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The environmental impacts of reuse and disposal

Up to 20 million litres of used oil is believed to be being burned at low temperature, or used as a dust suppressant on unsealed roads, with or without some prior reprocessing or cleaning.

In 1999, the Ministry for the Environment commissioned work from Woodward Clyde (now UBS) on the environmental impacts of burning used oil and spreading it on roads. Woodward Clyde's findings are reported in Assessment of the effects of combustion and waste, oil and health effects associated with the used of waste oil as a dust suppressant and they formed the basis for discussion in Recovery, reuse and disposal of used oil in New Zealand: issues and options which looked at the following environmental issues:

Burning used oil

Low temperature burning of used oil generates significantly greater volumes of air pollutants than alternative fuels such as diesel. Impacts from individual burners fall within ambient air quality guidelines, as long as the used oil burned meets a particular standard and burners are operated correctly. At a national level, the disparity in the quantities of pollutants emitted from low temperature burners compared with high temperature kilns is very large. Overseas data indicates that dioxin emissions from the burning of used oil will be low and are unlikely to be a problem in New Zealand. National environmental standards for dioxin emissions to air are, however, being developed. Any facilities that burn used oil and which are found to have substantial emissions will have to comply with these standards.

Spreading used oil on roads

The application of used oil to roads poses some health and environmental risks over time. Oil is commonly applied near orchards, cattle races and houses in rural areas. Fruit from orchards near oiled roads has been identified as posing a particular health risk.

Processing used oil to remove contaminants

Processing used oil to remove contaminants produces highly toxic waste sludges that require special disposal procedures.

Options for managing the impacts of used oil

The Chief Inspector of Explosives and Dangerous Goods, Occupational Safety and Health Servicis has introduced a fuel specification for used oil for safety purposes. The used oil discussion document suggests that some additional degree of control may also be required for environmental and human health purposes and identifies options for control. These could be "input" controls such as additional fuel specifications, possibly linked to licensing of organisations reprocessing for use as a fuel, or emission (output) controls. The discussion document also identifies and discusses the relative merits of mechanisms for introducing controls, such as tighter fuel specifications, under the Resource Management Act 1991. National Environmental Standards would provide greater consistency of approach. Guidelines to councils would allow for flexibility where required, though they could not guarantee national consistency.

Submissions received on the discussion document

About 20 individuals and groups made submissions on the discussion document. Approximately half the submissions were from regional and local councils, and the remainder were from individuals with an interest in used oil or interest groups (for example, motor trades, vegetable growers). No formal submissions were received from oil companies. A formal analysis of the submissions is available from the Ministry for the Environment on request. The need for national leadership on used oil recovery was the most pronounced theme in the submissions, and this issue is currently being given priority by the Ministry for the Environment. Better recovery rates and more consistent management of disposal practices is intended to reduce the environment harm caused by used oil.

Last updated: 17 September 2007