FIELD DOCUMENTS 2002 - 2013 - Laserfiche WebLink

Home Browse Search

Site Background Information: Cherokee Truck Stop AGE-NC Project No. 97-0312 Page 3 of 6 PREVIOUS SITE ACTIONS - FORMER SURFACE IMPOUNDMENT Investigation of the former surface impoundment began in 1987 in response to a directive from the Central Valley Regional Water Quality Control Board (CVRWQCB) dated 29 December 1986 to characterize the area(CVRWQCB, 1986). The first phase of investigation included soil borings,sampling,and analysis and was performed by J.P. Services(JP)of Benicia,California. In JP's report dated 12 June 1987,concentrations of Total Petroleum Hydrocarbons as diesel (TPH-d) were found up to 38,000 milligrams per kilogram (mg/Kg) or parts per million (JP, 1987c). Two samples reported chlorinated solvents at concentrations up to 0.44 mg/Kg. Samples were analyzed for seventeen California Assessment Metals (CAM 17); none were reported above Total Threshold Limit Concentrations (TTLC). The CVRWQCB was present during the investigation and collected split samples. The CVRWQCB results reported slightly higher concentrations of metals than those reported by J.P. Services. Based on these results,JP performed a second phase of drilling in 15 July 1987 and submitted soil samples for total and soluble metals(data reported in Canonie, 1987b). Two soil samples reported soluble lead at concentrations of 27 and 28 milligrams per Liter(mg/L), above the Soluble Limit Threshold Concentrations (STLC) for lead of 5.0 mg/L. Based on these soluble lead results, the CVRWQCB determined that the surface impoundment contained hazardous waste and was therefore subject to the provisions of the Toxic Pits Cleanup Act(TPCA). In 1989, Kleinfelder and Associates (Kleinfelder) was retained to excavate a large portion of the impoundment and the surrounding area in an attempt to assess the vertical and lateral extent of hydrocarbons and lead in the soil(Kleinfelder, 1989b).Approximately 2,500 yards of material were removed and stockpiled on site before field activities ceased.Kleinfelder collected soil samples from seven locations within the area of excavation. Soil from three different depths at each location was analyzed for TPH and lead. Four samples exceeded STLC values for lead. During the 1989 excavation activities,the CVRWQCB obtained one soil and one sludge sample and analyzed them for metals and TPH. The analytical results for these samples are documented in a memorandum dated August 30, 1989 by the CVRWQCB which stated that the sludge contained zinc at concentrations exceeding TTLC values. ESE was retained by Delta Truck,Inc.in April 1990 to further characterize the former impoundment and the previously excavated stockpiled soil. ESE sampled the stockpile and then performed some additional excavation work in the former impoundment in May and June of 1990 (ESE, 1990b). In August of 1990, ESE drilled nine soil borings around the excavation to assess the vertical and Advanced GeoEnviron mental,Inc.