Concerns over potential mercury pollution from Alcoa’s Wagerup Alumina Refinery has led the Conservation Council of WA (CCWA) to lodge an appeal against the approval of a licence by the Department of Water and Environmental Regulation (DWER).
The DWER licence (6217/1983/15) review has shown a spike in mercury emissions from the refinery since 2023. The review shows that in 2025, 400kg of mercury was released, nearly double the 2022 level.
CCWA Executive Director Matt Roberts said the spike was not reported to DWER by Alcoa through compliance reporting but was instead picked up through the National Pollutant Inventory in 2023.
“It seems Alcoa has seen increased mercury emissions from the Wagerup refinery for at least three years, with no action taken to remedy that. This raises serious questions about our state regulator’s capacity to effectively hold the US-based miner to account,” Mr Roberts said.
“In its response, Alcoa explained the increase as being due to higher levels of mercury in the ore and a faulty condenser.
“Neither of these reasons are credible excuses for the ongoing release of mercury into the environment, and it raises serious concerns about the capacity of the regulator to meet its obligations to protect the environment from harm.
“More than eight threatened species live within 2km of the Wagerup refinery.
“The licence application provided no research on the mercury levels in the environment or in threatened species like the numbat, chuditch, western ringtail possum, the rainbow bee-eater, black cockatoos, and Carter’s freshwater mussel.
“There are safety thresholds for mercury, but if Alcoa isn’t doing comprehensive environmental monitoring, we have no way of knowing whether there is a problem.
“Mercury is a dangerous neurotoxin which bioaccumulates in the environment. Alcoa is not required to undertake the most comprehensive of environmental testing, so we don’t know the full extent of the accumulation and if environmental thresholds are being exceeded.”
The Decision Report states:
12.2 Mercury *(pg 28) “The delegated officer considered the apparent increase in mercury emissions from the premises reported in the Minister’s Appeal Determination (143 of 2015) and the implications for public health criteria.
The delegated officer is satisfied that the apparent increase is likely the result of variation in mercury content in the bauxite; however, acknowledges that increased mercury to air emissions from 2022 to 2025 are also likely to have been influenced due to decreased performance of the condensers.
Critically (as discussed in section 8) the HRA along with the licence holder’s sensitivity analysis demonstrates that an increase in mercury emissions can be tolerated without posing an unacceptable risk to receptors (Katestone 2020; Alcoa 2023a)."
ENDS
Media contact: John Cooke – 0433 679 780