What is happening?
Dust monitoring and management
Air quality was monitored for six months from November 2024 to April 2025 to assess potential community exposure to dust and other pollutants. An air quality monitoring station was set up in central Pinjarra to check likely worst-case conditions during summer, with higher temperatures and frequent easterly winds.
The monitoring campaign aimed to:
- measure the levels of airborne particles (PM10 and PM2.5) and the metals and silica content of PM10 samples in the central Pinjarra area and compare these levels with air quality guidelines
- measure the levels of deposited dust in the central Pinjarra area and at a background site and compare these levels to evaluate relative amenity impact
- measure gaseous air pollutants (carbon monoxide – CO, nitrogen dioxide – NO2, sulphur dioxide – SO2, ozone – O3) in the central Pinjarra area and compare these levels with air quality guidelines.
Monitoring results were available on the Department’s air quality index (AQI) webpage, with data updated hourly. The report summarising the results was published on 11 November 2025 and can be read at: Pinjarra air quality.
The Department of Health reviewed the results and advised the measured concentrations of dust, metals, respirable crystalline silica and gases are not a public health risk.
Environmental licence amendment and reviews (Part V of the Environmental Protection Act)
The Department amended the Pinjarra Alumina Refinery licence L5271/1983/14 on 9 June 2025 to extend its duration by one year, to 16 June 2026. The licence extension has been granted to allow for the continued lawful operation of the premises while providing time for the Part IV assessment and decision making of the Pinjarra Alumina Refinery Revised Proposal, and the refinery licence review referred to below.
Alcoa lodged a licence amendment application on 6 June 2025, which is under assessment. The Department will advertise the application for public comment on its website and notify registered stakeholders in writing when seeking submissions.
The Department also initiated a review of the Pinjarra refinery licence in 2022 and held public consultation between 9 December 2022 and 30 January 2023. The review is on hold awaiting the outcomes of the Pinjarra Alumina Refinery Revised Proposal assessment under Part IV of the EP Act, further discussed below. Any queries on the review process should be directed to info@dwer.wa.gov.au and quote L5271/1983/14.
Environmental impact assessment and reviews (Part IV of the Environmental Protection Act)
The Environmental Protection Authority (EPA) is currently assessing Alcoa’s proposal to increase production at the Pinjarra refinery and increase the rate of bauxite mining at the existing Huntly Mine. Read more about this proposal and the status of the assessment.
The EPA published two referrals concerning Alcoa’s mining operations for a seven-day public comment period. These third-party referrals related to Alcoa’s approved and proposed mining operations in the Darling Ranges between 2022-26 and 2023-27. This public comment period closed on 15 August 2023. The EPA is now considering submissions and will decide whether to assess the proposals and, if so, the level of assessment. Further advice and information may be sought by the EPA as part of this process.
Background
Dust monitoring and management
Alcoa’s Pinjarra alumina refinery is regulated by the Department of Water and Environmental Regulation under Parts IV and V of the Environmental Protection Act 1986 (EP Act), through Ministerial Statement (MS) 646 and L5271/1983/14. Updates relating to the refinery’s operations, its regulatory instruments, emissions and the Department’s work to investigate recent complaints are detailed below.
The Department and the Shire of Murray have met regarding complaints of dust received by both organisations. The Department will continue to work collaboratively with the Shire, the community and other relevant government agencies to investigate the concerns raised.
Several studies have assessed potential health risks associated with dust from alumina residue storage areas (RSAs), including dust studies in Pinjarra and at other Alcoa RSAs in Western Australia. The information gained from these studies indicates there is no significant public health risk posed by the dust. Nevertheless, the conditions of the Ministerial statement and Part V Licence require controls to manage and minimise dust emissions from the premises.
The report and findings from targeted air quality monitoring over five months in 2023 and 2024 to establish a seasonal baseline are available here: Ambient dust monitoring campaign, Pinjarra.
Across 2021 and 2022, the Department collected dust and soil samples from the Pinjarra area, including samples from properties where residents had reported dust impacts which they attributed to Alcoa operations. The samples were submitted to an independent NATA-accredited laboratory for analysis.
The results were reviewed by the Department of Health, which advised that the dust composition results did not indicate a health risk.
Environmental licensing amendment and reviews (Part V of the EP Act)
Licence L5271/1983/14 issued under Part V of the EP Act regulates emissions and discharges from bauxite (alumina) refining and associated activities and complements the requirements of MS 646.
A copy of the current version of licence L5271/1983/14 and records of decision making on recent amendments to the licence are published on the Department’s website.
The licence requires Alcoa to apply dust control measures and routine maintenance and housekeeping to minimise airborne dust from the bauxite stockpiles and RSA. The licence also requires Alcoa to take specific measures to control the risk of dust generation from oxalate storage.
Alcoa is required to operate three ambient dust monitors at locations to the west, north and south of the RSA. Monitoring data must be reported to the Department annually and Alcoa is also required to report to the Department within two working days if the 24-hour average total for suspended particulates (airborne particles or dust) exceeds 260 µg/m3 at any of the three ambient locations. Alcoa has not reported any exceedances of the 24-hour average at these monitors in the past three calendar year reporting periods.
Alcoa also holds one active approval for work being done at the Pinjarra refinery:
- Works Approval W6813/2023 for works to establish a second residue filtration plant on the western side of the residue storage area, immediately south of the existing residue filtration plant.
The licence for the Pinjarra refinery requires Alcoa to implement a groundwater monitoring program, specifying sampling and analysis methodologies.
Portions of the Pinjarra refinery are also classified under the Contaminated Sites Act 2003 as possibly contaminated – investigation required. The Department is communicating with Alcoa regarding the further investigation necessary to address the classification.
Environmental impact assessment and reviews (Part IV of the EP Act)
In line with the requirements of Ministerial Statement 646, Alcoa prepared and is implementing an Air Quality Management Plan that details the approach to the monitoring and management of emissions to air from the Pinjarra refinery. The plan includes:
- monitoring methods, quality assurance/quality control procedures and sampling frequency for monitoring particulate emissions (including ultrafine particles) and metal emissions from the residue storage area (RSA) and stockpile area
- an assessment of cumulative particulate emissions considering background levels and levels from refinery sources
- sampling locations, methods (including continuous monitoring or campaign monitoring using continuous techniques) and quality assurance/quality control procedures.
Read Ministerial statement 646 (MS 646).
Compliance
Compliance inspections in 2017, 2020 and 2022 did not find any non-compliances with licence conditions.
An increase in complaints led to the Department’s inspection in June 2022 which focused on dust control measures at the refinery. The inspection found adequate dust control measures were being implemented at the refinery and Alcoa was complying with its licence conditions relating to dust control.
Alcoa has a dust management plan in place.
The Department will continue to investigate dust complaints relating to Alcoa’s Pinjarra Refinery. Anyone who is affected by dust in the area should report this to the Department’s Environment Watch Hotline on 1300 784 782 or use the form below or on the environment-watch site.
More information
The Department will update this page as new information comes to hand. Any questions can be sent by email to info@dwer.wa.gov.au.
Submit a report to Environment WAtch
On making a report to Environment WAtch, you will receive a response acknowledging your submission. We may contact you for further information.
Not all matters reported to Environment WAtch are managed by the Department. For reports that relate to a local government or other State or Australian Government agency, we will forward the report to the relevant authority. Please note you may remain anonymous.
Call the Environment WAtch hotline on 1300 784 782 or use the form below to submit a report.
Submit a report to Environment WAtch
Show moreWhen you submit a report to Environment WAtch, you will receive a response from us acknowledging your submission. We may contact you for further information.
Not all matters reported to Environment WAtch are managed by the department. For reports that relate to another local government or other State or Australian Government agency, we will forward the report to the relevant authority. Please note you may remain anonymous.
You can call our Environment WAtch hotline on 1300 784 782 or use the form below to submit your report.
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