On May 19, 2015, an estimated 101,000 to 140,000 gallons of crude oil leaked from a ruptured pipeline on the north side of Highway 101 near Refugio State Beach in Santa Barbara County, California. Although the final estimate of spilled volume is still under investigation, it is estimated that 21,000 gallons drained into a culvert under the highway and entered the Pacific Ocean. To protect human health from the ingestion of contaminated seafood, a fisheries closure was recommended that evening by the Office of Environmental Health Hazard Assessment (OEHHA) and enacted by OSPR, per delegations established in Fish and Game Code §5456. On May 21, the closure area expanded significantly along the shoreline as well as 6 miles offshore, to encompass a total of 138 square miles.
According to regulation, if a closure is in effect for more than 48 hours upon spill notification, expedited testing of seafood must be performed before the closure can be lifted. Staff at OSPR, OEHHA, and CDFW’s Marine Region, collaboratively developed a robust sampling plan to test a variety of finfish and invertebrate species, as well as kelp, to inform fisheries closure decisions. In total, 361 finfish and (non-mussel) invertebrates, 341 mussel, and 36 kelp samples were collected and analyzed. All samples were submitted under chain of custody to the OSPR Laboratory Program (OLP) and processed, analyzed, and stored using OLP standard operating procedures and/or U.S. Environmental Protection Agency protocols.
OLP staff began processing all samples by preparing the tissue, which must be performed fastidiously and under clean room conditions (maintaining positive pressure, HEPA filtering, and using sanitized tools) for accurate results. Contamination could give false positives and lead to unnecessarily lengthening the duration of the fish closures. Further, improper technique or storage procedures could give false negatives and lead to incorrect results. The laboratory received frozen, whole bodied animals and vegetation, including some species novel to the lab such as sea cucumbers and sea urchins. All samples were rinsed and scrubbed to remove exterior debris and then weighed and measured. Tissue was removed and processed using various types of homogenizing equipment from meat grinders for large samples, Buchi for fillets, Polytron for smaller or to ugher species, and Cuisinart for vegetation. Once homogenized, the sample proceeded to the extraction process.
Tissues were extracted by pressurized fluid extraction, followed by gel permeation chromatography and silica clean up, and then analyzed for polycyclic aromatic hydrocarbons (PAHs)/alkylated homologs by GC/MS-SIM (SW846 EPA Method 8270 Mod). Results for 54 individual compounds or compound groups, including eight considered by OEHHA to be carcinogens, were reported. The OLP provided results and Quality Assurance documentation for all samples, including controls, showing that sample processing was reproducible, accurate, and free from cross contamination.
Laboratory results were sent to OEHHA, which compared reported carcinogenic PAH values to a pre-established Level of Concern (LOC). The LOC is a concentration that is considered to pose an unacceptable health risk if consumed at the stated rate and for a predicted duration. Mussels were the only species with carcinogenic PAH values above the LOC and were subsequently re-tested. Analysis of the third and final batch of mussel samples showed that the values had fallen below the LOC, and on June 29th, OEHHA recommended that CDFW rescind the fishery closure order. OEHHA released their full report, “Risk Assessment of Seafood Consumption Following the Refugio Beach Oil Spill Incident in Santa Barbara County, California” in December 2015. OLP staff worked nearly around the clock to process over 700 tissue samples and provide accurate results to expedite fishery closure decision making.