OCCURRENCE AND TRANSPORT OF PHARMACEUTICALS IN GROUND WATER OF SUFFOLK COUNTY, NEW YORK

Pharmaceuticals have been shown to infiltrate ground water systems in areas susceptible to wastewater contamination. Here, we present and compare data from two studies, conducted by Stony Brook University and the U.S. Geological Survey regarding pharmaceutical occurrence in susceptible ground water wells of Suffolk County, NY. Both studies targeted wells which were proximate to permitted wastewater treatment facilities discharging to ground water, although the Stony Brook wells were generally shallower (68 +/- 31 ft) and closer (0.25 +/- 0.23 mi) than the USGS wells (250 +/- 132 ft and 0.73 +/- 0.83 mi) to the point source. Both methods employed solid phase extraction followed by LC-MS and targeted similar suites of compounds. Pharmaceuticals were detected in both studies, and the range of detected concentrations was generally 1-200ng/L. Acetaminophen, caffeine, carbamazepine, nicotine, paraxanthine and sulfamethoxazole were detected in >50% of samples in the shallower wells, whereas only carbamazepine and sulfamethoxazole were detected in >5% of samples from the deeper wells. These ubiquities are consistent with other published frequencies of detection for pharmaceuticals in susceptible waters and suggest that these more frequently detected compounds are more persistent in ground water. The relative mobilities of pharmaceuticals in ground water were assessed by regarding the distributions of compounds, on three different occasions, in the well field of an adult assisted living care facility with an on-site wastewater treatment plant which discharges to ground water. These distributions, combined with laboratory sorption experiments, suggest that caffeine, carbamazepine, nicotine, paraxanthine and sulfamethoxazole have the potential for greatest transport in the subsurface. Other removal processes like microbial degradation were not investigated.