On Tuesday, a ruptured pipeline spewed oil into waters off the coast of Santa Barbara County for several hours, creating an oil slick four miles wide, The L.A. Times reports. Coast Guard officials estimate some 21,000 gallons of oil spilled into the ocean before the leak was secured.

“Luckily the source has been stopped and now it’s just a cleanup effort,” Coast Guard Lt. Jonathan McCormick told KTLA. “Hopefully we can get that done quickly.”

The Santa Barbara Independent reports that emergency personnel began arriving at the site of the spill at around 11:30 a.m. after residents complained of “gas smells.” At around 3 p.m., the source of the leak had been contained.

According to county official Richard Abrams, the oil leaked from a pipe that was abandoned by Plains All American Pipeline some time ago.

“I guess there was still some product in there,” Abrams told the Independent.

[Image via AP Images//h/t Buzzfeed]