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Michelle Price,City of Stockton May 1,2014 Application to Discharge Extracted Groundwater to the Sanitary Sewer Quick-N-Save#2 Stockton,CA Page 2 SYSTEM DESCRIPTION The GWP&T system consists of submersible pumps installed within each extraction well (EW-1 and EW-2) with the remediation piping routed from the extraction wells via subgrade piping to the remediation compound that will contain a receiving tank, particulate filters, and three 1,000 pound granular activated carbon (GAC) vessels connected in series. After treatment, the groundwater will be discharged to the sanitary sewer. The treated groundwater will initially be routed to a 3,000 gallon holding tank, after the final GAC, for temporary storage to allow for approved sampling results prior to discharging the treated water to the sewer clean out. Once effluent samples are approved, the system will directly discharge the treated groundwater from the final GAC into the sanitary sewer. The location of the sewer cleanout is shown on Figure 2. Manufacturer's specifications for the remediation equipment are included in Appendix C. EXTRACTION AND DISCHARGE RATES During this GWP&T event, based on system specifications and proposed mass removal event duration, Stratus estimates approximately 3.6 million gallons of groundwater will be extracted, treated and discharged. Location of the proposed extraction wells are based on highest levels of contaminants beneath the site (average extraction rate over the event duration is anticipated to be between 3 to 4 gallons per minute [gpm], with a maximum average monthly flow of 5 gpm). Stratus proposes to use three 1,000-pound carbon units, in series, to treat the extracted groundwater. Based on current concentrations of the petroleum hydrocarbons in the groundwater (Appendix D) and the rate of carbon usage that we have observed at various carbon based groundwater treatment systems that we oversee, Stratus believes that three 1,000 lb carbon vessels are adequate to treat the estimated 3.6 million gallons of water. To quantify the carbon utilization rate, Stratus proposes to collect three water samples, upon start up and on a monthly basis during the event, including an influent water sample, a water sample after the first and second carbon vessels (two midfluent samples), and an effluent water sample (after the third 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 monthly basis throughout the duration of the remediation event. Prior to start-up, performance evaluation sample ports will be installed prior to the first carbon vessel (influent), between the first and second carbon vessels (midfluent), and after the third carbon vessel (effluent). Upon start-up, Stratus proposes to collect the first set of influent, midfluent, and effluent samples after treating approximately 1,000 gallons of extracted groundwater (approximate volume of water in a carbon vessel is 254 gallons). To obtain approval to discharge the treated groundwater, Stratus will sample the treated effluent groundwater K:\Quick N Save#2\Correspondence\QNS#2 Wastewater discharge permit app April 2014.doc STRATUS