Environmental Health - Toxic Substances Hydrology Program
Toxic chemicals such as chlorinated solvents in fractured rock aquifers pose a serious threat to the Nation's ground-water resources. Many industrial centers in America are located in the piedmont physiographic region where fractured rock aquifers are common. Improper disposal methods, leaking tanks and pipes, and chemical spills have contaminated fractured rock aquifers in and around many industrial centers. The restoration and protection of ground-water quality depend on knowledge of the physical, chemical, and microbiological processes that affect the fate of these toxic chemicals in fractured rock aquifers. The intent of this investigation is to help develop the knowledge needed to create practical and cost-effective methods to clean up and protect ground-water resources in fractured rock aquifers.
The Naval Air Warfare Center (NAWC) Research Site, West Trenton, New Jersey, is located 4 miles north of Trenton, New Jersey. The fractured bedrock at the site has been contaminated with trichloroethylene (TCE)--a chlorinated solvent. The plume of TCE was caused by leakage of TCE from aboveground service lines and storage tanks. The TCE was used as a heat transfer agent during jet engine tests. An estimated 100,000 gallons of TCE was lost through leakage and spills at the site. Dense nonaqueous phase liquids (DNAPL) have been identified at the site, and have flowed vertically downward and in the down-dip direction of the fractured sedimentary rocks. The aqueous phase plume of dissolved TCE has flowed along the strike and the up-dip directions of the sedimentary rocks. There is evidence of natural attenuation of TCE, probably and at least in part due to the presence of a jet-fuel oil spill that overlaps part of the plume.