Leachate Basic Design[1]

KHANH HOA PROVINCIAL PEOPLE’S COMMITTEE

PROJECT MANAGEMENT UNIT (PMU) NHA TRANG

NHA TRANG ENVIRONMENTAL SANITATION PROJECT

Package NT6.20.1 (Phase 2)

FEASIBILITY STUDY

COMPONENT 3 – SOLID WASTE MANAGEMENT

ANNEX 2 – BASIC DESIGNDESIGN FOR IMPROVING LEACHATE TREATMENT PLANT

Nha Trang ESP FS Component 3 – Phụ lục - 5/2010PMU Nha Trang Fichtner GmbH & Co. KG

JUNE - 2010

TABLE OF CONTENTS

TECHNICAL DESCRIPTION................................................................................................................. 1

I. DESIGN TASKS............................................................................................................................ 1

I.1 DESIGN BASIS........................................................................................................................ 1

I.2 INFLUENT PARAMETERS......................................................................................................1

I.3 LEACHATE CONSTITUENTS.................................................................................................2

I.4 DESIGN SCOPE...................................................................................................................... 3

I.5 THE ITEMS OF DESIGN..........................................................................................................3

I.6 TECHNICAL SPECIFICATION................................................................................................3

I.7 LEGAL BASIS.......................................................................................................................... 3

II. DESCRIPTION OF TECHNICAL PROCESS ................................................................................3

II.1 THE BASIS OF TECHNICAL SELECTION.............................................................................3

II.2 THE ITEMS OF LEACHATE TREATMENT STATION/ PLANT..............................................4

II.3 DESCRIPTION PROCESS......................................................................................................5

III. UNIT WORKS DIMENTION..............................................................................................................8

IV. INVESTMENT COST ESTIMATION ...............................................................................................9

IV.1 CONSTRUCTION WORKS....................................................................................................9

IV.2 EQUIPMENTS AND STEEL UNIT WORKS........................................................................10

IV.3 TOTAL INVESTMENT COST ESTIMATION OF IMPROVING LEACHATE TREATMENT 13

V. OTHER RELATED ISSUES............................................................................................................13

V.1 OPERATION COST..............................................................................................................13

V.2 SOME MAIN ASSURANCE BIND TO CONTRACTOR........................................................14

VI. CONCLUSION............................................................................................................................... 14

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TECHNICAL DESCRIPTION

I. DESIGN TASKS

I.1 DESIGN BASIS

- Engineering geological Documents of Project site;

- Hydrologic and Geologic Documents of Project site;

- Influents parameters of leachate, including flow rate, influent characteristics and

requirement of effluent quality.

I.2 INFLUENT PARAMETERS

I.2.1 CALCUALTION OF LEACHATE FLOWRATE

I.2.1.1 Annual rainfall

According to Statistic in Nha Trang city, the average rainfall is 1746 mm (6-year

statistics from 2003 – 2008).

Jan Feb Match April May June July Aug Sep Oct Nov Dec Yearly

Average month

40,2 17,8 57,1 35,8 135,9 49 41,3 56,78 220 419,8 418,5 254,2 1746

The months with the high rainfall from September to December, average 325

mm/day.

I.2.1.2 Leachate flowrate at Luong Hoa Landfill and Ru Ri dumpsite

Luong Hoa Landfill

According to landfill design, all leachate which is generated will be stored within

landfill, and collected to treatment station in accordance with design capacity

average year. Storing leachte with a long time in landfill greatly contribute to

decompose organic matters which are created by acid phase and reduced organic

concentration (BOD5 và COD) at input of leachte treatment station/ plant. Daily

evaporation is estimated 0.5 mm in the dry season (due to without water on the

landfill surface) and about 1.5 mm in the rainy season (due to having more water on

surface in this season).

Total area of the rainwater square by land filling period is 3 hectares. Thus, the total

rainfall will be changed into leachate with an average capacity 119m3/day (see

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calculations in annex).

Leachate generated by the organic matters will enter the reaction, calculated by the

following formula:

Leachate + organic matters (CaHbOcNdSe) CO2 + CH4, partly of evaporation due to

generation of saturation moisture releases out of landfills. Estimation the amount of

leachate arised mainly from organic matters approx 280ton/ day x 5% total solid

waste = 14m3/day.

Thus, the total leachate generated from Luong Hoa Landfill = 119+14=133m3/day.

Ru Ri dumpsite

According to design of closing Ru Ri dumpsite, leachate will be completely separated

from overflow from the creek to dumpsite. The dumpsite will be designed and built up

final cover to limit soaking form stormwater after closing. Estimate of diffluence

coefficient is 0.7. Thus, it is only 30% of stormwater soaking into dumpsite to change

into leachate.

With the same description which be mentioned above, excluding the evaporation,

there is no generation of young leachate from solid waste. The total area of rainwater

square is 6 hectares. Thus, the flowrate generated after closing Ru Ri dumpsite is 36

m3/day.

All leachate from Ru Ri will be transported to Luong Hoa Landfill to treat together

with the one generated from this area.

I.2.2 TOTAL OF DESIGN FLOW OF LEACHATE

Total leachate will be treated at Luong Hoa Landfill is: 133 + 36 = 169m3/day. The

treatment station/ plant will be designed with safety factor 10%. The total of design

flow: 169m3/day x 1,1=186m3/day.

I.3 THÀNH PHẦN NƯỚC RÁC

Leachate was stored around 9 months (270days) in the landfill, then treated when

the operation is stable. Thus, the leachate compositions with parameters showed in

Table 1.1, as follows:

Table 1.1 Influent parameters and effluent standard

No. PARAMETERS UNIT INFLUENT EFFLUENT

(COLUMM B2 –

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QCVN 25:2009)

1 Flow Q m3 186 -

2 pH - 6,5 – 8,5 -

3 BOD5 mg/l 1000 50

5 COD mg/l 4000 300

6 NH4 - N mg/l 1200 25

Source: Main Report - Feasibility Study FS3 – Comp.3 – Solid waste Management, 2010

I.4 DESIGN SCOPE

To design leachate treatment station/ plant of Luong Hoa Landfill, capacity 186 m3/

day.

I.5 THE ITEMS OF DESIGN

- To design constructions for leachate treatment;

- Electrical system, lighting, lighting protector;

- Automatic control system for controlling leachate treatment station/ plant;

- Auxiliary construction such as internal roads, lawns, trees.

I.6 TECHNICAL SPECIFICATION

- Technology and equipments must be suitable with leachate characteristics and

Luong Hoa Landfill condition;

- System must be operated automatically;

- Operation is simple;

- The low operation and maintenance cost;

- The low investment and treatment cost;

- Effluent meet standard QCVN 25:2009, column B2.

I.7 LEGAL BASIS

The design of the project is carried out in accordance with Vietnamese environment

criteria and standards in terms of technology and environmental management:

- 22-TCN 225-95- Road Vehicles, Inspection process of engineering safety and

environmental protection.

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- TCVN 5948: 1999- Acoustic - Noise emitted by accelerating road vehicles -

Permitted maximum noise level.

- TCVN 5949-1998- Acoustics - Noise in public and residential areas- Maximum

permitted noise level

- TCXDVN 261-2001- Landfill- Standard for design

- QCXDVN 01: 2008/BXD- Vietnam Building Code – Regional and Urban Planning

and Rural Residential Planning.

- QCVN 25: 2009/BTNMT - National Technical Regulation on Wastewater of the

Solid Waste Landfill Sites

II. DESCRIPTION OF TECHNICAL PROCESS

II.1 THE BASIS OF TECHNICAL SELECTION

Referencing input data of leachate treatment and experience in landfill operation of

the provinces in The South of Vietnam showed that: leachate is difficult to handle

even using Physicochemical process, biological combined with high load process, If

not using proper technology. Nitrogen removal is one of other problem if not using

appropriate technology.

According to design of the treatment plant in phase 1, the processing steps are

mainly anaerobic lake, aerobic lake and plantation pond. This is a three treatment

steps of biological process with foible is difficult to achive organic concentration of

QCVN 25:2009, column B. The second foible is not removed Nitrogen concentration

to meet the above standard. One other weakness is the ability to emit odour in

anaerobic lake (Lake 1).

II.2 THE ITEMS OF LEACHATE TREATMENT STATION

Thus, to solve the foibles of the proposed treatment process in phase 1, the design

which is selected to improve leachate treatment station is the appropriate technology

with using the existing works and the lowest investment, at the same time minimizing

operating costs and as well as achiving standards. Improved process technology is a

combination of physicochemical and biological process to treate leachate to meet the

current standards.

LEACHTE TREATMENT STATION OF LUONG HOA LANDFILL IN NHA TRANG

CITY WITH CAPACITY 186 M3/ DAY with the main construction as follows:

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- Pre-treatment: including collection pit and the lime mixing tank. Leachate is

collected and stabilized on influent concentration.

- Stripping Tower 2 levels: for the treatment of NH3-N in leachate. The

equipments in the tower operate or stop automatically under the operation of

pump which pump waste water to the tower.

- Physicochemical tank: Using the aluminum alum flocculation to settle the

matter suspended within the leachte and partly colourity processing.

- Biological Lake Systems I, II and III: be used to thoroughly treated pollutants

composition within leachate before discharging into receiving body. These unit

works are being constructed in part and continue to improve by the Investment

Project, phase 1. Dimension of the biological lakes is presented in Table 1.2.

Table 1.2 The unit works are anticipated to invest in phase 1.

No. Name of unit work Capacity The state

01 Lake 1 15.000 (m3) Under-construction



06 2 aerator (90 kg/O2/h) 45 KW/motorBe anticipated to purchase

- Sludge treatment system: excess sludge from the physiochemical treatment is

pumped into the sludge tank. Sludge from sludge tank is collected and

transported to the cell of landfill.

- Chemical preparation system: including the chemical mixing equipment, tanks,

chemical pumps.

- Gas distribution system and blowers (fan and aerator) for Stripping towers and

biological lakes I and II.

- The pumps system of fresh leachate from collection pit, sludge pumps.

- The dosing pumps system to lime mixing tank, neutralization tank.

- Automatic control systems: including electrical control system and display panel

- The measuring equipments in the field include: pH meter, DO, flow.

Thus, the component of design constructions leachate treatment will be based on the

existing ones and add new unit works to optimize the quanlity of effluent and

investment cost.

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II.3 DESCRIPTION OF TECHNICAL PROCESS

The technical process is showed at Figure 2.1. The relative drawings see at

annexes.

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II.3.1 TECHNICAL PROCESS

Hình 1.1 Technical process of leachate treatment

NaOH PUMP HOLE 3

Polymer, HCl

RECEIVING BODY

(COLUMN B2

QCVN 25:2009/BTNMT)

WATER LINE

SLUDGE LINE

GAS LINE

CHEMICAL LINE

THE RAW LEACHATE COLLECTION PIT

LIME MIXING TANK

STRIPPING TOWER 1

STRIPPING TOWER 2

FLOCCULATION TANK

AEROBIC LAKE I

AEROBIC LAKE II

PLANT LAKE III

PUMP HOLE 1

PUMP HOLE 2

Ca(OH)2

Al2(SO4)3SLUDGE TANK

LANDFILL

LEGENDS

TECHNICAL LAYOUT OF LEACHATE TREATMENT STATION

CAUSTIC TANK

NaOH

II.3.2 DESCRIPTION OF TECHNICAL PROCESS

Leachate from Luong Hoa Landfill and Ru Ri dumpsite will be led to collection pit

500m3 at leachate treatment plant. Leachate from Ru Ri dumpsite is considered the

old leachate, the organic matter was significantly reduced. Leachate from Luong Hoa

Landfill was collected after the period of post-acid (saved on average six months in

phase and an average of 9 months from year 2 onwards), so the design influent

concentration is presented as in Table 1.1.

Leachate of the landfill is from anaerobic condition inside the landfill, leachate is

continued to store into collection pit 500m3 with anaerobic condition as well.

Therefore, the nitrogen of leachate is mainly in the form of ammonium (NH4-N). This

is a initial favorable condition for selecting the trapping gas (stripping) to drive NH3

out of leachate.

First, leachate will be pumped up to the lime and sodium hydroxide mixing tank. The

goal is to increase pH greater than 7. Here, the separation of NH3 will occur by the

equation:

NH4 NH3 + H+ (1)

Adding more lime and soda (OH-) will bias the equation (1) to the right and NH3 will

be gas form in water. With Henry's constant of NH3 in water estimated at 0.75 atm

(mol water/mol air), thus it could be separate NH3 out of water by trapping (stripping).

The amount of lime added in this step helps to increase pH and is the flocculation

matter for the next step.

Leachate which increased pH > 10 from lime and soda mixing tank will be pumped

up to Stripping tower 1 and be distributed evenly over the surface throughout the

branch duct holes. Leachate is distributed evenly from the top to down throughout

the layers of ceramic materials as Raschig rings (specific area of 132 m2/m3), clean

air is pumped from below and contact with water line then drag NH3 out of leachate.

Leachate at the bottom of the tower is continued to pump to soda/caustic tank. Here,

soda is added to keep pH greater than 10. Leachate from soda tank is pumped up to

stripping tower 2 and distributed evenly across the ceramic materials as stripping

tower 1. Clean air is pumped up from bottom to drag most of the residual NH3. Here,

the calculated amount of amonia reduced to less than 40mg/l. The residual amonia

will be involved in processing in the next biological lakes. The rate of clean air / water

from 200 to 250:1 by volume. The height of ceramic material layer is 30cm. Number

of layers is five per tower.

1

Leachate after striping tower 2 will be pumped up to flocculation tank, here an

amount of aluminum alum, HCl, polimer will be added to reduce the pH to neutral

levels. Flocculation process, coagulation and sedimentation also occurs in this tank.

A large amount of suspended solid (SS) and organic matter will be removed through

the sludge at the bottom of the tank. Estimation of COD concentration will be less

than 1000mg/l after this step. The amount of sludge which is separated will be stored

into sludge tank and move up to the landfill periodically.

Leachate after flocculation tank will be led to Aerobic pond 1, here aerobic biological

processes takes place. An aerator will provide enough oxygen for microbial activities.

The need of oxygen for this pond is about 95kg/day. Hydraulic retention time is

estimated from 81 to 90 days. BOD concentration after an aerobic biological tanks

<100 mg / l.

Leachate after Aerobic Lake 1 continues to flow through the Anerobic Pond 2.

Demand of Oxygen for this pondis around 35kg/day. The process also occurs as

lake 1 with the same hydraulic retention time from 81-90 days. BOD concentrations

after aerobic biological lake 2 reaches below 50 mg/l.

Leachate after Aerobic Lake 2 continues to flow through the Plant Pond 3. Here the

biological treatment process also occurs. Hydraulic retention time in lakes from 50 to

54 days. The natural biological processes occur in lake help thoroughly treated

organic matter content and the residual nitrogen after going through the biological

treatment facilities before. After this last plants lake, the effluent concentration will

meet QCVN 25:2009, column B2.

Processing system is automated about 70%, in which using probes pH to add soda

and acid for the physiochemical process, using probe DO to supply oxygen for the

biological lakes and the water level float to operate the pump. Manually operating is

mainly in the case damaged probes, preparation of chemicals in tanks, sample tests,

chemical dose adjustment on PLC control panel, moving the sludge up to landfill,

cleaning the probes, machines maintenance.

III. UNIT WORKS DIMENSION

Main unit works dimension of additional parts of leachate treatment plant is listed in

the table 3.1

Table 3.1 Dimension of additional unit works of the leachate treatment plant

No unit work Dimension Material Note

1. Lime dilution tank (L x W x H) Concrete # 250

Normal

2

3m x 3m x 2.5

2 Intermediate tank 1 3m x 2.5m x 2.5m Concrete # 250

Anti-corrosive

3 Intermediate tank 2 3m x 2.5m x 2.5m Concrete # 250

Anti-corrosive

4 Intermediate tank 3 3m x 2m x 2.5m Concrete # 250

Anti-corrosive

5 Sludge storage tank 5m x 3m x 2.5m Concrete #250

Anti-corrosive

6 Operation and chemical storage house

9m x 4m x4m Concrete, brick, tile, wood

Class IV house

7 Foundation platform (for tripping towers and tanks)

8m x5.5m x 0.2m Concrete # 200

Normal

9 Tripping tower 1 D x H = 2.86m x 9m

CT 3 steel Anti-corrosive

10 Tripping tower 2 D x H = 2.86m x 9m

CT 3 steel Anti-corrosive

11 Coagulation and sedimentation tank

D x H = 3.4m x 5m CT 3 steel Anti-corrosive

IV. INVESTMENT COST ESTIMATION

IV.1 CONSTRUCTION WORKS

Table 4.1 construction work estimated cost

No WORK Unit Amount Unit priceCost

(VND)

1 Lime dilution tank

Tank 126,000,000 26,000,000Dimension: Length x Width x Height

= 3,0m x 3m x 2,5m

Material: concrete #250

2 Intermediate tank 1

Dimension: Length x Width x Height = 3m x 2,5m x 2,5m


Tank 1 22,000,000 22,000,000

Intermediate tank 2 Tank 1 22,000,000 22,000,0003

3

Dimension: Length x Width x Height = 3m x 2,5m x 2,5m


4

Intermediate tank 3

Tank 1 19,500,000

19,500,000

Dimension: Length x Width x Height = 3m x 2m x 2,5m


5

Sludge storage tank

Tank 3 47,000,000

47,000,000

Dimension: Length x Width x Height = 5m x 3 m x 2,5m


6

Operation and chemical storage house

Tank 1 75,000,000

75,000,000

Dimension: Length x Width x Height = 9 m x 4m x 4m

Material: brick and mortar

7

Foundation platform

Piece 1 25,000,000

25,000,000

Dimension: Length x Width x Height = 8m x 5,5m x 0,2 m


Total construction cost236,500,00

0

IV.2 EQUIPMENT AND STEEL UNIT WORK

Table 4.2 equipment and steel work estimated cost

No WORK Unit Amount Unit price Cost

I. MECHANICAL EQUIPMENT 893,500,000

1 Leachate pump (submergible pump)

- Producer: Tsurumi (Japan) or equivalent

set 8 11,500,000 92,000,000

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Flow rate: 8 - 12 m3/h, H = 12,5m

Power: 2 HP

Electricity: 3 phases – 380V – 50Hz

Status: 100% new.

2 Aerator (for pond)

- Producer CMS (Ytaly) or equipvalent

Power: 5,5 KW- 3 phases – 380V – 50Hz

- Capacity: 11,8kg Oxygen/h

- And attached auxiliaries

Set 2 45,000,000 90,000,000

3 Air blower (for tripping tower)

- Producer: ACB (Viet Nam) or equipvalent

Capacity: 3000 m3/h; H = 5m

Power: 5 HP

Set 2 35,000,000 70,000,000

4 Chemical mixing equipment

Bin 4 9,500,000 38,000,000

Mixing motor: OM (Japan) – 0,5HP

Tank material: PVC (Dai Thanh plastic/Viet Nam)

Volume: 1m3

5 Chemical pump

Set 4 8,500,000 34,000,000

Producer: OM Japan) or equivalent

flowrate: 0 – 200 litters/h

Suction head: 10 Pa

electricity: 0,2 kw – 220V – 50Hz

Status: 100% new

6 Chemical bin Bin 3 6,500,000 19,500,000

Material: PVC (Dai Thanh plastic/Viet Nam)

Volume: 4m3

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7 Chemical dosing pump

Set 3 18,500,000 55,500,000

Producer: OM (Japan) or equivalent

Flow rate: 0 – 200 litter/h

Suction head: 10 Pa

Power: 0,5HP – 220V – 50Hz

status: 100% new

8 Compressor

Set 1 9,500,000 9,500,000

Engine producer: Fusheng (Taiwan) or equivalent

Flow rate: 100 – 200litter/minute

Power: 2HP – 380V – 50Hz

9 Tripping tower

Set 2 175,000,000 350,000,000

Dimension: D x H = 2,86m x 9m

Material: CT3 steel, thickness: 4mm,

- 2 sides epoxy painting,

- internal lining of composite (for anti-corrosive),

- external normal paint.

Can be made in Viet Nam

Buffer material: ceramic raschig ring 13m3

10 Coagulation & sedimentation tank

- Dimension: D x H = 3,4m x 5m

- Material: CT3 steel

- Thickness: 5mm,

- 2 sides epoxy painting

- internal lining of composite

-external normal painting

Sludge bar motor: OM (Japan) - 1

set 1 135,000,000 135,000,000

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rotation/minute

Power: 0,25PH – 220V – 50Hz

Can be made in Viet Nam

II. OPERATION SYSTEM, PIPE AND VALVE 120,000,000

1 Operation control and power system

1 85,000,000 85,000,000

- Programmable Logic Controller PLC

- Electricity panel

- Electric items for PLC and panel: LG (Korean)

- Electric wire, jack: LG or Cadivi (Viet Nam)

2 Pipes, Valve, Frame

System

1 35,000,000 35,000,000

Liquid Pipe uPVC – Binh Minh (Viet Nam)

Air pipe: steel & uPVC

Chemical pipe: uPVC

Sum I & II1,013,500,00

0

IV.3 TOTAL INVESTMENT COST ESTIMATION OF IMPROVING LEACHATE TREATMENT

Table 4.3 total investment cost estimation

No Item cost

1 Equipment and steel unit work = 1,013,500,000

2 Construction work = 236,500,000

3 Transportation and labor = 55,000,000

4 Start-up operation, operation training and technology transfer = 40,000,000

Total cost of improving leachate treatment investment = 1,345,000,000

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Note:

- The cost mention above not including VAT (10%).

- The cost mention above includes complete system installation.

V. OTHER RELATED ISSUES

V.1 OPERATION COST (per cubic meter of leachate)

The operation costs estimated are electricity, chemical consumed not including

manpower. The manpower cost should cover the general landfill operation cost.

However, 2 persons are suggested working two shift (a day) look after the leachate

treatment plant.

V.1.1 ELECTRICITY CONSUMED

No equipment power (kW)

amount Number of working hour/day

Electricity consumed

(Kwh/day)

1 Pump (pumping to lime dilution tank)

1.5 1 12 18

2 Pump (pumping to stripping towers)

1.5 2 24 72

3 Pump (pumping to coagulation & sedimentation tank)

1.5 1 24 36

4 Air blower (for stripping tower) 3.75 2 24 180

5 Compressor 1.5 1 4 6

6 Aerator 5.5 2 24 264

10 Mixing motor 0.2 1 24 4.8

Sum 580.8

Electricity cost per day: 580.8 KWh x 1,000 VND/KWh= 580,800 VND

V.1.2. CHEMICAL CONSUMPTION (per day)

- Al2(SO4)3: 0.6kg/m3 x 184m3x 4000 VND/kg = 441,600 VND

- polymer: 5g/m3 x 184m3x 80.000 VND/kg = 73,600 VND

- NaOH: 150g/m3 x 184m3x 10,000 VND/kg = 276,000 VND

- Lime: 1kg/m3 x 184m3x 1,000 VND/kg = 184,000 VND

Sum = 975,200 (VNĐ/VND)

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V.1.3 OPERATION COST PER LEACHATE CUBIC METER

Cd = (580,800 + 975,200) (VND/day)/184(m3/day)= 8,457 VND/m3 of leachate

Monthly cost:

Cm = 30 (day/month) × 1,556,000 (VND/day) = 46,680,000 VND/month

V.2 SOME MAIN ASSURANCE BIND TO CONTRACTOR

The warranty time for construction element is warranted by constructor that signed by

employer. It should be at least a year.

The warranty time for equipment is as the time warranty of producer.

VI. CONSCLUSION

The improving leachate treatment design has utilizes the most recently experiences

on the field of municipal waste management including leachate treatment for tropical

regions. This basic design has considers all technical aspect and also minimize the

cost construction and operation.

Therefore, it would like to ask relevant Department and Organization to consider and

approve the design that in order to implement construction leachate treatment as it’s

would be harmonization in the overall context of the project.

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