SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

1 gauges, flow meters, instrumentation and controls; and a six-foot high, slatted chain link fence (Precision or approved equal) to preclude public access. The vapor extraction blower shall be capable of extracting vapors at a rate of 215 cfm at 70 inches H2O. A process and instrumentation diagram for the VES is shown on the attached Plans. Section 10.4 Air Sparge System The proposed groundwater AS:isystem shall utilizethree new air sparge wells and a compressor to address the hydrocarbon impacted groundwater. The AS system shall be. operated at an injection pressure of approximately 10 psi and an injection flow rate of ` approximately 3 to 5 cfm per well The AS system shall be operated using individual wells in sequence with on-line vapor extraction wells to control migration of the groundwater plume. The wells shall be constructed of 2-inch schedule 40 PVC and shall be screened from approximately 37 to 40 feet bgs. A map showing the radius of influence is included on the attached Plans. Similar to the VES, the actual radius of influence for each sparge well may vary and the effective radius of influence shall be evaluated following long-term operation of the AS system. The AS system shall include a compressor; associated piping, control valves, pressure gauges, flow meters, instrumenta#ion and controls; and a remediation enclosure shared with the VES. The compressor shall be capable of creating a maximum of 20 pounds per square inch pressure and a maximum airflow rate of 55 standard cubic feet per minute. A process and instrumentation diagram for the VES is shown in the attached Plans. Section 10.5 Remediation System Layout Components of the vapor extraction and air sparge system would be located in a remediation enclosure enclosed by a six-foot high, slatted chain link fence (Precision or approved equal) on the west side of the site. A network of subsurface piping shall be used to conveyoff as from the extraction wells to h g the remediation enclosure. The trenching system layout is shown in the attached Plans. The same trenches shall be used for the air sparge system. Piping shall be used to convey air to the sparge wells for injection to the subsurface. Piping shall be installed at a maximum depth of two feet as shown on the attached Plans. A two-foot by ,two-foot well vault shall be installed over each vapor extraction and air sparge well. A!ball valve shall be installed at each well head to control the airflow in or out of the well. In'addition, a sampling port shall be installed at each vapor extraction well for monitoring purposes. .i Equipment operation shall require the installation of an electrical power source and meter base. Ms. Sharla Hardy of the City of Stockton Public Works Department at (209) 937- 8374 shall be responsible for contacting PG&E to bring the power source to the remediation enclosure. A NEMAA, UL Listed Control Panel or equivalent shall be located at the enclosure. Section 10.6 Equipment Equipment to be used with the Vapor Extraction and Air Sparge Systems includes, but is not limited to: Compressor, 55 cfm, 20psi; Motor, 7.5 hp, 1725 rpm; Blower 215 cfm, 70° H2O; Liquid separator, 19 gal, 2" NPT; Check valves; Pressure gauges, 2", 0-30 psi; Pressure relief valves; Vacuum gauges; Temperature gauges; _Level Switches; Sampling Ports, Air Flow Meters;: PVC piping, 2", sch 40; Ball valves; and a six foot high slatted chain link fence. SP8