MELBOURNE REGIONAL LANDFILL Landfill Gas Surface Emissions Monitoring

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1 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 olga.ghiri@transpac.com.au 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 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 Page 1 of 4

2 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 Page 2 of 4

3 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 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. Page 3 of 4

4 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. Retesting N/A by Cleanaway has recorded methane concentrations below action levels. 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 4 Dec 2015 completed. LFG Extraction Well in Stage 2 Flow line to extraction well to be replaced. Further sealing works at 4 Dec 2015 base of well. 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 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 Exposure standards are available for all of the compounds listed above however these exposure standards cannot be compared to NPI emissions data. Page 4 of 4

5 A division of Enviro-Net Australia Pty. Ltd. ABN ACN NATA Reg /2B Parker Street, Footscray, Victoria 3011 Ph: (03) Fax: (03) Web: 18 November 2015 ESP Report Number: J31563-R2.0 Landfill Operations Pty Ltd Christies Road Deer Park VIC 3023 Landfill Gas Surface Emissions Validation Monitoring 1.0 Introduction In November 2015, ESP - Environmental and Safety Professionals performed landfill gas surface validation monitoring at Melbourne Regional Landfill, 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 Guidelines and Standards The works were undertaken in general accordance with the following guidelines and standards: EPA Victoria Publication (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. 1

6 Landfill Gas Surface Emissions Validation Monitoring 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 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. Location Stage 1 Location ID Table 6.1 Stage 1 Validation Monitoring Results Relevant Action Level (ppm) Previous Methane Concentration (ppm) Post-rectification Methane Concentration (ppm) Surface 5C J trap 6C 100 1, J trap 6E Surface 8C Concrete sump 11D White PVC pipe 11F Shading indicates exceedance of relevant action level during validation monitoring 2

7 Landfill Gas Surface Emissions Validation Monitoring Location Stage 2 Location ID Table 6.2 Stage 2 Validation Monitoring Results Relevant Action Level (ppm) Previous Methane Concentration (ppm) Post-rectification Methane Concentration (ppm) Gas well I080 4W 1,000 2, Leachate sump LP07 4X 1,000 1, Leachate sump LP08 5X 1,000 2,830 2,800 Manifold F 8I 1,000 1, 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, Gas well L135 12L 1,000 15, Gas well G051 12M 1,000 4, Gas well J087 17T 1,000 3, Gas well J091 17U 1,000 1, Gas well J096 17V 1,000 5, Gas well X S 1,000 19, Gas well X R 1,000 1, Gas well U O 1,000 28, Gas well U N 1,000 50, White PVC pipe 23Q 1,000 2, Surface 23R Surface 24Q Gas well T V 1,000 29,000 3,000 Gas well S O 1,000 11, Gas well T P 1,000 31, Gas well Q R 1,000 2, Gas well R M 1,000 5, J trap 26N 1,000 14, Gas well R P 1,000 22, Gas well Z343 27AY 1,000 8, Gas well Q203 27Q 1,000 15, Gas well X168 27R 1,000 1, Gas well R P 1,000 1, Surface 29U J trap 31AY 1,000 6,740 5,300 Leachate sump LP22/LP21 31B 1,000 25, Gas well Z340 32AY 1,000 1, Shading indicates exceedance of relevant action level during validation monitoring 3

8 Landfill Gas Surface Emissions Validation Monitoring 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.). Time Temperature ( o C) Table 7.1 Meteorological Conditions (Laverton) 13 November 2015 Relative Humidity (%) Rainfall (mm) since 9am Wind direction Wind speed (km/h) Pressure (hpa) 9:00am SW :00am SW :00am S :00pm SSE 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. 4

9 Landfill Gas Surface Emissions Validation Monitoring 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 5

10 Landfill Gas Surface Emissions Validation Monitoring Figure 1 Previous Results Plan (Stage 1)

11 A B C D E F G H I J K Minor Grid = 25 m Major Grid = 50 m A B C D E F G H I J K TITLE: ADDRESS: JOB NUMBER: Previous Results Plan (Stage 1) J31563 LEGEND: Area Inaccessible Action Level Exceedance (Aug/Sep 2015) DRAWING NUMBER: D1.1 DRAWN BY: TA REFERENCE: Nearmap

12 Landfill Gas Surface Emissions Validation Monitoring Figure 2 Previous Results Plan (Stage 2)

13 A B C D E F G H I J K Minor Grid = 25 m Major Grid = 50 m A B C D E F G H I J K TITLE: ADDRESS: JOB NUMBER: Validation Results Plan (Stage 1) J31563 LEGEND: Area Inaccessible Action Level Exceedance (Nov 2015) Rectification Validated (i.e. below action levels) DRAWING NUMBER: D3.0 DRAWN BY: TA REFERENCE: Nearmap

14 Landfill Gas Surface Emissions Validation Monitoring Figure 3 Validation Results Plan (Stage 1)

15 AW AX AY AZ A AX AY AZ 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 B C D E F G H I J K L M N O P Q R S T U V W X Y TITLE: Previous Results Plan (Stage 2) ADDRESS: JOB NUMBER: J31563 DRAWING NUMBER: D Minor Grid = 25 m Major Grid = 50 m LEGEND: Area Inaccessible Action Level Exceedance (Sep/Aug 2015) DRAWN BY: TA REFERENCE: TPI

16 Landfill Gas Surface Emissions Validation Monitoring Figure 4 Validation Results Plan (Stage 2)

17 AW AX AY AZ A AX AY AZ 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 B C D E F G H I J K L M N O P Q R S T U V W X Y TITLE: Validation Results Plan (Stage 2) ADDRESS: JOB NUMBER: J31563 DRAWING NUMBER: Minor Grid = 25 m Major Grid = 50 m LEGEND: Area Inaccessible Action Level Exceedance Rectification Validated (i.e. below action levels) D4.0 DRAWN BY: TA REFERENCE: TPI

18 Attachment I Equipment Calibration Forms Landfill Gas Surface Emissions Validation Monitoring

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