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18 October 2013 <br />AGE Project No. 99-0559 <br />Page 2 of 5 <br />pump inlet to allow the well to recharge, after which the pump reactivates. Extraction well <br />pumps become active when sufficient groundwater is present in these extraction wells; <br />presenting some non-operational time required to recharge groundwater into the extraction <br />wells. <br />The groundwater treatment system operates on a batch basis: approximately 80-90 gallons <br />of extracted groundwater is treated and discharged, with a daily total permitted up to <br />7,200 gallons. Total flow (totalizer) was recorded utilizing the Invensys PMM series <br />one-inch inline flow meter/totalizer. The treated water (effluent) is discharged, under permit, <br />to the City of Stockton Municipal Wastewater Facility Plant. <br />The flow meters and LEL measuring flow and lower explosive limits were inspected and <br />re-calibrated (monthly). The LEL and flow meter were calibrated in the third quarter by <br />Cooper Controls (third party agent) in August 2013 (Appendix D). A minimum of four <br />thousand pounds of granular activated carbon, were used to treat the groundwater. <br />2.2. MONTHLY MONITORING PROCEDURES <br />Monthly monitoring and sampling of influent groundwater extracted from wells EW-1, EW-2 <br />and EW-4 was performed on 26 July, 29 August and 25 September 2013. A sample of the <br />wastewater from the air-stripper was sampled during each event to monitor the efficiency <br />of the extraction system. <br />Monitoring and sampling was performed to quantify the mass of contamination removed <br />from active extraction wells. Each sample was transferred into three 40-milliliter (ml) EPA- <br />approved volatile organic analysis (VOA) vials without preservative. Care was taken to <br />ensure that visible air bubbles were not present in the vials after filling and capping. <br />Groundwater sample containers were properly labeled, placed in a chilled container and <br />transported under chain-of-custody protocols to Cal Tech Environmental Laboratories <br />(CTEL), a California Department of Public Health-certified laboratory, for analysis. The <br />influent groundwater samples were analyzed for the following: <br />Total petroleum hydrocarbons quantified as gasoline (TPH-g), in accordance with <br />EPA Method 8015 Modified; and <br />Benzene, toluene, ethylbenzene, and xylenes (BTEX), and the fuel additive methyl- <br />tertiary-butyl ether (MTBE) in accordance with EPA Method 8260B. <br />The requirements of the City of Stockton discharge permit include monthly monitoring and <br />sampling of effluent groundwater; effluent sampling was performed monthly. Each effluent <br />sample was collected into three VOA vials and a 1-liter amber bottle without preservative. <br />Advanced GeoEnvironmental, Inc.