Plains All American Pipeline, the company behind one of California's largest oil spills, said it was cleaning up a small separate spill near St. Louis.

Plains reported a spill from a pump station about 40 miles northeast of St. Louis late Friday. The company said about 100 barrels of oil spilled and some of that never migrated from the incident site.

"Plains sincerely regrets that this incident has occurred and apologizes for any inconvenience to area residents and impact to the environment," the company said in a Sunday statement. "The company has mobilized a full response, and we are committed to doing everything in our power to minimize the impact of this release."

The company said that, as of Sunday, about 2,700 feet of containment boom, nine vacuum trucks and more than 120 personnel were deployed to respond to the Missouri spill. Free oil that migrated to the area's Silver Creek is kept out of the larger Highland Silver Lake by containment boom.

The Missouri spill came nearly three months after Line 901, operated by Plains, ruptured along the California coast. Plains said during the weekend a multi-party team was sampling beaches over three counties in order to establish a reference point for beaches potentially affected by the May 19 spill.

The California pipeline system leaked as much as 2,500 barrels of oil and left residual contamination spread out over more than 100 miles along the state coast.

Preliminary findings from the federal Pipeline and Hazardous Materials Safety Administration said there was "extensive" corrosion on the pipeline system, with walls degraded by more than 70 percent of their original thickness in some locations.