ARCHIVED REPORTS_PHASE II ENVIRONMENTAL SITE ASSESSMENT

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W1GIK • Sou[tlh[wwest, ffine. 5.4.3 Leakage from USTs and ASTs Following removal of the diesel and gasoline USTs from the site in 1996,hydrocarbon-impacted soil and groundwater were identified in the UST area. Soil from the UST excavation was stockpiled on site, mixed several times to enhance bioremediation, and returned to the excavation. A subsequent subsurface investigation indicated significant contamination was still present in the pea gravel at the bottom of the former excavation and in the surrounding soil and groundwater (Clayton Group Services, 2002). Three monitoring wells were installed and monitored for a period of one year. Diesel was identified as the major contaminant, although gasoline-range hydrocarbons and MTBE were also detected in soil and groundwater. Although the UST case was closed by the regulatory agencies, the documented historical petroleum hydrocarbon impact to soil and groundwater in the vicinity of the former USTs identified this area as an REC. The USTs were replaced by a stationary 3,000-gallon divided diesel and unleaded gasoline AST. The AST is not equipped with overfill protection, and staining was noted on the AST and the concrete surface below. A portable 350-gallon diesel AST is stored in this area as well. It is an older single-walled tank that was noted to be rusty, dented, stained and in generally poor • condition with no overfill protection. The two ASTs are surrounded by a rock and soil berm for secondary containment. The current condition of the ASTs and their lack of overfill protection qualified as an REC. Boring B-9 targeted the current AST area and was located outside of the anticipated pea gravel backfill of the former UST excavation,but as near as possible to it. 5.4.4 PCB Contamination and Concerns A PCB release to the ground occurred in the area of the former shredder when a switch gear was ruptured during demolition of the shredder and adjacent mill in August 2007. At the time the Phase I ESA was prepared, WGR had been informed that oil containing PCBs was spilled and the Office of Emergency Services had been notified. Much of the liquid released appeared to have flowed into a shallow pit east of the old shredder, however, the pit was covered and only a small portion was visible at the time of the Phase I site visit by WGR. WGR was informed by representatives of Learner and Miller Brooks during the Phase II ESA field work that assessment and remediation of the August 2007 PCB spill is ongoing and is being conducted by Miller Brooks. In addition to the known PCB spill, additional PCB contamination on the site was determined to be possible. Learner has reported that electric capacitors and light ballasts are sometimes • discovered in the stockpiles. It is likely these items are discovered as they are moved or 704. PRI.05 8 July 21, 2008