Initial results show at least some of the tar balls found on beaches in Ventura and Los Angeles counties came from remnants of the May 19 oil spill off Refugio State Beach on the Gaviota Coast of southern Santa Barbara County.
Plains All American Pipeline, which is responsible for the spill and subsequent cleanup efforts, released a portion of its lab results Monday.
Scientists have been working since earlier this month to provide chemical “fingerprints” for the tar balls to determine whether they originated from the local Line 901 leak or from natural oil seeps.
More than 50 samples were taken from the shoreline west of Gaviota and south to San Clemente Beach, and the U.S. Coast Guard collected another nine from locations along Manhattan Beach where tar balls were reportedly spotted last month.
“Analysis of initial samples suggests that some of the Line 901 released oil appears to have migrated over time to beaches in Ventura and Los Angeles Counties, along with oil from other sources, some of which has been confirmed to be from natural oil seeps,” Plains said in a statement.
Of six samples analyzed to date, results show two were consistent with oil from the Plains release and four were consistent with natural seep samples in the Santa Barbara region.
Results for the remaining three samples were pending, the oil company said.
Scientists from UC Santa Barbara and Woods Hole Oceanographic Institution in Massachusetts used oil fingerprinting to determine the source of shoreline oiling by industry, researchers and government and regulatory entities.
Once lab results are complete, sampling results will be posted on a Plains website.
The source of the May 19 oil spill — a portion of badly corroded, ruptured pipeline — is about a mile north of Refugio State Beach, or about 10 miles from the edge of Goleta and about 40 miles up the coast from the Ventura County line.
Initial Refugio oil spill cleanup efforts were nearly finished last week, but the long-term impacts are largely unknown.
— Noozhawk staff writer Gina Potthoff can be reached at gpotthoff@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.