Former landfill site at Bicentennial Reserve and Flat Rock Gully

With the assistance of a specialist environmental consultancy firm, Council completed a detailed investigation into the contamination status of the former landfill site’s soil and groundwater. The information was collated into a written report and lodged with the NSW EPA for their assessment.

The results from the investigation indicate that the risk posed to site users is low and that ammonia concentrations slightly above ecological criteria are likely discharging into Flat Rock Creek. An Environmental Management Plan(PDF, 5MB) (EMP) has been developed to assist Council to manage the site in a way that ensures the safety of the public and the environment.

The EPA has now declared Bicentennial Reserve and Flat Rock Gully as contaminated land to be regulated under the Contaminated Land Management Act 1997. The EPA is concerned that leachate from the landfill has impacted the groundwater and that the elevated ammonia in it has the potential to harm water ecology in Flat Rock Creek and an unconfirmed groundwater dependent ecosystem (GDE) downstream. The levels of ammonia are not at a level which would impact human health.

Now that the declaration has been made, the EPA require that the site be managed, and possibly remediated through a Voluntary Management Plan (VMP). Recently, Council submitted a VMP for review. The VMP(PDF, 413KB) outlines Council’s strategy for the ongoing monitoring of ammonia levels in the surface and groundwater. A Sampling, Analytical and Quality Plan(PDF, 2MB) prescribes the methodology for monitoring the ammonia concentrations in surface and ground water. As per the VMP, samples are taken every quarter and will continue until 2027. The EPA have approved all plans.

Results from March 2024(PDF, 3MB) and June 2024(PDF, 2MB) sampling indicate similar results to earlier sampling and were consistent with previous investigations conducted by the Consultants, Consulting Earth Scientists.

What are the next steps?

Until 2027 ongoing sampling of ground water will occur and reported to the EPA. Results will be available on Council’s website.

Contact details:

For more information please contact Council’s Resource Recovery Team Leader at waste@willoughby.nsw.gov.au or 9777 1000.

How and when did Council become aware of possible contamination of groundwater exceeding guideline levels at Bicentennial Reserve?

Council became aware after it commenced its review of the Beaches Link and Gore Hill Freeway Connection Environmental Impact Statement (Beaches Link EIS) in December, 2020 and subsequently initiated an investigation of the site history.

What did Council do next after it became aware of possible contamination of groundwater exceeding guideline levels at Bicentennial Reserve?

Council self-reported by notifying the NSW EPA in writing regarding the possible contamination in early 2021. Upon receiving the notification, the EPA required Council to undertake an investigation of its own into the contamination at Bicentennial Reserve and the risk it poses to the environment. The findings of the investigation were collated in an Environmental Site Investigation (ESI) report and submitted to the EPA to satisfy their request for information.

What does the declaration by the EPA mean?

The former landfill site was already listed on the EPA’s Contaminated land record of notices as being 'Under assessment.' Its current status on the list is 'Regulation being finalised.' This status means that the EPA has completed an assessment of the contamination and decided that the contamination is significant enough to warrant regulation under the Contaminated Land Management Act 1997. A regulatory approach is being finalised. It is likely, even if ammonia levels reduce over time and the contamination is no longer significant enough to warrant regulation, that the site will continue to be listed as 'Contamination formerly regulated under the Contaminated Land Management Act 1997.'

The EPA’s website states 'Land contamination from past site uses is common, mainly in urban environments. If the site is properly remediated or managed, it may not affect the intended future use of the site.' The list only contains contaminated sites that the EPA is aware of. Usually the EPA is made aware through the site owner or polluter notifying the EPA under section 60 of the Contaminated Land Management Act 1997.

The information is published in the NSW Government Gazette and the EPA’s Contaminated land record of notices to inform the public and make potential land purchasers aware of the history of the site. The declaration will not significantly change anything.

What are the next steps?

Council will finalise the Environmental Management Plan (EMP) which details how the former landfill site will be managed. In addition to this, a Voluntary Management Plan (VMP) will be lodged with the EPA, for consideration. The VMP will be developed in response to the declaration. Once the VMP is approved, the EPA will ensure that the plan is carried out according to the proposed timeframe. These two documents together, will ensure the site is managed in an environmentally sound condition and that risks to public health are minimized.

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