MELBOURNE REGIONAL LANDFILL Landfill Gas Surface … · MELBOURNE REGIONAL LANDFILL . Landfill Gas Surface Emissions ... LFG collection system to ensure maximum extraction of

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MELBOURNE REGIONAL LANDFILL Landfill Gas Surface Emissions Monitoring

Cleanaway is pleased to provide the Melbourne Regional Landfill Community Consultation Group (MRLCCG) with a summary and report outlining landfill gas surface emissions validation monitoring for the Melbourne Regional Landfill in Ravenhall.

The monitoring was conducted independentally and an explanatory summary is also provided below, to assist the MRLCCG to understand the technical contents of the report. Any questions or requests for further clarification can be forwarded to Olga Ghiri [email protected]

Summary

Landfill Gas Extraction The monthly total of landfill gas extracted from the Melbourne Regional Landfill is summarised in the graph below as ‘Total LFG’ as measured in standard cubic metres (‘SCM’).

Cleanaway has measured an increasing trend of landfill gas being extracted from the landfill since taking ownership of the landfill at the start of March 2015.

An increasing trend of landfill gas being extracted from the site is a result of greater investment in maintaining and upgrading LFG extraction infrastructure, and the installation of additional LFG extraction infrastructure. These actions will contribute to reducing the potential for odour from the landfill.

A slight decrease in total LFG extracted was recorded in September 2015 and this is due to installation of LFG extraction wells at the landfill as detailed below. After these works were completed an increase in extraction was recorded in October 2015.

mailto:[email protected]

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During August/September 2015 Cleanaway completed installation of replacement LFG extraction wells across the landfill. These improvement works included: 1. Re-drilling of 43 landfill gas extraction wells to replace wells that were found to be not extracting LFG

adequately, and 2. Repairs to landfill gas extraction header lines to allow 12 existing landfill gas extraction wells to operate at

full capacity.

These works will further increase landfill gas extraction from the landfill. Cleanaway will continue to assess the performance of the LFG collection system at the landfill and will manage the LFG collection system to ensure maximum extraction of LFG from the site.

Landfill Gas System Leachate Management Cleanaway completed an investigation in August 2015 to monitor the level of leachate in the LFG extraction wells at the Melbourne Regional Landfill. The investigation focussed on five LFG extraction wells that were not reporting optimal LFG extraction rates, which may have been due to the presence of landfill leachate in the well. Trial pumping of landfill leachate from these wells was completed and the wells typically refilled with leachate within a short time-frame after pumping ceased. As can be seen below, leachate pumping commenced at Well T220 at 8:19 and continued until 10:10 during which time the leachate level was reduced. When the pump was switched off at 10:10 the leachate refilled the well between 10:10 and 10:55 resulting in an increasing leachate level.

The investigation found that leachate extraction pumps need to be installed in all five LFG extraction wells. However, one of the wells contained clay sediment that will need to be removed prior to a pump being installed. Cleanaway has ordered the required pumps and plans to have them installed in December 2015.

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Landfill Gas Surface Emissions Monitoring Landfill Gas Surface Emission Monitoring (SEM) is completed every six months at the landfill by a third-party contractor and involves the use of a sensitive methane detector to measure concentrations of methane at the landfill surface in all accessible areas of the landfill. Cleanaway also conducts spot checks for LFG at the landfill using our own methane detector in-between the scheduled six monthly SEM events. Methane is a major component of LFG and is used as the indicator chemical compound for the presence of LFG. The EPA specifies LFG action levels that are used to compare the SEM data against. These levels are detailed in Table 6.4 of EPA Publication 788.3 Best Practice Environmental Management – Siting, Design, Operation and Rehabilitation of Landfills which is a publicly available document on the EPA website. Stage 1 of the Melbourne Regional Landfill is covered in a final cap and LFG action levels are 100ppm across this portion of the site. Stage 2 of the landfill is covered with an intermediate cover and LFG actions levels are 200ppm at the intermediate cover surface and 1000ppm within 50mm of protrusions through the intermediate cover. Due to settlement of the landfill, impacts from surface activities and erosion of intermediate cover by rain and wind over time, sometimes methane concentrations are found to exceed the LFG action levels. Where this is identified, rectification works are completed as soon as possible and the area is retested to ensure methane concentrations are below LFG action levels. The last SEM event completed in September 2015, showed six exceedances of LFG levels at Stage 1 of the landfill and 34 exceedances of LFG action levels at Stage 2. Rectification works were immediately completed and included additional sealing of protrusions through the landfill cap and placement of additional sealing clay on the surface of the landfill. Following rectification works, two exceedances of the initial six are still being fixed in Stage 1 and five exceedances of the initial 34 are being fixed in Stage 2. All other areas that were tested are below LFG action levels. Cleanaway will continue to manage the LFG extraction system to work towards having no exceedances. A report completed by a third party environmental consultant that contains details of the validation testing is attached to this summary.

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The actions planned to fix remaining exceedances include:

Location Action Completion Date

Leachate Sump in Stage 1

Underground service location to identify electricity supply to leachate sump, excavate around sump and place additional bentonite to seal.

11 Dec 2015

J-Trap in Stage 1 Vacuum to this section of the LFG collection system increased. Re-testing by Cleanaway has recorded methane concentrations below action levels.

N/A

Leachate Sump in Stage 2 Further sealing works required to base of leachate sump. 4 Dec 2015

Manifold Station in Stage 2 Further sealing works required to base of manifold. 4 Dec 2015

Leachate Sump in Stage 2 Further sealing works of the base of the leachate sump to be completed.

4 Dec 2015

LFG Extraction Well in Stage 2 Flow line to extraction well to be replaced. Further sealing works at base of well.

4 Dec 2015

J-Trap in Stage 2 Further sealing works of the J-trap. 4 Dec 2015

Emissions Exposure Standards Potential emissions from the landfill predominately consist of LFG but can include emissions from machinery and processing of the LFG in the on-site power station. LFG consists of a range of chemical compounds. The theoretical level of emissions of these compounds is estimated in the National Pollutant Inventory (‘NPI’) report that Cleanaway prepares each year and submits to the Victorian Environment Protection Authority. Information about the NPI has previously been provided by Cleanaway in the QAs distributed to the community in March 2015. The NPI data reports the theoretical mass of emissions from the Melbourne Regional Landfill in kg/year and therefore it cannot be used as an indication of potential exposure to these compounds, which people on-site or off-site may be exposed to. The NPI results do not indicate the exposure, toxicity or environmental effects of the 52 pollutants assessed. The 52 NPI substances are:

1,1,2-Trichloroethane 1,2-Dichloroethane Acetone

Acetonitrile Acrylonitrile (2-Propenenitrile) Ammonia (total)

Antimony & compounds Arsenic & compounds Benzene Beryllium & compounds Cadmium & compounds Carbon disulfide

Carbon monoxide Chlorine & compounds Chloroethane (ethyl chloride)

Chloroform (trichloromethane) Chlorophenols (di,tri,tetra) Chromium (III) compounds

Chromium (VI) compounds Copper & compounds Cumene (1-methylethylbenzene) Cyclohexane Dichloromethane Ethanol

Ethyl acetate Ethylbenzene Flouride compounds

Formaldehyde (methyl aldehyde) Hydrochloric acid Hydrogen sulfide

Lead & compounds Magnesium oxide fume Mercury & compounds Methyl ethyl ketone Methyl isobutyl ketone Nickel & compounds

Oxides of nitrogen Particulate matter 10.0um Particulate matter 2.5um

Phenol Polychlorinated dioxins and furans (TEQ) Polycyclic aromatic hydrocarbons (B[a]Peq)

Styrene (ethenylbenzene) Sulfur dioxide Tetrachloroethylene

Toluene (Methylbenzene) Total Volatile Organic Compounds Trichloroethylene

Vinyl Chloride Monomer Xylenes (Individual or mixed isomers) Zinc & compounds

n-Hexane

Australian national chemical exposure standards are publicly available at the Safe Work Australia Hazardous Substance Information System at http://hsis.safeworkaustralia.gov.au. Exposure standards are available for all of the compounds listed above however these exposure standards cannot be compared to NPI emissions data.

http://hsis.safeworkaustralia.gov.au/

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A division of Enviro-Net Australia Pty. Ltd. ABN 39 067 499 389 ACN 067 499 389 NATA Reg. 3110

2/2B Parker Street, Footscray, Victoria 3011 Ph: (03) 9688 8000 Fax: (03) 9689 6470

Web: www.environet.com.au

18 November 2015 ESP Report Number: J31563-R2.0

Landfill Operations Pty Ltd

1100-1152 Christies Road

Deer Park VIC 3023

Landfill Gas Surface Emissions Validation Monitoring Melbourne Regional Landfill, Deer Park

1.0 Introduction

In November 2015, ESP - Environmental and Safety Professionals performed landfill gas surface

validation monitoring at Melbourne Regional Landfill, 1100-1152 Christies Road, Deer Park (site).

2.0 Objectives

The objective of the assessment was to verify whether surface rectification works undertaken at site

had reduced fugitive landfill gas emissions from the surface cap of landfill Stages 1 and 2 since

previous monitoring in August and September 2015.

3.0 Guidelines and Standards

The works were undertaken in general accordance with the following guidelines and standards:

EPA Victoria Publication 788.2 (2014), Best Practice Environmental Management – Siting,

Design, Operation and Rehabilitation of Landfills (Landfill BPEM); and

EPA Victoria Publication 1416 (2011), Draft Landfill Gas Fugitive Emissions Monitoring

Guidelines; and

Other national or international guidelines where applicable.

4.0 Scope of Works

The scope of works for landfill gas emission monitoring included the following:

Project setup and site review: a review of site information to investigate previous

assessment works and current landfill cell configurations. Information reviewed included site

plans, former environmental reports and discussions with site occupants.

Landfill gas surface validation monitoring: monitoring of surface landfill gas emissions at

forty (40) locations where rectification works had been undertaken at the Stage 1 Landfill

cap and the Stage 2 Landfill cap.

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Data reporting: a letter report collating the validation monitoring results, summarising

observations, conditions and conclusions.

5.0 Methodology & Performance Criteria

Monitoring of gas emissions at the landfill cap surface was undertaken by a walkover survey around

forty (40) locations previously identified to exceed the Landfill BPEM action levels during monitoring

in August and September 2015 (refer Figures 1 & 2 – Previous Results Plans).

In accordance with EPA Victoria Publication 1416 (2011), methane measurements were taken

approximately 50 mm from the surface and/or from penetrations of the surface cap using a Gazomat

Inspectra Laser Gas device, capable of 1.0 ppm methane sensitivity, which was calibrated to

standard gases prior to use (refer calibration certificates presented in Appendix I).

The Landfill BPEM provides methane concentration action levels for different monitoring locations

dependant on the surface type and the presence of surface penetrations. ESP was advised by the

client that the Stage 1 surface was the final cap, whereas the Stage 2 landfill surface represented

intermediate cover. A summary of the adopted methane action levels is provided in Table 5.1.

Table 5.1 – Adopted Methane Action Levels

Location Type Parameter BPEM Action Level Applicable To

Landfill Surface (final cap) Methane 100 ppm Stage 1

Within 50 mm of penetration through the

final cap Methane 100 ppm Stage 1

Landfill Surface (intermediate cover) Methane 200 ppm Stage 2

Within 50 mm of penetration through the

intermediate cover Methane 1,000 ppm Stage 2

6.0 Results

Results of validation methane monitoring (following rectification works) are summarised in Tables

6.1 and 6.2 below, with a comparison to previous results (August and September 2015) and relevant

action levels.

Table 6.1 – Stage 1 Validation Monitoring Results

Location Location

ID Relevant Action

Level (ppm) Previous Methane

Concentration (ppm) Post-rectification Methane

Concentration (ppm)

Stage 1

Surface 5C 100 264 2.1

J trap 6C 100 1,509 701

J trap 6E 100 590 1.1

Surface 8C 100 225 25.6

Concrete sump 11D 100 669 520

White PVC pipe 11F 100 701 20.7

Shading indicates exceedance of relevant action level during validation monitoring


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Table 6.2 – Stage 2 Validation Monitoring Results

Location Location

ID Relevant Action

Level (ppm) Previous Methane

Concentration (ppm) Post-rectification Methane

Concentration (ppm)

Stage 2

Gas well I080 4W 1,000 2,089 13.1

Leachate sump LP07 4X 1,000 1,128 706

Leachate sump LP08 5X 1,000 2,830 2,800

Manifold F 8I 1,000 1,079 38

Manifold G 8K 1,000 1,709 4,700

Surface north of LP09

8X# 1,000 3,489 1,300

Gas well G050 11K 1,000 31,000 17.8

Gas well L135 12L 1,000 15,000 788

Gas well G051 12M 1,000 4,494 50.2

Gas well J087 17T 1,000 3,285 2.4

Gas well J091 17U 1,000 1,023 2.8

Gas well J096 17V 1,000 5,081 2.7

Gas well X0254 19S 1,000 19,000 1.6

Gas well X0247 20R 1,000 1,347 1.9

Gas well U0233 22O 1,000 28,000 2.5

Gas well U0227 23N 1,000 50,000 2.1

White PVC pipe 23Q 1,000 2,249 2.0

Surface 23R 200 310 2.1

Surface 24Q 200 250 1.7

Gas well T0230 24V 1,000 29,000 3,000

Gas well S0212 25O 1,000 11,000 3.4

Gas well T0218 25P 1,000 31,000 1.6

Gas well Q0339 25R 1,000 2,133 1.6

Gas well R0207 26M 1,000 5,431 2.7

J trap 26N 1,000 14,000 2.0

Gas well R0208 26P 1,000 22,000 4.3

Gas well Z343 27AY 1,000 8,064 44.0

Gas well Q203 27Q 1,000 15,000 1.8

Gas well X168 27R 1,000 1,062 2.6

Gas well R0198 28P 1,000 1,234 3.9

Surface 29U 200 733 3.2

J trap 31AY 1,000 6,740 5,300

Leachate sump LP22/LP21

31B 1,000 25,000 370

Gas well Z340 32AY 1,000 1,899 82

Shading indicates exceedance of relevant action level during validation monitoring


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The results of validation monitoring indicated that out of a total of forty (40) locations previously

reported to exceed the relevant action levels in August and September 2015, seven (7) locations

continued to report elevated methane concentrations in November 2015 following rectification

works (refer Figures 3 & 4 – Validation Results Plans).

7.0 Quality Control

To satisfy the overall objectives of the assessment, ESP implemented a quality assurance program

during the assessment which included selection of appropriate instrumentation, confirmation of

instrument calibration, review of instrument operating manuals and relevant guidelines, and

completion of monitoring under appropriate meteorological conditions.

A summary of meteorological conditions as recorded by the Bureau of Meteorology (Laverton

weather station) during landfill gas monitoring works on 13 November 2015 is presented in Table 7.1

below.

It is noted that although the Laverton weather station is the closest to site, local conditions at site

may vary due to several factors (e.g. distance inland, topography of landfill stages etc.).

Table 7.1 – Meteorological Conditions (Laverton) – 13 November 2015

Time Temperature (oC) Relative

Humidity (%) Rainfall (mm)

since 9am Wind

direction Wind speed

(km/h) Pressure

(hPa)

9:00am 14.0 82 0.6 SW 17 1017.6

10:00am 15.0 79 0.0 SW 17 1017.4

11:00am 17.1 63 0.0 S 24 1017.6

12:00pm 17.8 57 0.0 SSE 24 1017.7

No heavy rainfall, frost or sharply rising atmospheric pressure was observed during monitoring or

within the 48 hours prior to monitoring. Near-surface wind conditions at site were noted by field

personnel to vary from mostly still to a breeze throughout the time of assessment. It is considered

that monitoring was completed under satisfactory meteorological conditions for the purposes of the

validation assessment, in general accordance with EPA guidelines.

8.0 Conclusions & Recommendations

Conclusions

The results of landfill gas validation monitoring indicated that there was a reduction in exceedances

of the relevant BPEM methane concentration action levels from forty (August/September 2015)

down to seven (November 2015) following rectification works within Stage 1 and Stage 2. The

majority of elevated methane concentrations were associated with surface penetrations (e.g. gas

wells and leachate pumps).

It is understood from the client that resumption of extraction and/or increase in vacuum is expected

to reduce landfill gas emissions from four of the seven locations reporting exceedances.


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One further location is scheduled to be re-sealed with bentonite, and a flow line to another location

is scheduled for remedial works by the end of the year (requires internal road closure).

Recommendations

Based on the monitoring results, it is recommended that further rectification works at those

locations reporting exceedances of BPEM action levels be undertaken, followed by further landfill

gas validation monitoring to assess the effectiveness of the additional rectification works.

9.0 Limitations

This report has been prepared for the sole use of Landfill Operations Pty Ltd (the requesting client)

and shall not be relied upon by any third party without authorisation from ESP.

The application of this report should be consistent with the stated objectives as outlined in the

introduction of this report. The report should be read in its entirety and shall not be reproduced

except in full. The information set out in this report was considered accurate at the time of

completion of site works and is specific to those areas which formed part of the assessment.

Conditions encountered during assessment may or may not be indicative of conditions across the

remainder of the site and conditions can change over time either naturally or by anthropogenic

means. These factors should be considered in future application of this report.

Attachments

Figure 1 Previous Results Plan (Stage 1)

Figure 2 Previous Results Plan (Stage 2)

Figure 3 Validation Results Plan (Stage 1)

Figure 4 Validation Results Plan (Stage 2)

Appendix I Equipment Calibration Forms


Figure 1

Previous Results Plan (Stage 1)

A B C D E F G H I J K


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Major Grid = 50 m


Melbourne Regional Landfill, Deer Park

J31563

TITLE:

ADDRESS:

JOB NUMBER:

DRAWING NUMBER: DRAWN BY: REFERENCE:D1.1

LEGEND:

TA Nearmap

Area Inaccessible

Action Level Exceedance (Aug/Sep 2015)

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Figure 2




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Major Grid = 50 m

Validation Results Plan (Stage 1)


J31563

TITLE:

ADDRESS:

JOB NUMBER:


LEGEND:

TA Nearmap

Area Inaccessible

Action Level Exceedance (Nov 2015)

Rectification Validated (i.e. below action levels)

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Figure 3


A B C D E F G H I J K L M N O P Q R S T U V W X Y


AX AY AZ

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Minor Grid = 25 mMajor Grid = 50 m



J31563

TITLE:

ADDRESS:

JOB NUMBER:


LEGEND:

TA TPI

Area Inaccessible

Action Level Exceedance (Sep/Aug 2015)

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Figure 4




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J31563

TITLE:

ADDRESS:

JOB NUMBER:


LEGEND:

TA TPI

Area Inaccessible

Action Level Exceedance

Rectification Validated (i.e. below action levels)

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Attachment I

Equipment Calibration Forms

Documents

MELBOURNE REGIONAL LANDFILL Landfill Gas Surface … · MELBOURNE REGIONAL LANDFILL . Landfill Gas Surface Emissions ... LFG collection system to ensure maximum extraction of