ARCHIVED REPORTS_XR0003170 - Laserfiche WebLink

Home Browse Search

Uriah, Inc. was engaged by the City Thrift and Loan Association ' to conduct a limited environmental assessment of the sub3ect site during January and February of 1991 (Uriah, 1991a) . On the basis of data acquired during this assessment, additional work was authorized by the property owner and a workplan was ' submitted to DPHS/EHD. ' ASSESSMENT PROTOCOL On December 12 , 13 , and 16, 1991 , three ( 3 ) soil borings were drilled at the locations illustrated in Figure 2 . Each of the ' borings was advanced with a truck-mounted, drill rig equipped with 8"-outside diameter, continuous flight, hollow-stem augers operated by employees of Soil Exploration Services , Inc. ( SES) of Vacaville, CA. Drilling was performed under the direction of Michael Wopat, Ph.D. , a California Registered Geologist. ' Discrete soil samples were collected at five foot intervals (beginning at six [ 6 ] feet below ground surface [bgs ] ) .in a 2 inch inner-diameter split-spoon sampler fitted with clean brass tubes 1 . 9 inches in diameter by 6 . 0 inches in length. ' The sampler was driven 18" into undisturbed soil using a standard 30-inch drop of a 140-pound hammer. The borings were continuous- ly cored between 15 and 25 ft bgs, and were logged using the Unified Soil Classification System. Upon being retrieved from the sampler, the ends of the lowermost brass tube were covered with teflon sheeting, fitted with plastic caps, and sealed with duct tape. Each tube was then labeled and placed in a heavy- duty zip-lock plastic bag under ice pending transportation to McCampbell Analytical, Inc. of Pacheco, CA, a State-certified hazardous waste analytical laboratory. ' The samples were subsequently analyzed for Total Petroleum Hydrocarbons as Gasoline (TPH-G) , benzene, toluene, ethylbenzene, and total xylenes (BTEX) using EPA Methods 5030/8015-8020; Total Petroleum Hydrocarbons as Diesel (TPH-D) using EPA Methods 3550/ 8015; and Total Lead using EPA Method 7421 . The soil borings were each advanced to a depth of 60 feet, with the deepest soil samples acquired at 61 .0-61 . 5 feet bgs. Ground- water was encountered at slightly different depths within the three borings (at 60 feet, rising to 57 feet in EB-4; at 60. 5 feet, rising to 58. 5 feet in EB-5; and at 60. 3 feet, rising to 58 .5 feet in EB-6) . One grab water sample was taken from each boring with a clean, disposable polyethylene bailer. Each ' sample was promptly transferred into three 40-m1 Volatile Organic Analysis (VOA) vials acidified with sufficient HCl to reduce the pH to <2 . 0, one 500-m1 polyethylene sample bottle acidified with HNO3, and two 1 -liter amber glass sample bottles. Each sample container was fitted with a teflon-lined screw cap, 2.