Environmental Health - Toxic Substances Hydrology Program
Community waters are treated and disposed either to surface waters or ground water. These wastewaters include water from both domestic and industrial/commercial uses. Domestic wastewater includes chemicals that are typically used in and discharged from the household. The wastewaters from industrial, commercial, institutional, and similar facilities can have a varied chemical character. Even after treatment, wastewater discharges can contain a wide range of organic chemicals, and inorganic chemicals including metals and nutrients. The complex mixture of contaminants in wastewater effluent provides an opportunity to study a myriad of chemical and microbial reactions in the subsurface.
The Toxics Program is investigating a wastewater plume in a shallow sand and gravel aquifer near Cape Cod, Massachusetts. The ground-water plume is about 2.5 miles long, and contains chlorinated hydrocarbons, detergents, metals, nitrate, and microbes. Detailed sampling of the plume and large-scale tracer experiments have provided an opportunity to demonstrate a fundamental approach for characterizing the heterogeneous nature of subsurface contaminant plumes. The data also are being used to develop models that enable scientists to design monitoring strategies, to predict how contaminants spread in the subsurface and to estimate how quickly contaminants in sewage degrade to less toxic compounds. These methods are being used at other contaminated sites nationwide.