Laserfiche WebLink
EPRV <br /> Stockton Scavenger Association Facility <br />' November, 1997 <br /> Page 4 <br />' All three excavations were backfilled with Class li base rock Prior to and during backfilling of the <br /> north pit, piping for a vapor extraction/reinjection sod remediation system was installed To remove <br /> the trace concentrations of hydrocarbons remaining in the walls and floor of the north pit, MARK <br /> operated an in situ vapor extractionfinjection system for a period of eight weeks Hydrocarbon- <br /> laden air was extracted from the soil using a vacuum blower, was abated with two carbon <br /> canisters, and the compression-heated air was then reinjected into the subsurface The system <br /> t was turned off when influent hydrocarbon concentrations, measured with a photoionization detector <br /> (PID), reached a level of 1 part per million (ppm) by volume <br /> 3 2 Groundwater Remediation <br /> On July 16, 1994, MARK implemented groundwater remediation at the subject site using a pump <br /> and treat system in the well with highest petroleum hydrocarbon concentrations (MW-2) The <br />' pump and treat system consisted of a pneumatic pump in monitoring well MW-2, a dedicated air <br /> compressor, and two 175-pound granular activated carbon canisters Treated groundwater was <br /> discharged to the City of Stockton sanitary sewer under an appropriate permit The pump and treat <br /> system operated until December 1996 at approximate flow rates ranging from 1 to 4 gallons per <br /> minute and removed a total of approximately 592,000 gallons of groundwater Operation of the <br /> groundwater pump and treat system is discussed further in Section 5 0 <br /> 1 <br /> 1 <br /> 1 <br />' 5027002 ART <br />