Welcome to Alcoa’s latest Anglesea Community Update

This year, which while hard to believe marks one decade since closure, has commenced safely as we progress with rehabilitation activities across our former mine and power station site.

After submitting our formal groundwater licence amendment application to the regulator in July 2024, we have recently received confirmation from Southern Rural Water that they have adequate information to inform a licence determination. As a result, formal assessment of the application will commence shortly, including further opportunity for the community to have their say.

In the update below, I am pleased to share a link to our Groundwater Impact Assessment submitted with our licence application, a summary of what we’re seeking, and an offer to learn about our vision firsthand during a site tour.

Warren Sharp | Site Asset Manager

Environment, health and safety

Our work on site continues to be completed safely, with zero injuries recorded this year. Similarly, no environmental non-compliances have been reported to date.

With remediation of the power station site nearing completion, Alcoa is now planning the final phase of the process, oversighted by the EPA-appointed auditor. This involves preparing a final Site Condition Report confirming completion of all remediation works and land suitability for future alternative uses, while also ensuring compliance in accordance with the EPA Environmental Action Notice.

Power station remediation

We have reached a very significant milestone with our power station soil remediation works expected to conclude during May following many years of assessment, planning and site works.

Efforts to date have included:

Comprehensive site wide sampling of soils and local groundwater, including resampling for verification of all works
Targeted environmental remediation that has included the recovery and treatment of historically impacted soils, with the majority of soils safely reused on-site
Reuse and recycling of cleaned crushed concrete, both on and offsite (pictured above)

The process has been overseen by the EPA-appointed auditor, reporting to the EPA, and included numerous EPA site inspections.

Coupled with previous works over the last 10 years, Alcoa can now commence the process of obtaining a Statement of Environmental Audit consistent with the EPA Environmental Action Notice, enabling the power station site to be used for appropriate long-term alternative land uses.

Maintenance and monitoring

Maintenance and monitoring of rehabilitated areas in the mine are key parts of our objective to ensure a safe, stable and sustainable landform.

This program includes extensive weed management, erosion repairs, stability monitoring and regular geotechnical and vegetation expert inspections – activities that are expected to continue over the next five to 10 years.

Geotechnical stability

A bi-monthly geotechnical inspection of the mine as part of our ongoing regulatory requirements was undertaken in April by Alcoa’s geotechnical consultant, with no significant issues identified.

Weed removal works

Our focus on inspecting for and removing noxious and invasive weeds from our site has remained strong and included:

Ongoing woody weed removal including Sallow Wattle and Boneseed, including north of the diversion channel and in proximity to the broader Anglesea Heath
Treating potentially invasive species such as Scotch Thistle, Spiny Rush, Serrated Tussock, Pampas, etc where it is discovered
Continuing trials for treatment of exotic weeds in the mine grasslands including Fescues and Great Brome

Vegetation trial

Under the guidance of our consulting ecologists, three trial areas were prepared in the lower 1 in 3 sections of the mine and spread with sterile (Kikuyu) grass sprigs in October 2024, to determine if vegetating the slopes will assist in mitigating lower slope erosion. Sterile Kikuyu was carefully selected to reduce any risk of adverse impact on rehabilitated areas or the broader heath.

Aided by a temporary sprinkler system (pictured above) and liquid fertiliser application, the grass showed promising signs of establishment across the summer months, resulting in a significant impact on comparable erosion rates.

With the trial now complete and deemed a success, the lessons learned will be incorporated into a formal strategy that will see the grass applied across the remaining 1:3 slopes throughout 2025 and 2026.

It is anticipated that the grass, in combination with the new lateral drains, will significantly reduce erosion on the lower slopes and therefore any ongoing erosion repairs.

Mine water filling strategy

Southern Rural Water (SRW) will soon formally commence assessment of our groundwater licence amendment application submitted to the regulator in July 2024.

The assessment process, facilitated by SRW, will include:

A public advertisement and comment period
An open house style session(s)
A subsequent online submission hearing for those who provided a submission

The purpose of this consultation is to give community and stakeholders an opportunity to provide feedback to Southern Rural Water on our amendment application.

Groundwater licence amendment application summary

The amended application seeks approval from SRW to reduce our existing groundwater licence from 4 gigalitres per year to 1.5 gigalitres per year and amend its use to allow groundwater to be used to fill the mine pit, which is estimated to take seven to ten years. This is less than 38 per cent of Alcoa’s historical groundwater extraction rate.

If approved, the licence will enable Alcoa to accelerate return of the former mine and power station site to the community, consistent with the draft Mine Rehabilitation and Closure Plan, while providing long-term environmental benefits sooner. In contrast, the alternative natural fill approach is expected to take many decades.

To ensure the reduced and amended allocation poses no unacceptable risks to the environment that may rely on the groundwater, a Groundwater Impact Assessment (GIA) has been prepared to support our application and for SRW’s assessment.

The GIA is a technical document that considers multiple sources of data and lines of evidence to determine risk, including:

Review of multiple independent technical assessments
Results of the 2021 purpose-designed groundwater pumping test
Detailed assessment of more than 130 groundwater monitoring points and available surface water flow sources providing a comprehensive and long-term set of data
Analysis of the updated and independently peer reviewed Conceptual Hydrogeological Model showing water relationships in the region
Predictive tools such as the updated and independently peer reviewed 2024 Anglesea Groundwater Model - developed in collaboration with Barwon Water
Hydrogeological risk assessment
Feedback from ongoing and recent community engagement processes and events, including the three open house sessions hosted in May 2024 to seek feedback from the community and stakeholders on a potential groundwater licence amendment application

The GIA is based on long-term water level, water quality, climate and surface water flow observation data that has formed a well-established and understood baseline of conditions across the catchment. Importantly, analysis of this data shows there has been no adverse impact of groundwater extraction in the past on environmental receptors.

Despite the overall low risk and conservative approach, Alcoa recognises that the river system (Alluvial Swamp Aquifer (ASA)) is a sensitive receptor, and that any activity including groundwater extraction does present a risk – albeit low as described in the GIA.

In response, and to monitor for any potential risks, Alcoa are also proposing that one of the key conditions of any amended groundwater licence should be an updated adaptative management and monitoring plan, including trigger levels and actions.

This would help ensure that, in the event any potential (but unexpected) impacts occurred, they would be detected early, and appropriate action could be taken including ceasing the activity. This would reduce the current low risk further.

To read the GIA document in its entirety, visit our website (scroll to the bottom of the linked page).

Southern Rural Water is responsible for regulating groundwater in Southern Victoria under the Water Act 1989. For more information on the groundwater application process, assessment commencement dates and how to make a submission, visit srw.com.au.

If you’re interested in seeing the site and learning firsthand about our proposed plans, requests are welcomed via angleseaps@alcoa.com.au.

Community

We recently hosted individuals from the Bellarine Wanders for a tour of the site. The team received positive feedback from the group, with many of the visitors remarking that our rehabilitation work was substantial and successful!

We acknowledge the importance of our activities to the community and will continue to engage with you as we work toward delivering the best possible outcomes for the future of the site, the community and the environment.

As always, if you have any feedback or questions for Alcoa, please do not hesitate to contact the Anglesea team via angleseaps@alcoa.com.au.

To read more about our activities including previous updates, visit our website.