ARCHIVED REPORTS_PHASE II ENVIRONMENTAL SITE ASSESSMENT

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W GIlR, • Southwest, ]Inc. 5.4 Phase I Environmental Site Assessment The RECs identified by WGR in the Phase I ESA, as presented in the referenced September 14, 2007 report, are outlined in the following subsections. Aspects of the Phase II investigation designed to assess the specific RECs are identified as well. 5.4.1 Heavy Metals Since beginning operation as a scrap metal recycler in 1971, The Learner Company has handled and stored a wide variety of metal objects on the site. The scrap stockpiles rest directly on bare surficial soil. As the metallic materials are consolidated, sorted, cut,baled, shredded, loaded and stored, chipping and flaking of the metal occurs. hi many areas, metal scraps were observed to be buried in the soil. Because of the long history of operation, the relocation of the stockpiles over the years, and the lack of information regarding Learner's business practices during the 1970's and 1980's, it is not possible to eliminate any areas of the property as potentially contaminated zones. Probable heavy metal contamination to soil on the site was identified as a significant REC and was one of the primary issues addressed by this Phase II ESA. All of the soil samples recovered from the borings were analyzed for the 17 California Regulated Metals (CAM17 metals). Borings B-3 through B-6 and B-13 through B-18 were located in areas where • processing and/or stockpiling of metals has reportedly occurred in the past or was observed during the Phase I. 5.4.2 Storm Water Management Practices The Learner Company has in the past directed storm water into catch basins and depressions located in numerous areas across the site. The water has been allowed to percolate into the soil and to evaporate, potentially concentrating any contaminants contained in the storm water into the underlying soil. Because of the size and number of uncovered stockpiles and the predominance of oil, grease and other unidentified residues on much of the scrap metal, it is likely that a significant portion of storm water runoff on site has contained contaminants. This contaminated storm water is likely to have migrated into and through the underlying soil, eventually encountering groundwater. The past practice of containing storm water in onsite depressions and catch basins was thus identified as an REC, and several of these former low areas were targeted in this Phase II ESA. Specifically,borings B-1,B-2, B-5, B-11, B-12 and B- 18 were drilled in areas that had been mapped as depressions on Leamer stormwater drainage plans reviewed during the Phase I investigation. • 704. PRI.05 7 July 21, 2008