FIELD DOCUMENTS_FILE 1 - Laserfiche WebLink

Home Browse Search

Michelle Price, City of Stockton September 18, 2013 Application to Discharge Extracted Groundwater to the Sanitary Sewer Barnes Trucking, Stockton, CA Page 2 SYSTEM DESCRIPTION The DPE system consists of a 20-hp liquid ring pump/blower, a 100-gallon knockout tank, a 2-hp transfer pump, and a 300 cfin thermal/catalytic oxidizer. Soil vapors and groundwater from the subsurface will be extracted by applying high vacuum on extraction wells using the liquid ring pump/blower. The air-water composition in the extracted stream will be separated in the knockout tank of the DPE unit. The separated groundwater in the knockout tank will be routed to two 1 ,000-1b carbon vessels, in series, using the 2-hp transfer pump in-built on the DPE system. The treated water will be routed to a 3,000 gallon holding tank for storage to allow for testing prior to discharging the treated water to the sewer clean out. The location of the sewer cleanout is shown on Figure 2 . Manufacturer' s specifications for the remediation equipment are included in Appendix B . EXTRACTION AND DISCHARGE RATES During this DPE test, based on system specifications and proposed mass removal event duration, Stratus estimates less than 120,000 gallons of groundwater will be extracted, treated and discharged. Actual gallons to be discharged are dependent on the contaminant mass extraction rate obtained during the duration of the pilot test event. Extraction wells used will be based on those located in the region of the highest levels of contaminants beneath the site (average extraction rate over the 30-day test duration is anticipated to be less than 5 gallons per minute [gpm] based on results from the previous 5-day DPE pilot test) . Stratus proposes to use two 1 ,000-pound carbon units, in series, to treat the extracted groundwater. Based on current concentrations of the petroleum hydrocarbons in the groundwater (Appendix C) and the rate of carbon usage that we have observed at various carbon based groundwater treatment systems that we oversee, Stratus believes that two 1 ,000 lb carbon vessels are adequate to treat the estimated 120,000 gallons of water. To quantify the carbon utilization rate, Stratus proposes to collect three water samples, upon start up and on a weekly basis during the event, including an influent water sample, a water sample after the first carbon vessel (midfluent), and an effluent water sample (after the second carbon vessel) . A water meter will be installed to record total flow and the operational flowrate. SAMPLING AND REPORTING PROTOCOL The treatment system will be monitored once upon start-up, and on a weekly basis throughout the duration of the test. Prior to start-up, performance evaluation sample ports will be installed prior to the primary carbon vessel (influent), between the primary and secondary vessels (midfluent), and after the secondary vessel (effluent) . Upon start- up, Stratus proposes to collect the first set of influent, midfluent, and effluent samples after treating approximately 508 gallons of extracted groundwater (approximate volume K9aames Trucking\Correspondmce\names Wastewater discharge pemri[ app Sept 2013.doc STRATUS