Scott Fishwick from Ramboll Environ Australia was the lead air quality consultant in charge of preparing the air quality impact assessment for Hume Coal’s EIS.

Mr Fishwick said the main concerns regarding the project were dust emissions including fine particulates (PM10 and PM2.5), and the associated potential health impacts.

The accurate representation of weather conditions in the assessment, particularly the high speed westerly winds that occurs in the region between autumn and spring, was also of concern.

These concerns were addressed in the EIS.

“The results of the dispersion modelling undertaken for the Hume Coal Project presented in the air quality impact assessment highlight the potential impact of dust emissions from proposed operations would be very low relative to both applicable NSW EPA impact assessment criteria and existing dust levels at all locations beyond the Hume Coal Project boundary,” he said.

Dust emission calculations and dispersion modelling was conducted using two different weather datasets- one located at the Hume Coal Project site and the other at Moss Vale operated by the Bureau of Meteorology.  

By using two weather datasets, Mr Fishwick said Ramboll was able to quantify dust emissions from the Hume Coal Project under all weather conditions experienced in the Southern Highlands, including westerly wind gusts up to 100 km/hr.

Emissions of different dust particle sizes were quantified and assessed in the air quality impact assessment.  

Coarse dust particles (TSP) were assessed to quantify dust deposition impacts, while fine particles (PM10 and PM2.5) were assessed to quantify human health impacts.

Predictions were made for the impact of both PM10 and PM2.5 and were compared against air quality criteria set by the NSW Environment Protection Agency (EPA).

Model predictions were made across a 15km x 11km area located over the Hume Coal Project area, incorporating the towns of Berrima, Bowral, Burradoo, Medway, Moss Vale, New Berrima and Sutton Forest and 76 representative residential properties.

“The predicted dust concentrations are well below the relevant NSW EPA impact assessment criteria for maximum day and annual average at all surrounding residences,” Mr Fishwick said.

“The assessment concluded that appropriate dust mitigation measures are integrated into the Hume Coal Project design, supported by alignment with accepted international best practice dust control measures and the low level of predicted impacts in the surrounding environment.”

These mitigation measures will include the use of full enclosure and water sprays at coal conveyor transfer points, sizing and screening stations and the coal processing plant, use of water sprays at coal stockpiles and the full enclosure of coal wagons transporting product to Port Kembla.

Looking at a worst case scenario, Mr Fishwick said the concentration of dust particles in the air would still be less than the EPA’s assessment criteria.

Concentrations of dust are assessed in units of microgram per cubic meter (or μg/m³).

Mr Fishwick said the typical PM10 concentration recorded in the Southern Highlands for a given day was approximately 15μg/m³. 

The applicable NSW EPA assessment criteria for 24-hour average PM10 is 50μg/m³ and for annual average PM10 is 25μg/m³. 

The maximum 24-hour average concentrations of PM10 are predicted to be 0.5μg/m³ at Berrima, 0.1μg/m³ at Bowral, 0.5μg/m³ at Burradoo, 1.2μg/m³ at Medway, 0.1μg/m³ at Moss Vale, 3.5μg/m³ at New Berrima and 0.1μg/m³ at Sutton Forest.

He said the annual average PM10 concentrations associated with the Hume Coal Project were predicted to be 0.1μg/m³ at New Berrima and less than 0.1μg/m³ at Berrima, Bowral, Burradoo, Medway, Moss Vale and Sutton Forest.

“The air quality impact assessment also demonstrates that concentrations of TSP and PM2.5 are very low relative to existing concentrations and applicable NSW EPA assessment criteria.”

-Ramboll Environ Australia routinely undertake air quality dispersion modelling studies of air pollution emission sources to analyse air quality impacts on the surrounding environment.  Air pollution sources they undertake dispersion modelling for include mines, quarries, road tunnels, intermodal terminals, airports, manufacturing plants and farming operations. Ramboll conducts work for town planners, industrial operators, construction firms, government departments and community groups. While the specific assessment methodology will vary from project to project, the same procedural guidelines set by the NSW EPA are followed for every assessment, including the Hume Coal Project.