Air Quality Fact Sheet

The Quarry currently employs several dust management measures to reduce the risk of fugitive dust at the site, including:

• reduced speed limits for all vehicles
• enclosed processing plant with negative pressure dust collection system with fixed water sprays with dust suppressants
• fixed water sprays on conveyor drop points and hopper loading
• fixed sprinklers along main internal roads
• water cart for dust suppression using both spray bars on all intemal roads and other potential dust generating areas and water cannon for wetting stockpiles.

An independent air quality impact assessment (AQIA) has been prepared to assess the impacts of the project having regard to the relevant Air Pollution Assessment Criteria (APAC).   

To inform this assessment, Boral undertook 12 months of ambient air quality monitoring (PM10, PM2.5 and RCS) to establish appropriate background concentrations with which to predict cumulative (Project plus background) concentrations. The location of the ambient air quality monitoring station is detailed in figure 1 below.

The monitoring results showed no unusually elevated concentrations for PM10, PM2.5 and RCS. In particular, the annual average concentrations of RCS were roughly 10 times below the air pollution assessment criteria (APAC) and the monitored concentrations for PM2.5 and P10 were below the corresponding ERS (Environmental Reference Standard / APAC concentrations during this period.

The AQIA considered air quality indicators associated with fugitive dust emissions from the Quarry operations, including:

• excavator and loader material handling
• truck and light vehicle movements on unsealed roads
• crushing and screening
• drilling and blasting
• wind erosion of stockpiles and exposed areas
• asphalt and concrete batching plant material transfer lines and baghouse.

Emissions of dust as PM10, PM2.5 and respirable crystalline silica (RCS) associated with the Project were estimated using published emission factors and quarrying activity intensity (e.g. throughput, vehicle kilometres travelled etc).

The dispersal of emissions to air from the Project and the resulting ground level concentrations at nearby sensitive receptors were modelled using the Victorian regulatory model, AERMOD.

Three scenarios based on likely worst case (maximum intensity and location of activities) development stages were modelled representing:

• Scenario 0: Base Case - Existing Operations
• Scenario 1: Project Year 5 – Quarry extension stage 3 (worst case construction)
• Scenario 2: Project Year 15 onwards – Quarry operation stage 7 and 8 (maximum operating conditions).

The risk of adverse impacts to air quality at the nearest sensitive receptors is predicted to below with the PM10 and PM2.5 24-hour average and annual average APAC's met in all cases except in those unusual cases where background 24-hour average PM10 conditions approach the APAC. The maximum increase in Project 24-hour average PM10 ground level concentrations over existing operations, at any receptor under both either Scenario 1 or 2, is predicted to be a small fraction of the PM10 APAC.

With the application of the proposed management and mitigation strategies, potential impacts on air quality due to the Project would be avoided, minimised or managed to required standards such that the health, wellbeing and amenity of residents and the local community would be protected from fugitive dust.

Compliance continuous PM10 and PM2.5 monitoring will be conducted in accordance with relevant Australian Standards at a location representative a sensitive receptor(s) predicted to potentially experience high particulate concentrations to demonstrate that dust emissions are being controlled adequately to meet relevant APACs.

Where monitoring indicates that ERS objectives are exceeded and the source of PM10 and/or PM2.5 is reasonably attributable to Quarry operations, work intensity will be reduced or ceased until such time that compliance with the ERS objectives can be achieved.