Oil Tank Spills Peril Suburban Enclaves : Contamination: Defective facilities found to have pumped almost 4 million gallons of petroleum products into world environment in 53 separate events last year.

A soft rain filters down on rows of deserted suburban lawns. Among the few signs of human habitation, a faded American flag hangs limply over the garage door of one house, next to a basketball hoop with a ragged net.

A peculiar scent, almost sweet, like fresh paint, wafts by.

“Smell the product?” asks Ivan Lewis, a retired Navy officer with neatly trimmed gray hair whose house is just up the street, on higher ground. He wrinkles his nose. “I can smell the product here.”

“Product” is the term homeowners in the upscale Mantua section of Fairfax County, near Washington, have adopted from the owners of a nearby oil tank farm to describe the various liquids stored there: gasoline, diesel and aviation fuel.

The problem is, some of the 31 steel tanks on the 40-acre farm have sprung leaks.

“Unfortunately, this is not an isolated incident,” said Wendy Butler of the Environmental Protection Agency. “It’s one of those situations where we didn’t realize there were problems, and we’re discovering them as time goes along.”

A large amount of “product” has seeped into the ground underneath Mantua, apparently over a number of years before a sheen was first noticed on nearby Crook Branch creek in 1990. Estimates of the spill range from 100,000 gallons to a theoretical cumulative high of more than 2 million gallons. This lethal mixture has migrated into the water table and slowly oozed through at least 18 acres of prime suburban real estate.

The giant, invisible plume of toxic pollution already has driven away some homeowners. Others plan to follow.

According to the Oil Spill Intelligence Report of Arlington, Mass., defective storage tanks pumped almost 4 million gallons of petroleum products into the world environment in 53 separate incidents last year, not counting the massive spills during the 1991 Persian Gulf War. By comparison, 20 tanker incidents spilled some 27 million gallons into the marine environment.

In the United States, 2,000 to 3,000 oil spills originating from approximately 650,000 oil storage facilities have been reported to the federal government annually since 1982.

Public attention is riveted by images of major marine spills: oil-soaked birds and oil slicks on pristine beaches. But inland oil spills are largely unseen and tend to go ignored by all but those most directly affected.

Major spills in Pennsylvania and California in 1988 stirred congressional interest and resulted in movement toward tightening government regulation of such facilities. EPA officials say a final set of rules will be put into effect next summer.

That will be considerably too late for those most directly affected by the Fairfax spill--especially those living in the front-line Stockbridge subdivision of Mantua.

Although the exact source has not been pinned down, the seepage has been traced to one or more of nine tanks owned by Star Enterprise, a subsidiary owned jointly by Texaco Refining and Marketing Inc. and Saudi Refining Inc. Star shares the farm with three other oil companies: Chevron, Citgo and Amoco.

The facility holds a total of 73 million gallons of motor and aviation fuel and supplies 40% of the requirements of the Washington, D.C., metropolitan area, including Dulles International Airport.

Some 180 Mantua homeowners recently reached an out-of-court settlement with Star Enterprise. Although the terms were not made public as part of the agreement, sources put the monetary award at about $150 million. The company also has guaranteed the property value of about $150 million worth of real estate. To date, 12 owners have taken buyouts.

Since the seepage was discovered, the company has spent more than $20 million to upgrade its facilities, including building a new loading rack and bringing all previously underground transmission lines above ground.

In the meantime, Stockbridge has begun to look like a ghost town as residents move out.