SAN DIEGO — The Exxon Valdez, the tanker responsible for the nation's worst oil spill, may have caused a 13-mile oil slick off the coast and won't be allowed into San Diego Bay for repairs until the Coast Guard can determine whether the crippled ship was the source, officials said late Monday.
The vessel's entry into the bay, scheduled for this morning, also was delayed by the discovery of large steel plates jutting downward from the hull that would have made it unable to clear the harbor bottom.
An Exxon Shipping Co. spokeswoman said the plates, which will have to be removed, were bent downward during the Valdez's 2,200-mile voyage from Prince William Sound in Alaska to San Diego.
Coast Guard officials late Monday said testing had confirmed the presence of oil in a slick within a mile of the Valdez, which was about 30 miles offshore. But the tests had not established the source of the spill.
Thin Sheen of Oil
"At this point it is still too early to confirm what caused the sheen on the water," Coast Guard Lt. Larry Solberg said late Monday night. "We just know there is a minute amount of a petroleum product."
A thin sheen of oil in some areas and a thicker slick in others was sighted Monday during a final inspection by the Coast Guard and other agencies that must give their approval before the Valdez enters port.
"We believe it is coming from the Valdez, off the port bow," said John Grant, a biologist with the California Department of Fish and Game, which joined the Coast Guard with the final inspection.
An Exxon official acknowledged that the oil could have come from the Valdez.
"I think that is a possibility, but it is one of many possibilities," said Carrie Chassin, a spokeswoman for the oil company. "It is undetermined at this point."
State Fish and Game officials said the slick posed no danger to marine life and was unlikely to reach local beaches. By late Monday, winds were blowing the oil parallel to the shoreline and dissipating it, a Coast Guard official said.
The Valdez, taken under tow by two tugs accompanied by a salvage boat on June 23 in Alaska, arrived about 30 miles off San Diego late Sunday, and was scheduled to dock at the National Steel & Shipbuilding Co. yard for a nine-month, $25 million repair job.
On March 24 the Valdez hit a reef and spilled 11 million gallons along the pristine Alaskan coast, polluting hundreds of miles of shoreline and killing thousands of marine animals. The cleanup there is continuing.
Before the ship was moved from Alaska, Exxon officials assured San Diego agencies and environmentalists that the vessel's tanks had been scrubbed and cleaned of oil. About 42 million gallons of crude oil that remained on board after the accident was transferred to other tankers, and tests showed about one part of oil per million parts of water remained in the ship's tanks, Exxon officials said.
Approved of Departure
The Coast Guard, Environmental Protection Agency, state of Alaska and other agencies had approved the departure, Chassin said.
"We think we did a very thorough inspection of the ship," she said. "A lot of people are going to be disappointed" if the slick came from the Valdez.
Environmentalists contacted Monday said they were alarmed by reports of the spill, but wanted the ship to dock as quickly and as safely as possible.
"It makes me feel that there may be residues and toxic substances that may be floating around in cracks of the ship and going into ecology systems in San Diego, but this is small potatoes compared to what they did in Prince William Sound," said Rick Nadeau, director of Greenpeace in San Diego. "We want to see this thing taken out of the water so it can't do any more damage to the ocean."
Late Monday, the Coast Guard reported that "a milky substance" was bubbling up near the damaged hull of the tanker, but officials did not know what the substance was.
Coast Guard officials earlier said one possible source of the slick was seawater discharged from the ship's tanks as it approached San Diego to lighten the ship's load, enabling it to clear the harbor bottom.
"They've been doing it since Friday, on their way down (from Northern California), and we've been flying over since it came into California and didn't see anything," said Don Montoro, a Coast Guard commander and director of the agency's marine safety operations.
Montoro said the oil also could have come from another vessel that had cleaned its tanks before leaving the harbor. The spill was in the main shipping lane.
"It could have been a pocket of oil that clung to the inside of the (Valdez), and was dislodged during the transit. Or it could have been old residue that . . . now has been dislodged," Coast Guard Lt. Solberg said. "It could still be from another ship, completely removed from the Valdez."