Alcoa is storing approximately 368 million cubic meters of caustic bauxite residue, known as red mud, across three refineries in Kwinana, Pinjarra, and Wagerup, Western Australia. The amount of waste, which could fill Perth’s Optus Stadium more than 350 times, has not been confirmed as stable according to recent assessments, raising significant concerns about the safety of these storage areas.
This revelation comes from an annual disclosure by the U.S.-based miner, which highlighted that three-quarters of the red mud Alcoa has produced in Western Australia over the past six decades is stored in areas that have “failed to be confirmed or certified as stable” in recent years. The disclosure identified 21 tailings storage areas at Alcoa’s sites that did not meet stability standards, including at least seven flagged in an audit this year and six in 2023.
Alcoa is among 28 global mining companies that have voluntarily committed to meeting the Global International Standard for Tailings Management by August 2025. However, the current findings have sparked concerns about the potential risks associated with these tailings, particularly in the face of extreme weather events.
An Alcoa spokesperson stated that the unconfirmed stability reports are largely due to ongoing work with independent geotechnical experts to assess the tailings facilities and determine necessary upgrades. The spokesperson emphasized that these results do not indicate an increased risk, noting that the facilities are regularly inspected by regulators and independent experts, with no significant issues identified in the most recent inspections.
The Department of Energy, Mines, Industry Regulation and Safety is aware of the situation and is working to address the stability concerns. However, local community leaders and environmental groups have expressed deep concerns. Rusty Geller, president of the Peel Environmental Protection Alliance, questioned how such a hazard was allowed to develop and called for Alcoa to halt further tailings additions until safety can be ensured.
The miner plans to add around 10 million cubic meters to its stockpiles annually. Concerns have been raised that extreme weather, similar to the conditions caused by Cyclone Seroja in 2021, could lead to a breach in the tailings storage walls, potentially resulting in a catastrophic event. Alcoa has conducted dam-break studies using updated weather data to produce emergency response plans, but these plans have not yet been shared with local councils.
Mike Walmsley, president of the Shire of Waroona, expressed concern about the stability of the Wagerup refinery’s tailings facilities. Although the shire has been involved in discussions with Alcoa, it has yet to receive the company’s emergency response plan, which is critical for managing local responses to potential emergencies.
Vince Puccio, a campaigner against pollution from Alcoa’s Wagerup refinery, warned of the catastrophic potential if the tailings storage walls were to breach. Similarly, the Shire of Murray, home to the Pinjarra refinery, has not received Alcoa’s emergency response plan but has expressed strong interest in reviewing it.
Area F at Kwinana is currently rated as the only Alcoa storage area in Western Australia that would cause “very high” consequences if it were to fail.
