Use of on-site chemical analyses in the identification of groundwater contamination sources affecting the Rockaway Borough well field

Field chemical analyses were applied to an investigation of the Rockaway Borough well field, located in northwestern New Jersey, USA, and the designated sole-source glacial aquifer supplying the well field. The aquifer and the Borough water supply were found to be contaminated with up to 680 μg/L of tetrachlorethylene (PCE) and 172 μ/L of trichlorethylene (TCE) in 1980. The sources of the contaminants had not been identified in 1982 when the well field was placed on the United States Environmental Protection Agency National Priorities List of uncontrolled hazardous waste sites. A limited site investigation was conducted using on-site chemical analyses of groundwater samples and soil sample headspace gases. The investigation identified optimal monitoring well locations, provided cost-effective time series sampling data, and identified the locations of three potential contaminant sources.