Costs are running at $3 million a day, and there is no timetable for when the cleanup will be complete, Plains All American Pipeline's on-scene co-ordinator, Patrick Hodgins, told The Associated Press.
The company is responsible for footing the bill after a pipeline break near Santa Barbara forced the closure of two state beaches and prompted a fishing ban in the area.
Hodgins said the pipeline operator is not focused on the money.
"The responsibility here is to get it cleaned up as quickly as possible," he said.
About 76 per cent of 97 miles of coastline — mostly sandy beaches — have been cleared of oil. Crews are using putty knives and other tools to scrape oil off rocks and cobble beaches — a labour-intensive process that's dictated by tidal conditions.
"The beaches are fairly clean," said Coast Guard Capt. Jennifer Williams, one of two federal response co-ordinators. "We're making progress on the shoreline cleanup."
The May 19 spill occurred after an onshore pipeline operated by Texas-based Plains All American ruptured, leaking up to 101,000 gallons of crude.
About 21,000 gallons entered a storm drain and washed out to the Pacific Ocean off Santa Barbara County.
Wildlife experts have recovered 161 dead birds and 87 dead marine mammals, mostly sea lions. Another 106 animals were found coated in oil and are undergoing rehabilitation.
The toll of the spill is a sliver of the 1969 oil platform blowout off Santa Barbara County that blackened miles of coastline and killed thousands of shorebirds and other wildlife.
At the height of the cleanup, there were almost 1,200 people involved. Eighteen boats skimmed oil from the water while a pair of helicopters and a fixed-wing aircraft buzzed overhead. Crews have not used the aircraft for several days and the number of skimmers has been reduced to three.
Plains revised the total cleanup cost after initially pegging it at $69 million. Company spokeswoman Meredith Matthews said daily costs are expected to decrease as work progresses.
The cause of last month's break has not been determined, but documents released by federal regulators after the spill said testing conducted in early May found extensive external corrosion along some sections of the pipeline.
Hodgins declined to comment on the investigation by the federal Pipeline and Hazardous Materials Safety Administration.
As cleanup continued, the California Coastal Commission said at its monthly meeting Wednesday that it notified the company that it has opened its own investigation.
This story has been corrected to show the total cost so far is $62 million, not $69 million, per Plains All American Pipeline.Suggest a correction