Mobil Oil to Clean Up Polluted Ground Water

Now that Mobil Oil Corp. has agreed to clean ground water polluted by leakage from its Torrance refinery, state regulators have turned their attention to another source of local ground-water contamination--chemicals under the site where American Honda Motor Co. is building its national headquarters.

In an order issued Monday, the state Regional Water Quality Control Board said its agreement with Mobil requires the firm to begin the cleanup of a 200-acre plume of gasoline-tainted ground water by Jan. 1, 1991. The plume stretches southeast from Mobil’s Torrance refinery.

Mobil officials, who already had acknowledged company responsibility for most of the pollution, said they were in general agreement with the board decision. “We’re satisfied with the order,” Mobil spokesman Greg Munakata said. Munakata said it is unclear exactly how much the cleanup will cost but estimated it will be in the millions of dollars.

Yet to be decided, however, is the cleanup of a second plume of polluted ground water that is fouled with industrial solvents. Board engineers trace the roughly 20-acre zone of contamination to the Honda site, a major city redevelopment project at Torrance Boulevard and Van Ness Avenue.

The pollution, which partly overlaps the contamination extending southeast from the Mobil refinery, was produced by some of the dozens of small businesses that formerly occupied the redevelopment land, according to engineers’ findings. Among them: Solvent Coatings Inc., The Body Shop, South Bay Disposal, South Bay Heating and Air, C & L Welding and Cal Automotive.

In view of this, state water board staff members will recommend that the board order Honda and the Torrance Redevelopment Agency to join ground-water cleanup efforts in the area sometime next year. Under the state water code, they say, the board can compel property owners to mitigate pollution on their land even if they didn’t cause it.

The prospect was attacked by a Honda lawyer when it was raised in connection with the Mobil cleanup at Monday’s meeting. San Francisco attorney Joseph Armao disputed the state agency’s position that solvent-based water contamination exists near the redevelopment site.

In an interview, Armao called the issue of solvent pollution a “red herring” that Mobil is using to avoid undertaking the ground-water cleanup alone.

“Mobil is trying to muddy the waters,” Armao said. He added however, that if it is proved that former occupants of the redevelopment site did cause contamination, Honda will pay its share of the cleanup costs.

Torrance City Atty. Kenneth Nelson declined to comment Tuesday on whether there is enough evidence to consider the redevelopment site a serious source of pollution.

“It’s an enormously complicated question,” Nelson said. “We’re not dealing with something that lends itself to simple answers.”

Speaking for Mobil, Munakata said that, at least in the area where the two different pollution plumes overlap, his company expects Honda and the city to pitch in. “Any kind of mitigation plan has got to take into account all the pollutants that may be present,” he said. “This is obviously going to require cooperation.”

Water board engineers say that, of the two contamination plumes, the gasoline pollution from the Mobil refinery is far larger and carries vastly higher concentrations of potentially harmful chemicals.

Mobil estimates that more than 50,000 barrels of fuels have leaked from refinery pipelines and tanks since the Torrance plant opened in 1929. Monitoring wells drilled by the company have registered 25-foot deep pools of gasoline and other hydrocarbons under the refinery, but Mobil officials say the pollution is less extensive than the wells suggest.

Despite the different natures of the two plumes, board engineers say pollutants from both represent potential threats to the Silverado aquifer, a drinking-water reserve more than 500 feet underground that is tapped by the city of Torrance.

“These pollutants dissolve, and then they go along with the ground water,” said Ju-Tseng Liu, a board engineer. “We want to clean all of this up before it reaches deeper aquifers because when it reaches deeper aquifers, it’s too late.”

Aquifers deep underground are generally separated from water closer to the surface by layers of clay, Liu said, but the clay layers sometimes have natural fissures or man-made perforations--from wells, for instance.