Skip to main content
U.S. flag

An official website of the United States government

Natural Attenuation in Source Zone and Groundwater Plume - Bemidji Crude Oil Spill

December 31, 2019

A long-term study of a 40-year-old crude oil spill provides insights about petroleum hydrocarbon natural attenuation processes and rates. In the source zone, fermentation coupled to methanogenesis is the dominant natural source zone depletion (NSZD) process, and most of the carbon mass exits the surface as CO2 efflux. Monitored natural attenuation (MNA) of the groundwater plume shows that benzene degradation is coupled to iron reduction and that the benzene plume is stable. A plume of hydrocarbon oxidation products measured as nonvolatile dissolved organic carbon (NVDOC) expanded ~20 m in 20 years. Most of the NVDOC is biodegraded by 200 m from the source, but optical data suggest there are components that persists for 300 m. Biological effects screening indicates decreasing biological effects with distance from the source.

Citation Information

Publication Year 2019
Title Natural Attenuation in Source Zone and Groundwater Plume - Bemidji Crude Oil Spill
Authors Barbara A. Bekins
Publication Type Book Chapter
Publication Subtype Book Chapter
Index ID 70237844
Record Source USGS Publications Warehouse
USGS Organization WMA - Earth System Processes Division

Related Content