

Disaster management plan is provided Section 7.1.10.

1i. Detailed scheme for raising green belt of native species of appropriate width (50 to 100 m) and consisting of at least 3 tiers around plant boundary with tree density of 2000 to 2500 trees per ha with a good survival rate of around 80% shall be submitted. Photographic evidence must be created and submitted periodically including NRSA reports in case of expansion projects. A shrub layer beneath tree layer would serve as an effective sieve for dust and sink for CO2 and other gaseous pollutants and hence a stratified green belt should be developed

The existing greenbelt status is presented in Section 2.9.6 and greenbelt management plan is presented in Section 9.3.8.

1ii. Over and above the green belt, as carbon sink, plan for additional plantation shall be drawn by identifying blocks of degraded forests, in close consultation with the District Forests Department. In pursuance to this the project proponent shall formulate time bound Action Plans along with financial allocation and shall submit status of implementation to the Ministry every six months

The greenbelt management plan is presented in Section 9.3.8.

1iii Corporate Environment Policy A Does the company has a well laid down

Environment Policy approved by its Board of Directors? If so, it may be detailed in the EIA report

The company has Environment, Occupational Health and Safety Policy. Provided in Section 9.1.

B Does the Environment Policy prescribe for standard operating process / procedures to bring into focus any infringement / deviation / violation of the environmental or forest norms / conditions? If so, it may be detailed in the EIA

The Environmental policy has a provision for auditing and monitoring system and corrective action (Section 9.1).


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C What is the hierarchical system or Administrative order of the company to deal with the environmental issues and for ensuring compliance with the environmental clearance conditions? Details of this system may be given

The organogram of the company and roles and responsibility is provided in Section 9.2.

d Does the company has compliance management system in place wherein compliance status along with compliances / violations of environmental norms are reported to the CMD and the Board of Directors of the company and / or shareholders or stakeholders at large? This reporting mechanism should be detailed in the EIA report

The company has the system of reporting of non-compliances/ violation of environmental norms (Ref. Section 9.2)

1iv Details of litigation pending or otherwise with respect to project in any Court, Tribunal etc. shall invariably be furnished

There is no litigation and pending court case against the project.

Additional Studies i. Authenticated map showing project site vis-a-vis

location of TrishnaWildlife Sanctuary and Sepahijhala Wildlife Sanctuary along with distance of proposed project from the boundaries of Wildlife Sanctuaries and their associated ESZ by Wildlife Department

The ecological sensitivity map of Wildlife Sanctuary Trishna and Sepahijila Wildlife Sactuay map showing location of OTPC plant and distance from Sanctuary has been authenticated by PCCF office and presented at Annex_3.5 of Annex A.

ii. Bio-diversity and ecology impact assessment study for six months shall be conducted with the involvement of experts specifically familiar with the biota of Tripura/north-east India

Biodiversity and Ecological study has been conducted through Centre from Environment & Development. Kolkata (Refer Section 7.3). The report is attached in Annex B.

iii. Details of composition of gas and quantification of emission details shall be submitted

Gas composition has been provided in Section 2.8.1 and analysis report is provided in Annex 2.4.

iv. Eco-hydrology study assessing the impact of proposed water withdrawal from River Ghumti on downstream biota, agriculture and domestic users shall be carried out by an Institute of National Repute

Eco-hydrological study has been conducted through National Institute of Technology (NIT) Agartala (Refer Section 7.4). The finding of the study is presented in Section 3.2.7. The report is attached in Annex C.

v Need based assessment study shall be conducted by an Institute of National Repute for implementing CSR

OTPC has carried out socio-economic baseline study through SoulAce Consulting Pvt. Ltd, Gurgaon. Agency assessed the impact on livelihood of the local communities and developed the community developmet plan. The report in attached in Annex C. CSR Plan provided under the repeot has been updated by ERM and proposed the CSR budget for the next five years (2019-20 to 2023-23. The summary of the plan is presented in Section 9.3.9 and report is attached in Annex E.


ES-I

EXECUTIVE SUMMARY

INTRODUCTION ONGC Tripura Power Company Ltd (OTPC) was set-up in 2004 jointly by Oil and Natural Gas Corporation (ONGC), Infrastructure Leasing and Financial Services Limited (IL&FS) and Government of Tripura (GoT), to develop the 726.6 MW gas based power plant in Tripura. The total capacity of the plant is 726.6 MW (2 x 363.3 MW). The 1st Unit (363.3 MW) was declared under commercial operation on 04.01.2014 and 2nd Unit (363.3 MW) was declared under commercial operation on 24.03.2015. OTPC planned expansion of power plant with two (2) additional units having total capacity of 726 MW +15%. The proposed expansion project requires Environmental Clearance (EC) from Ministry of Environment, Forest and Climate Change (MoEFCC). M/s ERM India Pvt Ltd. has been engaged by OTPC for conducting EIA study and to support in obtaining environmental clearance (EC). ERM’s NABET Certificate No. NABET/EIA/1619/ RA 0055 issued on June 21, 2017 and valid up to October 31, 2019.OTPC has received an approved Terms of Reference (ToR) from MoEFCC on 06.04.2017. The Public Hearing (PH) was conducted by Tripura State Pollution Control Board (TSPCB) on 4 October 2018. Location & Accessibility The proposed expansion unit will be constructed within the premise of the existing plant. The existing plant is located in village Palatana, Tehsil Kakraban, Gomati District, Tripura State. The plant can be accessed from Udaipur-Kakraban Road. Approximate road distance from Udaipur town is 12 km. The Udaipur town is connected with state capital Agartala by National Highway-44 (NH-44), the approximate distance is 53 km. The nearest Airport is Maharaja Bir Bikram Singh Airport at Agartala is approximately 61.5 km. PROJECT DESCRIPTION Resource Requirement Land: The total land area under OTPC-Palatana plant is 197.15 acres. Additionally, OTPC has also acquired 25.45 acres of land for raw water pipeline corridor and residential colony area. The proposed expansion would involve utilization of 33.1 acre area within the plant; no additional land will be required for the main plant and its ancillary facilities.


ES-II

Water: During the construction phase, 100-125 m3/day water will be required during the peak construction period to meet the demands for construction activities. This water will be sourced from existing water source of the plant. The water requirement for the existing plant is 25320 m3/day. The water requirement for the proposed expansion project is 20400 m3/day. Water for the plant will be sourced from Gumti River. OTPC has obtained permission from Public Works Department (Water Resources), Government of Tripura for withdrawal of 125 MLD water from Gumti River for the plant water requirement. Fuel: The fuel of the existing plant and proposed expansion project is natural gas. The annual average consumption of the gas will be 987-1204 Million Metric Standard Cubic Meters (MMSCM) at 85% PLF which translates into average daily natural gas consumption of 2.7 – 3.3 MMSCM. OTPC has 5.0 Million Metric Standard Cubic Meter per Day (MMSCMD) natural gas allocated by Ministry of Petroleum and Natural Gas (MoPNG) for the project. Out of 5 MMSCMD allocated gas, 2.65 MMSCMD is being used for existing units (1 & 2) and 2.35 MMSCMD is available for the proposed units (3 & 4). OTPC has requested to MoPNG for allocation of additional gas for meeting the shortfall. Manpower: The existing manpower for the plant is 155. After expansion, total man power requirement will be around 235. It is estimated that nearly 500 nos. of worker will be required during peak construction phase of the proposed project. Operational Activity Two number of main power blocks have been envisaged for Unit 3 and Unit 4. The main power block of each unit will consist of one gas turbine (GT), one steam turbine (ST) and a heat recovery steam generator (HRSG) and stack. Gas Turbine, Generator: The gas turbine units will have Dry Low NOx (DLN) combustors suitable for burning natural gas. The GT will be installed within an acoustic, ventilated enclosure with fire detection and protection systems. The associate facilities of GT are (i) Inlet Air System, (ii) Fuel Gas Heater, (iii) Lube Oil System and (iv) Exhaust System. Heat Recovery Steam Generators: The HRSGs will be unfired type with horizontal/vertical gas flow, natural circulation with triple pressure (High, Intermediate and Low pressures) steam generation. HRSG will be provided with 60 m high stack. Steam Turbine: The steam turbine will have non-reheat, condensing type, coupled directly to a two (2) pole cylindrical rotor, closed circuit, air cooled generator. The associate facilities of ST are (i) Lube Oil System and (ii) Condensing Equipment & Auxiliaries.


ES-III

Cooling System: The cooling system will be closed cycle induced draft. Power Evacuation: The power generated from the proposed expansion plant will be evacuated through 400kV switchyard. Start-up Power: The start-up power will be drawn from 2 nos 132/6.6 kV, 25MVA station transformers from the 132 kV switchyard. Pollution Sources: Pollution sources from the plant will be air & noise emission, wastewater generation, and solid and hazardous waste. Potential source of emission during operation phase will be NOx. The proposed plant will be utilising Dry Low NOx burner to minimize the NOx emission to a level less than stipulation (50 ppm for the units burning natural gas) by CPCB/MoEFCC. The proposed power plant would use sweet natural gas (NG), which does not contain any sulphur. Natural gas is a clean fuel and the fuel used is filtered in multi stages and hence the flue gas coming out of main stacks; is expected to contain low PM. The main sources of noise generation from the plant will be from gas turbine, steam turbine, HRSG, air compressor, pumps, cooling towers, etc. Adequate engineering control will be taken to minimise the nose level from operation of compressors, boilers, turbines, etc. The major sources of effluent from the plant will be (i) HRSG blowdown, (ii) cooling tower blow down, (iii) wastewater from DM plant neutralization pit, and (iv)wash water, etc. Effluent will be treated in RO and ETP; and treated water will be utilised in the plant. Plant will achieve the zero discharge for proposed expansion unit. Hazardous waste in the form of used oil, oily cotton waste and spent resin will be generated. The waste will be stored and disposed as per Hazardous Waste Management Rules 2016 or any ammendmends thereafter. BASELINE ENVIRONMENTAL STUDIES An area of 10 km from the boundary of the proposed project site has been considered for the baseline studies. The baseline data obtained by primary monitoring/survey and review of secondary information has been summarized below: Land Use: The predominant land use-land cover of the study area includes rubber plantation (37.72%), agricultural land (27.48%), settlement & homestead plantation (22.75%), natural forest (10.36%), river (0.86%), waterbody (0.25%), etc. Soil Quality: The soil samples were collected from five locations in the study area. The pH level in soil sample was 4.9 to 6.15 indicating moderate to slightly acidic soil. Available nitrogen, phosphorus and potassium contents varied


ES-IV

between 134 mg/kg to 268 mg/kg; <3 mg/kg to 6.5 mg/kg and 30 mg/kg to 70 mg/kg respectively. Also soil quality does not indicate contamination from any external source. Natural Hazards: Tripura lies in Zone V, the most severe seismic zone. The state experiences moderate to large magnitude earthquakes. In Tripura flooding of river during monsoon and flash floods in hill areas is commonly experienced. Ambient Air Quality: Monitoring of air quality was conducted at 8 monitoring locations in the study area during pre-monsoon season. The monitored average PM10 concentration varied from 55.33 g/m3 to 66.08 μg/m3. The monitored average PM2.5 concentration varied from 26.04 g/m3 to 31.33 μg/m3. Also all other air quality parameters (SO2, NO2, CO, O3, Hg, etc.) monitored near the project site were found below the NAAQS. Ambient Noise Quality: The baseline noise monitoring in the study area was carried out at 8 locations in the vicinity of the project site. The day time equivalent noise level (Leq day) varied from 42.0-53.8 dB(A) while night time equivalent noise level varied from 37.6-43.7 dB(A). The day time equivalent noise level (Leq day) in the plant area was 66.0 dB(A) while night time equivalent noise level was 53.1 dB(A). Surface Water Resource: Gumti River is the main river in the study area. The surface water uses in the study area of River Gumti are irrigation (lift irrigation), domestic uses (bathing and washing) and fishing. OTPC Palatana plant is also sourcing the river water for its existing plant. The eco-hydrological study has been conducted through National Institute of Technology (NIT) Agartala. The study reveals that the pre-monsoon season water level in the downstream of OTPC intake well was 0.70 m to 3.40 m and during monsoon season the water level was varied from 1.80 m to 3.90 m. Total discharge of the river Gumti near the intake point is 1096.32 million m3/year. Total water available in river Gumti after all the consumption and losses is 533.00 million m3/year. Annual water requirement of the OTPC plant after expansion will be 10.62 million m3/year; i.e. 0.97% of the total annual discharge. It is estimated that about 49.72% of water considering the 10 years growth (irrigation, domestic use, water supply) is available for downstream from intake point after all consumption. Surface Water Quality: Surface water quality was analysed from three locations (Gumti River and nala). The pH of the samples varied from 7.43-7.79. DO levels varied from 6.0 to 6.4 mg/l. BOD level varied from <2.0 to 2.9 mg/l. The total Coliform count of the surface water samples found between 350 to 920 MPN/100 ml. The surface water samples were in compliance to the criteria for propagation of fish and wildlife (Class D). Ground Water Resources: The use of ground water in the district is mainly through dug wells, dug-cum-bore wells, bore wells & shallow tube wells. Ground water is mainly used for domestic and irrigation purpose. The stage of


ES-V

ground water development in the South Tripura was 4.0%, which is categorised as safe block. Ground Water Quality: A monitoring network consisting of 6 locations for ground water was selected within the study area. pH was varied from 5.61-8.13. Total hardness in the groundwater samples varied from 19.6 mg/l to 88.0 mg/l, exceeding the acceptable limit of IS 10500-2012 standards i.e., 200 mg/l. Free residual chlorine in all the six ground water sampling location were found below detectable limit. Concentration of iron in all the ground water samples varied between <0.05-0.43 mg/l. Concentration of heavy metals like Mercury, Cadmium, Lead and Chromium in the ground water sample was below the acceptable limit of IS 10500-2012. Biological Environment: The study area has natural ecosystem like forests in the hills, mostly moist-deciduous, East Himalayan Lower Bhabar Sal in nature. The modified habitats in the study area are plantation (rubber), agricultural lands, homestead plantation. The aquatic ecosystem includes riverine, pond, marshy areas. The Trishna Wildlife Sanctuary is located approximately 7.74 km from plant boundary. The State Govt. of Tripura has been proposed 0.5 km ecosensitive zone (ESZ) around the wildlife sanctuary for Trishna Wildlife Sanctuary. Projetc site does not fall in the Draft ESZ of Trishna Wildlife Sancturay. The mammals in the study are represented by mongoose, jackal, civet, squirrel, rats, mice, bats etc. The bird species are represented by shikra, black kite, mynas, dove, pigeon, barbet, owl, drongo, woodpecker, flycatcher, crows, babbler, oriole, sunbird, sparrow, bea-eater, lapwing, etc. The reptiles are represented by varanus, cobra, krait, rat snake, etc. Gumti River is known for richness of fishes. A total number of 70 species of fishes have been recorded/ reported from the study area. Socio-economic Environment: The project footprint spread across 28 census villages, 3 census towns and 1 Nagar Parisad (Udaipur). The total population in the study area was 1,70,326. The overall literacy and female literacy rates in the core zone (2 km around the plant) were reported to be 90.21% and 85.82% respectively. The overall literacy and female literacy rates in the buffer zone (area between 2.0 km to 10 km around the plant) were reported to be 94.26% and 85.82% respectively. The WPR in the core area was reported to be 37.4% as compared to 38.0% in the buffer area. The major occupations in the study area are agriculture, commercial plantation, wage labour, livestock rearing. IMPACT ASSESSMENT The potential impacts of the project on different components of the environment are systematically identified for evaluation of significance. Impact on Ambient Air Quality: During construction phase, the sources of emission will be fugitive emission from construction material handling, earth


ES-VI

work, and emission from machinery and vehicles. The pollutant especially particulate matter will be settled in areas surrounding proposed project site, however this activity will take place during the construction phase only. The impact in this respect is assessed to be of minor significance. During operational phase, the sources of air emission will be NOx and PM from exhaust gas coming out from gas turbine released in atmosphere through stack after passing through HRSG. The dry low NOx burner will be utilised to control the NOx emission. Natural gas is a clean fuel and the fuel used is filtered in multi stages and hence the flue gas coming out of main stacks; is expected to contain low PM. The impact in this aspect is assessed to be of moderate significance. Impact on Noise Quality: The major sources of noise emission during construction phase are operation of machineries, vehicles, backup DG sets. It is assessed that noise will be attenuated within 200-300 m from construction site. The impact on this aspect is assessed to be of minor significance. During operational phase, the sources of noise emission are operation of gas turbines, generators, HRSG, compressor, boiler, pumps, and cooling tower and backup DG sets. It is assessed that noise will be attenuated within 500-600 m from plant site. The impact on this aspect is assessed to be of minor significance. Impact on Surface Water Quality: The domestic waste water from construction site will be treated through septic tank and soak pit. The surface runoff from construction site during rainy season will be channelized into existing storm water drainage system and same will treated through sedimentation tank; runoff water will be stored in the raw water reservoir for use in the process. The impact on surface water quality is assessed to be minor. During operational phase, the process effluent generated from the plant will be treated through RO plant and ETP and same will be utilised in the process and greenbelt plantation. The domestic waste water from plant will be treated through STP and treated water will be utilised in greenbelt plantation and landscaping area. The surface runoff from the plant during rainy season will be channelized into existing rainwater harvesting pit; the harvested water will be stored in raw water reservoir. The potential impact on surface water quality due to surface runoff is assessed to be minor. Impact on Surface Water Resource: During construction phase, the required quantity of water (100-120 KLD) will be sourced from existing supply of OTPC plant. No impact is envisaged on surface water resources during construction phase. The additional water requirement for proposed expansion project will be 20400 m3/day. The Hydrological study conducted by NIT, Agartala reveals that surface water is available at downstream of OTPC’s intake point of Gumti River. The proposed additional water withdrawal may not cause significant


ES-VII

change of availability of water to downstream users. The potential impact on surface water resource due to sourcing of water is assessed to be moderate. Impact on Ground water Quality: Possibility of ground water contamination from accidental spillage of fuel, lubricants and chemicals from storage areas, vehicles and machinery shall be contained through spill management. Impact significant is considered minor. Potential Impact on Terrestrial Habitat: The construction phase will not involve any felling of trees, as expansion units will be constructed within the available land of main plant site. The greenbelt within the project site is expected to arrest fugitive emissions generated during construction phase. The increased level of noise and vibration in and around proposed project site will cause minimal disturbance to local faunal species. The impact on the terrestrial flora and fauna is assessed to be minor. The increase of NOx emission from proposed expansion unit may not cause significant impact on ecosystem and vegetation. The impact on flora and fauna due to process emission from the plant is assessed to be minor. Potential Impact on Aquatic Habitat: Discharge of surface runoff from construction site with high sediment load to Gumti River has the potential to affect the water quality of the river by increase in turbidity. To contain this surface runoff from construction site will be channelized to rainwater harvesting structure. Withdrawal of water from Gumti River may not cause significant change of downstream water level. This may not cause significant impact on aquatic ecosystem. The potential impact on aquatic habitat is assessed to be minor. Potential Impact on Socio-economic Environment: The proposed expansion project will generate only incremental employment; however, the indirect opportunities due to the increase in residents of the township will generate employment, especially in the immediate vicinity of the site for manual/casual labour and services. Employment generation during construction and operations phase is a positive impact. ALTERNATIVE ANALYSIS The ‘No Project Scenario’ is likely to have a negative effect on opportunities for employment, both directly from the proposed power project and its dependant sectors such as agriculture, industries and manufacturing that require stable power supply in order to operate effectively and be competitive. The site location is well suited for setting up of power plant with availability of adequate availability of land, water, access to road, fuel source/supply arrangement.


ES-VIII

The project design has considered embedded pollution control systems, which include NOx control, stack height for dispersion of pollutants, use of cleaner primary fuel (natural gas). ENVIRONMENTAL MONITORING PROGRAM Environmental monitoring will help in:

Assessing the changes in environmental conditions, Monitoring the effective implementation of mitigation measures, Measuring any deterioration of environmental quality for further preventive action(s).

The following monitoring programs are to be carried out at project in order to meet the above objectives:

Ambient air and noise, water, soil quality Emission and discharge from the plant Greenbelt; Social parameters; HSE Audits; and Inspection of Prevention and Control Measures.

ADDITIONAL STUDIES Risk Assessment Risk assessment was carried out for release of natural gas from pipeline supplying the power house from gas receiving facility to boiler leading to jet fire. The worst hazard for release and ignition of natural gas from the pipeline rupture will be experienced to a maximum radial distance of 25m from the source with potential lethal effects within 1 minute. OTPC has onsite emergency plan to mitigate any emergency situation in the plant. Public Consultation Public consultation was carried out with the objective of finding out about their views and opinion on issues relating to the project, its operations and also to the peripheral development. Public Hearing was conducted by Tripura State Pollution Control Board (TSPCB) at the Plant site on 4th October 2018 as per defined procedure in EIA notification 2006, its amemndments thereafter and based on Draft EIA report submitted to TSPCB for conduct of Publci Hearing. The issues and opinion of the stakeholders during consultation and Public Hearing are addressed in the Public Hearing action plan, socio-economic management plan and CSR Plan. Biodiversity & Ecological Study As per approved ToR, two season biodiversity and ecological study was conducted through Centre for Environment and Development, Kolkata. The study report is included in the ecological baseline and impact section of the EIA report.


ES-IX

Eco-hydrological Study As per approved ToR, Eco-hydrology study was conducted through National Institute of Technology (NIT) Agartala. The impact of proposed water withdrawal from River Gumti on downstream biota, agriculture and domestic users has been incorporated in the EIA report. CSR Plan OTPC engaged ‘SoulAce’ – a specialized CSR firm to undertake needs assessment study across 10 villages situated at the periphery of the plant. The CSR plan has been updated as per ToR requirement. PROJECT BENEFIT The OTPC existing unit and proposed expansion unit has been beneficial with respect to availability of physical and social infrastructure, livelihood generation and other benefits. ENVIRONMENTAL MANAGEMENT PLAN Site-specific Environment Mitigation Measures to prevent and mitigate major/significant adverse impacts and accentuate beneficial impacts will include: Air Quality Management Plan

The covered storage shall be provided for construction materials such as cement, sand aggregates etc.; Regular maintenance of machineries, equipment's and vehicles shall be carried out to control emission; The site approach road will be maintained to minimize emission; The proposed plant will utilise Dry Low NOx / equivalent burners to minimize the NOx emission to a level less than stipulation by CPCB/ MoEFCC. Stacks having sufficient heights shall be provided as per statutory norms to ensure dispersion of pollutants. Continuous Emission Monitoring System (CEMS) will be provided; All the units will be maintained / operated properly at optimum efficiency.

Noise Quality Management Plan

Periodic preventive maintenance of operational units will be undertaken in accordance with instructions of OEM provided in O&M manual; Periodic monitoring of ambient noise quality near sensitive receptors will be undertaken to ensure compliance with regulatory standards; Personnel deployed near high noise generating areas will be equipped with proper PPEs (ear plugs etc.) and subjected to rotation; and Periodic health surveillance programs shall be organized to monitor the health of workers.


ES-X

Solid & Hazardous Waste Management Plan Construction waste will be utilized in the backfilling of the low-lying area of the plant or will be disposed in the designated waste disposal site. Municipal waste will be disposed in the MSW disposal site of Udaipur town; The used oil shall be stored in designated area and periodically sent to registered used oil recyclers/ facilities.

Waste Water & Effluent Management Plan

All the effluent generated from process will be channelized to ETP for treatment; Treated effluent will be recycled and reused in the plant to achieve the zero discharge. Domestic waste water will be treated through STP; and treated water will be utilized in plantation.

Storm Water Management Plan

Additional drainage structures will be created at the construction material handling site. Necessary measures will be undertaken during construction phase to prevent earth and stone material from blocking drainage structures. Periodic cleaning will be undertaken of cross drainage structures and road drainage system to maintain uninterrupted storm water flow. Surface runoff water from plant will be harvested through rainwater harvesting structures; harvesting water will be stored in the raw water reservoir for use in the plant.

Occupational Health & Safety Management Plan (OHSMP)

Training programs will be conducted for the workforce regarding proper usage of Personal Protection Equipment (PPE)’s, handling and storage of fuels and chemicals, etc.; Hazardous and risky areas, installations, materials, safety measures, emergency exits, etc. shall be appropriately marked; All chemicals and hazardous materials storage container will be properly labelled and marked. Materials Safety Data Sheets (MSDS) or equivalent data/information in local language will be made available to exposed workers and first-aid personnel; No employee will be exposed to a noise level greater than 85 dB (A) for a duration of more than 8 hours per day. Provision of ear plugs, ear muffs etc. shall be made rotation of workers operating near high noise generating areas shall be done; The workplace will be equipped with fire detectors, alarm systems and fire-fighting equipment. Fire safety equipment will be periodically inspected and maintained to provided safe working condition; Health problems of the workers will be taken care of by providing basic health care facilities through medical centre/hospital.


ES-XI

Greenbelt Development Plan: The plant has developed 69 acre greenbelt (i.e 33% of the plant area) within the plant area. Socio-economic Management Plan

People from adjoining areas shall be given preference in employment through local contractors according to the skill sets possessed; The broad areas to be focused under the CSR plan would include: Health - arranging mobile health camps including eye camps, School school health programmes which includes free dental awareness examination camps and free check-ups of the students; universal immunization programme etc. Education - providing financial assistance to education institutions towards educational programs, etc. Funding for sports, cultural events etc.

Project Cost and EMP Implementation Budget Total cost of implementation of EMP during construction phase would be around INR 19.69 lakh. The EMP budget under environment & ecology during operational phase would be around INR 632.5 lakhs. The CSR budget for 5 year plan period is 895 lakh.

EXECUTIVE SUMMARY I

1 INTRODUCTION 1

1.1 BACKGROUND ABOUT THE PROJECT 11.2 NEED OF THE PROJECT 11.3 PURPOSE OF THE EIA STUDY 61.4 SCOPE OF THE EIA STUDY 61.5 LIMITATIONS 71.6 LAYOUT OF THE REPORT 7

2 PROJECT DESCRIPTION 9

2.1 INTRODUCTION 92.2 PROJECT LOCATION AND ACCESSIBILITY 92.2.1 Location 92.2.2 Accessibility 92.3 ENVIRONMENTAL SETTINGS OF SITE AND SURROUNDING 142.3.1 Existing Facility of Plant 142.4 LAND USE OF THE PLANT 182.5 LAND AVAILABILITY 202.5.1 Power Block Area 202.5.2 Control Room 202.5.3 Switchyard 212.5.4 Fuel Gas Area 212.5.5 Cooling Tower Area 222.5.6 Water System Area 232.5.7 Laydown area for Phase II Project Equipment 242.6 PROJECT CONSTRUCTION ACTIVITY 272.6.1 Site Preparation 272.6.2 Construction of Plant Units 272.6.3 Resource Requirement: Construction Phase 282.6.4 Construction Schedule 282.7 DESCRIPTION OF OPERATION PROCESS 302.7.1 Plant Configuration 302.7.2 Main Plant 302.7.3 Mechanical Auxiliary System 322.7.4 Power Evacuation 362.7.5 Start Up Power for the Proposed Project 362.8 RESOURCE REQUIREMENT: OPERATIONAL PHASE 362.8.1 Fuel 362.8.2 Water 382.8.3 Manpower 402.8.4 Solar Energy Utilization 402.8.5 Materials Storage and Handling 432.9 POLLUTION SOURCES, CHARACTERIZATION AND CONTROL MEASURES 432.9.1 Air Emission 432.9.2 Noise Emission 452.9.3 Waste Water 46

2.9.4 Solid and Hazardous Waste 522.9.5 Monitoring System 522.9.6 Greenbelt Plantation 542.10 PROJECT COST 572.11 PRESENT STATUS OF COMPLIANCE 57

3 ENVIRONMENTAL BASELINE STUDY 59

3.1 INTRODUCTION 593.2 PHYSICAL ENVIRONMENT 613.2.1 Land Environment 613.2.2 Natural Disaster 703.2.3 Air Environment 713.2.4 Ambient Noise Quality 833.2.5 Traffic and Transport 853.2.6 Water Environment 863.3 BIOLOGICAL ENVIRONMENT 1003.3.1 Introduction 1003.3.2 Objectives of the Study 1003.3.3 Methodology 1003.3.4 Terrestrial Ecosystem 1033.3.5 Aquatic Ecosystem 1253.3.6 Agricultural Diversity 1283.4 SOCIO-ECONOMIC ENVIRONMENT 1283.4.1 Methodology for Socio-economic Study 1283.4.2 Administrative Setup 1293.4.3 General Socioeconomic Profile 1303.4.4 Basic Amenities and Infrastructure 1353.4.5 Cultural and Historical Sites 137

4 IMPACT ASSESSMENT AND MITIGATION MEASURES 138

4.1 IMPACT ASSESSMENT METHODOLOGY AND APPROACH 1384.2 IDENTIFICATION OF POTENTIAL IMPACTS 1444.3 POTENTIAL IMPACT 1474.3.1 Potential Impact Aesthetic and Visual 1474.3.2 Potential Impact on Ambient Air Quality 1494.3.3 Green House Gas Emissions 1574.3.4 Potential Impact on Noise Quality 1594.3.5 Potential Impact on Road & Traffic 1654.3.6 Potential Impact on Land Use 1674.3.7 Potential Impact on Soil Quality 1674.3.8 Potential Impact on Surface Water Resource 1694.3.9 Potential Impact on Surface Water Quality 1704.3.10 Potential Impact on Ground Water Resources 1734.3.11 Potential Impact on Ground Water Quality 1734.3.12 Potential Impact Terrestrial Habitat 1754.3.13 Impact on Aquatic Habitat 1774.3.14 Potential Impact on Socio-economic Environment 1794.3.15 Potential Impact on Occupational Health & Safety 1824.3.16 Potential Impact on Community Health and Safety 185

5 ALTERNATIVE ANALYSIS 188

5.1 NO PROJECT SCENARIO 1885.2 SITE ALTERNATIVE 1895.2.2 Conclusion 190

6 ENVIRONMENTAL MONITORING PROGRAM 191

6.1 IMPLEMENTATION OF THE ENVIRONMENTAL MONITORING PROGRAM 1916.1.1 Internal Monitoring 1916.1.2 External Monitoring & Auditing 1926.2 ENVIRONMENTAL MONITORING PROGRAM & SCHEDULE 193

7 ADDITIONAL STUDIES 198

7.1 RISK ASSESSMENT & DISASTER MANAGEMENT PLAN 1987.1.1 RA Study Objective 1987.1.2 RA Methodology 1987.1.3 Safety Controls Proposed for Natural Gas Supply Pipeline 1997.1.4 Hazard Identification 2007.1.5 Frequency Analysis 2027.1.6 Consequence Analysis 2057.1.7 Disaster Management Plan 2127.1.8 Emergency Identified 2127.1.9 Emergency Classification 2137.1.10 Onsite Disaster Management Team & their Responsibility 2157.1.11 Emergency Resources Available 2167.2 PUBLIC CONSULTATIONS 2207.2.1 Stakeholder Identification 2207.2.2 Stakeholder Consultation 2207.2.3 Public Hearing 2237.3 BIODIVERSITY & ECOLOGICAL STUDY 2287.4 ECO-HYDROLOGICAL STUDY 2287.5 CSR PLAN 229

8 PROJECT BENEFITS 230

9 ENVIRONMENTAL MANAGEMENT PLAN 231

9.1 INTRODUCTION 2319.2 ENVIRONMENT MANAGEMENT FRAMEWORK AND PLAN 2319.2.1 Organizational Role and Responsibility 2319.3 ACTION PLANS UNDER EMP 2359.3.2 Air Quality Management Plan 2369.3.3 Noise Quality Management Plan 2389.3.4 Solid and Hazardous Waste Management Plan 2409.3.5 Waste Water & Effluent Management Plan 2419.3.6 Storm Water Management and Rainwater Harvesting Plan 2439.3.7 Occupational Health & Safety Management Plan (OHSMP) 2459.3.8 Greenbelt Plan 2479.3.9 Wildlife Conservation Plan 248

9.3.10 Socio-economic Management Plan 2499.4 EMP IMPLEMENTATION BUDGET 254

10 SUMMARY AND CONCLUSION 257

11 DISCLOSURE OF CONSULTANTS 261

11.1 ERM’S ACCREDITATION AS EIA CONSULTANT 26111.2 EIA TEAM 261

LIST OF TABLES

Table 1.1 Power Position- North eastern Region 3Table 1.2 Content of the Report 7Table 2.1 Existing and Proposed Land Use and Land Cover of Project Site 18Table 2.2 Fuel Gas Analysis 37Table 2.3 Water Requirement for the Project 38Table 2.4 Water Balance for Existing & Proposed Plant 39Table 2.5 Chemicals and Storage Capacity 43Table 2.6 Potential Pollutant and Mitigation Measures during Construction Phase 43Table 2.7 Air Emission from Existing and Proposed Units 44Table 2.8 Typical Noise Emission from Construction Machinery 45Table 2.9 Typical Noise Emission from Plant Equipment 45Table 2.10 Plant Effluent and Disposal 46Table 2.11 Characteristics of Treated Effluent 49Table 2.12 Characteristics of Treated sewage 50Table 2.13 Hazardous and E-waste Waste Generation, Storage and Disposal 52Table 2.14 Environmental Monitoring System for Existing plant and Expansion project 52Table 2.15 Air Quality Monitoring Results, carried out by OTPC for EC compliance 53Table 2.16 Greenbelt Plantation at Site 56Table 2.17 Breakup of Project Cost 57Table 3.1 Land Use and Land Cover in Study Area 64Table 3.2 Soil Sampling Locations in the Study Area 66Table 3.3 Soil Quality Monitoring Results 69Table 3.4 Significant Earthquakes in Tripura 70Table 3.5 Major floods in the state of Tripura 71Table 3.6 Air Monitoring Locations 75Table 3.7 Summary of Ambient Air Quality Monitoring Results 82Table 3.8 Noise Monitoring Locations 83Table 3.9 Ambient Noise Quality in the Study Area 84Table 3.10 Traffic Values observed in the Project study area 85Table 3.11 Pre-monsoon and Monsoon Water Level 89Table 3.12 Consumption of Water from Gumti River in Study Area 90Table 3.13 Surface Water Quality Analysis 92Table 3.14 Groundwater resources in different part of Tripura 93Table 3.15 Ground Water Monitoring Location 95Table 3.16 Groundwater Monitoring Results 98Table 3.17 Vegetation Types in the Study Area 103

Table 3.18 Phytosociological Characteristics of Tree Species 106Table 3.19 Phytosociological Characteristics of Shrub Species 110Table 3.20 Phytosociological Characteristics of Herb Species 112

117Table 3.22 Information of Butterflies & Moths collected for the study area 119Table 3.23 Diversity Index of Butterfly and Moth 122Table 3.24 Amphibians observed/reported from the Study Area 122Table 3.25 Reptiles observed/reported from the Study Area 123Table 3.26 Avifaunal Species observed in the Study Area 123Table 3.27 Mammalian species recorded/reported in the study area 125Table 3.28 Planktonic Diversity Index in the Study Area 127Table 3.29 List of the Villages Located Within the 10 km Study Area 129Table 3.30 List of the Villages Located Within the Area of Impact 129Table 3.31 Demographic Profile of the Villages Located within the Area of Influence 131Table 3.32 Livelihood Profile in the Project Area 133Table 4.1 Magnitude Prediction Criteria 140Table 4.2 Assessing Magnitude of Impact 140Table 4.3 Sensitivity/Importance/ Vulnerability Criteria 142Table 4.4 Impact Identification Matrix for OTPC-Palatana Expansion Project 145Table 4.5 Emission Parameters for the Power Plant with Natural Gas as Fuel 151Table 4.6 Monitoring Locations with respect to the Project 152Table 4.7 Predicted Conc. of NOx & PM at Receptors due to Proposed Project 155Table 4.8 Estimated GHG Emissions from the Plant 158Table 4.9 Predicted Noise Levels at Receptors during Operation Phase II Project 164Table 5.1 Assessment for Alternative Sites 189Table 6.1 Environmental Monitoring Program 194Table 7.1 Frequency Categories and Criteria 202Table 7.2 Primary Gas Pipeline Failure Frequency 202Table 7.3 Primary Failure Frequency based on Diameter Class (1970-2013) 203Table 7.4 Natural Gas Pipeline - Failure Frequency 204Table 7.5 Natural Gas Pipeline –Jet Fire Probability 205Table 7.6 Severity Categories and Criteria 206Table 7.7 Risk Matrix 206Table 7.8 Risk Criteria and Action Requirements 207Table 7.9 Pipeline Risk Modelling Scenarios 208Table 7.10 Emergency Conditions in the Plant 213Table 7.11 Stakeholder Group Categorization 220Table 7.12 Stakeholder Profiles and Opinions 221Table 1.1 Issues discussed during Public Hearing & Action Plan 225Table 9.1 Hazardous Waste Management 241Table 9.2 Recommended Plant Species for Greenbelt with the Plant 247Table 9.3 CSR activity and budget for 2018-19 to 2021-22 252Table 9.4 EMP Implementation Budget for Construction & Operational Phase 254Table 11.1 Professionals Engaged for the EIA Study 262

LIST OF FIGURES

Figure 1.1 Regional Setting Map 2Figure 2.1 Plant Location of Survey of Topo Sheet 10Figure 2.2 Plant Location on Satellite Imagery 11Figure 2.3 Coordinates of the Plant 12Figure 2.4 Site Accessibility Map 13Figure 2.5 Photographs of Existing Facilities 14Figure 2.6 Existing Plant its Facilities 16Figure 2.7 Environmental Setting Map of the Site 17Figure 2.8 Land Use of the OTPC Palatana Plant 19Figure 2.9 Proposed Power Block Area 20Figure 2.10 Proposed Switchyard Area 21Figure 2.11 Proposed Fuel Gas Area 22Figure 2.12 Proposed Cooling Tower Area 23Figure 2.13 Proposed Water System Area 24Figure 2.14 Proposed Power Block Area 25Figure 2.15 Plant Layout Map: Existing & Proposed Facilities 26Figure 2.16 Construction Schedule for Proposed Expansion Project 29Figure 2.17 Water Balance Diagram for Existing Unit 41Figure 2.18 Water Balance Diagram for Proposed Expansion Unit 42Figure 2.19 Schematic Diagram of ETP 48Figure 2.20 Schematic Diagram of STP 51Figure 2.21 Greenbelt Plantation Area 55Figure 2.22 The Snapshot of Existing Greenbelt 56Figure 3.1 Study Area Map 60Figure 3.2 DEM Map of the Study Area 62Figure 3.3 Project Site on Mineralogical Map 63Figure 3.4 Land Use and Land Cover Map of the Study Area 65Figure 3.5 Photographs of Soil Sample Collection 67Figure 3.6 Primary Monitoring Location Map for Soil, Surface Water & Ground Water 68Figure 3.7 Mean Monthly Maximum and Minimum Temperature recorded at Agartala 72Figure 3.8 Rainfall in Gomati District (2007-11) 72Figure 3.9 Annual Wind Speed and Wind Direction (1971-2000) for Agartala 73Figure 3.10 Windrose Diagram of Study Period 74Figure 3.11 Monitoring Location Map: Air, Meteorology and Traffic 77Figure 3.12 Photographs of Air Sampling 78Figure 3.13 Concentration of Particulate Matter (PM10) in Study Area 79Figure 3.14 Concentration of Particulate Matter (PM2.5) in Study Area 79Figure 3.15 Concentration of SO2 in Study Area 80Figure 3.16 Concentration of NO2 in Study Area 81Figure 3.17 Concentration of CO in Study Area 81Figure 3.18 Noise Monitoring Results 85Figure 3.19 Contribution of Different Type of Vehicle at Udaipur-Kakraban Road 86Figure 3.20 Drainage map of Study Area 87Figure 3.21 Water Level Monitoring Location Map 89

Figure 3.22 Photographs of Hydrological Survey and Water Uses 90Figure 3.23 Fluctuation of Groundwater Levels in Study Area 94Figure 3.24 Photographs of Ground Water Sampling 95Figure 3.25 Ecological Study Area and Sampling Location Map 102Figure 3.26 Photographs of Natural Forest 104Figure 3.27 Photographs of Modified Habitat 105Figure 3.28 Distribution of Male and Female Population in Core and Buffer Area 131Figure 3.29 Proportion of SC/ST Population in the Study Area 132Figure 3.30 Sex Wise Literacy Rate in Core and Buffer area 133Figure 3.31 Worker Profiles with in Study Area 135Figure 4.1 Impact Assessment Process 139Figure 4.2 Assessing Significance of Impact due to Proposed Project 142Figure 4.3 Receptor Network and Emission Sources 154Figure 4.4 NOx Isopleths - 24 Hourly Maximum Ground Level Concentrations 156Figure 4.5 PM Isopleths - 24 Hourly Maximum Ground Level Concentrations 157Figure 4.6 Noise Sources and Receptors Location in Topographic Map 162Figure 4.7 Predicted Operation Phase Noise Levels -Daytime & Night Time 162Figure 6.1 ISO Certificate of OTPC 192Figure 7.1 Risk Assessment Methodology 199Figure 7.2 Gas Pipeline Failure – Distribution of Incident & Causes 203Figure 7.3 Natural Gas Release – Potential Consequences 208Figure 7.4 Threat Zone Plot – Natural Gas Pipeline Leak (25mm dia) 209Figure 7.5 Threat Zone Plot – Natural Gas Pipeline Leak (50mm dia) 210Figure 7.6 Threat Zone Plot – Natural Gas Pipeline Rupture 211Figure 7.7 Emergency Classification "Decision Tree" 214Figure 7.8 OTPC Disaster Management Team 216Figure 9.1 OTPC's Environment, Occupational Health & Safety Policy 232Figure 9.2 OTPC-Palatana EHS Organization Structure 233Figure 9.3 Schematic Diagram of Rainwater Harvesting System 244Figure 11.1 NABET Certificate 264

ABBREVIATIONS

ACW Auxiliary Cooling Water AERMOD AMS/EPA Regulatory Model ALARP As Low As Reasonably Practicable AQ Air Quality BOD Biological Oxygen Demand BTG Boiler Turbine Generator CCGT Combined Cycle Gas Turbine CCPP Combined Cycle Power Plant CCW Closed Cooling Water CEP Condensate Extraction Pumps CO2 Carbon dioxide COC Cycle of Concentration COD Chemical Oxygen Demand CSR Corporate Social Responsibility CTG Combustion turbine and generator CTO Consent to Operate CW Contractual Labourer CW Circulating Water CW Cooling Water DEM Digital Elevation Model DG Diesel Generator DM Demineralization DO Dissolved Oxygen EC Environmental Clearance EHS Environment, Health and Safety EIA Environmental Impact Assessment EMP Environmental Management Plan EN Endangered ERM Environmental Resources Management ERP Emergency Response Plan ERT Emergency Response Team ETP Effluent Treatment Plant FGD Focused Group Discussions GCB Generator Circuit Breaker GDP Gross Domestic Product GHG Green-house gas GIS Gas Insulated Substations GLC Ground Level Concentrations GoI Government of India GoT Government of Tripura GT Gas Turbine HFL High Flood Level HP High Pressure HRSG Heat Recovery Steam Generator IBA Important Bird Area IDTC Induced draft cooling towers

IL&FS Infrastructure Leasing and Financial Services Limited IMD India Meteorological Department IP Intermediate Pressure ISO International Organisation for Standardisation IUCN International Union for Conservation of Nature Leq Equivalent Continuous Level to describe sound LNG Liquified Natural Gas LP Low Pressure MLD Million Litters per Day MMSCM Million Metric Standard Cubic Meter MoEFCC Ministry of Environment, Forest and Climate Change MoPNG Ministry of Petroleum and Natural Gas NAAQS National Ambient Air Quality Standards NABET National Accreditation Board for Education and Training NGO Non-Governmental Organisation NH National Highway NOC No-objection certificate NOx Oxides of Nitrogen OHSAS Occupational Health and Safety Assessment System OISD Oil Industry Safety Directorate ONGC Oil and Natural Gas Corporation OTPC ONGC Tripura Power Company Ltd PCU Passenger Car Unit PGCIL Power Grid Corporation of India Limited PM Particulate Matter PP Project Proponent PPE Personal Protective Equipment RA Risk Assessment RF Reserve Forest SO2 Sulphur dioxides SPL Sound Power Level ST Steam turbine STP Sewage Treatment Plant TDS Total Dissolved Solids ToR Terms of Reference TPP Thermal Power Plant TSPCB Tripura State Pollution Control Board UAT User Acceptance Testing UNFCCC United Nations Framework Convention on climate change VOC Volatile Organic Chemicals VU Vulnerable WHO World Health Organisation WLS Wildlife Sanctuary WTP Water Treatment Plant μg Micro gram AC Alternating current amsl Above mean sea level dB Decibel dia Diameter hr Hour

Ha Hectare Kg Kilogram KJ Kilo joules km Kilo metre km2 Square kilo metre kV Kilo volt KWh Kilo watt hour lt Litre m3 Cubic metre mg Mili gram Mm Millimetre MVA Mega volt ampere MW Mega Watt nm Nano metre ppm parts per million psi per square inch Sq. m. Square meter tCO2e Tonnes of equivalent carbon dioxide


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1 INTRODUCTION

1.1 BACKGROUND ABOUT THE PROJECT

Oil & Natural Gas Corporation Ltd. (“ONGC”), a Fortune 500 company of the Government of India, owns significant natural gas reserves in the North Eastern state of Tripura. However, these natural gas reserves were not getting be commercially developed due to low industrial demand in the North-Eastern region. The complexities of logistics and attendant costs limited the economic viability of transportation of gas to other parts of the country where gas was in deficit. After preliminary study in 2004, ONGC Tripura Power Company Ltd (OTPC) was set-up jointly by ONGC, Infrastructure Leasing and Financial Services Limited (IL&FS) and Government of Tripura (GoT), to develop the 726.6 MW gas based power plant in Tripura. The Vision of OTPC is to enhancing generation capacity through an appropriately scaled up model with a diversified presence in both conventional and non-conventional technologies. The Vision Document of OTPC is presented in Annex 1.1. The OTPC power plant is located in village Palatana, Tehsil Kakraban, Gomati District, Tripura State. (Refer Figure 1.1). The total installed capacity of the plant is 726.6 MW (2 x 363.3 MW). The 1st Unit (363.3 MW) was declared under commercial operation on 04.01.2014 and 2nd Unit (363.3 MW) declared under commercial operation on 24.03.2015. OTPC has planned expansion of power plant with two (2) additional units having total capacity of (726MW + 15%).

1.2 NEED OF THE PROJECT

Electricity consumption in India is increasing at a rate faster than over all energy supply. Over the years the installed capacity of Power Plants (Utilities) has increased to 3,49,288 MW as on 31.12.2018 from a meagre 1,713 MW in 1950. An urgent need is felt for a large scale thermal power development programme in an environment friendly manner and also generate electricity at a competitive price at the earliest. The availability of the coal in India is plenty and it is very competitive. But the problem is mining of coal, obtaining coal linkage, high ash content, transportation of coal to the project site and disposal of ash, long gestation period. Hydro & Nuclear power have also not lived up to the expectation.

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Power Supply and Demand Scenario in India

The power demand in the country is increasing rapidly due to rapid industrialization and various initiatives of government e.g. to provide power to all, to provide round the clock power, to convert petrol and diesel vehicles into electrically operated vehicle etc. The capacity addition at the present rate will not be able to meet the projected demand and would result in a power deficit. To mitigate the gap between demand and supply, Govt. of India (GoI) is facilitating large scale capacity additions through public and private investments. Given the current and projected peak load demand and using the indexation of electricity ratio of electricity to industrial growth rate anticipated in the plan, the peak energy demand for the country is expected to reach 2,22,210 MW in 2021-22 & rise up to 3,68,798 MW by 2032. Over the years, the Electricity Industry has made significant progress, Installed capacity has increased from 1700 MW (1950) to 349,288 MW (31st December2018). Annual per capita electrical energy consumption is also increased from16 kWh/annum (1947) to over 1148 kWh/annum (2017-18). Even though there is huge capacity addition in recent periods, demand for electricity currently outstrips supply.The inefficient use of electricity, lead to shortages, particularly at peak times. Recognizing that electricity is one of the key drivers of rapid economic growth and poverty reduction, the Government of India is now encouraging all the resources to augment the capacity addition. Power Supply and Demand Scenario in North-Eastern Region

The peak power demand for north-eastern region is expected to reach 4,151 MW by year 2021-22 and rise up to 8,450 MW by 2031-32. The power position of North-eastern Region is presented in Table 1.1.

Table 1.1 Power Position- North eastern Region

Sl. No. Power Position- NE Region Unit Value 1 Present Peak Avaiilability MW 2520 2 Present Peak Demand MW 2629 3 Shortfall MW 109 4 Power demand forecast at end of FY 2027 MW 6710 5 Additional capacity required per annum MW 465

[Source: CEA EPS Report and Annual Report for 2018] Justification of the Project

Electricity is one of the key enablers for the country’s economic development. Therefore it is necessary that power sector needs to grow for sustainable economic growth. Moreover, with growing economy, the demand for energy will certainly rise, with the help of certainty in policy-level interventions. Besides, human developmental aspects like poverty reduction, employment generation, etc. are also considerably dependent on secure energy supply. Indian power sector is a major consumer of


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energy and it has a significant impact on economic developments and social welfare. Some of the recent policy changes being introduced by government like universal supply obligation, 24X7 power supply being made mandatory for the discoms, Saubhagya scheme among others, are bound to increase the per capita energy consumption. It would result in increase in the electricity demand across the country

The power consumption by domestic consumers is around 25%. It is expected to increase further by the rural penetration. It would further surge the power demand.

Increasing pressure of population and increasing use of energy in different sectors of the economy is an area of concern for India. As per CEA National Electrcitiy Plan, the energy demand is expected to grow at 6.18% till 2021-22.

As on 31st March,2017, share of non-fossil fuel based capacity (Hydro + Nuclear + RES) in the total installed capacity of the country is around 33%. It is expected that the share of non-fossil based capacity will increase to 49.3% by the end of 2021-22 and will further increase to 57.4 % by the end of 2026-27

GoI has shown their keen interest to combat the issue of Global Warming phenomenon. Thus, the Coal based thermal power plant are at negative consideration by GoI.

As per CEA peak demand for North eastern region is 6710 MW for the year 2026-27. The present peak met is 2629 MW (2017-18) as per CEA Report, hence substantial capacity addition is foreseen in order of 465 MW per annum to meet the demand.

In view of the slow growth of the region, special focus has been laid on economic development of North-Eastern Region and Sikkim. Accordingly strategies have been formulated for removal of infrastructure bottlenecks and creating a conducive environment for overall progress of the region including private investment etc.

NER Grid is connected to the National Grid and hence NER power can be pumped to Western /Southern Grid where load deficit is foreseen.

In view of a large capacity addition programme from Renewable Energy Sources, Hydro which are cyclic and seasonal; hence Gas based power stations are required to play vital role by providing balancing power to cater to the variability and uncertainty associated with Renewable Energy Sources. Therefore, suitable measures to ensure timely completion of capacity addition from hydro and adequate supply of natural gas to based power plants needs to be taken.


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The combustion of natural gas produces only a fraction of the nitrogen oxide and carbon dioxide emissions and also results in essentially no particulate matter or sulfur dioxide emissions. Natural gas therefore becomes an attractive "transition" fuel, as the energy supply moves away from polluting sources such as coal and nuclear sources and towards cleaner, renewable technologies.

Most of large industrial complexes/Industrial consumers are keen either to set up their own captive plants or to buy power directly from producers. For those large industrial power consumers quality and un-interrupted supply are more relevant than price. Power Supply is pivotal for them to continue the production. .

This North eastern region vision document 2030 aims to prepare a roadmap for the next 15 years to increase the production of oil and gas in northeast India and outline the necessary investment in the hydrocarbon sector to increase exploration activities. Northeast India will play an important role in achieving this target as it is endowed with huge untapped natural resources.

The region with 98% of its borders with China, Myanmar, Bhutan, Bangladesh and Nepal, northeast India appears to have a better scope for development in the era of globalisation. Against this backdrop, the region must look at economic integration with rest of Asia, particularly East Asia and Southeast Asia. Additionally, the recent Cross Border Draft Policy by the Honbl’e CERC is expected to make Cross Border Power Trading more conducive.

The key to unlocking the region’s potential, therefore, lies in its vast energy resources and their development. India’s economic progress is closely linked to energy demand. As the economy expands, the need for Electrical energy, oil and gas is expected to grow considerably. The Government of India (GoI) has taken several steps in recent years to drive investments and growth across the country. A number of nation-wide initiatives have been announced including Make in India,

The power scenario brings out the fact that there is a deficit in the current scenario as such and there is a requirement for additional capacity. This situation is expected to continue for quite some time indicating the need for capacity addition to reduce the gap between supply and demand. The Government is therefore encouraging both public sector and private sector to set up power plant to ensure adequate availability of power. ONGC, which is also a 50% share holder in OTPC, owns significant natural gas reserves in the North Eastern state of Tripura. In order to optimally utilize the gas available in Tripura, it was decided to set up in Phase I of the project a 726.6 MW Gas based Combined Cycle thermal power plant close to ONGC’s gas fields in the state of Tripura and supply power to the power deficit areas


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of North Eastern States of India. Since viability of transportation of gas from Tripura to other parts of India still remains elusive, in order to further utilize the gas available in Tripura and supply electricity to consumers at relatively lower price, it is proposed to expand the capacity of Palatana power plant by setting up additional two units of total capacity of 726 MW +15%.

1.3 PURPOSE OF THE EIA STUDY

As per the Environmental Impact Assessment (EIA) notification of 14th September, 2006 and its subsequent amendments, prior Environmental Clearance (EC) has to be obtained before modification/expansion of the existing project. The proposed expansion project qualifies under 1(d) of the Schedule to the EIA Notification and is categorised as Category ‘A’ requiring Environmental Clearance from the MoEFCC. ERM India Private Limited (ERM), a Category ‘A’ NABET accredited consultant for the thermal power plant (Certificate No. NABET/ EIA/ 1619/ RA 0055 valid up to Oct. 31, 2019), has been engaged by OTPC to undertake an EIA and EMP study for this proposed expansion project. The proposal for grant of Terms of Reference (ToR) was presented for discussion at the Expert Appraisal Committee (EAC), MoEFCC in their Meeting on 16th March, 2017 and subsequently the ToR for the EIA was issued by the MoEFCC vide No.J-13012/02/2017-IA.I(T) dated 06.04.2017 (Annex 1.2). The EIA study has been conducted as per approved ToR and Draft EIA Report was submitted to Tripura State Pollution Control Board (TSPCB) on 6 August 2018 for Public Hearing (PH). The PH was conduted by TSPCB on 4 October 2018. The Minutes of Public Hearing Metting has been attached in Annex G.

1.4 SCOPE OF THE EIA STUDY

The scope of the EIA study is as follows: To establish the prevailing baseline environmental and socio-economic condition of the study area in the OTPC power plant; To assess environmental and socioeconomic impacts arising out of the proposed expansion project activities; To recommend appropriate preventive and mitigation measures to eliminate or minimize pollution; To identify and propose management plans in terms of good practices that may help in abating environmental or socio-economic impacts due to the project. Additional studies conducted for Biodiversity and Ecological Impact Assessment Study; Eco-hydrological study and Need based assessment study for CSR interventions


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1.5 LIMITATIONS

This EIA study is based on certain scientific principles and professional judgment to certain facts with resultant subjective interpretation. Professional judgment expressed herein is based on the available data and information. This report has been developed based on the project related information provided by OTPC with the assumption that the information gathered is representative for the proposed expansion of the power plant at Palatana. If information to the contrary is discovered, the findings in this EIA may need to be modified accordingly. The impact assessment for the Project is based on the project configuration as described in Section 2 on Project Description. ERM is not engaged in the impact assessment and reporting for the purposes of advertising, sales promotion, or endorsement of any client's interests, or other publicity purposes. The client acknowledges that any report prepared by ERM are for the exclusive use of the client and agrees that ERM's reports or correspondence will not be used or reproduced in full or in part for such promotional purposes, and may not be used or relied upon in any prospectus or offering circular for commercial purposes.

1.6 LAYOUT OF THE REPORT

The report has been structured as per guidelines stated in EIA Notification, 2006 and its amendments thereof. The following sections form part of the report:

Table 1.2 Content of the Report

Sl. No. Section Brief Description

1. Executive Summary Executive Summary of EIA report.

2. Introduction

This section covers project background; regulatory requirement and overview of the project.

3. Project Description

Presents a Description of the Existing and proposed project.

4. Environmental Baseline Study

Includes a description of existing environmental and social baseline conditions covering both existing plant area and surrounding area.

5. Impact Assessment and Mitigation Measures

Includes impact identification through scoping, assessment of impact, mitigation measures and evaluation of significance of residual impacts.

6. Alternative Analysis

This section includes alternatives analysis with no project scenario

7. Environmental Monitoring Program

The environmental monitoring to be scheduled during construction and operation phase is provided


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Sl. No. Section Brief Description

8. Additional studies

Risk assessment and Emergency Response Plan of the plant. Stakeholder assessment as per primary consultation and Public hearing related issues. Biodiversity and Ecological Impact Assessment Study through CES, Kolkatta ; Eco-hydrological study through NIT Agartala and Need based assessment study for CSR by SoulAce and ERM

9. Project Benefits Benefits arising due to proposed project.

10. Environmental Management Plan

This section covers introduction and elements of EMP i.e. planning, implementation, checking and management review.

11. Summary and Conclusion

Presents the overall findings of the EIA study and includes overall justification for implementation of the project and provides explanation of how, adverse effects have been mitigated.

12. Disclosure of Consultants

Provides brief information about ERM and professionals who were engaged for completion of this study.

13 Annexure Annex A: Annexure to EIA study

Annex B:Biodiversity & Ecological Study Report of CES, Kolkatta

Annex C: Eco-hydrology Study Report of NIT Agartala

Annex D: Need based CSR Plan, prepared by SoulAce Consulting Pvt. Ltd,

Annex E: CSR Plan prepared by ERM

Annex F: Rain Water Harvesting Plan

Annex G: PH Minutes of Meeting issued by TSPCB


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2 PROJECT DESCRIPTION

2.1 INTRODUCTION

The proposed expansion of existing 726.6 MW (2 x 363.3 MW) Combined Cycle Gas Turbine (CCGT) Power Project at Palatana, Gomati district of Tripura state will involve the addition of two new units of capacity 363.3 MW +15% each (3rd and 4th units). The existing 726.6 MW project is termed as Phase I and proposed expansion project is termed as Phase II. With the addition of two new units the total proposed capacity of plant would be 1453- 1562 MW (2 x 363.3 MW + 2 x 363.3 MW + 15%). The details regarding project location and settings, description of main plant unit and auxiliaries, resource requirements etc., have been discussed in the subsequent sections.

2.2 PROJECT LOCATION AND ACCESSIBILITY

2.2.1 Location

The existing plant is located in village Palatana; Tehsil Kakraban, District: Gomati, Tripura State. The site is located in the Survey of India Toposheet No. 79 M/7. The Survey of India Dehradun Office communicated that 1:50,000 scale Topographic Map 79 M/7 is frozen/ not available (Refer Annex 2.1: SOI, Dehradun office Communication letter). As the Topographic Map of 1:50,000 scale is restricted for this location, the site location has been indicated on topographic map of 1:250,000 scale (Refer Figure 2.1). The plant location of satellite imagery and coordinates of the plant boundary is delineated on the satellite imagery in Figure 2.3 and Figure 2.3.

2.2.2 Accessibility

The plant can be accessed from Udaipur-Kakraban Road. Approximate road distance from Udaipur town is 12 km. The Udaipur town is connected with state capital Agartala by National Highway-44 (NH-44), the approximate distance is 53 km. The nearest Airport is Maharaja Bir Bikram Singh Airport at Agartala is approximately 61.5 km. The nearest railway station is Udaipur, which is approximately 9.0 km. The site accessibility map is presented in Figure 2.4.


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Figure 2.1 Plant Location of Survey of Topo Sheet


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Figure 2.2 Plant Location on Satellite Imagery


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Figure 2.3 Coordinates of the Plant


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Figure 2.4 Site Accessibility Map


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2.3 ENVIRONMENTAL SETTINGS OF SITE AND SURROUNDING

2.3.1 Existing Facility of Plant

The OTPC-Palatana power plant is located on southern side of the Udaipur-Kakrabon Road. The main gate of the plant is adjacent to Udaipur-Kakrabon Road, towards western part of the plant. The existing power block (Unit I and II) is located in the central part of the site. The switchyard is located on the eastern side of the plant. The surface water reservoir is located in the south eastern part of the site. The raw water treatment unit, clarified water storage and DM unit is located on north-eastern side of the surface water reservoir. The effluent treatment unit is located on north-western side of the reservoir The cooling towers (2 blocks) are located on western and north-western side of the reservoir respectively. Gas receiving facility located north-eastern side of the site. Storage areas are located on western side of the plant. The administrative buildings are located near main gate. Residential unit and Guest house is located on north-western side of the plant. The plant has boundary wall all along the boundary and greenbelt along the periphery of the plant.

Figure 2.5 Photographs of Existing Facilities

Existing Unit Switch Yard

Raw water Reservoir Cooling Tower


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Medical Unit Hazardous Waste Storage Site

Gumti River near OTPC water intake facility Forest on the eastern side of the plant The existing Plant and its facilities is presented in Figure 2.6. The environmental setting of surrounding area is described below:

The plant is located in the Palatana in Gomati district of Tripura, about 12 km from the district headquarter Udaipur. The nearest villages to the plant area Palatana (adjacent at the northern side), Dudhpushkarini (adjacent on southern and eastern side), Kushamara (1.5 km west) and Kakraban (2 km west) etc. Other major settlements in proximity are Amtali, Magpushkarini, Jamjuri, Hurijala etc. The Gumti River is located 2 km north of the plant. Chandrapur Reserve Forest (RF) is located adjacent to the project site at the eastern side. Other reserve forests within 10 km of the plant site include Radhakishorepur RF (northern side) and Garjee RF (southern side) Land cover within 10 km of the plant side include agricultural lands, rubber plantation areas, forest areas, settlements and homestead plantations etc., Trishna Wildlife Sanctuary is located approximately 7.74 km south of the plant site

The environmental setting map of the site is presented in Figure 2.7.


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Figure 2.6 Existing Plant its Facilities


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Figure 2.7 Environmental Setting Map of the Site


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2.4 LAND USE OF THE PLANT

Total area of the site is 197.15 acre i.e. 79.78 ha. As per revenue records, 193.66 acres (78.37 ha) was forest land and 3.49 acres (1.41 ha) of private land. The diversion of 78.37 ha. of forest land for establishment of Gas based thermal power plant was obtained from Tripura Forest Department vide letter No. F. No. 8-60/2005-FC dated 25th April 2006. The Forest Clearance letter is attached as Annex 2.2. The private land was acquired and appropriate compensation was given to entitled land owners. Additionally, OTPC also acquired 25.45 acres (10.30 ha) of land for building a raw water pipeline corridor and a residential colony. Out of 25.45 acres of land; 8.24 acres of the land was under water pipeline, 15 acres under colony, with 2.21 acres being for boundary straightening. The entire 25.45 acres of land was private land. Currently, the project is utilizing 164.5 acre area which include power block area (9.2 acre), switchyard (12 acre), Fuel Gas Area (4 acre), Water System Area (3.5 acre), cooling tower area (4 acre). Admin area and roads and drains cover 3.5 area and 8 acre respectively. The reservoir and greenbelt covers 21.7 ha and 69 acres of area. The proposed expansion would involve utilization of additional 33.1 acre area within the plant site for Phase II power block area (7.7 acre), Phase II switchyard (6.4 acre), additional fuel gas area (4 acre), additional water system area (3 acre), Phase II cooling tower area (4 acre) and additional area for reservoir (8 acre). The land use details of the project site are presented in Table 2.1 and in Figure 2.8.

Table 2.1 Existing and Proposed Land Use and Land Cover of Project Site

Sl. No.

Land use category Existing (acre) Proposed (acre) Total (acre)

1. Power Block Area 9.2 7.7 16.9 2. Switchyard 12.0 6.4 18.4 3. Fuel Gas Area 4.0 4.0 8 4. Water System Area 3.5 3.0 6.5 5. Cooling Tower Area 4.0 4.0 8 6. Reservoir 21.7 8.0 29.7 Total Area for Plant,

Building and Utilities 54.4 33.1 87.5

7. Admin Area 3.5 0 3.5 8. Road & drains 8.0 8.0 9. Landscape & Horticulture 29.15 0 29.15 10. Greenbelt 69.0 0 69.0

Total 164.05 33.1 197.15

[Source: OTPC, DPR]

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2.5 LAND AVAILABILITY

Land required for additional facilities would be allocated within the existing site premises. Additional land outside the site premised would not be required. Details of in-situ land allocation for additional facilities for the proposed expansion project are presented below.

2.5.1 Power Block Area

The Power block for Phase-II project has already been identified for one unit of 363.3 MW in the Plot Plan. The new power block would be allocated at the following areas:

Power blocks for Phase-II can be located to the North of the Phase –I Power blocks. Plant road as shown in Figure 2.9 will be shifted towards North Existing canteen building, Fire station building and fire drill tower will be relocated suitably

Snapshot of proposed Phase –II power block area is shown in Figure 2.9 :

Figure 2.9 Proposed Power Block Area

Proposed Power Block Area (highlighted in red) shown in Google map

[Source: DPR, OTPC]

2.5.2 Control Room

The existing Control room of Phase-I will accommodate the extra space required for Phase II control room.


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2.5.3 Switchyard

Switchyard 400kV for Phase – II (four bays) can be located on the Northern side of the existing Phase– I switchyard. Snapshot showing the Phase-II switchyard is as shown below.

Figure 2.10 Proposed Switchyard Area

Proposed Switchyard Area (highlighted in red) shown in Google map

Space available on the North side of Phase – I switchyard to accommodate Phase – II 400kW switchyard

[Source: DPR, OTPC]

2.5.4 Fuel Gas Area

One gas terminal point at Fuel gas area shall be provided by ONGC to OTPC for Phase-II project. Receiver, scrubber & flow meter for fuel gas for Phase-II shall be accommodated in the Phase-I area. Space available on the eastern side inside the present station can be used for the same. A snap shot of fuel gas area is shown below:


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Figure 2.11 Proposed Fuel Gas Area

[Source: DPR, OTPC]

2.5.5 Cooling Tower Area

Induced draft cooling towers (IDCT) for Unit#3 of Phase-II will be located in the space as identified in the Plot plan for future. Space identified for the IDCT

Space available east of existing facility to accommodate the gas receiver, scrubber etc., for Phase – II

Space for Phase-II gas booster station


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for Unit#4 of Phase-II will be at the back side of the workshop building. Snapshot of the space identified for Phase II IDCT is shown below.

Figure 2.12 Proposed Cooling Tower Area

Proposed Cooling Tower Area (highlighted in red) shown in Google map

[Source: DPR, OTPC]

2.5.6 Water System Area

Water Pre-treatment plant (aerator, clariflocculator etc.) for Phase-II will be located in the space as identified in the Plot plan for future. DM Plant and Effluent Treatment Plant (ETP) for Phase-II will be located in the space as identified in the Plot plan for future. Snapshot of the space identified for Pre-treatment plant for Phase-II is shown below.


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Figure 2.13 Proposed Water System Area

Proposed Water System Area (highlighted in red) shown in Google map

[Source: DPR, OTPC]

2.5.7 Laydown area for Phase II Project Equipment

Lay down are for Phase – II Project equipment can be suitably allotted on the northern side of the plant as shown below.


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Figure 2.14 Proposed Power Block Area

[Source: DPR, OTPC] The plant layout map is presented in Figure 2.15


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Figure 2.15 Plant Layout Map: Existing & Proposed Facilities


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2.6 PROJECT CONSTRUCTION ACTIVITY

2.6.1 Site Preparation

The proposed expansion units will be constructed within the existing plant site. The site is already developed and grading of site involving earth cut /fill will not be required. However during construction of foundations, some earth material will be generated and same will be utilised for construction of surface water reservoir.

2.6.2 Construction of Plant Units

The proposed expansion project will construct the following units with its ancillary facilities:

Construction of 3rd & 4th unit (2 x 363.3 MW + 15%) and following associated facilities within the existing plant site : Main plant area (northern side of the Plant) Switchyard 400 kV (four bays) Fuel Gas Area : One gas terminal point at Fuel Gas area by ONGC Induced draft cooling towers (IDCT) Water System Area: Pre-treatment plant, Aerator, Clari-flocculator, DM Plant and Reservoir

Construction Equipment

The Contractors would bring their own construction equipment. To facilitate site work, project authority would also procure, if required a few useful construction equipment, viz. crawler mounted heavy-duty crane, tractor-trailer, some transport equipment etc. Construction Materials

All the mechanical, electrical, civil and I&C construction materials along with consumables will be procured by the contractors of individual package. Cement and reinforcement materials will be sourced from Agartala/ Guwahati, sand and gravels will be sourced from Agartala. The construction material will be stored with the plant area. The material will be transported through the existing road network. Transportation of Plant & Machineries

The weight and dimensions of the heaviest plant equipment is one of the major criteria in deciding the plant configuration due to transportation constraint. OTPC had already carried out Transportation Logistic Study during the initial stages of implementing Phase I of the Project. The report had confirmed that transportation of heavy equipment weighing up to approximately 300 Tons was feasible through water/road up to Palatana Site and same was established by


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successful transportation of equipments of Phase I. Same route is proposed to be followed for transportation of equipment of Phase II.

2.6.3 Resource Requirement: Construction Phase

Land

For the proposed expansion units will be constructed on land available within the main plant. The proposed expansion units will be constructed on land available within the main plant. No additional land for expansion unit and its ancillary systems will be required. Details of land requirement for Phase II of the project are provided in Section 2.4. Power

The power requirement during construction phase will be met by existing grid supply of plant. The back-up power requirement will be supplied from DG sets of 250-500 KVA capacity. Water

Approximately, 100 m³/day water will be required during peak construction period to meet the demand for construction activities etc. Water would be sourced from the existing water reservoir in the plant which draws water from Gumti River. Manpower

It is estimated that nearly about 500 nos. of worker will be required during peak construction phase of the proposed project. EPC contractor will be involved for construction of plant and installation of machineries. The outside workforce will be housed in labour camps equipped with potable water supply, sanitation, first-aid and recreation facilities. It is envisaged that the project wing of OTPC be headed by an executive in the level of General Manager, who will look after the overall activities in compliance with the project schedule. He would be assisted by a team of senior engineers experienced in various disciplines including technical, administration, staff welfare, finance, safety and security, materials management, traffic and legal affairs. Consultant’s engineers may be engaged to supervise and monitor different technical activities including compliance of codes, standards, safety requirements, quality, progress etc.

2.6.4 Construction Schedule

The construction activity is planned that Unit# 3 will be completed within 36 months and Unit# 4 within 39 months. The construction schedule is presented in Figure 2.16.


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Figure 2.16 Construction Schedule for Proposed Expansion Project


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2.7 DESCRIPTION OF OPERATION PROCESS

In a combined cycle power plant (CCPP) a gas turbine generator generates electricity and the waste heat is used to generate steam to produce additional electricity via steam turbine; this last step enhances the efficiency of electricity generation.

2.7.1 Plant Configuration

Two number of main power blocks have been envisaged for Unit 3 and Unit 4. The main power block of each unit will consist of one gas turbine & generator (GT), one steam turbine & generator (ST), one heat recovery steam generator (HRSG) and one stack.

2.7.2 Main Plant

Gas Turbine, Generator and Accessories

The Gas turbine (GT) operates on Brayton cycle; wherein the ambient air is drawn to compressor through filters and compressed. In combustor, the compressed air is heated by combustion of fuel. The high pressure-high temperature gas from combustor is expanded in turbine section to pressure just good enough to drive the gas through the Heat Recover Steam Generator (HRSG) and stack. The Gas Turbine models for this CCPP will be heavy duty, advanced class type each comprising of multistage axial compressor and a turbine including combustors section. The GT will be directly coupled with generator. The turbine will have multiple stages. The gas turbine units will have Dry Low NOx (DLN) combustors suitable for burning natural gas only. The GT will be installed within an acoustic, ventilated enclosure with fire detection and protection systems. The GT will have all associated ancillary equipment and systems required for the safe, efficient and reliable operation of the unit under Combined Cycle modes. The associate facilities of GT are as follows: Inlet Air System: The inlet air system would consist of a filter house with self-cleaning air filters, ducting and silencer.Air intake silencer will suppress the noise in the intake air system. Fuel Gas Heater: Depending on the fuel gas specification of GT manufacturer, a water bath / steam heater type fuel gas heater would be provided prior to combustor to ensure that no condensate enters the combustor. Lube Oil System: The GT will be provided with lubrication oil system complete with lube oil pumps, lube oil reservoir, and lube oil coolers. Exhaust System: The exhaust system of GT will exhaust the gas into the atmosphere through HRSG.


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Heat Recovery Steam Generators

The HRSGs will be unfired type with horizontal/vertical gas flow, natural circulation with triple pressure (High, Intermediate and Low pressures) steam generation. The HRSGs will have the dry run capability in order to reduce the black-start power consumption. HRSG will have a separate Super-heater, Evaporator and Economizer sections to generate High Pressure (HP), Intermediate Pressure (IP) and Low Pressure (LP) steams. Further, the HRSGs will also have a re-heater section where, the cold reheat steam from the HP turbine after integration with IP steam from IP evaporator will be superheated. HRSG will be provided with internal thermal insulation, platforms and ladders as required. Feed water and steam sampling arrangements as required would be provided. HRSG will be provided with 60 m high self-supporting steel stack to provide for adequate dispersion of flue gases in accordance with the environmental standards requirements. Steam Turbine and Auxiliaries

The steam turbine will be condensing type. The ST exhaust and condenser configuration will be in accordance to manufacturer’s standard design. The ST will be sized to pass the entire quantity of steam generated by the HRSG over the full range of ambient temperatures specified. The associate facilities of ST are as follows: Lube Oil System: The steam turbine would be complete with lube oil and control oil system, jacking oil system, governing system, protection system and gland sealing steam system. The lube oil system of the STG will be provided with online centrifuge system. Condensing Equipment & Auxiliaries: The steam turbine would be provided with a condenser fixed to the turbine exhaust for condensing the exhaust steam from the steam turbine. The condenser would be of radial or axial or lateral configuration with rigid or spring mounting arrangement as per EPC Contractor’s standard practice. The condenser design will be ensured to prevent sub-cooling of condensate below saturation temperature corresponding to respective condenser backpressure under any of the operating conditions. Vcuum pumps or steam jet air ejectors will be provided to maintain the vacuum in the condenser by expelling the non-condensable gases.


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Condensate Extraction Pumps (CEP): CEPs would be provided to pump the condensate from the hot well to Deaerator through the CPH of the HRSG. The condensate extraction pumps will be vertical motor driven centrifugal canister type with flanged connections. Feed Water System: The feed water system will provide sufficient and reliable feed water to the HRSG. The feed water system will include necessary feed water heaters, de-aerators, feed water pumps, control valves and auxiliaries. Chemical Dosing System: Although high purity water will be used as heat cycle make-up, careful chemical conditioning of the feed steam condensate cycle is essential as a safeguard against corrosion and possible scale formation due to ingress of contaminants in the make-up system. Chemical feed system will comprise of the following:

Hydrazine System: Hydrazine solution will be used to deoxygenate / wipe-off traces of dissolved oxygen left over in the feed water after Deaerator. Phosphate Dosing System: To impart desired alkalinity to boiler water and also to safely remove scale-forming compound in water, if any, due to system contamination as non-adherent harmless precipitate, tri-sodium phosphate solution will be added in the boiler drum

2.7.3 Mechanical Auxiliary System

Fuel Conditioning System

The natural gas will be supplied at available pressure by the Gas supply agency. However, gas booster compressor shall be envisaged to meet the pressure requirement of the selected gas turbine. A control valve would be provided to regulate the gas pressure. Necessary conditioning system for natural gas has been envisaged as a part of this project to meet the fuel gas specifications of gas turbine manufacturer. The gas conditioning process generally comprises of removal of condensates, filtration, etc. The gas stream will be provided with knockout drum to remove condensate and a cartridge filter to remove particulate matters in the influent natural gas before admitting to GT. GT will be provided with a final filter to remove the condensate formed during the compression as well as ingress of particulates in compressor and piping system. The final filters will be located close to gas turbines. If required, a hot water bath / steam type fuel gas heater will be provided to ensure the required superheat of gas as well to enhance the plant efficiency. A gas condensate tank of adequate capacity will be provided to collect the gas condensates if any from the conditioning skid / GT.


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Adequate safety features will be built-in into the gas system to protect the operating personal and the property against fire hazards. Adequate no. of purging points with nitrogen supply will be provided to purge the system during maintenance. A common cold stack of adequate height will be provided at safe location in gas conditioning area, to which all the vent lines of gas system will be connected to disperse the system vents during maintenance and safety valve pop-ups. During normal operation, no continuous fuel gas venting is envisaged, hence no hot flare is being provided. Cooling Water System

The proposed power plant being located close to water source, closed cycle cooling water system has been considered for surface condenser of steam-water cycle. Considering the high humidity and being located inland, Induced Draft Cooling Tower (IDCT) is considered to cool the hot return water from Surface Condenser of ST. Cooling Water (CW) pumps shall be provided tp supply cooling water to STG condenser. The CW pumps will be located in a cooling water pump sumps, which will receive cooled return water from the cooling tower basin. The cooling water sumps and CW forebay will be sized as per guidelines of Hydraulic Institute Standard. The make-up for the cooling water system will be from clarified water. The cooling water make-up pumps would start and stop based on level signals from level switches in forebay. To ensure adequate dissolvability of scales, the CW system make-up water requirement is sized based on five (5) cycle of concentration (COC). Chlorine gas dosing system will be provided to prevent formation of algae and other biological growths. The CW chlorination system would comprise chlorine tonners, evaporators, motive water pumps, chlorinators, chlorine gas distribution system, chlorine gas leak absorption system, etc. The chlorination system equipment will be located in a room adjacent to CW Pump house. The Chlorination system will be suitably sized to achieve desired objective. The total number of tonners per block will be based on requirements of 15 days of chlorine requirement of respective block. Auxiliary Cooling Water (ACW) and Closed Cooling Water (CCW) System

The CCW system meets the cooling water requirements of all the auxiliary equipment of the GT, ST and HRSG units such as turbine lube oil coolers, generator coolers, BFP auxiliaries, condensate pump bearings, sample coolers and air compressors auxiliaries. The GT and ST/HRSG auxiliaries will be provided with separate ACW systems since the pressure requirements of cooling water system of GT is generally high when compared to auxiliaries of ST and HRSG.


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The primary side of this cooling water system for auxiliaries, i.e., circulating cooling water (CCW) system will make use the passivated DM water as cooling medium, which will be circulated in closed circuit through plate heat exchanger and auxiliary coolers in series. The hot water from auxiliary coolers in primary circuit will dissipate the heat to cooling water from Condenser cooling water system in secondary circuit. For this purpose, Plate Heat Exchangers (PHE) have been envisaged. The cooling water in secondary circuit (ACW system) will be cooled in turn in IDCT of condenser cooling water system. ACW pumps per circuit will be provided to circulate the water in secondary cycle through plate heat exchanger and IDCT. Central Lube Oil System

The plant will be provided with central lube oil system for the purpose of storing and treatment of lube oil for Steam turbine and auxiliaries. For gas turbine lube oil system, the properties will be monitored at regular interval and will be replaced after the properties deteriorate beyond the recommended values by manufacturer. Fire Fighting System

For protection of power plant equipment and operating personnel against fire, any one or a combination of the following systems will be provided for all yards, areas, buildings and equipment: • Hydrant system – Entire Plant, • Medium Velocity Water Spray System – Cable Gallery, Fuel oil tanks and

EDG building. • High Velocity Water Spray System – Transformers, Lube oil skids and

Hydraulic oil skids, • CO2 / Clean Agent Systems – Switchgear Rooms, Control Rooms, • Sprinkler System for fire water pump house, • Foam cabinets and portable foam system, • Fire resistant doors and fire seal walls will be provided as per code

requirements. • Portable and Mobile Fire Extinguishers – Entire Plant, • Fire detection and alarm system for main control room, Control equipment

room, UPS room, Switchgear room, Cable spreader room, Battery and battery charger room.

The system will be designed generally in conformity with the recommendations of the Tariff Advisory Committee (TAC) of Insurance Association of India. The recommendations of National Fire Protection Association (NFPA), USA / equivalent will be followed, as applicable.


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The source of water for firewater pumps of hydrant network and water spray will be from the clarified water tanks. A reserve water level will be maintained in the sump as per TAC requirements. Adequate number of engine driven firewater pumps & motor driven pumps will provided to cater water to firewater network. In addition to the above, jockey pump sets, hydro-pneumatic tanks, compressors, pipes and fittings as required will be provided. Hydrant system will feed pressurized water to hydrant valves located throughout the plant and also at strategic locations within the powerhouse. Compressed Air System

Plant oil free air compressors of adequate capacity & discharge pressure along with instrument air drying system & compressed air receiver will be provided to cater the plant compressed air requirement. The service air system and the instrument air system will be separate in all respects. Air Conditioning System

Various control rooms in power station houses a group of sophisticated and precision control panel and desks, which require controlled environments for proper functioning. For control rooms, the objective of air-conditioning is to maintain conditions suitable for satisfactory functioning of sophisticated equipment, accessories and controls and also for personnel comfort. Besides these, the service areas viz. instrument and relay testing laboratories chemical laboratory and a few offices are envisaged to be air-conditioned. For major control rooms and other blocks with higher heat loads and which require sophisticated control system, packaged type water cooled chiller with minimum one no. unit as a standby will be provided. Each system will be complete with air handling unit, chiller unit and a dry cooling tower with cooling air fan, associated piping with valves, fittings etc. These air conditioning systems will have interlocks with fire detection system of the respective rooms to trip upon fire signal from detectors. For other areas, packaged air conditioners / split type air conditions as suitable will be provided. Workshop Equipment

Phase-I workshop is proposed to be utilized for Phase-II also. Chemical Laboratory

Phase-I Chemical laboratory is proposed to be utilized for Phase-II also.


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Hydrogen Generation Plant

Phase-I Hydrogen generation plant is proposed to be utilized for Phase-II also.

2.7.4 Power Evacuation

The entire power generated from proposed expansion unit will be evacuated through 400 kV transmission network from project site at Palatana. The power to be evacuated from the proposed expansion project is expected to be in the range of 700-810 MW after accounting for auxiliary power consumption of block 3 & 4. The generators will be connected to the 400 kV switchyard through step-up transformers. A 400kV double circuit transmission line is operating for evacuating power from the existing power plant at Palatana to Silchar (Assam) and Bongaigon (Assam) where PGCIL 400kV substation is located. Ministry of Power, Government of India is setting up a 400 kV grid substation at Surajmaninagar, around 40 km from the proposed project site, and 400 KV D/C transmission line between Surjyamaninagar and Silchar via PK Bari through tariff based competitive bidding. PGCIL has already constructed 400 kV double circuit transmission line from Surajmaninagar Substation to the Palatana power plant which is presently operating at 132kV. Once the 400kV substation work at at Surjyamaninagar is completed, this line will be charged at 400kV level and further connected to Silchar 400kV substation. Each 400kV double circuit lines will evacuate around 1060 MW power. Hence Power evacuation from the project site to the other parts of the northeast region is possible and there are 400kV transmission line network available.

2.7.5 Start Up Power for the Proposed Project

For the existing power plant the start-up power is drawn through 2 nos 132/6.9kV, 25MVA station transformers from the 132 kV switchyard and these station transformers feeds power to the unit buses for starting up of the GTs and STs of both the units. It is proposed to follow Generator Circuit Breaker (GCB) scheme for drawing start-up power. In the GCB scheme start up power shal be drawn through Generator transformer and UAT and generator shall be synchronized using GCB.

2.8 RESOURCE REQUIREMENT: OPERATIONAL PHASE

2.8.1 Fuel

Fuel Requirement

Based on natural gas analysis furnished in this report, the annual requirement of fuel for 2 blocks with 726±15% MW Capacity (Nominal Gross Site Rating) and 85% plant load factor is estimated to be 987-1204 MMSCM per year. The design net calorific value, which has been considered for estimating the fuel gas consumption, is 8250 kcal/Sm3.


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The annual average consumption of the gas will be (considering 85% PLF) 987 to 1204 MMSCM. Average daily estimated gas requirement at site ambient condition is estimated to be 2.70 to 3.30 MMSCMD. OTPC has 5.0 MMSCMD natural gas allocated by MoPNG for the project (Annex 2.3 Gas allocation letter). Out of 5 MMSCMD allocated gas, 2.65 MMSCMD is being used for existing units (1 & 2) and 2.35 MMSCMD is available for the proposed units (3 & 4). OTPC has requested MoPNG for allocation of additional gas for meeting the shortfall. Source and Type of Fuel

Fuel, which has been envisaged for the proposed power plant, is natural gas. Natural gas will be supplied by ONGC through its pipeline from gas wells up to the plant boundary. For the expansion project, Natural gas will be supplied by ONGC from their gas wells at Agartala / Dome, Baramura, Konaban, Sonamura, Tichana, and Gojalia. The natural gas system will include backup metering equipment and all necessary compressors, pressure reduction stations, gas filter-separators, isolation and control valves, safety valves, and other equipment. Fuel Characteristics

The existing and proposed fuel gas is with high Methane and is a sweet gas without compounds of sulphur. The proposed natural gas has been found generally suitable for CCGT power plants after treatment and is also environmental friendly. The composition of natural gas is provided in Table 2.2. The Gas analysis report is attached in Annex 2.4.

Table 2.2 Fuel Gas Analysis

Composition Normal derived

Agartala Dome

Konabon Baramura Sonamura Trichna Gojalia

Methene (CH4) 96.956 96.956 97.068 97.902 97.315 96.08 96.96 Ethane (C2H6) 1.87 1.87 1.816 1.267 2.056 2.76 1.966 Propane (C3H8)

0.409 0.409 0.309 0.352 0.191 0.68 0.204

i-Butane (C4H10)

0.0 0.126 0,082 0,084 0.101 0.16 0.171

n-Butane (C4H10)

0.209 0.083 0.062 0.074 0.055 0.1 0.085

i-Pentane (C5H12)

0.0 0.04 0.017 0.024 0.0 0.04 0.0

n-Pentane (C5H12)

0.064 0.024 0.014 0.019 0.0 0.03 0.0

Hexane (C6H14)

0.14 0.0 0.0 0.0 0.0 0.0 0.0

CO2 0.276 0.276 0.45 0.141 0.21 0.15 0.18 Nitrogen (N2) 0.216 0.216 0.182 0.137 0.072 0.0 0.434 Total 100 100 100 100 100 100 100

[Source: DPR, OTPC]


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2.8.2 Water

Water Requirement: The current operational water requirement of the plant is 25320 m³/day. The expansion project will require additional 20400 m³/day water would be required for functioning of the two new units. Details of breakup of water requirement for the project are presented in Table 2.3.

Table 2.3 Water Requirement for the Project

S No. Units Existing (m³/day)

Expansion Project (m³/day)

1. CW Make-up 23712 24,000 2. DM Water Make-up to HRSG Cycle 864 Existing Plant 3. Evaporation Loss 64 48 4. Plant Service Water System 240 Existing Plant 5. Plant Potable Water System 240 Existing Plant 6. Expected Sludge in the River Water to Plant 200 504 7. Recovery water from Blow down of RO Plant - 3792 8. Recovery of water from Sludge handling

system 360

Total Fresh Water Requirement 25320 20400 [Source: DPR Report] Source of Water: OTPC has obtained permission from Public Works Department (Water Resources), Government of Tripura for withdrawal of 125 MLD water from Gumti River for plant operations. The approval letter is attached as Annex 2.5. The location of existing river water intake point and the pump house is about 2.0 km from the Power Plant Site along the pipeline route. Existing river water intake system is proposed to be Phase II also. Water Supply & Storage: Currently, Four (4) Nos. (3 Working + 1 Standby) vertical River water pumps are operated at 8 hours per day continuous operation to cater the raw water requirement for 24 hours per day of Phase-1 units (i.e. 2x363.3 MW). Each installed pump is capable of developing the required total head i.e. 1100 m3/h. Hence, these pumps shall be operated for 13 hours per day to supply the raw water required for 24 hours operation of Phase-I & Phase-II. The existing raw water storage capacity is 1,78,000 m3. For the proposed expansion considering the availability of land of about 8 acres adjacent to existing reservoir, an additional raw water reservoir to hold about 65,500 m3 will be provided. The proposed additional raw water reservoir will be interconnected with the existing reservoir. The total storage capacity of both the water reservoirs taken together will be sufficient to meet 5 days raw water requirement for Phase-I & Phase II. Water Pre-Treatment Plant A pre-treatment plant will be installed to clarify the raw water. Chemicals such as alum and soda ash will be dosed to the water in flash mixer. The clarified


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water from the over flow of Clarifloculator will be stored in a twin compartment clarified water reservoir of 2 hours storage capacity and will be used for Cooling Tower make-up, service water, potable water and input water to the DM Plant. The sludge from the water pre-treatment plant will be used as manure in horticulture. Water Balance Existing Plant: The total raw water requirement for for existing plant is 25320 m3/day. The evaporation loss at raw water reservoir and sludge generated from raw water treatment is 264 m3/day. Cooling makeup water is 23712 m3/day, service water requirement is 240 m3/day and potable water requirement is 240 m3/day and DM Plant water requirement 864 m3/day. Total effluent generated from the plant (Phase I) is 5858 m3/day. The effluent is being treated in the ETP; part of the treated effluent (1000 m3/day) is being used for landscaping & greenbelt and balance water (4858 m3/day) is being disposed in the Gumti River after meeting discharge standard. Proposed Plant: The total raw water requirement for proposed expansion unit is 20400 m3/day. The evaporation loss at raw water reservoir and sludge generated from raw water treatment will be 552 m3/day (48 + 504 m3/day). Wastewater is adequately recycled to maintain CoC of 5. Cooling makeup water will be 24000 m3/day; out of which 20208 m3/day will be sourced from clarifier water and balance 3792 m3/day from treated water from RO plant. The effluent generated from Phase II (5808 m3/day) will be treated in ETP then RO Plant. ETP Reject (HRSCC +Filter DWF + RO) – 2016 m3/day will be used for Greenbelt & Horticulture. Phase II plant will be operated as zero discharge. The water balance for existing and proposed pant is presented in Table 2.4 and Water balance diagrams for the existing and proposed phases are presented Figure 2.17and Figure 2.18.

Table 2.4 Water Balance for Existing & Proposed Plant

Sl. No.

Water Use Existing Plant (m3/day)

Proposed Plant (m3/day)

A Raw Water Intake 25320 20400 B Evaporation loss at Raw Water Reservoir 64 48 C Raw Water available for Plant (A-B) 25256 20352

D Sludge generated from Raw water treatment plant 200 504

E Recovery of water from Sludge handling system 0 360 F Clarified water (C+ E -D) 25056 20208 G Treated water from RO Plant 0 3792 H Water available for Plant (E+F) 25056 24000 I Cooling Makeup Water 23712 24000 J Service Water 240 From Phase I K Potable Water 240 From Phase I L DM Plant 864 From Phase I M Total Water Requirement for Plant 25056 24000 N Evaporation and Draft Loss at CW Tower 18912 19200 O Cooling Tower Blowdown 4800 4800 P HRSG Blowdown 1008 1008 Q DM Plant Reject 50 -


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Sl. No.

Water Use Existing Plant (m3/day)

Proposed Plant (m3/day)

R Total Effluent generated from Plant (O+P+Q) 5858 5808

S ETP Reject (HRSCC +Filter DWF + RO) used for Greenbelt & Horticulture

1000 2016

T RO treated water use for CW Makeup for Phase II 0 3792 O Discharge into River 4858 0

2.8.3 Manpower

The existing manpower for the plant is 155. After expansion of the capacity 80 additional personnel manpower will be required. The total manpower after expansion will be 235.

2.8.4 Solar Energy Utilization

OTPC –Palatana project has installed solar power street lighting system and solar garden lights within the plant. Presently, there are 5 numbers of solar street lights and 35 numbers of solar garden lights have been installed. It is planned to installation more street lights in the plant. OTPC has also undertaken the Pre-Feasibility study for setting up of solar rooftop PV Power Plants through Solar Energy Corporation of India, Government of India Enterprise. Salient features and recommendations of report are presented hereunder: The salient features and recommendation of the study is presented in following Box.

As per the study report, the OTPC buildings are quite suitable for installation of solar PV roof top plants. As per the area of the roofs available, 1 MW of capacity can easily be installed by considering reasonable size roofs which can accommodate >30 kW. The radiation resource assessment shows that Palatana is having annual global horizontal irradiation of 5.07 kWh/m2/day which is close to country’s average. The maximum temperature of the Palatana, is observed to be vary between 28-36 which is moderate and favourable for solar PV plants where rise in temperate reduces the PV plant performance. Based on the simulations the proposed plant is expected to perform at CUF of around 18 % with annual electricity generation of 1.58 million units. The plant cost is estimated to be approximately 9 crores based on latest market trends and is expected to reduce after bidding. The project can be considered under pilot scheme of MNRE for grid connected roof top PV plants, where 30% of the capital subsidy may be availed.


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Figure 2.17 Water Balance Diagram for Existing Unit


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Figure 2.18 Water Balance Diagram for Proposed Expansion Unit


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2.8.5 Materials Storage and Handling

The plant operation will require chemicals for water treatment and process requirements. A list of the hazardous chemicals which will be used in the Plant and the maximum quantity stored is presented in Table 2.5.1

Table 2.5 Chemicals and Storage Capacity

S. No. Chemical Name Maximum Storage Quantity 1. Hydrochloric Acid 11 m3 2. Caustic Lye 11 m3 3. Sulphuric Acid 30 m3 5. Lube Oil 900 L

Source: DPR 2017 Acids and other hazardous materials will be stored in a dedicated room with adequate ventilation, at the water treatment plant area. Lube oil will be stored in drums. The storage arrangements for all chemicals will include secondary containment for spillage control.

2.9 POLLUTION SOURCES, CHARACTERIZATION AND CONTROL MEASURES

The environmental issues associated with the expansion project will include:

Air emission; Noise generation; Wastewater generation; Generation of solid and hazardous wastes; Generation of hot water

2.9.1 Air Emission

Construction Phase

The potential air pollutants from the construction activities are as follows:

Table 2.6 Potential Pollutant and Mitigation Measures during Construction Phase

Sl. No.

Activity/ Source Pollutants Proposed Control Measures

1. Soil work for foundation of plant

Particulate matter (PM)

Dust suppression measures

2. Handling of construction materials (transport and storage)

Particulate matter (PM)

Proposed to store in covered storage area and material will transported through covered truck

3. Operation of diesel operated machineries, vehicle and back up DG sets

PM, SO2, CO, NO2, HC

Use of PUC vehicles and maintenance of machineries & vehicles.

1Hazardous or toxic materials/waste shall not be imported as raw material for industry.


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Operational Phase

Point Source: The air emission from proposed plant likely to be: Nitrogen oxides (NOx) in flue gas Particulate Matter (PM) in flue gas Sulphur dioxide (SO2) in flue gas

The proposed control measures for the above mentioned pollutants are as follows: NOx Emission: The proposed plant will be utilising Dry Low NOx / equivalent burners to minimize the NOx emission to a level less than stipulation (50 ppm for the units burning natural gas) by CPCB/MoEFCC. PM Emission: For thermal power stations, MoEFCC prescribe a limit of 30 mg/Nm3 for particulate matter, irrespective of generation capacity of the plant. Natural gas is a clean fuel and the fuel used is filtered in multi stages and hence the flue gas coming out of main stack / Bypass stack in the combined cycle modes of operation expected to contain minimal particulate matter. SO2 Emission: The proposed power plant would use sweet natural gas (NG), which does not contain any sulphur. Hence, there would not be any emission of sulphur dioxide in the flue gas. A Continuous Emission Monitoring System (CEMS) will be installed for round the clock monitoring of SO2, NOx, PM and CO level from main stack of HRSGs. The Unit-1 and Unit-2 of Phase I project has already installed the CEMS and same has been connected with TSPCB and RO-MoEFCC server. The one year average CEMS monitoring data for existing unit and design emission level of Phase II unit is presented in Table 2.7.

Table 2.7 Air Emission from Existing and Proposed Units

Pollutants Existing Plant* (ppm) Proposed Plant** (ppm) CPCB/MoEFCC Emission Standard Unit-1 Unit-2 Unit-3 Unit-4

NOx (mg/Nm3) 9.2 to 19.4 12.4 to 17.1 50 50 130.88 (50 ppm) PM (mg/Nm3) 1.7 1.7 30 SO2 (mg/Nm3) Nil Nil Nil Nil 100

[Source: * OTPC- CEMS Data April 2017; **Project Feasibility Report] Line Source: Particulate emissions from movement of vehicles on paved roads & vehicular emissions like PM, CO & HC’s from exhaust of the vehicles are envisaged as line source emissions. Currently movement of project vehicles include approximately 3-4 heavy vehicles, 18-20 light vehicles and 30-35 cars non-motorised vehicles.


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During construction phase approximately, 20-15 trucks/trailers per day would be carrying raw material for construction. For workers 10-15 cars and 20-25 nos. two wheelers will be utilising the same route during peak construction phase During operation phase approximately, 5-6 heavy vehicles per day would be carrying chemical and other materials required for operation. Additionally, movement of 10-15 cars and 40-45 non-motorised vehicles is also anticipated during operational phase for manpower movement. Line Source Emissions Control Vehicles having requisite Pollution Under Control Certificates (PUCC) will only be allowed within the plant. Trucks will be covered with tarpaulin to reduce the spillage of materials.

2.9.2 Noise Emission

Construction Phase

Noise will be emitted from construction site during site preparation, construction activities, movement of vehicles and construction machineries. Noise during the site preparatory phase will primarily be contributed by heavy construction machinery operating on site and vehicular sources. Average noise emission ranges for different types of construction machinery are shown in the table below.

Table 2.8 Typical Noise Emission from Construction Machinery

Equipment Sound Level At Operator (in decibels) Average Range

Front End Loader 88.0 85-91 Back Hoe 86.5 79-89 Bull Dozer 96.0 89-103 Roller 90.0 79-93 Truck 96.0 89-103 Material Handling Equipment Concrete Mixer <85.0 - Crane/Hydra <85.0 -

Source: British Columbia, “Construction Noise,” Workers Compensation Board of BC Operational Phase

Noise generated from different plant equipment currently in operation is presented below.

Table 2.9 Typical Noise Emission from Plant Equipment


Air Compressor 85 Gas Turbine 85 HRSG 85 Steam Turbine 85 Boiler 85


46


Pump 85 Cooling Tower 85

[Source: Project Feasibility Report] Noise Control Measures

Adequate engineering control to minimise the nose from operation of compressors, boilers etc.; Maintenance of greenbelt around the plant premise.

2.9.3 Waste Water

From the proposed expansion project the following wastewater are envisaged: • Waste water from neutralization pits of DM Plant. • HRSG Blowdown. • GT Compressor Wash water Drain System. • Oily Water from Transformer Pits. • Oily Water from Buildings / Areas like lube oil storage tanks, from

equipment maintenance area floor drain, etc. • Cooling Tower Blow down. • Gas Condensates from Gas Conditioning Area. The waste water generation, method of treatment and disposal/ reuse method is presented in Table 2.10.

Table 2.10 Plant Effluent and Disposal

S No Effluents Sources Method of treatment Disposal / Reuse 1. Cooling Tower

& HRSG Blow down

Cooling towers, HRSG

The Cooling Tower blow down will be led to HRSG blow down sump and after mixing with HRSG blow down, the effluent will be sent to CMB, ETP, RO plant for recycling the wastewater.

Recycled in the system

2. Wastewater from neutralizing pits and DM plant

DM Plant Would be sent to CMB and treated in ETP-RO

Recycled in the system

3. Oily wastes Transformer yard, TG hall floor wash

Tilted Plate interceptor, oil skimmer and then to ETO-RO

Treated effluents are reused for horticulture and removed oil is taken offsite for disposal.

4. Industrial waste with high suspended solid levels

Boiler area floor wash Service water wastes

Treatment through Tilted Plate Interceptors and then to ETO-RO

Treated effluents are reused for horticulture and sludge shall be disposed


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S No Effluents Sources Method of treatment Disposal / Reuse 5. Sewage Canteen

Toilets Sewage treatment Plant Treated sewage is

reused for horticulture.

Effluent Treatment Plant

All the effluent from DM plant, HRSG blowdown, Cooling tower blowdown, STG building floor wash, oily waste from transformer yard will be treated in ETPP. Treated effluent from CMB/ Guard Pond will be utilised in the process and for plantation/ green areas. Schematic diagram of ETP is presented in Figure 2.19.


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Figure 2.19 Schematic Diagram of ETP

[Source: DPR, OTPC]


49

Effluent Characteristics

OTPC conducts regular monitoring of quality of wastewater streams and treated wastewater in the plant area and submit the results to Tripura State Pollution Control Board. The results are presented in Table 2.11.

Table 2.11 Characteristics of Treated Effluent

Sl. No. Parameter Observed Value Discharge Standard 1 pH 7.44 to 8.04 6.5 to 8.5 2 SS 6 100 3 Temperature 28 Not more than 70C higher

than the receiving river water temperature

[Source: OTPC monthly Environmental Monitoring Report, April 2017] Sewage Treatment Plant (STP) Existing Sewage Treatment plant will also cater the requirement of proposed Expansion Project. The sewage treatment scheme includes aerobic biological extended aeration treatment. Aerobic biological sludge generated to be thickened in the Hopper Bottom Clarifier and aerobically digested/dried in a Sludge Drying Bed. The dry sludge shall be disposed manually. The treatment scheme comprises of following parts:

i. Pre-Treatment, which consists of raw sewage collection and pumping, ii. Biological Treatment comprising of aeration followed by clarification

and chlorination, and iii. Sludge Digestion/ Disposal comprising of aeration of excess biological

sludge, and sludge disposal through Sludge Drying Beds. Schematic diagram of STP is presented in


50

Figure 2.20. The characteristics of treated effluent is presented in Table 2.12.

Table 2.12 Characteristics of Treated sewage

Sl. No. Parameter Observed Value Discharge Standard 1. pH 5.5-8.5 5.5 – 9.0 2 TSS (mg/l) 50 100 3. TDS (ppm) 544 - 4. BOD (mg/l) 30 30 5 COD (mg/l) 250 250 6 Faecal Coliform <1000 - 7 Residual Chlorine 0.5 1.0

[Source: OTPC]


51

Figure 2.20 Schematic Diagram of STP


52

2.9.4 Solid and Hazardous Waste

Solid Waste

Solid waste during the construction and operation phases is expected to comprise of food waste and recyclables viz. packaging material, etc. Such waste will be disposed at within the site and recyclable materials will be sold to local waste recyclers. Hazardous Waste

Hazardous waste in the form of used oil and oily cotton waste will be generated. The disposal method is given in Table 2.13.

Table 2.13 Hazardous and E-waste Waste Generation, Storage and Disposal

Sl. No.

Type of Waste Generation Method of Collection Treatment/ Disposal

1. Used/ spent oil 9100 kg/ year This oil is collected in drums and drum stored in an earmarked Hazardous Waste Storage Area

Disposal by sent to registered recyclers.

2. Contaminated cotton rags or other cleaning materials

- Stored in HDPE drums in the earmarked Hazardous Waste Storage Area

3. Spent Resin - Stored in HDPE drums in the earmarked Hazardous Waste Storage Area

2.9.5 Monitoring System

The existing plant has monitoring system for pollution (emission and discharge) from plant to assess the compliance condition given in EC, CTO and other permits. A well-defined environmental monitoring program would be instituted with trained and qualified staff that would monitor the environmental parameters to ensure that the quality emission and discharge is maintained within the permissible levels.

Table 2.14 Environmental Monitoring System for Existing plant and Expansion project

Environmental Component

Monitoring system of existing Plant

Monitoring system for proposed Expansion Unit

Stack emission CEMS in stacks of Unit 1 &2; NOx, SO2, CO

CEMS in stacks of Unit 3 & 4; NOx, PM, SO2, CO

Ambient Air quality

HVS - 4 locations within the plant premises; Twice a week PM10, NOx, SO

HVS - 4 locations within the plant and 4 other location in the AOI; Twice a week; PM10, PM2.5, NOx, SO2, CO

Workplace Noise level

Noise meter: major noise generation sources; Once in every month Noise pressure level

Noise meter: major noise generation sources; Once in every month Noise pressure level


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Environmental Component

Monitoring system of existing Plant

Monitoring system for proposed Expansion Unit

Ambient noise level

Four locations within the plant; Once in every quarter Day time and night time noise level

Four locations within the plant; and 4 location in nearby villages Once in every quarter Day time and night time noise level

ETP treated effluent

Online monitoring system; pH, Temp. TSS

Online monitoring system forpH, Temp, TSS; monthly one grab sample for Free available chlorine, Oil & Grease, Cu, Fe, Zn, Cr, Phosphate

STP treated water

pH, DO, COD, BOD, TDS Online monitoring system pH, DO, COD, BOD, TDS

Surface water quality

Grab samples: 2 locations –upstream & downstream of water intake and discharge point. Once in every quarter Parameters as per CPCB Use-class

Ground water quality

Grab samples: 4 locations in nearby villages Once in every quarter Ground water quality as per IS:10500

Water level in Gumti River

Gumti River: near OTPC water intake facility; Daily Water level

Gumti River: near OTPC water intake facility; Daily Water level

Ground water level

4 monitoring wells around the plant

4 monitoring wells around the plant Monthly Water table

[Source: OTPC] Environmental Monitoring Data

Ambient Air Quality OTPC has four ambient air quality monitoring stations within the plan premises. OTPC has been monitoring ambient air quality twice a week through the year and has been submitting monthly monitoring result has been submitted TSPCB. The month wise average ambient air quality monitoring results for 2016-17 is provided in Table 2.15.

Table 2.15 Air Quality Monitoring Results, carried out by OTPC for EC compliance

Month AAQ-1 (Fire Station)

AAQ-2 (Watch tower behind Switchyard)

AAQ-3 (Gate No. 2) AAQ-4 (Watch tower Trainee Hostel)

Conc. in g/m3 Conc. in g/m3 Conc. in g/m3 Conc. in g/m3 PM10 SO2 NOx PM10 SO2 NOx PM10 SO2 NOx PM10 SO2 NOx

Apr, 16 30.27 1.18 4.6 27.33 2.18 6.64 25.12 1.34 4.78 22.45 1.84 6.84 May, 16 50.0 2.9 4.8 42.0 3.1 5.3 38.0 2.8 5.0 40.0 3.4 6.0 June, 16 30.0 3.5 5.6 28.75 3.5 5.6 26.55 3.2 5.3 29.25 3.6 5.8 July, 16 15.0 3.6 3.5 16.0 3.6 3.2 23.0 3.2 4.5 20.0 4.5 4.8 Aug, 16 20.0 3.8 2.6 22.0 3.7 3.5 25.0 3.2 2.8 30.0 3.9 3.4 Sep, 16 28.36 3.2 3.8 25.24 2.9 2.6 24.11 2.4 3.1 21.88 3.2 2.8


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Month AAQ-1 (Fire Station)

AAQ-2 (Watch tower behind Switchyard)

AAQ-3 (Gate No. 2) AAQ-4 (Watch tower Trainee Hostel)

Conc. in g/m3 Conc. in g/m3 Conc. in g/m3 Conc. in g/m3 PM10 SO2 NOx PM10 SO2 NOx PM10 SO2 NOx PM10 SO2 NOx

Oct, 16 30.2 1.1 3.2 28.1 1.6 2.8 25.6 1.5 2.6 23.9 1.3 3.1 Nov 16 42.5 1.9 3.7 37.2 2.6 1.0 38.2 1.4 3.2 41.0 1.5 3.6 Dec, 16 48.06 2.16 1.0 37.6 1.98 0.8 46.14 1.02 0.88 46.0 2.14 1.0 Jan, 17 54.0 1.42 1.2 64.0 1.52 1.1 38.0 1.48 1.32 36.0 1.19 1.02 Feb, 17 41.5 1.755 0.9 43 1.406 0.928 44.0 1.4 0.9 40.3 1.5 0.9 Mar, 17 44.0 1.30 1.0 47.0 1.80 1.06 46.0 1.90 1.10 44.0 1.70 1.0

[Source: OTPC]

2.9.6 Greenbelt Plantation

The total area demarcated for greenbelt plantation within the plant is approximately 69 acres; i.e. 33% of the total area. Plantation is completed in 69 acres area. Tripura Forest Dept has been carried out 37.08 acres greenbelt plantation and balance 32 ha greenbelt plantation has beendevelioped by OTPC. Species present with numbers is presented in Table 2.16.


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Figure 2.21 Greenbelt Plantation Area


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Table 2.16 Greenbelt Plantation at Site

Year No of Sapling Planted

Area Under Plantation (Acre)

Survival Rate (%)

2013-14 13,400 25.66 89.55 2014-15 10,000 16.7 86.00 2015-16 870 4.64 83.56 2016-17 10,008 13.12 98.93 2017-18 5750 98.95 Total 40,028 69.00 91.40

[Source: OTPC]

Figure 2.22 The Snapshot of Existing Greenbelt

Greenbelt along the eastern side plant boundary

Greenbelt along the western side plant boundary

Landscaping area besides Raw water reservoir Greenbelt plantation: southern side

Greenbelt: eastern side Greenbelt: northern side


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2.10 PROJECT COST

The cost for development of the proposed expansion unit at OTPC- Palatana expansion project is estimated to be about INR 35800 million. The detailed breakup of the proposed cost is presented at the table below.

Table 2.17 Breakup of Project Cost

S No. Cost Head Amount (Rs. in Millions) 1 Land and site development 30 2 EPC Cost 28180 3 Overheads, Pre-Operative Expenses &

commissioning expenses 2170

4 Financial charges 250 5 margin money for WC 1310 6 IDC 3860 Total Capital Cost 35800

[Source: OTPC]

2.11 PRESENT STATUS OF COMPLIANCE

Environmental Clearance

Environmental Clearance (EC) for the project (3X360.8 MW) accorded by MoEFCC vide Letter No. J 13011/11/2006-IA.II (T) dated 07.02.2007. Vide Letter No. J 13011/11/2006-IA.II (T) dated 03.05.2012 validity of EC was extended till 05.02.2017 and plant capacity was increased to 1090 MW (3X363.3 MW). The environmental clearance letter and validity extension letter area attached in Annex 2.6. OTPC commissioned 726.6 MW (2X363.3 MW) Combined Cycle Gas Turbine (CCGT) power project at Palatana, in Tripura. 1st Unit (363.3 MW) was declared under Commercial Operation on 04.01.2014. 2nd Unit (363.3 MW) was declared under Commercial Operation on 24.03.2015. EC Compliance Report

OTPC carries out the periodical environment compliance monitoring (6 monthly) and compliance reports are submitted to Regional office of MoEFCC. The latest RO-MoEFCC certified EC Compliance report (Ref. RO-NE/E/IA/TR/CCGTP/92768 dated 20.11.2017) is provided in Annex 2.7. As per EC compliance report all the EC contions are being complied. The following observations/ recommendation has been proposed by R.O., MoEF&CC:

EC Reference RO observation EC condition No. X: regular monitoring of air quality, including HC levels both in work zone and ambient air

OTPC should carry out regular monitoring of PM2.5 and HC in the ambient air and submit the data to the Regional Office;

EC conditi No. XVI: Regular mock drills for the onsite emergency plan shall be carried out as per the manufacture, Storage and Import of Hazardous Chemical Rules, 3 1989

The project has been requested to provide a copy of proceedings of the mock drill as well as copy of Public Liability Insurance Policy to the regional office.


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EC Condition No. XXII: Separate funds shall be allocated for implementation of environmental protection measures along with them break up.

The information on funds allocated and item wise expenditure made for previous year and for the current year needs to be submitted by the project to the Regional Office

Consent to Operate (CTO)

The plant has a Consent to Operate (CTO) dated 5th August 2017 from TSPCB which is valid till 4th August 2018. OTPC has submitted the renewal application to TSPCB on 26.06.2018. The latest CTO Compliance report is provided in Annex 2.8. Hazardous Waste Authorization

The plant has received hazardous waste authorization from TSPCB vide letter dated 9th March 2016, which is valid till 8th March 2021 (Annex 2.9).


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3 ENVIRONMENTAL BASELINE STUDY

3.1 INTRODUCTION

This chapter describes the existing environmental settings of the study area which include the project site and area within 10 km radius from the boundary of the project site. This study includes the physical environment, biological environment and socio-economic environment. The purposes of describing the environmental settings of the study area are:

To understand the project needs and environmental & social characteristics of the area; and To assess the existing environmental quality, as well as the environmental impacts of the future developments being studied.

Study Area

The study area has been delineated on the basis of the approved ToR by EAC, MoEFCC. The study area comprises of 10 km radius from the OTPC-Palatana plant. The study area along with project location is shown in Figure 3.1 Study Period

The primary baseline environment study was undertaken for pre-monsoon season from March 2017 to May 2017. Approach and Methodology

The baseline data is collected through primary and secondary source of information with reference to the approved ToR. This data is collected through a concerted effort of:

Reconnaissance and field visits; Primary monitoring of key environmental parameters like air, water, soil, noise, traffic. The primary monitoring was conducted by Mitra SK Private Limited [a NABL accredited laboratory]; Information about geology, hydrology, prevailing natural hazards like floods, earthquakes etc. have been collected from literature reviews and authenticated information made available by government departments. Surveys were carried out to understand and record the biological environment prevailing in the area and the same was verified against published information and literature. The socioeconomic environment has been studied through consultations with various stakeholders in the villages within the study area. Additionally, socioeconomic data have been obtained from the Census of India reports.


60

Figure 3.1 Study Area Map


61

3.2 PHYSICAL ENVIRONMENT

3.2.1 Land Environment

Topography

In Tripura, the major geomorphic features observed are “highs” and “depressions”, “flats” and “slopes “, sculptured on the topographic surface in a linear array and areal spread. The highs and lows correspond with the normal first order structural elements. The study area also shows elevated ridges represented by the natural forest areas and rubber plantations with flat areas represented by the river valleys (particularly of Gumti River) and agricultural lands. The elevation of the study area varies between <32 m at the central portion of the study area on either side of Gumti River to about 62 m and higher at the outer edges of the study area.. The study area has a natural slope from northeast to west and southwest. Topography map of the study area is presented in Figure 3.2. Geology

The state of Tripura is characteristically underlain by a wide range of sedimentary rocks that has origin in marine-mixed fluvial type. The age ranges from upper most Oligocene (38 million years from present times) to recent period. As per Geological Survey of India (GSI), the sediments have been laid down in the Surma basin during tertiary age (which lasted for 65 million years) in a wide range of environmental conditions primarily governed by tectonic movement. Tectonically, the region now comprises a series of sub-parallel arquate, elongated doubly plunging folds arranged in north-south direction. The anticline folds are separated by wide flat synclines.1 Mineral Resources

Natural gas is the most important mineral resource in Tripura located in the Assam Arakan Fold Belt (AAFB) basin. Other minerals of significance found to occur in the State are glass sands, limestone, fireclay, plastic clay, shale and quartz-silica sand used particularly for building/construction purposes. The OTPC project site is located in Sundulbari-Agartala Dome PML Block. The mineralogical map is presented in Figure 3.3.

1 http://www.nidm.gov.in/pdf/dp/Tripura.pdf


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Figure 3.2 DEM Map of the Study Area


63

Figure 3.3 Project Site on Mineralogical Map

[Source: Map_Tripura_State_Geology_and_Mineral_Map_Geological_Survey_of_India]


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Land Use and Land Cover

The land use and cover of the project site and its surrounding area have been studied using Landsat 8 Imagery dated 27.02.2017 and subsequently ground truthing during the field surveys. Land Use and Land Cover in the Project Site The total project site area is 197.15 acres. Presently project is utilizing 164.05 acre of land. The proposed expansion would involve utilization of additional 33.1 acre area within the plant. The land use details of the plant is provided in Section 2.4. Land use- land cover in the Study Area The predominant land use-land cover of the study area includes rubber plantation (37.72%), agricultural land (27.48%), settlement & homestead plantation (22.75%), natural forest (10.36%), river (0.86%), waterbody (0.25%), etc. The land use of the study area is presented in Table 3.1 and Figure 3.4.

Table 3.1 Land Use and Land Cover in Study Area

Land Use Type Area (sq. km) Percentage Agricultural Land 86.31 27.48 Canal 0.28 0.09 Forest 32.54 10.36 Industry 0.77 0.25 Plantation 118.46 37.72 Rail 0.14 0.05 River 2.69 0.86 Road 0.62 0.20 Settlement with Homestead Plantation 71.46 22.75 Waterbody 0.79 0.25 Total 314.06 100.00

[Source: Derived from ESRI World Imagery]


65

Figure 3.4 Land Use and Land Cover Map of the Study Area


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Soil Quality

The soil types of Tripura can be classified under five major groups; these are red loam, sandy loam reddish yellow brown sandy soils, older alluvial soils and younger alluvial soils. The soils in the study area is mostly sandy loam type. Soil Monitoring Locations

Soil was monitored at five (5) locations within the study area. Three locations were selected from agricultural lands and one location was selected from forest area and one sample was taken from the Green belt area within the project site. Soil sampling location is shown in Figure 3.6 and Table 3.2. Primary soil monitoring also includes analysis of the heavy metals with the objective of establishing baseline values for such contaminants (if present in the soil).

Table 3.2 Soil Sampling Locations in the Study Area

Location Code

Location Land Use Type

Geographical Location

Selection Criteria

S-1 Dudhpuskarini village

Forest 23°30'14.30"N 91°26'51.90"E

Understand the existing soil quality and assess impacts on soil quality due to operation of plant (emission and surface runoff).

S-2 Palatana village Agricultural land

23°30'56.10"N 91°25'43.70"E

Understand the existing soil quality and assess impacts on soil quality due to operation of water intake facility.

S-3 Kushamara village

Agricultural land

23°29'35.40"N 91°26'4.30"E

Understand the existing soil quality and assess impacts on soil quality due to operation of the plant (emission and surface runoff)..

S-4 Jamjuri village Agricultural land

23°31'11.20"N 91°28'22.80"E

Understand the existing soil quality and assess impacts on soil quality due to construction of OTPC residential unit.

S-5 Greenbelt area of OTPC Plant

Greenbelt area

23°29'19.80"N 91°26'17.30"E

Understand the existing soil quality and assess impacts on soil quality due to surface runoff and operation of ETP & STP


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Figure 3.5 Photographs of Soil Sample Collection

Soil sampling at Dudhpuskarini village Soil sampling at Palatana village

Interpretation of soil monitoring results

Agricultural soils (S2, S3,S4) pH: The pH level in soil samples varies in between 4.8 to 6.15 indicating presence of strongly to slightly acidic soils as per standard soil classification.

Texture: The texture of soil samples was found to be clay and sandy clay in nature. EC: The values ranged between 37.8 micro Siemens/cm and 91.2 micro Siemens/cm. Organic carbon: Organic carbon contents varied between 0.36-0.6 mg/kg. Nitrogen content: The available nitrogen content varied between 134 to 268 mg/kg. Phosphorus content: The available phosphorus content ranged between <3 to 6.5 mg/kg. Potassium content: The available potassium content ranged between 30 to 40 mg/kg. Sodium Absorption Ratio (SAR): The SAR values in the soil samples collected from agricultural lands were ranged from 0.06 to 0.10. Heavy Metals: The levels of iron level in the agricultural land soil samples ranged between 61 mg/kg to 280 mg/kg, copper ranged between 4.4 mg/kg to 14.0 mg/kg, lead was ranged between 5.2 mg/kg to 10.0 mg/kg; and chromium level was ranged between 10 mg/ to 22 mg/kg. Cadmium content of the samples was less than 2 mg/l.


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Figure 3.6 Primary Monitoring Location Map for Soil, Surface Water & Ground Water


69

Forest and Greenbelt Soil

pH: The values observed was 4.9 and 5.05 Texture: The texture of soil samples was clayey in nature. EC Values: The EC value was 35.0 -50.2 micro Siemens/cm. Sodium Absorption Ratio: The SAR ran 0.16 and 0.09. Organic carbon: Organic carbon contents were 0.60 and 0.46 mg/kg. Nitrogen content: The available nitrogen contents were 235.0 and 202 mg/kg. Heavy metals: Iron was found in samples in the range of 28-69 mg/kg; concentration of copper was 5.4mg/kg and 11 mg/kg respectively; lead was ranged between 6.2 mg/kg to 12.0 mg/kg; and chromium level was ranged between 17 mg/ to 29 mg/kg. Cadmium content of the samples was less than 2 mg/l.

In general soil in the study area was found to be acidic in nature and poor in nutrient content. However, the soil does not indicate presence of heavy metal contamination. Soil Quality results is presented in Table 3.3.

Table 3.3 Soil Quality Monitoring Results

Sl. No.

Parameters Unit Sampling Location S-1 S-2 S-3 S-4 S-5

1 pH (1:2.5) at 25 deg c None 4.9 6.15 5.38 4.8 5.05

2 Calcium (as Ca) mg/kg 200 1500 1200 400 600 3 Copper (as Cu) mg/kg 5.4 14 4.4 6.2 11 4 Iron (as Fe) mg/kg 69 280 245 61 28

5 Magnesium (as Mg) mg/kg 60 60 120 180 240

6 Cadmium (as Cd) mg/kg <2 <2 <2 <2 <2

7 Lead (as Pb ) mg/kg 6.2 10 5.2 8.4 12 8 Arsenic( as As) mg/kg <0.25 <0.25 <0.25 <0.25 <0.25

9 Texture None Clay Clay Sandy Clay Clay Clay

10 Electrical conductivity μS/cm 35.0 91.2 37.8 39.1 50.2

11 Potassium (as K) mg/kg 50 30 40 30 70

12

Sodium Adsorption Ration (as SAR) None 0.16 0.07 0.06 0.10 0.09

13 Water Holding capacity % 40.4 44.7 34.6 38.9 41.2

14 Cation Exchange Capacity

meq/100 gm 10.3 26.4 24.5 17.8 19.2

15 Phosphorus (as P) mg/kg <3 <3 5.1 6.5 <3

16 Porosity % 49.7 54.3 47.9 50 48.8 17 Nitrogen (as N) mg/kg 235 201 134 268 202 18 Organic Carbon % 0.60 0.53 0,36 0.6 0.46 19 Chromium mg/kg 17 22 10 21 29

[Source: Primary Monitoring 2017]


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3.2.2 Natural Disaster

Tripura is prone to natural hazards such as earthquake, flood and cyclone.

Earthquakes

Tripura lies in Zone V, the most severe seismic zone (as per Bureau of Indian Standards (BIS) 2000). The state experiences moderate to large magnitude earthquakes. As per a report by National Institute of Disaster Management, a major earthquake of magnitude 6.3 Richter occurred within North Tripura district causing damage to the buildings and other infrastructures. A large number of moderate to large magnitude earthquakes have occurred within the State boundary as well as within 100 km distance around it. Major and significant earth quakes have been furnished in Table 3.4.

Table 3.4 Significant Earthquakes in Tripura

Date/ Year

Location of Epicentre

Remarks

1869 within 18 km of the district town of Dharmanagar

An earth quake of M 7.5 occurred, caused massive destruction in permanent infrastructures and lives. The old royal palace at Udaipur got destroyed form this earth quake.

12th June 1897

In Shillong Plateau, near Rangjoli, Assam

An earthquake took place in the state and adjacent areas of which magnitude M 8.7. This was one of the most powerful earthquakes in the Indian sub-continent. The quake wreaked havoc across the present states of Tripura, Assam and Meghalaya.

1918 N.A. Srimangal area experienced an earth quake with a magnitude of M 7.6

1930 Dubri An earth quake took place with a magnitude of M 7.1

15th Aug, 1950

Indo-China Border Region

An earth quake hit mainly the northern part of Tripura and it was originated from Indo-China boarder region. The magnitude of this earth quake was 8.5 Richter. It was the 6th Largest earth quake of 20th century.

1950 N.A. An Earthquake of magnitude 6.3 Richter occurred within North Tripura district caused damage to the buildings and other infrastructures

1970 to 2000

N.A. According to the records of the Indian Meteorological Department, 41 earthquakes of 5.6 or lower magnitude have occurred within the coordinates 23.00º-25.00ºN and 91.00º-93.00ºE

2013 In the state of Mizoram

little tremor felt in the southern part of the state and the epicenter of which was located at Mizoram

Source: 1. Tripura Disaster Management Authority, Tripura India http://tdma.nic.in/V_EARTHQUACK.htm Flood

In Tripura flooding of river during monsoon and flash floods in hill areas is commonly experienced. The flooding in the low lying lands is mainly due to siltation due to continued erosion of land. The major floods recorded in the state are summarized below:


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Table 3.5 Major floods in the state of Tripura1

Sl No Year Region Extent of Damage 1. 1983 Entire state Lives lost; huge no. of houses damaged,

crops lost 2. 1993 North Tripura and Dhalai House and crop damaged 3. 1998 South Tripura and West

Tripura 7 lives lost; 11516 houses damaged; public infrastructures severely damaged

4. 1999 South Tripura and West Tripura

16 lives lost; 4014 houses damaged; other properties lost: Rs.50 Crore

3.2.3 Air Environment

Climate & Meteorology

The climate of the Gomati District is mostly warm, characterized by humid summer and dry winter. Rainfall is received from the South -West Monsoon, which normally arrives in the month end of May or starting of June. Rainfall primarily occurs during June to September. The study area falls under the humid sub-tropical climate zone with warm seasons. Seasons

There are four well defined seasons that has been shown below: Pre-monsoon : March-May Monsoon : June- September Post-monsoon : October- November Winter : December- February

The meteorological data of IMD station at Agartala has been used for interpretation of temperature profile, rainfall pattern, relative humidity, wind speed and wind direction in the study area. Temperature

The mean monthly maximum and mean monthly minimum recorded over a period of 1961 to 1990 shows that mean monthly maximum temperature is experienced in April (33.5°C) and the mean monthly minimum temperature is experienced in January (9.9°C). The variation in daily temperature is observed to be maximum in January (a difference of 15°C).

1 http://www.tdma.in/History_Of_Earthquake.htm


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Figure 3.7 Mean Monthly Maximum and Minimum Temperature recorded at Agartala

Source: IMD

Rainfall

Average annual rainfall in the Gomati district is about 2000 mm1. The average rainfall data for Gomati district for the year 2007-11 reveal total annual rainfall of 2058 mm. January-March and November-December received very little rainfall. Rainfall was highest in June (416.7 mm), followed by August (345.1mm), and July (300.9 mm). The average monthly variation of rainfall during 2007 to 2011 is presented in Figure 3.8.

Figure 3.8 Rainfall in Gomati District (2007-11)

Source: http://gomati.nic.in/

1 http://gomati.nic.in/


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Wind Speed and Direction

The annual daily surface wind recorded from 1971 to 2000 for Agartala IMD Station shows that 26% of the years the winds are from the South followed by South-East (18%). The maximum wind speed is greater than 7m/s. Calm has been observed for 28% of the time. The average wind speed was observed to be between 1.5-4.5m/s. The annual windrose diagram is presented in Figure 3.9.

Figure 3.9 Annual Wind Speed and Wind Direction (1971-2000) for Agartala

Source: IMD Site Specific Meteorology

Site-specific micro-meteorological data has been collected for the study period (from March to May 2017), using an automatic weather monitoring station. The automatic weather monitoring station was installed at the rooftop of the fire station building of the OTPC plant at a height of about 10 m above the ground level, ensuring that there were no obstructions to the free flow of winds. The summary of the recorded data is provided below. Temperature As per the above table, site specific surface temperature varied between 18.1°C to 37.1°C in May. The average temperature during the monitored period was 27.7°C. Relative Humidity The site specific relative humidity varied between 19.0% to 97.9%. The average humidity was 71.71% during the monitored period.


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Wind Speed The wind speed during the monitored period varied from 0.0 km/hr to 27.0 km/hr. The average wind speed during the period was 2.24 km/hr. The predominant wind direction of the study period is from south-east. Windrose diagram of the study area during the period of study is presented in Figure 3.10.

Figure 3.10 Windrose Diagram of Study Period

Source: Primary Survey


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Rainfall Total 31 days with rainfall was received during the study period with total rainfall of 467 mm. The site specific hourly meteorological data is for the study period is provided in Annex 3.1. Ambient Air Quality

The study area resembles a pre-dominantly rural landscape with villages interspersed between agricultural lands, rubber plantations and natural forests. The major emission sources are vehicles, brick kilns and burning of dried crops as part of jhum cultivation. The major sources of emissions due to the proposed project is construction activities, movement of vehicles, operation of boilers, operation of DG sets etc. Primary Air Quality Monitoring

Ambient Air quality was monitored at 8 locations across the study area. The parameters studied were Particulate Matter (PM10 and PM2.5), Oxides of Nitrogen (NOx), Sulfur dioxide (SO2), Carbon Monoxide (CO), Ozone, Hydrocarbon (Methane and Non-methane) and mercury for twice a week for twelve weeks. Air quality monitoring locations were selected based on the following aspects covered in field survey plan developed prior to the field work:

Meteorological conditions of the area based on information of IMD observatory at Agartala; Topography of the study area; and Location of sensitive receptors such as major settlements;

The justification for selection of the monitoring locations is given in Table 3.6. The location of ambient air quality monitoring station is presented in Error! Reference source not found.

Table 3.6 Air Monitoring Locations

Sl No

Location Number

Monitoring location Name

Geo-coordinates

Distance & Direction

Rationale for selection

1. AAQ1 OTPC Plant 23°30'03.5"N 91°26'16.8"E

Within Plant Boundary

Within plant: To understand the existing air quality and assess the potential impact from proposed expansion project

2. AAQ2 Dudhpuskarini village

23°29'40.8"N 91°26'42.8"E

0.35 E Cross wind: To understand the existing air quality

3. AAQ3 Palatana Village

23°30'42.1"N 91°26'42.8"E

1.00; N Downwind: To understand the existing air quality and assess the potential impact from proposed expansion project

4. AAQ4 Kakraban 23°29'42.1"N 91°26'31.6"E

2.00; W Up wind: To understand the existing air quality

5. AAQ5 Matabari 23°31' 02.2"N 91°30'13.9"E

6.50; E Cross wind: To understand the existing air quality


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Sl No

Location Number

Monitoring location Name

Geo-coordinates

Distance & Direction

Rationale for selection

6. AAQ6 Uttar Shilghati village

23°31' 03.0"N 91°24'04.4"E

3.80; NW Downwind: To understand the existing air quality and assess the potential impact from proposed expansion project

7. AAQ7 Topani Village 23°32' 22.5" N 91°27'46.5"E

4.70; NE Downwind: To understand the existing air quality and assess the potential impact from proposed expansion

8. AAQ8 Gangachhara Village

23°27'48.1"N 91°27'67.4"E

3.30; S Upwind: To understand the existing air quality


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Figure 3.11 Monitoring Location Map: Air, Meteorology and Traffic


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Figure 3.12 Photographs of Air Sampling

Air Quality Monitoring location: Kakraban village

Air Quality Monitoring location: within Plant

Metrological Monitoring at Plant site Air Quality Monitoring location: Uttar Silghati

Interpretation of Monitoring Results The monitoring results were compared with the National Ambient Air Quality Standards (NAAQS) and the interpretation is discussed in the following subsections. The summary of ambient air quality monitoring results is presented in Table 3.7. Detailed monitoring results are provided in Annex 3.2. Particulate Matter (PM10) The average PM10 concentration in the monitoring locations during the study period ranged from 55.33 g/m3 to 66.08 g/m3. Lowest average concentration was recorded at Dudhpuskarini village while the highest average concentration was recorded at OTPC plant. The higher concentration of PM was recorded may be due to construction work on adjacent Kakraban-Udaipur Road as well as construction work within the plant. The 98th percentile concentration in the monitoring locations was varied from 69.08 g/m3 to 94.32 g/m3. The average and 98th percentile PM10 values were observed to be in compliance to the prescribed NAAQS of 100 g/m3 at all locations. The variation of PM10 are shown below in Figure 3.13.


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Figure 3.13 Concentration of Particulate Matter (PM10) in Study Area

Source: Primary Monitoring Particulate Matter (PM2.5) The average PM2.5 concentration in the monitoring locations during the study period ranged from 26.04 g/m3 to 32.13 g/m3. Lowest average concentration was recorded at Tapani village while the highest average concentration was recorded at OTPC plant. The 98th percentile concentration in the monitoring locations was varied from 37.08 g/m3 to 47.7 g/m3. The average and 98th percentile PM2.5 values were observed to be in compliance to the prescribed NAAQS of 60 g/m3 at all locations. The variation of PM 2.5 are shown below in Figure 3.14.

Figure 3.14 Concentration of Particulate Matter (PM2.5) in Study Area

Source: Primary Monitoring


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Sulphur Dioxide (SO2) The average SO2 concentration in the monitoring locations during the study period ranged from 5.03 g/m3 to 5.82 g/m3. The 98th percentile concentration in the monitoring locations varied between from 6.41 g/m3 to 7.92 g/m3. The average and 98th percentile SO2 values were observed to be in compliance to the prescribed NAAQS of 80 g/m3 at all locations. The variation of SO2 are shown below in Figure 3.15.

Figure 3.15 Concentration of SO2 in Study Area

Source: Primary Monitoring Nitrogen Di-oxide (NO2) Average NO2 concentration ranged between 21.01 μg/m3 and 24.13 μg/m3 and 98th percentile ranged between 27.09μg/m3 and 31.97 μg/m3. The 98th percentile NO2 values were observed well within the prescribed 24-hourly NAAQS of 80 g/m3 at all locations. The concentrations of NO2 are shown in Figure 3.16.


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Figure 3.16 Concentration of NO2 in Study Area

Source: Primary Monitoring Carbon Monoxide (CO) The average CO concentrations ranged between 0.32 mg/m3 and 0.45 mg/m3 and 98th percentile values ranged between 0.45 mg/m3 to 0.79 mg/m3. The 98th percentile CO values at all the stations were in compliance to the NAAQS value of 2 mg/m3. Variation in CO concentrations is shown in Figure 3.17.

Figure 3.17 Concentration of CO in Study Area

Source: Primary Monitoring Ozone (O3) Maximum concentration of ozone at the monitoring locations varied between 21.20 g/m3 to 31.20 g/m3 while the minimum concentrations were <10

g/m3 at all the stations. Maximum concentrations of ozone at the monitoring locations were in compliance to the 8 hourly NAAQS value of 100 g/m3.


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Hydrocarbon Average hydrocarbon concentration ranged between 1.21ppm and 1.80ppm and 98th percentile ranged between 1.74 ppm and 2.61 ppm. There is no NAAQS specified value for hydrocarbon concentration in ambient air. Mercury Mercury concertation at all the monitoring locations were found to be <0.04 ng/m3. There is no NAAQS specified value for mercury concentration in ambient air. Summary of ambient air quality monitoring data is presented at the Table 3.7 below. Details of monitoring results are presented in Annex 3.2

Table 3.7 Summary of Ambient Air Quality Monitoring Results

AQ1 AQ2 AQ3 AQ4 AQ5 AQ6 AQ7 AQ8

PM10 in g/m3 Max 98.00 75.00 82.00 74.00 70.00 78.00 73.00 75.00 Min 31.00 30.00 43.00 28.00 34.00 41.00 42.00 38.00 Average 66.08 55.33 61.08 56.96 55.96 59.17 55.38 56.50 98th percentile 94.32 74.08 78.78 73.54 69.08 76.62 71.62 70.86 NAAQS 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00

PM2.5 in g/m3 Max 44.00 48.00 50.00 44.00 38.00 42.00 42.00 40.00 Min 13.00 15.00 21.00 15.00 18.00 16.00 17.00 18.00 Average 31.33 27.29 32.13 28.21 27.42 28.96 26.04 28.00 98th percentile 44.00 46.62 47.70 43.08 37.08 41.08 37.86 39.08 NAAQS 60.00 60.00 60.00 60.00 60.00 60.00 60.00 60.00

SO2 in g/m3 Max 8.20 6.90 7.20 6.70 6.70 6.60 6.50 8.20 Min 4.00 4.00 4.20 4.00 4.20 4.10 4.00 4.00 Average 5.78 5.28 5.57 5.22 5.25 5.03 5.06 5.82 98th percentile 7.88 6.85 7.20 6.61 6.70 6.42 6.41 7.92 NAAQS 80.00 80.00 80.00 80.00 80.00 80.00 80.00 80.00

NO2 in g/m3 Max 30.50 28.50 32.20 27.60 28.50 32.20 30.40 31.20 Min 13.60 12.50 16.60 15.60 16.60 15.30 12.20 15.50 Average 24.13 21.01 22.57 21.65 22.06 21.51 21.19 22.06 98th percentile 30.45 28.18 31.97 27.09 28.09 31.74 28.93 30.05 NAAQS 80.00 80.00 80.00 80.00 80.00 80.00 80.00 80.00

CO in g/m3 Max 0.72 0.78 0.79 0.65 0.48 0.65 0.47 0.74 Min 0.25 0.21 0.21 0.18 0.21 0.25 0.23 0.21 Average 0.45 0.39 0.36 0.39 0.35 0.44 0.32 0.35 98th percentile 0.69 0.69 0.70 0.62 0.48 0.61 0.45 0.70 NAAQS 2.00 2.00 2.00 2.00 2.00 2.00 2.00 2.00

Ozone in g/m3 Max 31.20 21.20 26.50 21.50 26.60 27.50 23.50 30.20 Min <10.0 <10.0 <10.0 <10.0 <10.0 <10.0 <10.0 <10.0 Average - - - - - - - -


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AQ1 AQ2 AQ3 AQ4 AQ5 AQ6 AQ7 AQ8 98th percentile - - - - - - - - NAAQS 100 100 100 100 100 100 100 100 Hydrocarbon in ppm Max 1.81 1.74 1.85 1.78 2.66 2.66 2.65 1.89 Min 0.76 0.85 0.70 0.85 0.98 1.02 1.03 0.77 Average 1.25 1.26 1.21 1.25 1.64 1.80 1.73 1.26 98th percentile 1.79 1.74 1.79 1.74 2.49 2.61 2.60 1.88 NAAQS - - - - - - - - Mercury in ng/m3 Max <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 Min - - - - - - - - Average - - - - - - - - 98th percentile - - - - - - - - NAAQS - - - - - - - -


3.2.4 Ambient Noise Quality

The ambient noise level at the project area resembles that of a rural landscape with occasional plying of public transport vehicles like, two wheelers, tractors, trekkers and cars at the internal village roads. Sampling Methodology

Ambient noise was monitored at 8 locations. The villages close to the plant site were given preference for monitoring locations. The 24-hour baseline noise monitoring was conducted by using the portable sound meter (Lutron, SL-0423SD, unit: dB(A)). Noise level (LAeq) were measured and recorded at a ten-minute interval and averaged at an hourly and daily (i.e. 24-hour) interval using the following formula: LAeq = 10*Log 10(Average (10^ ((X)/10))) where X is measured noise in dB(A).

Table 3.8 Noise Monitoring Locations

Stn. Code

Sampling location

Category of Area/ Receptor

Geo-coordinates

Selection Criteria

NQ1 Khilpara Residential 23°31'31.0"N 91°28'12.6"E

Baseline noise level and assess the potential impact from cooling tower.

NQ2 Dudh Puskurani -2

Residential 23°29'35.7"N 91°26'3.2"E

Baseline noise level and assess the potential impact from power plant and raw water pump house.

NQ3 Kakraban Residential 23°29'19.2"N 91°23'9.9"E

Baseline noise level and assess the potential impact from plant.

NQ4 Dudh Puskurani -1

Residential 23°29'40.5"N 91°26'43.1"E

Baseline noise level and assess the potential impact from plant and traffic.


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Stn. Code

Sampling location

Category of Area/ Receptor

Geo-coordinates

Selection Criteria

NQ5 OTPC Plant Roof Top Medical Centre

Industrial 23°30'2.7"N 91°20'19.9"E


NQ6 Palatana Residential 23°30'25.5"N 91°25'40.6"E


NQ7 Mogpuskarani bridge

Residential 23°28'43.2"N 91°26'40.9"E

Baseline noise level.

NQ8 Amtali Residential 23°30'55.1"N 91°25'37.2"E

Baseline noise level.

Noise Monitoring Results

The daytime equivalent noise levels observed at different residential areas ranged between 42.0-53.8 dB(A) in the study area and the night time equivalent noise levels ranged between 37.6-43.7 dB(A). These noise levels were in compliance to the CPCB day time and night time noise standards [55dB(A) and 45 dB(A) respectively] for residential areas. The daytime and night time equivalent noise levels were found to be 66 dB(A) and 53.1 dB(A) respectively for the noise monitoring location within the OTPC plant areawhich is in compliance to the CPCB day time and night time noise standards [75dB(A) and 70 dB(A) respectively] for industrial areas. The equivalent day time and night time noise levels in comparison to the respective CPCB standards are presented in Table 3.9 and Figure 3.18. The hourly noise quality monitoring results is presented in Annex-3.3.

Table 3.9 Ambient Noise Quality in the Study Area

Stn Code

Sampling Location Leq Day (dBA)

Leq Night (dBA)

CPCB Limits Leq (dBA) Day Night

NQ1 Khilpara 53.8 43.7 55 45 NQ2 Dudh Puskurani -2 42.0 38.6 55 45 NQ3 Kakraban 43.7 38.9 55 45 NQ4 Dudh Puskurani -1 42.4 37.6 55 45 NQ5 OTPC Plant Roof Top Medical

Centre 66.0 53.1 75 70

NQ6 Palatana 41. 7 38.9 55 45 NQ7 Mogpuskarani bridge 41.8 38.5 55 45 NQ8 Amtali 42.5 38.4 55 45



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Figure 3.18 Noise Monitoring Results


3.2.5 Traffic and Transport

The site can be approached from NH-44 from Agartala till Udaipur and from Udaipur via. Udaipur- Kakraban Road. One traffic monitoring station was selected on Udaipur- Kakraban Road (Figure 3.11) near the OTPC project main gate. At this location the traffic survey was conducted continuously for 24 hours, one time during the study period. The traffic survey was done for both way movement of vehicles and categorized as heavy motor vehicles (truck, bus, dumper, tanker and trailer), light motor vehicle (car, jeep, van, matador, tractor, tempo and mini bus), two/three wheelers (scooter, motor cycle, auto, moped) and non-motorized vehicles (bicycle, tricycle). Summary of traffic observed in the study area is given in Table 3.10. Hourly Traffic monitoring data is presented in Annex 3.4.

Table 3.10 Traffic Values observed in the Project study area

Description Traffic Volume Heavy Motor Vehicles 618 Light Motor Vehicle 2186 Two/Three Wheelers 2589 Non-motorized Vehicles 145 Total PCU (Nos.)/24 Hours (To & From) 5673 Average PCU Flow/Hr 236 Max PCU (Nos)/Hr 392 Min PCU (Nos)/Hr 78 Minimum PCU Hours 09.00-to 10.00 hrs Maximum PCU Hours 02.00-03.00 hrs

Source: Primary Monitoring, 2017 Interpretation of Traffic Survey Results Total 5673 PCU was recorded at the traffic monitoring station. As per observation made for traffic density, on an average 236 PCU was recorded at


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this location. It was also noticed that major contributor (47%) of the vehicular traffic was two/three wheelers followed by Light motor vehicles (39%). Heavy vehicles (Truck, Bus, Dumper, Tanker and Trailer), contributed 11% of the total density while contribution of non-motorizes vehicle like bicycle, tricycle etc. towards total vehicular traffic was fewer. Figure 3.19 illustrates contribution of different type of vehicle towards total vehicular traffic at the monitored station. At this location maximum traffic was observed to be 392 PCU between 09:00 to 10:00 hrs, while minimum traffic observed was 78 PCU between 02:00 to 03:00 hrs.

Figure 3.19 Contribution of Different Type of Vehicle at Udaipur-Kakraban Road

Source: Primary Monitoring, 2017

3.2.6 Water Environment

Drainage pattern

The drainage pattern of Tripura are of ‘dendritic’, ‘parallel’ to ‘sub-parallel’ and ‘rectangular’ types. The stream channel patterns lie mainly within the piedmont, straight and meandering reaches. The study area falls within the watershed of Gumti River1. Gumti River flows northeast to south west within the study area at a nearest distance of 2 km north of the site. Drainage pattern within the study area is dendritic in nature. There is also a drainage channel at the north of the Gumti River and parallel to it. Drainage map of the study area is presented in Figure 3.20.

1 The river Gumai rises from the range connecting Longtharai and Atharamura. The total length of the river from origin to Indo-Bangladesh border is 167.4 km. At the source Raimacherra flows from the confluence of Kalyansingh and Malyansingh near Kanti Charan Para in the eastern part of Amarpur subdivision till it meets the Surmanadi near Duchaibari at the altitude of 86.87 m. After this point the river assumed the name of Gumti and flows down through deep gorges upto Dumbur falls. The Gumti takes a westerly turn at this point and flows down for about 10 km, where it turns northward upto Amarpur and again flows westwards and enters into the plains near Maharani. After entering into the plains the river generally flows in west and south-west direction and it enters into the Bangladesh territory at Sonamura. The river then flows through plains of Bangladesh and meets the Meghna river system.


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Figure 3.20 Drainage map of Study Area


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Surface Water Resource

Hydro-Eecology Study: The existing unit of OTPC is withdrawing 25,320 m3/day water Gomati River. The additional water demand for proposed expansion project is 20400 m3/ day. This additional volume of water will be sourced from existing water intake facility of Gomati River. As per approved ToR, Eco-hydrology study undertaken assessing the impact of proposed water withdrawal from River Gomati on downstream competing users such as agriculture, domestic and other users, biota through an Institute of National Repute. In this regard, Dept. of Civil Engineering, National Institute of Technology (NIT) Agartala was engaged for this study. The findings of the study are discussed in following section. River Basin & Catchment

The Gumti basin is situated in the lower middle part of Tripura. Gumti is the major river of Tripura. The basin lies in the districts of South Tripura, West Tripura and some part of Dhalai; spreading from eastern to western boundary of the state.

The catchment area of river Gumti is 2,492 km2 within Indian Union and it has the largest basin among the rivers of Tripura. 1,921 km2 lies in the hill catchment and only 571 km2, which is nearly 22.9% of the total catchment, lies in the plains. Out of the total catchment area of 2,492 km2, 2,360 km2 lies in Udaipur, Amarpur and Gandachara sub-divisions of Gomati and Dhalai districts and remaining 132 km2 lies in the Sonamura sub-division of the Sepahijala district (Source: The Master Plan of Gumti Sub-Basin, 1996). Drainage

The flow length of the Gumti River in the state is about 167.4 km and has about 2,492 km2 as catchment area. The basin run-off essentially depends on various factors like intensity and duration of rainfall, its distribution, extent of catchments area, vegetal cover and relief and slope among others. The anticlinal hill ranges in Tripura state form watersheds from which various drainage patterns emerge. Each valley is drained by a river to which several perennial and ephemeral streams join and produce dendritic drainage pattern. During the dry season all the important river in the state are fed by ground water and maintain certain base flow. The drainage map of the study area is presented in Figure 3.20. Water Level in Gumti River

The pre-monsoon and monsoon season water level in up-stream and downstream of OTPC intake well was measured on 24th -25th May 2017 and 3rd – 4th August 2017 respectively. Water level monitoring was conducted in 24 locations. The monitoring location is presented in following figure.


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Figure 3.21 Water Level Monitoring Location Map

The upstream and down-stream water level of OTPC intake well is presented in following table.

Table 3.11 Pre-monsoon and Monsoon Water Level

Sl. No.

Location Distance from Intake Well (m)

Width (m)

Max. River bed depth (m)

Max Water Depth (m) Pre-monsoon Monsoon

1. RL-1 (upstream) 850 90 4.27 1.17 2.41 2. RL-4 (upstream) 500 85 4.46 1.22 2.35 3. RL-9 (upstream) 20 80 4.26 1.00 3.60 4. RL-10 (Intake well) 0 80 4.43 1.93 2.40 5. RL-11 (downstream) 10 75 4.12 1.62 2.55 6. RL-13 (downstream) 60 65 3.74 1.14 1.88 7. RL-16 (downstream) 340 95 4.62 1.60 2.50 8. RL-20 (downstream) 900 75 6.86 3.40 3.90 9. RL-22 (downstream) 1670 75 6.02 2.52 3.43 10. RL-24 (downstream) 2550 85 5.83 2.00 3.30

[Source: Primary Survey May 2017 and August 2017] Water Uses

Agriculture: In the study area (along the 10 km river stretch) there are five villages namely Palanata, Kakraban, Silghati, Amtali and Hadra. The people in these villages are engaged in agricultural practice and for this; they are irrigating the crop land by river water through pumps. The estimated surface water used for irrigation is about 515.27 million m3/year. Domestic Use: The people living along the bank of the river Gumti are using the river water for their domestic use like washing clothes, utensils etc. The estimated water demand in the study area is about 6.76 million m3/year.


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Industrail Use: Existing units of OTPC is the only industry in the study area using the water from Gumti River. The current demand is 5.49 million m3. Water lossess

The estimated water losses are as follows: Evaporation loss & Ground Water Flatuation: The estimated evaporation loss and ground water flatuation in the study area is 5.48 million m3.

Table 3.12 Consumption of Water from Gumti River in Study Area

Sl. No.

Water Use Existing Waer Demand (million m3/ year)

Additional Future Water Demand (ater 10 Years) (million m3/ year)

1. Agriculture 515.27 7.81 2. Domestic use 6.76 5.29 3. Water required for plant 7.85 6.32 4. Evaporation loss and Ground water

fluctuation 5.48

Total Water Demand 535.36 19.42 [Source: NIT Hydrology Study Report 2018]

The estimated total discharge of river Gumti in the study area is approximately 1096.32 m3/year. The available water after all uses & losses is 560.95 million m3. After expansion of OTPC plant and additional future demand (for next 10 years) the net available water in the river will be 541.53 million m3.

Figure 3.22 Photographs of Hydrological Survey and Water Uses

Hydrological Survy Consultation with local people

OTPC Water Intake point Lift Irrigation facility


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Fishing activity at Gumti River River bank settlenet and domestic uses Surface Water Quality

Surface Water Monitoring Locations

Surface water was monitored at three different locations from the study area. Samples were collected to understand the potential impact due to proposed project activities. The study area is located at the catchment of Gumti River which is flowing from northeast to southwest at a distance of approximately 2 km from the OTPC plant. Two samples were collected upstream and downstream of the treated water discharge point at Gumti River. Another sample was collected from a stream (Jamjuri Switch Gate Nala) that meets with Gumti River. Water sampling and analysis1 was done following CPCB standard guidelines for physical, chemical and bacteriological parameters. Interpretation of Surface Water Quality Results

The pH of the surface water samples varied from 7.43-7.79. The DO levels at all locations exhibited values ranging from 6.0-6.4 mg/l, indicating favourable conditions for the growth and reproduction fish and other aquatic organisms in these water bodies. Biochemical Oxygen Demand (BOD) values of the sample collected from upstream of intake was found to be 2.9 mg/l. The other samples reveal BOD values of <2.0 mg/l. Such low BOD values confirmed the presence of low concentrations of biologically oxidizable organic matter in the receiving water bodies. Electrical conductivity of the water samples ranged between 117-134 μS/cm. Boron levels of the water samples were found to be <0.5 mg/l. Ammonia in surface water indicates the possibility of sewage pollution and the consequent possible presence of pathogenic micro-organisms. Free ammonia contents of all the samples were found to be less than 0.1 mg/l, indicating absence of sewage pollution in the surface waterbody. Sodium absorption ratio (SAR) of the samples varied between 0.46-0.78.

1 http://www.cpcb.nic.in/latest/guidelines-water.doc


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Presence of contaminants in the form of oil and grease in all surface water samples was found to be negligible (<1.4 mg/l). The total Coliform count of the surface water samples found between 350-920 MPN/100 ml. Concentrations of heavy metal like lead, chromium and cadmium were found to be below detection limits in the surface water sample. Water from the surface water bodies in the study area is used for bathing, washing, catching fish and irrigation. The results of surface water analysis indicated compliance to Class D (Propagation of Wildlife and Fisheries) and Class E (Irrigation, Industrial Cooling, Controlled Waste disposal). Results of surface water quality analysis is presented in the table below:

Table 3.13 Surface Water Quality Analysis

Sl No

Parameter Unit SW-1: Gumti River UP

stream

SW-2: Gumti River

Downstream

SW-3: Jamjuri Switch Gate

Nala 1 Colour Hazen <1.0 <1.0 <1.0 2 pH at 25 deg C None 7.79 7.54 7.43

3 Total Dissolved Solids (as TDS) mg/l 75 85 75.2

4 Boron (as B) mg/l <0.5 <0.5 <0.5 5 Chloride (as Cl ) mg/l 9.80 11.8 11.8 6 Iron (as Fe) mg/l 6.4 4.2 1 7 Sulphate ( as SO4 ) mg/l <1 7.38 6.70

8 Total Hardness (as CaCO3 ) mg/l 56 52 44

9 Cadmium (as Cd) mg/l <0.001 <0.001 <0.001 10 Lead (as Pb ) mg/l <0.005 <0.005 <0.005 11 Arsenic( as As) mg/l <0.01 <0.01 <0.01 12 Electrical conductivity μS/cm 117 134 117

13 Sodium Adsorption Ration (as SAR) --- 0.46 0.54 0.78

14 Total Suspended Solid (as TSS) mg/l 94 82 23

15 Dissolved Oxygen mg/l 6.2 6.0 6.4

16 Biochemical Oxygen Demand (as BOD) mg/l 2.9 <2.0 <2.0

17 Chemical Oxygen Demand (COD) mg/l 20 12 8

18 Oil and Grease mg/l <1.4 <1.4 <1.4

19 Salinity in respect to KCl eqv. 35 --- 0.067 0.077 0.067

20 Free Ammonia mg/l <0.1 <0.1 <0.1 21 Chromium mg/l <0.01 <0.01 <0.01 22 Faecal coliform /100ml Present Present Present

23 Total coliform MPN/100ml 920 350 540



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Geo-Hydrogeology

Water Bearing Formations

There are three hydrogeological units / water bearing formations identified in the undivided South Tripura district (of which Gomati District is a part) are Alluvial formation, Dupitila formation and Tipam formation. The details of the water bearing formations are as follows: Alluvial formation: It occurs along the banks of main rivers and its thickness varies from 10 to 15 m. Ground water occurs under unconfined condition. Ground water development in the area has not been very significant because of high clay and sandy clay content. Ground water is developed through dug wells and ordinary hand pumps. This type of formation covers most of the study area along the banks of Gumti River. Dupitila formation: Dupitila formation is nearly horizontal in disposition and its thickness varies from 10 to 30m. The formation consists of mainly clay and silt with some intercalations of gritty and ferruginous sandstones. In general, it has low permeability and low storage capacity due to high clay content. It has been developed through dug wells and hand pumps. Tipam formation: This formation consists of sub-rounded, fine to medium grained, friable sandstone with intercalated clay. The permeability of this sandstone is much higher than that of Dupitila sandstone or Surma sandstone. The recharge area of the sandstone is in the anticlinal hills. Ground water occurs under semi-confined to confined conditions. This sandstone is developed by deep tubewells and shallow tubewells. Groundwater Resources

Groundwater in the state of Tripura is primarily used for agricultural activities, drinking and other domestic purposes. Groundwater is primarily tapped by tube wells from depths ranging mostly between 35-70 m. A decadal (1999 to 2009) study conducted by CGWB shows that ground water depth also varies during pre-monsoon and post monsoon period. The existing status of ground water in the different part of the state and projected demand, as per the estimation of Central Ground Water Board (Dynamic Ground Water Resources of India, 2009) has been provided in Table 3.14.

Table 3.14 Groundwater resources in different part of Tripura

Parameter West Tripura South Tripura

North Tripura

Dhalai District

The annual replenishable ground water resources

113095 ham 84770 ham 47944 ham 50921 ham

Net ground water available 101785 ham 79687 ham 45546 ham 46774 ham Net annual ground water draft 10415 ham 3568 ham 1609 ham 760 ham


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Parameter West Tripura South Tripura

North Tripura

Dhalai District

Stage of ground water development

10% 4% 4 % 2%

Projected demand (upto 2025) for use of ground water in domestic and irrigation sector

10526 ham 4910 ham 5334 ham 1922 ham

Projected demand (upto 2025) for use of ground water for irrigation purpose

84125 ham 72797 ham 40038 ham 44822 ham

Source: CGWB The study area is included under South Tripura district as per the administrative districts classification during 2009. From the above Table 3.14, it can be inferred, annual net ground water draft potential (3568 ham) and stage of groundwater development is 4% in undivided South Tripura district. Ground Water Level in Study Area Groundwater fluctuation level fluctuation data was obtained from CGWB office. The study area falls within Matabari and Kakraban Blocks of Gomati District. Quarterly groundwater level data for three (3) stations viz. Kakraban, Dhawajanagar and Garjee Bazaar for three years (2013-2016) collected by CGWB were analysed. Groundwater levels at Kakraban station varied between 3.89-10.25 metre below ground level (m. bgl), while at Dhwajanagar and Garjee Bazaar the water levels varied between 1.92-4.54 m. bgl and 0.69-3.38 m. bgl respectively.

Figure 3.23 Fluctuation of Groundwater Levels in Study Area


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Groundwater Quality

Primary monitoring of ground water quality was considered important in order to understand the probable impacts of the proposed project activities on the sub surface aquifers. Groundwater Sampling Locations

Groundwater samples were collected from 6 different locations. Groundwater was collected from shallow deep tube wells of the study area Refer Figure 3.6 and Table 3.15. The samples were analysed for physicochemical and bacteriological parameters and results were compared with IS:10500 (2012) drinking water standards to identify and interpret any deviation in the statutory limits set for parameters under this standard.

Table 3.15 Ground Water Monitoring Location

Location Code

Location Geographical Coordinates

Selection Criteria

GW-1 Kakraban village 23°29'42.67"N 91°26'44.15"E

To understand the existing baseline

GW-2 Dudhpuskurani village 23°31'0.95"N 91°24'10.15"E

To understand the existing baseline and potential impact from plant

GW-3 Gangachara village 23°30'38.19"N 91°26'23.93"E


GW-4 Amtali village 23°28'27.89"N 91°25'54.77"E


GW-5 Khilpara village 23°30'56.54"N 91°25'34.16"E


GW-6 Palatona bazar 23°29'22.45"N 91°25'9.39"E

To understand the existing baseline and potential impact from plant

Figure 3.24 Photographs of Ground Water Sampling

Ground water monitoring at Kakraban Ground water monitoring at Khilpara Analysis Results of Ground Water Quality

pH of the groundwater samples were found in the range of 5.61-8.13. The water samples collected from Kakraban (5.61), Amtali (6.13) and Palatona Bazaar (6.12) were found to be acidic and less than the IS:10500 (2012) limit of 6.5-8.5.


96

The concentration of total dissolved solids (TDS) in ground water is a measure of its suitability for domestic use. In general, TDS values at 500 mg/l or below is considered to be acceptable for such purpose being specified under IS:10500 drinking water standard. The level of dissolved solids in the groundwater samples (28-150 mg/l) were found to be below the acceptable limit of IS 10500 standards i.e., 500 mg/l. With respect to IS: 10500 standards, acceptable limit of chloride is 250 mg/l while the permissible limit of the said parameter (in absence of alternate source) is 1000 mg/l. At concentration above 250 mg/l chlorides renders a salty taste to water which may be considered to be objectionable in terms of human consumption. The chloride concentration in the ground water samples (13.7-59 mg/l) was found to be in compliance to the acceptable limit. Hardness of water is considered to be an important parameter in determining the suitability of water for domestic uses particularly washing. Total hardness of water is correlated to the presence of bivalent metallic ions viz. calcium and magnesium. Total hardness in the groundwater samples varied from 19.6 mg/l to 88.0 mg/l and were incompliance to the acceptable limit of 200 mg/l. Iron is considered to be an important ground water parameter since at higher concentration it interferes with laundering operations and imparts objectionable stains. Concentration iron in ground water sample ranged from <0.05-0.43 mg/l. Iron concentration in all the samples were in compliance to the acceptable limit (0.3 mg/l) of IS:10500 standards excepting the sample collected from Gangachara village (0.43 mg/l). Fluoride concentration of the samples varied between 0.13-0.30 mg/l, which is in compliance to the acceptable limit of IS:10500 standards (1.0 mg/l). Nitrate and sulphate contents of the groundwater samples varied between <0.5-16.2 mg/l and <1.0-36.4 mg/l and were in compliance to the acceptable limits of IS:10500 for nitrate (45 mg/l) and sulphate (200 mg/l). Mercury, cadmium, lead, zinc and chromium contents in all ground water samples were found to be below detection limits and in compliance to the acceptable limits of IS:10500. Organic pollutants like phenolic compounds, mineral oil, anionic detergent, polychlorinated biphenyls (PCBs) and poly-aromatic hydrocarbons (PAHs) and cyanide contents were found to be below detection limit for all the samples. Coliform are indicators of contamination from sewage and faecal matter. Total coliforms contents of all the samples were found to be <1.8 MPN/100 ml. Faecal coliform were not detected in any of the ground water samples. The detailed results of physicochemical characteristics of groundwater within the study area are presented in Table 3.16. In summary, the baseline groundwater quality in the area is mostly acidic to neutral in nature.


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Groundwater samples collected from few villages were found to be acidic and not fit for drinking as per IS:10500 standards. However, the groundwater is consumed in those villages in absence of any alternative source of drinking water. Iron content of one sample was found to be exceeding the IS standards, which could due to local geological features. The locals of Gangachara village also reported presence of higher iron content in groundwater samples. The groundwater samples did not reveal heavy metal or organic pollution. The bacteriological load was also minimal.


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Table 3.16 Groundwater Monitoring Results

Sl No

Parameters Location Kakraban village

Dudhpuskarani village

Gangachara village

Amtali village

Khilpara village

Palatana bazar

Acceptable limit (IS:10500, 2012)

Permissible limit (IS:10500, 2012)

1. Aluminium ( as Al ) mg/l <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.03 0.2 2. Ammonia (as NH3) mg/l <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 0.5 No relaxation 3. Anionic Detergents (as

MBAS) mg/l <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 0.2 1

4. Barium (as Ba ) mg/l <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 0.7 No relaxation 5. Boron (as B) mg/l <0.5 <0.5 <0.5 <0.5 <0.5 <0.5 0.5 1 6. Cadmium (as Cd) mg/l <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 0.003 No relaxation 7. Calcium (as Ca) mg/l 12.6 6.2 11.8 8.0 19.6 15.60 75 200 8. Chloramines (as Cl2) mg/l <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 4 No relaxation 9. Chloride (as Cl ) mg/l 24 13.7 14.7 44 24 59 250 1000 10. Colour Hazen <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 5 15 11. Copper (as Cu) mg/l <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 0.05 1.5 12. Cyanide ( as CN) mg/l <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.05 No relaxation 13. Faecal coliform /100ml Absent Absent Absent Absent Absent Absent Absent No Relaxation 14. Fluoride ( as F ) mg/l 0.15 0.14 0.23 0.13 0.17 0.30 1 1.5 15. Free Residual

Chlorine mg/l <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 0.2 1

16. Iron (as Fe) mg/l 0.07 0.12 0.43 <0.05 <0.05 <0.05 0.3 No relaxation 17. Lead (as Pb ) mg/l <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 0.01 No relaxation 18. Magnesium (as Mg) mg/l 9 0.98 9.5 7.0 7.0 12 30 100 19. Manganese (as Mn) mg/l 0.04 <0.02 0.85 0.04 <0.02 0.44 0.1 0.3 20. Mercury (as Hg ) mg/l <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 0.001 No Relaxation 21. Mineral Oil mg/l <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.5 No relaxation 22. Nitrate (as NO3 ) mg/l 16.2 1.58 <0.5 2.66 5.03 9.15 45 No relaxation 23. Odour - Unobjectio

nable Unobjectionable

Unobjectionable

Unobjectionable

Unobjectionable

Unobjectionable

Agreeable Agreeable

24. pH at 25 deg c - 5.61 7.2 8.13 6.13 7.13 6.12 6.5 - 8.5 No relaxation 25. Phenolic Compounds

( as C6H5OH) mg/l <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 0.001 0.002

26. Polychlorinated biphenyls (as PCB)

mg/l <0.0005 <0.0005 <0.0005 <0.0005 <0.0005 <0.0005


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Sl No

Parameters Location Kakraban village

Dudhpuskarani village

Gangachara village

Amtali village

Khilpara village

Palatana bazar

Acceptable limit (IS:10500, 2012)

Permissible limit (IS:10500, 2012)

27. Polynuclear Aromatic Hydrocarbons ( as PAH )

mg/l <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001

28. Sulphate ( as SO4 ) mg/l <1.0 <1.0 16.04 <1.0 36.47 10.06 200 400 29. Sulphide (as S) mg/l <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.05 No relaxation 30. Total Alkalinity (as

CaCO3) mg/l 19.6 7.84 78 19.6 39 19.6 200 600

31. Total Chromium ( as Cr )

mg/l <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 0.05 No relaxation

32. Total coliform count MPN/100ml

< 1.8 < 1.8 < 1.8 < 1.8 < 1.8 <1.8 Absent No relaxation

33. Total Dissolved Solids (as TDS)

mg/l 79 28 123 92.1 133 150 500 2000

34. Total Hardness (as CaCO3 )

mg/l 69 19.6 69 49 78 88 200 600

35. Turbidity N.T.U. 1 8 30 <1 2 1 1 5 36. Zinc (as Zn) mg/l <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 5 15



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3.3 BIOLOGICAL ENVIRONMENT

3.3.1 Introduction

The Tripura state is located in the Bio-geographic zone of 9B-North-East Hills and is extremely rich in bio-diversity. Situated in the Indian sub-region of Oriental Zoo-geographic region, local flora and fauna bear a very close affinity and resemblance with floral and faunal components of Indo-Malayan and Indo-Chinese sub-regions. As per approved ToR for the proposed expansion project from MoEFCC, Biodiversity and Ecological study was conducted through Centre for Environment and Development (CED)- group of ecologist especially familiar with biota of Tripura and North-East. Two season (pre-monsoon and Post monsoon) ecological study was conducted by CED team. The finding of the ecological survey is presented in following sections.

3.3.2 Objectives of the Study

The ecological surveys were conducted with following objectives: Identification of floral species (terrestrial and aquatic), sensitive habitats, endangered species and forest land falling within the study area; Classification of flora for any endangered or protected species or endemic floral species prevailing in the study area based on field surveys; Identification of aquatic flora in the water bodies falling in the study area. Identification of fauna (specifically amphibians, birds, mammals and reptiles); Identification and classification of any species recognized as threatened (in accordance with International Union for the Conservation of Nature [IUCN] Red List ver. 2017-1), or according to the schedules of the Wildlife (Preservation) Act 1972 and amendments); Identification of areas which are important or sensitive for ecological reasons including their breeding, nesting, foraging, resting, over wintering areas including wildlife migratory corridors /avian migratory routes; and Identification and assessment of aquatic ecological resources within the study area

3.3.3 Methodology

The baseline ecology survey methodology adopted by CED is as follows: Desktop Review

A desktop review (published document, etc.) was conducted to determine the forest area (Toposheet and Satellite imagery), vegetation type (Champion and Seth, 1968), floral and faunal assemblage in the study area.


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Baseline Survey

Baseline survey was carried out to determine the existing ecological conditions and was designed to fill any data gaps, and to facilitate an adequate assessment of the project’s impacts upon ecology and the development of appropriate mitigation measures. Baseline survey was conducted on 05th-07th April 2017 for habitat survey, flora & faunal assemblage, in the study area. Baseline survey has two part- (i) Secondary data collection and (ii) Primary Survey. Secondary Data Collection

Secondary baseline data regarding sensitive ecological habitat (National Park, Sanctuary, Ecological Sensitive Area, Migratory Corridor, etc.), flora & fauna in the study area, forest cover was collected from Forest Working Plans and other publishes and unpublished documents. Stakeholder consultations (Forest Department, Local People etc.) were also carried out to understand the major flora & fauna in the study area, pressure on forest resources, presence of any Schedule I species. Primary Survey

The two season (pre-monsoon and Post monsoon) primary baseline survey was conducted CED team. The study area is located in the forest area, plantations, riparian vegetation and homestead plantations. The major habitats identified in the study area include forests, block plantations, homestead vegetation, agricultural lands, river & water bodies. Habitat specific vegetation survey was undertaken to identify the flora and faunal species in the study area. The following ecological component was surveyed during study period:

Ecological Habitat; Flora: walkthrough and transect & quadrant- 39 sampling plots were identified in different habitats in the study area for quantitative assessment of flora; Faunal survey includes: butterflies & moths, mammals, birds, reptlies, amphibians, fishes; Plankton and benthos in River Gumti.

The detailed ecological survey methodology is presented in Annex-B: Biodiversity and Ecological Survey. The ecological study area and sampling location is presented in following figure.


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Figure 3.25 Ecological Study Area and Sampling Location Map


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3.3.4 Terrestrial Ecosystem

Forest Resources

The recorded forest area of the state is 6294 sq. km, which constitutes 60.02% of its geographical area. The recorded forest land in the Gomati district is 1012.62 sq. km (72.7% of total geographical area). The natural forest located in the study area include three Reserved Forests viz. Chandrapur R.F., Radhakishorepur R. F and Garjee R.F. Apart from that few unclassed forest areas are also located within the study area. Vegetation Types

The important forest types found in study area (Source: Forest Types of India 19681 by Champion and Seth) are presented in Table 3.17.

Table 3.17 Vegetation Types in the Study Area

S No Types of Forest 1. Cachar Tropical Evergreen Forests (I/I/IB/C3) 2. Moist Mixed Deciduous Forests (I/I/3/3C/C3) 3. Secondary Moist Bamboo Brakes (I/I/2/2B/2SI) 4. East Himalayan Lower Bhabar Sal (I/I/3/3C/CIb) 5. Eastern Heavy alluvium plains Sal (I/3/3C/C2/2d/(iii)

Cachar Tropical Evergreen Forests: This type of forest is found in low lying areas of the division where soil moisture is moderate or high. The garjan forests and the other evergreen tree forests of the areas are included in this type. The garjan (Dipterocarpus turbinatus) is seen to have its associates like kanak (Schima wallichii), jam (Syzigium cumini), bahera (Terminalia belerica), awal (Vitex peduncularis), jarul (Lagerstremia parviflora), etc. in several places. Moist Mixed Deciduous Forests: These forests are comprised of deciduous and evergreen trees. The deciduous trees are significantly present. The high hills are seen to have mostly deciduous trees. The evergreen trees are seen to have their presence in low hills, undulated lands and flat tilas. Three distinct stories in good density areas of the forests are noticed. The top story consists of kanak (Schima wallichi), jam (Syzigium cumini), karai (Albizia procera), jarul (Lagerstreomia parviflora), chhatian (Alstonia scholaris) etc. The middle story consists of hargaza (Dillenia pentagyna), kumira (Careya arborea), bhadi (Lannea grandis), chhotamel (Sapium baccatum), medda (Trewia nudiflora), pichla (Grewia microcos) kaimala (Odina wodier), kajikara (Garuga pinnata) etc. The undergrowth consists of Eupotarium, Melastomia, Mecaranga, Strablus asper, Clerodendron infortunatun, acacias etc. Secondary Moist Bamboo Brakes: This type of bamboo forest is found to exist in parts of semi-evergreen forests. This type of bamboo forest has low spreading

1 Champion H. & Seth S.K., 1968, A Revised Survey of the Forest Types of India, Nataraj Publishers, Dehradun, India.


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habit and usually do not allow other vegetation to grow under them. Pecha (Dendrocalamus hamiltonaii), makal (Bambusa pallida), dolu (Schizostachium dullooa), bari (Bambusa polymorpha), barak (Bambusa balcooa), etc. valuable bamboos grow in these forest. East Himalayan Lower Bhabar Sal: This type is characterized by tall and high sal trees, where the soil is deep, loamy and well drained. The sal forests are seen to have three distinct stories in many places. The top story consists of sal and kanak (Schima wallichii). The principal associates are bahera (Terminalia belerica), arjun (Terminalia arjuna), chamal (Artocarpus chaplasa), karai (Albizia procera), gamar (Gmelina arborea), jam (Syzigium cumini), neur (Bursera serrata), etc. A moderate to thin middle story is found to exist with the species mainly hargaza (Dilleniya pentagyna), jinari (Premna bangalensis), sidha jaral (Lagersroemia parviflora), Shonal (Casia fistula), amlaki (Emblica officinalis), etc. the undergrowth consists of bhait (Clerodendron viscosum), Flemengia, Eupatorium, thatch (Imperata cylendrica), etc.

Figure 3.26 Photographs of Natural Forest

Sal Forest: Chandrapur R.F Sal Forest: Radhakishorepur R. F

Modified Habitat

Vegetation are also recorded in the non-forest are of the study area. Tree species in these sites are mostly planted and few are natural. The village woodlot, road side plantation and riparian vegetation are recorded in the study area. These are as follows: Village Woodlot: Naturally or planted trees on community or private land. Bamboo and timber woods are planted in this area. Some important tree species are Schima wallichi, Mangifera indica, Azadirachta indica, Delonix regia, Dalbergia sisso, Ficus religiosa, Syzigium cumini, Ficus benghalensis, Gmelina arborea, etc. Road side Plantation: Trees planted along the major roads in the study area. Some important tree species are Alstonia scholaris, Aegle mermelos, Azadirachta indica, Artocarpus heterophyllus, Bombax ceiba, Delonix regia, Ficus religiosa, Mangifera indica, Lagerstroemia speciose.


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Riparian Vegetation: Vegetation along river bank, major plant species are Ficus benghalensis, Anthocephalus sinensis, Alstonia scholaris, Bombax ceiba, Terminalia arjuna, Syzigium cumini etc. Rubber Plantation: The commercial plantation of rubber is recorded in 71.46 sq. km in the study area (22.75% of total study area; i.e. 314 sq. km).

Figure 3.27 Photographs of Modified Habitat

Paddy Cultivation land near OTPC Plant Riparian vegetation near Gumti River

Village woodlot Rubber Plantation

Floral Diversity

Important flora in the study area are Schima wallichi, Syziguim cuminii, Albizia procera, Artocarpas chaplasa, Lagerstromia parviflora, Alstonia scholaris, Dillenia pentagyna, Amoora wallichii, Cedrella toona, Sapium baccatum, Trewia nudiflora, etc. Bamboo: A total of 19 species of bamboo are reported in the state. Species of bamboo found in Tripura are Barak (Bambusa balcooa), Bari (Bambusa polymorpha), Mritinga (Bambusa tulda), Muli (Melocanna baccifera), Kai (Bambusa nutans), Paora (Bambusa teres), Rupai (Dendrocalamus longispathus), Dolu (Neohuzeaua dullooa), Makal (Bambusa pallida), Pecha (Dendrocalamus hamiltonii), Kailyai (Oxytenanthera nigrociliata), Kanak kaich (Bambusa offinis), Lanthi bans (Dendrocalamus strictus), Tetua (Bambusa spp.), Ish (Bambusa spp.), Jai (Bambusa spp.), Bombash (Bambusa spp.), Sairil/Wadu bamboo (Melocalamus compactiflorus), Bosai (Bambusa spp.) Cane: A total of six (6) cane species are reported from Tripura (Calamus viminalis, C. floribundus, C. tenuis, C. leptospadix, C. guruba, C. erectus). However,


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no estimates on the existing growing stock of aforesaid cane species are available. Plant Diversity: 196 plant species were recorded during two season primary ecological survey. Out of 196 plant species, 56 species of trees, 49 species of shrubs, 81 species of herbs & climbers, 6 species of grass and 4 species of fern. The detailed listing of floral species recorded in the study area is given in Annex-B: Biodiversity and Ecological Survey Report. Phyto-sociology

Predominantly five terrestrial habitats were observed within the study area, which include natural forest, rubber plantation, homestead plantation and agricultural land. These habitats were selected for the phytosociological study. Habitat wise phytosociological characteristics of the above mentioned forests are discussed in the section below: Status of Trees Species Status of tree species is discussed based on Important Value Index (IVI) calculated by adding Relative frequency (RF), Relative density (RDN) and Relative Dominance (RDO) values.

Table 3.18 Phytosociological Characteristics of Tree Species

Sl. No.

Forest / Tree Species Relative Abundance

Relative Frequency

Relative Dominance

IVI

A. Chandrapura R.F -1 1 Sal 80.30 33.3 91.2 204.8 2 Chaplash 6.57 22.2 8.8 37.6 3 Kumbhi 4.38 11.1 0.2 15.7 4 Konak 4.38 22.2 0.7 27.3 5 Boyra 4.38 11.1 0.7 16.2 B. Radhakishorepur

RF

1 Sal 67.2 27.3 83.4 177.9 2 Jam 12.3 18.2 8.8 39.4 3 Chaplash 12.3 27.3 8.8 48.4 4 Kurchi 4.1 9.1 0.2 13.4 5 Amla 4.1 18.2 0.1 22.4 C. Chandrapura R.F -2 1 Sal 65.7 30.0 52.0 147.7 2 Jam 10.6 20.0 2.8 33.4 3 Chaplash 16.4 30.0 37.0 83.5 4 Konak 7.0 20.0 8.2 35.3 D. Gorgee RF 1 Sal 43.8 20.0 94.1 157.9 2 Kumbhi 11.2 13.3 1.3 25.8 3 Jam 3.2 6.7 0.7 10.6 4 Konak 27.2 13.3 1.8 42.3 5 Kurchi 4.8 13.3 1.0 19.1 6 Pichla 3.2 13.3 0.2 16.7 7 Bohera 3.2 6.7 0.3 10.2 8 Siddha 3.2 13.3 0.2 16.7 E. Rubber Plantation-1 1 Rubber 74.5 97.7 97.7 222.1


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Sl. No.


Relative Frequency

Relative Dominance

IVI

2 Shegun 15.2 10.9 10.9 42.8 3 Shupari 5.1 1.2 1.2 22.9 4 Pichla 5.1 2.5 2.5 24.2 F. Rubber Plantation -2 1 Rubber 79.3 60.0 107.4 246.6 2 Pichhla 21.0 40.0 2.6 63.6 G. Agricultural Land-1 1 Areca catechu 37.0 16.7 4.7 58.4 2 Cedrela toona 7.4 16.7 14.5 38.6 3 Ficus hispida 11.1 16.7 10.5 38.3 4 Lannea coromandelica 14.8 16.7 29.0 60.5 5 Psidium guajava 11.1 16.7 1.8 29.6 6 Trewia nudiflora 18.5 16.7 42.8 78.0 H. Agricultural Land-2 1 Lagerstroemia speciosa 9.7 16.7 11.8 38.2 2 Mangifera indica 12.9 16.7 3.4 33.0 3 Phoenix sylvestris 9.7 16.7 0.9 27.3 4 Schima wallichii 25.8 16.7 24.2 66.7 5 Shorea robusta 29.0 16.7 38.5 84.2 6 Syzygium cuminii 12.9 16.7 24.7 54.2 I. Homestead

Plantation-1

1 Aegle marmelos 5.1 5.3 1.7 12.0 2 Areca catechu 30.8 15.8 20.7 67.3 3 Artocarpus

heterophyllus Linn. 10.3 10.5 6.8 27.5

4 Borassus flabellifer 7.7 10.5 18.1 36.4 5 Citrus aurantifolia 7.7 10.5 1.4 19.6 6 Cocos nucifera 10.3 10.5 15.8 36.6 7 Mangifera indica 7.7 10.5 5.0 23.2 8 Phoenix sylvestris 7.7 10.5 5.0 23.2 9 Tectona grandis 7.7 10.5 47.5 65.7 10 Ziziphus mauritiana 5.1 5.3 1.4 11.8 J. Homestead

Plantation-2

1 Aegle marmelos 5.7 10.0 3.4 19.1 2 Areca catechu 34.3 15.0 13.9 63.2 3 Artocarpus

heterophyllus 5.7 10.0 12.1 27.8 4 Citrus aurantifolia 11.4 5.0 0.7 17.1 5 Dillenia indica Linn. 5.7 10.0 3.3 19.0 6 Emblica officinalis 5.7 5.0 2.3 13.0 7 Mangifera indica 8.6 10.0 18.1 36.7 8 Psidium guajava 5.7 10.0 1.5 17.3 9 Syzygium cuminii 5.7 10.0 20.0 35.7 10 Tamarindus indica 5.7 5.0 13.2 23.9 11 Ziziphus mauritiana 5.7 10.0 4.6 20.3 K. Gumti River Side-1 1 Alstonia scholaris 4.32 4.8 2.1 11.2 2 Areca catechu 12.95 4.8 0.3 18.0 3 Artocarpus

heterophyllus 4.32 4.8 0.3 9.4 4 Bombax ceiba 4.32 4.8 1.9 10.9 5 Cocos nucifera 8.63 4.8 1.7 15.1 6 Delonix regia 4.32 4.8 0.8 9.9 7 Erythrina variegata 4.32 4.8 0.7 9.8 8 Eugenia fruiticosa 4.32 4.8 0.5 9.6 9 Ficus benghalensis 4.32 4.8 13.6 22.7 10 Gmelina arborea 4.32 4.8 3.4 12.5 11 Litsea sp, - Lauraceae 4.32 4.8 6.1 15.2 12 Mangifera indica 6.47 9.5 26.1 42.1


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Sl. No.


Relative Frequency

Relative Dominance

IVI

13 Melia azedarach 8.63 4.8 9.8 23.2 14 Phoenix sylvestris 8.63 4.8 1.7 15.1 15 Phyllanthus acidus 4.32 9.5 1.1 14.9 16 Terminalia arjuna 4.32 4.8 19.6 28.7 17 Trewia nudiflora 7.19 14.3 8.3 29.8 L. Gumti River Side-2 1 Borassus flabellifer 3.1 3.7 1.7 8.5 2 Cassia fistula Linn. 3.1 3.7 1.5 8.3 3 Citrus maxima 4.7 7.4 2.9 15.0 4 Ficus glomerata 3.1 7.4 1.1 11.6 5 Ficus rumphii 7.8 7.4 86.9 102.0 6 Lannea coromandelica 3.1 3.7 5.1 11.9 7 Melocanna

bambusoides 3.1 3.7 2.9 9.7 8 Moringa oleifera 3.1 3.7 5.1 11.9 9 Polyalthia longifolia 3.1 3.7 7.9 14.7 10 Syzygium fruticosum 6.2 3.7 2.5 12.5 11 Tamarindus indica 24.8 3.7 29.3 57.9 12 Toona ciliate 6.2 3.7 2.5 12.5 13 Trewia nudiflora 6.2 3.7 4.0 13.9 14 Ziziphus mauritiana 4.7 7.4 15.2 27.3 M. Gumti River Side-3 1 Artocarpus

heterophullus 6.4 13.0 12.4 31.9 2 Averrhoa bilimbi 4.8 4.3 1.6 10.7 3 Bambusa balcooa 32.1 13.0 3.7 48.8 4 Borassus flabellifer 19.2 13.0 82.4 114.6 5 Cassia fistula 7.2 8.7 2.2 18.1 6 Momordica

cochinchinensis 4.8 4.3 0.7 9.9 7 Moringa oleifera 4.8 4.3 2.6 11.7 8 Syzygium fruticosum 4.8 4.3 3.2 12.4 9 Tamarindus indica 4.8 8.7 9.2 22.7 10 Trewia nudiflora 6.4 13.0 2.0 21.5 11 Ziziphus mauritiana 4.8 13.0 1.2 19.1

[Source: Ecological Survey conducted by CED, 2017] Chandrapura R.F -1: Among 5 recorded species in the Chandrapura RF; the most dominant species was Sal with IVI 204.8. This is followed by Chaplash (37.6), Konak (27.3), Boyra (16.2) and Kumbhi (15.7). Radhakishorepur R.F: Among 5 recorded species in the Radhakishorepur RF; the most dominant species was Sal with IVI 177.9. This is followed by Chaplash (48.4), Jam (39.4), Amla (22.4) and Kurchi (13.4). Chandrapura R.F -2: Among 4 recorded species in the Chandrapura RF; the most dominant species was Sal with IVI 147.7. This is followed by Chaplash (83.5), Konak (35.3) and Jam (33.4). Gorgee R.F: Among 8 recorded species in the Gorgee R.F; the most dominant species was Sal with IVI 157.9. This is followed by Konak (42.3), Kumbhi (25.8), Kurchi (19.1), Pichla and Siddha (16.7), etc.


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Rubber Plantation-1: Among 4 recorded species in the Rubber plantation; the most dominant species was Rubber with IVI 222.1. This is followed by Shegun (42.8), Pichla (24.2) and Supari (22.9). Rubber Plantation-2: Among 2 recorded species in the Rubber plantation; the most dominant species was Rubber with IVI 246.6. This is followed by Pichla (63.6). Agricultural land-1: Among 6 recorded species in the Agricultural land; the most dominant species was Trewia nudiflora with IVI 78.0. This is followed by Lannea coromandelica (60.5), Areca catechu (58.4), Cedrela toona (38.6) and Psidium guajava (29.6). Agricultural land-2: Among 6 recorded species in the Agricultural land; the most dominant species was Shorea robusta with IVI 84.2. This is followed by Schima wallichii (66.7), Syzygium cuminii (54.2), Lagerstroemia speciosa (38.2) and Mangifera indica (33.0). Homestead Plantation-1: Among 10 recorded species in the Homestead plantation; the most dominant species was Areca catechu with IVI 67.3. This is followed by Tectona grandis (65.7), Cocos nucifera (36.6), Artocarpus heterophyllus(27.5) and Mangifera indica (23.2), etc. Homestead Plantation-2: Among 10 recorded species in the Homestead plantation; the most dominant species was Areca catechu with IVI 63.2. This is followed by Mangifera indica (36.7), Syzygium cuminii (35.7), Artocarpus heterophyllus (27.8) and Tamarindus indica (23.9), etc. Gumti River Side-1: Among 17 recorded species in the Gumti River Side-1; the most dominant species was Trewia nudiflora with IVI 29.8. This is followed by Melia azedarach (23.2),Ficus benghalensis (22.7),Areca catechu (18.0) and Litsea sp, (15.2), etc. Gumti River Side-2: Among 14 recorded species in the Gumti River Side-2; the most dominant species was Ficus rumphii with IVI 102.0. This is followed by Tamarindus indica (57.9), Ziziphus mauritiana (27.3), Citrus maxima (15.0), Polyalthia longifolia (14.7) . Gumti River Side-3: Among 2 recorded species in the Gumti River Side-3; the most dominant species was Borassus flabellifer with IVI 114.6. This is followed by Bambusa balcooa(48.8), Artocarpus heterophullus (31.9), Tamarindus indica (22.7), Trewia nudiflora (21.5), etc.. Status of Shrubs

Status of woody shrub was assessed based on Relative Value Index (RVI). Relative important value indexes the added value of only Relative Frequency and Relative Density. The calculated RVIs are presented in Table 3.19.


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Table 3.19 Phytosociological Characteristics of Shrub Species

Sl. No.

Forest/Shrub Species Relative Density Relative Frequency

RVI

A. Chandrapura R.F -1 1 Bhaht 56.75 37.5 94.2 2 Pichhla 3.20 25.0 28.2 3 Eupetorium 39.97 37.5 77.5 B. Radhakishorepur RF 1 Pichhla 10.7 50.0 60.7 2 Bhaht 89.1 50.0 139.1 C. Chandrapura R.F -2 1 Bhaht 82.9 42.8 125.8 2 Pichhla 7.7 28.6 36.2 3 Acacia 3.1 14.3 17.4 4 Urena lobata 6.1 14.3 20.4 D. Gorgee RF 1 Pichhla 60.6 66.7 127.3 2 Urena lobata 40.4 33.4 73.8 E. Rubber Plantation-1 1 Bhutraj 40.4 60.0 100.4 2 Pichhla 60.6 40.0 100.6 F. Rubber Plantation-2 1 Urena lobata 74.1 66.7 140.8 2 Cassia occidentalis 24.7 33.4 58.1 G. Agricultural Land-1 1 Cassia occidentalis 14.2 18.2 32.4 2 Chromolaena odorata 28.5 27.3 55.8 3 Clerodendrum viscosum 28.5 18.2 46.7 4 Colocasia esculenta 19.9 18.2 38.1 5 Crotalaria sp. 8.5 18.2 26.7 H. Agricultural Land-2 1 Cassia occidentalis 19.2 28.6 47.7 2 Chromolaena odorata 42.1 42.8 85.0 3 Clerodendrum viscosum 38.3 28.6 66.9 I. Homestead Plantation-1 1 Colocasia esculenta 37.0 40.0 77.0 2 Sesamum indicum 61.7 60.0 121.7 J. Homestead Plantation-2 1 Colocasia esculenta (Linn.) Schott 77.8 60.0 137.7 2 Solanum melongena Linn. 22.2 40.0 62.2 K. Gumti River Side-1 1 Ficus hispida 33.33 50.1 83.4 2 Glycosmis pentaphylla 11.11 25.0 36.1 3 Ipomoea carnea 55.56 25.0 80.6 4 Kirganelia reticulata 77.78 75.1 152.9 5 Musa sp. 33.33 25.0 58.4 6 Nyctanthes arbor-tristis 22.22 25.0 47.2

L Gumti River Side-2


111

Sl. No.


RVI

1 Calotropis gigantea 58.0 50.1 108.0 2 Ficus hispida 43.5 50.1 93.5 M Gumti River Side-3 1 Elaeocarpus serratus 51.3 33.4 84.6 2 Toona ciliate 51.3 66.7 118.0

[Source: Ecological Survey conducted by CED, 2017] Chandrapura R.F -1: Among 3 recorded species in the Chandrapura RF; the most dominant species was Bhant with IVI 94.2. This is followed by Eupetorium (77.5) and Pichhla (28.2). Radhakishorepur R.F: Among 2 recorded species in the Radhakishorepur RF; the most dominant species was Bhant with IVI 139.1. This is followed by Pichhla (60.7). Chandrapura R.F -2: Among 4 recorded species in the Chandrapura RF; the most dominant species was Bhant with IVI 125.8. This is followed by Pichhla (36.2), Urena lobata (20.4) and Acacia (17.4). Gorgee R.F: Among 2 recorded species in the Gorgee R.F; the most dominant species was Pichhla with IVI 127.3. This is followed by Urena lobata (73.8). Rubber Plantation-1: Among 2 recorded species in the Rubber plantation; the most dominant species was Pichhla with IVI 100.6. This is followed by Bhutraj (100.4). Rubber Plantation-2: Among 2 recorded species in the Rubber plantation; the most dominant species was Urena lobata with IVI 140.8. This is followed by Cassia occidentalis (58.1). Agricultural land-1: Among 5 recorded species in the Agricultural land; the most dominant species was Chromolaena odorata with IVI 55.8. This is followed by Clerodendrum viscosum (46.7), Colocasia esculenta (38.1), Cedrela toona (32.4) and Crotalaria sp. (26.7). Agricultural land-2: Among 3 recorded species in the Agricultural land; the most dominant species was Chromolaena odorata with IVI 85.0. This is followed by Clerodendrum viscosum (66.9), and Cassia occidentalis (47.7). Homestead Plantation-1: Among 2 recorded species in the Homestead plantation; the most dominant species was Sesamum indicum with IVI 121.7. This is followed by Colocasia esculenta (77.0). Homestead Plantation-2: Among 2 recorded species in the Homestead plantation; the most dominant species was Colocasia esculenta with IVI 137.7. This is followed by Solanum melongena (62.2).


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Gumti River Side-1: Among 6 recorded species in the Gumti River Side-1; the most dominant species was Kirganelia reticulata with IVI 152.9. This is followed by Ficus hispida (83.4),Ipomoea carnea(80.6),Musa sp. (58.4) and Nyctanthes arbor-tristis (47.2), etc. Gumti River Side-2: Among 2 recorded species in the Gumti River Side-2; the most dominant species was Nyctanthes arbor-tristis with IVI 47.2. This is followed by Glycosmis pentaphylla (36.1). Gumti River Side-3: Among 2 recorded species in the Gumti River Side-3; the most dominant species was Toona ciliate with IVI 118.0. This is followed by Coix Elaeocarpus serratus (84.6). Status of Herbs

Status of herbs was assessed based on Relative Value Index (RVI). Relative important value indexes the added value of only Relative Frequency and Relative Density. The calculated RVIs are presented in Table 3.20.

Table 3.20 Phytosociological Characteristics of Herb Species

Sl. No.


RVI

A. Chandrapura R.F -1 1 Ground yellow orchid 7.94 50.1 58.0 2 Dioscorea sp. 92.06 50.1 142.1 B. Radhakishorepur RF 1 Bhutraj 59.5 50.0 109.5 2 Aerides 40.5 50.0 90.5 3 Yellow ground orchid 6.0 33.3 39.3 4 Commelina 14.3 33.3 47.6 C. Chandrapura R.F -2 1 Job’s tear 81.9 21.4 103.3 2 Bhutraj 4.1 14.3 18.4 3 Aerides 1.7 7.1 8.8 4 Yellow ground orchid 2.5 7.1 9.6 5 Commelina 3.3 14.3 17.6 6 Touch me not 0.8 7.1 8.0 7 Ramdatan 2.5 14.3 16.8 8 Urena lobata 3.3 14.3 17.6 D. Gorgee RF 1 Dioscorea 85.7 60.0 145.7 2 Commelina 14.3 40.0 54.3 3 Yellow ground orchid 9.5 20.0 29.5 4 Colocacia 9.5 20.0 29.5 E. Rubber Plantation-1 1 Bhutraj 40.4 60.0 100.4 2 Pichhla 60.6 40.0 100.6 F. Rubber Plantation-2 1 Mainden hair fern 209.9 66.7 276.6


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Sl. No.


RVI

2 Grass 24.7 33.4 58.1 G. Agricultural Land-1 1 Ipomoea carnea 19.4 10.0 29.4 2 Chrysopogon aciculatus 36.0 15.0 51.0 3 Achyranthes aspera 10.1 10.0 20.1 4 Ageratum conyzoides 4.3 10.0 14.3 5 Cardiospermum halicacabum 1.4 5.0 6.4 6 Cassia tora 17.3 10.0 27.3 7 Leucas aspera 3.6 10.0 13.6 8 Ocimum basilicum 3.6 10.0 13.6 9 Ocimum sanctum 1.4 5.0 6.4 10 Sida rhombifolia 1.4 5.0 6.4 11 Solanum sp. 1.4 10.0 11.4 H. Agricultural Land-2 1 Cassia tora 37.6 23.1 60.6 2 Leucas aspera 14.1 23.1 37.2 3 Ocimum basilicum 7.8 15.4 23.2 4 Ocimum sanctum 3.1 7.7 10.8 5 Sida rhombifolia 3.1 7.7 10.8 6 Achyranthes aspera 34.4 23.1 57.5 I. Homestead Plantation-1 1 Cucurbita maxima Duchesne 44.4 37.5 81.9 2 Luffa acutangula (Linn.) Roxb. 16.7 25.0 41.7 3 Momordica cochinchinensis Spreng. 5.6 12.5 18.1 4 Musa paradisiaca Linn. 33.3 25.0 58.3 J. Homestead Plantation-2 1 Cucurbita maxima Duchesne 2.4 25.0 27.4 2 Luffa acutangula (Linn.) Roxb. 4.8 50.1 54.8 3 Momordica charantia Linn. 2.4 25.0 27.4 4 Bambusa sp. 59.5 50.1 109.6 5 Curcuma domestica Valeton 19.0 50.1 69.1 6 Dioscorea sp. 3.6 50.1 53.6 7 Zingiber officinale Rose 8.3 50.1 58.4 K. Gumti River Side-1 1 Alternanthera philoxeroides 6.62 4.0 10.6 2 Alternanthera sessillis 0.74 2.0 2.7 3 Borreria articularis 2.21 2.0 4.2 4 Cardiospermum halicacabum 6.62 4.0 10.6 5 Cassia tora 2.94 2.0 5.0 6 Chromolaena odorata – 2.21 2.0 4.2 7 Chrysopogon aciculatus 2.21 2.0 4.2 8 Clerodendrum viscosum 2.21 2.0 4.2 9 Colocasia esculenta 3.68 4.0 7.7 10 Commelina spp. 5.15 4.0 9.2 11 Crotalaria sp. 2.94 2.0 5.0 12 Croton bonplandianum 2.21 2.0 4.2 13 Desmodium trifoliata 4.42 4.0 8.4


114

Sl. No.


RVI

14 Enhydra fluctuans 4.42 4.0 8.4 15 Heliotropium indicum 2.21 2.0 4.2 16 Lannea coromandelica 3.68 4.0 7.7 17 Leucas aspera 0.74 2.0 2.7 18 Maesa indica 2.21 2.0 4.2 19 Mimosa pudica 1.47 2.0 3.5 20 Ocimum basilicum 2.94 2.0 5.0 21 Oxalis corniculata 1.47 2.0 3.5 22 Peperomia pellucida 5.89 4.0 9.9 23 Phyla nodiflora 2.21 2.0 4.2 24 Scoparia dulcis 7.36 6.0 13.4 25 Sesamum indicum 2.94 4.0 7.0 26 Spilanthes acmella 1.47 2.0 3.5 27 Synedrella nodiflora 1.47 2.0 3.5 28 Typhonium trilobatum 2.21 2.0 4.2 29 Urena lobata 1.47 2.0 3.5 L Gumti River Side-2 1 Chromoleana odorata 1.4 1.9 3.3 2 Dioscorea alata 0.9 1.9 2.8 3 Dioscorea bulbifera 1.4 1.9 3.3 4 Dioscorea esculenta 0.9 1.9 2.8 5 Dioscorea spp. 0.5 1.9 2.3 6 Mikania cordata 10.6 5.7 16.3 7 Momordica cochinchinensis 5.1 3.8 8.8 8 Ageratum conyzoides 3.2 5.7 8.9 9 Amaranthus spinosus 1.4 1.9 3.3 10 Amorphophallus campanulatus 1.4 1.9 3.3 11 Cassia tora 3.2 5.7 8.9 12 Chrysopogon aciculatus 2.3 1.9 4.2 13 Clerodendrum viscosum 4.1 5.7 9.8 14 Coix lacryma-jobi 1.4 1.9 3.3 15 Colocasia esculenta 1.8 1.9 3.7 16 Commelina spp. 1.4 1.9 3.3 17 Croton bonplandianum 2.3 1.9 4.2 18 Cyperus rotundus 1.4 1.9 3.3 19 Cyperus spp. 1.8 1.9 3.7 20 Diplazium esculentum 2.3 1.9 4.2 21 Enhydra fluctuans 1.4 1.9 3.3 22 Eragrostis japonica 1.4 1.9 3.3 23 Euphorbia hirta 2.3 3.8 6.1 24 Glycosmis pentaphylla 1.4 1.9 3.3 25 Kirganelia reticulata 0.9 1.9 2.8 26 Maesa indica 2.3 1.9 4.2 27 Mimosa pudica 7.8 3.8 11.6 28 Oplismenus burmannii 2.3 1.9 4.2 29 Phyllanthus fraternus 9.2 5.7 14.9 30 Physalis minima 2.3 1.9 4.2


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Sl. No.


RVI

31 Pilea sp. 2.8 1.9 4.7 32 Pteridium aquilinum 2.3 1.9 4.2 33 Sesamum indicum 3.7 3.8 7.5 34 Synedrella nodiflora 1.8 1.9 3.7 35 Typhonium trilobatum 5.5 5.7 11.2 36 Urena lobata 3.7 3.8 7.5

Gumti River Side-3 1 Dioscorea esculenta 1.9 6.2 8.2 2 Dioscorea spp. 3.2 6.2 9.4 3 Mikania cordata 6.4 3.1 9.5 4 Ageratum conyzoides 5.7 9.4 15.1 5 Amorphophallus campanulatus 1.3 3.1 4.4 6 Cassia tora Linn. 6.4 9.4 15.7 7 Chromolaena odorata 22.3 9.4 31.7 8 Clerodendrum viscosum 10.8 9.4 20.2 9 Coix lacryma-jobi 15.3 9.4 24.7 10 Commelina spp. 2.5 3.1 5.7 11 Costus speciosus 3.2 3.1 6.3 12 Phyllanthus fraternus 3.2 3.1 6.3 13 Sesamum indicum 5.7 6.2 12.0 14 Typhonium trilobatum 5.7 9.4 15.1 15 Urena lobata 6.4 9.4 15.7

[Source: Ecological Survey conducted by CED, 2017] Chandrapura R.F -1: Among 2 recorded species in the Chandrapura RF; the most dominant species was Dioscorea sp. with IVI 142.1. This is followed by Ground yellow orchid (58.0). Radhakishorepur R.F: Among 4 recorded species in the Radhakishorepur RF; the most dominant species was Bhutraj with IVI 109.5. This is followed by Aerides (90.5), Commelina (47.6) and Yellow ground orchid (39.3). Chandrapura R.F -2: Among 7 recorded species in the Chandrapura RF; the most dominant species was Job’s tear with IVI 103.3. This is followed by Bhutraj (184.4), Commelina & Urena lobata (17.6), Ramdatan (16.8) and Yellow ground orchid (9.6), etc.. Gorgee R.F: Among 4 recorded species in the Gorgee R.F; the most dominant species was Dioscorea with IVI 145.7. This is followed by Commelina (54.3), Yellow ground orchid and Colocacia (29.5). Rubber Plantation-1: Among 2 recorded species in the Rubber plantation; the most dominant species was Bhutraj with IVI 100.6. This is followed by Pichhla (100.4). Rubber Plantation-2: Among 2 recorded species in the Rubber plantation; the most dominant species was Mainden hair fern with IVI 276.6. This is followed by Grass (58.1).


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Agricultural land-1: Among 11 recorded species in the Agricultural land; the most dominant species was Chrysopogon aciculatus with IVI 51.0. This is followed by Ipomoea carnea (29.4), Cassia tora (27.3), Achyranthes aspera (20.1) and Ageratum conyzoides (14.3), etc. Agricultural land-2: Among 6 recorded species in the Agricultural land; the most dominant species was Cassia tora with IVI 60.6. This is followed by Achyranthes aspera (57.5), and Leucas aspera (27.2) etc. Homestead Plantation-1: Among 4 recorded species in the Homestead plantation; the most dominant species was Cucurbita maximawith IVI 81.9. This is followed by Musa paradisiaca (58.3), Luffa acutangula (41.7) and Momordica cochinchinensis (18.1). Homestead Plantation-2: Among 7 recorded species in the Homestead plantation; the most dominant species was Bambusa sp. with IVI 109.6. This is followed by Curcuma domestica (69.1), Zingiber officinale (58.4), Luffa acutangula (54.8) and Dioscorea sp. (53.6) etc. Gumti River Side-1: Among 29 recorded species in the Gumti River Side-1; the most dominant species was Scoparia dulcis with IVI 13.4. This is followed by Alternanthera philoxeroides, Cardiospermum halicacabum (10.6), Peperomia pellucida (9.9),Commelina spp. (9.2) and Desmodium trifoliata (8.4) etc. Gumti River Side-2: Among 36 recorded species in the Gumti River Side-2; the most dominant species was Mikania cordata with IVI 16.3. This is followed by Phyllanthus fraternus (14.9), Mimosa pudica (11.6),Typhonium trilobatum(11.2) and Clerodendrum viscosum (9.8) etc. Gumti River Side-3: Among 15 recorded species in the Gumti River Side-3; the most dominant species was Chromolaena odoratawith IVI 31.7. This is followed by Coix lacryma-jobi (24.7),Clerodendrum viscosum(20.2),Cassia tora Linn. And Urena lobata (15.7) and Ageratum conyzoides (15.1), etc

Species Diversity

Pre-monsoon Season: Species richness was highest in the homestead plantation-1. The lowest richness was observed for Rubber plantation. Highest species diversity for trees was recorded in Gomti River Side-2 with Shannon Wiener Diversity Index Value of 2.6713. This is followed by Gomti River Side-1 (2.671), Gomti River Side-3 (1.8589), homestead plantation-1 (1.9101),Homestead Plantation-2 with diversity index of 1.8534, Agricultural Land-2 (1.6891), Agricultural Land-1 (1.6441), Gorgee RF (1.3296), Chandrapura R.F -2 (0.8988), Chandrapura R.F -1 (0.4970), Rubber Plantation-1 (0.4265) and Rubber Plantation-2 (0.4265). Species diversity indices of the surveyed habitats are presented in Table 3.21. Post-monsoon Season


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Highest species diversity for trees was recorded in Homestead plantation 1 with Shannon Wiener Diversity Index Value of 2.1935. This is followed by Gomti River Side-2 (2.0800), Homestead plantation 2 (1.9098), Agricultural Land-2 (1.6591), Gomti River Side 3 (1.3546), Agricultural land 1 (1.3666), Gomti River side 1 (1.3490), Chandrapur RF 2(0.9475), Radhakishorepur RF (0.9126), Gorgee RF (0.8972) etc.

Table 3.21 Species Diversity Index of the surveyed habitats

Sl. No

Habitat Species Diversity Index: Pre-monsoon Season

Species Diversity Index: Post-monsoon Season

Trees Shrubs Herbs Trees Shrubs Herbs 1 Chandrapura R.F -1 0.4970 0.7979 0.2777 0.8970 0.4101 2.1048 2 Chandrapura R.F -2 0.8988 0.6300 0.8121 0.9475 0.9683 2.2048 3 Radhakishorepur RF 0.8821 0.3405 0.7146 0.9126 1.1166 2.4426 4 Gorgee RF 1.3296 0.6730 0.4909 0.8972 0.8460 1.6291 5 Rubber Plantation-1 0.4265 0.6730 0.6730 0.0516 1.2117 1.9591 6 Rubber Plantation-2 0.4227 0.5623 1.2552 0.4227 1.2552 1.2552 7 Agricultural Land-1 1.6441 1.5714 2.1697 1.3666 0.7039 1.5894 8 Agricultural Land-2 1.6891 1.0485 1.0595 1.6591 1.8609 2.1821 9 Homestead

Plantation-1 1.9101 0.6616 1.1858 2.1935 1.6568 0.5846

10 Homestead Plantation-2

1.8534 1.2516 1.2737 1.9098 1.1579 2.1554

11 Gomti River Side-1 2.671 0.7647 0.2158 1.3490 1.7397 0.7213 12 Gomti River Side-2 2.6713 0.6829 0.1024 2.0800 2.1312 0.5005 13 Gomti River Side-3 1.8589 0.6931 2.4343 1.3546 0.5379 0.5046

[Source: Ecological Survey conducted by CED, 2017] Endemic, Threatened & Endangered Floral Species: The Wildlife (Protection) Act 1972 prohibits picking, uprooting, damaging, destroying, acquiring or collecting six species of plants from forest land and any area specified, by notification, by the Central Government [Clause 17A of Chapter IIIA (Protection of Specified Plants), page 346 of Handbook Vol. 1]. The six species are: Beddome’s cycad (Cycas beddomei), Blue Vanda (Vanda coerulea), Kuth (Sassurea lappa), Ladies slipper orchids (Paphiopedilum spp.), Pitcher plant (Nepenthes khasiana), Red Vanda (Rananthera imshootiana). None of the six species were recorded/reported from the study area. Wildlife Habitat

Tripura is home to a number of mammalian fauna, e.g. Indian Elephant, Gaur, Golden langur, Leopard, Clouded Leopard, Golden Cat, Sloth bear, Hollock Gibbon, Slow Loris, Capped Langur, Phayre’s langur, stump-tailed macaque, pig-tailed macaque, Sambar, Barking deer, etc. Wildlife in Tripura is given protection through a network of 4 Wildlife Sanctuaries namely Sepahijala Wildlife Sanctuary (WLS), Gumti WLS, Trishna WLS and Rowa WLS and two National Parks Clouded Leopard National Park and Rajbari National Park. As per Draft Gazette Notification (S.O 477 (E), dated 10th September 2018), the MoEF&CC proposed that ecosensitive zone of Trishna Wildlife Sactuary is 0.5 km maximum around the sanctuary.


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The ecological sensitivity map of Trishna Wildlife Sanctuary and Sepahijila Wildlife Sactuay map was authenticated by PCCF, Wildlife, Govt. of Tripura. The distance of Trishna Wildlife Sanctuary from the plant is approximately 7.74 km and distance from Sepahijila Wildlife Sactuay is approximately 18.31 km. The authenticated map has been provided in Annex 3.5. Important Bird Area (IBA): The State has four wildlife sanctuaries, namely Gumti, Trishna, Sepahijala and Roa. Only two protected areas are identified as IBAs, Gumti and Trishna. Out of these only Trishna IBA is located within 10 km of the project area. Bison Habitat: The South Western part of the Trishna WLS has a habitat of bison that is protected under Rajbari National Park. The Bison population is concentrated to the south western part of WLS due to the presence of denser canopy forest area. Further, the consultation with the Forest Department revealed that the movement of the bisons towards the Eastern part is restricted due to the presence of hills and fragmented landscape. Bisons are not recorded or reported from the study area. Faunal Diversity

Butterflies& Moths

Mandal et al (2000) provided the first comprehensive account of Lepidopters of Tripura, totally 135 species under 106 genera and 22 families. This report recorded 13 species of butterflies and 29 species of moths for the first time from Tripura. Of the total species (135 spp), at least 54 species have been recorded from Gumti District and adjacent areas of South Tripura. At least 04 species of Butterflies and 16 species of Moths are exclusively known to South Tripura, while other share variable common distribution with other region. The authors however did not indicate and endangered or threatened species from the region. However, Majumder et,al (2012) recorded 59 species of Butterflies in 48 genera and 05families from Tripura Wildlife Sanctuary in South Tripura; it occupies 135 sq km and contain 280 species of tree, 110 species of shrubs, 400 species of herbs and 150 species of Climbers. Nymphyid species showed high percentage and Troides Helena Linn is listed as ‘Endangered’ in CITES Appendix II; However 09 other species viz. Arhopala pseudocentarus (Doubleday), Baoris farri (Moore), Castalius rosimon (Fabricius), Cepora nerissa (Fabricius), Elymnias malelas (Hewitson), Lethe europa (Fabricius), Meaisba malaya (Horsfield), Narathura selta (deNiceville), Pantoporia hordonia (Stoll) are listed in V Schedule I & II of IWPA (1972 but amended till date. Primary Survey

Butterfly and Moth survey was carried out at different habitats like natural forest, homestead plantation, agricultural land, rubber plantation, riparian vegetated areas. 55 species of butterfly and moths was recorded during two season primary ecological survey. Site wise species density and diversity index is presented in following table.


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Table 3.22 Information of Butterflies & Moths collected for the study area

S. No.

Habitat Common Name Scientific Name Density (No./acre)

Diversity Index

A Chandrapur RF 1 1.0686 1 Common Grass

Yellow Eurema hecabe 25

2 Common Emigrant Catopsilia pomona 20 3 Common Pierrot Castalius rosimon 4 4 Plain Tiger Danaus chrysippus 2 B. Radhakishorepur RF 0.8608 1 Common Rose Atrophaneura

aristolochiae 2

2 Common Grass Yellow

Eurema hecabe 16

3 Tree Yellow Gandaca harina 11 4 Common Emigrant Catopsilia pomona 90 5 Mottled Emigrant Catopsilia pyranthe 81 6 Striped Albatross Appias libythea 9 7 Common Albatross Appias albina 4 8 Tiny Grass Blue Zizula hylax 9 9 Striped Tiger Danaus genutia 2 10 Common Crow Euploea core 7 11 Common

Bushbrown Mycalesis mineus 2

12 Grey Count Tanaecia lepidea 2 C. Chandrapur RF 2 0.2681 1 Common Mormon Papilio polytes 7 2 Lime Butterfly Papilio demoleus 2 3 Common Grass


4 Common Emigrant Catopsilia Pomona 22 5 Mottled Emigrant Catopsilia pyranthe 7 6 Common Albatross Appias albina 4 D. Gargee RF 0.8052 1 Common Mormon Papilio polytes 11 2 Yellow Helen Papilio nephelus 4 3 Common Birdwing Troides helena 7 4 Common Grass


5 Common Emigrant Catopsilia pomona 34 6 Mottled Emigrant Catopsilia pyranthe 16 7 Common Albatross Appias albina 4 8 Common


9 Common Crow Euploea core 4 10 Common Sailer Neptis hylus 4 11 Knight Lebadea martha 2 12 Grey Count Tanaecia lepidea 2 13 Chocolate Pansy Junonia iphita 2 E. Rubber Plantation-1 0.4578 1 Chocolate Demon Sancus fuligo 4 2 Common Mormon Papilio polytes 7 3 Yellow Helen Papilio nephelus 7 4 Common Emigrant Catopsilia pomona 11 5 Forest Quaker Pithecops corvus 2 6 Common Crow Euploea core 4 7 Nigger Orsotrioena medus 2 8 Striped Tiger Danaus genutia 4


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S. No.


Diversity Index

9 Chocolate Pansy Junonia iphita 2 10 Danaid Eggfly Hypolimnas misippus 2 F. Rubber Plantation-2 0.1365 1 Common Mormon Papilio polytes 4 2 Common Grass


3 Common Emigrant Catopsilia pomona 13 4 Mottled Emigrant Catopsilia pyranthe 2 G. Agricultural Land-1 0.1525 1 Psyche Leptosia nina 2 2 Common Grass


3 Common Emigrant Catopsilia pomona 18 4 Common Castor Ariadne merione 2 H. Agricultural Land-2 0.2497 1 Lime Butterfly Papilio demoleus 4 2 Psyche Leptosia nina 2 3 Common Emigrant Catopsilia pomona 11 4 Tree Yellow Gandaca harina 7 5 Common


6 Common Castor Ariadne merione 2 I. Homestead Plantation-1 0.0737 1 Psyche Leptosia nina 2 2 Common Grass


3 Common Emigrant Catopsilia Pomona 2 J. Homestead Plantation-2 0.1275 1 Yellow Helen Papilio nephelus 2 2 Psyche Leptosia nina 2 3 Common Emigrant Catopsilia pomona 7 4 Common castor Ariadne merione 4 K. Gumti River Site-1 0.3186 1 Psyche Leptosia nina 8 2 Common Mormon Papilio polytes 5 3 Common Grass


4 Common Emigrant Catopsilia Pomona 10 5 Common

Bushbrown Mycalesis perseus 3

6 Common Castor Ariadne merione 2 7 Chocolate Pansy Junonia iphita 10 L. Gumti River Site-2 0.1275 1 Common Grass


2 Common Albatross Appias albino 10 3 Tawny Coster Acraea violae 3 4 Common Castor Ariadne merione 3 M. Gumti River Site-3 0.0746 1 Common Grass


2 Common Albatross Appias albino 3 3 Common Castor Ariadne merione 5 N Gumti River Site-4 0.4481 1 Psyche Leptosia nina 5 2 Common Mormon Papilo Polytes 8 3 Lime Butterfly Papilio demoleus 3


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S. No.


Diversity Index

4 Common Grass Yellow

Eurema hecabe 11

5 Common Pierrot Castalius rosimon 3 6 Tiny Grass Blue Zizula hylax 5 7 Plain Tiger Danaus chrysippus 2 8 Common Palmfly Elymnias

hypermnestra 3

9 Common Castor Ariadne merione 5 O. Gumti River Site-5 0.3698 1 Psyche Leptosia nina 5 2 Common Mormon Papilio polytes 6 3 Lime Butterfly Papilio dempleus 3 4 Common Grass


5 Common Emigrant Catopsilia Pomona 8 6 Common Gull Cepora nerissa 5 7 Common Crow Euploea core 2 8 Grey Pansy Junonia atlites 6 P. Gumti River Site-6 0.2445 1 Common Mormon Papilio polytes 5 2 Lime Butterfly Papilio dempleus 6 3 Common Grass


4 Common Emigrant Catopsilia Pomona 2 Mottled Emigrant Catopslia pyranthe 6 6 Common Albatross Appias albina 8 Q. Gumti River Site-7 0.4397 1 Coon Sancus fuligo 3 2 Common Mormon Papilio polytes 5 3 Lime Butterfly Papilio dempleus 6 4 Common Grass


5 Common Emigrant Catopsilia Pomona 6 6 Mottled Emigrant Catopslia pyranthe 8 7 Common Pierrot Castalius rosimon 2 8 Tiny Grass Blue Zizula hilax 5 9 Chocolate Pansy Junonia iphita 3 R. Gumti River Site-8 0.3759 1 Psyche Leptosia nina 8 2 Common Mormon Papilio polytes 3 3 Lime Butterfly Papilio dempleus 5 4 Common Grass


5 Common Emigrant Catopsilia Pomona 3 6 Mottled Emigrant Catopslia pyranthe 3 7 Common

Bushbrown Mycalesis perseus 2

8 Grey Pansy JJunonia altites 5

[Source: Ecological Survey conducted by CED, 2017] Diversity Index

Pre-monsoon Season The highest diversity index of butterfly and moth was recorded in the Chandrapur RF 1 with diversity index value of 1.0686. This is followed by


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Radhakishorepur RF (0.8608), Garjee RF (0.8052), Rubber Plantation-1 (0.4578), Gomti River Site-4 (0.4481), Gomti River Site-7 (0.4397), etc. Post-monsoon Season The highest diversity index of butterfly and moth was recorded in the Chandrapur RF 1 with diversity index value of 2.3437. This is followed by Gargee RF (1.0169), Chandrapur RF 2 (0.4398), Rubber Plantation-1 (0.3021), Agricultural land 2 (0.2981), Gomti River Site-5 (0.2081), etc. Thediversity index is presented in following table.

Table 3.23 Diversity Index of Butterfly and Moth

Sl. No. Habitats Diversity Index- Premonsoon

Diversity Index- Postmonsoon

1 Chandrapur RF 1 1.0686 2.3437 2 Radhakishorepur RF 0.8608 0.0799 3 Chandrapur RF 2 0.2681 0.4398 4 Gargee RF 0.8052 1.0169 5 Rubber Plantation-1 0.4578 0.3021 6 Rubber Plantation-2 0.1365 0.1365 7 Agricultural Land-1 0.1525 0.0302 8 Agricultural Land-2 0.2497 0.2981 9 Homestead Plantation-1 0.0737 0.186 10 Homestead Plantation-2 0.1275 0.1231 11 Gomti River Site-1 0.3186 0.1231 12 Gomti River Site-2 0.1275 0.0733 13 Gomti River Site-3 0.0746 0.0737 14 Gomti River Site-4 0.4481 0.1775 15 Gomti River Site-5 0.3698 0.2081 16 Gomti River Site-6 0.2445 0.1479 17 Gomti River Site-7 0.4397 0.1547 18 Gomti River Site-8 0.3759 0.1836

[Source: Ecological Survey conducted by CED, 2017] Amphibians

A total of five species of amphibians are reported from the study area. None of the species bear any conservational significance. Seven species viz. Duttaphrynus melanostictus, Hoplobatrachus tigerinus and Fejervarya limnocharis were recorded during the primary survey. The details of the species are given in Table 3.24.

Table 3.24 Amphibians observed/reported from the Study Area

S. No.

Common Name Scientific Name IUCN Status

WLPA, 1972 Schedule

1 India toad* Duttaphrynus melanostictus Sehneider LC IV 2 Ornate

Microhylid* Microhyla ornata Dumeril & Biborn LC IV

3 Painted Frog Kaloula pulchra Gray LC IV 4 Skipping Frog Euphlyctis ehrenbergii Peters LC IV 5 Cricket Frog* Fejervarya limnocharis Gravenhorst LC IV 6 Jerdon’s Bull

Frog Hoplobatrachus crassus Jordan LC IV


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S. No.


WLPA, 1972 Schedule

7 Indian Bull Frog* Hoplobatrachus tigerinus Daudin LC IV

Notes: PS- Primary survey by CED 2017; CC-Community Consultation; Schedule – V (Indian Wildlife Protection Act -1972); LC-Least Concern, (IUCN Version 2017.1)

Reptiles

A total of eleven (11) species of reptiles were reported/recorded from the study area. Two Schedule I species viz. Tucktoo and Bengal Monitor Lizard are reported from the study area. During the primary survey two reptile species viz. Calotes versicolor and Mabuya carinata and were recorded. The details of reptiles are given in Table 3.25.

Table 3.25 Reptiles observed/reported from the Study Area

S. No.


WLPA, 1972 Schedule

1 South Asian Wolf Gecko Hemidactylus frematus Schkgel

NE NE

2 Tucktoo Lizard* Gekko gecko Linn NE NE 3 Snake Skink Riopa albopuntalnGray NE IV 4 Common Wolf Snake Lycodon aulicus

aulicusSmith NE IV

5 Buff striped keelback Amphiesma stolatum Lima NE IV 6 Indo Gangetic Flatshell

Turtle* Lissemys punctata Webb LC I

7 Common India Monitor Lizard*

Varanus bengalensis Dandia

LC I

8 Water Monitor* Varanus salvator Laurenti LC I 9 Mabuya* Mabuiya

multifasciathKuhl NE NE

10 Garden Lizard* Calotes versicolor Daudin NE NE 11. Blind Snake* Typhlops sp. NE IV

Notes: PS- Primary survey by CED 2017; CC-Community Consultation; FD-Presence verified with Forest Department; Schedule – I, II (Indian Wildlife Protection Act -1972); LC-Least Concern, (IUCN Version 2017.1)

Avifauna

A total of 50 species of birds were recorded from the study areas during the primary survey. One Schedule I species was recorded from the study area viz. Black Kite (Milvus migrans). No IUCN Threatened species (Version 2017-1) was observed during the primary survey. Identified avifaunal species from the study area is provided in Table 3.26.

Table 3.26 Avifaunal Species observed in the Study Area

Sl. No Scientific Name Common Name Wildlife Schedule

IUCN Category

1 Acridotheres fuscus Jungle Myna IV LC 2 Acridotheres tristis Indian Myna IV LC


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IUCN Category

3 Alcedo atthis Small Blue Kingfisher IV LC 4 Anastomus oscitans Asian Openbill IV LC 5 Ardeola grayi Pond Heron IV LC 6 Bubulcus ibis Cattle Egret IV LC 7 Cacomantis merulinus Plaintive Cuckoo IV LC 8 Centropus sinensis Crow-Pheasant IV LC 9 Chrysocolaptes lucidus Greater Goldenback IV LC

10 Columba livia Common Pigeon IV LC 11 Copsychus saularis Oriental Magpie Robin IV LC 12 Coracina macei Large Cuckoo Shrike IV LC

13 Corvus (macrorhynchos) levaillantii Eastern Jungle Crow IV LC

14 Corvus splendens House Crow IV LC 15 Cuculus macropterus Indian Cuckoo IV LC 16 Cypsiurus balasinensis Asian Palm Swift IV LC 17 Dendrocitta vagabunda Rufous Treepie IV LC

18 Dendrocopos macei Fulvus Breasted Woodpecker IV LC

19 Dicaeum agile Thick-billed Flowerpecker IV LC 20 Dicaeum erythrorhynchos Pale-billed Flower Pecker IV LC 21 Dicrurus hottentottus Spangled Drongo IV LC 22 Dicrurus macrocercus Black Drongo IV LC

23 Dicrurus paradiseus Greater Racket Tailed Drongo IV LC

24 Dinopium benghalense Golden backed Woodpecker IV LC

25 Eudynamys scolopacea Asian Koel IV LC 26 Gracupica contra Asian Pied Starling IV LC

27 Halcyon smyrnensis White Throated Kingfisher IV LC

28 Ixobrychus cinnamomeus Cinnamon Bittern IV LC 29 Megalaima lineata Lineated Barbet IV LC 30 Merops orientalis Small Green Bee-eater IV LC

31 Milvus migrans Black Kite I LC

32 Motacilla alba White Wagtail IV LC

33 Motacilla caspica Grey Wagtail IV LC

34 Nectarinia asiatica Purple Sunbird IV LC

35 Oriolus xanthornus Black Hooded Oriole IV LC

36 Orthotomus sutorius Common Tailor Bird IV LC

37 Passer domestica House sparrow IV LC

38 Pelargopsis capensis Stork Billed Kingfisher IV LC

39 Picus canus Grey Headed Woodpecker IV LC

40 Psittacula alexandri Red Breasted Parakeet IV LC

41 Pycnonotus (melanicterus) flaviventris Black Crested Bulbul IV LC

42 Pycnonotus cafer Redvented Bulbul IV LC

43 Streptopelia chinensis Spotted Dove IV LC

44 Streptopelia decaocto Eurasian Collared Dove IV LC

45 Sturnus contra Pied Myna IV LC

46 Sturnus malabaricus Chestnut Headed Starling IV LC


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IUCN Category

47 Terpsiphone paradise Asian Paradise Flycatcher IV LC

48 Treron phoenicopterus Yellow Footed Green Pigeon IV LC

49 Turdoides caudatus Common Babbler IV LC

50 Vanellus indicus Red wattled Lapwing IV LC Notes: PS- Primary survey by CED 2017l; CC-Community Consultation; Schedule – IV (Indian Wildlife Protection Act -1972); LC-Least Concern, (IUCN Version 2017.1)

Mammals

Mammals within the study area are represented by 11 species. Six Schedule II mammalian species were reported from the study area. One IUCN Threatened species Stump Tailed Macaque and Sloth Bear (IUCN Vulnerable: 2017-1) was reported/recorded from the study area. The checklist of mammals reported/recorded in the study area is given in the Table 3.27.

Table 3.27 Mammalian species recorded/reported in the study area

Sl. No

Scientific Name Common Name Source Wildlife Schedule

IUCN Category

1. Canis aureus Jackal FD+CC+PS II LC

2. Felis chaus Jungle Cat CC+PS II LC

3. Herpestes edwardsi Common Mongoose

CC+PS II LC

4. Hystrix indica Indian Porcupine FD+CC IV LC

5. Lepus nigricollis Indian Hare FD+CC+PS IV LC

6. Macaca mulata Rhesus Macaque FD+CC+PS II LC

7. Macaca arctoides Stump tailed Macaque

FD+CC+PS II VU

8. Paradoxurus hermaphroditus

Common Palm Civet

FD+CC II LC

9. Pteropus giganteus Indian Flying Fox FD+CC+PS IV LC

10. Rattus rattus Common House Rat

CC+PS - LC

11. Sus scrofa Indian Wild Boar FD+CC LC Notes: PS- Primary survey by ERM during 5-7 April; CC-Community Consultation; Schedule – V (Indian Wildlife Protection Act -1972); VU-Vulnerable; LC-Least Concern, (IUCN Version 2017.1)

3.3.5 Aquatic Ecosystem

Aquatic Habitat

There are numerous rivers and streams in Tripura which support a rich diversity of inland wetland habitats. According to the National Wetland Atlas, Tripura there are 432 Wetlands in Tripura covering an area of 14559 ha. These wetlands vary in size from 2.5 ha. and above. All these wetlands falls in following 6 (six) categories- Lakes/ponds, Oxbow lakes, Waterlogged (seasonal), Reservoirs, Tanks. Besides the above wetlands, there are large numbers of water harvesting structures in different Forest Divisions which


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also qualify as wetland areas. These wetlands also support diverse birds and fish species. Following aquatic ecological groups has been studied. Macrophytes

Aquatic vegetations are observed in the banks of Gumti River, ponds, tank/pond wetland types. The most dominant macrophytes are Azolla pinnata, Eichhornia crassipes, Ipomea aquatica, Lemna minor, Najas graminea, Pistia stratiotes, Salvinia natans, Trapa natans, Typha angustifolia, and Vallisneria spiralis. Plankton

The major components of Zooplankton in freshwater ecosystem of Tripura are Cladocera,Copepoda, Ostracods and Rotifers. Earlier records indicate that nearly 50% of Cladocera species from Tripura (49 species) can be located in Udaipur and surrounding area. These include 03 species of Siddidae, 04 species of Daphnidae, 01 species of Moinidae, 02 species of Macrothricidae, 14 species of Chydoridae, Besides Cladocera and Copepods Ostracods represented by 04 species, whereas Rotifers appears to the most rare with only 03 species out of 29 species recorded from the State (Venkataraman, et.al., 2002). The Zooplankton fauna of Udaipur and adjacent region, as per earlier record include a total of 25 species out of 49 from the State of Tripura; it is composed of 08 species of cladocera, 04 species of Ostracoda, 03 species of Rotifer Primary Survey

Planktons are microscopic life forms belonging to either phytoplankton (algae) or zooplankton (protozoa, rotifers, etc.) categories. They form the lowest trophic level of the aquatic ecosystem and their presence or absence indicates the health of freshwater aquatic ecosystems. Planktons were collected from Gumti River upstream (BM-1), Gumti River upstream (BM-2) Gumti River down-stream (BM-3), Gumti River down-stream (BM-4), Gumti River down-stream (BM-5), Gumti River down-stream (BM-6) and Gumti River down-stream (BM-8). Pre-monsoon Season The planktonic diversity studies reveal that 12 species of phytoplankton and 15 species of zooplanktons were recorded from the fresh water bodies, which are commonly found in these types of water bodies. The phytoplanktonic diversity index result shows that the highest diversity is recorded in the BM-3 (2.3091); this is followed by BM-8 (2.2716), BM-4 (2.2549), BM-5 (2.1833), BM-6 (2.1415), BM-7 (1.8947), BM-2 (1.8083) and BM-1 (1.5156). The zooplanktonic diversity index result shows that the highest diversity is recorded in the BM-8 (2.2874) and this followed by BM-3 (2.2823), BM-4 (2.2228), BM-6 (2.1332), BM-7(2.0435), BM-5 (1.8360), BM-1 (0.6765) and BM-2 (0.4811).


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. Post-monsoon Season The phytoplanktonic diversity index result shows that the highest diversity is recorded in the BM-4 (1.4141); this is followed by BM-7 (1.2798), BM-1 (1.0347), BM-2 (1.0102), BM-4 (0.9557), BM-5 (0.9466), BM-3 (0.8676) and BM-6 (0.5524). The zooplanktonic diversity index result shows that the highest diversity is recorded in the BM-7 (1.7481) and this followed by BM-4 (1.3321), BM-8 (1.2770), BM-1 (1.2730), BM-5 (1.2441), BM-6 (1.0986), BM-3 (0.6365) and BM-2 (0.4811).

Table 3.28 Planktonic Diversity Index in the Study Area

Monitoring Location Phytoplanktonic Diversity Index Zooplanktonic Diversity Index Pre-monsoon Post-monsoon Pre-monsoon Post-monsoon

BM-1 1.5156 1.0347 0.6765 1.2730 BM-2 1.8083 1.0102 0.4811 0.4811 BM-3 2.3091 0.8676 2.2823 0.6365 BM-4 2.2549 0.9557 2.2228 1.3321 BM-5 2.1833 0.9466 1.8360 1.2441 BM-6 2.1415 0.5524 2.1332 1.0986 BM-7 1.8947 1.2798 2.0435 1.7481 BM-8 2.2716 1.4140 2.2874 1.2770

Benthos:

Crustean Decapod has been recorded in the past with 09 total species while molluscan fauna in the benthos included gastropoda [10 spp]. Aquatic Coleoptra Dysticidae is represented by 08 species. Fishes & Fisheries

Fish is widely available in the still (Bills / Ponds) and flowing water bodies (Rivers/Nalas), reservoir of this region. Freshwater fish species in the wetlands of Tripura has been well represented. The Working Plan for Sadar Forest Division for the period 2013-2014 to 2022-23 (Das and Barman, 2013) listed 52 species of fishes from the State of Tripura but a totalof 129 fishes have been recorded by the ZSI (Barman 2002) Barman (1988) provided a comprehensive account of Fishes of Gomti River, totally 80 species under 57genera. The fishes of Gomti River appear to represent 62% of the total fish species recorded in Tripura (Barman, 1998). It totals at 129 species under 78 genera. Atleast 07 species are endemic to India and three species are endemic to NE India. One specie Barilus nelsoni. Barman 1989, was described by RP Barman from Gumti River, Udaipur area; it has also been collected from Muhuri River in South Tripura; so this species seems to have a very limited distribution in South Tripura with Type locality in Gumti River (Barman 1969, 1998). Endemic Fish Species recorded from Tripura & North East India are as follows:


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* 1. Barilus nelsoni Barman 2. Clupisoma Montana Hora 3. Lepidouphalus annandeli Chowdhuri 4. Olyra Kempi Chaudhuri (*Endemic to South Tripura)

Primary Survey: The following species were recorded during the present survey from Gumti River are as follows:

1. Notopterus notopterus (Pallas) 2. Chela (Chela) laubuca (Hamilton) 3. Danio sp. 4. Rasbora daniconius daniconius (Hamilton) 5. Barilius barna (Hamilton) 6. Cyprinus carpio carpio Linnaeus 7. Puntius chola (Hamilton) 8. Labeo bata (Hamilton) 9. Labeo robita (Hamilton) 10. Tor tor (Hamilton) 11. Rita rita (Hamilton) 12. Ompok pabda (Hamilton) 13. Clarias batrachusLinn

3.3.6 Agricultural Diversity

People in the study area are dependent on agriculture for livelihood. The terrain of Tripura consists of undulating lands with hills and valleys. Most of the rice cultivation takes place in valleys. Jhum cultivation is also practiced in the area. Rice is grown mainly as mono crop or double crop with inter-cropping like areca nut, banana, pineapple, potato, etc. Fruits like banana, pineapple, jackfruits, guava and citrus are also produced in the area.

3.4 SOCIO-ECONOMIC ENVIRONMENT

3.4.1 Methodology for Socio-economic Study

Study Area

The study area divided into core zone (2.0 km around the plant) and buffer zone (2-10 km radius area around the plant).

Core zone: A distance of 2.0 km radius from the project boundary has been considered as the core zone based on the assumption that the magnitude of socio-economic impacts is likely to be more visible than the remaining portion of the study area; and Buffer zone: An area from 2 km radius to 10 km radius is considered as the buffer zone based on the assumption that the magnitude of socio-economic impacts is likely to be limited.


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Review of Secondary Information

A review and assessment of the available secondary data and information for the study area was undertaken in order to identify socio-economic parameters and trends that allowed for a comparative assessment of the study area vis-à-vis the block and district level socio-economic baseline assessment. Stakeholder Consultation

The stakeholder mapping and its analysis was conducted with the objective of identifying each stakeholder group; studying their profile, characteristics and the nature of their stakes; gauging their influence on the project; and understanding the specific issues, concerns as well as expectations of each group from the project. Key groups of stakeholders who were consulted during the study process were local community (including fishing communities), representatives of OTPC, NGOs, SHGs, Community Based Organizations (CBOs), representatives of the Panchayati Raj Institutions (PRI), Government officials etc.

3.4.2 Administrative Setup

There are total 28 villages, 3 census towns and 1 Nagar Parisad (Udaipur) located within the 10 km radius of the OTPC plant area. The location details of these villages are provided in Table 3.29

Table 3.29 List of the Villages Located Within the 10 km Study Area

District Block/ Nagar Parisad No of Village/ Census Town (CT) Gomati Kakraban 17 Villages Matabari 11 Villages 3 CT Udaipur 1 Nagar Parisad

The core area includes mainly three villages i.e. Kakraban, Dhudhpuskarini and Palatana. The location details of these core area villages are provided in Table 3.30

Table 3.30 List of the Villages Located Within the Area of Impact

District RD Block Census Village Distance from Proposed Project

Site (km)

Direction from Proposed Project

Site

Gomti District Kakraban Dhudhpuskarini 0.40 km East

Palatana 0.91 North Kakraban 1.78 km West

The buffer zone includes 29 habitations (25 villages, 3 census town and Udaypur Nagar Parisad).


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3.4.3 General Socioeconomic Profile

The demographic profile in terms of total population, household size and sex-ratio of the above mentioned selected villages in the block has been summarized in the sections below. Population and Household Size

As per the 2011 Census records, the study area, covering 28 villages, 3 census towns and 1 nagar parishads has a total of 41,194 households and a population of 170,326. Majority of the population in the study area falls in the rural category. Out of the 3 villages in the core study area in the Kakraban block, Palatana (6,932) has the highest population living in 1,603 household and the lowest population were recorded in Dudhpushkarini (5,121) and total household no of 1,203. The household size of above mentioned 3 villages generally ranged within 4.13 to 4.32 with an average household size of 4.23. In buffer area villages located in 10 km periphery of the study area, Udaipur Nagar Parisad (32,758) has highest population living in 8,530 household and the lowest populations were recorded in Balupathar village (466) with total household no of 100. The household size of above mentioned buffer area villages has an average household size of 4.12. Population and number of household in these villages are summarized in the Table 3.31 below. The population profile of all selected villages is given in Annex 3.6. Sex Ratio

3 villages in the core study area in the Kakraban RD block, Kakraban (960) has the highest sex ratio, Palatana (914) has the lowest sex ratio and the average sex ratio is 936 which is lower than the sex ratio of Tripura (960) and country average (943). However, the average sex ratio recorded in buffer area villages is 962 which is slightly higher than sex ratio of Tripura. Detail is given in Annex 3.7.


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Figure 3.28 Distribution of Male and Female Population in Core and Buffer Area

Table 3.31 Demographic Profile of the Villages Located within the Area of Influence

Vill

age

No.

of

Hou

seho

ld

Tota

l Pop

ulat

ion

Hou

seho

ld S

ize

Mal

e Po

pula

tion

(%)

Fem

ale

Popu

latio

n (%

)

Sex

Rat

io

SC P

opul

atio

n (%

)

ST P

opul

atio

n (%

)

Lite

rate

(%)

Mal

e Li

tera

te

(%)

Fem

ale

Lite

rate

(%

)

Core Area Palatana 1603 6932 4.32 52.24 47.76 914 41.86 0.03 90.23 93.96 86.13 Dudhpushkarani 1203 5121 4.26 51.73 48.27 933 41.91 0.08 88.94 93.97 83.46 Kakraban 2124 8774 4.13 51.03 48.97 960 34.94 0.24 91.47 94.86 87.91 Buffer Area Buffer Area Villages

36264 149499 4.12 50.97 49.03 962 23.11 12.69 90.20 93.56 86.72

[Source: Census of India 2011] Scheduled Caste (SC) & Scheduled Tribes (ST)

The overall demographic data of all the study area villages shows that the ST population in these villages is very less but SC population is quite high. The average ST and SC population is 12.69% and 23.11% respectively in villages located within the 10 km of the study area Among the 3 core area villages of the study area average ST and SC population were 0.12% and 39.57% respectively. Details of SC and ST population are given in Annex 3.6.


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Figure 3.29 Proportion of SC/ST Population in the Study Area

Source: Census 2011

Education & Literacy

The education and literacy profile in the region is relevant in order to have an understanding whether the proposed project can utilize skilled human resources available within the area. According to 2011 census data, the literacy rate in Gomti district is 84.53% which is lower than the State literacy rate of Tripura (87.2%)the average literacy rate of the core area villages is 90.21% which is higher than the State literacy rate. The highest literacy rate is observed in Kakraban (91.47%) and the lowest in Dudhpushkarini (88.94%). Average male and female literacy rate in the core area is 94.26% and 85.82% respectively and both are higher than the State average. The average male and female literacy is 93.56% and 86.72% respectively in villages located within the buffer area. Details are given in Annex 3.7.


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Figure 3.30 Sex Wise Literacy Rate in Core and Buffer area

Economic Activity & Livelihood Pattern

The relevance of economic activity and livelihood pattern is important in the context of the study since depending on the existing situation one can predict the impact of the project activity on the economy of the region. The total working population in the study area villages varies from 35.69% to 40.35%. Of the total workforce, Kakraban revealed the highest percentage of workforce with 40.35% workers while Palatana revealed the lowest workforce percentage (35.69%). Summary of work force participation in different selected villages is mentioned in Table 3.32 below. Village wise details are incorporated in Annex 3.7.

Table 3.32 Livelihood Profile in the Project Area

village/town Total Working Population

Working Population male

Working Population

female

WPR

Core Area Palatana 2474 293 35.69 Dudhpuskarini 1857 262 36.26 Kakraban 3540 853 40.35

Buffer Area Buffer Area Villages 56815 43782 13033 38.00

It can be seen from the following figures that the study area is characterised by dominance of main worker who are involved in same work more than 6 month in a year. It can be also observed that farm based and non-farm based livelihoods, both as the primary and secondary sources of livelihood. The agriculture based


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livelihoods comprise of 40.36% of the work force and the non-agriculture based livelihoods comprises of 57.55% of the work force. In farm based livelihood people are mostly involved as cultivator and agricultural labour while in case of nonfarm based livelihood community depends on rubber and allied production activity. Majority population in the study area villages are either involved in agricultural crop cultivation or involved in horticulture both at individual level as well as community level. Study area mainly comprises of mono cropped plane land. Paddy is the major agricultural produce (810673 MT production in 2017-18). Apart from that, inhabitants of study area villages are also involved in Wheat, Sugar cane, Cotton, Jute, Pulse, Oil seeds and Potato cultivation in their agricultural land. People also earn their livelihood by producing Pineapple, Jackfruit, Banana, orange etc at individual level or at community level. Large number of the people in Tripura are also involved in rubber plantation for their livelihood as rubber is the main cash crop in this area. Total rubber plantation area in the state is 11,740.42 ha and tapping area of rubber is 1.22 lakh ha. Total rubber production in the state in the year 2017-18 was 20,000 MT.


135

Figure 3.31 Worker Profiles with in Study Area

3.4.4 Basic Amenities and Infrastructure

Drinking Water facilities

The Census data reveals that drinking water facility exits in all the villages. There are different types of drinking water facility available in study area. Accelerated Rural Water Supply (ARWS scheme) is the major source of water. Under this scheme drinking water facilities are installed at Panchayet level or ADC level and it supplies water through pipeline to approx. 60% of villagers in this panchayat. As in general iron content in ground water is high in Tripura, one Iron filtration unit is also provided in ARWS scheme. Other than ARWS, in plane land people collect drinking water from tube well, earthen ring well or from mini deep tube well installed by local administration. But in hilly terrain where ground water level is much lower than the plane land, people suffer a lot


136

for drinking water. They depend on mini deep tube well installed by local administration or tanker supply by Panchayat or ADC. People also depends on the above mention sources for their daily water need for other activities. Villages where river or stream are present, people also use water from these sources this for their domestic purpose. Other than river or stream, surface water bodies in the villages are very less in number. Medical Facilities

Medical facilities are one of the basic service indicators which need to be studied so as to know the quality of life in the area. In the 29 study area villages considered for the study, all villages have health sub center at panchayat or ADC level. Rural hospital is present only at Palatana. Other than that villagers have to go to Udaipur to avail the medical facility. Educational Facilities

The study area possesses necessary educational infrastructure to cater to the educational needs of the both rural and urban population. In the study area one junior basic School and one senior basic school is present in every panchayet and ADC. There are some of Panchayat and ADC where more than one JB school is present. ICDS is present in all the villages. For higher education students have to go to the nearest town. Transport & Communication

Shilong-Agartala-Sabroom National Highway and Udaipur -Kakraban State Highway are the major road connecting the study area with Agartala and are being used by the local people as a route of transportation. There are also some major district road which connect the study area with nearest town. Pucca paved road is present in almost every village. The public transport system is yet to reach its highest efficacy however there is public bus transport system present in some of the core area villages. Other than that villagers depend on the private auto or jeep. The post office facility is available within 5 to 10 km from all study area villages. Market Facilities

The study on availability of market place not only tells the buying power of the common people but also gives an inner sight of services it provides for the attainment of a better living. Market facility is present in Kakraban. Other than the local market large market place is present in Udaipur. There are only some basic amenities shops present with each village. Power Supply

Electricity is available in all study area villages through a stable 220V electricity supply adequate for domestic, agricultural and other purposes.


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Post and Telecommunication

In this era of telecommunication, access to mobile phone is within every bodies reach. All villages from sample study area have the access to telecommunication, post- office and other private courier services. Festivals

Since Hinduism is predominant in this region, common festivals of Hindu s like Holi, Rath yatra, Durga puja, Kali puja, Diwali are quite common. Apart from these, many tribal festivals such as Kharchi Puja, Ker Festival, Garia Puja, Ganga Puja are celebrated in this region.

3.4.5 Cultural and Historical Sites

There are no designated archaeological sites within study area. As is typical of rural India settlements, each village in the study area has some cultural sites or sites of religious significance, like temples, mosques, graveyards etc. Some of them are of significance for the community. Sometimes their significance is related to specific seasons/or time of the year.


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4 IMPACT ASSESSMENT AND MITIGATION MEASURES

This section identifies and assesses the potential impacts in the environment that can be expected from the proposed OTPC expansion project at Palatana in Gomati District, Tripura. The impacts due to the Project activities across different phases have been identified and assessed. The Project activities will impact the environment in two distinct phases: a. Construction b. Operation Impacts are identified and predicted based on the analysis of the information collected from the following:

Project information (as outlined in Section 2); Baseline information (as outlined in Section 3).

The identification of likely impacts during construction and operation phases has been carried out based on likely activities having their impact on environmental and socio-economic parameters. The details of the activities and their impacts have been worked out in the following sections. The next section discusses in detail the impact assessment methodology adopted as part of EIA process for the proposed OTPC-Palatana expansion project.

4.1 IMPACT ASSESSMENT METHODOLOGY AND APPROACH

Impact identification and assessment starts with scoping and continues through the remainder of the impact assessment process (IAP). The principal impact assessment (IA) steps are summarized in Figure 4.1 and comprise:

Impact prediction: to determine what could potentially happen to resources/receptors as a consequence of the Project and its associated activities. Impact evaluation: to evaluate the significance of the predicted impacts by considering their magnitude and likelihood of occurrence, and the sensitivity, value and/or importance of the affected resource/receptor. Mitigation and enhancement: to identify appropriate and justified measures to mitigate negative impacts and enhance positive impacts. Residual impact evaluation: to evaluate the significance of impacts assuming effective implementation of mitigation and enhancement


139

Figure 4.1 Impact Assessment Process

Prediction of Impacts

Prediction of impacts is essentially an objective exercise to determine what could potentially happen to the environment as a consequence of the project and its associated activities. This is essentially a repeat of the process undertaken in scoping, whereby the potential interactions between the project and the baseline environment are identified. From these potential interactions, the potential impacts to the various resources/receptors are identified, and are elaborated to the extent possible. The diverse range of potential impacts considered in the IA process typically results in a wide range of prediction methods being used including quantitative, semi-quantitative and qualitative techniques. The nature and types of impacts that has been addressed in this EIA is defined in the Box 4.1 below.

Box 4.1 Nature and types impacts considered for impact assessment

Evaluation of Impacts

In assessing the significance of impact, the following impact characteristics are taken into consideration:

Negative, when impact is considered to represent adverse change from the baseline or to have introduced a new undesirable factor; and Positive or beneficial, when impact is considered to represent improvement to baseline or to have introduced a new desirable factor. Direct, impacts that result from a direct interaction between the project and a resource/ receptor Indirect, impacts that follow on from the direct interactions between the project and its environment as a result of subsequent interactions within the environment; and Induced, impacts that result from other activities (which are not part of the project) that happen as a consequence of the project


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Determining Magnitude of an impact

Magnitude, i.e. severity of an impact or degree of change caused by a project activity is a function of one or more of the following characteristics:

Scale: Degree of damage that may be caused to the environmental components concerned. Extent: The extent refers to spatial or geographical extent of impact due to proposed project and related activities. Duration: The temporal scale of the impact in terms of how long it is expected to last.

Criteria have been defined for each of these key elements and classified based on the level of impacts (low, medium and high) on the environmental component, presented in Table 4.1 below:

Table 4.1 Magnitude Prediction Criteria

Impact Elements

Criteria Ranking

Scale Irreversible damage to natural environment and/or difficult or may not to revert back to earlier stage with mitigation; Major changes in comparison to baseline conditions and / or likely to regularly or continually exceed the standard;

High

Reversible damage to natural environment but likely to easily revert back to earlier stage with mitigation; Perceptible change from baseline conditions but well within acceptable norms.

Medium

Effect is within the normal range of natural variation; No perceptible or readily measurable change from baseline conditions;

Low

Extent Project site and the entire study area (10 km from OTPC Palatana plant site)

National

Project site & its immediate vicinity (2.0 km from OTPC Palatana plant site)

Regional

Project site & its immediate vicinity (0.5 km from OTPC Palatana plant site)

Local

Duration Spread beyond the lifecycle of the project Long term Spread across several phases of the project lifecycle Medium

term Only during particular activities or phase of the project lifecycle

Short term

Magnitude essentially describes the intensity of the change that is predicted to occur in the resource/receptor as a result of the impact. The magnitude combines the impact characteristics of Extent, Duration and Scale and is a multiplicative factor of these three criteria set. Based on the above understanding magnitude of impact is assessed as per the Table 4.2.

Table 4.2 Assessing Magnitude of Impact

Extent Duration Scale Magnitude Local Short Term Low Negligible Regional Short Term Low Small


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Extent Duration Scale Magnitude Local Medium term Low Small Local Short Term Medium Small National Short Term Low Small Local Long term Low Small Local Short Term High Small Regional Medium term Low Small Regional Short Term Medium Small Local Medium term Medium Small National Medium term Low Medium National Short Term Medium Medium Regional Long term Low Medium Regional Short Term High Medium Local Long term Medium Medium Local Medium term High Medium Regional Medium term Medium Medium National Long term Low Medium National Short Term High Medium Local Long term High Medium National Medium term Medium Large Regional Long term Medium Large Regional Medium term High Large National Long term Medium Large National Medium term High Large Regional Long term High Large National Long term High Large

Determining Sensitivity/ Importance/ Vulnerability of Receptor

In addition to characterising the magnitude of impact, the other principal step necessary to assign significance for an impact is to define the sensitivity/ vulnerability/ importance of the impacted resources/ receptor. There are a range of factors to be taken into account when defining the sensitivity/ vulnerability/ importance of the resource/ receptor, which may be phisical, biological, cultural or human as per the following understanding:

Where the resource is physical (for example, fresh water body) its quality, sensitivity to change and importance (on a local, regional, national importance) are considered. Where the resources/ receptor is biological or cultural (for example, wildlife habitat), its importance (for example local, regional or national importance) and its sensitivity to the specific type of impact are considered. Where the receptor is human, the vulnerability of the individual, community or wider societal group is considered.

Definition as defined in Table 4.3 has been adopted to determine sensitivity/ importance/ vulnerability of environmental resources or receptor.


142

Table 4.3 Sensitivity/Importance/ Vulnerability Criteria

Sensitivity Criteria Contributing Criteria High Existing physical environment quality is already under stress;

Ecologically sensitive/ protected area, provides habitat for globally protected species; Profound or multiple levels of vulnerability that undermine the ability to adapt to changes brought by the project. Human receptors/ vulnerable community are located within the project footprint and directly affected by the project

Medium Existing physical environment quality shows some sign of stress; which is sensitive to change in quality or physical disturbance; Natural habitat provides habitat for wildlife, which are protected under National regulations; Some, but few areas of vulnerability; still retaining an ability to at least in part adapt to change brought by the project. Human receptors/ vulnerable community are located adjacent the project site and likely to be affected by the project

Low Existing physical environment quality is good; Modified habitat provides habitat for common species; Human receptors are located away and are not likely to be affected due to the project related activities

Evaluating Significance of Impacts

Once magnitude of impact and sensitivity/ vulnerability/ importance of resource/ receptor have been characterised, the significance was assigned for each impact. Impact significance is designated using the matrix shown in Figure 4.2

Figure 4.2 Assessing Significance of Impact due to Proposed Project

The matrix applies universally to all resources/receptors, and all impacts to these resources/receptors, as the resource/receptor-specific considerations are factored into the assignment of magnitude and sensitivity/vulnerability/ importance designations that enter into the matrix Box 4.2 provides a context for what the various impact significance ratings signify.

Sensitivity/Vulnerability/ Important Resource/Receptor Low Medium High

Mag

nitu

de o

f Im

pact

Small Negligible

Minor

Moderate

Medium Minor

Moderate

Major

Large Moderate

Major

Major


143

Box 4.2 Context of Impact Significance

Identification of Mitigation and Enhancement Measures

Once the significance of an impact has been characterised, the next step is to evaluate what mitigation and enhancement measures are warranted. For the purposes of this IA, ERM has adopted the following Mitigation Hierarchy:

Avoid at Source; Reduce at Source: avoiding or reducing at source through the design of the project. Abate on Site: add something to the design to abate the impact. Abate at Receptor: if an impact cannot be abated on-site then control measures can be implemented off-site. Repair or Remedy: some impacts involve unavoidable damage to a resource and these impacts can be addressed through repair, restoration or reinstatement measures. Compensate in Kind, compensate through other means: where other mitigation approaches are not possible or fully effective, then compensation for loss, damage and disturbance might be appropriate.

The priority in mitigation is to first apply mitigation measures to the source of the impact (i.e., to avoid or reduce the magnitude of the impact from the associated Project activity), and then to address the resultant effect to the resource/receptor via abatement or compensatory measures or offsets (i.e., to reduce the significance of the effect once all reasonably practicable mitigations have been applied to reduce the impact magnitude).

An impact of negligible significance is one where a resource/receptor (including people) will essentially not be affected in any way by a particular activity or the predicted effect is deemed to be ‘imperceptible’ or is indistinguishable from natural background variations. An impact of minor significance is one where a resource/receptor will experience a noticeable effect, but the impact magnitude is sufficiently small (with or without mitigation) and/or the resource/receptor is of low sensitivity/ vulnerability/ importance. In either case, the magnitude should be well within applicable standards. An impact of moderate significance has an impact magnitude that is within applicable standards, but falls somewhere in the range from a threshold below which the impact is minor, up to a level that might be just short of breaching a legal limit. Clearly, to design an activity so that its effects only just avoid breaking a law and/or cause a major impact is not best practice. The emphasis for moderate impacts is therefore on demonstrating that the impact has been reduced to a level that is as low as reasonably practicable (ALARP). This does not necessarily mean that impacts of moderate significance have to be reduced to minor, but that moderate impacts are being managed effectively and efficiently. An impact of major significance is one where an accepted limit or standard may be exceeded, or large magnitude impacts occur to highly valued/sensitive resource/receptors. An aim of IA is to get to a position where the Project does not have any major residual impacts, certainly not ones that would endure into the long-term or extend over a large area. However, for some aspects there may be major residual impacts after all practicable mitigation options have been exhausted (i.e. ALARP has been applied). An example might be the visual impact of a facility. It is then the function of regulators and stakeholders to weigh such negative factors against the positive ones, such as employment, in coming to a decision on the Project. Identification


144

Residual Impact Evaluation

Once mitigation and enhancement measures are declared, the next step in the IA Process is to assign residual impact significance. This is essentially a repeat of the impact assessment steps discussed above, considering the assumed implementation of the additional declared mitigation and enhancement measures. Management and Monitoring

The final stage in the IA Process is definition of the management and monitoring measures that are needed to identify whether: a) impacts or their associated Project components remain in conformance with applicable standards; and b) mitigation measures are effectively addressing impacts and compensatory measures and offsets are reducing effects to the extent predicted. A Environmental Management Plan, which is a summary of all actions which the Project Proponent has committed to executing with respect to environmental/social/health performance for the Project, is also included as part of the EIA report. The Environmental Management Plan includes mitigation measures, compensatory measures and offsets and management and monitoring activities.

4.2 IDENTIFICATION OF POTENTIAL IMPACTS

The potential impacts have been identified through a systematic process whereby the activities (both planned and unplanned) associated with the Project have been considered with respect to their potential to interact with environmental and social resources or receptors. The interaction matrix enables a methodical identification of the potential interactions each Project activity may have on the range of resources/ receptors within the Area of Influence i.e. the study area for the Project.


145

Table 4.4 Impact Identification Matrix for OTPC-Palatana Expansion Project

Project Activity/ Hazards Environmental Resources Ecological Resource Social-Economic Resources

A

esth

etic

& V

isua

l Im

pact

Lan

d U

se

Soi

l/ Se

dim

ent Q

ualit

y

Air

Qua

lity

Noi

se &

Vib

ratio

n

Topo

grap

hy &

Dra

inag

e

Surf

ace

wat

er re

sour

ce

Surf

ace

wat

er q

ualit

y

Gro

und

wat

er re

sour

ce

Gro

und

wat

er q

ualit

y

Traf

fic

(Roa

d)

Ter

rest

rial

Flo

ra

Terr

estr

ial F

auna

Aqu

atic

Flo

ra &

Fau

na

Prot

ecte

d Sp

ecie

s

Job

& e

cono

mic

opp

ortu

nity

Econ

omy

& L

ivel

ihoo

ds

Com

mon

Pro

pert

y R

esou

rces

Land

Use

(Eco

nom

ic

Dis

plac

emen

t)

Infr

astr

uctu

re &

Ser

vice

s

Cul

tura

l Res

ourc

es

Com

mun

ity H

ealth

& S

afet

y

Occ

upat

iona

l hea

lth &

saf

ety

Construction Phase Site Development Construction of plant building/ sheds/ and setting up plants & machineries

Heavy equipment operation Storage & handling of construction materials

Storage, handling and disposal of construction waste

Generation of sewage and discharge Influx of construction workers Transportation of manpower, equipment & materials by road

Sourcing of construction water & domestic water

Operation Phase Stack emission from plant Noise generation due to operation of plant and auxiliaries

Sourcing of water for plant Waste water generation and discharge

Hazardous material and waste storages

Natural gas transportation by pipeline


146

Project Activity/ Hazards Environmental Resources Ecological Resource Social-Economic Resources

A

esth

etic

& V

isua

l Im

pact

Lan

d U

se

Soi

l/ Se

dim

ent Q

ualit

y

Air

Qua

lity

Noi

se &

Vib

ratio

n

Topo

grap

hy &

Dra

inag

e

Surf

ace

wat

er re

sour

ce

Surf

ace

wat

er q

ualit

y

Gro

und

wat

er re

sour

ce

Gro

und

wat

er q

ualit

y

Traf

fic

(Roa

d)

Ter

rest

rial

Flo

ra

Terr

estr

ial F

auna

Aqu

atic

Flo

ra &

Fau

na

Prot

ecte

d Sp

ecie

s

Job

& e

cono

mic

opp

ortu

nity

Econ

omy

& L

ivel

ihoo

ds

Com

mon

Pro

pert

y R

esou

rces

Land

Use

(Eco

nom

ic

Dis

plac

emen

t)

Infr

astr

uctu

re &

Ser

vice

s

Cul

tura

l Res

ourc

es

Com

mun

ity H

ealth

& S

afet

y

Occ

upat

iona

l hea

lth &

saf

ety

Vehicular movement for transportation of manpower

Generation and disposal of Hazardous waste

Storm water runoff Generation of MSW & Disposal = Represents “no” interactions is reasonably expected = Represents interactions reasonably possible but none of the outcomes will lead to significant impact = Represents interactions reasonably possible where any of the outcomes may lead to potential significant impact


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4.3 POTENTIAL IMPACT

Based on the Potential Interactions Matrix for Project activities and likely impacted resources/ receptors from construction and operational phases of the proposed Project, the potential impacts are discussed in the following sections:

4.3.1 Potential Impact Aesthetic and Visual

Construction Phase

Source of Impact: The proposed expansion unit will be constructed within the plant site. The proposed site is already developed- filling or levelling will not be required. The earmarked proposed expansion site within the plant site has no vegetation – therefore, clearance of vegetation will not be required. The sources aesthetics and visual impacts can result from: (i) storage of construction materials, (ii) storage and disposal of construction waste, (iii) labour camp and (iv) storage and disposal of municipal solid waste. Assessment of Impact: The construction materials are likely to be stored in the vacant land of the existing plant area. The construction workforce will be accommodated in the existing plant area, i.e. northern site of the plant. The disposal of construction waste and MSW from labour camp may lead to nuisance and visual impact of the nearby settlements, if disposed in non-designated area. The environmental setting of the site reveals that (Refer Section 2.3), there are no industries adjacent to the plant. The plant has boundary and greenbelt around the periphery of the plant. The nearest settlements are Dudhpuskarini (adjacent to plant towards east and south), Palatana (adjacent to plant towards north) and Kushamara (adjacent to plant towards west). There are natural forest and plantation forests in these villages. Proper management of the storage facility and labour camp may not cause any significant change in the environmental setting of the area. The duration of activity will be short term (30-33 months). The extent of impact is likely to be within 0.5 km. The potential impact on aesthetics and visual quality due to above mentioned activities is assessed to be minor. Impact Aesthetic and visual impact due to construction activity

Impact Nature Negative Positive Neutral

Impact Type Direct Indirect Induced

Impact Duration Short Term Medium Term Long Term

Impact Extent Local Regional National

Impact Scale Low Medium High

Impact Magnitude Positive Small Medium Large


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Resource/ Receptor Sensitivity

Low Medium High

Impact Significance Negligible Minor Moderate Major

Significance of impact is considered Minor

Mitigation Measures: The proposed mitigation measures are as follows:

All the construction activities will be restricted within the designated site; On completion of work all temporary structures, surplus materials and wastes will be completely removed from site and disposed for filling of low land within the plant or designated site; Construction wastes and municipal solid waste temporarily stored at the sites will be transported to the designated disposal site/facility at regular intervals.

Residual Impact: Considering the implementation of above mentioned mitigation measures, the residual impact on aesthetic and visual quality is assessed to be negligible. Operational Phase

Source of Impact: Potential aesthetics and visual impacts can result from: (i) physical presence of plant and (ii) illumination from plant. Assessment of Impact: The proposed expansion unit will be constructed within the main plant. The local people are experienced of physical presence of industries – existing units of OTPC Palatana. Physical presence of expansion unit and additional illumination may not cause major change of environmental settings of the area. This will be a permanent setup- life of the plant. The potential impact on aesthetics and visual is assessed to be minor. Impact Aesthetic and visual impact due to operational phase








Low Medium High




Development of more greenbelt along plant boundary. Appropriate shading of lights to prevent scattering.


149

Residual Impact: Considering the implementation of above mentioned mitigation measures, the residual impact on aesthetic and visual quality is assessed to be negligible.

4.3.2 Potential Impact on Ambient Air Quality

Construction Phase:

Sources of Impact: The following impacts are anticipated on air quality during construction phase of the proposed project:

Fugitive dust emission due to construction activities such as earth moving, building foundations for plant, transportation of construction materials, etc. Wind-blown dust while handling of construction materials like cement, sands, etc. Emission due to movement of vehicles, movement and operation of construction equipment.

Embedded Control Measures: The project embedded control measures are as follows:

Vehicle, equipment and machinery used for construction would conform to applicable emission norms.

Assessment of Impact: The fugitive dust related impacts will be minimal as the proposed expansion unit will be constructed within the existing plant area. The site is already developed; therefore, extensive earth work like filling levelling, top soil removal, etc., will not be required. The construction material will be stored in the covered storage area; generation of windblown dust is expected to be minimum.

The power required for construction activities will be drawn mainly from the existing grid supply; hence, the operation of DG sets will also be limited and will be used only as back-up during power failure. The operation of back up DG sets will generate the PM, NO2 and SO2. The operation of diesel driven machineries, equipment and vehicles used for transport of construction materials and manpower will also generated pollutants like PM, NO2 and SO2. The baseline air quality monitoring results shows that concentration of PM, SO2 and NO2 were well within the NAAQS indicating that the environment is not stressed (Refer Section 3.2.3). The generation of PM, SO2 and NO2 from the above mentioned activities are not expected to result in significant changes of baseline condition or exceedance of NAAQS. The duration of the construction activity will be short term (30-33 months). The fugitive emissions are likely to be dispersed locally. The potential impact on air quality is assessed to be minor. Impact Air quality impact due to construction activities





150





Low Medium High




The construction materials will be stored away from nearby human settlement. Further efforts would be made to maintain the stockpile against the wall or obstruction so that it works as a windbreak and the fugitive emissions by strong winds can be avoided; During construction, the approach /access road will be kept clean, free from mud and slurry to prevent any entrainment of dust; Waste from construction site will not be burned; All loading and unloading activities to be carried out as close as possible to the storage facilities; Proper handling of materials to ensure minimal emission of dust.

Residual Impact: Considering the implementation of above mentioned mitigation measures, the residual impact on ambient air quality is assessed to be negligible. Operational Phase

Source of Impact: The following impacts are anticipated on air quality during operational phase from the proposed project:

Emission of PM, NOx and SO2 due to operation of boiler; Embedded Control Measures: The project embedded control measures are as follows:

Use of Dry Low NOx burner. Assessment of Impact: The operation of the plant with natural gas as fuel in combined cycle will generate flue gas emissions containing NOx. Emissions of SO2 are likely to be negligible, as natural gas typically has a no sulphur level (as per the natural gas specifications for the Project). Particulate emissions are likely to be negligible (about 1.7 mg/Nm3); as natural gas is a gaseous fuel (there is no supplementary fuel to be used in the GT). Summary of Emission Sources and Emission Rates: The emission source during the operation of the Plant in combined cycle operation will be main stacks (attached to HRSG). Emissions from each stack based on the combined cycle operation along with stack parameters are presented in Table 4.5.


151

Table 4.5 Emission Parameters for the Power Plant with Natural Gas as Fuel

Stac

k

UTM* Co-ordinates* (m)

Stac

k H

eigh

t (m

)

Stac

k In

tern

al D

is (m

)

Flue

Gas

Exi

t Vel

ocity

(m

/s)

Flue

Gas

Tem

pera

ture

(°

K)

Vol

umet

ric

Flow

Rat

e (N

m3 /s

)

Emission Concentration**

Emission Rate

NOx PM10 NOx PM10

Easting Northing

mg/

Nm

3

mg/

Nm

3

(g/s

)

(g/s

)

Stack 1 340503 2599739 60 6.5 20 383 663 94 1.7 62.35 1.13 Stack 2 340502 2599774 60 6.5 20 383 663 94 1.7 62.35 1.13

* UTM Zone – 46 ** Guaranteed emissions provided by the OEM for natural gas as fuel Note: Stack parameters are as provided by OTPC. Prediction of Impacts

Impacts due to the operation of the plant were assessed by modelling projected emission rates (Table 4.5) using the AMS/EPA Regulatory Model (AERMOD). AERMOD is a modelling system consisting of three separate modules: AERMET, AERMAP and AERMOD. AERMET is a meteorological pre-processor and uses hourly surface observations, cloud cover, and upper air parameters from twice-daily vertical sampling of the atmosphere to create two output files consisting of surface and vertical profile data, respectively. The terrain pre-processor AERMAP uses DEM maps as well as user generated receptor grids. AERMAP’s output file consists of the x, y locations of each receptor, mean sea level (MSL) elevation and hill profile parameters. The hill profile parameter is used in determining plume flow around elevated terrain. Model Options: The AERMOD model was run with the following regulatory default options in this assessment:

Stack-tip downwash; Elevated terrain effects; Use of calms processing routine; Use of missing data processing routine; and No exponential decay

The area surrounding the Project site has one operational 2 x 363.3 MW CCPP of OTPC and scattered rural settlements in the surroundings. Based on this, the Project site and its surroundings have been considered as rural area, and therefore, the rural dispersion coefficient was used in the Model. Meteorological Data: The input meteorological data for the AERMOD was generated using the MM5 model, which was downscaled to fine grid data suitable for modelling. The data used in the study was site specific and was collected during study period. Terrain Data: Terrain data for the AERMAP model were taken from the 30 m SRTM database, while land cover data was sourced from satellite imagery of the Project site and its surroundings.


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Receptors: The receptor grid or network, defined the locations of predicted ground level concentrations (GLCs) used to assess compliance with the relevant standards or guidelines. The following comprehensive fine and coarse receptor network was used for this analysis:

100 m spaced receptors from the project boundary up to 10 km; and Cartesian receptors (5 nos.) located within the study area, where baseline monitoring was carried out during the study period.

This network used Cartesian (X, Y) receptors with UTM coordinates. Base elevation of all the receptors were found using terrain elevations interpolated from SRTM (~90 m) Digital Elevation Model (DEM) data. The discrete Cartesian receptor locations are shown in Error! Reference source not found. and Figure 4.3 details have been presented in Table 4.6.

Table 4.6 Monitoring Locations with respect to the Project

Sl. No.

Monitoring location

UTM Co-ordinates* (m) Distance from Plant Stacks (km)

Direction from Plant Easting Northing Elevation

1 AQ1 340792 2599693 35.88

Within Plant Boundary

-

2 AQ2 341241 2599127 30.13 0.350 SE 3 AQ3 340944 2601026 33.78 1.000 N 4 AQ4 338597 2598506 26.52 2.000 WSW 5 AQ5 347274 2601607 29.71 6.500 ENE 6 AQ6 336778 2601705 28.99 3.800 NW 7 AQ7 343093 2604093 26.02 4.700 NE 8 AQ8 341894 2595667 30.12 3.300 SSE

* UTM Zone - 46

Modelling Results

Predicted maximum ground level concentrations within the Project AOI with natural gas as fuel are presented in Table 4.7. Isopleths of ground level concentration for different averaging periods of the criteria pollutants (NOx and PM10) with natural gas as fuel are presented in Figure 4.4 to Figure 4.5. It is evident from Table 4.7 that the maximum ground level concentration (maximum baseline concentration + predicted maximum concentration) in the Project AOI with natural gas as fuel will be well within the applicable standards for air quality. The additional pollution load of PM10 and NOx from proposed expansion project may not cause major changes in the existing baseline conditions or exceed the NAAQS. The emissions from the plant will however be long term, i.e. will occur for entire life of the plant. The potential impact on air quality due to emissions from the plant is assessed to be moderate. Impact Air quality impact due to operation of plant






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Low Medium High


Significance of impact is considered Moderate

Mitigation Measures

To ensure compliance with the air emission criteria for flue gas stacks, the following measures will be implemented during operations:

The use of continuous emission monitoring (CEM) equipment for the measurement of air emission levels in the exhaust stack of HRSG. CEM will be undertaken for PM10, NOx, SO2, CO and O2; PM2.5 and VOCs will be monitored periodically, to ensure that these emissions are not occurring as a result of the incomplete burning of the natural gas fuel. The stack will be provided with safe access to sampling points for CEM.


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Figure 4.3 Receptor Network and Emission Sources


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Table 4.7 Predicted Conc. of NOx & PM at Receptors due to Proposed Project

Receptor Oxides of Nitrogen (NOx) Particulate Matter (PM10) Predicted

Concentration (μg/m3)

Avg. Background Concentration (μg/m3)

Total Concentration (Predicted + Background) (μg/m3)

Standard (μg/m3)

Predicted Concentration (μg/m3)

Avg. Background Concentration (μg/m3)

Total Concentration (Predicted + Background) (μg/m3)

Standard (μg/m3)

Max 11.25 80 0.2 100 AQ-1 0.00 24.13 24.13 0.00 66.08 66.08 AQ-2 0.00 21.01 21.01 0.00 55.33 55.33 AQ-3 2.04 22.57 24.61 0.04 61.08 61.12 AQ-4 0.24 21.65 21.89 0.00 56.96 56.96 AQ-5 0.46 22.06 22.52 0.01 55.96 55.97 AQ-6 2.78 21.51 24.29 0.05 59.17 59.22 AQ-7 4.64 21.19 25.83 0.08 55.38 55.46 AQ-8 0.00 22.06 22.06 0.00 56.50 56.5


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Figure 4.4 NOx Isopleths - 24 Hourly Maximum Ground Level Concentrations


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Figure 4.5 PM Isopleths - 24 Hourly Maximum Ground Level Concentrations

4.3.3 Green House Gas Emissions

The Kyoto Protocol – United Nations Framework Convention on Climate Change nominates the following GHGs:

Carbon dioxide (CO2); Methane (CH4); Nitrous Oxide (N2O); Hydrofluorocarbons (HFCs); and Perfluorocarbons (PFCs).


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Inventories of GHG emissions can be calculated using published emission factors. Different gases have different greenhouse warming effects (referred to as warming potentials) and emission factors take into account the global warming potentials of the gases created during combustion. Typically, greenhouse gas emissions are reported in units of carbon dioxide equivalent (CO2e). Gases are converted to CO2e by multiplying by the gas' global warming potential (GWP). The GWP of gases are as follows1:

GWP for CO2 = 1 GWP for CH4 = 21 GWP for N2O = 310

When the global warming potentials are applied to the estimated emissions then the resulting estimate is referred in terms of CO2-equivalent (CO2e) emissions. Operation of OTPC Project

GHG Estimation and Impact

The combustion of natural gas produces GHGs. The amount of GHGs emitted by a power plant is a measure of its contribution to global warming and can be estimated based on fuel consumption. In order to estimate GHG emissions, the IFC recommended Carbon Emission Estimation Tool (CEET model – Version February 2014)2 has been used as set out below.

Table 4.8 Estimated GHG Emissions from the Plant

SN Particular Value Unit Using Natural Gas as Fuel A* Net Heat Rate (Natural Gas in Combined Cycle) 7,278 KJ/KWH B* Gross Generation Capacity (Combined Cycle) 726,600 KW C Operating Days 330 days D Daily Operating Hours 24 Hours/day E Total Annual Output (= B x C x D) 5754672000 KWH F Annual Fuel Consumption (= E x A) 4.18825E+13 KJ 41,882.50 TJ G* GHG Emission Rates CO2 181.2 tCO2/TJ CH4 0.003 tCO2/TJ N2O 0.010 tCO2/TJ H Annual GHG Emission in Combined Cycle 2,389,437 tCO2e/year

* Based on natural gas specification provided by OTPC. ** Based on GHG emission factors provided in CEET

It is evident from Table 4.8 that the estimated GHG emissions from the Plant while using natural gas as primary fuel will exceed the threshold of ADB SPS (1) 1 Source: Intergovernmental Panel on Climate Change (IPCC) (1995), Second Assessment Report

2 http://www.ifc.org/wps/wcm/connect/Topics_Ext_Content/IFC_External_Corporate_Site/CB_Home/Measuring+Reporting/


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(100,000 tons CO2e per year) and of IFC PS3 (25,000 tons CO2e per year) that define them as significant GHG emission sources. Therefore, the Project is required to report annual GHG emissions. As per the latest report (December 2015) of GHG emission submitted by India to the United Nations Framework Convention on Climate Change (UNFCCC)1, electricity generation sector contribution to GHG emission in year 2010 was 1510,120.76 Gg CO2eq. The emission intensity of GDP has reduced by 12% from 2005 to 2010, on course to meeting the voluntary target of 20-25% reduction in emission intensity of GDP by 2020. Taking this into consideration, GHG emission contribution of the proposed project emission impact will be moderate. Impact GHG emissions from operation of OTPC expansion project








Low Medium High



Mitigation Measures

The following mitigation measures will minimise GHG emissions to ALARP levels:

Continuous monitoring and recording of CO2 emission from the stacks through CEMS. Ensure that all equipment and machinery is maintained in accordance with manufacturer’s specifications; Higher efficiency steam turbine blade design; and Improved efficiency of auxiliary drives.

4.3.4 Potential Impact on Noise Quality

Construction Phase

Source of Noise Pollution: The potential impacts on noise quality may arise out of the following:

Machineries & Equipment;

1 http://unfccc.int/resource/docs/natc/bgdnc2.pdf


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Vehicular Traffic; Backup DG set.


Vehicle, equipment and machinery used for construction activities would conform to applicable noise norms.

Assessment of Impact: The construction activities such as transportation of raw materials for civil works, operation of heavy equipment and construction machinery are likely to cause increase in the ambient noise levels. The ambient noise level in and around the plant was well within the ambient noise standard. The noise generated from the above mentioned activities is likely to be attenuated within 500m from the construction site. This may cause discomfort the construction workers of site and nearby receptor – Palatana and Dudhpuskarini villagers. The construction activity is a short term activity, i.e. 30-33 months. The potential impact on noise quality due to above mentioned construction activities is assessed to be minor. Impact Noise quality impact due to construction activities







Resource/ Receptor Sensitivity Low Medium High




Maintenance of vehicles and machineries to optimise the noise level; Night time construction activities will be restricted; PPE will be provided to the construction workers.

Residual Impact: Considering the implementation of above mentioned mitigation measures, the residual impact on noise quality is assessed to be negligible. Operational Phase

Sources of Impact: For gas -fired power plants, the major noise sources during base load operation are the air-cooled condenser (ACC) or cooling tower, steam turbine generator (STG), combustion inlet filter house, and the exhaust stack or


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heat recovery steam generator (HRSG). During start-up or other transient conditions in combined cycle configurations, the high-pressure steam piping and condenser is a major noise producer, with steam bypassing the STG. The combustion turbine and generator (CTG) are typically housed in acoustical enclosures, thereby dropping their respective noise source ranking. Other balance-of-plant (BOP) equipment also generates noise. The cumulative effects of fuel gas compressors, air compressor skids, boiler feed water pumps, lube oil coolers, and other equipment may affect far-field noise levels.

Prediction of Impacts:

Methodology: The environmental noise prediction model SoundPLAN 7.2 was used for modelling noise emissions from the use of power plant equipment and vehicular movement in the access road. It has been assumed that all the plant equipment will adhere to the equipment noise emission criteria of 85 dB(A) noise level at a distance of 1 m from the source. Operation of equipment with 100% usage scenario was modelled to cover the operation phase of the Project. Major plant components with higher noise generation considered in this study include GTG, STG, HRSG, Auxiliary Boiler, Cooling Tower, CW Pump House, Emergency DG, Water Treatment Facility, Pump House, RMS, and Gas Booster and Conditioning Station. As a conservative approach to the assessment, atmospheric absorption during sound transmission was not included in the assessment. In addition, to represent a worst-case scenario for the assessment, all equipment was assumed to be operating simultaneously. Attenuation due to already constructed boundary and existing Phase I CCPP buildings and structures has been considered in the modelling. Predicted Noise Levels at Receptors: The predicted noise levels within the project AOI during day time and night time is presented in Figure 4.7. Predicted noise levels at nine receptors (where baseline noise levels were also monitored, which include four receptors within or just outside the boundary of the power complex) have been presented in Table 4.9.


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Figure 4.6 Noise Sources and Receptors Location in Topographic Map

Figure 4.7 Predicted Operation Phase Noise Levels -Daytime & Night Time

ONGC Tripura Power Company Limited 726.6 MW+15% CCPP Expansion Project


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ONGC Tripura Power Company Limited 726.6 MW+15% CCPP Expansion Project


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Table 4.9 Predicted Noise Levels at Receptors during Operation Phase II Project

Receptor Code Approximate Distance to OTPC Boundary (m) and Direction from Project Site

Baseline Sound Pressure Levels at Receptors, Leq (dBA)(1)

Predicted Sound Pressure Levels at Receptors, Leq (dBA)

Total Sound Pressure Level (Baseline + Predicted), Leq (dBA)

Applicable Standard (dB(A))(2) as per Landuse

Leq d* Leq n* Leq d Leq n Leq d Leq n Leq d Leq n

NQ1 3,800 m (NE) 53.8 43.7 0.0 0.0 53.8 43.7 55 45 NQ2 800 m (W) 42.0 38.6 20.7 20.7 42.0 38.7 55 45 NQ3 5,100 (WSW) 43.7 38.9 0.0 0.0 43.7 38.9 55 45 NQ4 750 m (E) 42.4 37.6 15.8 15.8 42.4 37.6 55 45 NQ5 Within Plant 66.0 53.1 34.6 34.6 66.0 53.2 75 70 NQ6 960 m (NW) 41.7 38.9 13.7 13.7 41.7 38.9 55 45 NQ7 1,500 (SSE) 41.8 38.5 5.1 5.1 41.8 38.5 55 45 NQ8 1,700 m (WNW) 42.5 38.4 10.0 10.0 42.5 38.4 55 45

(1) Ambient noise levels as monitored during the baseline survey (2) The Noise Pollution (Regulation and Control) Rules, 2000 and amendments thereof (3) All operations have been considered as continuous and hence there is no change in the day and night time prediction results.


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It is evident from Table 4.9 that ambient noise levels due to operation of OTPC Phase II project will be well within the applicable standard during day time and night time in all the 8 receptors in the study. The noise impact from OTPC Phase II operation during day time and night time is expected to be minor. Impact Noise quality impact due to operational activities








Low Medium High



Mitigation Measures

To mitigate operational noise impacts the detailed design specifications will have the following measures in place:

Selection of equipment with lower sound power levels (< 85 dB); Installation of mufflers on engine exhausts and compressor components; Installation of acoustic enclosures for equipment (e.g. gas turbine, compressor) casing radiating noise; Buildings will be designed with improved acoustic performance and sound insulation will be provided; Installation of acoustic barriers without gaps and with a continuous minimum surface density in order to minimize the transmission of sound through the barriers; Installation of vibration isolation for mechanical equipment; and A noise analysis of all major plant components will be carried out during commissioning of the plant to ensure compliance with the specification and guaranteed performance as well as ambient noise levels at the receptors located in the surroundings.

Residual Impact: Considering the implementation of above mentioned mitigation measures, the residual impact on noise quality is assessed to be negligible.

4.3.5 Potential Impact on Road & Traffic

Source of Impact: The source of impact is additional traffic load due to proposed construction activities and operational vehicles for transport of raw manpower. Assessment of Impact: From the proposed expansion unit, approximately, additional 20-25 trucks/trailers per day carrying construction material and plant and machineries will be using the national highways (NH-44) and site


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access road (Udaipur –Kakraban road). 10 to 15 vehicles will be required for transport of contracting workers. Based on the traffic survey conducted (Refer Section 3.2.5), it is noted that Udaipur –Kakraban road is the main road for transportation of construction material and plant and machineries. The average peak hourly traffic on this route is 236 PCU. From the proposed project, additional ~42 PCU’s per hour will be generated on this route. As per IRC, carrying capacity of this approach road is 800 PCU. The maximum PCU on the road will be 278 after expansion. Thus, the road is capable of carrying the excess traffic from the proposed project. The increase of traffic during construction phase will not cause perceptible changes in the existing road traffic in Udaipur–Kakraban road. During operational phase, major raw materials natural gas and water will be transported through pipeline. During operational phase, small cars, two-wheelers and cycles will be utilised for operational workers. The increase of traffic load in the site access road may not cause major changes the traffic load. The potential impact on road and traffic due to operational traffic is assessed to be minor. Impact Road and traffic impact due to operational activities










Mitigation Measures: Precautions as mentioned will be taken for transportation of raw material and finished products:

Trucks with be covered with tarpaulins before traveling on public roads; No overloading is done will be ensured; PUC Certified vehicles will be used; The engines and exhaust systems of all vehicles and equipment used will be maintained as such, that exhaust emissions are low and do not breach statutory limits set for the concerned vehicle/equipment type.

Residual Impact: Considering the implementation of above mentioned mitigation measures, the residual impact disturbance/ discomfort to local people due to increase of traffic is assessed to be negligible.


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4.3.6 Potential Impact on Land Use

The proposed expansion unit will be constructed within the available land of the existing main plant, which is industrial land. Additional land will not be required for the proposed project. Therefore, no adverse impact on land use is envisaged.

4.3.7 Potential Impact on Soil Quality

Construction Phase

Source of Impact: The proposed project will be constructed within the plant area, which is already developed. The construction of plant on this site, would not affect the soil quality of the site. The potential source of impact on soil quality could arise due to spillage of fuel, lubricant and paints from storage site.


Construction waste will be utilised for filling of site within the plant; Municipal solid waste generated from the construction site will be disposed in the Udaipur Town waste dumping site.

Impact Assessment: The fuels, chemical, lubricant etc., would be stored at a designated area which is paved. Thus the contamination of soil can happen only due to accidental spillage of fuel, lubricants and paints from storage areas and during the transfer of fuels and lubricants. The primary monitoring results of soil quality results shows that there was no contamination of heavy metals and other soil contaminants in the nearby agricultural land or open land (Refer Section 3.2.1). The accidental spillage may not cause contamination of soil of nearby agricultural land. The potential impact on soil quality is assessed to be minor. Impact Soil quality impact due to construction activities








Low Medium High



Mitigation Measures: The proposed control measures are as follows:

Dispose debris and waste in designated areas and as per plan to prevent degradation of soil;


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Manage spills of contaminants on soil using standard engineering practices Residual Impact: Considering the implementation of above mentioned mitigation measures, impact on soil quality is assessed to be negligible. Operational Phase

Source of Impact: Potential impact on soil quality could arise due to: Accidental spillage of fuel and lubricant from storage facility or handling site; Improper storage and disposal of hazardous waste; Surface runoff from spillage area into nearby agricultural land; Accidental discharge of untreated effluent into nearby agricultural land.

Embedded Controls: The project embedded control measures are as follows:

Impervious storage area, especially for fuel and lubricant, hazardous waste, etc.; Effluent from the plant will be treated in the ETP and recycled and reused within the plant; Storm water drainage system to channelize the rainwater harvesting pits and accumulated water will be stored in the surface water reservoir for use in the plant.

Impact Assessment: The fuels, lubricant, chemical, etc., would be stored at a designated area which is paved. Thus the contamination of soil can happen only due to accidental spillage of fuel, lubricants and chemicals from storage areas and during the transfer of fuels and chemicals. The surface runoff from spillage site to nearby land may lead to contamination of soil. The primary soil quality monitoring results shows that, nearby soils were not contaminated from the existing operation of the plant. The soil contamination from the above mentioned activities is likely to affect the soil quality of nearby area. These contaminations may have long term effect on the soil quality. Considering project embedded control measures, contamination of soil can happen only during accidental cases or in case of improper management. The potential impact on soil quality is assessed to be minor. Impact Soil quality impact due to operational activities











169

Mitigation Measures: The following mitigation measures are will be implemented:

Ensure proper spill control and management at site; Monitor and detect any contamination on soil & ground water; Good housekeeping to prevent spillage and runoff from site.

Residual Impact: Considering the implementation of above mentioned mitigation measures, impact on soil quality is assessed to be negligible.

4.3.8 Potential Impact on Surface Water Resource

Construction Phase

Source of Impact: Water is required for various construction activities such as concrete preparation, curing etc. and for domestic usage. Impact Assessment: Water requirement during construction phase will be met through the existing water drawl of water up to 25320 m3/day from Gumti River. During construction phase there will be no additional demand on water resources beyond the permitted capacity. During construction of the proposed plant, it is estimated that a maximum of ~100-125m3/day of water will be required during peak construction phase. Hence, there is no impact envisaged on surface water resources during construction phase. Operational Phase

Source of Impact: Additional water requirement for proposed expansion project is 20400 m3/day. And same will be sourced from the Gumti River. Embedded Control Measures: The project embedded control measures are as follows:

The treated effluent will be recycled in the process and greenbelt plantation area.

Impact Assessment: The existing water requirement for the plant is 25,320 m3/day. The water requirement for the proposed expansion unit will be 20400m3/day. After expansion total water requirement will be 45720 m3/day. The water will be sourced from Gumti River. The proposed additional water withdrawal may not cause significant change of availability of water to downstream users. The potential impact is long term, i.e. entire lifecycle of the project. The potential impact on surface water resources due to water withdrawal for proposed expansion unit is assessed to be moderate. Impact Surface water resource impact due to additional water withdrawal






170




Low Medium High



Mitigation Measures: proposed mitigation measures as follows:

Detailed water budgeting and possibility of reuse and recycle of treated water need to be assessed for existing unit; Implement the rainwater harvesting plan prepared for the tlant and harvested water shall be stored in the raw water reservoir for industrial use.

Residual Impact: Considering the implementation of above mentioned mitigation measures, impact on ground water resources is assessed to be moderate.

4.3.9 Potential Impact on Surface Water Quality

Construction Phase

Source of Impact: The potential source of impact surface water quality may arise out of the following:

Surface runoff from construction site; Generation and disposal of domestic waste water from construction camp.


Domestic waste water will be treated through septic tank and soak pit. Storm water drainage with sedimentation tank.

Impact Assessment: During construction phase, OTPC-Palatana will provide sanitation facilities at the construction site and also the existing facilities will be utilised. The domestic wastewater will be treated through septic tank and soak pit. Therefore, sewage will not be disposed in the river or water bodies. The existing OTPC-Palatana plant has the storm water drainage system and also having sedimentation tank. The plant has implemented the rainwater harvesting system, in which surface runoff from the plant will be collected in the pits and same will be pumped into raw water reservoir. The proposed expansion unit will be constructed within the main plant site and existing storm water drainage system will be utilised. However, incase of heavy rainfall lasting for very long hours, the surface runoff may be spilled into the nearby agricultural land or local drainage channel, - finally joins with Gumti River. Therefore, surface runoff with sediment load and oil and chemical containment from spillage site may cause adverse impact on surface water quality.


171

The Gumti River is not an ecological sensitive area in terms of fish habitat, breeding and nursing ground. The water quality of the river is fit for the wildlife (CPCB Use Class category D) and also no major contamination was recorded (Refer Section 3.2,5). The surface runoff from construction site and discharge into the river may not cause perceptible changes in the existing baseline condition (TDS, TSS, BOD level, etc). The discharge of large volume of runoff may have impact downstream of 1-2 km from discharge point. The impact is likely to be occurred during heavy rainfall period. The potential impact on surface water quality due to construction activities is assessed to be moderate. Impact Surface water quality impact due to construction activities








Low Medium High



Mitigation Measures: The mitigation measures are as follows:

Channelize the all surface runoff from construction site through the storm water drainage system and provide adequate size double chambered sedimentation tank; Prevent & mitigate spill of paint/fuel within the construction site.

Residual Impact: Considering the implementation of above mentioned mitigation measures, impact on surface water quality is assessed to be minor. Operational Phase

Source of Impact: The potential source of impact on surface water quality may arise out of the following:

Generation and discharge of plant effluent; Generation and discharge of sewage; Surface runoff from plant.


Process effluent from plant will be treatment through ETP; Treated effluent will be recycled and reused into the process to maintain the Zero Discharge; Domestic waste water will be treated through septic tank and soak pit; Storm water drainage with sedimentation tank.


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Impact Assessment: Total effluent generated from the plant (Phase I) is 5858 m3/day. The effluent is being treated in the ETP; part of the treated effluent (1000 m3/day) is being used for landscaping & greenbelt and balance water (4858 m3/day) is being disposed in the Gumti River after meeting discharge standard.

The effluent generated from the proposed expansion plant (Phase II) will be 5808 m3/day. The effluent generated from Phase II will be treated in ETP then RO Plant. Approximately, 3792 m3/day RO treated water will be generated and same will be utilised as cooling makeup water in Phase II cooling system. ETP Reject (HRSCC +Filter DWF + RO) – 2016 m3/day will be used for Greenbelt & Horticulture. The proposed expansion unit (Pahse II) will be operated as zero discharge (Refer Section 2.9.3).

The climatological data shows that the average annual rainfall was 2000 mm and peak rainfall was 340 mm in the month of July, August and September (Refer Section 3.2.2). During peak monsoon months, approximately, 240 m3/hr run-off water is likely to be generated. The rainwater harvesting plan of OTPC-Palatana, reveals that 1267 ML of rainwater will be harvested and same will be pumped into surface water storage site. The rainwater harvesting system is capable of handled peak runoff from the site. Therefore, discharge of runoff water from site to nearby agricultural land or Gumti River is minimal. The accidental discharge of surface runoff from sedimentation tank may affect the surface water quality of the river.

As discussed in the earlier section (Refer: Surface water quality impact during construction phase), the Gumti River is not categorised as sensitive receptor. The surface runoff or accidental discharge from plant site may not cause perceptible changes in the existing baseline condition. The discharge of large volume of water may have impact downstream water quality up to 1-2 km from discharge point. The potential impact on surface water quality due to above mentioned activities is assessed to be moderate. Impact Surface water quality impact due to operational activities








Low Medium High



Mitigation Measures

Following mitigation measures will be implemented to minimize the impact on the water environment:


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Proper operation and maintenance of ETP to meet the discharge standard; In case of spillage and leakage of fuels and lubricant will be immediately controlled and dispose into designated area; Overflow of Sedimentation tank during heavy rain fall will be prevented by regular pumping into surface water reservoir; Channelize all surface runoff from the plant to the storm water drainage system and provide adequate size double chambered sedimentation tank; Oil water separator will be installed in the surface runoff drainage system of main plant area.

Residual Impact: Considering the implementation of above mentioned mitigation measures, impact on surface water quality is assessed to be minor.

4.3.10 Potential Impact on Ground Water Resources

No adverse impact on ground water resources is envisaged as no abstraction of ground water is proposed during construction phase as well as operation phase of the project.

4.3.11 Potential Impact on Ground Water Quality

Construction Phase

Source of Impact: The potential source of impact on ground water could arise due to contamination from spillage of oil and chemical on open land. Embedded Control Measures: The project embedded control measures are as follows:

Storage of chemical, fuel in paved storage area.

Impact Assessment: The fuels, chemical, lubricant etc., will be stored at a designated area which is paved. Thus the contamination of groundwater can happen only due to accidental spillage of fuel, lubricants and chemicals from storage areas or and during the transfer of fuels and chemicals. The ground water table in the study area was below 10.25m bgl during summer season and 3.89 m bgl during post monsoon season. The soil type of the area is alluvium and clayey loam (Refer Section 3.2.1). This type of soil does not allow easy percolation into the subsoil and subsequently the ground water. The spillage of chemical and fuel may not be easily contaminated the ground water. The ground water quality of the study area reveals that there was no contamination (Refer Section 3.2.5). The spillage of chemicals and fuel may not result in measurable changes in the ground water quality. The construction activity is short term, i.e. 30-33 months. The potential impact on ground water quality is assessed to be minor. Impact Ground water quality impact due to construction activities



174







Low Medium High




Prevent & mitigate spill of paint/fuel within the construction site. Regularly monitored the ground water quality.

Residual Impact: Considering the implementation of above mentioned mitigation measures, impact on ground water quality is assessed to be negligible. Operational Phase

Source of Impact: Potential impact on ground water quality could arise from: Spillage and leakage of fuel & chemical storage and loading and unloading site:

Embedded Controls Measures: The embedded control measures are as follows:

Impervious storage area, especially for fuel & lubricant, chemical, hazardous waste, etc.

Impact Assessment: The fuels, chemical lubricant etc., will be stored in a designated area which is paved. Thus the contamination of groundwater may happen only due to accidental spillage of fuel, lubricants and chemicals from storage areas and during the transfer of fuels and chemicals. As discussed the ground water level in area was shallow (Refer; impact on ground water during construction phase). The soil type of the area is alluvium and clayey loam. This type of soil does not allow easy percolation into the subsoil and subsequently the ground water. The spillage of chemical and fuel may not be easily contaminated the ground water. The ground water quality of the study area reveals that there was no contamination (Refer Section 3.2.5). The spillage of chemicals and fuel may not cause measurable changes in the ground water quality. The potential impact on ground water quality is assessed to be minor

Impact Ground water quality impact due to contamination from operational activity





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Low Medium High



Mitigation Measures: The following mitigation measures are will be implemented:

Ensure proper spill control and management at site; Monitor groundwater from time to time to detect any contamination.

Residual Impact: Considering the implementation of above mentioned mitigation measures, impact on ground water quality is assessed to be negligible.

4.3.12 Potential Impact Terrestrial Habitat

Construction Phase

Source of Impact: The expansion unit will be constructed within the main plant area; the proposed site has no vegetation. Therefore, vegetation clearance would not be required for this project. The potential source of impact from this project is due to habitat disturbance due to fugitive dust & gaseous emissions and noise generation. Impact Assessment: The proposed project site and study area (10 km around the project site) has different types of habitat like natural forest, block plantation, homestead vegetation, agricultural land, etc. The ecological survey has reported 11 species of mammals, 50 species of birds and 10 species of reptiles in the study area. The ecological baseline study has also reported the presence of one schedule I mammals and three species of Schedule I bird. The potential impact on terrestrial habitat including protected species due to proposed expansion project is discussed in the following section. Vegetation Clearance: The proposed expansion unit will occur within the existing premise of the OTPC-Palatana plant site. The construction phase will not involve any felling of trees, since it is an expansion project for an existing industry. The greenbelt within the project site is expected to arrest fugitive emissions generated during construction phase. The impact on the terrestrial flora and fauna is assessed to be minor during the construction phase Noise & Vibration: The operation and construction machineries and vehicles will generate noise and vibration. The increased level of noise and vibration in and around proposed project site may cause disturbance to local faunal species. However, it is expected that the noise will be attenuated within the 200-300 m from the construction site. There is no natural forest within the 500 m from the


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plant. The potential impact on fauna including protected bird species is assessed to be minor. Impact Impact on Terrestrial Habitat due to construction activities










Operational Phase

Source of Impact: Impacts to the terrestrial habitat during operation phase may happen due to air emission, noise and light from industrial activities. Impact Assessment: Air Emission: The major pollutant from the operation of gas based thermal power plant is NOx. The baseline NOx level varies from 21.01 g/m3 to 24.13

g/m3. The proposed expansion unit will also contribute NOx. The predicted concentration of NOx from proposed expansion unit (baseline concentration + incremental concentration) will be 21.01 g/m3 to 25.83 g/m3. The atmosphere of the earth is 80% dinitrogen (N2), which equals about 75 × 106 kg above each hectare of the earth’s surface. In unpolluted conditions a small fraction (1–15 kg N/ha per year) is converted by nitrogen-fixing microorganisms to biologically more active forms of nitrogen: ammonium (NH4+) and nitrate (NO3–). The natural deposition of nitrogen containing atmospheric compounds other than N2 is much less. Human activities, both industrial and agricultural, have strongly increased the amount of biologically active nitrogen compounds, thereby disturbing the natural nitrogen cycle. Various forms of nitrogen pollute the air, mainly nitric oxide (NO), NO2 and NH3 as dry deposition, and NO3– and NH4+ as wet deposition. Nitrogen-containing air pollutants can affect vegetation indirectly, via chemical reactions in the atmosphere, or directly after being deposited on vegetation, soil or water. The direct impact of airborne nitrogen is due to toxic effects, eutrophication and acidification. Two different types of effect threshold exist: critical levels and critical loads. The critical level (CLE) is the concentration in the atmosphere above which these is direct adverse effects on receptors, such as plants, ecosystems. The Critical Levels for NO2 is cited in


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‘Effects of nitrogen containing air pollutants: critical levels; Air Quality Guidelines – Second Edition’.

Table 4.9 Critical Levels for NO2

Concentration (μg/m3) Exposure Time Remarks 95 4 hours The incremental value of NO2

in ambient air after expansion project clearly indicates that concentration will be below critical level.

30 Annual mean 800 1 hour 60 Growing season 40 Winter

Impact on flora & fauna: With respect to critical level of NO2 value of NO2 in ambient air after expansion project is well within the range, proposed expansion project may not have significant impact on vegetation. The concentration NO2 within the ambient air quality standard may not cause significant impact on fauna. The impact on flora and fauna due to process emission from the plant is assessed to be minor. Impact Impact on Terrestrial Habitat due to operational activities








Low Medium High



4.3.13 Impact on Aquatic Habitat

Source of Impact: The Gumti River is an important habitat for fishes and other aquatic fauna. Therefore, impact on river water quality due to proposed construction activity may have direct and indirect impact on aquatic habitat including fishes. The river water quality may impact, due to an increase of sediment loads, pollutants like oil & grease, etc. Impact Assessment: Sedimentation: The sedimentation is likely to occurs due to surface runoff from the construction site. The proposed expansion units will be constructed on the available land in the existing main plant area. As the site is already developed, major soil work will not be required. It is also proposed that, the surface runoff from the construction site will be channelized to existing sedimentation tank before discharge into the reservoir.


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Oil & Grease Contamination: During construction activities, construction machineries and vehicle will be utilised. For the operation of construction machineries and vehicle, oil (diesel) and lubricant will be utilised; accidental spillage and leakage of oil and lubricant is likely to get mixed up with runoff water. The discharge of oil and grease contaminated runoff water without treatment has likely impact on water quality of the receiving water body. Organic Load: During construction activity, approximately 150-200 workforce (peak construction period) will be engaged. It is estimated that, 12 to 16 KLD wastewater will be generated from the construction site. It is proposed to treat the waste water through septic tank and soak pit. Discharge of surface runoff with high sediment load, spilled oil & lubricant and domestic wastewater at Gumti River have the potential to affect the water quality of the river by increase in turbidity, organic content, etc. The increase of pollution (sediment, oil & grease, organic pollutant) has a direct impact on the physical and biological characteristics of the river basin. However, given the proposed control measure the proponent would be taking in treatment of the run-off (by sedimentation tank, spill prevention measures, etc.), it may not cause significant increment in pollution load to the receiving water body and subsequently may not cause significant impact the local aquatic ecology. The potential impact on aquatic habitat including fishes due to above mentioned activity is assessed to be minor. Impact Impact on Aquatic Habitat due to construction activities








Low Medium High



Operational Phase

Source of Impact: Impacts to the aquatic habitat during operation phase may happen due to:

The proposed expansion project will involve water intake (850 m3/hour- 0.68% of the lean season flow of the river) from Gumti River for use in process; Discharge of surface runoff water.

The ecological survey reveals that 70 species of fish have been reported in the Gumti River. The unorganised fishing is also observed in the river by the nearby


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villagers. It is also a habitat for Two-spot Barb (Puntius ticto) fish, an IUCN Vulnerable 2016.v3 species which are available in low numbers. A total of 14 species of phyto planktons and 13 species of zooplankton were observed in the River (Refer section 3.3.5) in ecological baseline section. Embedded Control Measures: The project embedded control measures area as follows:

Effluent from the proposed expansion project will be treated through the ETP and treated water will be recycled.

Accidental discharge of surface runoff & untreated effluent: Accidental discharge of surface runoff with high sediment load, spilled oil, etc into the river have the potential to affect the water quality by leading to an increase in turbidity, organic matter content, oil content etc. Industrial effluent will be adequately treated in the ETP to meet the industrial effluent discharge standards. It is also proposed that all the treated effluent from the proposed expansion project will be utilised within the plant for maintaining zero discharge. The surface runoff from the plant site will be treated through sedimentation tank and then will be pumped into surface water reservoir. As discussed in Section 4.3.8, during heavy rainfall sedimentation tank may be get filled up and water may overflown into the storm water drainage system. In this situation sedimentation tank water is likely to get discharged into the river. This discharge may affect the surface water quality of the river as well as aquatic ecology of the river. Considering the accidental release of sedimentation tank water into the river and surface runoff from the plant, the impact on aquatic ecology is assessed to be minor Impact Impact on Terrestrial Habitat due to operational activities








Low Medium High



4.3.14 Potential Impact on Socio-economic Environment

The assessment of socio-economic impacts due to the expansion of OTPC thermal power plant has considered the following context and project activities:


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The proposed expansion of OTPC power plant will not entail any additional land requirement or expansion of the existing project footprint. It is understood that the existing road infrastructure will be utilised for transport of plant and machineries. During operational phase major raw materials- natural gas and water will be transported through existing pipeline network; however the manpower and chemicals and oil will be transported through existing road. There will be incremental change in the workforce during construction and operations phase. A majority of the workforce is likely to be from the local areas;

As observed in the interaction matrix between project activities and key socio-economic baseline resources/receptors, there is minimum to negligible interactions except for the following:

Employment; Local economy; and Infrastructure & services.

The extent and intensity of impacts is not likely to be significantly different between the construction and operations phase. As a result, the description of socio-economic impacts and its significance has considered the receptor or resource holistically across the project lifecycle. Potential Impact on Employment Generation

Source During the construction phase, approximately 500 workers will be engaged for the expansion work. Considering the type of work that is entailed, highly skilled migrant workers from outside of the local area are likely to be contracted. However, it is understood that for all civil work, local workers will be preferred. The total workforce strength during the operations phase is likely to increase from 155 to 235. Of this, the major increase will be in the worker category instead of the staff category. There is one hostel within the premises for staff. There are approximately 40 staffs that reside presently. The township outside the plant premises is under construction. It is understood that local people provide services to families in the residential township which thereby creates indirect employment opportunities. Assessment of Impacts While the proposed expansion project will generate only incremental employment, the indirect opportunities due to the increase in residents of the township will generate employment, especially in the immediate vicinity of township for manual/casual labour and services. Employment generation during construction and operations phase is a positive impact.


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Impact Increase in local employment opportunities.







Local Economy

Source

The expansion project is likely to result into indirect employment and local procurement opportunities through the following:

Increase in procurement of consumables; Requirement for ancillary services associated with truck transport, maintenance, township development, housekeeping etc.

Assessment of Impacts

There is likely to be local economic benefits due to the increase in activities linked to the construction and operations phase. During construction economy gets significant boosts as requirement of labour, construction materials, finishing materials, hotels, transport etc increases manifold.. Local economic impact due to the expansion is positive. Impact Increase in the local economy







Box 0.1 Infrastructure and Services

Source: The proposed expansion may result into an increase in the project’s pressure on local infrastructure and services, such as access roads and water. Embedded Controls: Considering the scale of expansion, the additional requirements are likely to be managed through existing provisions in place. Assessment of Impacts: The plant premises have a direct access through Udaipur-Kakraban road. The proposed township will be accessed through the same road. The construction material, plant and machineries will be transported through this road. The increase of traffic load may cause damage of road as well the flow of the traffic; this may cause inconvenience to the local people.


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The plant utilises surface water from Gumti River through pipeline. During the operations phase, the water requirement will increase from 25,320 m3/day to 41,856 m3/day. The assessment of surface water resources has indicated that there will be minor impacts and hence, no community disruption of water resources is expected. It is understood that the premises and the township have existing educational and medical facilities for workers and their families. Hence, additional resources from the district will not be required. The potential of pressure on local infrastructure and services is likely to be moderate. Impact Impact on local infrastructure and services








Low Medium High


Significance of impact is considered moderate

Mitigation Measures

The community development activities of OTPC should be increased in collaboration with the local administration and district level authorities. The key community needs include access to potable drinking water and increase in health facilities. A Grievance Redressal Mechanism should be put in place on site to capture any grievances linked to use of infrastructure and resources. The mechanism should be tracked as a part of the HSE team. In addition, ongoing community consultation and engagement should be an integral aspect of local community development. OTPC should implement CSR plan in consultations with villagers, Panchayat and NGO to address the local need and expectation of the people.

4.3.15 Potential Impact on Occupational Health & Safety

Construction Phase

Source of Impact: Occupational health and safety impacts during construction phase are anticipated primarily from operation of construction machineries/ equipment during site preparation and operation of labour camps for housing of onsite workers.


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Provision of drinking water facility, sanitation and cooking facilities; Provision of proper PPEs for the contractor workers onsite

Assessment of Impact: During construction phase impact on occupational health and safety of contractor workers is anticipated from exposure to high noise generated from operation of heavy machineries /equipment and fugitive dust generated from material stockpiles, earth works and vehicular emission. It is estimated that about 500 workers will be deployed by the contractor. Continuous exposure of workers to high noise levels and fugitive dust may lead to adverse health impacts viz. headache, asthma, allergy, hearing loss etc. However, considering the temporary nature of the construction phase activities, intermittent operation of machineries/equipment and provision of proper PPEs for the workers, it may not cause any significant impact. The outstation project workforce will be housed in labour camp located in the plant. It is proposed to provide the adequate facilities in the labour camp like housing facility with proper ventilation, electricity, separate kitchen, solid waste collection facility, drinking water facility, sanitation facility, etc. Inadequate facilities and unhygienic condition may have impact on occupational health of the labourers. The impact on occupation health and safety due to above mentioned construction activities is assessed to be minor. Impact Impact on occupational health & safety due to construction activities








Low Medium High


Significance of impact is considered minor

Mitigation Measures: The mitigation measures are as follows:

Adequate provision of healthy living conditions will be ensured in the contractor labour camp as per National Policy on Safety, Health & Environment at Work Place.; Exposure of workers operating near high noise generating sources will be reduced to the extent possible; Health surveillance of contractor workforce will be conducted


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Occupational health and safety of contractor workforce will be assured through the formulation of an “Occupational Health & Safety Management Plan”.

Residual Impact: Considering the implementation of above mentioned mitigation measures, impact on occupational health and safety is assessed to be negligible. Operational Phase

Source of Impact: The source of occupational health and safety could arise from: Exposure in high noise generation area.

Embedded control measures: The control measures are as follows:

Provision of PPE’s to all workers Assessment of Impact: Occupational health and safety impact during operational phase is also anticipated from exposure of project personnel to high noise levels generated from boilers, compressor, pumps and cooling towers. Continuous exposure of workers to high noise levels and fugitive dust may lead to adverse health impacts viz. headache, hearing loss etc. However, considering intermittent operation of machineries/equipment and provision of proper PPEs for the workers, it may not cause significant impact. Potential impact on occupational health and safety is assessed to be moderate. Impact Impact on occupational health & safety due to operational activities








Low Medium High



Mitigation measures: The mitigation measures are as follows:

All potential occupational health hazards will be identified Provision of proper PPEs and maintenance of workplace condition in compliance with specific provision of the Factories Act 1948 shall be ensured; Prolonged exposure of personnel operating in chlorine storage and handling unit or near high noise generating areas will be reduced to the extent possible;


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Health surveillance will be conducted of personnel working in the aforesaid areas. Periodic inspection and audits will be conducted.

Residual Impact: Considering the implementation of above mentioned mitigation measures, impact on occupational health and safety is assessed to be minor.

4.3.16 Potential Impact on Community Health and Safety

Construction Phase

Source of Impact: The community health and safety may arise due to changes in environmental quality, increased prevalence of disease and increase in traffic movement. Embedded Controls: The following control measures have been proposed:

Proper collection, storage and disposal of MSW;

Assessment of Impact: Dust and Noise Discomfort: Inhabitants residing close to access roads will be affected due to noise and dust generated from vehicular movement during construction phase. However, the access road is a paved road and the dust generation will be minimum. Transmission of infectious diseases: Approximate 500 workers will be employed in the construction phase. Improper sanitation facility and disposal of municipal soil waste from the construction labour camp can cause vector borne diseases and other infectious diseases. Traffic movement in site approach road: The construction activities are expected to increase traffic load in the site approach road which may create public safety issues for local residents and school children of nearby primary school. Potential impacts include pedestrian safety issues and safety aspects of slow moving vehicles. Considering project embedded control measures, the impact on community health & safety is assessed to be moderate. Impact Impact on community health & safety due to construction activities








Low Medium High




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Mitigation measures: The possible mitigation measures to address the aforesaid impacts include:

Dust control measures will be taken along site approach road; Domestic waste generated from construction site will be disposed in the solid waste dumping site; Spread/transmission of communicable diseases from influx of contractor workforce will be mitigated;

Residual Impact: Considering the implementation of above mentioned mitigation measures, impact on community health and safety is assessed to be minor. Operational Phase

Source of Impact: The community health and safety may arise due to changes in environmental quality and increase in traffic movement. Embedded Controls: The following measures have been proposed:

Emission (NOx) control through dry low NOx burner; Treatment of effluent and reused and recycling within the plant; Treatment of domestic waste water through STP;

Assessment of Impact: The major air pollutant from the existing and proposed expansion unit is NOx. The emission of NOx will be controlled through dry low NOx burner. The emission level will be maintained well below the permissible limit. The air quality modelling study reveals that, in normal plant operation the incremental NOx level will be well within the NAAQS (Refer Section 4.3.2).

The process effluent will be treated through the ETP and treated effluent will be reused and recycled in the plant. Domestic waste water will be treated through STP and treated effluent will be reused in the plant. In case of normal operation, these wastes (effluent and sewage) will not be disposed outside the plant premises. Impact on community health from these activities is not envisaged.

The potential on community health and safety due to normal operation of plant is assessed to be moderate. Impact Impact on community health & safety due to operational activities








Low Medium High


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Mitigation measures: The possible mitigation measures to address the aforesaid impacts include:

Ensure air pollution control measures planned in the project design to achieve the emission level well within the permissible limit; Install sufficient engineering control on equipment and machineries to reduce noise emission levels at source; Health surveillance will be conducted for villagers residing near the project area.

Residual Impact: Considering the implementation of above mentioned mitigation measures, impact on community health and safety is assessed to be minor.


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5 ALTERNATIVE ANALYSIS

This section provides an analysis of alternatives in relation to the conception and planning phase of the project. This includes the following:

No project scenario; Alternative site location; and Design and technology options.

5.1 NO PROJECT SCENARIO

The no project scenario has been analysed to understand what would be reasonably expected to occur in the foreseeable future, if the proposed project is not developed. In such a scenario, there would not be any pressure on use of local resources and infrastructure, and no adverse effect on local ecology or incremental pollution to baseline environmental components (air, water and noise levels). At the same time, there would not be any positive impact on socioeconomic status of the area resulting from direct and indirect economic benefits that such a project can provide to the locality. The generation and supply of electricity has a significant impact on the national economy of any country. The power scenario brings out the fact that there is a deficit in the current scenario as such and there is a requirement for additional capacity. The gap between demand and supply of power is ever widening even after number of schemes implemented by the private, state as well as central sector agencies. This situation is expected to continue for quite some time indicating the need for capacity addition as much as feasible to reduce the gap between supply and demand. Therefore, there is no alternative to adding more power generating units to the existing power system of India, to help improve and meet the energy demand for both domestic and industrial requirements. The proposed expansion project will generate direct and indirect employment and economic opportunities in this region. In addition, power plant has potential to spur the industrial growth of the region. Such an industrial growth would have the potential to attract direct and indirect investments, generate employment. In case of no project scenario, there would not be any accelerated economic growth in the area and overall induced development. Thus the proposed project scenario involving the expansion of OTPC Palatana Power Plant is considered to be a preferred scenario compared to no project scenario. Oil & Natural Gas Corporation Ltd. (“ONGC”), a public sector Company of the Government of India, which is the largest shareholder in OTPC, owns significant natural gas reserves in the North Eastern state of Tripura. However, these natural gas reserves have not been fully commercially developed due to low industrial demand in the North-Eastern region. The complexities of logistics and attendant costs limit the economic viability of transportation of gas


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to other parts of the country where gas is in deficit. In order to optimally utilize the gas available in Tripura, setting up of gas based power plant will be best scenario.

5.2 SITE ALTERNATIVE

The site alternative study was conducted for a Greenfield site and Brownfield site within the existing industrial facility. The assessment is presented in following table.

Table 5.1 Assessment for Alternative Sites

Criteria Greenfield Site Brownfield Site (within the OTPC- Palatana Plant)

Land There is no demarcated industrial land in the Udaipur area. Therefore setting up of new power plant would require agricultural land or forest land.

The land is available for proposed expansion within the existing plant, no additional land will be required

Facilities & utilities

New facilities and utilities like water intake facility, pipeline for water sourcing, new transmission line,new gas pipeline, new access road would require.

The OTPC Phase I project is located close proximity of perennial River Gumti and plant has water intake facility along with pipeline. The gas pipeline from ONGC gas field is connected with plant. The plant is connected with Palatana-Bongaigon 400kV double circuit Transmission line. All the above mentioned facilities are able to cater the proposed expansion project.

Capital cost Higher capital cost cwould be required ompared to brownfield project due to need for setting up new facilities and utilities for the power plant.

Lower capital cost compared to the green field project, thereby enhancing the competitive strengths and minimizing the cost of production. The site is well connected with roads and railways

Considering the advantages of the present location described above, as well as the limited footprint and impacts, brownfield site location has been considered for the Project. The site for the Project offers following advantages: Technical

Adequate area available for 726 MW + 15% gas fired power plant and associated facilities; Proximity to ONGC gas field and existing gas pipeline connectivity with plant; Access to road and nearby water transportation networks; Available water supply source for process including cooling water;

Social and Environmental

No major sensitive environmental receptors ( such as communities, hospitals, schools, etc.) in close proximity; No physical cultural resources on site and in close proximity (~500 m);


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No resettlement requirements.

5.2.2 Conclusion

The ‘No Project Scenario’ is likely to have a negative effect on opportunities for employment, both directly from the proposed power project and its dependant sectors such as agriculture, industries and manufacturing that require stable power supply in order to operate effectively and be competitive. This will further affect the proposed industrial development in the North-East. The site location is well suited for setting up of power plant with availability of adequate availability of land, water, access to road, fuel source/supply arrangement. Associated facilities, such as, water intake and abstraction mechanism, pump house location, construction laydown and camp areas have also been selected on the basis of alternative analysis and selection of best suited option. The project design has considered embedded pollution control systems, which include NOx control, stack height for dispersion of pollutants, use of cleaner primary fuel (natural gas), use of Gumti River water for the Project as opposed to ground water, induced draft cooling tower for reduced water requirement and no direct discharge of cooling water into river. Within the available alternatives, OTPC has opted for best suited technological option for power generation.


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6 ENVIRONMENTAL MONITORING PROGRAM

The environmental monitoring programme is an important process of any management plan of a development project. Environmental monitoring will be required for both construction and operational phases of the Project. Environmental monitoring will help in:

Assess the changes in environmental conditions, Monitor the effective implementation of mitigation measures, Measure deteriorations of environmental quality for further preventive action(s).

The following monitoring programs are to be carried out at project in order to meet the above objectives:

Ambient air quality Ambient noise quality; Water quality; Soil quality; Emission and discharge from the plant Greenbelt; Social parameters; HSE Audits; and Inspection of Prevention and Control Measures.

6.1 IMPLEMENTATION OF THE ENVIRONMENTAL MONITORING PROGRAM

The implementation of the Environmental Monitoring Program for the proposed project has been delineated in the following sections.

6.1.1 Internal Monitoring

Internal monitoring focuses on measuring and reporting progress of implementing EMP activities. OTPC-Palatana facility has in place a very well structured environment monitoring program. The same shall be continued and strengthened during this proposed expansion project. Environmental Management Cell

OTPC-Palatana facility is certified for ISO 14001:2004, along with ISO 9001 & OHSAS 18001. Within the organization, a matured Environmental Management System ensures that all the environmental issues are discussed and reviewed at the highest level and corrective actions are taken accordingly. The responsibility for ensuring the overall effective implementation of the monitoring program will lie with Head (HSE) of the site, who will play the role of advising the designated managers that are responsible for implementation of


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different aspects of the project (Refer. Section 9.2.1: Organisational structure, roles and responsibility).

Figure 6.1 ISO Certificate of OTPC

6.1.2 External Monitoring & Auditing

OTPC-Palatana will hire an external agency to conduct monitoring and produce half yearly and annual reports for emissions data and wastewater discharges for submission to the Tripura State Pollution Control Board (TSPCB). OTPC-Palatana will submit the environmental compliance report to Regional Office of MoEFCC in every six months, summarizing status of compliance of conditions of Environmental Clearance (EC), Consent to Establish (CTE) and Consent to Operate (CTO) together with reporting on progress of EMP implementation.


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This report shall present monitoring data and findings, describe any significant events or incidents that occurred, and indicate how these events were managed. OTPC-Palatana will also ensure disclosure of its compliance reports on its website as per the requirement of MoEFCC.

6.2 ENVIRONMENTAL MONITORING PROGRAM & SCHEDULE

The existing environmental monitoring program shall be extended for the proposed project activity as well. This will be monitored on a regular basis during the operation phase of the project and shall comply with the Consent conditions prescribed by TSPCB. The details of the environmental monitoring are shown below in Table 6.1.


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Table 6.1 Environmental Monitoring Program

Sl. No.

Activity Aspect Environmental quality/ Performance Indicator

Monitoring Parameter

Location Period & Frequency

Responsibility

A. Construction Phase A.1.1 Site development

& construction of plant including operation of machineries & equipment

Fugitive emission Ambient Air Quality Measurement of PM10, PM2.5, NOx, SO2, CO using ambient air sampler

At surrounding receptor –Palatana, Kakraban, Jamjuri, Dudhpushkarini and OTPC Plant.

Two weeks in every three months for each location

OTPC/Contractor

A.1.2 Dust suppression measures

Visual observation of dust in air by haziness

Site & approach roads Daily during site preparation

OTPC/Contractor

A.1.3 Noise emission Ambient noise quality Measurement of Noise Pressure Level in dB(A)

At surrounding receptor points – Palatana, Kakraban, Jamjuri, Dudhpushkarini and OTPC Plant.

Two times in month during site works

OTPC/Contractor

A.1.4 Noise emission from machineries & equipment

Fit certificate and its maintenance; Acoustic enclosure for DG set

Construction Site During procurement and once in month

OTPC/Contractor

A.1.5 Generation of construction & demolition waste

Offsite disposal Inspection and Audit Disposal site Fortnightly OTPC/Contractor

A.1.6 Spillage of oil & lubricant

Soil Contamination Analysis for suite of contaminants (heavy metals, TPH, organics, pesticides).

Site, adjacent areas Every 3 months during construction period

OTPC/Contractor

A.1.7 Spill prevention measures

Time taken to control the spill Spill location In event of spills over an area of 10 sq.m

OTPC/Contractor

A.1.8 Injury/ accident of construction workers

Occupational health & safety

Incidence reporting

Site Daily during construction period

OTPC/Contractor

A.2.1 Operation of vehicle for transport of construction material & waste

Air emission Ambient air quality Ref. A1.1 Ref. A1.1 Ref. A1.1 OTPC/Contractor A.2.2 Emission from vehicle PUC certificate of vehicle Site During

procurement/ hiring of vehicle

OTPC/Contractor

A2,3 Emission of Back-up DG PM, SO2, NOx, CO of DG stack

Stack Once in every month

OTPC/Contractor

A.2.4 Noise emission Noise level from vehicles Fit certificate and its maintenance; Acoustic enclosure for DG set

Construction Site During procurement and once in month

OTPC/Contractor


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Sl. No.




Responsibility

A.2.5 Surface water quality Analysis of Parameters as per CPCB Use-class

Gumti River receiving run-off discharges; 2 location, upstream & downstream

Once in a month during monsoon season –construction phase

OTPC/Contractor

A.3.1 Storage & handling of construction material

Fugitive emission Ambient air quality Ref. A.1.1 Ref. A.1.1 Ref, A.1.1 OTPC/Contractor A.3.2 Emission control

measures Covered storage facility Storage area Every fortnightly OTPC/Contractor

A.3.3 Operation of Labour Camp

Generation of MSW Solid waste collection system & offsite disposal

Provision of MSW collection facility & disposal in MSW dumping site

Labour camp Every fortnightly OTPC/Contractor

A.3.4 Generation of sewage

Treatment of sewage Provision of Septic tank and soak pit Ground water quality as per IS:10500

Bore well/ Tube well at OTPC Plant and Palatana, Kakraban, Dudhpushkarini

Every six months during construction phase

OTPC/Contractor

A.5.1 Workforce involvement

Health & safety of Construction workers

Health & safety issues Incidence reporting Construction site Everyday OTPC/Contractor A.5.2 Provision sanitation, drinking

water, rest-shelter, first-aid facility

Labour camp and site Every fortnight OTPC/Contractor

A.5.3 Provision of PPE and its use Construction site Every fortnight OTPC/Contractor B Operational Phase B.1. Operation GT & ST B.1.1 Operation of GT

& ST Air emission Stack emission NOx, PM, CO and O2 Stack Continuous HSE

Twice a week for 2 weeks during six monthly compliance monitoring

Third Party NABL laboratory

B.1.2 Ambient Air quality PM10, PM2.5, NOx, SO2, CO At surrounding receptors- Palatana, Kakraban, Jamjuri, Dudhpushkarini and OTPC Plant.

Twice a week for 52 weeks in year for each location

HSE/ Third Party NABL laboratory

B.1.3 Noise generation Work place noise quality Measurement of Noise Pressure Level in dB(A)

Noise generating area of the plant

Once in a month HSE

B.1.4 Ambient noise quality Measurement of Noise Pressure Level in dB(A)



HSE

B.1.5 Noise generation Work place noise quality Measurement of Noise Pressure Level in dB(A)

Noise generating area of the plant

Once in a month HSE


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Sl. No.




Responsibility

B.1.6 Operation of cooling tower, pumps, etc.

Ambient noise quality Measurement of Noise Pressure Level in dB(A)



HSE/ Third Party NABL laboratory

B.1.7 Operation of ETP Generation and discharge of treated effluent

Volume of treated water Quantity At System Outlet which is recycled back in process

Daily HSE

B.1.8 Quality of water - untreated and treated

pH, Temperature, Free available chlorine, TSS, Oil & Grease, Cu, Fe, Zn, Cr, Phosphate

At System Outlet which is recycled back in process through online monitoring system

Daily HSE

B.1.9 Quarterly HSE/ Third Party NABL laboratory

B.2.1

Surface water quality Surface water quality as per CPCB surface water use category.

Upstream and down stream of OTPC water intake/ discharge location

Quarterly HSE/ Third Party NABL laboratory

B.2.3 Operation of STP Generation and discharge of treated effluent

Volume of treated water At System Outlet which is recycled back in process

Daily HSE

B.2.4 Quality of water - untreated and treated

pH, DO, COD, BOD, TDS At System Outlet which is recycled back in process through online monitoring system

Daily HSE

B.2.5 Quarterly HSE/ Third Party NABL laboratory

B.3.1 Sourcing of water from Gumti River

Competitive users Downstream water availability

Water discharge at water intake point

Downstream of water intake point

Daily HSE

B.5.1 Disposal of sludge generated from ETP and STP

Generation of leachate

Quantity of waste disposed in the Captive Landfill Site

Daily waste volume Captive Landfill Site Every day Sr. Officer (Central Lab)

B.5.2 Ground water quality Ground water quality as per IS:10500-2012

Wells near Captive Landfill Site Once in every three months

Dy. Manager (EHS)

B.6.1 Vehicular movement for transportation of manpower

Air & noise emission

Emission from vehicle PUCC Certificate With Drivers at main gate If considerable emissions observed during operations

Dy. Manager Safety

B.7.1 Surface runoff from plant

Discharge into the river

Water quality Analysis of Parameters as per CPCB Use-class

Gumti River receiving run-off discharges; 2 location, upstream & downstream

Once in a season Dy. Manager (EHS)


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Sl. No.




Responsibility

Quantity of harvested rainwater

Volume of water Rainwater harvesting pits Daily during rainy days

HSE

B.8.1 Generation of Hazardous waste

Potential Soil and groundwater Contamination

Regular Inspection and audit

Quantity of waste generated & spillage

Waste collection site At the time of generation

Dy. Manager (EHS)

B.9.1 Storage of Fuels, and Waste/Used Oils



Spillage or leakage Storage site Every day Dy. Manager (EHS)

B.10.1 Accidental oil spills/ chemical spills



Spillage or leakage Storage site Every day Dy. Manager (EHS)

B.11.1 Occupational Health and Safety

Health & safety of the workers

Health check-up Medical surveillance as per Factories Act

All workers Once in year Dy. Manager (EHS)

B.11.2 Provision of PPE and its use Construction site Every fortnight Dy. Manager (EHS) B.12.1 Greenbelt

Development Progress of greenbelt

Achieve annual target Survival rate of greenbelt Plantation area Quarterly Dy. Manager (EHS)


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7 ADDITIONAL STUDIES

7.1 RISK ASSESSMENT & DISASTER MANAGEMENT PLAN

This section on Risk Assessment (RA) aims to provide a systematic analysis of the major risks that may arise as a result of the proposed expansion of the natural gas based power plant of OTPC in Tripura. The RA process outlines rational evaluations of the identified risks based on their significance and provides the outline for appropriate preventive and risk mitigation measures. The output of the RA will contribute towards strengthening of the Emergency Response Plan (ERP) in order to prevent damage to personnel, infrastructure and receptors in the immediate vicinity of the plant. Additionally, the results of the RA can also provide valuable inputs for keeping risk at As Low As Reasonably Practicable (ALARP) and arriving at decisions for mitigation of high risk events. The following section describes the objectives, methodology of the risk assessment study and assessment for each of the potential risk separately. This includes identification of major hazards, hazard screening and ranking, frequency and consequence analysis for major hazards. The hazards have been quantitatively evaluated through a criteria based risk evaluation matrix. Risk mitigation measures to reduce significant risks to acceptable levels have also been recommended as a part of the risk assessment study.

7.1.1 RA Study Objective

The overall objective of this RA with respect to the proposed expansion project involves identification and evaluation of major risks, prioritizing risks identified based on their hazard consequences and using the outcome to guide and strengthen both onsite and offsite ERP. Hence in order to ensure effective management of any emergency situations that may arise from failure of natural gas supply pipelines, the following specific objectives need to be achieved.

Identify potential risk scenarios that may arise from supply of natural gas via pipelines; Review existing information and historical databases to arrive at possible likelihood of such risk scenarios; Predict the consequences of such potential risk scenarios and if consequences are observed to be high, establish the same through application of quantitative simulations; and Recommend feasible preventive and risk mitigation measures as well as provide inputs for strengthening of the project Emergency Response Plan (ERP).

7.1.2 RA Methodology

The risk assessment process is primarily based on likelihood of occurrence of the risks identified and their possible hazard consequences particularly being


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evaluated through hypothetical accident scenarios. With respect to the proposed expansion project, major risks viz. leaks and rupture of pipelines been assessed and evaluated through a risk matrix generated to combine the risk severity and likelihood factor. Risk associated with the proposed expansion of the OTPC gas based power project have been determined semi-quantitatively as the product of likelihood/probability and severity/consequence by using order of magnitude data (risk ranking = severity/consequence factor X likelihood/probability factor). Significance of such project related risks have been then established through their classification as high, medium, low, very low depending upon risk ranking. The risk matrix is widely accepted as standardized method of risk assessment and is preferred over purely quantitative methods, given that it’s inherent limitations to define a risk event is certain. Application of this tool has resulted in the prioritization of the potential risks events for the existing operations and proposed expansion thus providing the basis for drawing up risk mitigation measures and leading to formulation of plans for risk and emergency management. The overall approach is summarized below in Figure 7.1.

Figure 7.1 Risk Assessment Methodology

7.1.3 Safety Controls Proposed for Natural Gas Supply Pipeline

Adequate number of gas leak detection and fire detection system as per stipulated norms will be provided for the pipeline supply of natural gas. Gas


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flow measurement system with integrator and local/remote indication will also be installed. Preventive Measures for Handling of Natural Gas

Leak detection sensors to be located at areas prone to fire risk/ leakages; All safety and firefighting requirements as per OISD norms to be put in place; High temperature and high pressure alarm with auto-activation of water sprinklers as well as safety relief valve to be provided; Flame proof electrical fittings to be provided for the installation; Periodical training/awareness to be given to work force at the project site to handle any emergency situation; Periodic mock drills to be conducted so as to check the alertness and efficiency and corresponding records to be maintained; Signboards including emergency phone numbers and ‘no smoking’ signs should be installed at all appropriate locations; Plant should have adequate communication system; Pipeline route/equipment should be provided with smoke / fire detection and alarm system. Fire alarm and firefighting facility commensurate with the storage should be provided at the unloading point; ‘No smoking zone’ should be declared at all fire prone areas. Non sparking tools should be used for any maintenance; and Wind socks should be installed to check the wind direction at the time of accident and accordingly persons may be diverted in opposite direction of wind.

7.1.4 Hazard Identification

The first stage in any risk assessment is to identify the potential incidents that could lead to the release of a hazardous material from its normal containment and result in a major accident. This is achieved by a systematic review of the facilities to determine where a release of a hazardous material could occur from various parts of the installation. The major hazards are generally one of three types: flammable, reactive and/or toxic. In this study, only flammable hazards are relevant involving loss of containment of diesel and leakage from natural gas pipeline. Flammable hazards may manifest as high thermal radiation from fires and over pressures following explosions that may cause direct damage, building collapse, etc. Flammable hazards are present throughout the facility and associated pipelines. Fires may occur if flammable materials are released to the atmosphere and ignition takes place. Based on the result of this exercise, potential hazards that may arise due to proposed expansion project were identified and a qualitative understanding of their probability and significance were obtained. Taking into account the applicability of different risk aspects the following hazards have been


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identified with respect to the proposed expansion project which has been dealt in detail in the subsequent sections.

Accidental release of natural gas from pipelines leading to jet fire, flash fire or vapour cloud explosion (VCE).

Hazards from Flammable Liquid Storages and Gas Pipelines

There are a number of hazards that are present at the proposed expansion project site that may result in injury to people or a fatality in more serious cases. This study is only concerned with ‘major hazards’, which are as follows:

Jet fires associated with pipework failures; Vapour cloud explosions; and Flash fires.

Each of these hazards has been described below. Jet Fire

Jet fires result from ignited releases of pressurized flammable gas or superheated/pressurized liquid. The momentum of the release carries the material forward in a long plume entraining air to give a flammable mixture. Jet fires only occur where the natural gas is being handled under pressure or when handled in gas phase and the releases are unobstructed. Flash Fire

Vapour clouds can be formed from the release of vapour of pressurized flammable material as well as from non-flashing liquid releases where vapour clouds can be formed from the evaporation of liquid pools or leakage/rupture of pressurized pipelines transporting flammable gas. Where ignition of a release does not occur immediately, a vapour cloud is formed and moves away from the point of origin under the action of the wind. This drifting cloud may undergo delayed ignition if an ignition source is reached, resulting in a flash fire if the cloud ignites in an unconfined area or vapour cloud explosion (VCE) if within confined area. Vapour Cloud Explosion

If the generation of heat in a fire involving a vapour-air mixture is accompanied by the generation of pressure then the resulting effect is avapour cloud explosion (VCE). The amount of overpressure produced in a VCE is determined by the reactivity of the gas, the strength of the ignition source, the degree of confinement of the vapour cloud, the number of obstacles in and around the cloud and the location of the point of ignition with respect to the escape path of the expanding gases.


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7.1.5 Frequency Analysis

The frequency analysis of the hazards identified with respect to the proposed expansion project was undertaken to estimate the likelihood of their occurrences during the project life cycle. Hazard frequencies in relation to the proposed expansion project were estimated based on the analysis of historical accident frequency data and professional judgment. Based on the range of probabilities arrived at for different potential hazards that may be encountered with respect to the supply of natural gas the following frequency categories and criteria have been defined (ReferTable 7.1).

Table 7.1 Frequency Categories and Criteria

Likelihood Ranking Criteria Ranking (cases/year) Frequency Class

5 Likely to occur often in the life of the project, with a probability greater than 10-1

Frequent

4 Will occur several times in the life of project, with a probability of occurrence less than 10-1, but greater than 10-2

Probable

3 Likely to occur sometime in the life of a project, with a probability of occurrence less than 10-2, but greater than 10-3

Occasional/Rare

2 Unlikely but possible to occur in the life of a project, with a probability of occurrence less than 10-3, but greater than 10-6

Remote

1 So unlikely it can be assumed that occurrence may not be experienced, with a probability of occurrence less than 10-6

Improbable

Source: Guidelines for Developing Quantitative Safety Risk Criteria – Centre for Chemical Process and Safety Frequency Analysis – Pipeline

An effort has also been made to understand the primary failure frequencies of pressurised natural gas pipeline to be supplied to the site to serve as a fuel source. Based on the European Gas Pipeline Incident Data Group (EGIG) database the evolution of the primary failure frequencies over the entire period and for the last five years has been provided in Table 7.2 below.

Table 7.2 Primary Gas Pipeline Failure Frequency

Period No. of Incidents Total System Exposure (km.yr)

Primary failure frequency

(1000 km.yr)

1970-2007 1173 3.15.106 0.372 1970-2010 1249 3.55.106 0.351 1970-2013 1309 3.98.106 0.329 1974-2013 1179 3.84.106 0.307 1984-2013 805 3.24.106 0.249 1994-2013 426 2.40.106 0.177 2004-2013 209 1.33.106 0.157 2009-2013 110 0.70.106 0.158

Source: 9th EGIG Report


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As referred in the above table the overall failure frequency (0.33) of the entire period (1970-2013) is slightly lower than the failure frequency of 0.35 reported in the 8th EGIG report (1970-2010). The failure frequency of the last 5 years was found to be 0.16 per 1000km.year, depicting an improved performance over the recent years.

Incident Causes

Gas pipeline failure incidents can be attributed to the following major causes viz. external interference, construction defects, corrosion (internal & external), ground movement and hot tap. The distribution of incidents with cause has been presented in the Figure 7.2 below.

Figure 7.2 Gas Pipeline Failure – Distribution of Incident & Causes

Source: 8th EGIG Report The interpretation of the aforesaid figure indicated external interference as the major cause of pipeline failure contributing to about 48.4% of the total failure incidents followed by construction defects (16.7%) and corrosion related problems (16.1%). Ground movement resulting from seismic disturbance, landslides, flood etc. contributed to only 7.4% of pipeline failure incident causes. Review of the 9th EGIG report indicates that primary failure frequency varies with pipeline diameter, and the same has been presented in Table 7.3 below.

Table 7.3 Primary Failure Frequency based on Diameter Class (1970-2013)

Nominal Diameter (inch) Primary failure frequency (per km.yr)

Pinhole/Crack Hole Rupture

diameter < 5'' 4.45 X 10-4 2.68 X 10-4 1.33 X 10-4 5" diameter < 11" 2.80 X 10-4 1.97 X 10-4 6.40 X 10-5 11" diameter < 17" 1.27 X 10-4 0.98 X 10-4 4.10 X 10-5 17" diameter < 23" 1.02 X 10-4 5.00 X 10-5 3.40 X 10-5 23" diameter < 29" 8.50 X 10-5 2.70 X 10-5 1.20 X 10-5


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Nominal Diameter (inch) Primary failure frequency (per km.yr)

Pinhole/Crack Hole Rupture

29" diameter < 35" 2.30 X 10-5 5.00 X 10-6 1.40 X 10-5 35" diameter < 41" 2.30 X 10-5 8.00 X 10-6 3.00 X 10-6 41" diameter < 47" 7.00 X 10-6 - -

diameter 47" 6.00 X 10-6 6.00 X 10-6 6.00 X 10-6 Source: 9th EGIG Report

The pipeline failure frequency viz. leaks or rupture for the natural gas pipeline has been computed based on the aforesaid table. For pipeline with diameter varying within 5 to 11 inches, the probability of pinhole is estimated to be 2.80 x 10-4 per km year, while full bore rupture is considered to be 6.40 x 10-5 per km year. This is considered for estimating failure probability of the natural gas pipeline having a 8 inch diameter which supplies to gas receiving station onsite. (Refer Table 7.4 below).

Table 7.4 Natural Gas Pipeline - Failure Frequency

Sl. No

Pipeline Failure Case

EGIG Failure Frequency

(per km.year)

Avg. Pipeline Length (km)

Project Pipeline Failure Frequency

(per year)

Frequency

1 Natural Gas Pipeline Rupture

6.40 x 10-5 0.45 2.88 x 10-5 Remote

2 Natural Gas Pipeline Leak

2.80 x 10-4 0.45 1.26 x 10-4 Remote

Thus the probability of pipeline leak and rupture with respect to the pipeline transportation of natural gas as fuel to the site is identified to be as “Remote” (Refer Table 7.1). Pipeline Failure – Ignition Probability

The ignition probability of natural gas pipeline failure (rupture & leaks) with respect to the proposed expansion project is derived based on the following equations as provided in the IGEM/TD/2 standard P ign = 0.0555 + 0.0137pd2; for 0 pd2 57 (For pipeline ruptures) P ign = 0.81; for pd2>57 P ign = 0.0555 + 0.0137(0.5pd2); for 0 0.5pd2 57 (For pipeline leaks) P ign = 0.81; for 0.5pd2>57 Where: P ign = Probability of ignition p = Pipeline operating pressure (bar) d = Pipeline diameter (m)


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The ignition probability of natural gas release from a leak/rupture of 8inch natural gas pipeline is calculated based on the above equations utilizing the following input parameters as discussed below. Natural Gas Pipeline

Normal Pipeline Inlet Pressure (bar) = p= 34 bar

Pipeline diameter = d = 12 inch or 0.20 m

For pipeline rupture pd2 = (34) X (0.20)2 = 1.36

For pipeline leak 0.5 pd2 = 0.5 X (41.3) X (0.20)2 = 0.68

0 pd2 57 and 0 0.5pd2 57,

Since the following equation has been utilized for deriving the ignition probability for failure.

P ign for pipeline rupture = 0.0555 + 0.0137pd2 = 0.0555 + 0.0137 (1.36) = 0.07

P ign for pipeline leak = 0.0555 + 0.0137(0.5pd2) = 0.0555 + 0.0137 (0.68) = 0.06

The probability of ignition for an accidental release of natural gas from pipeline supplying the site is presented in Table 7.5 below:

Table 7.5 Natural Gas Pipeline –Jet Fire Probability

Sl. No

Pipeline Failure Case Project Pipeline Failure Frequency (per year)

Ignition Probability

Jet Fire Probability

1 Natural Gas Pipeline Leak

1.26 x 10-4 0.06 0.75 x 10-5

2 Natural Gas Pipeline Rupture

2.88 x 10-5 0.07 0.20 x 10-5

Hence from the above table it can be concluded that ignition probability of natural gas that may be released from the supply pipeline due to any accidental event is considered to be “Remote”.

7.1.6 Consequence Analysis

In parallel with the frequency analysis, hazard prediction / consequence analysis exercises were undertaken to assess the likely impact of project related risks on onsite personnel, infrastructure and environment. In relation to the proposed expansion project as well as the existing activities have been considered, the estimation of the consequences for each possible event has been based either on accident frequency, consequence modeling or professional judgment, as appropriate. Overall, the consequence analysis takes into account the following aspects:

Nature of impact on environment and community; Occupational health and safety; Asset and property damage; Corporate image; and Timeline for restoration of property damage.


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The following criteria for consequence rankings (Refer Table 7.6) have been drawn up in context of the possible consequences of the risk events that may occur during the proposed project expansion operations:

Table 7.6 Severity Categories and Criteria

Consequence Ranking Criteria Definition Catastrophic 5 Multiple fatalities/permanent total disability to more than

50 persons. Net negative financial impact of >10 crores International media coverage Loss of corporate image and reputation

Major 4 Single fatality/permanent total disability to one or more persons Net negative financial impact of 5 -10 crores National stakeholder concern and media coverage.

Moderate 3 Short term hospitalization & rehabilitation leading to recovery Net negative financial impact of 1-5 crores State wide media coverage

Minor 2 Medical treatment injuries Net negative financial impact of 0.5 – 1 crore Local stakeholder concern and public attention

Insignificant 1 First Aid treatment Net negative financial impact of <0.5 crores. No media coverage

Risk Evaluation Based on ranking of likelihood and frequencies, each identified hazard has been evaluated based on the likelihood of occurrence and the magnitude of consequences. The significance of the risk is expressed as the product of likelihood and the consequence of the risk event, expressed as follows: Significance = Likelihood X Consequence The Table 7.7 below illustrates all possible product results for the five likelihood and consequence categories while the Table 7.8 assigns risk significance criteria in three regions that identify the limit of risk acceptability. Depending on the position of the intersection of a column with a row in the risk matrix, hazard prone activities have been classified as low, medium and high thereby qualifying for a set of risk reduction / mitigation strategies.

Table 7.7 Risk Matrix

Likelihood

Frequent Probable Unlikely Remote Improbable 5 4 3 2 1

Con

sequ

ence

Catastrophic 5 25 20 15 10 5

Major 4 20 16 12 8 4

Moderate 3 15 12 9 6 3


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Minor 2 10 8 6 4 2

Insignificant 1 5 4 3 2 1

Table 7.8 Risk Criteria and Action Requirements

S.N. Risk Significance Criteria Definition & Action Requirements

1 High (16 - 25)

“Risk requires attention” – Project HSE Management need to ensure that necessary mitigation are adopted to ensure that possible risk remains within acceptable limits

2

Medium (10 – 15)

“Risk is tolerable” – Project HSE Management needs to adopt necessary measures to prevent any change/modification of existing risk controls and ensure implementation of all practicable controls.

3 Low (5 – 9)

“Risk is acceptable” – Project related risks are managed by well-established controls and routine processes/procedures. Implementation of additional controls can be considered.

4 Very Low (1 – 4)

“Risk is acceptable” – All risks are managed by well-established controls and routine processes/procedures. Additional risk controls need not to be considered

Consequence Analysis – Pipelines

Pipeline generally contains large inventories of oil or gas under high pressure; although accidental releases from them are remote they have the potential of catastrophic or major consequences if related risks are not adequately analysed or controlled. The consequences of possible pipeline failure is generally predicted based on the hypothetical failure scenario considered and defining parameters such as meteorological conditions (stability class), leak hole & rupture size and orientation, pipeline pressure & temperature, physicochemical properties of chemicals released etc. In case of pipe rupture containing highly flammable natural gas, an immediate ignition will cause a jet fire. Flash fires can result from the release of natural gas through the formation of a vapour cloud with delayed ignition and a fire burning through the cloud. A fire can then flash back to the source of the leak and result in a jet fire. Flash fires have the potential for offsite impact as the vapour clouds can travel considerable distances downwind of the source. Explosions can occur when a flammable gas cloud in a confined area is ignited; however where vapour cloud concentration of released material is lower than Lower Flammability Limit (LFL), consequently the occurrence of a VCE is highly unlikely. VCE, if occurs may result in overpressure effects that become more significant as the degree of confinement increases (Refer Figure 7.3).Therefore, in the present study, only the risks of jet fires for the below scenarios have been modelled and calculated.


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Figure 7.3 Natural Gas Release – Potential Consequences

[Source: “Safety risk modelling and major accidents analysisof hydrogen and natural gas releases: Acomprehensive risk analysis framework” - Iraj Mohammadfam, Esmaeil Zarei] Based on the above discussion and frequency analysis as discussed in the earlier section, the following hypothetical risk scenarios (Refer Table 7.9) have been considered for consequence analysis of the natural gas supply pipeline (8inch dia) of 0.45km length.

Table 7.9 Pipeline Risk Modelling Scenarios

Scenario Pipeline Accident Scenario

Design Pressure (bar)

Pipeline Temperature

Potential Risk

1 Natural Gas Supply Pipeline

Leak of 25mm dia

34.0 24°C Jet Fire


Leak of 50mm dia

34.0 24°C Jet Fire


Complete rupture

34.0 24°C Jet Fire VCE

The pipeline failure risk scenarios have been modeled using ALOHA and interpreted in terms of Thermal Radiation Level of Concern (LOC) encompassing the following threshold values (measured in kilowatts per square meter) for natural gas (comprising of ~95% methane1) to create the default threat zones:

Red: 10 kW/ (sq. m) -- potentially lethal within 60 sec;

Orange: 5 kW/ (sq. m) -- second-degree burns within 60 sec; and

Yellow: 2 kW/ (sq. m) -- pain within 60 sec.

For vapour cloud explosion, the following threshold level of concern has been interpreted in terms of blast overpressure as specified below:

Red: 8.0 psi – destruction of buildings;

1 https://www.naesb.org//pdf2/wgq_bps100605w2.pdf

http://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=18&ved=0ahUKEwjF7MiDttPRAhVCMI8KHd7aD6cQFghrMBE&url=http%3A%2F%2Fwww.springer.com%2Fcda%2Fcontent%2Fdocument%2Fcda_downloaddocument%2F9781848828711-c1.pdf%3FSGWID%3D0-0-45-862344-p173918930&usg=AFQjCNEaJklfYKl3fRUdi6xiRYeW-FJb2A


209

Orange: 3.5 psi – serious injury likely; and

Yellow: 1.0 psi – shatters glass

The risk scenarios modelled for natural gas pipeline has been presented below

Scenario 1: Natural Gas Pipeline Leak (25mm dia)

The jet fire threat zone plot for release and ignition of natural gas from pipeline leak of 25mm dia is represented in Figure 7.4 below.

Figure 7.4 Threat Zone Plot – Natural Gas Pipeline Leak (25mm dia)

Source: ALOHA THREAT ZONE: Threat Modeled: Thermal radiation from jet fire

Red : <10 meters --- (10.0 kW/ (sq. m) = potentially lethal within 60 sec)

Orange: 14 meters --- (5.0 kW/ (sq. m) = 2nd degree burns within 60 sec)

Yellow: 21 meters --- (2.0 kW/ (sq. m) = pain within 60 sec) The worst hazard for release and ignition of natural gas from the pipeline leak of 25mm dia will be experienced to a maximum radial distance of less than 10m from the source with potential lethal effects within 1 minute.


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Scenario 2: Natural Gas Pipeline Leak (50mm dia)

The jet fire threat zone plot for release and ignition of natural gas from pipeline leak of 50mm dia is represented in Figure 7.5 below.

Figure 7.5 Threat Zone Plot – Natural Gas Pipeline Leak (50mm dia)


Red : 17 meters --- (10.0 kW/ (sq. m) = potentially lethal within 60 sec)


Yellow: 37 meters --- (2.0 kW/ (sq. m) = pain within 60 sec) The worst hazard for release and ignition of natural gas from the pipeline leak of 50mm dia will be experienced to a maximum radial distance of 17m from the source with potential lethal effects within 1 minute. Scenario 3: Natural Gas Pipeline Rupture

The jet fire threat zone plot for release and ignition of natural gas from pipeline rupture (worst case) is represented in Figure 7.6 below.


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Figure 7.6 Threat Zone Plot – Natural Gas Pipeline Rupture


Red : 25 meters --- (10.0 kW/ (sq. m) = potentially lethal within 60 sec)


Yellow: 59 meters --- (2.0 kW/ (sq. m) = pain within 60 sec) The worst hazard for release and ignition of natural gas from the pipeline rupture will be experienced to a maximum radial distance of 25m from the source with potential lethal effects within 1 minute. For VCE modelled for catastrophic failure of natural gas pipeline onsite, the LOC level was never exceeded THREAT ZONE:

Threat Modeled: Overpressure (blast force) from vapor cloud explosion

Type of Ignition: ignited by spark or flame

Level of Congestion: uncongested

Model Run: Heavy Gas

Red : LOC was never exceeded --- (8.0 psi = destruction of buildings)

Orange: LOC was never exceeded --- (3.5 psi = serious injury likely)

Yellow: LOC was never exceeded --- (1.0 psi = shatters glass)


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For calculating the risk significance of natural gas pipeline, the likelihood ranking is considered to be “2” as the probability of pipeline rupture is computed to be ~2.88x10-5 per year; whereas the consequence ranking has been identified to be as “3” as given for a worst case scenario (rupture) lethal effects is likely to be limited within a radial zone of ~25m. Also no social sensitivities in the form of village settlements, educational institutions etc. were found to be located within this zone. Further as discussed in the earlier section, adequate number of gas leak and fire detection system of appropriate design will be provided for the pipeline supply of natural gas to prevent for any major risk at an early stage of the incident. Risk Ranking – Natural Gas Pipeline Rupture (Worst Case Scenario)

Likelihood ranking 2 Consequence ranking 3

Risk Ranking & Significance = 6 i.e. “Low” i.e. Risk is Acceptable and can be managed through use of existing controls and evaluation of additional controls.

7.1.7 Disaster Management Plan

Disaster Management is a process or strategy that is implemented when any type of catastrophic event takes place. The Disaster Management Plan envisages the need for providing appropriate action so as to minimize loss of life/property and for restoration of normalcy within the minimum time in event of any emergency. Adequate manpower, training and infrastructure are required to achieve this. The objectives of Disaster Management Plan are as follows:

Rapid control and containment of the hazardous situation; Minimising the risk and impact of occurrence and its catastrophic effects; Effective rehabilitation of affected persons and prevention of damage to Property and environment; To render assistance to outside the factory.

The following important elements in the disaster management plan (DMP) are suggested to effectively achieve the objectives of emergency planning:

Reliable and early detection of an emergency and careful response; The command, co-ordination, and response organization structure along with efficient trained personnel; The availability of resources for handling emergencies; Appropriate emergency response actions; Effective notification and communication facilities; Regular review and updating of the DMP; Proper training of the concerned personnel.

7.1.8 Emergency Identified

Emergencies that may arise:

Such an occurrence may result in on-site implications like :


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o Fire or explosion; o Leakage of natural gas. Incidents having off-site implications can be: o Natural calamities like earthquake, cyclone, lightening, etc. Other incidents, which can also result in a disaster, are : o Agitation / forced entry by external group of people; o Sabotage.

The Hazards Identification & Risk Assessment (HIRA), carried out in the existing Plant, emergency conditions are identified; and to prevent these emergencies, SHEOP are prepared.

Table 7.10 Emergency Conditions in the Plant

Sl. No.

Area Aspect/ Hazards Impact/ Risk

1. Hydrogen cylinder storage Jet fire, flash fire BELVE (fire ball)

Burn/ injuries

2. Chlorine tonner storage Toxic gas release Serious effect on health, loss of life and property inside and nearby society and impact on environment.

3. CO2 storage tank Toxic gas release Frost barite 4. NG pipeline Jet fire, flash fire/ VCE Serious injuries and

catastrophic event 5. Transformer oil storage and

transformer Pool fire Burn/ injuries

6. Lubricating oil storage Pool fire Burn/ injuries 7. Caustic soda container Corrosive Injuries 8. Sulfuric acid storage tank Corrosive Injuries 9. HCl storage tank Corrosive Injuries 10. Switchyard Fire Burn/ injuries 11. Boiler Explosion Injuries/ casualties

7.1.9 Emergency Classification

Due consideration is given to the severity of potential emergency situation that may arise as a result of accident events as discussed in the Risk Analysis (RA) study. Not all emergency situations call for mobilization of same resources or emergency actions and therefore, the emergencies are classified into three levels depending on their severity and potential impact, so that appropriate emergency response procedures can be effectively implemented by the Emergency Response Team. The emergency levels/tiers defined with respect to this project based on their severity have been discussed in the subsequent sections with 'decision tree' for emergency classification being depicted in Figure 7.7.


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Figure 7.7 Emergency Classification "Decision Tree"

The emergency situations have been classified in three categories depending upon their magnitude and consequences. Different types of emergencies that may arise at OTPC gas based power plant can be broadly classified as: Level 1 Emergency

The emergency situation arising in any section of one particular plant / area which is minor in nature, can be controlled within the affected section itself, with the help of in-house resources available at any given point of time. The emergency control actions are limited to level 1 emergency organization only. But such emergency does not have the potential to cause serious injury or damage to property / environment and the domino effect to other section of the affected plant or nearby plants/ areas. Level 2 Emergency

The emergency situation arising in one or more plants / areas which has the potential to cause serious injury or damage to property / environment within the affected plant or to the nearby plants / areas. This level of emergency situation will not affect surrounding community beyond the power plant facility. But such emergency situation always warrants mobilizing the


215

necessary resources available in-house and/or outsources to mitigate the emergency. The situation requires declaration of On – Site emergency. Level 3 Emergency

The emergency is perceived to be a kind of situation arising out of an incident having potential threat to human lives and property not only within the power plant facility but also in surrounding areas and environment. It may not be possible to control such situations with the resources available within OTPC power plant facility. The situation may demand prompt response of multiple emergency response groups as have been recognized under the off-site district disaster management plan of Gomati district.

7.1.10 Onsite Disaster Management Team & their Responsibility

Responsibility for establishing and maintaining record of disaster management belongs to Works Main Controller. He is responsible for distribution & control of the plan, and for ensuring that the plans are implemented, reviewed and revised annually. Incidence Controller is responsible for the training of personnel to ensure that adequate emergency response capabilities are maintained in accordance with the plan. Works Main Controller and Incidence Controller are responsible for ensuring the efficacy of the conduct of drills, as outlined in the DMP. All employees of various departments are responsible for carrying out their responsibilities, as defined in DMP. In order to handle disaster/emergency situations, an organizational chart entrusting responsibility to various site personnel has been prepared along with their specific roles during an emergency. The disaster management team OTPC-Palatana plant is given in Figure 7.8.


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Figure 7.8 OTPC Disaster Management Team

7.1.11 Emergency Resources Available

The DMP include emergency preparedness plan, emergency response team, emergency communication, emergency responsibilities, emergency facilities, and emergency actions.

Facilities and Resources during Emergencies

OTPC is maintaining the following facilities in a state of readiness with equipment to detect the emergency and respond effectively during any disaster. Emergency Control Centre (ECC)

It is a location, where all key personnel like Combat Team Leader, Rescue Team Leader and Auxiliary Team Leader, etc. can assemble in the event of onset of emergency and carry on various duties assigned to them. During an emergency, the Incident Controller including Combat Team Leader, Rescue Team Leader and Auxiliary Team Leader will gather in the ECC. Therefore, the ECC is equipped with adequate communication systems in the form of telephones and other equipment to allow unhampered communication with the teams involved in bringing the incident under control, and with the external response organisations and other nearby facility personnel. The ECC is always ready for operation and provided with the equipment and supplies necessary aids during the emergency such as:

Latest copy of the On-site Disaster Management Plan;


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Emergency telephone rosters; Factory Layout, Site Plan o Plans indicating locations of hazardous inventories, sources of safety

equipment, hydrant layout, location of pump house, road plan, assembly points, vulnerable zones, escape routes;

Emergency shut-down procedures; Nominal roll of employees; List and address of key personnel, Emergency coordinators, first aiders, firefighting employees.

Emergency Communication

The plant has Local Audio Alarm System, PA system, & Emergency siren with siren code to make the emergency known both inside and outside of the facility, and co-ordinating among the various groups involved in response operations. Warning/Alarm/Communication of Emergency: The emergency would be communicated by operating electrical siren for continuously for three minutes with high and low pitch mode. Personal Protective Equipment

This equipment is used mainly for three reasons: To protect personnel from a hazard while performing rescue/accident control operations, To do maintenance and repair work under hazardous conditions, and For escape purposes.

The list of Personal Protective Equipment provided at the facility and their locations are available in ECC. Fire Fighting Facilities

Internal hydrant system; Portable extinguishers.

Fire Protection System

These systems are available to protect the plant by means of different fire protection facilities and consist of

Hydrant system for exterior as well as internal protection of various buildings/areas of the plant. Portable extinguishers and hand appliances for extinguishing small fires in different areas of the plant. Water monitor will be provided in hypo plant area. Fire water pumps. Two (2) independent motor driven pumps each of sufficient capacity and head are proposed for the hydrant system which is capable to extinguish Fire or cooling purpose.


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Medical Facilities, Equipment and Supplies

Doctor and preliminary treatment facilities in the plant; Ambulance; and Mutual aid with nearby industries.

Emergency Escapes

The objective of the emergency escape is to escape from the hazardous locations, to the nearest assembly point or the other safe zone, for rescue and evacuation. Emergency escape routes have been provided within the plant. Wind socks are also provided in various locations. Emergency Transport

Emergency Ambulance is stationed at the main gate and round the clock-driver is available for emergency transportation of injured personnel, if any. The other vehicles of the company also would be available for emergency services. Security and Access Control Equipment

In case of an emergency the incoming response teams and resources will be directed to assembly place. Admission to contaminated area / effected area will be restricted. The response team and resources coming from outside will reach to event place after permission from Works Main Controller. Assembly Point

Assembly point is location, where, persons not-connected with emergency operations would proceed at assembly point and await for rescue operation. Emergency Power and Lighting

Plant has equipped with a Diesel generator sets, which are auto started on the loss of all On-site power to the primary bus. The DG set is sized to provide emergency lighting in required areas and to meet the requirement to run the essential service equipment and critical equipment to safety & environment including emergency siren. Mutual Aid

While necessary facilities will be made available and updated from time to time, sometimes, it may be necessary to seek external assistance; it may be from the neighbouring factories or from the State Government.


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Command, Co-ordination and Response Team

One of the most important objectives of emergency planning is to create a response organisation structure capable of being developed in the shortest time possible during an emergency. Command and control of an emergency condition, encompasses the key management functions necessary to ensure the least impact on environment, health and safety of employees, as well as the public living in the vicinity. These primary functions are summarised as follows:

Detection of the emergency conditions; Assessment of the conditions; Classification of emergency; Mitigation of the emergency conditions; Notification to management personnel; Notification to local, state, and government agencies; Activation and response of the necessary on-site and off-site support personnel; Continuous assessment and reclassifications, as necessary; Initiation of proactive actions; Aid to affected personnel; Recovery and re-entry.

The plant has well defined command co-ordination and response team (Figure 7.7) and their responsibilities are well defined. Emergency Training, Exercises, and Planned Maintenance

Training Program

Training is one of the basic components of disaster management. In principle, anyone who occupies a position within the disaster management plant organisation undergoes some kind of training, followed by refresher courses at periodical intervals. The main goal of training for emergencies is to enable the participants to understand their roles in the response organisation, the tasks associated with each position, and the procedures for maintaining effective communications with the other response functions and individuals. An in-house team will be appointed for the development of such training programme. This team is composed of the same people in-charge of developing and reviewing the response plan. Mock Drill

In spite of detailed training, it may be necessary to try out whether, the OSEP works out and will there be any difficulties in execution of such plan. In order to evaluate the plan and see whether the plan meets the objectives of the OSEP, periodical mock drills are contemplated. Before undertaking the drill, it would


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be very much necessary to give adequate training to all staff members and also information about possible mock drill. After few pre-informed mock drills, few un-informed mock drills would be taken. All this is to familiarize the employees with the concept and procedures and to see their response. These scheduled and unscheduled mock drills would be conducted during shift change, public holidays, in night shift etc. To improve preparedness once in 6 months mock drill will be conducted. Incident Controller (IC) coordinates this activity. PPEs In certain circumstances, personal protection of the individual maybe required as a supplement to other preventive action. It should not be regarded as a substitute for other control measures and must only be used in conjunction with substitution and elimination measures. PPEs must be appropriately selected individually fitted and workers trained in their correct use and maintenance. PPEs must be regularly checked and maintained to ensure that the worker is being protected.

7.2 PUBLIC CONSULTATIONS

7.2.1 Stakeholder Identification

Keeping in mind the nature of the project and its setting, the stakeholders have been identified and listed in the table given below.

Table 7.11 Stakeholder Group Categorization

Stakeholder Group Actual Stakeholders Community Local Community of surrounding villages Institutional Stakeholder Local Gram Panchayet of in Kakraban and

Matabari RD block Government Bodies Regulatory Authority such as TSPCB

District Administration (health, irrigation, employment exchange etc)

7.2.2 Stakeholder Consultation

Stakeholder consultation was carried out with the objective of finding out about their views and opinion on issues relating to the project, its operations and also to the peripheral development. The following table provides brief profiles of the various stakeholders in the project as discussed in the previous sub section along with their key concerns in association of the project.


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Table 7.12 Stakeholder Profiles and Opinions

Relevant Stakeholders

Profile/Status Concerns surrounding the project Expectations from the project

Local Community This stakeholder group is comprised of those individuals or groups who maybe directly or indirectly affected by the project.

The primary concern of the stakeholders pertaining to the project are as follows:

Increase pollution level due to discharge of water and noise

The main expectations of the stakeholders from the project are as follows:

Employment opportunities in the project Community development activities with an emphasis on infrastructure development and skill development for income generation

Local Gram Panchayet

The Panchayat is the lowest levels of local governance and consists of one or more revenue villages. The Gram Panchayats in the proximity of the OTPC plant

The main concerns of the stakeholder group are as follows:

Increase in pollution of water, noise, air and soil due to project activities Adequacy of the community development initiatives to be undertaken by the project Timely and adequate disclosure of information throughout the life of the project


Measures to prevent and reduce pollution Appropriate community development activities in keeping with the needs of the community Preference in employment opportunities for locals Involvement in the formulation of the community development activities and their implementation Timely disclosure of information through the life of the project

Regulatory Authorities

These stakeholder groups are defined as those agencies of the state and national government who have the power to regulate or otherwise influence the project in terms of establishing policy, granting permits and approvals for the project, monitoring and enforcing compliance with the applicable rules and regulations and making available the necessary infrastructure and resources for the project. These departments are also store house of relevant information both for the impact assessment as well as to help implement management plans.

The primary concern of the stakeholder group pertains to the project’s compliance towards the regulatory requirements.

The primary expectations of the stakeholder group from the project pertain to the following:

Compliance with the regulatory requirements specific to the project Timely disclosure of information and provisioning of updates through the life of the project


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Relevant Stakeholders

Profile/Status Concerns surrounding the project Expectations from the project

Some of the regulatory authorities likely to have an impact on the project include the Tripura Pollution Control Board

District Administration

The project area is administered by government bodies at three levels: at the district level, at the block level and at the Panchayat level in each village. The process of decentralisation has resulted in substantial decision making authority being vested in the district authorities with substantial funds being routed through them towards fund development. Accordingly, the bureaucracy under the Block Development Officers, Block Health Officer, District Education Officers, Gram Panchayet Pradhan and member become extremely influential

The primary concern of the stakeholder group pertains to the following:

project’s compliance towards the regulatory requirement role played by the project in the development of the area


Compliance with the regulatory requirements and legal provisions specific to the project Timely disclosure of information pertaining to the project activities Involvement in the formulation and implementation of the community development activities throughout the life of the project


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7.2.3 Public Hearing

Public Hearing for the project was conducted by Tripura State Pollution Control Board (TSPCB) at the OTPC Palatana Plant premises on 4th October 2018. Sri Animesh Das, Additional District Magistrate, Gomati District presided over the hearing. The local stakeholders were informed about the PH through notice in vernavular language (Bengali) and English Newspaper was published in four (04) daily newspaper on 30.08.2018 and 01.09.2018 (Refer Annex 7.1) by TSPCB. 231 people from nearby villages and representative from Civil Socity attended the PH meeting. Issues discussed during the Public Hearing by the locals and clarifications provided by the project proponent and action plan has been presented Table 7.13. The minutes of the PH issued by TSPCB has been provided in Annex G. The photographs of the PH are presented in Figure

Figure 7.9 Photographs of Public Hearing


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Table 7.1 Issues discussed during Public Hearing & Action Plan

S. No. Query / statement /information/ clarification sought at the venue of PH

Reply of the query/ statement/ information/ Clarification given by the OTPC

Action Plan along with Budgetary Allocation

1. Sri Nirmal Sarkar, Purba Palatana, 3 No. Ward: Sough for agricultural development in the area

OTPC agreed to assist, when the proposal sent through Gram Panchayat and Block Development Officer and if it falls under purview of CSR

Detailed CSR plan for the project has been developed in line with MoEF&CC latest OM No. 22-65/2017-IA dated 01.05.2018 and presented at the section 1 of the EIA report (Details of CSR section may be provided here)

2. Sri Mitan Das, Palatana Nayaghat stated that OTPC was constructed on Forest land, so OTPC should conduct compensatory afforestation at the community land

OTPC has developed 33% greenbelt in the plant area. However, OTPC can support the community plantation, if the villages provide land for the same.

OTPC will allocate the budget for community plantation under CER budget. Village wise and year wise budget will be formulated after receiving proposal from village with provision of land for the community plantation (Refer Annex E; CSR Plan)

3. Sri Bidhan Sarkar, Palatana enquired about the water discharged into the river generated by the plant

OTPC confirmed that no water will be discharged from proposed expansion unit. it is also stated that an approximate 5300 KLD treated water is being discharged from existing unit and water quality is being monitored through online monitoring system

OTPC will maintain the zero discharge for the proposed expansion unit (Refer Section 2.8.2). Periodical water quality monitoring of Gumti River will be carried out as per environmental monitoring Program (Refer Section 6.2 and Table 6.1)

4. Prabhat Nama, Palatana asked about the type of benefit that the people may get from the project.

OTPC stated that the nearby people may be benefited by getting work and business opportunity. They can also be benefitted by investment and electricity generation.

OTPC has developed a CSR Plan considering socio-economic consultation during EIA study and Public Hearing issues/ concern raised by the local community (Refer Annex E; CSR Plan). in line with MoEF&CC latest OM No. 22-65/2017-IA dated 01.05.2018 and presented at the section 1 of the EIA report (Details of CSR section may be provided here)Further OTPC in consultation with local Panchayat and administration will finalize the local people engagement plan and provision of economic opportunity during construction stage of the plant (Refer Section 9.3.10).


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5. Sri Bhabhananda Sen, Dudhpuskarini stated that they did not receive any benefit from the project located at Dudhpushkurini

OTPC has constructed Mid-day Kitchen room for Anganwari Centre and have carried out may job opportunities for the local people

OTPC has developed a CSR Plan considering socio-economic consultation during EIA study and Public Hearing issues/ concern raised by the local community in line with MoEF&CC latest OM No. 22-65/2017-IA dated 01.05.2018 and presented at the section 1 of the EIA report (Details of CSR section may be provided here) (Refer Annex E; CSR Plan).

6. Sri Paramanada Sen, Dudhpuskarini said that waste water discharged from the plant to nearby agricultural land and its productivity of Dudhpuskarini village. He requested to provide assistance for Diary development and help for BPL and APL students in schools.

Since the question is not related to OTPC and of Dairy unit established near to the concerned peoples agricultural field; therefore, Scientist C, Tripura State Pollution Control Board replied that The complaint regarding discharge of water into agricultural land will be verified and appropriate measures will be taken. Further, the project proposal were invited through proper channel with regards to the development works.

The effluent generated from the proposed expansion unit will be treated through ETP and RO. The treated water will be recycled and reused in cooling system and greenbelt plantation (Refer Section 9.3.5). A part of the treated effluent from the existing plant will be discharged into Gumti River after meeting discharge standard. OPTC also implementing the Rainwater Harvesting Plan and harvested rainwater will be pumped into Raw Water Reservoir. Implementation of rainwater harvesting scheme will minimise the discharge from the plant (Refer Section 9.3.6). OTPC had developed a CSR Plan considering socio-economic consultation during EIA study and Public Hearing issues/ concern raised by the local community and in line with MoEF&CC latest OM No. 22-65/2017-IA dated 01.05.2018 and presented at the section 1 of the EIA report (Details of CSR section may be provided here) (Refer Annex E; CSR Plan).

7. Sri Litan Dey, South Murapara stated that neither any boundary wall was constructed nor any sanitation facilities were provided in South Murapara School even application was made. He has sought for afforestation also in that area.

For developmental activity application may be made through BDO. OTPC can support the community plantation, if the villages provide land for the same.

OTPC has developed a CSR Plan considering socio-economic consultation during EIA study and Public Hearing issues/ concern raised by the local community (Refer Annex E; CSR Plan).


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8. Sri Sudhir Majumder, Mirza, 2 No. Ward demanded assistance for irrigation facility for 2000-2500 acres of land at Mirzapara

In response, the MLA and ADM informed that proposal for development of irrigation facility in the said area is in planning stage under the irrigation Department and water Resource Department. However, OTPC can take up those CSR activities, if it falls under the company policy.

OTPC will contribute a part in the irrigation project for Mirzapara area, if it is implemented under Govt. Scheme. The contribution amount will be decided after detailed discussion with District Administration.

9. Sri Subhra Das, Jampura requested to set up a water treatment plant in the village apart from providing Street light facility and improvement in the hospital.

The proposal for water treatment plant can be submitted through BDO. It was also stated that OTPC can install solar street lighting facility but community should take up the responsibility of maintenance because this facility has been taken up in other villages too, but most of them are not in working condition due to lack of maintenance.


10. A residence of Mugrapara village complained that local people are not included in the Project work as contractor even though they have skill and ability for the same.

The contractor must be registered in order to get the job.

11. A resident of South Mugrapara village enquired about impact on the plant and animals. He also asked about the possibility of involvement of Forest protection Committee members for protection of plants and animals. Further he also sought for Fishery Training.

The proposed expansion will be carried out within the existing plant area. said it was informed that Fishery Training Programme has been take up in other villages and hence this can be taken up in the present village too.


12. A resident asked about the views of OTPC regarding difficulty of setting up of Water Treatment Plant as informed by the Water Resource Department due to withdrawal of large volume of water from Gumti River by the project proponent.

It was stated that a comprehensive study was carried out by NIT Agartala. The annual requirement of the plant after expansion will be 12.51 million m3/ year, i.e. 1.14% of the total annual discharge.

NIT Agartala has conducted a detailed hydrological study to assess the impact on downstream users of Gumti River. The summary of hydrological study has been presented Section 7.4 of EIA & EMP report and Study report annexed in Annex C.


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7.3 BIODIVERSITY & ECOLOGICAL STUDY

As per approved ToR for the proposed expansion project, Bio-diversity and ecology impact assessment study for six months has been conducted with the involvement of experts specifically familiar with the biota of Tripura/north-east India through Centre for Environment and Development (CED), Kolkata. Two season (pre-monsoon and post-monsoon) ecological survey was conducted by CED team. The following ecological components were surveyed:

Ecological habitat in the 10 km study area; Sensitive ecological habitat; Terrestrial flora including the quantitative survey (transect and quadrant) Butterfly & moths (quantitative survey – quadrant) Mammals; Birds (quantitative survey – quadrant) Reptiles; Amphibians Fishes Planktons- Phytoplankton, and zooplankton in Gumti River Benthos in Gumti River

The ecological baseline survey and findling has been presented in Section 3.3. The detailed biodiversity ecology survey report of CED is attached in Annex B.

7.4 ECO-HYDROLOGICAL STUDY

As per approved ToR for the proposed expansion project, Eco-hydrology study assessing the impact of proposed water withdrawal from River Gumti on downstream biota, agriculture and domestic users has been carried out by engaging National Institute of Technology (NIT) Agartala.

To assess the available surface water resources in the study area; To identify the competing users of surface water resources in the study area; To assess the existing and future demand of water resources in the study area; To assess the impact on competing users of surface water resources due to additional water requirement for proposed expansion project. Two season (pre-monsoon and monsoon) discharge of the river –upstream and downstream of OTPC intake point; Surface water demand for lift-irrigation, water supply scheme, and domestic uses in the nearby villages; Other uses of river; Ground water uses and demand Drainage and surface runoff in the study area Climatological data.


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Water Availability of downstream users

The hydrology study report is prepared based on field experiment and field data obtained from different department and sources from 2011 to 2017. Based on the experiment and data evaluation, Gumti river water is sufficient to install the two new units of proposed capacity. Total discharge of the river Gumti near the intake point = 1096.32 million m3/year found out by using experimental data. Total water available in river Gumti after all the consumption and losses= 543.19 million m3/year.

OTPC Water Requirement Percentage of Total Available Water Existing water requirement 1.40% After Proposed Expansion 2.53%

The Eco-hydrological study reported prepared by NIT Agartala is attached at Annex C.

7.5 CSR PLAN

As per approved ToR, need based assessment study shall be conducted by an Institute of National Repute for implementing CSR.In order to validate and assess the CSR Programmes under CSR Policy, OTPC engaged ‘SoulAce’ – a specialized CSR organization to undertake the need based assessment study across the 10 villages situated at the periphery of the plant site and prepared the comprehensive report. Based on the outcome of the study, a five year CSR Action Plan for community development was prepared by SoulAce. The Action Plan encompassed a two-pronged approach encompassing ‘flagship initiatives’ and ‘short term projects’ for implementation of CSR interventions in the peripheral villages. As part of the CSR plan, 5 flagship initiatives and 15 short term projects have been proposed. Guidance map for identifying beneficiaries, selecting a CSR programme for implementation, collaborating with NGOs for programme implementation, programme implementation, monitoring of the CSR programmes and reporting of the CSR activities have also been proposed. Overall, the CSR Plan proposed by SoulAce was observed to align with the CSR Policy of OTPC. The report is attached in Annex D. As part of the EIA study, efforts were also made to assess the implementation status of the CSR plan. The ERM team conducted field visits in June 2017 to assess the CSR interventions in a sample of villages in Tripura where these interventions are currently being implemented. During the field visit, the following categories of stakeholders were consulted; (i) local youth; (ii) women; (iii) tribals; and (iv) officials of OTPC. Detail of CSR study and action plan for 19-20 to 202324 was prepared. The summary of proposed CSR interventions and budget is presented in 9.3.9. The report is attached in Annex E.


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8 PROJECT BENEFITS

The project involves expansion of existing 2 x363.3 MW gas based power plant within the existing industrial area of OTPC Palatana plant. The existing plant is operational since 2014 and has been beneficial with respect to supply of power share to Tripura state alongwith availability of physical and social infrastructure, livelihood generation and other benefits. This chapter presents the summary of the benefits due to the existing plant; the same benefits shall be extended to the proposed activity as well. Environmental Benefits

The existing and proposed expansion project to inject clean power into the grid, thereby reducing CO2 emissions and also results in coal resource conservation The existing project is registered as a CDM project with the United Nations Framework Convention on Climate Change (UNFCCC), under the Kyoto Protocol. Registered under fuel-substitution and mitigate over 1.6 million tons of CO2 emissions per year for the next 10 years. Being gas based project, it has the ability to have rapid ramp-up / ramp-down rate which helps in meeting fluctuations in the grid arising from RE injections.

Social Infrastructure

CSR activities in the area of education, community health, youth program, etc.

Employment & Business Opportunity

During the construction phase around 500 (during peak construction phase) workers will be required and during operation phase the project will generate additional direct employment for 80 people. The positives impact include enhanced direct employment for technical/ administrative works and indirect employment opportunities for transporters of construction materials; Increasing other business opportunities for local people as there will be scope of commercial establishments, local market centres, hiring vehicle like tractors & trolleys, JCB and other equipment during construction and operation phase of the project.

Other Tangible & Locational Benefits

Largest investment in the NER after independence (> Rs.10,000 Crores). It has helped reducing electricity deficit and stimulating economic growth in the NER. Power from the project is providing base load power to the NER and has helped in improving stability of power grids & energy security of the region.


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9 ENVIRONMENTAL MANAGEMENT PLAN

9.1 INTRODUCTION

The objective of the Environmental Management Plan (EMP) is to identify Project specific environmental actions that will be undertaken to mitigate and manage impacts associated with the proposed expansion project. The EMP focusses on potential impact and risks that have been identified as part of the Impact Assessment process. This EMP will be an overview document that will guide environmental management of all aspects of OTPC’s activities i.e. construction and operation of proposed expansion unit. The EMP describes the actions to be adopted in terms of: • National Policies and Regulations • Good Practices and guidelines • Local Environmental and Social Sensitivities

9.2 ENVIRONMENT MANAGEMENT FRAMEWORK AND PLAN

Various components of Environment Management Framework and the detailed plans are discussed in the sections below.

9.2.1 Organizational Role and Responsibility

Corporate Environmental Responsibility

OTPC recognises that a safe, healthy & environment friendly workplace along with environment, safety and health conscious personnel are core of driving the business sustainability. OTPC is committed to ensuring environmentally sustainable and responsible operations to achieve the highest standards of excellence. OTPC’s existing Palatana plant has not only instituted internationally accepted Environmental Management System based on ISO-14001, but the site has also integrated the same with Quality Management and Occupational Health & Safety Management Systems. The same shall be extended to the proposed project activity also. OTPC’s Environment Policy has been shown Figure 9.1 . The policy has been approved by the Managing Director of the company.


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Figure 9.1 OTPC's Environment, Occupational Health & Safety Policy

Organizational Structure and Responsibility

Role of OTPC OTPC will have ultimate responsibility for implementing the provisions of the EMP. This role will include the management of environmental impacts, monitoring of contractor performance as well as development of mechanisms for dealing with environmental problems. OTPC will also ensure that the activities of its contractors during construction phase are conducted in accordance with ‘good practice’ measures, implementation of which will be required through contractual documentation. In order to facilitate this, and to demonstrate commitment to the EMP, OTPC /Contractor will conduct regular internal site inspections, the results of which will be documented. The organisation structure of the OTPC is Figure 9.2.


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Figure 9.2 OTPC-Palatana EHS Organization Structure

Role of Contractors during construction phase

Contractors will also be expected to demonstrate commitment to the environmental monitoring program at all levels in the Contractor’s management structure. It will be ensured the following:

The contractors involved in the project will be responsible for implementation of, and adherence to, all the mitigation measures outlined in the EIA; Appropriately experienced and qualified personnel are employed as the Contractor’s Environmental Manager ; Reports on environmental incidents are submitted to OTPC-Palatana at the earliest; Appropriate mechanisms are developed and implemented for dealing with unforeseen events; A program of regular self-inspection and audit is developed and implemented and the results are reported to the OTPC-Palatana EHS Team on a regular basis All contractors will maintain records of regular inspection

Inspection, Monitoring and Audit

Inspection and monitoring of the environmental impacts of the project activities will increase the effectiveness of the EMP. Through the process of inspection and auditing, OTPC will ensure that the conditions stipulated in the Environmental Clearance (EC), Consent for Establishment (CTE), Consent to Operate (CTO), etc. are complied with. It is proposed that the audit will be conducted by Audit Team for implementation of management system. The entire process of inspections and audits will be documented and inspection and audit findings will be implemented by OTPC.


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Monitoring, Reporting and Documentation

OTPC will develop a well-documented reporting requirement for the all stages of the project with delegated personal to meet the reporting requirements and timely submission of all compliance reports. OTPC will hire an external agency to conduct monitoring for air emissions and discharge of effluent/ wastewater quality for submission to TSPCB/ RO-of MoEFCC. Records of all of the monitoring activities will be maintained and will be available for review as required by TSPCB/ CPCB/RO-of MoEFCC. Annual environmental report known as ‘Environmental Statement’ as per Form V of EPA Rules, 1986, six monthly compliance report as per EC of MoEFCC, compliance reports as per CTE/CTO etc. will be submitted to the regulatory agencies. The Manager (EHS) will be the responsible person for ensuring that communication with regulatory agencies is maintained as per the required norm. Internal Monitoring, Reporting and Communication

Internal monitoring will focus on measuring and reporting progress of implementing EMP activities. The Manager (EHS) will be responsible for internal monitoring. Inspection and audits finding along with their improvement program will be regularly reported to the senior management for their consideration. Documentation

Documentation is an important step in implementing the EMP. OTPC will establish a well-defined documentation and record keeping system to ensure recording and updating of documents as per the requirements specified in existing EMP. Responsibilities will be assigned to relevant personnel for ensuring that the EMP documentation system is maintained and that document control is ensured through access by and distribution to, identified personnel in form of the following:

Master Environment Management System document; Legal Register; Operation control procedures; Work instructions; Incident reports; Emergency preparedness and response procedures; Training records; Monitoring reports; Auditing reports; and Complaints register and issues attended/closed


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All the above documentation system will be maintained as per the requirement of TSPCB/MoEFCC and other relevant regulatory authorities. EMP Review & Amendments

The EMP would be reviewed periodically to update it addressing any changes in the organisation, process or regulatory requirements. Implementation

The implementation of EMP mainly comprises of making resources available for the project, accountability of contractors and documentation of measures to be taken. The Manager (EHS) has the overall mandate for coordination of the actions required for environmental mitigation and management and monitoring the progress of the proposed management plans and various action plans to be implemented for the project. The Manager (EHS) would be responsible for the following functions:

Preparation of required EMS documents; Ensuring availability of resources and appropriate institutional arrangements for implementation of EMP; Selection of appropriate MoEFCC/NABL approved monitoring agency for carrying out monitoring and analysis; Co-ordinating with monitoring agency in collection and analysis of water, air and soil samples, water samples, monitoring of noise levels within and outside the work zone; Implementation of the health and safety measures; Conducting routine medical check-up of workers; Green belt development; Co-ordination of the environment related activities within OTPC; Awareness and implementing environment and safety programmes; Providing job specific training; Compliance of regulatory requirements; Carrying out environmental audits; Monitoring the progress of implementation of EMP; and Reviewing and updating the EMP as and when required for its effective implementation.

9.3 ACTION PLANS UNDER EMP

Environmental Management Plans have been prepared based on the outcome of Environmental Impact Assessment study. These EMPs apply to project activities of OTPC. The commitments made in these plans are applicable to OTPC and its contractor personnel. The principal purpose of formulating this EMP is to ensure commitments made in the EIA report are translated into ongoing actions.


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Objectives

The objectives of the EMPs are to: Describe the approach and procedures that will be adopted in execution of the project; Achieve the intended objectives of the proposed project and also of the mitigation measures thereby reducing the environmental impacts to the levels predicted in the EIA; Ensure compliance in respect of the project’s legal, regulatory and policy obligations.

Various action plans developed under EMP for implementation during construction and operation phases are given below:

Air Quality Management Plan Noise Quality Management Plan Solid and Hazardous Waste Management Plan Storm Water Management Plan Waste Water & Effluent Management Plan Water Conservation and Rainwater Harvesting Plan Greenbelt Plan Occupational Health & Safety Management Plan Socio-economic Management Plan.

9.3.2 Air Quality Management Plan

Construction Phase

The major impact on ambient air quality during construction phase would be from operation of machineries and vehicles, earth work at site, construction material transport, storage and handling of construction materials, disposal of construction and demolition waste, operation of DG sets for emergency power supply, etc. Mitigation Measures

The following mitigation measures will be taken to control/reduce / mitigate fugitive and gaseous emissions during the construction phase. Regular Maintenance of Vehicle and Machineries

All vehicles utilized in transportation of raw materials and personnel, will have valid Pollution under Control Certificate (PUCC). Vehicular exhaust will be complying with the CPCB specified emission norms for heavy diesel vehicles;

Regular maintenance of machines, equipment’s and vehicles that will be used for construction activities.

Dust Suppression Measures

The storage of construction material such as cement, sand aggregates etc. will be covered;


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The manual handling of the raw material (loading and unloading) will be minimized to reduce the dust exposure; Vehicles loaded with construction materials shall be covered with tarpaulin sheets; The site approach road will be maintained to minimize emission; Housekeeping of the site will be regularly carried out to minimize the fugitive emission from material handling areas, internal roads and construction waste storage areas;

Monitoring

Periodic monitoring of ambient air quality near sensitive receptors locations (Refer. Environmental Monitoring Program A-1.1) Periodic stack monitoring of DG sets to check compliance to emission standards specified by CPCB as per Environmental Monitoring Program (Refer. A-1.1).

Operational Phase

Operational phase air quality impacts will be from stack emission from power plant unit and back up DG. Other emissions are vehicular emission from transport of manpower to plant. Control/ Mitigation Measures

The following control/mitigation measures will be taken to control/reduce / mitigate fugitive and stack emissions during operation of plant. Control of Air emission from boiler Control of NOx and PM emission: The source of NOx emissions are from gas based power plant (Refer: Section 2.10.1; Table 2.10.1-Potential Pollutants and Control Measures for Operational of Plant). To control the NOx and PM emission following control measures will be taken.

The proposed plant will be utilising Dry Low NOx / equivalent burners to minimize the NOx emission to a level less than stipulation by CPCB/ MoEFCC. Natural gas is a clean fuel and the fuel used is filtered in multi stages and hence the flue gas coming out of stack in the combined cycle modes of operation will have low level of particulate matter. Stacks having sufficient heights as per statutory norms to ensure dispersion of pollutants; Port holes and sampling facilities will be provided in stacks; Continuous Emission Monitoring System (CEMS) will be provided for stackes; All the units will have to be maintained / operated properly at optimum efficiency.


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Control of emission from DG set: The emission from DG sets will be controlled by the following measures:

Stacks having sufficient heights as per statutory norms to ensure dispersion of pollutants; Port holes and sampling facilities will be provided; DG sets will have to be maintained / operated properly at optimum efficiency.

Control Vehicular Emission:

All vehicles utilized in transportation of raw materials and personnel, will have valid Pollution under Control Certificate (PUCC). Vehicular exhaust will be complying with the CPCB specified emission norms for heavy diesel vehicles; The site approach road will be maintained to minimize emission;

Monitoring:

Continuous emission monitoring (CEM) for the measurement of air emission levels in the stacks; Periodic monitoring of stacks through third party NABL/MoEFCC approved laboratories; Regular monitoring of ambient air quality near sensitive receptors locations as per Environmental Monitoring Program (Refer. Section B.1.5)

Executive- Env. & Chemistry of the plant will be responsible for implementing the plan during both construction and operational phases under the guidance of Manager (EHS).

9.3.3 Noise Quality Management Plan

Construction Phase

Noise will be emitted from construction site during site preparation, construction activities, movement of vehicles and construction machineries, operations of DG sets. Noise during the site preparatory phase will primarily be contributed by heavy construction machinery operating on site and vehicular sources. Noise Abatement

Construction equipment generating minimum noise and vibration will be selected; Periodic preventive maintenance of operational units will be undertaken in accordance to supplier/manufacturer manual;

Provision of PPE

Personnel deployed near high noise generating areas will be equipped with proper PPEs (ear plugs etc.) and subjected to rotation. Periodic health surveillance programs to be organized to monitor the health of workers.


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Monitoring

Periodic monitoring of ambient noise quality near sensitive receptors will be undertaken to ensure compliance with regulatory standards as specified under the Environmental Monitoring Framework (Refer. Section A.1.3). Periodic work place noise will be monitored in all the noise generating sources as specified under the Environmental Monitoring Framework (Refer. Section A.4.1).

Operational Phase

Operational Phase noise would be generated from operation of boiler, turbine, compressor, pumps, other machineries, movement of vehicles, back up DG sets. The noise emission control/mitigations measures are as follows: Noise Abatement for Plant & Machineries

Acoustic laggings and silencers, sound proofing/ glass panelling etc. will be provided at critical operating locations. Selection of the new equipment’s will be made with specification of low noise levels, wherever possible. Regular maintenance of machinery will be undertaken to mitigate the noise generation. The existing maintenance schedule will be extended to the proposed project activity also.

Noise Abatement for Transport Vehicles

Only those vehicles meeting the standards as specified by Bureau of Indian Standards for Noise Emitted by Moving Vehicles 2012 will be used; Vehicles should be regularly maintained.

Provision of PPE Personnel deployed near high noise generating areas will be equipped with proper PPEs (ear plugs etc.) and subjected to rotation. Periodic health surveillance programs to be organized to monitor the health of workers.

Monitoring

Periodic monitoring of ambient noise quality near sensitive receptors will be undertaken to ensure compliance with regulatory standards as per the Environmental Monitoring Framework (Refer. Section B.4.3). Periodic work place noise will be monitored in all the noise generating sources as per the Environmental Monitoring Framework (Refer. Section B.4.3).

Executive- Env. & Chemistry and Manager EHS O&M Contractor of the plant will be responsible for implementing the plan during both construction and operational phases under the guidance of .


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9.3.4 Solid and Hazardous Waste Management Plan

The solid waste management plan establishes specific measures to ensure proper collection, storage, treatment and disposal in accordance with the applicable national regulations and guidelines. Construction Phase

Construction Waste: The following measures will be taken for managing the construction waste:

The construction waste will be stored at designated waste storage areas; The storage areas to be properly bunded and provided with garland drains and silt traps; Construction waste will be utilized in the backfilling of the low-lying area of the plant.

Municipal Solid Waste

Two bin collection system will be provided for collection of bio-degradable and recyclable waste; Organic/inert waste will be disposed in the Udaipur Municipal– MSW dumping site; Recyclable waste will be disposed through recycler.

Used Oil & Other hazardous Waste

The used oil will be stored in properly labeled and covered bins located in paved and bunded area; Necessary spill prevention measures viz. spill kit will be made available at the waste oil storage area; The used oil so stored to be periodically sent to registered recyclers.

Monitoring & Record Keeping Storage details of used oil generated will be maintained and periodically updated; Proper manifest as per HWMH rules to be maintained during storage, transportation and disposal of hazardous waste.

Operational Phase

Hazardous Waste Management There will be increase in the quantity of hazardous waste generation, due to proposed project activities. The existing facility has efficient hazardous waste management practices, which is in compliance to the Hazardous Wastes (Management, Handling and Transboundary Movement) Rules, 2016. Dedicated hazardous waste storage facility is available in the plant. Same facility will be utilized for the proposed project. The treatment and disposal of hazardous waste is presented in Table 9.1.


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Table 9.1 Hazardous Waste Management

Sl. No. Description Management Practices 1. Used oils No treatment at site. Sold to re-processor

(treatment at registered re-cycler/re-processor) 2. Discarded Containers, (used for

storing hazardous chemicals) Sold to recycler

3. Spent Resin Disposed through TSPCB approved vendor 4. Waste residues containing oil (oily

cotton rags, oily residues in waste oil etc.)

Disposed through TSPCB approved vendor

5. ETP Sludge Disposed through TSPCB approved vendor

Municipal Waste Management The existing sources of municipal wastes are from OTPC Staff Colony, Workers Colony, and Plant. The wastes are collected in segregated manner. The recyclable wastes are sold to recyclers. The biodegradable and inert wastes are disposed in the solid waste dumping site of Udaipur Municipal area. The similar practice will be continued for the proposed expansion unit. Monitoring & Record Keeping

Storage details of used oil generated will be maintained and periodically updated; Proper manifest as per HWMH rules will be maintained during storage, transportation and disposal of hazardous waste. Quantity of waste generated from the process will be maintained; quality of the waste (brine sludge) will be periodically analyzed and record will be maintained. Contamination from waste handling, if any will be monitored through monitoring of soil and ground water quality as per Environmental Monitoring Framework (Refer. Section B.1.1).

Executive- Env. & Chemistry and Manager EHS O&M Contractor of the plant will be responsible for implementing the plan during both construction and operational phases under the guidance of Manager -EHS.

9.3.5 Waste Water & Effluent Management Plan

Construction Phase

Sewage from labour camps • The major source of waste water generation from construction phase is

domestic waste water from labour camp. The waste water generated from the site will be treated through septic tank and soak pit.

• Regular supervision will be undertaken for the domestic waste treatment system to report any overflows, leakage, foul odour etc.


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Operational Phase

Effluent from Plant: Total effluent generated from the plant (Phase I) is 5858 m3/day. The effluent is being treated in the ETP; part of the treated effluent (1000 m3/day) is being used for landscaping & greenbelt and balance water (4858 m3/day) is being disposed in the Gumti River after meeting discharge standard. Approximately, 5808 m3/day process effluent will be generate from the proposed expansion units (Phase II). The effluent will be treated through ETP. After treatment 3792 KLD of treated water will be recycled back to clarified water system. The balance 2016 KLD treated water will be utilised in greenbelt plantation and horticulture purpose. Phase II plant will be operated as zero discharge. The following control /mitigation measures will be taken for waste water and effluent management. • All the effluent generated from process will be channelized to ETP for

treatment; • Treated effluent will be utilised in the process and plantation purpose. The

plant will maintain the zero discharge for proposed expansion unit. • Water audits will be carried out periodically and recommendations for

recycling / conservation will be implemented; • A logbook of ETP and STP operation that contains the quantity of effluent,

generated, reused/recycled, utilized in plantation/gardening, etc. will be maintained as per the existing practice;

• The performance of the ETP and STP will be evaluated periodically. Monitoring and Record Keeping

Quality of untreated and treated effluent will be periodically monitored as per Environmental Monitoring Program (Refer Section B.6.3) Domestic waste Water management

• The major source of waste water generation is from Staff residential colony, Workers Colony and Plant office building etc. The waste water generated from these sources will be treated through ETP. The treated water will be utilised in the plantation purpose.

• Regular supervision will be undertaken for the domestic waste treatment system to report any overflows, leakage, foul odour etc.

Executive- Env. & Chemistry and Manager EHS O&M Contractor of the plant will be responsible for implementing the plan during both construction and operational phases under the guidance of Manager -EHS.


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9.3.6 Storm Water Management and Rainwater Harvesting Plan

The Storm Water Management Plan (SWMP) refers to the proper management of surface run-off generated for various parts of the plant. Surface run off from construction material and waste storage areas, hazardous waste (used oil, etc.) and chemical storage areas may lead to the pollution of receiving natural drainage channels and adjacent agricultural land. This situation is likely to be more pronounced considering high rainfall received by the area. The surface run off could contain high sediment load, chemicals, etc. This may have adverse impact on water quality, which ultimately leads to impact on aquatic ecology. Rainwater Harvesting

OTPC has engaged FICHTNER Consulting Engineers (India) Private Limited for preparation of Rainwater Harvesting Scheme 12.. As per scheme, OTPC is now implemented the scheme. As per Rainwater harvesting plan; it was estimated that yearly 1267042 m3 of surface runoff water is likely to be harvested from the project site. In the rainwater harvesting plan, it is proposed that the harvested water will be channelized to storm water drains and then storm water pits through recharge pit then desilting tank. In the plan, it was proposed to construct four (4) rain water harvesting pits. The size of the pits are as follows:

SWP-1: 1653.68 m3 SWP-2: m3 SWP-3: m3

m3 The collected rain water will be pumping to raw water reservoir for process use. The schematic diagram of rainwater harvesting system is presented in Figure 9.3 The net capacity of the existing raw water reservoir is 1,81,197 m3. In the project area, the runoff is likely to be collected within the plant area is about 10440 m3/hr. During rainy season, raw water reservoir with 2/3 of capacity can handled additional 6 hours continuous rainfall within the plant boundary. At the same time, water withdrawal from external source shall be reduces based on the availability of water in the reservoir. The Rainwater Plan is attached in Annex F.


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Figure 9.3 Schematic Diagram of Rainwater Harvesting System

Mitigation Measures

Additional drainage structures will be created at the construction material handling site. Necessary measures will be undertaken during construction phase to prevent earth and stone material from blocking cross drainage structures. Periodic cleaning will be undertaken of storm water drainage structures to maintain uninterrupted storm water flow. Sediment control measures in the form of silt traps and sedimentation tank will be provided to treat surface run-off before disposal. Oil water separator will be provided in the oil handling/ storage sites; Perform regular sweeping of work areas in the plant.

Monitoring: Surface water quality will be monitored in the Gumti River as per Environmental Monitoring Program (Refer Section B.6.3).


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Executive- Env. & Chemistry and Manager EHS O&M Contractor of the plant will be responsible for implementing the plan during both construction and operational phases under the guidance of Manager EHS.

9.3.7 Occupational Health & Safety Management Plan (OHSMP)

The Occupation Health & Safety Management Plan (OHSMP) is applicable for all project operations which have the potential to adversely affect the health and safety of contractors’ workers and onsite OTPC personnel. In addition to the OHSMP, OTPC operations will also be governed by the health and safety provisions of Factories Act, 1948. The OHSMP has been formulated to address the occupational health and safety related impacts that may arise from proposed project activities viz. operation of construction machinery/equipment, storage and handling of fuel and chemicals, operation in plant, etc. Construction Phase

Training programs will be conducted for the workforce regarding proper usage of Personal Protection Equipment (PPE)s, handling and storage of fuels and chemicals, etc. No employee will be exposed to a noise level greater than 85 dB (A) for a duration of more than 8 hours per day. Provision of ear plugs, ear muffs etc. and rotation of workers operating near high noise generating areas. Hazardous and risky areas, installations, materials, safety measures, emergency exits, etc. will be appropriately marked. Adequate sanitation facilities will be provided onsite for the construction workers.

Operations Phase

Hazardous and risky areas, installations, materials, safety measures, emergency exits, etc. will be appropriately marked. No employee will be exposed to a noise level greater than 85 dB (A) for a duration of more than 8 hours per day. Provision of ear plugs, ear muffs etc. and rotation of workers operating near high noise generating areas. All chemicals and hazardous materials storage container will be properly labelled and marked. Materials Safety Data Sheets (MSDS) or equivalent data/information in Bengali will be readily available to exposed workers and first-aid personnel. The workplace will be equipped with fire detectors, alarm systems and fire-fighting equipment. Equipment will be periodically inspected and maintained to keep good working condition. Worker will be adequately trained on correct use of machinery and safety devices. Safety instructions and cautionary signage will be displayed near each machinery; Installation of mechanical lifting aids; arrangement of fall arresting equipment;


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Availability of walkways to separate people from vehicles or moving parts to reduce risk of collision; Installation of localized exhaust ventilation to remove dust and other pollutant from work areas; Develop and implement permit to work system for critical activities viz. height work; confined space entry; electrical work, etc. Restrict access to confined spaces and other high risk areas; Training programs will be conducted for the operational workforce regarding proper usage of PPEs, handling and storage of fuels and chemicals, etc. PPE will be inspected regularly and maintained or replaced as necessary; Adequate sanitation facilities will be provided onsite for the operational workforce. Health problems of the workers will be taken care of by providing basic health care facilities through medical centre to be constructed during operational phase. Periodical health surveillance program will be implemented for all the workers in the plant and examination records will be maintained. Garbage bins will be provided in the plant and the garbage disposed of in a hygienic manner.

In addition to the aforesaid measures OTPC will be develop and implement a written fire safety plan that covers all the actions that workers and personnel must take to ensure occupational safety in the event of boiler explosion and fire (Refer. DMP). Occupation Health and Safety Facility

Medical surveillance refers to administrative and clinical procedures relevant to the supervision of health of workers. OTPC has well led down health monitoring and surveillance program for all the workers. Every employee on his appointment for a job will get a pre-employment medical examination before employment. Periodical medical check-up once in year has been carried out for all the workers as per Factories Act. The periodical health check-up has been carried out for Blood test, Renal Function test, Liver Function test, Urine, Pulmonary Function test, ECG, X-ray for Chest, Vision test, Audiogram test. There is Health Centre within the plant; permanent doctor, nurse, pharmacist in the health centre. Under periodical health check-up program, health check-up was carried out for 74 workers in 2016-17. The annual budget for occupational health surveillance and medical unit is about INR 77.12 lakh.


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9.3.8 Greenbelt Plan

Objective

The OTPC Palatana plant is spread over 197.15 acres of land. Area under Phase I plant is approximately 54.4 acre; non-plant building and road area is 51 acres. OTPC has earmarked 69 acres for greenbelt development. Implementation Strategy

Status update Based on the current greenbelt layout map, OTPC has developed 69 acres for greenbelt development.

Improvement of existing plantation area It is proposed to improve the greenbelt plantation within the project site with plantation of pollutant (PM, NOx) tolerant plant species recommended for industrial areas. The existing plant list of floral species within the OTPC plant indicates the presence of about 25 plant species. Recommended new plant species to be planted within the existing and future greenbelt areas are listed in Table 2.16. The existing and proposed plantation map is presented in Figure 2.21. Plantation Community Land: OTPC will provide sapling to the schools, and panchayat for plantation. OTPC will supply 2000 sapling to the local people. The preferred species will be fruit trees and timber plant.

Table 9.2 Recommended Plant Species for Greenbelt with the Plant

Plant Species Ailanthus excelsa Diasporus melanoxylon Moringa oleifera Butea monosperma Madhuca indica Shorea robusta Citrus medica Mimusops elengi Tamarindus indica Clerodendron infortunatum Holoptelia integrifolia

Follow up Action

The following actions apply to habitat conservation program within OTPC project site:

Planting of pollutant tolerant species to replace lost recruits if the rate of loss is higher than the rate of establishment; Continue monitoring of the growing plants and maintain a flexible approach.

Monitoring Parameters and Timing

The following actions apply to habitat conservation program within OTPC project site:


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Continue monitoring of the growing plants and maintain a flexible approach.

Plantation maintenance Clearing other vegetation: It is important to clear or cut the unnecessary vegetation “weed”, or the disturbing vegetation at least twice a year. This action will allow the seedlings to grow without competing with other trees that may cause mortality. The vegetation is not removed from the sites and serves as natural mulch. Selecting trees that should be removed: It is necessary to perform selected cutting in order to keep a healthy growth and to maintain an optimal distance for canopy expansion and to build enough space for the growing mature trees. The selected cutting is usually conducted when the plantation is 3 (three) years old. After that, no cutting is done nor required. Replanting Replacing the dead trees with the new seedlings will be conducted at least twice a year to allow a stable high density of trees in the field.

9.3.9 Wildlife Conservation Plan

Species Conservation Program

59 species of butterflies including few threatened species are reported from the study area. Butterfly is being an environmental indicator the following conservation plans are suggested for enhancement of the overall diversity of the butterfly fauna of the study area:

Within the power plant complex/ township area, the project proponent should develop Butterfly Park in consultation with Forest Department. The project proponent should also identify some of the nearby schools and colleges (4-5) and encourage and support them to develop gardens within the premises with some ornamental woody shrub species as well as the host plants, which would attract and support diverse butterflies.

Habitat Improvement Program for mammals & birds

There are four Reserve Forests in the study area. The project proponent should support the Forest Department for habitat improvement. The following program should be taken in consultation with Forest Dept.:

Gap plantation with wild tree and woody shrubs need to be planted to improve the habitat quality; The tree species like Terminalia bellerica, Gmelina arborea and Garuga pinnata and all the Ficus species such as: Ficus benghalensis, F. hispida, F. racemosa, F. religiosa, and F. glomerata, F. infectoria, and F. cunia reported in the region should be preserved/planted as the food resources of herbivore animals. Open areas within the forest land should be developed as grass patches to support herbivore mammals.


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Capacity Building of Forest Department Staffs

Workshops on forestry and biodiversity to be arranged for the forest department staffs for capacity building. External experts to be engaged for coordinating the workshops. It is planned to conduct one workshop per year. Each workshop would be for 1 day. One external expert should be engaged for coordinating the workshop. The main themes that the workshops should focus are;

Forest habitat protection and improvement Wildlife laws and their implementation Protected species in the area, their distribution, habitat, threats and conservation measures Human animal conflicts and management measures

The workshops would involve interactive sessions, video shows, poster presentation on forestry and biodiversity management. Case studies, success stories for forest management in India and abroad would also be discussed. The workshops would be conducted within the OTPC premise or any other venue as suggested by the Forest Department. Awareness Generation Meetings at Villages

The villagers, school children, industry workers working in the vicinity are to be made aware about the importance of wildlife, its habitat, importance of conservation, etc. OTPC will also conduct awareness campaigns at the village level to make the locals aware about the protected species in the area; their behaviour, habitat, ecology, breeding/nesting seasons, threats to habitats and species, laws regarding protection of species. Awareness generation campaigns will include preparation of brochures in local language, film shows and display of posters, etc. Forestry week, Wildlife week, Environment Day, Earth Day could be celebrated with the targeted group. It is planned to conduct one awareness generation campaign per year.

9.3.10 Socio-economic Management Plan

Mitigation measure have been outlined to address project related social issues and concerns in order for OTPC-Palatana to take proactive steps and adopt best practices, which are sensitive to the socio-cultural setting of the region. The plans will include people residing in proximity to the plant. Providing Job & Economic Opportunities

During site construction non- technical jobs will be generated. Most of the people employed during this stage would be semi-skilled or unskilled. People from adjoining areas especially given preference through local contractors according to the skill sets possessed. The following strategies shall be a part of the recruitment strategy:

The sourcing of local labour wherever possible should be obligatory;


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There should be a skill development program for a one to two year period to enable the local communities to benefit from the incremental workforce requirement during the operations phase; All contractors and sub-contractors during the construction and operations phase will require having local employment commitments and will document their compliance to labour laws including non-tolerance towards child labour and forced labour. OTPC in consultation with local Panchayat and administration will formulate local people engagement for job and economic opportunity during construction stage of the plant.

Corporate Social Responsibility

From inception of its activities OTPC-Palatana has taken up various CSR initiatives in the study area for the benefit of the residents as per the CSR Act and Rules, Govt. of India. The broad areas to be focused under the CSR plan will include:

Livelihood initiatives: Industrial training; Training support for skill development among women; providing vocational skill improvement training like- tailoring classes for village women for employment generation; employment generation scheme for disable persons ( Mobile Repair, Beautician Course, Tailoring centre), Employment generation scheme for fishery training (through Govt. Fishery Dept.) Health & sanitation- upgradation of existing medical units of OTPC, Provisioning of deployment of doctor on a weekly basis at 3 health centres in the study area and Providing ambulance services in the peripheral villages. Education - Providing financial assistance to educational institutions towards educational programs- mid-day mill facilities in the school, internet-enabled computers with curriculum based learning programmes; scholarships to economic backwardness of the students; infrastructure improvement work across the identified schools; maintenance of toilets: in Aanganwadi centres; renovation of kitchen sheds; Providing bicycles to children in schools, etc. Social infrastructure initiatives: Construction of bus shelters in villages; providing infrastructure of crematorium in the identified villages; construction of community hall in the identified villages; construction work of low cost toilets; expanding the Accelerated Rural Water Supply Scheme (ARWSS) in collaboration with the government, etc. CSR Plan- OTPC will consult District Administration, Panchayat and NAC for preparation of need based CSR and community engagement plan that will be implemented in a phase wise manner. This study will include:

o Need assessment in the villages; o CSR plan in consultation with local people, panchayat, district

authority, NGO & CBO; o Community engagement plan for implementation of CSR plan.

After formulation of Plan, company will implement the CSR plan through NGO/CBO.


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CSR Plan 2019-20 to 2023-24

Based on review of the CSR Plan, assessment of its status of implementation and discussions with local communities and representatives of the CSR department of OTPC, the following CSR interventions are proposed. The details CSR Plan is provided in Annex D.


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Table 9.3 CSR activity and budget for 2018-19 to 2021-22

S. L. Name of the CSR activity Budget details Budget (In Lakhs)

Implementation Plan (in Lakh) 2019-20 2020-21 2021-22 2022-23 2023-24

A. Health Initiatives 1. Medical unit inside the plant may be

upgraded into a 3 – 5 bedded intermittent treatment centre or equivalent medical support in Palatana Govt. hospital

Rs. 10,00,000 10.0 5.0 5.0

2. Provisioning of deployment of doctor on a weekly basis at Palatana Health Centre and two other identified buffer zone villages.

Rs. 5,000 for one doctor per week i.e. Rs. 20,000 per month (@ Rs. 20,000 x 12 months x 5 years x 3 health centre)

36.0 7.2 7.2 7.2 7.2 7.2

3 Providing ambulance services in the peripheral villages.

Rs. 60,000 for one ambulance per month i.e. Rs. 7,20,000 per annum.

36.0 7.2 7.2 7.2 7.2 7.2

B. Education interventions 4 Constructing cement slabs for mid-day

meals: for remaining 4 schools in the core zone and another 10 schools in the identified buffer zone villages

Rs. 50,000/- per school x 14 schools

7.0 1.4 1.4 1.4 1.4 1.4

5 Provide internet-enabled computers with curriculum based learning programmes installed to schools

Rs. 100,000 per school x 20 schools

20.0 4.0 4.0 4.0 4.0 4.0

6 Providing scholarships to economic backwardness of the students

Rs. 10,000 per student x 20 students per year x 5 years

10.0 2.0 2.0 2.0 2.0 2.0

7 Setting up of the English Medium School Rs. 100 lakh 100 20 20 20 20 20 8 The infrastructure improvement work

across the identified schools in the 15 villages

Rs. 100,000 per school x 15 schools

15.0 3.0 3.0 3.0 3.0 3.0

9 Maintenance of toilets: in 20 Aanganwadi centres

Rs. 25,000 per Aanganwadi centre x 20 centre

5.0 1.0 1.0 1.0 1.0 1.0

10 Renovation of kitchen sheds: Apart from construction of new kitchens at 15 Aanganwadi centres, renovation work of the 33 Aanganwadi centres

Construction of new kitchen – Rs. 1.0 lakh x 15 Aanganwadi centres Renovation work- Rs. 50,000 x 34 Aanganwadi centres

32.0 6.4 6.4 6.4 6.4 6.4

11 Providing bicycles to children in schools: Bicycles need to be provided to children of 20 schools

Rs. 2500 per bicycle x 50 bycles per year x 5 years

62.5 12.5 12.5 12.5 12.5 12.5


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S. L. Name of the CSR activity Budget details Budget (In Lakhs)

Implementation Plan (in Lakh) 2019-20 2020-21 2021-22 2022-23 2023-24

C. Livelihood initiatives 12 Industrial training: Collaboration efforts

with the Skill India Mission Programme Rs. 1.0 lakh per student x 2 years program x 10 selected students x 5 years

100.0 20.0 20.0 20.0 20.0 20.0

13 Training support for skill development among women: The programme may be continued to cover more women beneficiaries under the skill development programme

Rs. 25,000 per training program x 10 training programs in a year x 5 years

12.5 2.5 2.5 2.5 2.5 2.5

D. Social infrastructure initiatives 14 Construction of bus shelters in villages

Palatana, Khilpara and Udaipur and 5 additional sheds in the buffer zone villages

Rs. 1.0 lakh per facility x 8 facilities

8.0 1.6 1.6 1.6 1.6 1.6

15 Providing infrastructure of crematorium in village Jamjuri and another 2 villages in the buffer zone

Rs. 2.0 lakh per unit x 3 unit 6.0 2.0 2.0 2.0

16 Providing infrastructure of the graveyard in Dudpuskorini GP and 4 other grave yards in the buffer zone villages

Rs. 2.5 lakh x 5 graveyards 12.5 2.5 2.5 2.5 2.5 2.5

17 Construction of community hall in village 5 core zone villages and other 5 villages in the buffer zone

Rs. 5.0 lakhs per community hall x 10 community halls in 10 villages

50.0 10.0 10.0 10.0 10.0 10.0

18 Construction work of low cost toilets Rs. 10,000 contribution from OTPC per toilet x 50 toilets per year x 5 years

50.0 5.0 5.0 5.0 5.0 5.0

19 Expanding the Accelerated Rural Water Supply Scheme (ARWSS) in collaboration with the government to villages that are not covered under the scheme.

Lump sum Rs. 250 lakhs 250.0 50.0 50.0 50.0 50.0 50.0

20. Other CSR initiatives (livelihood and social infrastructural projects) identified during detailed CER /CSR planning

Total budgeted amount- 72.5 72.5 14.5 14.5 14.5 14.5 14.5

Total 895 177.8 175.8 172.8 170.8 172.8


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9.4 EMP IMPLEMENTATION BUDGET

EMP budget has been prepared considering 30-33 months of construction phase. EMP budget during operation phase has been prepared for 5 years period. The indicative EMP implementation budget is provided in Table 9.4.

Table 9.4 EMP Implementation Budget for Construction & Operational Phase

Sl. No. Particular of Works Budget (Lakh) A. Construction Phase 1. Air quality management plan a. Regular Maintenance of Vehicle and Machineries (periodical

maintenance budget of vehicles and machineries is part of contractor’s budgets)

0.00

b. Dust Suppression Measures i. Covered/enclosed storage area for construction materials

(budgetary provision is included in civil construction cost) 0.00

c. Monitoring i. Ambient Air Quality Monitoring -5 monitoring location x 2 weeks

per location x 3 seasons per year x 3 years of construction period (@ Rs. 7000 x 20 samples per quarter x 9 quarter)

12.60

ii. DG set stack monitoring- 1 samples x 12 quarters during construction period (@3000 x 12 samples)

0.36

2. Noise quality management plan a. Noise abatement (budgetary provision is included in civil

construction cost) 0.00

b. Provision of PPE to construction workers (budgetary provision is included in civil construction cost)

0.00

c. Monitoring i. Periodic monitoring of ambient noise quality – 5 locations around

the site (@ Rs. 2000 x 5 locations x one time in a season x 12 seasons during construction phase)

1.20

ii. Work Place noise monitoring – 3 locations in the construction site (@Rs. 1500 x 3 location x 33 months)

1.5

3. Solid and hazardous waste management a. Storage and disposal of construction site as per plan (budgetary

provision is included in civil construction cost) 0.00

b. Storage and disposal of MSW as per plan (budgetary provision is included in civil construction cost)

0.00

c. Storage and disposal of hazardous waste as per plan (budgetary provision is included in civil construction cost)

0.00

d. Monitoring and record keeping of generation and disposal 0.00 4. Waste water and effluent management plan a. Provision of septic tank and soak pit in the labour camp (budgetary

provision is included in civil construction cost) 0.00

5. Storm water management plan a. Periodical maintenance of storm water drains and sedimentation

tank (@ Rs. 50,000 per year x 3 years) 1.5

b. Monitoring i. Surface water quality 3 locations (@ Rs. 7000 x once per season x 4

seasons x 3 years) 2.52

6. Occupational health & safety management a. Provision of PPE to the workers (Refer 2.b) 0.00 b. Provision of sanitation and drinking water at labour camp and

construction site (budgetary provision is included in civil construction cost)

0.00

Total Implementation EMP Implementation Budget during construction phase

19.68

B. Operational Phase 1. Air quality management plan


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Sl. No. Particular of Works Budget (Lakh) a. Operation and maintenance of low NOx burner for control of NOx

emission and continuous online stack monitoring (budgetary provision is included in operation of plant & machineries)

0.00

b. Operation of boiler and back up DG sets to control air emission (budgetary provision is included in operation of plant & machineries)

0.00

d. Monitoring i. Periodical ambient air quality monitoring – 5 locations x 2 times in

a week x 54 weeks per year (@ Rs. 7000 x 104 samples per location x 5 year)

182.00

ii. Periodical stack monitoring by third party- three stacks (2 expansion unit and 1 DG) (@ Rs. 3000 x 3 stacks x once per season x 4 seasons x 5 year)

1.80

iii. Installation of online monitoring system for two expansion units 80.0 iv. Installation of continuous online monitoring system for ambient air

air quality monitoring (3 sets) 210.0

2. Noise quality management plan a. Noise abatement for plant & machineries (budgetary provision is

included in operation of plant & machineries) 0.00

b. Provision of PPE (@ Rs. 2 lakhs per year x 5 years) 10.0 c. Monitoring i. Periodic monitoring of ambient noise quality – 5 locations around

the site (@ Rs. 2000 x 5 locations x one time in a season x 3 seasons per year x 5 years)

1.50

ii. Work Place noise monitoring – 4 locations in the plant (@Rs. 1500 x 4 location x 4 seasons x 5 years)

0.90

3. Solid and hazardous waste management a. Storage and disposal of hazardous waste from the plant (budgetary

provision is included in operation of plant & associated facilities) 0.00

b. Storage and disposal of non-hazardous waste from the plant (budgetary provision is included in operation of plant & associated facilities)

0.00

c. Collection, storage and disposal of MSW (periodical replacement collection bins and transport of MSW into disposal site) (@ Rs. 25,000 per month x 5 years)

15.00

d. Monitoring i. Monitoring of ground water -5 locations (@ Rs. 7000 per samples x 4

samples per season x 3 seasons /year x 5 years) 4.20

ii. Monitoring of soil quality – 3 locations (@ Rs. 7000 per samples x 3 samples per season x 3 seasons /year x 5 years)

3.15

4. Waste water and effluent management plan a. Operation and maintenance of ETP (budgetary provision is

included in operation of plant & associated facilities) 0.00

b. Maintenance of Guard Pond (budgetary provision is included in operation of plant & associated facilities)

0.00

c. Periodical maintenance STP (budgetary provision is included in operation of plant & associated facilities)

0.00

5. Storm water Management a. Periodical maintenance of storm water drains and sedimentation

tank (@ Rs. 100,000 per year) 5.00

b. Monitoring i. Surface water quality 3 locations (@ Rs. 7000 x once per season x 4

seasons x 5 years) 4.20

6. Occupational health & safety management a. Provision of PPE and periodical replacement (@ Rs. 3.0 lakhs per

year) 15.00

b. Periodical health check-up of the workers (@ Rs. 7.0 lakhs per year) 35.00 7. Water conservation and Rainwater harvesting plan a. Rainwater harvesting measures (maintenance of check-collection

pit) 2.50


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Sl. No. Particular of Works Budget (Lakh) 8. Greenbelt plantation and maintenance (@ Rs. 5,0 lakhs per year) 25.00 9. Wildlife Conservation Plan a. Species conservation program

Butterfly park with the plant/ township area Butterfly park in the schools/collage (3 nos.)

8.0

b. Cost of Habitat Improvement (Contributing Forest Departments habitat improvement program; Plantation and conservation of keystone species and Incentive to local people towards conserving biodiversity)

17.5

b. Cost of capacity building of forest department staffs (Engagement of external expert; Logistic cost for arrangement of workshop; Cost of development of IEC Material)

4.50

c. Awareness Generation Meetings at villages (Development of Brochure; Arrangement of Meeting; Development of Posters)

7.25

Total EMP Budget for Environment & Biodiversity 632.5 10. Socio-economic management plan & CSR Activity a. Health Initiatives 82.0 b. Education interventions 251.5 c. Livelihood initiatives 112.5 d. Social infrastructure initiatives 449.0 Total CSR Budget 895.0 Total EMP Implementation Budget for Operation Phase 1527.5


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10 SUMMARY AND CONCLUSION

OTPC intends to expand the capacity of gas based thermal power plant from 2 x 363.3 MW to another 2 addiional units. The proposed project activities will be carried out within the existing plant premises. Resource requirement

Land: proposed expansion unit will be constructed within the plant of OTPC-Palatana plant. Water: Additional 20,400 M3/day water will be required for proposed expansion unit, and it will be sourced from Gumti River. Natural Gas: The annual average consumption of the gas will be (considering 85% PLF) 1260 Million SCM. Per day estimated gas for base load at design site ambient condition is about 2.70 to 3.30 MMSCMD. Manpower: The existing manpower for the plant is 155. After expansion, total man power requirement will be approximately 235 numbers. Baseline environment summary

The baseline data obtained by primary monitoring/survey and review of secondary information has been summarized below:

Land use The predominant land use-land cover of the study area includes rubber plantation (37.72%), agricultural land (27.48%), settlement & homestead plantation (22.75%), natural forest (10.36%), river (0.86%), waterbody (0.25%), etc.

Soil quality pH varies from 4.8 to 6.15. Organic carbon contents varied between 0.36-0.7 mg/kg. The available NPK content varied between 134 to 268 mg/kg; <3 to 6.5 mg/kg and 30 to 40 mg/kg respectively. The level of metal contents in the soil : iron level - 61 mg/kg to 280 mg/kg, coppr - 4.4 mg/kg to 14.0 mg/kg, lead - 5.2 mg/kg to 10.0 mg/kg; chromium - 10 mg/ to 22 mg/kg and Cadmium - 2 mg/l.

Ambient air quality

PM10, PM2.5, NOx, SO2, CO, O3 and Hg were well within the NAAQS. HC in ambient varies from 1.21ppm and 1.80ppm.

Noise quality

Day time and noise time noise quality in all the monitoring locations were within the ambient noise quality standard for residential area. The noise level in the plant area is also noise quality standard for industrial area.


The surface water samples were collected from Gumti River and river water was in compliance to the criteria for propagation of fish and wildlife (Class D).


pH varies from 5.61 to 8.13. The level of dissolved solids in the groundwater samples (28-150 mg/l) were found to be below the acceptable limit of IS 10500 standards i.e., 500 mg/l. The chloride concentration in the ground water samples (13.7-59 mg/l) was found to be in compliance to the acceptable limit. Total hardness in the groundwater samples varied from 19.6 mg/l to 88.0 mg/l and were incompliance to the acceptable limit of 200 mg/l. Concentration iron in ground water sample ranged from <0.05-0.43 mg/l. Iron concentration in all the samples were in compliance to the acceptable limit (0.3 mg/l) of IS:10500 standards excepting the sample collected from Gangachara village (0.43 mg/l). Mercury, cadmium, lead, zinc and


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chromium contents in all ground water samples were found to be below detection limits.

Biological environment

The study area has natural ecosystem like forests, rubber plantation, homestead plantation, riparian jungle besides the river and stream. The Trishna wildlife sanctuary is located around 9.17 km from the plant.

Socio-economic environment

The project footprint spread across 32 census villages. The major occupations in the study area are agriculture, wage labour, service, etc.

Impact assessment and mitigation measures summary

The EIA study has been undertaken to assess the potential significant adverse environmental impacts due to the proposed expansion activities. Mitigation measures have been proposed as part of EMP to minimize adverse environmental impacts, if any.

Environmental component

Impact description Impact significance

Mitigation measures

Construction Phase Ambient air quality

Fugitive emission from storage and handling construction materials, and emission from vehicles & machineries

Minor Dust suppression measures- covered storage, maintenance of site approach road.

Noise quality Operation of vehicles & machineries

Minor Engineering control to minimise the noise of machineries and vehicles.


Due to surface runoff from construction site and construction material handling site during monsoon season

Minor Spill control in construction site, treatment of surface runoff sedimentation chamber


Contamination of ground water from spillage of oil & lubricant, etc.

Minor Control of spill and disposal of construction waste and MSW in designated disposal site.

Ecology and biodiversity

Disturbance due to noise and illumination

Minor Control the air and noise emission from construction site.


Beneficial impact due to employment generation and economic opportunity

Positive Provide job preference to the local people.

Operational Phase Ambient air quality

Emission of NOx and PM from gas based power plant

Moderate Control of NOX through low NOX burner.

Noise quality Emission of noise from plant and machineries

Minor Engineering control to minimise the noise emission from plant and greenbelt around the plant.


Effluent generation from plant, surface runoff from plant

Moderate Treatment of effluent in ETP and reused and recycled within the plant; treatment of domestic waste water through STP; treatment of surface runoff through sedimentation tank.

Surface water resources

Sourcing of ground water 18,650 KLD for proposed expansion unit

Moderate Water conservation measures – zero discharge,


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Environmental component

Impact description Impact significance

Mitigation measures

rainwater harvesting and utilization in the process.


Potential to impact on ground water from waste disposal site, spillage of chemical and oil handling site

Minor Storage of hazardous waste and disposed through waste handlers, spill control measures.

Ecology & biodiverse

Air emission from plant, noise generation from plant, surface runoff from plant area and illumination from plant

Moderate Emission control, noise control, treatment and reuse & recycle of treated water; disposal of solid waste; greenbelt.


Beneficial impact due to employment generation and economic opportunity

Positive Provide job preference to the local people.

Risk assessment includes leakage and rapture of natural gas pipeline resulting pool fire. The existing Emergency Management Plan of OTPC-Palatana plant will be extended to this project and implemented in the event of any emergency arising due to above mentioned risks. Project Benefit

The benefits due to the existing plant and proposed expansion projects are as follows:

Clean fuel based power generation, thereby reducing CO2 emissions and also results in coal resource conservation CSR activities in the area of education, community health, youth program, etc. Direct and indirect employment and business opportunity during construction phase and operational phase Largest investment in the NER after independence (> Rs.10,000 Crores). It has helped reducing electricity deficit and stimulating economic growth in the NER. Power from the project is providing base load power to the NER and has helped in improving stability of power grids & energy security of the region.

Conclusion

The present impact assessment study indicates that the overall impact from the proposed expansion project will be localised and are not expected to contribute significantly to the surrounding environment. Also, with the implementation of the pollution control and strengthen the existing environment management measures, these anticipated impacts due to construction and operation of the proposed project will be mitigated. OTPC-Palatana will also ensure that the environmental performances of all the activities are monitored throughout execution of the project during both construction and operation phase. Monitoring will include quantification of


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hazardous waste generated during construction phase, noise generated due to construction activities, etc. Similarly, during operation phase monitoring will be carried out for stack emission, quality of treated effluents, noise levels, hazardous waste generated and disposal, etc. as presently being followed and verify that they meet the prescribed standards. OTPC will continue to report environmental performance and monitoring reports regularly to statutory authorities. OTPC-Palatana plant has been in operation since 2015. Over the years, plant has developed systems and procedures for effective environmental management. The effective management system coupled with monitoring of environmental components and efforts for continual improvements will result in exemplary environmental performance.


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11 DISCLOSURE OF CONSULTANTS

Environmental Resources Management (ERM) is the world’s leading provider of environmental, health, safety, risk, social consulting and sustainability related services. With a history that spans more than four decades, ERM today has a global footprint of 160 offices in 40 counties, employing more than 5000 best-in-class professionals. In the last three years, ERM has worked with more than 50% of the Global Fortune 500 Companies. ERM India Private Limited (ERM India) was formally established in 1995 with its headquarters in Delhi and regional office in Mumbai (Maharashtra), Bangalore (Karnataka), Ahmadabad (Gujarat) and Kolkata (West Bengal). The contact address of ERM India is as follows: ERM India Private Limited Building No.10 Tower A, 4th Floor DLF Cyber City Gurgaon -122002 India Tel:+91-124-4170300; Fax: +91-124-4170301

11.1 ERM’S ACCREDITATION AS EIA CONSULTANT

ERM has been accredited as EIA consultant for various sectors including Thermal Power Plant sector from National Accreditation Board for Education and Training (NABET) of Quality Council of India (QCI) under the Accreditation Scheme for EIA Consultant Organisation as per the requirement of MoEFCC. ERM’s NABET Certificate No. NABET/EIA/1619/ RA 0055 issued on June 21, 2017 and valid up to October 31, 2019. The copy of NABET certificate is attached in Figure 11.1.

11.2 EIA TEAM

Declaration by Experts contributing to the EIA of Proposed Expansion of OTPC Palatana at Gomati district of Tripura. I, hereby, certify that I was a part of the EIA team in the following capacity that developed the above EIA. EIA Coordinator: Name: Salil Das Signature and Date 20 February 2019


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The professionals that were engaged for this study included in Table 11.1.

Table 11.1 Professionals Engaged for the EIA Study

S.N Functional Area

Name of the Expert

Involvement Signature & Date

1 Air Pollution

Dr. Debanjan Bandyopadhyay

Selection of air quality monitoring stations, discussion with client on various air pollution control aspects, inputs for impact assessment from the proposed project and development of EMP.

2. Water Pollution

Dhritiman Ray Selection of water monitoring stations, interpretation of analysis results, , inputs for impact assessment and development of EMP,

3. Air Quality Modelling

Naval Kishore Chaudhary

Modelling. Model input data related to emissions and micrometeorology interpretation of modelling results and development of EMP

4. Noise Quality

Naval Kishore Chaudhary Avijit Ghosh

Undertaking Noise Quality Modelling; Selection of noise sampling locations for baseline monitoring, model input data, interpretation of modelling results and development of EMP.

Left the organisation

5. Solid & Hazardous Waste

Dr. Koel Kumar Review of existing SHW management and support for impact assessment, and development of EMP.

Left the organisation

6. Socio-economic environment

Tufail Khan Souvik Basu

Support for socio economic baseline, stakeholder consultations and impact assessment.

7. Ecology and Biodiversity

Salil Das Dr. Abhishek Roy Goswami

Ecological survey and assessment of flora and fauna and related impact assessment and development of EMP.

8 Land use Dr. Debanjan Bandyopadhyay Dibyendu Chakraborty

Preparation of all maps including LU/LC and impact assessment.

9. Risk Assessment

Dr. Debanjan Bandyopadhyay

Technical review of the report and review of RA


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I, Neena Singh, hereby, confirm that the above mentioned experts prepared the EIA of Expansion of OTPC Palatana Plant at Udaipur district of Tripura. I also confirm that the consultant organization shall be fully accountable for any misleading information mentioned in this statement. Signature: Name: Neena Singh Designation: Managing Director Name of the EIA consultant organization: ERM India Private Limited Date: 20 February 2019


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Figure 11.1 NABET Certificate

Documents

Environmental Impact Assessment of (2 x 363.3 MW) +15% Gas …€¦ · Harnessing solar power within the premises of the plant particularly at available roof tops and other available