The Portland District Army Corps of Engineers (Corps) conducted a Preliminary Assessment (PA) of the site 5/28/92. During a reconnaissance inspection, a concrete target butt, butt house, and a pistol range with a dirt impact berm were observed. The construction of the concrete target butt and butt house probably occurred soon after the government obtained the property in December 1946. The pistol range was likely constructed during the Vietnam era. While the former range was active, thousands of rounds of ammunition were fired into target-butt and impact-berm areas of the rifle and pistol range. Target-butt and impact-berm soils are likely permeated with bullet slugs and jacketing material. It is possible that other areas of the 34-acre parcel and the 198-acre 'firing fan' also have accumulations of bullet slugs and jacketing material. The current property owner has not noted any lead slugs in soil during recent construction activities (or at any other time).

EPA completed its PA in late 2004, having collected two surficiall soil samples in the "target fan" area and one surface soil sample in a background location. Both soil samples from the target fan area contained high levels of lead (4,180 and 6,870 parts per million, respectively, compared to a background level of 22.8 ppm).