Letters warn of MTBE in wells

800-900 property owners are advised of findings at several locations


New state requirements for monitoring wells at gasoline stations and for notifying residents when the gasoline additive MTBE tests above the state action level have triggered letters to between 800 and 900 property owners near several sites in Carroll County, officials said.

Letters went out beginning Oct. 18 to landowners near two sites: a High's store on Route 140 in the 2100 block of Sandymount Road, and a 7-Eleven store in the 100 block of Hanover Pike near the Baltimore County line, said Charles L. Zeleski, assistant director of the county Health Department's environmental health bureau.

MTBE, or methyl tertiary butyl ether, is a suspected carcinogen whose effects in drinking water have not been determined.

It was detected at or above the reportable level - 20 parts per billion - on the two properties, he said. The county Health Department is sampling nearby residential water but has not found anything off the stations' property, he said.

Zeleski expects to be sending "many more" such letters, as gasoline stations file reports to the Maryland Department of the Environment's Oil Control Program.

Herbert M. Meade, program administrator of the Oil Control Program, said emergency regulations took effect in January that apply to areas of Maryland such as Carroll where the geology allows groundwater to travel freely through fractured rock.

These emergency regulations required gasoline stations to install monitoring wells, and sampling was to have been completed by Oct. 1 for MTBE, benzene and other contaminants linked to gasoline, Meade said.

Starting at the beginning of this month, the state by law must notify local health officials when MTBE and certain other gasoline components are found at action levels. The local officials must send certified letters to property owners within a half-mile radius, he said.

Meade's office sent a letter dated Oct. 18 to the Carroll Health Department about a third site, the Keymar Citgo at 1020 Francis Scott Key Highway.

Carroll has decided to send the letters in new cases even if they pre-date Oct. 1, Zeleski said. As of Friday, letters were being sent not only about the Keymar station, but also about a new site: the Finksburg Exxon in the 3000 block of Baltimore Blvd. (Route 140).

"The notification issue is something we take very seriously," he said. The state has set a health-advisory level of 20 parts per billion for MTBE.

The additive has been required by the Environmental Protection Agency since 1990 in states such as Maryland that have ozone pollution in the summer, because it makes gasoline burn more cleanly. Studies show that laboratory animals that inhaled MTBE at high levels can develop cancer. While some other gasoline components are known carcinogens, MTBE is of concern because it tends not to break down in the soil, officials said.

Plans for a study on behalf of the state of MTBE's effects in drinking water fell through, Meade said. But the EPA is to perform a study within two years of the effect of oxygenates such as MTBE in drinking water, he said.

In Maryland, the new high-risk groundwater area runs across the top of the state, from Cecil to Frederick counties, he said.

"We've been very pleased," Meade said. "Not pleased with what we're finding ... but pleased that we're finding it: that the regulations are working, and we are able to monitor and do things at the site to prevent the spread."

Zeleski said: "What the monitoring wells are intended to do is pick up from the area immediately around the tanks - an early-warning, early-detection system. In many cases, it will probably be the only contamination detected. What this means is ... we'll ... treat around the service station."

Underground tanks "very seldom leak anymore," he said, and the tanks are inspected. Both he and Meade said that today the source more often is the piping systems from the tanks or the vapor-recovery systems at the pump handle.

In Carroll in the past few years, carbon filters and other remediation measures were installed after MTBE showed up in wells in Finksburg and Hampstead, and at two stations in the Gamber area.

In Hampstead, Meade said investigators are focusing upon a leaking home-heating oil tank as the source of MTBE contamination in some 36 wells in the Hillcrest Avenue area, just east of the town border. The Tevis Oil Co. station there has been eliminated as a source, he said.

In Finksburg, the Shell Jiffy Mart at Suffolk Road and Route 140 was identified as the source of MTBE contamination there, and owner Stanley H. "Jack" Tevis III paid for carbon-filtration systems at several properties in the area.

Tevis has an experiment under way there using bacteria underground to gobble up the MTBE.

State officials are reserving comment on Tevis' experiment, but some initial sampling has been done, Meade said. "It's looking pretty good."

Carroll lists 94 open sites and 1,024 closed sites that showed some type of petroleum release, dating from 1985.

Zeleski said the open list includes all kinds of petroleum contamination and not necessarily of drinking water.

"We're going through the older files and following up ones that haven't been closed out yet," he said. The county is not sending letters in these cases, unless something new is found.

Occasionally, a site thought to have been cleared will resurface, as in Gamber where a lawsuit was filed by a would-be developer who drilled a test well and found MTBE.


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