COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

� � a STATE OF CALIFORNIA GEORGE DEUKMEJIAN,Governor CALIFORNIA REGIONAL WATER rlUALITY CONTROL BOARD— CENTRAL VALLEY REGION 3443 ROUTIER ROAD V SACRAMENTO,CA 95827 3098 - J iv I L MAR 2 6 ", 21 March 1990 ENVIRONMENTAL HEALTH PERMIT/SEL:RVICES Mr. Eric Sung C & L Tracy Group Partnership 21060 Rainbow Drive Cupertino, CA 95014 REVIEW OF PROBLEM ASSESSMENT REPORT FOR POTENTIAL SOIL AND GROUND WATER CONTAMINATION, C & L TRACY GROUP PARTNERSHIP, APN 235-15-22, TRACY, SAN JOAQUIN COUNTY Review of your Problem Assessment Report dated 15 August 1989 indicates that hydrocarbon contamination exists on the northwest part of your property. An investigation by Geo Resources in April 1989 found soil contamination from crude petroleum at fifteen feet below the surface. The Geo Resources soil borings inside the soil contamination area contain the following: Toluene- 7.0 ppm; Ethylbenzene- 24 ppm; Xylene- 12 ppm; Total Petroleum Hydrocarbons (TPH) as Gasoline-790 ppm; TPH as Diesel- 1300 ppm; and Petroleum Oil- 8900 ppm. The Report did not indicate whether or not the source contain leaded or unleaded gasoline. In August 1989, WaterWorks completed a second investigation to determine the lateral and vertical extent of soil contamination and the impacts on water quality. The second Problem Assessment Report dated 15 August 1989 indicated approximately 1400 cubic yards of crude petroleum contaminated soils is confined to an area approximately fifteen feet below the surface. Three of WaterWorks soil borings outside of the area of soil contamination were converted to ground water monitoring wells. Total Petroleum Hydrocarbons (TPH) as diesel were found at a concentration of 1 .39 parts per billion (ppb) in MW1 located northwest of the soil contamination, the other two wells showed levels less than 0.02 ppb. The water table is approximately fifteen feet below the surface and data indicates that the ground water flow is to the northwest (WaterWork did not determine the hydraulic gradient) . The Report concluded that the soil contamination was located at the water table and that offsite migration of the contaminated ground water had not occurred. The Report concluded that the source of the soil and ground water contamination was crude oil leaking from the old onsite pipelines that were removed over 15 years ago. Finally, the report stated the residual soil contamination left after the pipeline removal has had a negligible impact on the shallow ground water. Therefore, WaterWorks recommends verification sampling of the monitoring wells followed by site closure if results indicate that ground water contamination has not migrated offsite.