The Cadia region

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

The EPA conducted sampling in May, August and Oct 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 2024

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 2024

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).

Findings October 2024

On 22 and 23 October 2024, the EPA collected water samples from 20 locations along the Belubula River and nearby areas to investigate PFAS contamination. Samples were taken from key spots upstream and downstream of potential pollution sources, including quarries, a decommissioned abattoir, Blayney Sewage Treatment Plant, the Newmont Cadia gold mine, the current and former Cadia dewatering facilities, Blayney landfill and a composting and waste storage facility.

The results showed PFAS, particularly PFOS and PFOA, at 16 of the 20 sites. Elevated PFOS levels were detected downstream of the composting facility on Cowriga Creek, near the Blayney landfill, and downstream of the Cadia mine in Cadiangullong Creek. These levels exceeded ecological water quality guidelines in some areas but did not necessarily indicate a health risk. We are now liaising with Blayney Council, the owners of the composting facility and Cadia mine to arrange additional testing on-site. This is to better understand the potential source of PFAS detections at these sites and measures that can be put in place to mitigate the risks. Residents are advised not to use untreated river or creek water for drinking or cooking. The EPA is committed to updating the community as more information becomes available.

Read the full Surface water PFAS testing – 22 and 23 October report (PDF 822KB).

Findings December 2024

Results from the December surface water sampling were similar to previous sampling results with low levels of PFAS detected at 16 locations above ecological water quality guidelines.

Surface water sampling was also conducted at Cadia Gold Mine, Blayney Landfill and Australian Native Landscapes (ANL) composting facility (located on a former mine site). Cadia Mine PFOS levels ranged from 0.0003 to 0.0046 µg/L. Blayney Council landfill PFOS levels ranged from 0.0034 to 0.05 µg/L). ANL PFAS levels ranged from 0.63 µg/L to 1.5 µg/L).

Overall, surface water sampling in the catchment indicates a limited risk to livestock, irrigation and the surrounding environment.

Read the full Upper Belubula River catchment surface water and groundwater testing – 9 to 12 December 2024 report (PDF 3MB).

Groundwater sampling

The EPA conducted sampling from bores around the Cadia region. Sampling included measuring 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 May 2024

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 was 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).

Findings December 2024

Overall, the groundwater results indicate that most samples met the relevant Australian guidelines for livestock, irrigation, and ecological protection (ANZECC & ARMCANZ 2000, ANZG 2018, HEPA 2025). The groundwater quality appears to pose limited risk to livestock, irrigation, or the surrounding environment. PFOA results were mainly below the guideline values for drinking water and fresh water.

Read the full Upper Belubula River catchment surface water and groundwater testing – 9 to 12 December 2024 report (PDF 3MB).

Next steps

The EPA will continue to investigate further and understand the potential source of PFAS detections and measures that can be put in place to mitigate risks.

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 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 (TDS), total hardness, colour, turbidity, pH, nitrate, nitrite, sodium, fluoride and iodine. 

Findings

We received results for samples collected from the 97 properties. We 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.

On the day of sampling, there were mixed results for aesthetic values (including zinc, colour, copper, total dissolved solids (TDS), turbidity, hardness, iron and aluminium) in kitchen tap and tank water samples outside the range described in the ADWG. 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.

• Download the metals in water report (PDF 2MB)

Sediment in rainwater tanks

We understand testing sediment from rainwater tanks is important for the community. Samples of sediment from rainwater tanks were taken 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 were 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.

• Download the metals in sediment from rainwater tanks report (PDF 2MB)

Isotope testing

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.

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.

• Download the report (PDF 2MB)

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 reviewed the report and advised the conclusions were supported by the data.

No further soil sampling is proposed.