Power stations in Victoria must operate under an Environment Protection Authority Victoria (EPA) licence and ensure strict emission limits are adhered to or face prosecution for breaches of the Environment Protection Act 1970.
To obtain a licence, power station operators must go through an EPA approvals process which requires an air quality assessment to ensure they meet accepted environmental criteria designed to protect sensitive receptors such as residents, agriculture and ecosystems.
In Victoria, licence limits for power stations are determined specifically for each power plant to ensure ground level concentrations meet limits specified in the air quality management policy State Environment Protection Policy (Air Quality Management).
The licence limits are determined taking into account a number of factors including: stack height, emission pollution rates and the estimated local air quality impacts predicted by air pollution dispersion modelling. The focus is on protecting the receiving environment.
Environmental Justice Australia report
A table presented in a recent report released by Environmental Justice Australia (EJA) compares emission limits for coal-fired power plants from different parts of the world.
EPA licence limits are set as grams per minute and it is not a straightforward matter to convert to milligram per cubic metre, as EJA has presented.
Further, it is not known how far away sensitive receptors may be from these international sources.
Table 10 in the report also omits critical information; the table is missing the averaging period to which these limits apply. For example, the particle limits for Loy Yang A were higher because they were licensed as three-minute averages, whereas the limits for Loy Yang B and Yallourn were licensed as 30-minute averages.
Further, it is not stated by EJA whether the particle limits in the table are for total particles (as they are in Victoria’s case) or just for particulate matter (PM10 or PM2.5), which would be considerably lower.
It is also important to note that other countries set limits upfront, while EPA goes through an approval process which requires air quality assessments to arrive at site specific licence discharge limits.
Mercury levels in the Latrobe Valley
To look at mercury emissions from power stations and any impacts in the Latrobe Valley, EPA commissioned CSIRO in 2015 to undertake air pollution dispersion modelling to estimate the contribution and impact of atmospheric mercury in the Latrobe Valley.
The results show that the power stations contribute less than 1% to the total mercury concentrations modelled in the Latrobe Valley. Mercury concentrations are dominated by the atmospheric background and natural emissions from vegetation, soil and water.
It’s worth adding that as part of EPA's periodic licence review program, which is currently reviewing power station and coal processing licences, EPA intends to add mercury to power station air discharge tables to be in line with the Minamata Convention asking for it to be monitored.
Gippsland Lakes mercury
In May 2015, the Victorian Government commenced a field study into levels of mercury in fish from the Gippsland Lakes. The study aimed to address community concerns about mercury levels in fish, and if appropriate to provide reassurance to the community that fish sourced from the Lakes are safe to eat.
It aimed to provide up-to-date information regarding the mercury concentrations in recreationally (and commercially) important fish species from the region. Results of mercury concentrations in fish were made available to the community in September 2015 and indicated that fish in the Gippsland Lakes continue to have low levels of mercury, and are safe to eat in accordance with nationally set dietary advice about the number of serves of fish and seafood people should eat each week.
The full report can be found at: https://www2.health.vic.gov.au/public-health/environmental-health/environmental-health-in-the-community/mercury-in-fish/gippsland-lakes-study
Latrobe Valley air quality
EPA’s air quality data shows that air quality has been consistently good in the Latrobe Valley, which is consistent with long-term air quality data in the region. Overall, air quality in the Latrobe Valley is comparable to Geelong and metropolitan Melbourne.
In 2015 and 2016 most pollutants monitored by EPA in the Latrobe Valley (PM10, NO2, SO2, O3 and CO) met the national air quality standards (Ambient Air NEPM). Two days in 2015 and one day in 2016 exceeded the PM2.5 air quality standard, this was attributed to smoke from prescribed burning.
The various ambient air quality standards and investigation levels used by EPA are set at levels for the protection of human health and wellbeing from the sort of exposures that might be experienced by the general public.
As well, EPA is currently working with a panel of Latrobe Valley residents to discuss how air monitoring in the region continues into the future.
Panel members are co-designing the future of the air monitoring network run by EPA in the Latrobe Valley.
To date discussions have looked at what to measure, where air monitoring equipment might be stationed to best capture data in the region, and the time equipment might stay in a given location before moving to another.
Once the panel discussions conclude, EPA will then begin implementing the panel’s preferred air monitoring model in consultation with the community and council.
EPA anticipates the new air monitoring network in the Latrobe Valley will be established during 2017 and 2018.
EPA provides an interactive map, which covers the Latrobe Valley, that provides the community with a quick and reliable way to check local readings of air quality and obtain health advice on days when poor air quality is recorded.
Using data from EPA’s 19 air monitoring locations across metropolitan and regional Victoria, EPA AirWatch monitors a range of common pollutants in the air.
EPA’s ability to monitor Victoria’s air quality during statewide emergencies such as bushfires has also been boosted with the use of incident air monitoring equipment that can be readily deployed.
This equipment can be deployed within 24 hours and provides hourly air quality measurements and health advice directly to EPA’s website.