Chemical That Cuts Smog May Threaten Water

It’s the chemical responsible for removing 520 tons of carbon monoxide every day from Southern California’s smoggy skies. It has helped slash the level of the dread cancer-causer benzene in gasoline.

But there is preliminary evidence that the good-guy chemical of California’s air pollution wars could in some cases become a dark prince on another pollution front--ground water contamination, state regulators say.

The chemical in question is MTBE, or methyl tertiary butyl ether, which is now present in an estimated 90% of the state’s gasoline as refineries have moved to meet increasingly stringent air pollution standards.

The recent discovery that the chemical has contaminated three municipal drinking-water wells in Santa Monica is raising questions about how far Gov. Pete Wilson’s administration should go in cutting back one of the most costly environmental programs in California--the 12-year, $1-billion cleanup of leaking underground gas tanks.

The fallout from the Santa Monica contamination has also injected a dose of urgency into the plan to conduct similar tests elsewhere. State water and health officials say more MTBE contamination is likely to be discovered when testing for the relatively little-known compound becomes mandatory later this year.

The finding confirms the need for vigilance, but not alarm, among water system operators, said a state health official. “This shows that if you have gasoline stations and domestic water wells nearby, you definitely have to consider possible contamination,” said Cliff Sharp, chief of field operations for the Division of Drinking Water and Environmental Management.

Santa Monica’s initial discovery of MTBE came in February, not long after state health officials recommended that the operators of public water systems begin monitoring water wells for the substance. The wells were promptly closed and Santa Monica officials have begun searching for the source of the pollution, which they suspect leached into a drinking-water aquifer from leaking gasoline tanks underground.

The community is the first in the state to find significant levels of the contaminant in drinking-water wells, following the discovery last year or much lower MTBE concentrations in several Orange County wells.

The three polluted wells are in a 6-acre property that Santa Monica owns outside its own borders, in the Los Angeles neighborhood of Mar Vista. Measurements at first were just above the 35 parts per billion level that regulators have set as a threshold for concern.

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As weeks went by, the level of the chemical increased so dramatically that its distinctive paint-thinner odor became obvious to workers at the Charnock Well Field. The concentration reached as high as 590 parts per billion. Two wells were closed about two weeks ago and a third was shut off last week, forcing municipal water officials to switch to a greater mixture of water imported by the Metropolitan Water District from the Colorado River and Northern California.

The Environmental Protection Agency has previously rated MTBE as a “possible” carcinogen, but knowledge about the chemical is evolving. Regulators said they expect it will be upgraded later this year to a “probable” trigger of cancer in humans.

With the contaminated wells shut down, water now being delivered to Santa Monica homes and offices is well within the recommended health safety standards, city officials say.

If the problem doesn’t abate, the city could be forced to abandon all the wells, which have produced 40% of Santa Monica’s water, said Brian Johnson, Santa Monica’s environmental programs coordinator.

The loss of the wells could cost as much as $2 million a year, an expense that eventually would be passed on to customers, said Craig Perkins, the city’s director of environmental and public works management.

Santa Monica officials suspect that one or two gas stations about 500 yards from the water wells could be the source of the contamination. The city will demand that the responsible party pay for cleanup and for the increased cost of importing water into Santa Monica, Perkins said.

John Farr, an engineer who heads a committee looking into the efficacy of the state’s underground gasoline-tank cleanup program, and several other experts said the Santa Monica discovery only confirms their earlier belief that state water officials, backed by the Wilson administration, went too far when they announced plans three months ago to curtail the program.

The announcement was based on a study that minimized the danger that leaking gas tanks posed to drinking water. Officials at the California Water Resources Control Board announced that the majority of more than 20,000 contaminated sites statewide probably would not have to be cleaned up after removal of leaking tanks. The board also recommended that its regional offices halt many cleanups more than 250 feet from drinking-water wells.

But the water board’s handpicked committee of academics and other experts believe the Santa Monica case reinforces their earlier beliefs that those recommendations were “simplistic . . . and not supported by good science,” according to Farr, the committee chairman.

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The Lawrence Livermore National Laboratory study used to justify the new policies focused on benzene. It found that the highly toxic hydrocarbon clings to soil and degrades naturally, or when cleanup crews apply natural substances, such as bacteria and oxygen. The dangers of MTBE--which moves much faster and is more persistent in ground water--were not even considered by the Livermore study.

“They totally ignored MTBEs and our committee had clearly identified that as an important issue,” Farr said. “I must say, I think they did that purposefully to try to make a point that underground tank cleanups had gone overboard.”

Lawrence Livermore researchers disputed the idea that they should have tended to the MTBE issue. They said research in other states has shown that drinking water is rarely contaminated by the additive.

Some officials at both the state health and water departments said they agree that more careful study is needed before redesigning the statewide tank cleanup effort. Farr agreed that some of the cleanup has been too costly and produced little benefit, but he called for a moderate approach “to protect water resources and to clean up based on good science, not just for the sake of cleaning up.”

Wilson appointee James M. Strock, the state Environmental Protection Agency chief, said the administration’s position has been misinterpreted and that it never intended a wholesale pullback from underground tank cleanups. “The fundamental goal of the whole program is to make sure that the drinking water is safe,” said Strock, “and that we should use updated science in setting priorities.”

The state Water Resources Control Board will hold two hearings next month on the underground tank issue and make any final decisions about how and when underground contamination should be removed.

State air officials said that they are concerned about the MTBE revelations, but that there is not yet any reason to curtail the use of the chemical. The oil industry has spent an estimated $10 billion to retrofit its refineries to use MTBE.

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The irony that MTBE has costs along with its benefits has not been lost on Santa Monica.

“This chemical is great cleaning the air. It removes something like the equivalent of 3 million cars from the road,” said Johnson, the Santa Monica environmental official. “But in the event it escapes beneath the surface, there are brand-new concerns. There is no such thing as a free lunch when it comes to the environment.”