Healthy Environment, Healthy Community, Healthy Business

Environment Protection Authority

Environmental Issues

Air - NSW overview

Cleaner non-road diesel plant and equipment

Emissions from non-road diesel engines

a non-road diesel machine

A non-road diesel machine (reproduced with permission from CJD Equipment Pty Ltd)

Non-road diesel engines, such as rollers, graders, forklifts and tractors, are significant sources of fine-particle and oxides of nitrogen (NOx) pollution in metropolitan areas and regional cities. Around 100,000 (or 15 per cent) of the nation's non-road engines are located in the NSW Greater Metropolitan Region (GMR) and around 9,000 engines are purchased in the GMR every year. These engines account for about 5 to 10 per cent of fine particle pollution in the GMR and in some local government areas can contribute up to 45 per cent of fine-particle pollution.

Non-road diesel engines have long working lives and can increase fine-particle concentrations to levels significantly higher than background levels. This leads to higher exposure to pollution and greater health consequences for workers and residents.

Health effects of diesel particulate pollution

Fine-particle emissions from diesel exhaust, most being particles under 2.5 micrometers in diameter (PM2.5), are of particular concern because they can be inhaled deep into the lungs. Exposure to them is linked to premature death from heart and lung diseases, increased hospital admissions, asthma attacks, other respiratory symptoms and lost work days. There is no known safe threshold of exposure to PM2.5.

Diesel exhaust emissions also contain other harmful pollutants, such as oxides of nitrogen (i.e. nitrogen dioxide and nitric oxide), which contribute to formation of ground-level ozone.

Emission standards

Graph showing reduction in particle emissions

Reduction in particle emissions as US EPA non-road diesel engine standards are tightened over time

While on-road diesel engines sold in Australia, such as highway registered trucks and buses, are regulated to meet strict emission limits, there are no regulations or standards in place to control emissions from non-road diesel engines. A 2010 study (nonroaddieselrpt.pdf, 832KB) found that, nationally, the non-road diesel sector (excluding rail and marine transport) consumes a similar volume of automotive diesel oil as the on-road diesel vehicle sector. Regulated emissions limits for these engines have been enforced in the United States and the European Union since the mid-1990s and, more recently, in Canada, Japan, China, India and many other countries.

The US Environment Protection Agency (US EPA) emission standards are expressed as tiers and European Commission (EC) standards are expressed as stages, with progressively tighter emission standards phased-in for different size engines. The graph shows the reduction in particle emissions as the US standards have become tightened over time from Tier 1 to Tier 4. Currently, all new diesel equipment must conform to Tier 3 or Tier 4 in the US and Stage IIIA or Stage IIIB within the European Union (see Emission standards for non-road diesel, Chapter 4 of the 2010 study for further details on US and EU emission standards).

A 2009 survey of new engines purchased in Australia indicates that around 80 per cent conformed to US EPA Tier 2 standard or below.

National work

NSW is working with Commonwealth and other state governments on national measures to support the supply and purchase of cleaner non-road diesel engines.

A 2010 study (nonroaddieselrpt.pdf, 832KB) to gather information and scope possible actions for cleaner new non-road diesel engines in Australia found significant health benefits can be achieved by implementing national standards for emissions from non-road diesel engines and equipment. The study was funded by NSW and the Commonwealth, and some of its findings were:

  • particle-emission reductions achievable nationally by complying with the latest US standards are estimated to be between 5600 and 10,200 tonnes per annum in 2020, increasing to 7300 to 14,100 tonnes per annum in 2030
  • annual health benefits associated with PM10 and NOx emissions reductions in Australia are estimated to be in the range $2.5 to $4.7 billion by 2030
  • non-road diesel engines are all imported into Australia
  • in the absence of national emissions standards, there is a risk that continued voluntary uptake of cleaner engines could decline in the face of cheaper, non-compliant imports, for some engine categories.

The report: Cleaner non-road diesel engine project - identification and recommendation of measures to support the uptake of cleaner non-road diesel engines in Australia (nonroaddieselrpt.pdf, 832KB) provides further details.

Strategies to reduce non-road diesel emissions

Developing a national approach to emissions from non-road diesel engines may be a lengthy process and national emissions standards will not address pollution from existing fleets, which have long working lives. It is therefore important to consider other strategies that will result in more immediate reductions in emissions from non-road diesel engines.

The amount of exhaust emitted by a diesel engine is related to the level (if any) of conformance to US/EU or other international emissions standards, its age, size and how well it is maintained and operated. The following strategies can be applied to reduce exposure to diesel exhaust emissions:

  • purchasing engines that conform with the highest available US/EU standards (or other international standards)
  • ensuring only fuel that conforms with national fuel standards is used
  • ensuring engines are correctly repaired and maintained
  • improve an engine’s emission performance by fitting it with an exhaust-aftertreatment device
  • restricting unnecessary engine idling
  • locating plant and equipment away from sensitive populations (e.g. schools, hospitals, child-care facilities) or using best-performing equipment near these areas
  • locating plant and equipment away from residential areas and, when onsite work occurs near residential boarders, restricting access for non-essential vehicles and machinery
  • avoiding the onsite use of diesel- or petrol-powered generators by substituting mains electricity or battery powered equipment where possible.

Clean Machine Program

supplementary image

Particle filter installed on a City of Sydney chipper (reproduced with permission from the City of Sydney)

From 2011 to December 2014, the EPA ran the Clean Machine Program, which supported diesel emissions reductions from non-road diesel equipment by promoting procurement of lower emitting equipment, better worksite practices, and subsidising retrofitting of heavily polluting machines with exhaust emissions after-treatment devices (partial diesel particle filters). The program targeted diesel plant and equipment such as cranes, loaders, graders, dump trucks and tractors, used mainly in ports, quarries, waste facilities and construction.

More than 40 organisations throughout the GMR, including private businesses and local councils, participated in the program and the NSW Government provided almost $806,000 in subsidies to retrofit 141 diesel machines. It is estimated that these retrofits will reduce diesel particle emissions by about 37 tonnes over 10 years, yielding substantial public health benefits.

A number of the Clean Machine Program partners have voluntarily adopted policies to include emissions performance as criteria during procurement of new diesel equipment and selection of contractors. They also took on best practice measures to reduce emissions from worksites.

The EPA is currently working with a number of industry and local council partners to develop case studies demonstrating best practice measures that organisations can adopt to reduce diesel exhaust emissions.

Clean Machine Program 2011-2014

PM reduction and expenditure by region

RegionEmissions from nominated equipment
Emissions reduction after retrofit
Total cost
excl GST
EPA subsidy excl GST
Sydney Inner 2,339 1,169 106,400 84,475
Sydney Outer 2,212 1,106 341,208 279,932
Sydney Surrounds 919 459 169,640 144,729
Hunter 184 92 59,724 48,245
Illawarra 1,668 834 275,635 248,476
Total 7,323 3,661 952,609 805,859

PM reduction and expenditure by sector

SectorEmissions from nominated equipment
Emissions reduction after retrofit
Total cost
excl GST
EPA subsidy excl GST
Construction 2,075 1,037 325,716 275,802
Ports 3,260 1,630 233,822 198,842
Quarries 744 371 111,102 99,991
Waste 834 417 144,127 120,332
Local Government 409 204 137,841 110,890
Total 7,323 3,661 952,609 805,859
Page last updated: 20 July 2015