Feb/April 2023: Serpentine Dam (Western Australia). Perth Drinking Water Supply Threatened by Mining

‘Intergenerational risk’: Alcoa’s troubled mining could double Perth water bills


April 3 2023: Peter Milne

Water bills in WA could double if the high-risk mining practices of Alcoa near a number of Perth’s dams results in contamination, according to the state’s Water Corporation.

Water Corporation described the US aluminium giant’s mining of bauxite in the Darling Scarp as a “very significant intergenerational risk to water quality and security of supply in drinking water catchments” in an internal briefing note obtained by a freedom-of-information request from the Wilderness Society.

The water supply is at risk from heavy rain carrying soil from areas cleared by Alcoa into the dams muddying the normally clear water, making existing water treatment facilities ineffective.

Contamination from spills of oil and the forever chemical PFAS from firefighting foam were also identified as a concern in the September 2022 document summarising work Water Corporation did “in response to increasing risks stemming from bauxite operations”.

More sophisticated water treatment facilities for dams that could be affected by Alcoa’s current and planned mining of the ore used to make aluminium would cost up to $2.6 billion, translating into a doubling of water rates.

Jess Beckerling, director of conservation group WA Forest Alliance, said any increase in water charges would be a slap in the face for West Australians.

“Who would the ordinary West Australian prefer be prioritised, our water supplier, or the Aluminium Company of America?” she said.

Runoff from forests collected in dams is making a falling contribution to south-west water supply as rainfall reduces due to climate change. However, the dams are as vital as ever to the water supply system as they store water from desalination plants and aquifers in winter to be used in summer when demand is highest.

If a critical dam could no longer be used due to contamination, a replacement could cost billions of dollars, which would be additional to the spending on water treatment facilities.

If water treatment facilities or more storage were required, they would take years to build, and meanwhile, not all people would be equally affected.

About 250,000 Water Corporation customers can only be supplied directly from dams due to the system of pipelines in place.

People served by those 250,000 connections would likely have to boil drinking water if the dams were contaminated with soil or switch to bottled water if excessive amounts of hydrocarbons or PFAS were washed into the dams, according to a water industry expert who did not wish to be named as he is not authorised to speak to the media.

The briefing note gives more detail of the threat from Alcoa’s mining to water supply in the south-west of WA, first revealed by this masthead in February.

An Alcoa spokeswoman said the company remained committed to being a sustainable miner and constantly worked to improve its environmental management.

“While potential long-term risks are proposed, it is important to note that Alcoa has been mining in drinking water supply catchment areas for six decades and has never negatively impacted on public drinking water supply,” she said.

Alcoa has its own mining rules

Water Corporation places the blame for the risks it now has to manage on the unique regulatory arrangements Alcoa enjoys.

“Previous mining operations have not been effectively regulated, primarily due to limitations associated with the outdated management framework associated with the relevant State Agreements,” the note said.

Most mining in WA is governed by the independent Environmental Protection Authority and the Department of Water and Environmental Regulation.

However, Alcoa’s mining is governed by a committee of bureaucrats led by the Department of Jobs, Tourism, Science and Innovation and its minister – Deputy Premier Roger Cook – has the final say.

Each year Alcoa submits a rolling five-year mine management plan to the committee – the Mine Management Plan and Liaison Group – and does not have to seek permission to clear native vegetation under the Environmental Protection Act under an exemption granted in 2004.

According to the briefing note, the committee MMPLG has identified increased risks from Alcoa’s mining in recent years that led to “protracted negotiations” before the last two mining plans were approved.

The miner was working closer to dams, in steeper areas more at risk of excessive runoff after a storm, clearing a greater portion of creek valleys feeding the dams, and digging into areas with shallow groundwater.

Plans by Alcoa to go back to areas it previously mined to extract lower grade ore it had left in the past would “create a second wave of disturbance.”

According to the note, Alcoa has cleared more than 220 square kilometres of jarrah forest in the catchment areas of nine Water Corporation dams. More than 50 square kilometres are currently open with no rehabilitation efforts started.

The open area “was a key indicator of risk” for the Water Corporation as this is where water runoff with soil, oil and PFAS is most likely to occur. The area has increased 10-fold in the past 20 years while Alcoa cleared 30 per cent more land than it revegetated.

In the five years to 2022 Alcoa each year on average reported 140 oil spills with a total volume of more than 18,000 litres and 13 spills of PFAS or the less concerning P3 chemical it has used in the past two years.

Failures of drainage works designed to stop water running off the open mine areas were reported an average 42 times a year and “turbidity exceedances” when sediment made water too cloudy were reported an average of 30 times a year.

Since 2020 Alcoa has been restricted to mining areas with less than a nine-degree or (16 per cent) slope no closer than two metres to groundwater, and clear no more than 30 per cent of a creek valley, or sub-catchment, leading to a “reduction in the overall risk profile to the Water Corporation.”

Cook said the Mining Management Plan Liaison Group process allowed relevant experts within the state government to apply the same level of regulatory rigour to Alcoa’s proposed activities that other companies were subject to.

“The state government has made it clear to the company that protecting Perth’s drinking water remains paramount,” he said.

“Alcoa’s current approval to mine is subject to strict criteria that precludes mining in areas of high risk to Perth’s drinking water.”

Cook said a review of the Water Corporation’s monitoring of its dams from mid-2019 to mid-2022 found the water quality was “very good”.

In February, the WA Forest Alliance asked the WA Environmental Protection Authority to review Alcoa’s approved 2022-26 mining plan as well as the 2023-27 plan now under consideration.

The EPA is expected to decide in about a month whether to accept the referral that would subject Alcoa’s mining plans to unprecedented scrutiny and transparency.

In 2020 Alcoa referred a major expansion of its Huntly mine to the EPA and expected to issue an Environmental Review Document for public comment by June 2023.

Alcoa plans riskier mining near Serpentine Dam and massive new exploration


March 7 2023: Peter Milne

Alcoa’s future mining near Serpentine Dam is a greater threat to Perth’s biggest drinking water dam than its present work which is already worrying the West Australian government.

The US firm – that contests its plans pose a greater risk – is also asking for approval to explore more than 60,000 hectares of jarrah forest in a mine plan currently with the state government for review.

Government fears that heavy rain could cause so much sediment run-off from areas already cleared by Alcoa that water from Serpentine Dam would not be drinkable for months or even years were revealed by this masthead in February.

Alcoa’s future mining poses a significant increase in risk to the dam that supplied 18 per cent of Perth’s water in 2020, according to recent internal state government documentation obtained by this masthead.

The proposed clearing and earthworks – detailed in a five-year plan submitted to the Department of Jobs, Tourism, Science and Innovation and a longer-term expansion proposal lodged with the Environmental Protection Authority in 2020 – includes more mining on steep hillsides near the dam where uncontrolled runoff is more likely.

Alcoa intends to clear more than 60 per cent of the forest in some creek valleys, or subcatchments. Its 2023 to 2027 mine plan includes more than 1500 hectares near the dam, more than 70 per cent of which is in “constrained areas” of greatest risk, according to the government documentation.

Contrary to the state government assessment, Alcoa’s interim vice president of Australian operations, Rob Bear, said the company was not proposing to mine in more difficult areas around Serpentine Dam.

“We have extensive experience operating in areas with similar attributes to those being proposed, including proximity to the dam and the nature of the terrain,” he said.

Bear said Alcoa was working with regulators to improve its already stringent practices, including installing hundreds of additional water monitoring bores, and in 2022 reduced the number of drainage failures by 80 per cent.

“We are aligned with government on the need to maintain responsible and safe operations to protect drinking water,” he said.

In its 2023 to 2027 mining and management program, Alcoa also wants access to more than 60,000 hectares of jarrah forest for exploration, according to a person familiar with the plans who is not authorised to talk to the media. Not all of the area explored would be found suitable for mining.

In 2022, Alcoa extracted 31.4 million tonnes of bauxite from the jarrah forest, 75 per cent of the Pittsburgh-based aluminium giant’s global production.

The ore comes from two mining areas: Huntly, which encroaches on Serpentine Dam and supplied alumina refineries in Kwinana and Pinjarra, and Willowdale, which supports the Wagerup refinery. The alumina is shipped to smelters to make aluminium.

Due to delayed mining plan approvals in WA, Alcoa is now mining lower-grade bauxite which has increased production costs, according to Alcoa’s 2022 annual report.

Alcoa’s 2022 to 2026 plan was only approved by State Development Minister Roger Cook in September 2022 and the 2023 to 2027 plan remains under review, a JTSI spokeswoman said.

She said under the approved plan the miner could not work in higher-risk areas without submitting a method to manage those risks that is accepted by the Mining and Management Program Liaison Group, a committee of bureaucrats that approves Alcoa’s mining.

Higher-risk areas include anywhere with a slope greater than 16 degrees and subcatchments where Alcoa plans to clear more than 30 per cent of the vegetation.

Most mining in WA is assessed by the independent Environmental Protection Authority and regulated by the Department of Water and Environmental Regulation.

However, under a 62-year-old legislated agreement with the state, Alcoa’s mining is governed by the liaison group that is led by JTSI – the department tasked with promoting industry, not protecting the environment – and its plans are regarded by the government as commercial in confidence.

In late 2022, Cook gave Alcoa 12 expectations it had to meet to get future mine plans approved.

According to recent internal state government documentation obtained by this masthead, Alcoa then submitted a plan that inadequately addressed these expectations.

WA Forest Alliance convener Jess Beckerling said the level of risk and secrecy surrounding Alcoa’s mining has reached a tipping point and a full and transparent assessment was required.

Last week the alliance referred the 2022-2026 and 2023-2027 plans to the WA EPA, which has 28 days to decide whether it will investigate.

Alcoa’s operations in WA are 40 per cent owned by ASX-listed Melbourne company Alumina Limited.

Alcoa was warned for years about Perth water threats, so why is our biggest dam at risk?


Feb 9 2023: Hamish Hastie & Peter Milne Reporters

(Serpentine Dam surrounded by bauxite mining)

The West Australian government continued to approve Alcoa’s bauxite mining practices, which threaten Perth’s drinking water supply, despite its own departments raising grave concerns about the issue for at least two years.

This masthead can also reveal that the US aluminium giant’s latest mining plans have not met strict expectations set by State Development Minister Roger Cook.

Internal government advice obtained by this masthead exposed serious fears that Alcoa’s mining practices near the Serpentine Dam left the water vulnerable to flows of pollutants and disease-causing pathogens from mining sediment in the event of heavy rainfall.

Alcoa experienced 227 drainage failures and spilled more than 100,000 litres of diesel and hydraulic oil over the past five years including in water catchment zones throughout the Darling Scarp.

A large sediment flow into the Serpentine Dam, which provided 18 per cent of Perth’s drinking water last year, could potentially shut it down for years and result in billions of dollars of taxpayers’ money spent to fix the problem.

The advice shows the Water Corporation, Department of Water and Environmental Regulation (DWER) and Department of Jobs, Tourism, Science and Innovation (JTSI) had frequently raised these concerns with Alcoa over the past two years, but the company’s latest mining plans did not adequately address them.

The fears revolved around the company’s continued push to a non-peer reviewed, self-regulatory pit-level approach to mining in high-slope water catchment areas.

The advisers lamented their concerns had been ignored by Alcoa in its latest mining management program proposal – a rolling five-year plan approved annually by a panel of bureaucrats including JTSI, DWER and Water Corporation, which is signed off by Cook.

The freshest concerns were raised in government feedback to the 2023-27 plan, which advisers said had insufficient information to assess the risks to public drinking water catchments and dams, and was not backed by peer-reviewed science.

The list of expectations

The advisers raised further concerns about Alcoa’s responses to a list of 12 expectations placed on the company’s future mining operations by Cook in his September 2022 approval of last year’s plan.

These expectations included an obligation on Alcoa to submit a 10-year mine plan for assessment by the government panel and that future approvals must have concurrence from Cook, Environment Minister Reece Whitby, and Water Minister Simone McGurk.

Cook also wanted to re-establish a hydrology committee, shut down in 2015, that provided advice to the minister on bauxite mining’s impact on the movement of water in the Perth Hills.

This point was echoed by a spokeswoman from the Water Corporation, who said there was capacity for it to be reconvened.

Despite Cook’s stern expectations, the government’s advice trashed Alcoa’s response, claiming its latest plan was limited, incomplete and not subject to peer review.

Upper house Greens MP Brad Pettit questioned whether political pressure had a part to play in Alcoa’s mining plans being approved at the same time as bureaucrats warned of a major threat to Perth’s drinking water.

Cook, Whitby and McGurk met with Alcoa on December 15 last year, which followed a meeting between Premier Mark McGowan and Alcoa’s global chief executive Roy Harvey in November.

A state government spokesman said McGowan and the senior ministers made it clear in their meetings that risks to Perth’s water sources needed to be appropriately managed.

In addition to Cook’s 12 expectations, the spokesman said Alcoa’s 2022-26 mining plan was approved subject to conditions it did not mine higher-risk areas without submitting a revised risk management plan addressing the government’s concerns.

“To date, Alcoa has not satisfied those concerns and is not currently mining in these areas,” he said.

A JTSI spokesman said the government panel – known as the Mining and Management Program Liaison Group – would not recommend approval of mining in these higher-risk areas until it was satisfied the concerns were addressed.

An Alcoa spokeswoman said the company operated according to its mining and management programs, took its responsibilities seriously and its mining operations had never impacted drinking water supply.

“We continue to work cooperatively with relevant government bodies to address evolving expectations for environmental management,” she said.

Water Corporation tests of Perth dam water quality from 2019 to 2022 found no issues.

How does Alcoa get its approvals?

Alcoa’s approval to mine the Darling Scarp on a lease that spans from Collie to Gidgegannup stems from a State Agreement first inked by the Charles Court’s government in 1961.

It is this legislation and subsequent amendment acts that include the requirement to submit mining management plans annually, their assessment by the government panel, and approval requirements by the state development minister.

This panel is chaired by JTSI and comprised of public servants from Water Corporation; DWER; the departments of Mines, Industry Regulation and Safety; Biodiversity Conservation and Attractions; and Planning, Lands and Heritage.

The panel oversees all of Alcoa’s bauxite mining operations including vegetation clearing permits and mine design, but its decisions are not made public and there is no opportunity for public comment.

Pettitt called for an overhaul of the approvals processes for Alcoa’s bauxite mining.

Experts break down health risk of Alcoa mining threat


Feb 8 2023: Jesinta Burton Reporter

Water quality experts have shed light on the health risks posed by drinking water contaminants amid revelations the government is worried that Alcoa’s bauxite mining practices could shut down Perth’s biggest dam.

On Wednesday, this masthead revealed internal state government documents indicated Alcoa’s operation in the jarrah forest was presenting an increasing threat to the nearby Serpentine Dam, a key part of the city’s drinking water supply network.

Authorities believe the threat has been amplified by a shift in the miner’s practices which has increased the risk of sediment washing into the dam and dragging with it chemical pollutants and disease-causing pathogens.

The government, which has raised concerns with Alcoa, was told by the Water Corporation a spill could necessitate a $2.6 billion spend to clean up the water and force a shutdown of the 78 billion-litre dam which comprises almost one-fifth of Perth’s total water supply.

The dam stores surface runoff, groundwater and desalinated water to meet base load and peak demand in the network, which services more than two million people throughout Perth, the South West, the Goldfields and the agricultural regions.

Though monitoring by the Water Corporation shows water quality to have been “very good”, the state-owned authority said the introduction of pathogens would present a significant risk to public health.

There are strict rules over which human activities can take place in the reservoir protection zone to prevent pathogens entering the water system.

But while disease-causing organisms, viruses and bacteria contaminating a water source are a concern, University of NSW water quality expert Professor Stuart Khan said the threat posed by sediment in the water was two-fold.

Speaking generally, Khan told this masthead sediment runoff had the potential to drag pathogens into the water and impact water treatment processes, making them less effective at removing pathogens and other harmful contaminants.

In the case of bauxite mining, he said that could include everything from dissolved chemicals like aluminium oxide and iron oxide, to heavy metals like cadmium and mercury from crushed rocks.

“A disruption to the treatability of the water can carry very serious public health risks if you don’t have the proper conditions to achieve effective disinfection,” he said.

“The other issue is pH change. If you start to get a highly alkaline or an acidic runoff into that water, or high concentrations of metals like manganese and aluminum, then that makes the water more difficult to treat.”

Unless a water treatment plant was specifically designed to address that problem, Khan said it would not be a quick fix and could take water quality issues directly to the taps of consumers.

The risks of an ever-changing landscape

Alcoa has been clearing to mine bauxite in the jarrah forest for six decades under long-standing state agreements, with its lease spanning a 12,600-square-kilometre area between Perth and Collie.

But the government believes the threat posed by the operation has rapidly increased in recent years, with deeper mine pits, more unrehabilitated areas, and increased removal of the loose rock that sits on top of bedrock across the catchment making it more prone to erosion.

The company has also been moving closer to the water supply, with parts of the operation now within 300 metres of the dam edge.

The likelihood of sediment and dissolved substances travelling into waterways drastically increases during heavy rainfall and extreme weather events in areas susceptible to erosion.

And that is especially problematic in drinking water catchments.

It’s something NSW authorities found out firsthand when a fire swept through a drinking water catchment in western Sydney in 2020, destroying the forest, destabilising the land and sending sediment, ash and debris into Warragamba Dam. This made the water difficult to treat.

The southern half of WA is no stranger to the effects of climate change, which have already resulted in a 20 per cent decline in rainfall and forced the network to rely on other water sources.

University of Western Sydney water quality expert, Professor Ian Wright, said threats to the stability of the landscape were only growing with the increasing frequency of extreme weather events.

“Really, there’s nothing better than forests [for a water catchment]. When you clear the topsoil to get to that bauxite, you increase the risk of erosion and disrupting the salinity,” he said.

“What’s clear is that we’re getting more extreme weather, both drought and heavy rain.

“For a destabilised landscape like a water catchment affected by clearing and mining, this extreme rain, even with rehabilitation techniques that do their best, can make it really hard to hold together the landscape.”

Edith Cowan University researcher Pierre Horwitz echoed those sentiments, and said mining in a water catchment had the potential to change the hydrology and contaminate the water, issues which would persist for many, many years.

A WA government spokesperson said the state had made clear to Alcoa that the drinking water risks needed to be appropriately managed.

An Alcoa spokesperson said the company was improving its water management and monitoring, voluntarily agreeing to stringent reporting of water management-related events.

The company also said it was committed to being a sustainable miner and monitoring its operations, having rehabilitated 6370 of the 7700 hectares it had cleared in WA over the past decade.

Alcoa mining threatens Perth’s drinking water

Feb 8 2023: https://www.watoday.com.au/environment/sustainability/alcoa-mining-threatens-perth-s-drinking-water-20230207-p5cijm.html

Feb 8 2023: Peter Milne Reporter

Drinking water from Perth’s biggest dam could be rendered undrinkable for years thanks to alarming mining practices by Alcoa, potentially causing restrictions and costing the state up to $2.6 billion to clean it up.

The US aluminium giant mines bauxite within 300 metres of the Serpentine Dam, and the risk of sediment flowing into the waterway increased when it changed its methods about five years ago.

Government advisers fear heavy rain could wash so much sediment containing chemical pollutants and disease-causing pathogens into the dam that the water would not be drinkable for months or even years.

Alcoa’s changed mining practices and the risk to Perth’s water supply are detailed in recent internal state government documentation obtained by this masthead.

Serpentine Dam currently holds 78 billion litres of water, enough to supply Perth’s two million people for two months of peak summer consumption. The dam stores surface runoff from the surrounding forest, as well as water from underground aquifers and desalination plants.

The state government’s assessment is that the threat from Alcoa’s mining, just 55 kilometres from the centre of the city, has increased rapidly in recent years.

The company that has mined the northern jarrah forest for 60 years is now working in hillier areas, digging larger pits, and leaving more land unrehabilitated, all of which make sediment runoff more likely, according to the documentation.

The $13 billion company recorded 227 drainage failures across its WA mines in the past five years, and sediment flowed into the dam 46 times in 2021.

In the same period more than 100,000 litres of diesel and hydraulic oil spilled from its truck and earthmoving equipment fleet. In 2022, there were 137 spills with an average volume of 125 litres.

Three state government ministers met with Alcoa in December over concerns about its mining close to the dam.

An Alcoa spokeswoman said it was improving its water management and monitoring and had cut reportable drainage failures to 19 in 2022, only one of which affected a dam. She said all spill areas were cleaned, and it had detected no hydrocarbons downstream from its mining.

“If Alcoa is doing this in one of the most sensitive and public areas, what are they doing further from public view?”

WA Forest Alliance director Jess Beckerling

“Alcoa voluntarily has agreed to stringent reporting of water management-related events that occur in our mining areas,” she said.

“We remain committed to being a sustainable miner and using leading management and monitoring practices in our operations.”

WA Forest Alliance director Jess Beckerling said the risk to Perth’s water supply was unacceptable and immediate action was required.

“If Alcoa is doing this in one of the most sensitive and public areas what are they doing further from public view?” she said.

How Alcoa shapes the land it mines determines whether sediment-laden water reaches the dam or not.

An agreement between Alcoa and Water Corporation requires water from a one in 20-year downpour be retained in sumps for at least five minutes and then drain into bushland, not into streams that feed the dam.

A spokeswoman for Water Minister Simone McGurk said the government had told Alcoa it must appropriately manage risks to dam water quality from its activities.

A review of water monitoring of Perth’s dams for the three years to June 2022 showed all dams, including Serpentine, were very good, the spokeswoman said.

The Alcoa spokeswoman said the company had cleared 7700 hectares in WA in the past decade and rehabilitated 6370 hectares.

The Pittsburgh-based company mines bauxite from a vast 12,600-square-kilometre lease that covers much of the northern jarrah forest from inland of Perth to Collie, 165 kilometres to the south.

In 2022 the UN Intergovernmental Panel on Climate Change concluded with high confidence the biodiverse region was at risk of ecological collapse due to hotter, drier conditions and more fires.

In January, Alcoa chief executive Roy Harvey told Wall Street analysts WA, where the company employs about 4000 people, was critical.

It has three refineries in the state to process the bauxite into aluminium oxide that is shipped to aluminium smelters around the world.

The WA operation is operated by Alcoa and owned by a joint venture, 60 per cent owned by Alcoa and 40 per cent by ASX-listed Alumina Limited, that also has a stake in Victoria’s Portland aluminium smelter as well as overseas operations.

The state-owned Water Corporation estimates facilities to make contaminated water drinkable could take five years to build at a cost up to $2.6 billion for all dams affected by mining.