Cadia gold mine

The NSW EPA is continually working to ensure that Newmont’s Cadia Holdings Pty Ltd mine in Central West NSW is operating in compliance with its environmental obligations, in a way that minimises impacts from their operations, and to safeguard the community and the environment.

Regulation

Cadia Valley Operations are required to comply with site specific conditions and controls aimed at minimising the impacts from their operations on the environment and community.

The EPA has completed our latest review of the Cadia mine licence having received valuable feedback from a range of stakeholders. Consultation on the review of the licence ran for six weeks, from 11 March 2024 to 22 April 2024. The Consultation summary report is available, providing an overview of the key feedback heard during the public consultation.

In response we will soon implement variations to strengthen air and water monitoring requirements and improve community engagement. Identified components for variation include a complete review of Cadia’s surface and groundwater monitoring network, air quality monitoring and emission limits, and updates to premises descriptions and outdated conditions across the licence.

These conditions will be outlined in an environment protection licence issued by the EPA to Cadia Holdings and will be legally enforceable. The licence will then be made available on the EPA's public register.

We have also been investigating a range of community concerns related to air, water and soil quality, and have released reports on Lead isotope testing (including of soils and rainwater tank sediments), Air quality monitoring (air sampling) and Water sampling (surface water and groundwater). You can find these below.

The EPA has launched various prosecutions in the NSW Land and Environment Court against Cadia Holdings.

  • The EPA commenced three charges against Cadia alleging that in November 2021, March 2022 and May 2023, the mine exceeded the standard of concentration for solid particles (total) as a result of operating surface exhaust fans attached to Ventilation Rise 8. Cadia plead guilty to all three charges and a sentence hearing was held on 21 June 2024. We are currently awaiting judgment. 

  • The EPA also commenced two charges against Cadia relating to alleged air pollution from the surface of Cadia’s tailing storage facility in October 2022. Cadia Holdings have entered a plea of not guilty in relation to both charges and the matter is listed for further directions on 21 February 2025.

The EPA will continue to monitor Cadia’s mining operations and licence compliance and will take necessary regulatory action, including prosecutions, where appropriate.

Planning modification

Cadia mine has submitted a proposed modification application. The EPA has reviewed the application and has provided comment to the scoping letter to the Department of Housing, Planning and Infrastructure. For more information, go to the NSW Planning Portal.

The EPA’s monitoring programs

Testing for lead isotopes in rainwater tank sediments

Many residents in the area surrounding Cadia mine rely on rainwater tanks for their domestic water supply. In response to community concerns, the EPA conducted an independent study examining rainwater tank and soil samples in the Cadia local area. We tested samples from tank sediments, soils and potential emission sources from the mine to measure lead isotopic compositions and identify the lead's origin. We also compared samples collected to known sources of lead, including the Broken Hill orebody. Historically, the Broken Hill orebody was commonly used in Australian products like leaded petrol and paint.

Findings

The study found that lead in soil and tank sediments mainly matched natural background levels and lead from the Broken Hill orebody. Two tank sediment samples, taken 16-20 km northeast of the mine showed other potential lead sources. These two samples were near the Great Western Highway, the trainline running between Orange and Blayney, and Orange airport.

Read the full Lead isotope testing report (PDF 4.7MB).

Information on rainwater tank management and cleaning can be found on the NSW Health website.

Water from rainwater tanks and kitchen taps

We have collected samples from 97 residential properties to check the concentration of metals in water. Our specialist officers worked to a sampling plan to make sure samples were collected at each property using consistent methodology. Water samples were collected from kitchen taps at residences by letting the tap run to release one litre of water, before we collected the sample in a container supplied by our National Association of Testing Authorities accredited laboratory. We sampled water from residents’ rainwater tanks, bores, dams, creeks and downpipes. We also took sediment samples from rainwater tanks where possible. 

All samples were analysed for metals. Residents’ kitchen tap water was also analysed for total dissolved solids, total hardness, colour, turbidity, pH, nitrate, nitrite, sodium, fluoride and iodine. 

Findings

We have received the results for samples collected from the 97 properties sampled. We have compared the results of the water testing to the national guidelines for drinking water, known as the Australian Drinking Water Guidelines (ADWG).

The majority of results from kitchen tap samples showed metals concentrations below the health-based guideline values.

At three properties, the levels of lead in samples collected from the kitchen tap were at or marginally above the health-based guideline value for lead on the day of sampling. The level of lead in the tank water samples from these three properties did not exceed the health-based guideline value.

At one property, the level of nickel in the sample collected from the kitchen tap marginally exceeded the health-based guideline value for nickel. Nickel was not detected in the water tank sample from this property.

Some water tank samples had levels of lead (14 properties) or cadmium (two properties) or antimony (one property) above the health-based guideline values. Samples taken at the corresponding kitchen tap on these properties did not detect the same metals above the health-based guideline value.

Other metals in tank water samples were below the respective health-based guideline values on the day of sampling.

Some samples also recorded pH in kitchen tap and tank water tap samples outside the range described in the ADWG, on the day of sampling. This range is based on minimising corrosion and encrustation of plumbing fittings and pipes rather than a risk to human health.

There were some mixed results for aesthetic values (including zinc, colour, copper, total dissolved solids, turbidity, hardness, iron and aluminium) in kitchen tap and tank water samples outside the range described in the ADWG, on the day of sampling. An aesthetic guideline value is the concentration below which the water quality is considered acceptable to the consumer, for example, appearance, taste and odour.

These results indicate the importance of maintaining tanks and tank water distribution systems in accordance with guidance provide by NSW Health. Property owners might also consider installing filtration and/or first flush systems to reduce potential contamination of their drinking water.

Sediment in rainwater tanks

We understand testing sediment from rainwater tanks is important for the community. We took samples of sediment from rainwater tanks where it was safe to do so. To get safe access, sediment samples were collected from first flush system or with a sampling device direct from the bottom of the rainwater tank. We took samples from 52 properties; 41 samples had sufficient volume for metal analysis. 

The EPA analysed 41 sediment samples. The results have been compared to results of other studies of sediment in Australian water tanks. All key metals measured were within typical concentrations found in Australian tanks, with the exception of nickel which was exceeded in two samples. For these two samples nickel did not exceed the health-based guideline value at the kitchen tap. 

There are no relevant guideline values comparable to the sediment samples. The ADWG provide a basis for determining the quality of water to be supplied to consumers in all parts of Australia to ensure safety at the point of use. The Australian and New Zealand sediment quality guidelines are targeted to the protection of aquatic ecosystems and livestock (ANZG 2018). In the absence of suitable guideline values, we compared the concentrations of metals in tank sediments collected around Cadia Valley Operations to those measured in other parts of Australia.

Next steps

Isotope testing of a subset of sediment samples, surface and subsurface soils in the Cadia local area, and vent emissions and tailings from the mine has been undertaken. The lead isotope ratios in the soil and sediment samples were compared to those in the vent emissions and tailings, to help identify the potential source of lead in sediment and soils.

You can find a copy of the report here. The EPA’s Expert Panel has reviewed the report and advised the conclusions were supported by the data.

No further rainwater tank testing is proposed.

Testing air quality for pollutants

From August 2023 to May 2024, the EPA and the Department of Climate Change, Energy, the Environment and Water (DCCEEW) conducted an extensive air quality study in the area surrounding the Cadia mine. The study included 36 air monitors, a temporary air station in Millthorpe and six air samplers measuring dust and metals.

Findings

Results show good air quality. Of the 50 air samples taken, only two had detectable lead, and other heavy metals were not found. Copper and zinc were present but in very low amounts.

Wind analysis indicates no significant pollution from the mine. Observations include consistent good air quality; no significant dust increase and low metal levels.

Bearing in mind that some local monitors may show higher pollution from nearby sources like household wood fires, bonfires or barbecues.

Read the full Air quality monitoring (air sampling) report (PDF 1.4MB).

Community-based smart sensors

The EPA sought expressions of interest from community members interested in having a smart sensor, also known as a PurpleAir monitor, installed on their property as part of our broader monitoring program. Expressions of interest for smart sensors have now closed.

We deployed 36 smart sensor air monitors at properties in the local area for community-based air monitoring.

Smart sensors measure airborne particulate matter (PM). PM describes solid particles suspended in air, including dust, smoke, pollen, and other organic and inorganic particles.

The sensors use laser particle counters that count particles in the air in a range of sizes. These particle counts are then used to estimate the PM2.5 air quality index (AQI). Data from the sensors is made available to the public in real-time via an online map. You can see on the map the sensors that we have already installed in the area reporting data in real-time.

These sensors provide us with a picture of regional dust, however they will not identify the source or composition of any dust. We deployed additional monitoring equipment and a range of monitoring techniques to provide a robust and comprehensive understanding of the air quality in the region.

The sensors provide indicative information about air quality and dust movement in the local area. It should be noted that the data provided by the sensors can be impacted by smoke from BBQ’s, wood heaters, extraction fans and air conditioners, and when foggy the sensors may measure water droplets in fog as particles, giving an incorrect reading.

More information about the smart sensors, including how to use the PurpleAir map, is available on the Environment and Heritage website

Measurement of metals in air and particles in air

The EPA has installed a comprehensive network of high-volume air samplers and multi-channel DustTraks in the area surrounding the Cadia mine. These provide scientifically robust insights into air quality.

DustTraks are an air monitoring device for reporting total suspended particles, PM10 and PM2.5 with a 1-hour averaging period. Go to the Air Quality NSW website for more information about current air quality for parts of the Central Tablelands. 

High-volume air samplers are a device for sampling a relatively large volume of air, through a filter paper to determine gravimetrically the amount of trapped particulate matter. The collected matter is analysed for total suspended particles and will be reported regularly.

Six directional high-volume air samplers were installed in January 2024 and are currently operational. Sample filters are analysed for total suspended particles as well as heavy metals including Arsenic, Cadmium, Copper, Mercury, Molybdenum, Nickel, Lead, Selenium and Zinc.

More high-volume air samplers and DustTraks will be added to this network. 

The information provided by the sensors and high-volume air samplers will be used to inform the EPA's regulatory activities.

Continuous monitoring of other air pollutants

DCCEEW has established an air monitoring station at Millthorpe on behalf of the EPA. This station continuously measures particles, visibility, some gaseous pollutants (carbon monoxide, nitrogen dioxide, ozone, sulfur dioxide), as well as meteorological variables. Data from the station is reported hourly as air quality category (AQC) ratings and are included in our Central Tablelands regional summary. Visit our air quality page to check the current air quality in Millthorpe. 

Information about this program is available on the Air Quality NSW website.

The EPA sampled surface soils at 30 public sites within the Cadia region on 12-14 July 2023. Soil at 0.5 metres was also sampled at these locations where possible.

All samples were analysed for lead, copper, cadmium, arsenic, nickel, zinc and selenium. We compared the results of the soil monitoring to the national health-based levels for public open space and residential land with accessible gardens and to soil metal concentrations prior to commencement of the operation of the Cadia gold mine.

No soils samples, at surface or at depth, had levels of metals above national health-based levels for public open space or residential land with accessible gardens. 

Metal concentrations were at a similar level to those observed prior to the operation of the Cadia gold mine.

This suggests that dust deposition from the mine has not increased metal concentrations in soil in the area. 

The EPA’s Expert Panel has reviewed the report and advised the conclusions were supported by the data.

No further soil sampling is proposed.

The EPA is conducting a sampling program along the Belubula River and surrounding waterways following reports of PFAS and other contaminants being detected in the river.

The EPA has conducted sampling in May and August 2024 and results from the sampling are available below.

We have shared the results of our sampling in the region with the NSW PFAS Technical Advisory Group for advice. The NSW PFAS Technical Advisory Group includes representatives from NSW Health, Department of Primary Industries and the NSW Department of Climate Change, Energy, the Environment and Water.

Finding PFAS in the environment does not mean there is a risk to human health or livestock. It is important to assess if there are exposure pathways through which people might ingest PFAS, such as drinking contaminated groundwater or consuming food products watered with contaminated groundwater.

NSW Health advises that water from rivers and creeks should not be used for drinking or cooking without appropriate treatment. Untreated water may contain disease causing micro-organisms, chemical contaminants or algal blooms. For more information visit Drinking surface water - Water quality (nsw.gov.au).

We will continue to monitor and review water quality in the region.

Findings May

On 30 May 2024, the EPA collected surface water samples from nine locations along Cadiangullong Creek, Flyers Creek and Belubula River. At the time of sampling, the EPA measured pH, electrical conductivity, dissolved oxygen, temperature and turbidity. Samples were also analysed for metals, total dissolved solids (TDS), nutrients, hydrocarbons and per-and poly-fluoroalkyl substances (PFAS).

Testing showed that surface water samples met current irrigation and livestock guidelines for metals and nutrients, though copper levels exceeded ecological guidelines in Cadiangullong Creek. No hydrocarbons were detected in any locations. No PFAS were detected in Cadiangullong and Flyers Creeks. PFOS levels were detected in the Belubula River that exceeded ecological guidelines.

Read the full  Surface water testing report (PDF 1.2MB) and the Belubula River water sampling results (PDF 2.4MB).

Findings August

On 20 and 21 August the EPA collected samples from 16 locations along the Belubula River and surrounding locations, both upstream and downstream of potential contamination sources.

Results show PFAS in 13 of the 16 sites sampled, 11 of which were above the ecological water quality guidelines. The highest PFOS concentrations were in Mackenzies Waterholes Creek and Cowriga Creek, with elevated levels also found in the Belubula River.  Surfactants, which are either natural or synthetic foam were detected in all samples. Aluminium exceeded the livestock drinking water guidelines in the Belubula River upstream of Blayney. Aluminium and copper concentrations exceeded ecological water quality guidelines at some sites. Read the full Surface water testing – 20 to 21 August sampling results report (PDF 2.3MB).

Groundwater sampling

Between 27 and 31 May 2024, the EPA collected groundwater samples from 12 monitoring bores. At the time of sampling, the EPA measured pH, electrical conductivity, dissolved oxygen and temperature. Samples were collected when stable parameters indicated a representative groundwater sample. Samples were also analysed for metals, total dissolved solids (TDS), nutrients, hydrocarbons and per-and poly-fluoroalkyl substances (PFAS).

Findings

Water samples met TDS guidelines for beef cattle, pigs and sheep, but some bores (MB112, MB2A, MB90, MN9A) exceeded the limit for poultry. Groundwater was generally suitable for irrigation, with minor exceedances in chloride and sulphate. Hydrocarbon levels were undetectable. PFAS levels, including PFOA and PFOS, were well below guidelines. Metal concentrations were mostly within safe limits, with minor arsenic and copper exceedances posing no significant risk to the environment or agriculture. Nutrient levels were within acceptable limits, though oxides of nitrogen (NOx) and reactive phosphorus exceeded guidelines in Cadiangullong Creek near the mine’s southwestern end.

Read the full Groundwater sampling report (PDF 10MB).

August 2023

Regular vent emission monitoring 

Cadia continues to undertake vent emission monitoring regularly and provide a monthly report on dust discharges from one of its main vents. Results for fortnightly sampling of metals in vent stack emissions are provided to the EPA. The EPA continues to receive and review these reports.

Independent health risk analysis 

The EPA required Cadia to provide an independent health risk analysis in the form of a human health impact assessment to the EPA. Cadia sought peer-review and made the report available on the Cadia website.

We reviewed the Air Quality Impact Assessment, which is a key input to the human health impact assessment, and identified a range of issues. The EPA then required the Air Quality Impact Assessment to be revised and resubmitted. The revised Air Quality Impact Assessment is currently being considered by the EPA.

Tailings dam dust mitigation

We required Cadia to provide a report on all reasonable and feasible dust mitigation options to manage the risk of dust from the tailings dam and conduct sampling. In response, Cadia has provided the report on options to manage the risk of dust from the tailings dam to the EPA. The EPA is reviewing the report.

July 2023

The EPA required Cadia to undertake dust emissions monitoring on Ventilation Rise 8 every fortnight and is receiving fortnightly reports on dust monitoring as required under the licence conditions. 

Read a copy of the letter sent to Cadia on 7 July 2023 and the media release issued 7July 2023 for more information about the monitoring being undertaken on Ventilation Rise 8.

All reports and information received by the EPA are being reviewed and will inform the EPA’s regulatory activities.

June 2023

On 21 June 2023, the EPA said Cadia must comply immediately with the Protection of the Environment (Clean Air) Regulation 2022 (the Clean Air Regulation), the Protection of the Environment Operations Act 1997, and its Environment Protection Licence (EPL), or face further regulatory action by the EPA.

This followed test results showing the mine’s main vent was releasing an unacceptable level of dust.

Several new conditions were added to the licence to address community and environmental concerns about impacts on air quality. The new conditions require Cadia to do the following:

  • Undertake vent emission monitoring regularly and provide a monthly report on dust discharge from one of its main vents.
  • Provide additional reports on lead dust fingerprinting research, analysis of dust impacts and sources, an independent health risk analysis, and an updated Air Quality Impact Assessment.
  • Undertake works to manage dust generation underground, in addition to conditions issued in April to manage the risk of dust from the tailings dam.
  • Provide monthly reports on works undertaken in relation to the dust suppression plan for the tailings dam that Cadia has implemented under the conditions issued in April 2023.

Read a copy of the letter sent to Cadia and the media release issued 21 June 2023 for more information.

Cadia responded with initial actions including adjusting their underground operations in order to be compliant. Cadia has also taken a number of actions in addition to lowering dust production levels including

  • installing additional dust sprays and spray curtains
  • re-configuring the dust extraction systems
  • sampling of the vent rise emissions as required by the latest variation to the mine’s licence
  • installing additional dust sampling instrumentation
  • accelerated additional dust filtration units currently on order 

Read the media release issued 30 June for more information.

May 2023

On 29 May 2023 the EPA issued Cadia mine with a final pollution Prevention Notice regarding the management of emissions of dust and other air pollutants. A draft licence variation was also issued on 19 May 2023 as part of a new investigation commenced by the EPA.

Read the media releases issued on 22 May 2023 and 29 May 2023 for more information.