Movement and fate of chlorinated solvents in ground water; research activities at Picatinny Arsenal, New Jersey

Abstract

The U.S. Geological Survey, through its Toxic Waste-GroundWater Contamination Program, is undertaking an interdisciplinary research study of groundwater contamination by chlorinated solvents and associated contaminants. The purpose of the study is to gain a better understanding of the chemical, physical, and biological processes that affect the movement and fate of these contaminants in ground water. The study is being conducted at Picatinny Arsenal, New Jersey, where metal-plating and metaletching wastes have contaminated part of the glacial stratified-drift aquifers. This paper describes major areas of research at the site, including: (1) distribution and movement of chlorinated solvents in ground water, (2) behavior of chlorinated solvents in the unsaturated zone, (3) geochemistry of the contaminated ground water, and (4) microbial transformations of chlorinated solvents. This paper also describes objectives and plans of action for these areas of research.

Quantification of Natural Vapor Fluxes of Trichloroethene in the Unsaturated Zone at Picatinny Arsenal, New Jersey

“…The primary solvent used for degreasing was TCE. TCE concentrations as high as 44 mg/L have been measured in water samples collected from the aquifer using purge-and-trap gas chromatography/mass spectrometry (28). These disposal practices resulted in a contaminant plume in the unconfined aquifer extending about 500 m from Building 24 to Green Pond Brook.…”

“…The shaded area in Figure 1 identifies the part of the aquifer with aqueous TCE concentrations greater than 10 µg/L and is based on a synoptic sampling of 38 wells screened in the unconfined aquifer during October and November 1991 (26,27). TCE concentrations as high as 44 mg/L have been measured in water samples collected from the aquifer using purge-and-trap gas chromatography/mass spectrometry (28). Because Green Pond Brook (Figure 1) acts as the discharge point for the water-table aquifer in the valley, no TCE has been detected in groundwater on the southeast side of Green Pond Brook.…”

Effect of soil moisture on the sorption of trichloroethene vapor to vadose-zone soil at Picatinny Arsenal, New Jersey

“…The major component of the organic contamination in the groundwater is trichloroethene (TCE); the approximate areal distribution of the TCE is shown by the isoconcentration lines in Figure 1, which are based on an extensive groundwater sampling program conducted in October-November 1987. Details of the groundwater contamination, as well as additional information on site hydrology, lithology, and source contamination history are reported elsewhere (1)(2)(3)(4)(5)(6). This study investigates the potential effect of soil-moisture content on the sorption of TCE vapor by vadose-zone soil above the groundwater solute plume at Picatinny Arsenal in order to gain a better understanding of the system parameters mediating the dynamics of vapor movement in the vadose zone.…”