If this task order were a television show it would be LSI, Leak Scene Investigators. In the latest installment, Irvine, Calif.-based environmental engineering consulting firm England Geosystems, Inc., is acting as a an impartial, third-party evaluator for the Orange County District Attorney’s Office, monitoring how well Houston-based Shell Oil is fulfilling it’s promise to clean up contaminated soil near 130 Southern California gas stations. The job could cost more than $170 million.

England Geosystems, which performed the same task after a similar settlement with Atlantic Richfield Company, will work with the Orange County Health Care Agency, reviewing sample data from groundwater test wells ranging in depth from 15 to more than 100 ft, suggesting more detailed assessments where indicated, and ensuring that the five-year deadline is met. “We will concentrate on areas near drinking water sources, also known as sensitive receptors,” said England Geosystems project manager/geologist Fabio Minervini.

Tests include EPA Method 8260B analyses for the volatile organic compounds benzene, toluene, ethylbenzene, and total xylenes (BTEX), methyl-tert-butyl ether (MTBE), di-isopropyl ether (DIPE), ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), tert-butanol (TBA), and ethanol. If the laboratory analytical results detect concentrations of MTBE above 1 ppb, the sample is considered “impacted,” according to Minervini, suggesting that a gasoline leak has reached ground water.

The dramatic difference about the most recent settlement is that it was
reached before any gasoline containing MTBE, a suspected carcinogen, was detected in a drinking water production well. “It is important to prevent the drinking water from becoming contaminated in the first place because, once polluted, it is extremely expensive and difficult to clean up,” said District Attorney Tony Rackauckas in a press release when the settlement was announced on January 7. Shell Oil still faces a suit by the Orange County Water District.

“The potential problem is huge,” added Minervini during an interview later in the week. “If not properly and aggressively remediated the leaks from underground storage tank sites throughout Orange County have the potential to contaminate a significant portion of the ground water basin from which about half of the drinking water supply of Orange County is extracted for distribution to the public.”