COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

e soil types encountered in the boring-were: silty clay from beneath the concrete to a -- — � depth of approximately 8.5 feet, silty sand from 8.5 feet to approximately 11.5 feet, silt from 11.5 feet to approximately 22.5 feet, sand from 22.5 feet to approximately 35.5 feet. The boring was completed at a depth of approximately 36 feet in a clay. A copy of a boring log legend and the boring log are attached. The soil samples for potential laboratory analysis were collected by drilling to immediately above the sampling interval. A modified California split-spoon sampler lined with three 6-inch stainless steel tubes was then driven into the undisturbed soil. Upon removal from the boring, the sampler was opened and the bottom tube removed. Upon removal, the bottom tube was immediately sealed with Teflon sheeting and plastic caps, labeled, logged on a chain-of-custody, and placed in an iced cooler. Upon completion of the boring and soil sampling, the boring was grouted through tremie pipe using a cement/bentonite grout. The grout was mixed at approximately 8.5 gallons of potable water per 94-pound sack of Portland Type I-II cement with 3 percent (by weight) bentonite. z j Analytical Results Two soil samples were designated by SJCEHD for quantitative analysis. Soil samples from 20 and 35 feet below the ground surface were submitted to Superior Precision Analytical Laboratories, Inc. (Superior) in Martinez, California under chain-of-custody control. Superior is certified by the State of California Department of Toxic Substances Control (DTSC) for the requested analyses. Both samples were analyzed for: ► Purgeable total petroleum hydrocarbons ('IPH) as gasoline by EPA Method 8015M/5030 ► Benzene, toluene, ethylbenzene and xylenes (BTEX) by EPA Method 8020 ► Ethylene dibromide (EDB) by EPA Method 8011 ► Total lead by EPA Method 6010 The samples were analyzed on a standard laboratory turnaround. Analytical results were sent directly to SJCEHD by the laboratory. A copy of the laboratory data sheets and chain-of-custody form are attached. Purgeable TPH, BTEX and EDB concentrations were not detected above laboratory reporting limits (1, 0.003, and 0.001 mg/kg respectively). Total lead was detected at the laboratory reporting limit of 5 mg/kg in the 20-foot sample (#74228), but was not detected above laboratory reporting limit in the 35-foot sample (#74231). Conclusions and Recommendations Based on the analytical results of the verification soil samples and the field observations of Kleinfelder's on-site representative, Kleinfelder recommends no further assessment or remediation. FR10-22(1993) Page 2 of 3 24-220222-A00 Copyright 1993 Kteinfetder, Inc.