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Trouble Underground : Natural Clay Layer Has Protected South Bay Water From Tank Leakage Contamination So Far, But Threat Is Real

August 28, 1988|DARYL KELLEY | Times Staff Writer

Nowhere in the South Bay have problems with leaking underground tanks become more apparent than along an industrialized strip of southern Gardena and eastern Torrance.

Since state law began to require testing of underground tanks in 1984, seven companies whose tanks have leaked pollutants into ground water have been identified along the 3-mile strip of Western Avenue.

On the strip's northern edge near Artesia Boulevard, a subsidiary of Morton Thiokol has spent three years and $700,000 to find the boundaries of a foot-thick plume of industrial solvent that flows from its property and beneath a neighbor's.

Nearby, Honeywell Inc. has drilled 20 wells in four years to gauge the movement of solvents and fuels leaked from tanks, and a camper shell manufacturer employs a worker full time to bail leaked solvent, once up to 4 feet thick, from 80 shallow wells.

To the south, leaking tanks at four other companies have added toxic chemicals to a soup of contaminants that underlie east Torrance and parts of Harbor Gateway.

State officials say the tank contamination--along with toxic plumes from the Mobil oil refinery, a former rubber plant on Del Amo Boulevard, Montrose Chemical Corp. and other nearby locations--threatens the South Bay's drinking-water basins.

No South Bay water well has yet been tainted. But industrial pollution has been found in the region's upper aquifer, a limited source of drinking water outside the Torrance area, officials say.

And state water officials say the contaminants could sink into two deeper drinking-water aquifers if not cleaned up.

Thick clay layers, a natural blessing, usually block the descent of pollution from shallow water basins into the deeper aquifers. But the so-called "impermeable clay" layers apparently have been penetrated or circumvented a few miles away in Santa Monica, Bellflower and South Gate, so water officials say the threat to the deepest water basins is real.

"There's no doubt about it--the potential is there to migrate down to drinking water," said Hank Yacoub, supervising toxics engineer for the Regional Water Quality Control Board in Los Angeles.

While local officials have known for years that shallow South Bay ground water is polluted, it is only since 1984--with a flurry of testing at oil refineries and recent enforcement of underground tank-testing laws--that they have begun to realize the magnitude of the problem.

Extensive contamination has been found beneath seven South Bay refineries, and underground storage tanks have leaked toxic chemicals at 187 locations from Los Angeles International Airport to the Port of Los Angeles.

"I don't think anyone anticipated we were going to run into the kinds of problems that we did. We thought we'd come across a couple of hot spots in the soil, but nothing along the lines of what we've found in the water," said Michael Bihn, a Torrance Redevelopment Agency planner.

"From what I've heard it's pretty much everywhere (in the South Bay)," Bihn said. "You get around industrial areas and you find this problem."

The problem's outlines will grow steadily clearer over the next two years, as owners of 5,000 to 6,000 South Bay underground tanks are pressed to comply with either a mid-1989 county deadline to test and monitor the containers or a mid-1990 Los Angeles city deadline.

Leaking tanks have already been discovered at 1,300 locations countywide. The tanks range from 500-gallon solvent and fuel tanks at small businesses to 12,000-gallon gasoline tanks at service stations and much larger solvent containers at industrial sites.

"We've got (leaks) all over the place. I don't even keep them in my head anymore. There's too many of them," said Carl Sjoberg, director of the county program that oversees tank testing in most South Bay cities.

In a recent interview, Sjoberg culled six South Bay cases from a batch of 1988 leak reports.

In Gardena, he said, layers of gasoline up to 3 feet thick were discovered floating atop ground water under two service stations. In Redondo Beach and Carson, leaks at gas stations had also reached water. And in Hawthorne, Northrop Corp. reported two leaks of solvents that had flowed into shallow pockets of water.

Leaks Reported

Through the end of July, 61 of the 187 leak cases had been reported in South Bay communities that are part of the city of Los Angeles, including San Pedro, Wilmington, Harbor City and the international airport area.

Thirty-three cases had been reported in Torrance, 24 in Carson, 17 in Gardena and 10 in Hawthorne. Other South Bay cities each had fewer than 10 reported leaks.

Countywide, about 30% of underground tanks have been tested and comply with local ordinances that require electronic monitoring to detect new leaks.

This compares with about 25% compliance in Los Angeles and 80% compliance in Torrance. Long Beach, Vernon and Santa Monica are the only other cities in the county that chose to enforce tank laws themselves. The county runs the tank program in unincorporated areas and in 80 cities.

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