Minimising particulate pollution at coal mines

There is community concern about the impacts on health and amenity associated with particulate pollution from coal mining in NSW. The EPA has undertaken a range of initiatives and actions to minimise this pollution.

In late August 2010, the EPA commenced a joint compliance audit program with the then Department of Planning and Infrastructure and Department of Trade and Investment, Regional Infrastructure and Services.

The program

  • assessed the level of compliance with requirements to manage fugitive particulate matter emissions
  • encouraged improved environmental performance with reference to best management practice.

A total of 9 coal mines were audited (7 in the Hunter Valley and 1 each in the Gunnedah and Western coal fields).

Download the audit report: Environmental compliance and performance report - Management of dust from coal mines (PDF 1.2 MB)

Katestone Environmental was commissioned to review coal mining activities in the Greater Metropolitan Region (GMR) of NSW. The scope of the study was to

  • identify the major sources of particulate matter emissions from coal mines
  • identify operational practices and emission controls for minimising particulate pollution from coal mining
  • review international best practice measures to prevent and minimise particulate matter emissions from all activities associated with NSW coal mines, including land rehabilitation, and compare these with measures used at NSW coal mines
  • recommend the adoption of international best practice measures that could be practicably implemented in NSW at existing and proposed coal mines, and estimate the likely reduction in particulate matter emissions from adopting these
  • estimate the costs associated with adopting each international best practice measure

The report was finalised in June 2011 and made the following key conclusions

  • significant reductions in emissions of particulate matter could be achieved by applying best practice control measures that were technically and economically feasible
  • the top 5 sources of PM10 from GMR coal mines were wheel-generated dust, wind erosion of overburden (rock and soil), bulldozers on overburden, blasting, and trucks loading and dumping overburden
  • PM10 emissions from GMR coal mines could be reduced by almost 50% with application of best practice, but at significant cost
  • haul roads accounted for almost 40% of PM10 emissions from mines; the greatest reduction would be achieved by applying suppressants to haul roads, which could reduce emissions by 21% at a cost of $59 million a year

Download the report: NSW Coal Mining Benchmarking Study: International Best Practice Measures to Prevent and/or Minimise Emissions of Particulate Matter from Coal Mining (PDF 4.5 MB) and appendices (PDF 2.3 MB)

One of the key recommendations of the Katestone report was that each mine should carry out a site-specific determination of best management practice to reduce particulate emissions from the mine site.

The Dust Stop program

  • ensures that each coal mine implements the most reasonable and feasible particulate control options
  • was implemented through a series of pollution reduction programs attached to each coal mine licence

A pollution reduction program is a legally binding instrument that is attached to the environment protection licence issued by the EPA to industries, in this case, coal mines. Copies of each coal mine licence are available on the EPA's public register.

Under Dust Stop, pollution reduction programs were issued to all NSW coal mines throughout 2011 and 2012, and required the mines to

  • prepare a report comparing their current operation with international best practice
  • report on the practicability of implementing each best practice measure and provide a timetable for implementing suitable measures.

The details that were required in each report were set out in a guideline referred to in the pollution reduction program.

Download the guideline: Coal Mine Particulate Matter Control: Best Practice Site-specific determination guideline (PDF 80 KB)

Copies of each report are now available on the mines' websites.

The reports showed various best practice measures were already being used by mines to reduce dust, however, there was more work that could be done, including

  • increasing haul road watering
  • investigating best practice measures for loading and dumping overburden
  • stabilising exposed areas

The reports support the findings in the Katestone benchmarking report that wheel-generated dust in the mines is the biggest source of fine dust particles on most mine sites.

Additional pollution reduction programs

These main sources of dust became the focus of 4 additional pollution reduction programs issued to all NSW open cut mines in 2013 and 2014.

Pollution Reduction Program 1 required all open cut mines to achieve 80% control of wheel generated dust; and to monitor and report on their results by August 2014. This level of control is generally achieved by watering haul roads and by applying chemical dust suppressants.

The successful completion of this pollution reduction program in 2014 resulted in

  • all open cut mines achieving a dust control efficiency of 80% or more
  • an estimated reduction of about 20,000 tonnes of particulate matter per annum

The claimed improvements are being verified by visual observation from helicopter and ground under the EPA's Dust Buster campaign. All mines have also been encouraged to carry out periodic quantitative assessment of dust control efficiency as part of their individual air quality management programs.

Pollution Reduction Program 2 required all open cut coal mines to

  • alter or cease their handling of soil and rock waste during adverse weather conditions
  • monitor the outcomes of this action

The EPA advised industry to implement management practices based on predicted and prevailing weather conditions and dust levels, using both visual and quantitative assessment to ensure elevated dust levels were not experienced during adverse weather.

The EPA is working with the open cut coal mine industry to achieve a greater consistency between each site.

Pollution Reduction Program 3 required a trial of best practice measures for reducing the levels of dust from disturbing and handling soil and rock waste. The trial found

  • particulate matter reductions of an estimated 40% to 70% could be achieved by using water during loading and dumping activities (this best practice measure was limited by water availability and safety implications)
  • minimising drop heights during loading and dumping activities significantly reduced the dust plume

The EPA has advised industry that minimising overburden drop heights is now considered best practice and that licence conditions will be used to enforce the application of this best practice measure.

The EPA continues to work with industry to ensure that best management practice and technology is implemented at each site, particularly during adverse weather.

Pollution Reduction Program 4 was issued in 2014 and required all open cut mines to assess their wind-erosion exposed areas against pre-determined benchmarks. This was a major initiative by the EPA into an area traditionally managed by other agencies, made necessary by an ever-expanding area of exposed soil and rock, particularly in the Hunter Valley.

The EPA worked with a number of mines in the Hunter Valley whose exposed area exceeded the pre-determined benchmark. The works undertaken

  • ensured that the exposed areas were stabilised to prevent further wind erosion
  • are estimated to have reduced exposed areas by approximately 1,800 tonnes per year

Copies of each report are now available on the mines' websites.

The EPA, in consultation with the mining industry and Department of Planning and Environment, has developed an Interim Dust Assessment Handbook to assist mine operators in the Hunter Valley to improve air quality.

The Interim Handbook is designed for use by mining equipment operators, supervisors and superintendents and environmental regulators. The handbook

  • contains photographs that illustrate when to consider operational changes to minimise or reduce dust
  • assists in identifying whether mining activities are being conducted in a proper and efficient manner
  • lists a series of factors to consider in assessing whether operational changes are required
  • applies to vehicles on haul roads and to drilling rigs, but may be updated to cover other mining activities in the future
  • is a 'glove-box' sized document made of durable materials to withstand day-to-day use in the mining environment.

Copies of this publication can be purchased from the NSW Government Online Bookshop at www.shop.nsw.gov.au or by calling the EPA's Environment Line on 131 555.

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