Laserfiche WebLink
20 BACKGROUND <br /> The former AFPC facility is located ,lust outside the city limits of Stockton, California <br /> AFDC operated a wood manufacturing plant at the site between 1921 and 1987 The Site consists <br /> of several structures which include storage sheds for lumber, various wood manufacturing equipment <br /> and offices A large maintenance shop was located at the southern end of the facility until its <br /> demolition in 1990 The maintenance shop was used for storage of plumbing and electrical parts <br /> required for building maintenance Fork lifts and motor vehicles were also serviced and refueled <br /> at the maintenance shop, thus requiring fuel storage and pump islands nearby <br /> According to old site plans three USTs were located in the vicinity of the maintenance shop <br /> A 10,000 gallon UST and pump island were located on the western site of the building A 500- <br /> gallon UST, used for the storage of waste lubricating oil and spent solvent, was located on the <br /> eastern side of the maintenance shop At one time a 325-gallon underground gasoline or diesel tank <br /> also existed on the eastern side of the building according to plant personnel, but was evidently <br /> removed, although no records of the removal were kept The age of these tanks is not known, <br /> although, according to plant personnel, the tanks were at least 30 years old <br /> The 10,000-gallon diesel tank and 500-gallon waste oil tank, were removed under the <br /> supervision of PHS-EHD in 1988 A supplemental soil and groundwater investigation, feasibility <br /> study, and remedial action plan was completed in 1988 by Dames & Moore (Dames & Moore, <br /> 1988) After review of the feasibility study, the RWQCB agreed to the concept of limited soil <br /> excavation and on-site treatment, but requested a work plan for soil remediation and installation of <br /> additional monitoring wells The correspondence from the RWQCB is attached as Appendix C <br /> Following soil excavation, treatment, and disposal, Dames & Moore submitted a Site <br /> Remediation Report to the California Regional Water Quality Control Board (RWQCB) and PHS- <br /> EHD (Dames & Moore, May 1992) This report also included the results from the first of four <br /> quarterly groundwater monitoring rounds conducted in four newly installed monitoring wells The <br /> replacement monitoring wells were needed as the depth to groundwater had fallen from <br /> approximately 35 feet bgs in 1987 to approximately 68 feet bgs in 1991 None of the groundwater <br /> samples collected from monitoring wells on the Site from 1987 to 1994 have reported detections of <br /> any hydrocarbon constituents <br /> After review of the Site Remediation Report, the RWQCB commented that if groundwater <br /> returns to its former level, only nine feet would separate soils with residual concentrations of total <br /> petroleum hydrocarbons as diesel (TPH/D) from groundwater As a result, the RWQCB indicated <br /> SAC127 to 2 <br /> DAMES &MOORE <br />