State Hopes Firm Pays Large Fine Over Spill : Damages: Officials delay filing a lawsuit against Mobil Oil Corp. over pollution of the Santa Clara River in Valencia.

State officials said Monday that they will delay filing a massive lawsuit against Mobil Oil Corp. in hopes the company will agree to pay a large sum in damages for an oil spill in Valencia that fouled the Santa Clara River.

The state attorney general’s office was expected to sue Mobil before the anniversary of the pipeline spill--which occurred Jan. 31, 1991, a year ago Friday--to avoid problems with a one-year statute of limitations. However, attorneys for the state and for Mobil last week signed a stipulation that will preserve both sides’ rights to litigate the case if a settlement cannot be reached, according to spokesmen for both parties.

If the state ends up suing, “I can tell you that it’s likely that the damages will be in the multimillion dollars,” Deputy Atty. Gen. Michael Neville said.

“We’ll only settle the case if we can get a substantial settlement, and I think if we can’t do that, we will go to trial,” Neville said. He would not say what he considers substantial.

On Monday, the Los Angeles Regional Water Quality Control Board became Neville’s second client, voting to join the state Department of Fish and Game in seeking action against Mobil.

Mobil also faces a criminal complaint stemming from the 74,634-gallon spill. The Los Angeles district attorney’s office three weeks ago charged the firm with two felony violations of hazardous waste laws and two misdemeanor counts of polluting a waterway.

Mobil, which has not yet been arraigned in that case, faces maximum criminal penalties of $497,000.

According to state wildlife officials, oil gushing from the broken pipeline polluted a 15-mile reach of the Santa Clara River in Los Angeles and Ventura counties, killing 186 birds and damaging the habitat of two endangered species--a fish called the unarmored three-spine stickleback and a bird, the least Bell’s vireo.

It was the seventh major spill in five years from the 90-mile underground pipeline that carries heated crude oil from fields in Kern County to Mobil’s Torrance refinery. Mobil is in the process of replacing the line, which has an accident rate 10 times greater than the average for pipelines of similar age. Much of the pipeline is 20 years old or less, but some of it is 50 years old.

If no agreement is reached on civil damages, Neville said he expects to sue Mobil under the California Fish and Game Code, the federal Oil Pollution Act of 1990 and the California Water Code. He said that under the water code alone, Mobil could be liable for about $1.4 million in damages--or $20 for each gallon of oil spilled.

Neville said he sought the stipulation because one of the state’s claims might be jeopardized by delay of more than one year in filing the lawsuit. The stipulation provides that if negotiations fail and a suit is filed, Mobil gives up the right to invoke the statute of limitations.

The stipulation will “preserve the rights of both parties” in any future lawsuit, Mobil spokesman James Carbonetti said. He declined further comment on the case.

Neville acknowledged that the combination of the criminal case and the civil suit could raise an issue of double jeopardy since both charge Mobil with the same offense.

“It is an issue, and I would expect that Mobil would bring it up,” Neville said. But double jeopardy “will not be a problem,” he predicted.

Neville said the criminal case seeks to punish Mobil with fines, whereas civil damages “are in the nature of restitution or compensation . . . to make the victim whole, and the victim, in this case, is the wildlife and the habitat.”

He said experts working for the state are still defining the value of habitat loss.