Managing Air and Water Quality at Cadia

• The assessment determined the potential risks to human health within the community surrounding Cadia from operating emissions (modelled from January 2022 – February 2023) and environmental sample data collected from a residential drinking water sampling program. The report reaffirms that Cadia is not responsible for lead or heavy metals where elevated risks have been identified.

• The report states building materials and drinking water system maintenance practices as the key source of metals.

• The findings of the Human Health Risk Assessment conducted by SAGE Environmental shows that Cadia is operating within established health standards, and the potential risk of emissions to human health is low.

• When assessing the report in collaboration with all other independent studies, it confirms that there is no impact on human health from metals in dust from Cadia's mine site.

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 lead isotope analysis and dust fingerprinting study show no evidence linking Cadia to the lead sampled in the district's rainwater tanks.

• For this study, 88 sludge samples that were collected by Cadia during the district water sampling program were examined against samples taken from Cadia's ore body, and other soil and rock samples from the surrounding area.

• 74 of the samples found no correlation with Cadia ore.

• While there were similar characteristics between the Cadia orebody and district soil samples in the remaining 14 samples, the amount of lead recorded in these 14 samples were at the lowest concentration of lead amongst all the sludge samples and at a level that is considered immaterial. Despite this fact, some media continue to suggest Cadia as the source of lead.

• The results of this isotope fingerprinting study correlates with the results from the district drinking water sampling program undertaken earlier this year in response to community concerns, the findings from the ANSTO 12-month air quality study, and current and historical monitoring data.

• 144 residences participated in Cadia’s Independent Community Water Sampling program.

• Eight residences return readings above Australian drinking water guidelines, with seven residences’ results attributed to building and/or plumbing materials.

• 95% of households had water that meets the Australian Drinking Water Guidelines.

• No clusters were identified or links determined to Cadia.

• The results of Cadia’s community drinking water program aligns with sampling conducted by NSW Health and the NSW EPA.

• These results also indicate the importance of maintaining tanks and tank water distribution systems in accordance with guidance provided by NSW Health.

• Cadia has released an updated Air Quality Dispersion Model conducted by Todoroski Air Sciences.

• The report presents air dispersion modelling for Cadia during the period January 2022 to February 2023.

• Using actual sampling data from the Cadia and ANSTO monitoring networks, the Air Quality Dispersion Model showed that site boundary and receptor point compliance levels are met, and no evidence linking Cadia to lead or metals sampled in community rainwater tanks. ​

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.