Simulation of solute transport of tetrachloroethylene in ground water of the glacial-drift aquifer at the Savage Municipal Well Superfund Site, Milford, New Hampshire, 1960-2000

Effects of a remedial system and its operation on volatile organic compound-contaminated ground water, Operable Unit 1, Savage Municipal Well Superfund Site, Milford, New Hampshire, 1998-2004

“…From 1983, when contamination was first detected by NHDES and USEPA, until 2004, ground-water quality of the primarily PCE plume was monitored. Prior to 1999, when the remedial system began operating, PCE concentrations in ground water at OU1 showed modest decreases from 1983 to 1999 (Harte, 2004) probably from a shrinkage in the DNAPL pool from the continuing dissolution of DNAPL into the ground water. After 1999, PCE concentrations decreased at double the rate of preremedial conditions (Harte, 2004).…”

“…A 50-percent reduction of recharge was attributed to the crown based on water-level responses to precipitation (water-level accretion method; Rasmussen and Andreason, 1959) after construction of the barrier wall in the fall of 1998. Simulations of ground-water flow and solute transport (Harte, 2004) of transient recharge events indicate that the reduc tion of recharge from the crown is likely less than 50 percent. Water-level rises in water years 2000-01, correlated to specific precipitation events during stable remedial operation peri ods (no variation in extraction or injection for several days), indicate that the crown reduces recharge by 15 to 45 percent (mean value of 30 percent) based on the water-level accre tion method.…”

“…A computed water budget of the net extraction of water inside the barrier indicated bedrock upflow was a large percentage (approximately 50 percent) of the source of water to IW-1 and IW-2 extraction wells (Harte, 2004). Monitor ing of continuous water levels in the overburden and bedrock wells showed that net extraction of overburden water from inside the barrier caused bedrock water levels to decrease (Harte, 2005).…”

“…Because of the high rate of ground-water flow in B95-9, with similar decreases at PW-8M, and PW-5D. Waterthe exterior area and high hydraulic conductivity, extraction Horizontal-head gradients in the bedrock between recharge periods (Harte, 2004).…”

“…Furthermore, solute transport of PCE was investigated and a transport model cali brated for the OU1 and OU2 areas (Harte, 2004).…”