Tullamarine landfill - rehabilitation and long-term aftercare

Overview

Tullamarine landfill is located in Western Avenue, Westmeadows and is operated by Transpacific Industries Group Ltd TPI closed the landfill on May 13, 2008. EPA licence HS346 prohibits the disposal of further waste at the landfill. 

TPI is responsible for the rehabilitation and long-term aftercare of the landfill. EPA will replace the licence with a Notice that requires TPI to manage the environmental and community safety issues.   

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Tullamarine Landfill Rehabilitation Advisory Committee (TLRAC)

Following a recent review of community consultation around rehabilitation of the site, EPA appointed OfforSharp and Associates to coordinate a revised community engagement process.  

A refreshed Tullamarine Landfill Rehabilitation Advisory Committee (TLRAC) which includes members from the former advisory committee, new members and an improved process began to meet in June 2009.

TLRAC is a forum where TPI can engage with the community over the landfill rehabilitation issues.

As part of a public nomination process four representatives of the local community and two local environment groups have been selected for the TLRAC . Other members include Transpacific Industries Group (TPI), general environment group, Envirowest, Environment Protection Authority Victoria, Melbourne Water Corporation, Parks Victoria and Melbourne Airports Corporation.

 The diagram below shows the composition of the TLRAC with its new structure:

The new TLRAC will be supported by an independent observer, facilitator, process manager and funds administrator. This team of independent people will make the TLRAC Victoria’s most transparent and fairly run committee, well equipped to deal with the strength and diversity of views about the rehabilitation and future use of the Tullamarine landfill.

The discussions and decisions made by the TLRAC will be available to the public to make the committee fully accountable.

People who want to be kept informed about the committee’s deliberations should contact Barbara Sharp on bsharp@offorsharp.com.au or phone 03 59 89 7676 to be put on a mailing list.

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Landfill rehabilitation and long-term aftercare

Preparing the final surface of a landfill (also called capping)

Landfill capping forms a barrier between material in a landfill and the surface, protecting people and the environment. The primary role of the cap is to minimise the water that can get in to a landfill material which can potentially leach contaminants from the site.

Approximately 40% of the site has already been capped. The remaining 60% of the site is also covered with soil to ensure that landfill contents are not exposed. It is important to have the cap installed across the site as quickly as possible.

Preliminary shaping of the uncapped part of the site has been completed. Over the next two years, TPI will progressively place a low permeability clay layer, a plastic membrane and soil cover over the landfill.

The Tullamarine cap will be amongst the most advanced landfill caps to be built in Australia. TPI has prepared a Construction Quality Assurance Plan for the construction of the cap. This will ensure that the cap meets its approved design. As an area is capped, each component of the cap will be tested before the next part of the cap can be constructed.

EPA has reviewed the Construction Quality Assurance Plan with the assistance of an independent expert. EPA is satisfied that the Construction Quality Assurance Plan will ensure that the constructed cap meets the required cap design.

EPA is confident that the cap design meets best practice standards. The design has passed a rigorous assessment process, including peer reviewed by an international expert. The secondary risk aassessment and environmental audit report in 2007 found the cap would significantly reduce the amount of rainwater seeping into the landfill.

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Groundwater

The Groundwater Quality Management Plan ( PDF) describes the extensive groundwater, leachate and Moonee Ponds Creek monitoring program that will be conducted. The program will be reviewed at the end of 2011 by an environmental auditor and subsequently amended to take into account any recommendations made by the auditor.

Leachate

Contaminated leachate (the liquid created as rubbish decays) in the landfill will require ongoing management into the future. EPA requires that leachate be removed from the site and correctly treated prior to disposal. EPA also requires extensive monitoring of groundwater both within and beyond the landfill and will be using a legal notice to place binding, long-term requirements on TPI to manage this issue. This legal notice will formalise the requirements for ongoing protection of groundwater and the Moonee Ponds Creek.

Light Non Aqueous Phase Liquid (LNAPL)
LNAPL is a liquid found in the landfill that includes various concentrations of hydrocarbons and oils.  LNAPL’s are insoluble and less dense than water and tend to form a layer across the surface of the water table. 

EPA issued a Pollution Abatement Notice on 18 November 2008 to TPI requiring a LNAPL extraction and management plan. The Plan was submitted to EPA on 18 February 2009.

EPA is currently seeking further information from TPI about the off-site disposal options for LNAPL..The plan does not allow any on-site treatment of LNAPL.

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Air Monitoring

Air monitoring is currently being conducted in accordance with TPI’s landfill licence.

Additionally, EPA requires TPI to conduct air monitoring during the current reshaping works, in preparation for construction of the cap. 

View an aerial photograph showing the air monitoring locations and sample periods.

TPI Monitoring Results

Volatile Organic Compounds (VOCs): VOCs are commonly found at low levels in the atmosphere but can be toxic at high levels. The most recent monitoring indicates all volatile organic compounds were below detection levels and therefore pose no risk to human health.

Particles (PM10): Particles of 10 micrometres in size and smaller are measured as they can potentially penetrate into the lungs. All results from the recent sample period were well below the State Environment Protection Policy (Ambient Air Quality) objective of 50  mg/m3 .

Dust: Dust can be a nuisance to the community. The recent sampling period did not show a significant increase in dust from current reshaping works in preparation for capping activities.

TPI's monitoring program is ongoing and requirements will be formalised in a legal notice.

EPA VOC monitoring results:
EPA also conducted VOC monitoring on 14 November 2008 to verify TPI’s results. All volatile organic compounds were below detection levels.

Archives

Recent landfill history

December 2007 – Secondary Risk Assessment and Environmental Audit

On 13 December 2007 an Environmental Audit Report, prepared by an EPA Victoria appointed auditor, which reviews a Secondary Risk Assessment (SRA) of the legacy contamination issues at the Tullamarine site was submitted to EPA. The SRA, prepared by consultants for Transpacific Cleanaway, was submitted to EPA on 13 December 2007.

These reports recommend actions for future monitoring and management of the site, including additional groundwater monitoring, further monitoring of Moonee Ponds Creek and assessment of the feasibility of various clean up measures. Both the assessment and audit recommendations will guide decisions around the ongoing and future management of the landfill up to and beyond its scheduled closure in June 2010.

Further information in relation to these reports is provided below.

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Past environmental management

Past monitoring required by the EPA licence indicated that:

• groundwater bores on the edge of the landfill were impacted by leachate.
• there is an increase in salt levels in Moonee Ponds Creek as it passes the landfill.

As a result, EPA directed Transpacific Cleanaway to undertake a thorough study to assess any risks the landfill poses to groundwater and surface water, particularly Moonee Ponds Creek which passes by the northern boundary of the landfill.

In response, Transpacific Cleanaway conducted a detailed assessment of water quality in Moonee Ponds Creek and installed and sampled further groundwater wells around the site. The results of this initial stage of risk assessment are detailed in the Preliminary Risk Assessment dated May 2004 and Addendum.

• Download the Preliminary Risk Assessment. (PDF, 6102KB or 6.1MB)

• Download the Preliminary Risk Assessment Addendum. (PDF, 126KB)

A review of the Preliminary Risk Assessment was conducted by an independent EPA appointed environmental auditor.

• Download the auditor's review of the Preliminary Risk Assessment. (PDF, 1410KB or 1.4MB)

EPA also required Transpacific Cleanaway to complete a groundwater management plan to address current and potential future impacts from the site. Transpacific Cleanaway is currently completing activities outlined in the most recent EPA endorsed Groundwater Quality Management Plan (GQMP)

Download the Groundwater Quality Management Plan. (PDF)

The Environmental Auditor, in his review of the PRA recommended that further assessment of the potential risks posed by the landfill was required. This has been completed through additional works and was compiled within a Secondary Risk Assessment (SRA).

EPA is aware of the potential environmental impacts of this situation and has directed activities to manage this situation now and beyond the life of the site, for the benefit of the environment and the community.

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Secondary risk assessment

On 13 December 2007 Transpacific Cleanaway submitted the Secondary Risk Assessment (SRA) to EPA. The SRA includes:

• an ecological risk assessment of Moonee Ponds Creek
• delineation of groundwater impacts by modeling and monitoring particularly towards the Maribyrnong River
• further targeted monitoring and risk assessment

The results, conclusions and recommendations of the SRA are summarised in the Executive Summary to the Secondary Risk Assessment.

Download the Executive Summary to the Secondary Risk Assessment (PDF, 1994KB or 1.9MB)

An EPA appointed Environmental Auditor completed a review of the SRA to assess the adequacy of the study, review the results and conclusions of the study, and provide recommendations for the monitoring and ongoing management of any potential risks posed by the landfill. The Auditor’s comments and recommendations are included within the Environmental Audit Report for Tullamarine Landfill (Secondary Risk Assessment).

Unfortunately due to size of the SRA and Audit report files, it is not possible to post the full reports on this website. People interested in receiving a CD-copy of the reports can contact EPA on 03 9695 2722 to request a copy.

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Key findings and recommendations of the Auditor

A review by EPA of the findings and recommendations of the Auditor has identified the following key recommendations to be considered during on-going management:

Groundwater

• Additional bores should be installed to the south, south east and east, including observational wells along Wright St (nearest street to residents).
• Chlorinated hydrocarbon plume identified in buffer land east of the site poses a low risk but requires further delineation and ongoing monitoring.
• Further partitioning assessment of oily leachate (LNAPL) is required to assess the potential partitioning of organic contaminants into leachate/groundwater.

Surface Water

• Further assessment of salinity is required to define the exact areas of high and low salinity in Moonee Ponds Creek adjacent to the landfill, as this is the only discernible impact on the creek.

Groundwater Quality Monitoring and Management

• The existing Groundwater Quality Management Plan (GQMP) should be updated to include on-site and off-site groundwater monitoring as well as the other recommendations of the Auditor.
• The EPA licence should be amended so that the updated GQMP is endorsed by both the Auditor and EPA prior to implementation.
• Transpacific Cleanaway should assess the feasibility and practicability of remediating LNAPL within the landfill.

Surface Water Quality Monitoring and Management

• The updated GQMP should include a surface water, biota and sediment monitoring program.
• The Rock Pond should be included in the surface water monitoring program.
• Monitoring of frog, fish and macro-invertebrate indices should continue.

Risk Management and Remediation

• Transpacific Cleanaway should immediately commence investigating the feasibility of installing an enhanced groundwater recharge system as a form of hydraulic containment to protect Moonee Ponds Creek.
• Triggers be developed for instigating remediation of groundwater off-site.

In response to the Audit of the SRA EPA will provide comment to Transpacific Cleanaway, and seek that the necessary recommendations of the Auditor be addressed in a revision of the existing GQMP.

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