Managing Air and Water Quality at Cadia

The Human Health Risk Assessment conducted by SAGE Environmental evaluated potential health risks associated with operating emissions (modelled from January 2022 to February 2023) and data from a residential drinking water sampling program. The report concluded that Cadia is not responsible for lead or heavy metals where elevated risks were identified. Instead, it highlights building materials and maintenance practices of drinking water systems as the primary sources of metals. The findings reaffirm that Cadia operates within established health standards, with the potential risk of emissions to human health deemed low. When reviewed alongside other independent studies, the assessment confirms no impact on human health from metals in dust originating from Cadia's mine site. The reports can be viewed in full below.

In July 2024, the Australian Nuclear Science and Technology Organisation (ANSTO) released the Final Report: Cadia Valley Operations PM2.5 Study, Stage 3 of its 24-month investigation into the major PM2.5 pollutants in the airshed around the Newmont Cadia (Cadia) mine. The study comprised of three stages:

• Stage 1 – Preliminary Desktop Study, which included a desktop analysis of relevant 2019-2020 data not collected by ANSTO to determine the sampling locations around the mine site for this report. The locations identified were Millthorpe, Mandurama, Panuara and Orange.

          

• Stage 2 – 12-month Sampling Study, which analysed PM2.5 levels, black carbon and chemical composition at the identified sites. This study revealed consistently low PM2.5 levels were recorded across all sites, with no annual National Environment Protection Measures (NEPM) exceedances and no significant contribution from the mine to overall PM2.5 concentrations.

• Stage 3 – Extension of 12-month Sampling Study, which included data from Stage 2, concluded that of the 823 air filters analysed over the 24 months, only two occasions of the daily PM2.5 standard of 25 µg/m³ were recorded, both in Orange in June 2022. Importantly, no exceedances were recorded at the three locations closer to the mine (Panuara, Millthorpe, and Mandurama). These findings indicate that Cadia mine does not significantly contribute to PM2.5 levels in the area, providing reassurance to residents about the quality of air in their community.

  The reports can be viewed in full below.

Results from a recent lead isotope analysis and dust fingerprinting study show no evidence linking Cadia to the lead detected in rainwater tanks across the district.

The study analysed 88 sludge samples collected by Cadia during the district water sampling program, comparing them to samples from Cadia’s ore body as well as other soil and rock samples from the surrounding area. Of these, 74 samples showed no correlation with Cadia's ore. In the remaining 14 samples, while some characteristics aligned with Cadia's ore body and district soil samples, the lead concentrations were the lowest recorded among all the sludge samples and considered immaterial.

These findings are consistent with results from the district drinking water sampling program, the ANSTO 12-month air quality study, and extensive current and historical monitoring data, reinforcing Cadia’s environmental accountability.

In 2023, in response to concerns raised by community regarding water quality in water tanks across the district, Cadia conducted a comprehensive water testing program.

During this program, Cadia tested 144 residences from across the district, with more than 95% of households with water quality that meet the Australian Drinking Water Guidelines. Eight residences returned readings above Australian Drinking Water Guidelines, and Cadia work with these households to conduct independent building reports to identify building and/or plumbing materials as the source of concern.

Importantly the program concluded that there were no drinking water quality clusters in the district and furthermore, there are no known links or causes from Cadia’s operations. The results of Cadia’s community drinking water program were transparently shared with relevant Government agencies and aligned with separate independent water sampling programs conducted by NSW Health and the NSW EPA at similar times.

Results from three independent testing programs indicated the importance of maintaining tanks and tank water distribution systems in accordance with guidance provided by NSW Health.

We monitor air quality at key locations on and adjacent to our mine site on a 24-hour basis. Our Air Quality Monitoring Program is managed in accordance with the Cadia Air Quality Monitoring Program, which was approved by the NSW Department of Planning and Environment (DPE). Cadia reports monthly on Air Quality and these reports are uploaded to our website.

What we monitor

• PM10 and PM2.5 Ambient Air Quality Monitoring – BAMs  (Beta Attenuation Monitors) provide continuous PM10 and PM2.5 particulate concentration measurements using the industry proven principle of beta ray attenuation. Eight BAM’s are in continuous operation at various locations around the Cadia district.  

• Dust Deposition Gauges - (DDG’s) are located at eleven sites around the Cadia District and the Cadia Dewatering Plant. The DDGs are analysed monthly for metals and total dissolved and insoluble solids.

• Visual Dust Monitoring - Visual dust is monitored during routine inspections and when complaints are received. Where excessive dust generation has been identified, mitigation measures are implemented.

• Meteorological Monitoring - We also utilise our on-site weather stations as part of our air quality monitoring program.

Data gathered from our monitors is used, in conjunction with weather forecasts, to plan each day’s operational activities. We change or reduce the operation of equipment to avoid or minimise potential contribution to elevated dust conditions on a case-by-case basis.

Monitoring Vent Emissions

Cadia conducts routine emissions testing at the surface ventilation system, which analyses the air quality of the exhausted air from our underground operations.

The latest monitoring results show that we are operating in full compliance with clean air regulations – the direct action we have taken to comply and curtail emissions from the mine's ventilation rise is having a positive effect and we intend to maintain this compliance.

These results have been provided to the NSW EPA and we continue to maintain regular contact with them on our actions to maintain compliant emissions from the vent rise.

The hot and humid conditions underground result in exhausted air being warm and saturated with moisture. On chilly mornings, the condensation from the exhaust air is often visible on the surface.