The High Risks of Ethanol

Adding high levels of ethanol to petrol increases the potential for underground fuel leaks and heightens the risk of severe groundwater contamination, according to a leading researcher in the field.

UNSW academic Dr Robert Niven, from the School of Civil Engineering at the Australian Defence Force Academy, is a specialist researcher in soil and groundwater contamination. He has branded the sale of ethanol- enriched petrol by independent retailers in Sydney and Wollongong, reportedly at levels above 10%, as "environmentally irresponsible".

"Unlike petrol, ethanol and ethanol-enriched petrol conduct electricity", Dr Niven says. "This can increase the corrosion of the steel underground storage tanks in which petroleum fuels are commonly stored.

"In addition, underground fuel feed lines, pump stations and filling points are unlikely to have been designed for ethanol-enriched fuel mixtures - which also increases the risk of leakage into surrounding soils.

"Once in the soil, ethanol-enriched fuel will migrate to the water table more rapidly than ethanol-free fuels, and spread more widely on it. And, once in contact with the groundwater or surface water, the presence of ethanol increases the solubility of petrol constituents, in particular the more hazardous constituents such as benzene. This can lead to significant concentrations of hazardous compounds in the vicinity of the spill.

"Contact with high-ethanol fuel can also cause the remobilisation of existing petrol spills, which are common at many service stations. In addition, high levels of ethanol are known to reduce the ability of microorganisms to break down petroleum contaminants, which works against the ability of the natural environment to restore itself.

"The net effect is to potentially double the size of the 'dissolved plume' of petrol contaminated groundwater, thereby substantially increasing the risk of human or ecological exposure to the contaminants."

Dr Niven said that operators of small, independent service stations were unlikely to have the financial resources needed to conduct large-scale contaminated site remediation. Furthermore, in comparison to the major oil companies, they may be less concerned about protection of their corporate "brand name".

"There is therefore a real danger of the formation of 'orphan' contaminated sites, due to operator bankruptcies," Dr Niven said. "The liability for clean-up would then be borne by the local council and/or the NSW government".

Dr Niven warns that owners and operators of service stations selling these fuels are running serious liability risks, and may be in contravention of the NSW Protection of the Environment Operations Act and the NSW Contaminated Land Management Act.

Dr Niven conducts research on both the fundamental properties of oil-contaminated soils, and innovative methods for their cleanup. He has conducted investigations and cleanups of dozens of service station sites throughout NSW, on behalf of major oil companies and independent operators. He was recently awarded a Fulbright fellowship to further pursue his research, in conjunction with three leading academics in the US.

Contact Details: Robert Niven, tel. (02) 6268 8335 or Judy Brookman, UNSW Media Manager, tel. (02) 9385 3249 or mob. 0421 061 251.