ARCHIVED REPORTS_XR0006951 - Laserfiche WebLink

Home Browse Search

KEI-P88-1013 December 15, 1988 Page 3 Based on the analytical results, the sampled stockpiles were 1 segregated into those with non-detectable levels of contamination and those with detected contaminants. Soil having non-detectable contamination was immediately available as backfill . Aeration ' permits were obtained for soil having detectable contamination, and aeration was conducted in accordance with the San Joaquin Air Pollution Control District guidelines, dated October 16, 1986. Following aeration, previously contaminated soil was resampled before making it available as backfill. Between the maximum excavation depth of 53 feet to approximately four feet below grade, clean imported soil and soil with non- detectable levels of contamination were returned to the pit and compacted. Between four feet depth and grade aerated soil having less than 10 ppm TPH was returned to the excavation and compacted. During the soil remediation program, approximately 2 , 000 cubic yards of soil were moved to a temporary storage area several blocks from the site. Constant track was kept as to which piles of soil were clean and which were contaminated. The relocated soil having detectable contamination was that material represented by composites Comp Al, A2 , B2 , E4 , X, Y, 1, 3 , 8 , 9 , 11 , and 13-18 inclusive (TPH level ranging from 1. 3 to 26 ppm) . This soil was aerated on-site prior to its relocation off-site ' for storage. Nineteen composite samples (labeled R-1 through R-19) were taken from this soil as it was returned to the site . The laboratory analyses indicated non-detectable contaminated TPH levels for all samples . In summary, 4 , 200 cubic yards of soil had non-detectable levels ' of contamination when first sampled, 1 , 800 cubic yards had detectable contamination when first excavated. Of the latter, approximately 200 cubic yards of soil were hauled to a Class I facility due to high levels of contamination. ANALYTICAL RESULTS All pit and stockpile samples were analyzed by Mobile Chem Lab, San Carlos, California, and were accompanied by properly executed Chain of Custody forms . All soil samples were analyzed for TPH using EPA method 5020 in con3unction with modified 8015, and benzene, toluene, xylenes and ethylbenzene (BTX&E) using EPA method 8020 . In addition, 25 pit samples and 32 composite stockpile samples were analyzed for EPA 8010 constituents .