When Your Roof Is Your Water Supply

Publicly available information does not yet provide a complete picture of the potential composition, movement and deposition of dust from the proposed Gonneville operation, particularly in relation to surrounding households that rely on roof-collected rainwater.

For those households, the issue is not simply how much dust may leave the mine site. It is what that dust may contain, where it may travel and whether deposition onto household water catchments has been adequately considered.

WHY THIS MATTERS

A rainwater tank begins with the roof.

Material deposited onto roofs and gutters can be washed into household tanks during rainfall. WA Health recognises nearby industrial emissions as a potential source of rainwater contamination and identifies mining and industry as hazards that may require consideration when determining appropriate water testing.

Gonneville is a polymetallic deposit containing nickel, copper, cobalt, palladium and platinum. The presence of these elements in the deposit does not mean they will necessarily occur in off-site dust at harmful concentrations.

It does, however, make the composition and behaviour of project-generated dust an important issue for environmental assessment.

WIND DIRECTION MATTERS

Properties close to the proposed mine may be exposed to dust regardless of which direction they lie from Gonneville, because wind direction and strength vary.

Strong easterly winds experienced in the region are particularly relevant to communities west of the proposed mine, but they are only part of the picture.

For households relying on roof-collected rainwater, airborne material deposited onto roofs and gutters may subsequently be washed into household water tanks.

The unresolved question is not simply how much dust could leave the mine site. It is what that dust could contain, where it could travel and where it could settle.

WHERE IS THE CONTINGENCY PLAN?

Western Australia already recognises that protecting drinking water means planning for contamination events before they happen.

Water Corporation has developed contingency planning for potential contamination events affecting Perth’s public drinking-water supply, including scenarios where alternative water supplies, treatment or water restrictions could be required.

That raises an important question for communities around Gonneville.

What is the equivalent contingency plan for households that rely on rainwater for their drinking water?

If future monitoring detected project-related contaminants in a household rainwater supply, what happens next?

Who provides independent testing? What triggers intervention? Who supplies replacement drinking water? Who pays for cleaning or replacing contaminated tanks, gutters or associated infrastructure? And what happens to properties where rainwater is not an optional supply, but the household’s primary source of drinking water?

These questions should be answered BEFORE operations begin not after an impact is detected.

For rainwater dependent households, our roofs, gutters and tanks effectively form our drinking-water catchment.

Protection should begin at the source.

OUR FINDING

We have not found sufficient publicly available project specific information to determine what Gonneville generated dust could mean for surrounding rainwater-dependent households.

That remains an important unanswered issue.

"STRONG COMMUNITY SUPPORT" What does the evidence actually show

13 March 2026 — “high levels of support for the Project”

May 2026 — “Strong community support”

8 September 2026 — “strong government and community support”

28 September 2026 — “Up until now, we have had really good community support.”

These statements make the underlying evidence important. Chalice has repeatedly relied on community support in its public and investor facing communications, with Local Voices survey results forming part of that narrative.

But what did the surveys actually measure, and when?

WHAT DID LOCAL VOICES ACTUALLY MEASURE?

Chalice has repeatedly referred to its Local Voices surveys when discussing community support for Gonneville.

But a community survey needs to be read in the context of what was asked, who participated, when the survey was conducted and what information respondents had at the time.

Local Voices is designed to measure community attitudes across a range of issues. Participation is voluntary. It is not a referendum on whether Gonneville should proceed, nor is every respondent necessarily a landholder or resident directly affected by the mine, infrastructure corridor or proposed haulage.

A positive response to questions about Chalice, its engagement or its contribution to the community is not necessarily the same thing as support for the complete Gonneville proposal and all of the infrastructure and impacts associated with it.

Likewise, survey results collected before major elements of the proposal became known cannot tell us how respondents would have answered after receiving that information.

So when Chalice describes the results as evidence of “strong community support”, the important question is:

Support for what, from whom, and based on what information?

THE TIMING MATTERS

There is another important limitation when interpreting the 2025 result.

The survey was conducted during March and April 2025.

At that time, the community did not have the level of information about Gonneville and its associated infrastructure that is available today.

The preferred infrastructure corridor had not yet been identified.

Affected landholders had not yet been contacted about that preferred corridor.

Many residents did not yet know whether proposed mining infrastructure could affect their properties or communities.

Since then, substantially more information has entered the public domain about the scale of the project, the proposed water and power infrastructure, the preferred corridor and the potential impacts on private land.

That matters when a 2025 survey result is subsequently used to describe current community sentiment.

Community opinion is not static.

People can only form views based on the information available to them at the time.

A survey undertaken before major elements of a proposal become known cannot, by itself, establish what an informed community thinks about those elements once they are disclosed.

THE REAL TEST: 2026 AND BEYOND.

THE 2026 SURVEY

Chalice conducted another Local Voices survey in 2026, closing on 5 July.

The timing is important.

Chalice states that it began contacting landholders along the preferred infrastructure corridor from May 2026.

This means the survey was conducted during the early stages of direct notification about the preferred corridor.

At that point, many of the implications of the proposed corridor had only recently begun to emerge publicly.

Since then, substantially more information has become available about the proposed infrastructure, affected properties and potential impacts.

The 2026 survey results will therefore provide a useful measure of the views of those who participated at that time.

But they cannot necessarily show how community sentiment may have changed as more information about the proposal has become known.

Chalice states that the results will be independently reviewed by Voconiq and published once processed.

When those results are released, they should be considered alongside the timing of the survey, the number and location of participants, the questions asked and the information available to the community at the time.

INVISIBLE. NOT HARMLESS.

What could be in Gonneville’s dust and where could it go?

Western Australia’s workplace safety regulator is warning employers that airborne contaminants do not have to be visible to pose a health risk.

From 1 December 2026, WA will transition to new Workplace Exposure Limits for airborne contaminants, following a national health-based review.

For communities surrounding the proposed Gonneville mine, that raises an important question:

If understanding what is in airborne dust is essential to protecting workers, what assessment will determine what could leave the Gonneville mine site and reach surrounding residents?

GONNEVILLE WOULD BE A MAJOR SOURCE OF DUST-GENERATING ACTIVITY

The proposed Gonneville Project includes a large open pit mine and associated processing and infrastructure.

Activities including drilling, blasting, crushing, loading, stockpiling, earthworks and vehicle movements can generate airborne particulate matter.

Chalice’s own environmental referral identifies dust as a potential air-quality impact requiring assessment and management.

But simply describing these emissions as “dust” does not tell surrounding communities what they need to know.

What matters is what that dust could contain, the size of the particles, how far they could travel, and where they could eventually be deposited.

NOT ALL DUST IS THE SAME

The potential health significance of airborne dust depends partly on what it contains and the size of the particles.

One contaminant of particular relevance to mining, crushing and earthmoving activities is respirable crystalline silica (RCS). These extremely fine particles can penetrate deep into the lungs and are already subject to a specific workplace exposure limit in Australia.

Gonneville is also a nickel-copper-cobalt-PGE deposit. That does not mean dust leaving the site would contain harmful concentrations of these substances.

It does mean the community needs to know what detailed geochemical and mineralogical testing shows about the ore, waste rock and other materials that could generate dust.

Before potential impacts can be properly understood, we first need to know:

What could actually be in Gonneville’s dust?

DIESEL PARTICULATE MATTER: ANOTHER AIRBORNE CONTAMINANT

From 1 December 2026, a new Australian workplace exposure limit of 0.01 mg/m³ will apply to diesel particulate matter.

Safe Work Australia specifically identifies mining, quarrying, construction, agriculture, transport and logistics among industries where workers may be exposed to diesel engine emissions.

A project of Gonneville’s scale would involve substantial use of heavy vehicles and machinery during construction and mining.

Again, this is a workplace exposure limit, not a community air-quality standard.

But it demonstrates why airborne emissions from a mine need to be understood by more than simply measuring visible dust.

For surrounding communities, the question is:

What does modelling predict about diesel particulate matter and other fine particles beyond the mine boundary?

WHY THIS MATTERS FOR GONNEVILLE

Western Australia’s changing workplace exposure regime reinforces an important principle: airborne contaminants need to be identified, understood and monitored including contaminants that may not be visible.

Workplace exposure limits are not community air-quality standards and cannot, by themselves, tell us what the potential consequences may be for people living around Gonneville.

The EPA has already identified potential air quality impacts from emissions during construction and operation as an issue requiring assessment.

Yet important questions remain for surrounding communities about the composition of mine generated particulate matter, the potential for fine particles and contaminants to travel beyond the mine site, and the consequences of long term industrial activity occurring within a rural residential landscape.

Our separate investigation into dust, drinking water and human health examines these potential pathways in greater detail, including local wind conditions, deposition onto residential roofs and reliance on rainwater tanks.

Environmental studies and modelling may help answer these questions. They do not, on their own, determine whether the resulting impacts are acceptable.

The fundamental questions remain:

WHAT COULD BE IN GONNEVILLE’S DUST?

WHERE COULD IT GO?

AND WHAT COULD THAT MEAN FOR THE COMMUNITIES LIVING AROUND IT?

WHO CARRIES THE RISK?

The investor story of a “de-risked” Gonneville — and what remains unresolved

Chalice’s investor material presents a clear story of progress.

Gonneville is moving towards investment readiness. Infrastructure, financing and offtake are progressing, development options are being preserved and the project is moving towards a Final Investment Decision.

But an investor presentation is not an environmental assessment.

Gonneville’s environmental assessment is still underway and its final impacts, infrastructure footprint and conditions have not yet been determined.

So when Gonneville is described as being “de-risked”, there is another question worth asking:

What happens to the risks that cannot simply be made to disappear?

DE-RISKED FOR WHOM?

Chalice has invested approximately $50 million acquiring around 26 square kilometres of freehold land covering the Gonneville resource and surrounding areas. Chalice itself says these acquisitions have “significantly de-risked” the Project by providing greater certainty over land tenure.

But Gonneville does not stop at the mine boundary.

The proposal being assessed by the EPA includes a 2,034-hectare Infrastructure Development Envelope, within which up to 664 hectares of disturbance is proposed for infrastructure options.

Power, water and access still require physical routes through the surrounding landscape.

Resolving those infrastructure needs may reduce development risk for the project.

It does not remove the environmental, landholder or community impacts associated with the solution.

WHAT DOES GONNEVILLE EVENTUALLY BECOME?

Chalice has described Stage 1 as being scoped for “maximum rate of return and shortest capital payback period” and has repeatedly referred to preserving project “optionality”.

That is understandable from a commercial perspective.

But infrastructure built to preserve future development choices can have physical consequences that last much longer than an investment cycle.

So how much infrastructure is being designed for what Gonneville initially requires — and how much may preserve options for what it could eventually become?

TWO CLOCKS ARE RUNNING

Gonneville’s environmental assessment is progressing alongside engineering, infrastructure planning, financing, offtake negotiations and preparation for Final Investment Decision.

Commercial progress does not mean environmental approval has been predetermined, and regulators can still require changes.

But it creates an important reality.

The Public Environmental Review will occur while a separate stream of commercial, engineering and financing work is also progressing.

That makes rigorous environmental assessment more important, not less.

WHO CARRIES THE RISK?

“De-risking” Gonneville may reduce uncertainty around financing, infrastructure and development.

Chalice’s own 2026 Annual Report shows just how central “de-risking” has become to the corporate strategy.

In its audited Remuneration Report, Chalice includes among its FY2026–27 executive Short-Term Incentive performance conditions an objective to:

“De-risk the Gonneville Project through a defined set of technical, permitting and infrastructure related objectives.”

Those performance conditions also include completing the Gonneville Feasibility Study to support project financing and a Final Investment Decision, increasing project value (NPV), securing financing or a strategic partnering transaction, and delivering shareholder value.

In other words, progressing the technical, permitting and infrastructure pieces of Gonneville is not simply part of the company’s public narrative about “de-risking”. It sits within the performance framework against which executive incentives are assessed.

But the risks outside the investment model do not simply disappear.

The infrastructure still needs land.

The corridor still crosses a landscape.

Environmental impacts still need to be assessed.

And affected communities and landholders still live with whatever is ultimately approved.

So as Gonneville becomes progressively “de-risked” for development, the question remains:

Who carries the risks that are left behind?

THE ENVIRONMENTAL STORY ISN’T FINISHED

The WA Environmental Protection Authority determined that Gonneville requires assessment at the level of Public Environmental Review.

The preliminary environmental factors identified include flora and vegetation, terrestrial fauna, inland waters, landforms, terrestrial environmental quality and social surroundings.

The EPA assessment encompasses the mine and its infrastructure development envelope options.

At Commonwealth level, Gonneville also requires environmental assessment and approval before it can proceed.

Significant questions therefore remain within the statutory assessment process.

What will the final environmental impacts be?

Which impacts can be avoided?

Which can be minimised?

What mitigation may be required?

What conditions might ultimately be imposed?

And what form of proposal will ultimately be considered for approval?

Those questions are not answered simply because a project is becoming more technically or financially advanced.

“De-risked” does not mean “approved”.

And it does not mean “impact-free”.

SHAREHOLDER VALUE

Chalice does not hide the commercial purpose of what it is doing.

It is an ASX-listed company.

Its corporate communications discuss shareholder value, returns, capital efficiency, project economics, financing risk and development options.

That is entirely normal.

Investors provide capital because they expect a return.

The interesting question is therefore not whether Chalice wants Gonneville to create shareholder value.

Of course it does.

The more important question is what happens when the solution that best reduces a project risk does not perfectly align with every other interest affected by the development.

A commercially efficient infrastructure route may not be a landholder’s preferred route.

Infrastructure designed to preserve future development options may have a longer-lived physical presence.

A development timetable attractive to investors can make the timing of regulatory approvals commercially important.

A power solution that reduces project uncertainty still requires infrastructure somewhere in the landscape.

These are precisely the situations in which independent environmental assessment and transparent public scrutiny matter.

Shareholder value is a legitimate interest in Gonneville. It is not the only interest.

THREE VERY DIFFERENT TYPES OF RISK

Perhaps the biggest problem with the word “de-risked” is that it can sound universal.

It isn’t.

Project and investment risk includes financing, construction costs, project economics, offtake, power, water and obtaining the necessary approvals.

Environmental risk includes potential impacts on vegetation, habitat, fauna, waterways, air quality and the wider environment.

Community and landholder risk includes infrastructure location, private property, traffic, rural amenity and uncertainty while routes and project details remain under development.

These are not the same risks.

Reducing one category of risk does not automatically reduce the others.

THE PART THAT DOESN’T FIT ON AN INVESTOR SLIDE

Investor presentations necessarily simplify.

Complex projects are condensed into maps, timelines, milestones, economics and development pathways.

That is their purpose.

But Gonneville exists outside the presentation.

Any infrastructure ultimately approved will exist somewhere physically.

Any approved environmental footprint will exist somewhere physically.

Project traffic will travel on actual roads.

Transmission infrastructure will cross an actual landscape.

Water infrastructure will require an actual route.

And people live within that landscape.

The question isn’t whether Chalice’s investor presentations are wrong because they emphasise progress, opportunity and value.

The question is what becomes less visible when a complicated real-world project is compressed into an investment proposition.

The environmental assessment isn’t finished.

Infrastructure options are still being refined.

Potential impacts remain to be assessed.

And “de-risking” for the project does not tell us, by itself, what happens to every other category of risk.

SO WHO CARRIES IT?

There is no contradiction in saying that Chalice has reduced significant risks to developing Gonneville while environmental, landholder and community risks remain.

Both can be true.

For Chalice and its investors, securing land, progressing engineering, investigating infrastructure, advancing approvals and developing financing options can progressively reduce uncertainty around whether the project can be developed.

But those steps do not necessarily make every underlying risk disappear.

Some risks may be avoided.

Some may be reduced through project design, environmental management or regulatory conditions.

Some may remain.

And some may ultimately be experienced beyond the project itself, by the environment, landholders, surrounding communities, road users or governments responsible for infrastructure and services.

That distinction matters when a project is described as being “de-risked”.

The environmental assessment of Gonneville is not finished. Important elements of the wider development remain unresolved, and the final impacts and conditions are not yet known.

So perhaps the most important question is not whether Gonneville is becoming less risky as an investment.

It is this:

As Gonneville is progressively “de-risked” for development and investment, where do the risks that remain ultimately sit?

BUSHFIRE RISK

What happens when major industrial infrastructure enters an already bushfire prone landscape?

Bushfire risk is not a hypothetical issue in Chittering.

Homes, farms and rural-residential estates already exist within a landscape where bushfire risk influences vegetation management, firebreaks and emergency access.

At Maryville Heights and surrounding areas, fire-management arrangements existed long before Gonneville was proposed.

Now the proposed Gonneville infrastructure corridor would introduce major power and water infrastructure, together with an operational access/maintenance track, into that same landscape.

How has the Gonneville infrastructure corridor been designed around the bushfire-management system that is already here?

ONE CORRIDOR. DIFFERENT FIRE RISKS.

The proposed Gonneville infrastructure corridor crosses very different landscapes.

Through the Maryville Heights rural-residential area, the currently proposed 132 kV transmission infrastructure would be underground. Across other agricultural sections, transmission infrastructure is proposed above ground.

That distinction matters.

At Maryville Heights, the questions include excavation, vegetation clearing, the water pipeline, the operational access/maintenance track, existing strategic firebreaks and nearby homes.

Across farming properties, overhead transmission infrastructure raises a different issue. Western Australia's Planning for Bushfire Guidelines specifically recognise that overhead powerlines are a known ignition source.

Affected Chittering farmers have already raised concerns with the EPA about wildfire response and the proposed overhead transmission infrastructure.

Chalice has also disclosed discussions with Western Power about future-proofing the corridor, but publicly available information does not yet establish what that may mean for the eventual transmission configuration.

Different parts of this corridor present different bushfire management questions.

Where is the assessment showing how each of them will be managed?

WHERE DOES EVERYTHING FIT?

At Maryville Heights, putting the proposed 132 kV power infrastructure underground does not make the corridor disappear.

The power infrastructure still requires excavation. The water pipeline must also be accommodated. An operational access/maintenance track will be required, while existing strategic firebreaks and mature vegetation already occupy this landscape.

Yet we have not located publicly available detailed design information showing how the power, water, operational access and existing fire-management arrangements will physically fit together through Maryville Heights.

Nor have we located information showing the total construction and vegetation-management footprint required to accommodate them.

Affected communities should be able to see that design before the corridor is approved.

THE TREES AREN'T EMPTY SPACE

The proposed corridor also encounters mature native vegetation within the Maryville Heights Tree Preservation Area, including trees containing hollows and potential black-cockatoo habitat.

That creates another practical issue. If construction, the operational access track or bushfire management requires additional vegetation removal or modification, that entire footprint needs to be understood.

This matters because the project surveys we examined did not include physical access to the TPA, while subsequent on ground inspection identified multiple tree hollows.

Fire management, infrastructure and environmental protection all have to fit within the same physical landscape.

WHAT HAPPENS DURING AN ACTUAL FIRE?

The corridor also has to work during an emergency, not just on an engineering drawing.

During a bushfire, residents may be evacuating while firefighting appliances need access. Roads may be restricted, infrastructure may be damaged and existing fire-management routes need to remain usable.

At the same time, the Gonneville infrastructure would require operational access for inspection, maintenance or emergency repair.

How these competing access requirements will operate together is not yet clear from the publicly available corridor information we have reviewed.

That is why bushfire risk, emergency access and infrastructure access need to be considered together before the final corridor is determined.

WHO HAS ASSESSED THE BUSHFIRE RISK?

Bushfire and wildfire response concerns have already been formally raised with the EPA by an affected Chittering landholder.

In its August 2026 response, the EPA confirmed that the proposed water and power infrastructure corridors are a critical component of the Gonneville proposal and form part of its environmental assessment.

However, the response did not identify a corridor specific bushfire assessment, explain whether DFES had assessed the proposed infrastructure, or explain how the wildfire response concerns raised by the landholder would be addressed.

We have also not located a publicly available integrated assessment showing how bushfire risk, emergency access, strategic firebreaks, vegetation management and the proposed Gonneville infrastructure have been considered together.

We have sought clarification directly from DFES. A response is pending, and this investigation will be updated when it is received.

WHAT GIVES WAY?

Chittering's bushfire risk, fire-management arrangements, homes, farms and mature native vegetation were here before Gonneville.

The proposed corridor now has to accommodate major power and water infrastructure, an operational access/maintenance track, existing strategic firebreaks, emergency response requirements and environmental constraints within that same landscape.

If all of those requirements cannot safely coexist within the proposed corridor, something has to change.

The fire-management arrangement?

The access arrangement?

The infrastructure alignment?

The protected vegetation?

Or the corridor itself?

Before the final corridor is approved, affected communities deserve to see the assessment that answers that question.