Skills: Dispersion Modelling, Decision support systems and custom tools
Tomago Aluminium Smelter is operated by Tomago Aluminium Company (TAC) near Tomago in the Lower Hunter Valley Region in NSW. TAC operates an air quality monitoring program that consists of five ambient sulfur dioxide (SO2) monitoring stations and a 30m meteorological tower.
In recent years, a number of exceedances of the 24-hour average SO2 criterion were recorded at the two air quality monitoring sites located to the east of the smelter, although operations at the smelter had not changed.
TAC engaged Katestone to investigate the potential cause(s) of the exceedances.
This was done by:
- extensive analysis of the monitoring data (using in-house statistical analysis tools)
- analysis of the meteorological conditions under which exceedances occur
- dispersion modelling using multiple meteorological and dispersion models with varying configurations
- source apportionment
- emissions measurement (including in-stack measurements and fugitive emissions from roof vents )
- wind tunnel modelling
The work conducted by Katestone showed that the exceedances occurred during extended periods of strong westerly winds (prevalent in winter months) and interestingly no exceedances of the one hour average criterion were observed during this period. The modelling continued to show compliance during the exceedance periods.
Katestone has provided further assistance to TAC who is currently working with the regulator to provide future solutions.