Fuel Tanks at LAX Polluting Underground Water Table

A layer of jet fuel up to 5 feet thick has contaminated ground water beneath huge storage tanks at Los Angeles International Airport, and airport officials have begun a large-scale assessment of potential problems from toxic materials at LAX.

Early testing has shown that a regional water basin about 100 feet below ground level has experienced “gross contamination,” apparently from leaks in pipes or 500,000-gallon tanks at the airport’s main fuel-storage area, a city Fire Department investigator said.

Fuel from another airport site, operated by the Flying Tiger cargo airline, has also reached the water table, according to the state Regional Water Quality Control Board. In addition, fuel leaks discovered at two other locations at the airport have caused soil contamination 60 feet deep, and several smaller leaks have also been reported during the last year.

Officials said the fuel apparently has contaminated only the upper basin of ground water under the airport, which already was brackish and unusable because ocean water had filtered into it. And the leaks appear to pose no immediate threat to the nearest drinking water wells about three miles away in Inglewood, Hawthorne and the Lennox area.

Potential Threat to Wells

The contamination, however, is only 100 feet above the Silverado Aquifer, the coastal area’s major drinking water basin, and is a potential threat to municipal wells unless it is removed, according to Hank Yacoub, supervising engineer of the water board’s toxics division in Los Angeles.

“I think LAX is going to be a major contamination case,” Yacoub said. “We’ve got this huge airport with underground tanks we don’t even know about, and I think the problem is going to be much bigger than what we see today.”

Some oil companies and airlines believed to be responsible for the pollution have indicated a willingness to clean it up.

“We’re working with airport administrators . . . but I don’t know what will need to be done,” said Al Ward, executive director of LAX Fuel Corp., a consortium of 37 airlines that owns the large storage tanks located above the worst ground water contamination.

Prompted by state and federal laws--and a lengthening list of airport fuel tank leaks--officials at the city-run airport recently hired a consulting firm to determine the extent of contamination and to list all areas at the 3,600-acre LAX where toxic materials are stored.

“I’m sure we’re going to find some more leaks,” said Maurice Lahan, airport environmental officer, pointing to state estimates saying that about half of all underground tanks in California are unsound.

“We just don’t know how many tanks are out there. The airport acquired land that was formerly developed by gas stations, and paved it over. Underneath (the pavement) there are some underground tanks. And half of the ones we find are filled with something.”

The inventory of storage facilities, including about 100 known underground tanks, should be completed within three months, Lahan said. At that point, contamination problems will be further investigated through soil samples and the drilling of numerous test wells, he said, and a priority list for cleanup established.

Yacoub said the state will insist that the cleanup of contamination discovered under the airport’s main “tank farm,” about one-half mile west of LAX’s passenger terminals, begin by the end of the year. The state will require that all fuel floating on the ground water be pumped out and that the water then be treated until dissolved hydrocarbons are reduced to safe levels, he said.

The contamination at the cluster of 24 above-ground storage tanks was detected in 1986, when LAX Fuel Corp. bought 19 of the tanks from oil companies, officials said. Test wells on sites then owned by Union, Mobil and Shell oil companies revealed floating fuel between 6 inches and 5 1/2 feet thick atop the regional Gage Aquifer, said Fire Inspector Thomas L. Kinley, who has been monitoring the problem since it was reported to authorities last March.

It is not known how thick the layer of water is at the point of contamination, said John Joham, general manager of the Central and West Basin Water Replenishment District, which includes the airport area. But it is probably at least several feet thick, he said, and separated from the drinking water of the Silverado Aquifer below by layers of clay that would restrict the descent of dissolved jet fuel.

Kinley said no leaks are visible above ground, leading him to think that there is a break in an underground line leading to one of the tanks.

The Regional Water Quality Control Board has not yet required tests to determine the source and volume of the leaks and how far the contamination may have spread, Yacoub said.

“We realized we couldn’t do this piecemeal,” he said. “Shell and Flying Tiger came to us and said that other tanks were leaking, too--that we should take this airport project in its entirety.”

Mal M. Packer, the airport’s chief engineer, said LAX already had been planning to inventory its tank and hazardous waste sites to comply with state laws slowly being implemented. That program was approved by the Airport Commission in mid-1987, he said.

Two state laws passed in 1983 require local governments to inventory all underground tanks and inspect them for leaks. If leaks are found, tanks must be removed or replaced by others with double walls designed to catch leaking fuel. Monitoring wells must be installed even if no leaks are found.

7,000 Gallons Lost

In the Flying Tiger case, about 7,000 gallons of jet fuel were lost into the soil when a measuring rod was rammed through the bottom of an underground fiberglass tank, Kinley said. The fuel has reached the water table, Yacoub said.

Large leaks were also discovered when 10 underground tanks were being removed from two United Airlines sites last year, Kinley said. Three tanks and a pipe were found to be leaking, and soil was contaminated in both areas down to about 60 feet, he said.