Analysis of Mercury Species in New Jersey Ground water Using Inductively Coupled Plasma - Mass Spectrometry and Gas Chromatography

Water samples from 78 private potable wells in southern NJ were collected for mercury analysis in 19911992. The wells are located in Atlantic, Burlington, Camden, Cape Map and Ocean Counties. Total mercury concentrations varied from 1 ng/L to over 36 Fg/L. The dominant form in which mercury occurred in the wells sampled was inorganic, although monomethylmercury was present in some wells comprising up to 8% of the total mercury in one ground-water sample. Mercury analyses performed using the EPA Method 245.1 should be interpreted with caution. While this method is generally suited for analyzing waters having elevated mercury concentrations (total mercury levels above 2000 ng/L or 2 μg/L), it is less sensitive and even inadequate for characterizing background mercury levels. INTRODUCTION contamination was first discovered. The levels found In the late 1980's, private drinking water wells reported in the state. In fact, there are no reports in in Atlantic County, NJ were found to contain levels of the available literature showing similar levels of mercury above the 2 micrograms per liter (μg/L or mercury in ground water. parts per billion) maximum contaminant level (MCL) NJ Department of Environmental Protection set by US Environmental Protection Agency and Energy (NJDEPE) responded to the Atlantic (USEPA). As a result of these findings, the Atlantic County findings by launching an intensive sampling County Department of Health (ACDOH) instituted an campaign in cooperation with local health officials. aggressive county-wide sampling program to To date, water samples collected from NJDEPE and determine the magnitude and extent of this county health departments from more than 250 contamination. Results of their sampling showed potable domestic wells completed in the upper that mercury contamination is widely distributed Kirkwood-Cohansey aquifer system in the NJ Coastal throughout Atlantic County. Mercury levels as high as 40 μg/L have been observed by ACDOH since the by local health officials in this county are the highest