“…Used in conjunction with vadose zone monitoring networks [ Cullen et al , 1995; Bumb et al , 1998; Warrick et al , 1998], strategically configured groundwater monitoring wells facilitate early contaminant detection, thereby reducing aquifer cleanup costs [ Massman and Freeze , 1987]. The pattern of wells should account for several factors, including the uncertain location of a contaminant release, the direction(s) of groundwater flow, rock and soil characteristics, and proximity to receptors.…”