Workers have collected more than 6,000 gallons of oil from a spill stretching across nine miles off the California coast.
The cleanup effort was being carried out 24 hours a day, officials said on Thursday.
The crude oil, authorities said earlier this week, spilled from a ruptured pipeline on the California coast.
The leak happened near Refugio State Beach, a protected state park, just before a major holiday weekend that marks the summer tourist season across the United States.
Investigators said that up to 105,000 gallons may have leaked from the broken pipeline. So far, as much as a fifth of that amount – 21,000 gallons – reached the sea, authorities said.
The extent of the leak is not certain as the pipeline was an underground one, according to experts.
The pipeline’s owner, Plains All American Pipeline, apologized for the spill. “We deeply, deeply regret that this incident has occurred at all. We apologize for the damage that it’s done to the wildlife and to the environment,” chief executive Greg L. Armstrong told media.
At the time of the leak, crude was flowing through the pipeline at the rate of 54,600 gallons an hour, the company said.
However, company officials didn’t answer questions from reporters about how long the pipe spilled oil before it was discovered and shut down.