A letter from the US miner raised hope that the jarrah forest inland from Perth would escape its strip mining for bauxite, but Alcoa is keeping its options open.
A letter from the US miner raised hope that the jarrah forest inland from Perth would escape its strip mining for bauxite, but Alcoa is keeping its options open.
In June, residents of the Perth Hills welcomed news that the jarrah forest surrounding them would not be strip-mined for bauxite - but it was a false hope.
A letter from Alcoa (below) to the Liberal member for Kalamunda, Adam Hort, in May appeared on a quick read to offer reassurance that the miner would spare the forest on Perth's south-east fringe, where many people have moved to enjoy nature.
"I have now received written confirmation from Alcoa that ... in plain English, that means no drilling, no exploration and no mining in our part of the Perth Hills," Hort told his constituents in a Facebook post.
However, Alcoa, which plans to mine the jarrah forest for another 40 years, did not write the letter in plain English.
A closer reading, a legal perspective, and enquiries with Alcoa all show the miner has left its options open to extract bauxite from all of its lease, which extends north past Mundaring and covers almost all of the Perth Hills.
Almost all of the Perth Hills are within Alcoa's mining lease (pink boundary). Map: Bibbul Ngarma Aboriginal Association
Mining heads north towards Perth
Alcoa has applications before the WA and Federal Governments to expand its clearing of jarrah forest to the north side of Serpentine Dam - a major water source for Perth that is already threatened by Alcoa's clearing.
The US$12 billion company, which is allowed to drill up to 105,000 exploration holes a year, also wanted to investigate farther north in search of the next forested area to strip mine.
Moving closer to more well-populated areas full of residents who love the forest that surrounds them sparked a furore: in August 2025, five normally conservative local governments, from Pinjarra north to Mundaring, passed resolutions (below) opposing Alcoa.
Four councils voted against any expansion of strip mining.
The Shire of Murray - where Alcoa's Pinjarra refinery is a major employer - opposed it unless the miner accepted 21 pages of detailed conditions it had developed to reduce harm to the environment and water supply.
In November, Alcoa moved to calm concerns by announcing it would remove exploration drilling planned for forests in the Armadale, Kalamunda, Mundaring, Beverley and York local government areas from its plans for state government approval out to 2029.
Alcoa removed northern exploration plans (grey) from its near-term plans but it could restart as early as 2031. Map: Alcoa
Alcoa probably hoped the announcement would placate at least one front in one of WA's biggest-ever environmental battles.
However, many Hills residents were not convinced.
In June, Hort, in a Facebook post, said to his constituents, "many of you rightly raised concerns that this may only be a short-term decision, and that Alcoa could look to bring drilling back in future plans."
Hort told Boiling Cold that he then discussed these concerns with the miner.
"Alcoa confirmed that drilling, exploration and mining in the City of Kalamunda and Shire of Mundaring would not form part of their plans. I asked them to put that position in writing so residents could see for themselves," Hort said.
"If Alcoa ever sought to reverse course or bring drilling, exploration or mining back into the Kalamunda electorate, I would be the first person on the front line fighting against it."
However, Alcoa never changed course; it just delayed exploration drilling a few years.
1 - The fine print
Alcoa is engaged in three environmental approval processes (maps below) to support its dream to stay in WA's jarrah forest until the 2060s:
Some areas in its immediate rolling 5-year mine management plans (MMP) are under review by the WA Environmental Protection Authority (EPA).
An expansion of its northern Huntly mine, which feeds Alcoa's Pinjarra refinery and threatens Perth's water supply, into three new areas is under review by the EPA and the Federal Government.
A strategic assessment designed to ease the path for Federal approvals to 2045 over large unmined areas around both the Huntly and Willowdale mines.
Alcoa's 3 approvals: 1 current mining (yellow), 2 near-term expansion at Huntly (blue), 3 long-term expansion (grey). Maps: Alcoa
Alcoa's letter to Hort was full of reassuring statements for his Kalaumunda constituents:
Its 2023-2027 mining plan under assessment by the EPA had been amended to remove the northern exploration that triggered a backlash in the Perth Hills. "This amendment formalises the removal of proposed low-impact exploration drilling in the northern parts of our mineral lease."
Alcoa also removed these areas from its 2025-2029 plan currently before the WA Government for approval.
"Alcoa has no plans to undertake exploratory drilling in the Kalamunda electorate, including ... during the 2025-2029 MMP or 2026-2030 MMP period."
And longer term, the "Strategic Assessment will cover current operational areas, as well as potential future mine areas, across the Huntly and Willowdale mines through to 2045 and does not include activity in the Shire of Mundaring or Cities of Kalamunda and Armadale."
However, the language of Alcoa's letter does not preclude it from adding areas from the northern portion of its lease back into its 2027-2031 MMP.
Also, the Strategic Assessment includes "potential future mine areas", but not explicitly all potential future mine areas.
So, has Alcoa given up ever mining closer to Perth?
2 - The legal check
Does the boundary of the Federal Strategic Assessment limit the extent of Alcoa's future trip mining?
Ruby Hamilton, a special counsel with the Environmental Defenders' Office, said the Federal Strategic Assessment has a "landscape-scale" scope.
"In practice, Alcoa stands to gain a decades-long approval from the Federal Government without the need to play by everyone else’s rules and front up to the government and the community when it wants to expand or extend its mining operations," Hamilton said.
However, she said there is nothing stopping Alcoa from applying in the future to mine outside the strategic assessment area.
"The existence of the current strategic assessment does not provide any limits on Alcoa’s ability to seek further approvals for mining outside the strategic assessment area," Hamilton said.
3 - Alcoa's chance to clarify
Maybe Alcoa just did not word its letter to Hort carefully enough?
Boiling Cold went back and forth with the miner three times (see below), seeking clarity on its plans for the Perth Hills.
Alcoa's initial response avoided the crucial point - would Alcoa rule out changing its plans?
Alcoa was then asked if it would be fair for the story to lead with "Alcoa refuses to rule out mining in Perth's hills.”
Given the opportunity to rebut this line of reporting, the miner's spokeswoman merely said: "We have nothing further to add."
Alcoa's small concessiion to delay drilling in the Perth Hills by a few years has not dampened opposition.
Francesca Flynn, executive director of Bibbul Ngarma Aboriginal Association (BNAA), a Noongar-led environmental group based in the Perth Hills, said Alcoa's letter to Hort gave the impression that it would never operate in Mundaring, Kalamunda or Armadale.
"But Alcoa has made misleading claims before, so it is difficult to take these assurances at face value," she said.
BNAA chair Walter McGuire said successive WA governments have for decades allowed Alcoa to destroy Noongar land, bypassing the community’s rights to safe drinking water.
"Water is life, and without it, we are nothing," McGuire said.
WA Forests Alliance director Jess Boyce said Alcoa is attempting to appease the public by vaguely alluding to scrapping mining exploration without making any substantial commitment.
"After fierce community opposition in the Perth hills, it is obvious that Alcoa is desperately trying to claw back some social license," she said.
"This is an American-owned company that is acutely aware of the fact that a vast majority of Western Australians would like to see it not just withdraw from Mundaring and Kalamunda, but the whole Darling Range."
Mundaring Shire President Paige McNeil community victories against international mining giants are rare.
"Alcoa’s announcement to remove the northern exploration from their 2025-29 MMP gives our community time to build a continuing case for the permanent protection of our jarrah forest," she said.
"The Shire of Mundaring’s position remains firm, the Mundaring Weir Catchment area must be protected in perpetuity, and we will continue to work to achieve this outcome, however long it takes."
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"Objects to all Alcoa’s bauxite mining activities, particularly exploratory drilling and all mining operations on the Darling Range, including in and the surrounds of the City of Armadale, on the grounds that such activity poses significant environmental and sustainability impacts."
"Opposes any proposed expansion of the ALCOA exploration and mining operations into the Mundaring Weir Catchment and Northern Jarrah Forest because of the severe damage to the environment and loss of habitat for local native species that would result from clearing access for exploration and potential future mining operations."
City of Kalamunda - 12 August 2025 - carried unanimously
"Objects to all Alcoa’s bauxite mining activities, particularly exploratory drilling and all mining operations on the Darling Range, including in and the surrounds of the City of Kalamunda, on the grounds that such activity poses a significant negative impact and risk to the long-term character and amenity of the Perth Hills region."
Shire of Serpentine Jarrahdale - 18 August 2025 - resolved
"Alcoa’s Pinjarra Alumina Refinery Revised Proposal will have significant consequences for the Shire, its environment, residents, visitors and economy.
The proposal provides little, if any, benefit to the residents of Jarrahdale, the broader community of Serpentine Jarrahdale, or the local government - there are no economic, social, environmental or any other real benefits.
The Shire is opposed to the proposal, which will have unacceptable, long-term and likely irreversible impacts on flora, fauna, the local economy and the tourism sector."
"Does not support the two Alcoa Public Environmental Reviews until the following recommendations are addressed" .. followed by 21 pages of detailed recommendations.
Searching for a straight answer
Correspondence between Boilng Cold and Alcoa seeking to confirm if Alcoa had committed to any restraint on its activities beyond the next few years:
Boiling Cold
Is it correct to say Alcoa has committed to NEVER mine any area of its lease except for within the Strategic Assessment Area Boundary or the proposed Myara North and Holyoake mine regions under separate assessment? The material (letter to Hort and details of Strategic Assessment) seems to say that, but I just want to check I haven't missed something.
Alcoa The current strategic assessment area, coupled with the Myara North and Holyoake development envelopes reflect the planned extent of our potential operations across the Huntly and Willowdale mines to 2045. Subject to future approvals, including where relevant, under the WA EP Act, only part of the area within the Strategic Assessment would be mined or disturbed.
Boiling Cold I understand that there is no legal reason why Alcoa cannot, in the future, seek federal approval to mine outside the strategic assessment area. I will confirm that with lawyers who understand the act. If that is correct, it will be fair for me to lead with something along the lines of “Alcoa refuses to rule out mining in Perth's hills.” For full transparency, just telling where your non-response is pushing the story.
Alcoa We have nothing further to add.
Boiling Cold I‘m hoping you can respond to this more focused question: Will Alcoa rule out seeking to operate in the Shire of Mundaring or the Cities of Kalamunda and Armadale in the future?
Alcoa Thanks for the opportunity to clarify, but we have nothing more to add at this time.
I worked in oil & gas in commercial and engineering roles for 20 years. Since 2016, I have written for The West Australian, WAtoday, The Guardian and Boiling Cold, winning five WA Media Awards.
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