The department is undertaking an Air Quality Monitoring Study to assist the Environment Protection Authority (EPA) to ensure that Newcrest's Cadia Holdings Pty Ltd mine complies with its environmental obligations.
Aims of the program
The monitoring program aims to assess air quality in the Cadia Valley and identify possible sources of pollution in the valley. To achieve this, we will use a range of monitoring techniques primarily focused on assessing particle pollution.
The program aims to monitor airborne and deposited metals and to assess any contributions from Cadia Valley.
Specific program objectives are to:
- determine likely source areas contributing to airborne metals
- measure ambient air pollution in the valley to characterise the sources of air pollution
- conduct citizen science using low-cost sensors to engage the community in air pollution monitoring.
Sampling and analysis
The primary air quality metrics to be measured include:
- total suspended particles – total suspended particles are particles in the air that are generated by windblown dust, sea salt, earthworks, mining activities, industrial processes, motor vehicle engines and fires (total suspended particle composition includes metals such as copper, selenium, lead, zinc, nickel, mercury, arsenic and cadmium)
- particulate matter of 10µm or less PM10 and PM2.5 continuously
- local weather patterns.
How are we monitoring ?
Measurements of metals in air
Wind-directional high-volume samplers (D-HVAS) are being installed in Cadia Valley to monitor concentrations of trace metals in ambient air. The D-HVAS will be connected to wind sensors selected to sample total suspended particles, including emissions from mining activities. The D-HVAS sampling will support detailed analysis to identify the locations of potential sources of particles and metals relative to the sampling sites.
Continuous monitoring of other air pollutants
Ambient particulate matter concentrations are being continuously measured using DustTrak Aerosol Monitors (DustTraks) to provide more time-resolved information on variations in particle concentrations in Cadia Valley. The DustTrak monitors will complement the D-HVAS, providing an overview of overall particle pollution and how it varies throughout the day, along with our rural monitoring network.
In addition, the department has established an incident monitoring station at Millthorpe. This station continuously measures particles, visibility, some gaseous pollutants (CO, NOx, Ozone, SO2), as well as meteorological variables. Data from the site are reported hourly as air quality category (AQC) ratings and are included in our Central Tablelands regional summary. Please visit our air quality page to check the current air quality in Millthorpe.
Current air quality in Millthorpe
Automatic weather stations
The department's automatic weather stations will also be set up in the region. This will complement the meteorological measurements taken by the high-volume air samplers. The automatic weather stations and D-HVAS measurements, combined with measurements from the existing Cadia Valley weather stations, will provide continuous and detailed information on local weather conditions.
Low-cost sensing network
A network of low-cost sensors called PurpleAir sensors will supplement the department's monitoring program to provide valuable information on how particle pollution (PM10) may vary near Cadia Valley.
A PurpleAir sensor is a small device that uses laser particle counters and counts particles in the air. PurpleAir sensors are being installed throughout the Cadia Valley region, housed at the residences of community volunteers. Data from the low-cost sensors is made available to the public in real-time on an online map on the PurpleAir website.
These sensors will provide us with a picture of regional dust; however, they will not identify the source or composition of any dust. Our scientists are deploying additional monitoring equipment to provide a robust and comprehensive understanding of the air quality in the region.