The resources sector works to minimise air quality impacts resulting from operations for the health of communities and the environment
Air quality can be impacted by emissions from a range of sources, including transport, industry, agricultural and urban activities. The resources sector contributes to these emissions and understands the need to minimise air quality impacts resulting from operations for the health of communities and the environment.
Of all the emissions, dust (also known as particulate matter) is a key focus for communities and the government due to the potential impact it can have on human health and amenity. Dust is like microscopic balls that come in a number of forms and sizes.
For environmental and health purposes, dust is usually described by size and includes:
- Total Suspended Particulate matter (TSP): The total of all particles suspended in the air. Even the largest of these particles is barely half the width of a human hair;
- >PM10: Particle sized 10 microns in diameter and greater and a subset of TSP;
- PM10: Particle sized between 2.5 and 10 microns in diameter and a subset of TSP; and
- PM2.5: Particle sized 2.5 microns and smaller and a subset of both PM10 and TSP.
Source: US EPA, 2016.
Large dust particles (PM10 and greater) can be produced from a number of sources. In an urban area, PM10 results from lawn mowing, wind blowing over bare ground or pollination. For resource operations, PM10 results from activities like moving rock and soil with large machinery or by blasting, traffic on haul roads or wind blowing over dumps and stockpiles.
In comparison, small dust particles (PM2.5) are generally produced from combustion processes such as vehicle exhaust, wood stoves and fires, which are present in all domestic settings. Whilst for resource operations, PM2.5 is primarily produced from vehicle and mobile equipment exhausts. It is these particles that are generally identified as having the potential to result in health impacts.
Small particles generally remain suspended in the atmosphere for many days and can travel many hundreds of kilometres, while large particles tend to settle out quickly near the source. Given the often large distances between mine sites and communities in Queensland, air quality impacts from the resources sector are generally limited.
Air Quality Standards
The Queensland and Commonwealth governments have set a benchmark for background (ambient) air quality, based on independent national and international studies, to ensure the ongoing health and wellbeing for communities and the environment.
At the Commonwealth level, the National Environment Protection Measure for Ambient Air Quality establishes standards for a range of emissions, including dust particles. These standards have been adopted under Queensland law and are provided in the Environmental Protection (Air) Policy 2008.
Dust Management and Reporting
Dust levels across resource operations are continuously monitored and must be kept to below standards set under Queensland and Commonwealth law at sensitive receptors (e.g. residences). Dust emissions are managed through a combination of mine planning, minimising disturbed areas, undertaking continuous rehabilitation, limiting road haul distances and traffic, using enclosed conveyors, veneering loaded train wagons, amending operations based on adverse forecast weather conditions and real-time monitoring, using water sprays on stockpiles and water carts on unpaved roads. Whilst the list is long, the resources sector is serious about minimising its impacts on communities and the environment and are always looking for ways to improve its performance.
In addition to the wide range of management measures implemented across operations, the resources sector reports emissions, including dust, annually to the National Pollutant Inventory (NPI). This reporting scheme is intended to provide transparency to the public and assist government in identifying priorities for environmental policy and inform decision making.
It is important to note the NPI focusses on industry-related activities. Whilst other (e.g. diffuse) emissions are considered to a small extent, the NPI does not provide a complete representation of all sources of emissions across Australia or jurisdictions. As such, the data must be used with caution to avoid misrepresentation or misinterpretation.
QRC plays an important role in ensuring information released in the public domain, which represents activities undertaken by the resources sector, is factual and accurate. It is important for the community to understand what the numbers mean to them. In the case of the NPI, QRC provides information that the assumption that the level of dust recorded by resource operations equals the equivalent level of impact on the community and the environment is not accurate. Under normal working conditions, dust generated during operations is largely retained within the resource companies lease boundary and buffer lands.
QRC is currently working with its member companies and government to:
- Improve NPI reporting for the resources sector;
- Collate up-to-date data for other emission sources (beyond industry) to input into the NPI and deliver a complete representation of air emissions across jurisdictions; and
- Provide better information on NPI data for greater public understanding and interpretation.
Rail Corridor Coal Dust Management
The rail network across Queensland offers an efficient means for the resources sector and others to transport products to ports for export trade. There are five rail systems across Queensland that support the resources sector.
To minimise coal dust emissions (lift-off) during transit, all coal mines in Queensland undertake veneering of loaded train wagons. This process involves spraying a biodegradable non-toxic agent onto the loaded coal surface at the time of loading, which then binds the top layer of the coal surface together forming a flexible, protective layer.
Rail Corridor Coal Dust Monitoring
Approximately seven million tonnes of coal is currently exported from the Port of Brisbane from coal mines in the Clarence-Moreton and Surat Basins in southern Queensland via the Western–Metropolitan Rail System. The coal haulage starts just east of Miles, travels through Dalby, Toowoomba, Ipswich and the western and southern suburbs of Brisbane to the Port of Brisbane.
In response to community concern regarding the health and amenity impact of coal dust from coal haulage along the Western-Metropolitan Rail System, the Queensland Department of Science, Information Technology and Innovation was commissioned by QRC, on behalf of the mining companies utilising and service providers managing the network, to conduct independent dust monitoring along the rail corridor. The Department’s analysis was later validated through a peer review process.
Phase 1 monitoring, undertaken in 2013, indicated that rail transport, including coal haulage, was compliant with air quality criteria along the Western-Metropolitan Rail System with coal dust making up a minor fraction of total emissions. Although having met compliance criteria, mining companies and service providers voluntarily adopted the additional dust mitigation measures, such as veneering and load profiling, as outlined in the South West System Coal Dust Management Plan 2013 to further improve overall environmental performance and to address community concerns.
Phase 2 monitoring results, undertaken throughout 2014 and 2015, demonstrated that rail transport, including coal haulage, continued to meet air quality compliance criteria and make up only a very minor fraction of total emissions. The monitoring also highlighted that the implementation of additional mitigation measures had been highly effective in maintaining compliance and reducing the loss of coal dust from loaded rail wagons further during transport.
The peer reviews of the Department’s analyses found that monitoring was undertaken using an appropriate method and design, and that the weight of evidence confirms the conclusions in the reports are valid and well supported by the data.
The independent reports prepared by the Department of Science, Information Technology and Innovation and the peer review of these reports are provided below.
Monitoring continues along the Western–Metropolitan Rail System today.