Comparison of No-Purge and Pumped Sampling Methods for Monitoring Concentrations of Ordnance-Related Compounds in Groundwater, Camp Edwards, Massachusetts Military Reservation, Cape Cod, Massachusetts, 2009-2010.

摘要

Field tests were conducted near the Impact Area at Camp Edwards on the Massachusetts Military Reservation, Cape Cod, Massachusetts, to determine the utility of no-purge groundwater sampling for monitoring concentrations of ordnance-related explosive compounds and perchlorate in the sand and gravel aquifer. The no-purge methods included (1) a diffusion sampler constructed of rigid porous polyethylene, (2) a diffusion sampler constructed of regenerated-cellulose membrane, and (3)a tubular grab sampler (bailer) constructed of polyethylene film. In samples from 36 monitoring wells, concentrations of perchlorate (ClO4- ), hexahydro-1,3,5- trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro- 1,3,5,7-tetrazocine (HMX), the major contaminants of concern in the Impact Area, in the no-purge samples werecompared to concentrations of these compounds in samples collected by low-flow pumped sampling with dedicated bladder pumps. The monitoring wells are constructed of 2- and 2.5-inch-diameter polyvinyl chloride pipe and have approximately 5- to 10-foot-long slotted screens. The no-purge samplers were left in place for 13-64 days to ensure that ambient groundwater flow had flushed the well screen and concentrations in the screen represented waterin the adjacent formation.