ARCHIVED REPORTS_XR0013109 - Laserfiche WebLink

Home Browse Search

V �. Excavation Remediation Report Advanced Environmental Concepts,Inc. V The current state maximum contaminant levels (MCLs) for drinking water set by the California Department of Health Services, Title 22 are as follows: Benzene.................................. 1 pg/L Toluene................................... 2000 pg/L Ethylbenzene......................... 680 pg/L Total Xylenes......................... 1750 pg/L FINDINGS • B he results of laboratory analyses of soil sampies collected during the assessment phase, the vertical extent of gasoline contamination within soil was delineated between 4 and 14 feet BGL. Groundwater sample analyses indicated the presence of concentrations as high as 28,900 parts per billion gasoline and 1,030 parts per billion benzene prior to the remedial excavation and backfilling procedures. Groundwater sample analyses performed after the completion of the remedial action indicated no detectable concentrations of gasoline range petroleum hydrocarbons and trace to non detectable volatile organic compounds. • Petroleum hydrocarbon-impacted soil was excavated to a total depth of 13 to 20 feet BGL throughout the former UST emplacement area. Clean borrow fill material mined from an adjacent parcel was used to backfill the excavation, which was first lined with a minimum of one foot drain rock. • Ground water beneath the site was encountered between 12 and 15 feet BGL within the three assessment borings completed as monitoring wells. No gasoline-range petroleum hydrocarbons, and trace to non detectable volatile organic compounds were detected within samples collected and analyzed from these wells during September 1998, and November 1998. 7.0 RECOMMENDATIONS Advanced Environmental Concepts,Inc.recommends no additional phases of soil or groundwater sampling be performed. AEC recommends that no additional actions be required and respectfully requests final closure of this case. Q001 r. 8.0 STATEMENT OF LIMITATIONS This work has been performed in accordance with generally-accepted environmental science and geologic practices. Soil samples were obtained on a discrete,finite grid, hence they are not meant to be misconstrued as representative of unsampled subsurface areas. Conclusions and recommendations are based upon information collected and compiled during this investigation and data provided by the client. No other warranty, expressed or implied, is given. V Project: AEC 96C-1707 13 V •ENVIRONMENTAL CONCEPTS WITH DESIGN IN MIND - 4400 ASHE ROAD.#206 • BAKERSFIELD.CA 93313 8051831-1646 FAX 8051831-1771 V