(CNN) – At its worst, the smell burns your nostrils and gives you a little nagging headache.
Stones at Refugio State Beach lay splattered with a jet black tar, like goo, which can only be crude oil.
An industrial sized trash bin of oily vegetation sits next to the beach. Bikinis and surfboards on once-pristine sandy shores have been replaced with people in Hazmat suits, digging in the dirt and picking up oil-laden sticks and plants.
The onshore pipeline behind this week’s Santa Barbara oil spill leaked more than 100,000 gallons of crude on coastal lands and into the ocean, the oil company said Thursday.
What caused the oil spill remains under investigation.
The underground oil pipeline was carrying 1,300 barrels an hour, below its maximum capacity of 2,000 barrels an hour, said Rick McMichael of Plains All American Pipeline.
Plains All American Pipeline is among the worst violators listed by the U.S. Pipeline and Hazardous Materials Administration. It surpassed all but four of more than 1,700 operators in reporting safety and maintenance infractions, the federal agency said.
The company has 175 federal safety and maintenance violations since 2006, responsible for more than 16,000 barrels in spills that have caused more than $23 million worth of property damage.
Plains has been committing money to safety improvements for the past seven years, said Pat Hutchins, the company’s senior director of safety.
Meanwhile, crews continued to clean beaches and coastal waters, and officials reported the leak killed an undisclosed number of lobsters, kelp bass and marine invertebrates. Six oil-soaked pelicans and one young sea lion were being rehabilitated.
As of Thursday night, vessels had skimmed 9,500 gallons of oily water from the ocean, McMichael said.
The cleanup could last months, officials said. For now, currents, tides and winds make the oil plume “a moving target” as it drifts offshore, said U.S. Coast Guard Capt. Jennifer Williams.
The size of the spill, which began contaminating California’s beaches Tuesday, is equivalent to the volume of water the average American residence uses in a year.
Houston-based Plains All American Pipeline estimated up to 105,000 gallons may have spilled from a broken pipe, based on the typical flow rate of oil and the elevation of the pipeline.
Since the pipeline is underground, it will take a few days to determine how much crude oil was actually spilled, said McMichael, who estimated 21,000 gallons of crude had gone into the Pacific Ocean, with the rest spilled on land.
This isn’t the first oil spill in Santa Barbara.
A spill in January 1969 became what was, at the time, the nation’s worst offshore oil disaster. Though this week’s spill is smaller, it still prompted California’s governor to declare a state of emergency in Santa Barbara County.
The 1969 disaster was so catastrophic that it gave birth to an environmental movement, a host of regulations against the oil and gas industry and a new commission to protect California’s coast, experts said.
In all, about 3 million gallons of oil spewed from a Union Oil drilling rig five miles off the coast of nearby Summerland, California. The pipe blowout cracked the seafloor, and the oil plume killed thousands of seabirds and “innumerable fish,” according to an analysis by the University of California, Santa Barbara
Subsequent U.S. oil spills were much larger, including the Exxon Valdez accident, which dumped 11 million gallons off Alaska’s shores in 1989, and the Deepwater Horizon spill, which put 210 million gallons in the Gulf of Mexico in 2010.
But the 1969 Santa Barbara spill energized a movement that led to new federal and state environmental laws and helped establish the first Earth Day the next year.
Plains All American Pipeline violated federal environmental violations 10 times between 2004 and 2007, when about 273,420 gallons of crude oil were discharged into waters or shorelines in Texas, Louisiana, Oklahoma and Kansas, the EPA said.
Most of the spills were caused by corrosion on pipe, the EPA said.
The oil company agreed to pay a $3.25 million civil penalty and spend $41 million to upgrade 10,420 miles of crude oil pipeline operated in the United States, the EPA said in 2010.
The environment remains a major concern around Refugio State Beach, which was completely desolate Thursday, as were its campgrounds, which are normally packed for Memorial Day weekend. The only sounds were the waves and the helicopter above, a buzzing reminder of the oily mess below.
