Polyaromatic Hydrocarbon Data for Oil Samples from the Bemidji Oil Spill Research Site, 1987-2020

The USGS is conducting a long-term study of a terrestrial crude oil spill that resulted from a ruptured pipeline in 1979. Samples of oil bailed from wells were analyzed for polyaromatic hydrocarbons by a commercial lab. A total of 32 samples were analyzed in three batches. A sample that serves as a surrogate for the original spilled oil was submitted with each batch. For each oil sample concentrations of a conservative compound can be compared to that found in the original spilled oil surrogate to obtain an estimate of the total oil mass that has been biodegraded.