Oil Spill Fingerprints

November 16, 2023

Question: Can CDFW track down the source of a mysterious oil spill?

Answer: Within CDFW is the Office of Spill Prevention and Response (OSPR). That’s where the Petroleum Chemistry Lab (PCL) has a staff of chemists whose primary task is determining where spilled oil came from. Hundreds of oil spills or leaks occur in the state annually, with incidents ranging from tanker truck rollovers to pipeline leaks to natural offshore seeps. When it’s not obvious which company or facility is the source of a spill, the PCL steps in.

Petroleum is a mixture of thousands of individual components that indicate the geographic location, age, thermal characteristics and organisms of a geologic oil reservoir. These factors create unique signatures or fingerprints that help chemists identify one oil sample from another. When oil is collected by CDFW during an investigation, OSPR’s scientists can identify the source of that spill by comparing the fingerprints to samples from the most likely potential sources. That work can lead to the collection of fines and even criminal charges in cases when the responsible party isn’t admitting fault. The PCL is one of just a handful in the country doing this work.