Disposal of secondary sewage effluent by rapid infiltration has produced a plume of contaminated groundwater over 3500 m long near Falmouth, MA. Approximately 50 volatile organic compounds were detected and identified in the plume, at concentrations ranging from 10 ng/L to 500 ??g/L, by closed-loop stripping and purge- and-trap in conjuction with gas chromatography-mass spectrometry. The dominant contaminants were di-, tri- and tetrachloroethene, o- and p-dichlorobenzene, C1 to C6 alkylbenzenes, 2,6-di-tert-butylbenzoquinone, and several isomers of p-nonylphenol. The chloroethenes and chlorobenzenes had the same general distribution as chloride and boron and appear to be transported with little retardation. Less soluble compounds, such as nonylphenol and di-tert-butylbenzoquinone, appear to be retarded during subsurface transport by sorption processes. Although biodegradation of labile organic compounds occurs near the infiltration beds, many trace compounds, including chlorinated benzenes, alkylbenzenes, and aliphatic hydrocarbons, have persisted for more than 30 years in the aquifer.
Additional Publication Details
Long-Term Fate of Organic Micropollutants in Sewage-Contaminated Groundwater