FUEL-LEAK SCARES PARTLY EVAPORATE : STUDY PROMPTS STATE TO RETHINK COSTLY STORAGE TANK CLEANUPS.

Byline: Steven J. Gorman Daily News Staff Writer

Acting years ahead of a state-mandated deadline, Sun Valley truck stop proprietors Tom and Henry Manning began the process of replacing their old underground fuel storage tanks with newer, less leak-prone models in 1993.

No leaks were found in the five old tanks they dug up that December, but excavation crews discovered soil laced with gasoline and diesel fuel that had dribbled into the ground over the years as a result of overfilling.

Environmental consultants hired by the Mannings to evaluate the site concluded that the contamination presented no threat to ground water and should be left to break down naturally in the soil.

But inspectors for the Los Angeles Fire Department ordered a full-blown cleanup and extensive monitoring of the site. The inspectors, who enforce California's underground tank cleanup program in the city, said they had too little information about the extent of the spill.

Two years later - after $175,000 worth of digging, drilling, soil sampling and cleanup that produced a stack of paperwork several inches thick - the Manning Fuel truck stop finally received an environmentally clean bill of health from the Fire Department.

Although some of the Mannings' costs will be reimbursed through a state cleanup fund financed by a levy on tank owners, their out-of-pocket expenses remain at more than $100,000.

The irony for company President Tom Manning, who now runs his father's business at Tujunga Avenue and Penrose Street, is that all this might not have been necessary under a new cleanup policy taking shape in Sacramento.

``I'm sorry we had to do it,'' Manning said. ``I'm sorry we got caught in the trap. Maybe (a revised policy) will make the Fire Department see that they're not qualified to do this.''

Prompted by a recent study concluding that underground fuel tank leaks are far less damaging to the environment than once thought, the California Water Resources Control Board is re-evaluating a 13-year-old cleanup program which has cost tank owners more than $1 billion in cleanup costs. Much of that money has come from fees tank owners have to pay whether or not their tanks are leaking.

The program was aimed primarily at keeping drinking water free of toxic compounds left in the ground by fuel tank spills and leaks. Of special concern is a common component of fuel, benzene, a known human carcinogen.

The health threat presented by leaking fuel tanks, and benzene in particular, was once thought to be a major problem for drinking water systems that rely on ground water from wells.

But that has been called into question with a study commissioned by the state water board and released by Lawrence Livermore National Laboratory in the fall.

``The costs of cleaning up (underground tank sites) are often inappropriate when compared to the magnitude of the impact on ground water sources,'' the study concluded.

In 90 percent of some 1,200 ground water contamination cases reviewed by the laboratory, dissolved benzene extended no further than about 250 feet from its source. Where contamination was present, the ``plumes'' of leaking fuel were found to be stable or shrinking.

Of more than 12,000 public water supply wells tested statewide, only 48 were reported to have measurable benzene concentrations, the study said.

And the total amount of ground water statewide tainted by benzene concentrations above the state standard for tap water was so far below 1 percent that it was approaching zero.

The report concluded that with rare exceptions, subsurface microbes are able to gobble up gasoline and diesel fuel spilled underground, once the source of the leak has been removed.

Regulators in Sacramento reacted swiftly to the study's findings.

In December the state water board's executive director, Walt Petit, issued a letter to local regulators and the agency's nine regional offices urging them to back off from costly soil and ground water cleanups at ``low-risk'' sites.

But the study, partially funded by the oil industry, drew sharp criticism from environmental groups and some regulators, including the technical staff of the Los Angeles Regional Water Quality Control Board.

Critics said the study's methodology was flawed and that its recommendations, if adopted, could cause premature closure of some severe contamination cases.

``We are alarmed,'' said Bonnie Holmes, legislative director for the Sierra Club. ``It would be a huge loss in terms of water quality and water supplies in this state. We have a huge growth rate in California, and we need to depend on our ground water supplies.''

James DiGiorgio, a water resource control engineer and case manager for a special fund administered by the state to help pay for cleanups, said the Manning Fuel site seems to fit the profile of low-risk cases described in Petit's directive.

``This site appears to be consistent with what was said in that letter,'' DiGiorgio said. ``This site is not alone.''

Regulators say it is difficult to say exactly how many of California's active caseload of 20,000 leaking underground tank sites might fall into the class of low-risk sites best cleaned up by Mother Nature.

But David Rice, the chief author of the Lawrence Livermore study, said he expects cleanup costs statewide will be lowered by half.

James Giannopoulos, manager of the tank cleanup program for the state water board, estimated that more than 10 percent of all sites that once would have required a costly cleanup could ultimately be classified as low-risk.

Holmes of the Sierra Club said she fears a majority of the state's leaking tank sites will be abandoned without cleanup if the Lawrence Livermore recommendations are adopted.

She and others have also noted the uncertain safety level of the relatively new gasoline additive MTBE, which is believed to travel farther without breaking down as quickly as benzene.

Lawrence Livermore is embarking on a separate study of MTBE, and a state advisory board on underground storage tanks is expected to address the question in a report due to be made public around the end of this month.

The state water board, which has held public hearings on the issue in recent weeks, may be ready to adopt a new underground tank policy as early as fall, Giannopoulos said.

One thing that is not expected to change is the requirement that most of the state's single-shelled underground tanks be replaced by December 1998 with a double lining.

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Photo

PHOTO Tom Manning, president of Manning Fuel in Sun Valley, regrets his costly, perhaps unnecessary fuel storage cleanup.

Phil McCarten/Daily News