D.A. Files Criminal Charges in Mobil Pipeline Spill : Pollution: Last year’s rupture in Valencia was the seventh in five years to occur on the 90-mile conduit. The oil damaged the Santa Clara River habitat of two endangered species.

The Los Angeles County district attorney’s office has filed criminal charges against Mobil Oil Corp. for a 74,634-gallon oil spill in Valencia last year that killed 186 birds and damaged the habitat of two endangered species in the Santa Clara River.

Mobil, the country’s second-biggest oil company, faces a maximum penalty of $497,000 if convicted on two felony counts of illegally disposing of hazardous waste and two misdemeanor counts of polluting a waterway, said Deputy Dist. Atty. David H. Guthman, head of the environmental crimes unit.

The company has already spent $10 million to clean up the Jan. 31 spill, which befouled 15 miles of the Santa Clara River in Los Angeles and Ventura counties, damaging the habitat of the unarmored three-spine stickleback, a fish, and the least Bell’s vireo, a bird.

The spill was the seventh in five years to occur on a 90-mile, underground pipeline that carried hot crude oil from Mobil’s Kern County oil fields to its Torrance refinery.

Mobil has already replaced 18 miles of the line, including the Valencia portion, and is scheduled to finish replacing the rest of the line by the end of this year, said Mobil spokesman James Carbonetti.

Although Mobil paid fines in connection with the previous leaks and in one case pleaded no contest to a misdemeanor charge of polluting a waterway, this is the first time the company has faced felony charges. Prosecutors decided to file the felony charges because of the extent of the damage and the fact that a 1990 environmental report on the replacement project stated there was a 99.8% chance that the existing line would rupture in the next five years, Guthman said.

Ironically, Mobil officials cited the high probability of leaks to win approval for the new pipeline over the objections of homeowners and environmentalists, who pointed to the company’s history of spills and the prospect of traffic congestion during the 18-month construction period. That admission will be used as evidence that the company was negligent, Guthman said.

But Mobil’s Carbonetti said Thursday that the company was unaware that the Valencia section of the pipeline was vulnerable to leaks. Six months before the spill, a hydrostatic test, in which water is pumped at high pressure through the pipeline to pinpoint weak spots, had failed to detect any problems in that section of the line, he said.

In addition to costlier fines, a felony conviction could expose the company to civil penalties and jeopardize its standing with insurance companies, said Assistant City Atty. Vincent B. Sato, who prosecuted Mobil on misdemeanor charges in connection with two 1988 ruptures that spilled 130,000 gallons in Encino and Sherman Oaks.

The state attorney general’s office also may seek civil penalties from Mobil once the state Department of Fish and Game completes a report on the spill, said Deputy Atty. Gen. Sara Russell.