Fuel Additive Little Threat to UK Groundwater

LONDON, United Kingdom, December 14, 2000 (ENS) - The UK Environment Agency has published a report on the extent of groundwater contamination by the petrol component methyl-tertiary-butyl-ether (MTBE).

MTBE was incorporated into motor fuels several years ago amid concern about the health and environmental effects from engine exhaust emissions. Oxygenate ether compounds such as MTBE improve combustion and hence air quality.


In the U.S., waste disposal sites, like the Lowry Landfill in Denver, Colorado, can leak liquid wastes into groundwater, as seen in this photo from the 1970s. (Two photos courtesy U.S. Environmental Protection Agency)
But in the United States, where the Clean Air Act directly led to MTBE's introduction in order to meet mandated octane levels, the fuel additive has become one of the most significant environmental pollutants through the contamination of drinking water.

While it may benefit air quality, poor management of stored fuel and leaks from underground tanks have brought major groundwater pollution problems.

The U.S. Environmental Protection Agency estimates that about 100,000 gasoline storage tanks leak chemicals into groundwater, a significant source of drinking water. In Santa Monica, California, wells supplying half the city's water have been closed because of dangerously high levels of MTBE.

Now U.S. regulatory authorities are seeking to remove the mandate for MTBE in fuels.

"Given the concerns expressed about MTBE in the United States, we believed it to be prudent to conduct a study into the potential risk to groundwater in England and Wales," said Dr. Alwyn Hart of the Environment Agency's National Centre for Groundwater and Contaminated Land.


Aging underground storage tanks can leak gasoline and other contaminants into groundwater.
"This is an important study, which is much more comprehensive than any other work in Europe to date," said Hart.

"It demonstrates that the situation with regard to MTBE in England and Wales is very different from that in the U.S."

Groundwater accounts for about one third of public water supplies in England and Wales and in the southeast of England this figure rises to over 70 percent.

In the UK and Europe the switch to unleaded fuels along with efforts to improve combustion has also lead to the introduction and use of ethers such as MTBE, primarily to achieve mandated octane levels.

But the Environment Agency's review concludes that MTBE is not a cause of major concern for public water supplies taken from groundwater.


This week's report concluded that MTBE posed little threat to the UK's groundwater supply. (Photo courtesy Environment Agency)
The report "A review of current MTBE usage and occurrence in groundwater of England and Wales" studied known MTBE pollution data and brings together information from the Agency, water companies, oil companies and fuel retailers.

It bases its positive conclusion on several factors

"The Agency hopes that publication of this report will contribute to a policy and operational debate on the use of fuel oxygenates based on sound science and a clear informed understanding," said Hart.