Banned chemical still a worry for Long Island drinking water

March 2008

U.S. Water News Online

NEW YORK — A gasoline additive banned statewide since 2004 over health and environmental concerns still threatens to taint Long Island's drinking water, state environmental regulators have found.

Methyl tertiary-butyl ether, or MTBE, was found at levels above the state drinking-water standard in 40 percent of 52 test wells at Long Island gasoline stations between 2002 and 2006, the state Department of Environmental Conservation said in a report.

Eight wells had more than 500 times as much MTBE as the drinking-water standard allows, according to the report. They have been or are being cleaned up, it said.

"It is evident that MTBE contamination is still a potential threat to source water for public water supply wells on Long Island," the department said, calling for further monitoring.

The study focused on Long Island because a 1998 survey found the area had the state's greatest share of gasoline spills with the potential to affect groundwater — the sole source of drinking water for more than 2.7 million residents of the island's Nassau and Suffolk counties.

MTBE was first added to gasoline from 1979. Its use has declined amid bans in New York and some other states.

The additive cuts air pollution from vehicle emissions, but it has became a source of environmental and health worries in its own right. The federal Environmental Protection Agency calls MTBE — which has been found in drinking water in at least 36 states — a potential human carcinogen at high doses.