Oil and Water Don't Mix.

Is Your Underground Storage Tank Leaking?

Sixteen million American homes use a total of some 11 billion gallons of heating oil a year, according to the U.S. Department of Energy. That's 700 gallons per household per year. And while many of those homes have their oil tanks tucked away in the basement, millions of others have them buried underground where, neglected, they constitute a subterranean hazard.

The laws governing underground storage tanks (USTs) are complicated. Tanks of more than 1,100 gallons, such as those found at gas stations, marinas and airports, are federally regulated by the Environmental Protection Agency (EPA); smaller tanks for home use, mainly concentrated in the Northeast, are not. In a 1989 report to Congress, the EPA concluded there were almost two million of these residential USTs scattered across the U.S. "The report also concluded that they're just as likely to leak as regulated ones," says Lois Epstein, an engineer with the Environmental Defense Fund.

The responsibility for home tanks falls on state and local governments, and although 35 states listed USTs as among their top 10 sources of groundwater pollution in 1996, many don't regulate them unless they're actually leaking. A few states have taken a more proactive approach. For instance, Maine passed a law to regulate all underground petroleum storage tanks regardless of their size or use. The Maine Department of Environmental Protection estimates that for every dollar spent on preventive measures, $3 of clean-up and third-party damage claim costs are avoided.

A Major Liability

"A leaking buried oil tank is the single most expensive problem that a homeowner can have," says home inspector Jeffrey May. Although tank testing may cause you to part with $300, a bad leak can ultimately cost upwards of $10,000. Many tanks were installed 20 to 30 years ago as suburban communities spread across the United States, and are now surpassing their supposed life span. But "the biggest liability are homes with tanks that for 50 or more years are unused and could have been leaking," May adds. Many of these switched from coal to oil shortly after World War II. "Older homes might have two or three tanks that no one knew about."

According to EPA's Office of Water, ground water is the source of drinking water for 95 percent of people living in rural areas, and half the nation's total population. So far this decade, states have reported over 371,000 confirmed releases from regulated underground storage tanks (approximately 60 percent of which affected local water quality). These numbers do not include the impact of the multitude of household fuel oil tanks unknown to homeowners or federally regulated by the EPA.

So how can you tell if a tank is buried on your property? Although a metal detector is a reliable method, some other signs to look for are: a vent pipe next to the house, a scar on the basement floor, pipelines coming through the basement wall, or a round metal plate or unidentified metal pipe with a cap protruding from the yard or patio. Many local fire departments now require permits and so may have a property's recent fuel storage history on record.

"People think tanks last forever because they never see the thing," says Cynthia Johnson, president of Tank Automation, Inc. But "USTs, like everything else, have a life span." There are several warning signs to indicate your tank may be leaking. Look for a change in the tank's water level, unexplained increases in oil consumption and oil loss during the off-season. Signs of spreading contamination might include dead or dying trees and bushes nearby, and oil odors near the tank or in your basement.

Unfortunately, signs aren't always so obvious. The wisest course is to have your tank, and if necessary the surrounding soil, tested periodically by a reputable company to catch any leaks early Oil. When the time comes, and it will, Johnson suggests replacing your UST with a fiberglass-coated steel tank (which doesn't corrode) or an aboveground one (which must still be inspected visually).

To alleviate the financial burden, many oil companies offer "tank protection" insurance that will pay for removal and clean-up costs. Homeowner's insurance may also provide coverage and local banks may provide financing or have special clean-up programs. Several state legislatures, including those in Oregon and Connecticut, are currently considering bills to grant homeowners assistance. For a link to individual state underground storage tank programs, visit www.epa.gov/ swerust1/states/statcon1.htm. CONTACT: Office of Underground Storage Tanks, EPA, 401 M Street SW, Washington, DC 20460/[phone].

JENNIFER BOGO is associate editor of E.