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 to manage environmental and community safety issues into the future.

EPA will replace the licence with a notice and will require TPI to manage the environmental and community safety issues for the long term.

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Community engagement

EPA has engaged with the community to ensure they are kept up-to-date about how issues are managed at the site. EPA believes it is important to ensure all voices are equal and effective and appointed OfforSharp and Associates to conduct a review of the Tullamarine landfill community engagement process.  The review included a series of confidential interviews with community members and stakeholders.

OfforSharp released a report in February 2009. The report contained recommendations for an effective community engagement process. The new process will enable direct communication between the community, TPI and EPA Victoria during the rehabilitation of the landfill.   

• For more background information about the OfforSharp review click here. ( PDF, 251KB)
• Download the OfforSharp report ( PDF 623 KB)

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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, helping to protect people and the environment. Minimising the water that can get in to a landfill greatly reduces the potential for leaching of 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 commenced, which prepares the site for capping.

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 and a risk assessment conducted by an independent environmental auditor in 2007.

EPA is satisfied it will assist in making the site safe, for both the community and environment.

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Groundwater

The Groundwater Quality Management Plan ( PDF) specifies the actions that TPI must take to protect the groundwater at the site.

A revised plan that will include post closure requirements is being reviewed by an environmental auditor. It will then be submitted to EPA for approval. 

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)
EPA issued a pollution abatement notice on 18 November 2008 to TPI to require a Light Non Aqueous Phase Liquid (LNAPL is a liquid that include hydrocarbons and oils within the landfill) extraction and management plan. The Plan was submitted on 18 February 2009. EPA is assessing the plan.

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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 SEPP objective of 50  mg/m3 .

Dust: Dust can be a nuisance to the community. The recent sampling period did not show a significant increase due to 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. More EPA VOC monitoring results will be available in January.

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Background

Recent landfill history

TPI convicted of licence breach

On December 15, 2008 Transpacific Cleanaway Pty Ltd was found guilty of breaching its EPA Victoria operating licence for its Tullamarine Landfill operation and was ordered to pay $75,000 to a community environmental project. Click here to read the media release.

Investigation

Following two-days of on-site investigations in late 2007, EPA identified approximately 15,000m3 of suspected contaminated soil and industrial wastes stockpiled on the surface of the landfill. The stockpiling of this suspect material at the landfill rather than its disposal within the landfill is currently subject to an EPA investigation.

On 22 January 2008 EPA issued a minor works Pollution Abatement Notice (PAN) (PDF, 354KB)  that requires Transpacific Cleanaway Ltd to deposit the suspect material into the active tipping area of the landfill.

The suspect material was placed in and filled Stage 6 of the landfill in accordance with the notice.

Whilst health and safety of the environment and community has not been affected, it is necessary that such wastes be managed in accordance with the licence conditions.

Transpacific applied for approval to place the remaining waste in Stage 7.

EPA issued a further minor works Pollution Abatement Notice on 18 February 2008 that specifies that no waste may be accepted at the landfill without the written approval of EPA.

EPA’s investigations into licence compliance at the Tullamarine landfill are continuing.

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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Future environmental management

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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