Risk Assessment on Organic Contamination of Shallow Groundwater of an Oilfield in Northeast China

With the oil contaminated site of an oil field in northeast as the research area, based on the site geological and hydrogeological conditions, and by virtue of the methods of assessment on current situation of organic contamination and environmental impact assessment as well as leaching mobility assessment on organics, the internal and external risk assessments on organic contamination of shallow groundwater in the research area are conducted respectively. According to the results, about 30 kinds of organic components, including chlorinated hydrocarbons, mononuclear aromatics, heteroaromatic compound, polycyclic aromatic hydrocarbon and n-alkanes, are detected in the shallow groundwater in the research area. The current situation contamination of dichloromethane is the most serious, and all well points are of contamination at medium or above level. Compared with dichloromethane, contamination of trichloromethane and benzene is lighter, but several seriously contaminated well points occur in these two groups. The leaching mobility of dichloromethane, trichloromethane and benzene is extremely high, posing the greatest contamination risks against groundwater.