Laserfiche WebLink
0 41 <br /> Former Countryside Market,Stockton,California <br /> Feasibility Study and Interim Remedial Action Plan May 20,2013 <br /> facilitate the existing rate of natural attenuation by stimulating these transformation processes. <br /> However, while intrinsic biodegradation is well recognized as an effective environmental remediation <br /> tool and approach (USEPA 1994), the final RAP may include another compatible technology to be <br /> used in conjunction and/or in sequence with sparging. <br /> 7.2 Sparge Treatment System Design <br /> SGI has prepared the following preliminary sparge treatment system design, based on assumed 20 foot <br /> AS well spacing grid, across areas of the Site and along Copperopolis Road where elevated <br /> concentrations of petroleum hydrocarbons have been detected in groundwater. The actual spacing of <br /> the AS wells will be based on the feasibility testing results. For the purpo�e of this preliminary sparge <br /> treatment system design, SGI has assumed typical AS wells will be utiliz d although the final design <br /> could be modified based on the testing results. <br /> SGI proposes to install approximately eight on-Site AS wells (including AS-1 and AS-2) and a total of 13 <br /> off-site AS wells along the northern and southern portions of Copperopolis Road. Four observation wells <br /> (two on-Site and two off-site) will also be installed at strategic Io ations to monitor system <br /> performance/effectiveness in conjunction with the existing network of groundwater monitoring wells. <br /> Additionally, one on-Site vapor well (VW-1) will be installed to more closely evaluate the effect of <br /> sparging within the vadose zone and as a potential remediation well. The approximate well locations are <br /> all shown on Figure B. <br /> During sparging operations, air will be injected into groundwater. The introduction of air will enhance in- <br /> situ aerobic biodegradation of petroleum hydrocarbon constituents in groundwater and/or result in direct <br /> volatilization. The AS, observation and groundwater monitoring wells willi be sealed to prevent gases <br /> from escaping through the respective casings. <br /> After the proposed wells are in place, conveyance piping will be installed below ground to connect the <br /> wells to the above ground distribution manifold located in a proposed treatment compound to be <br /> approximately located in the northeastern portion of the Site. To distribute air from the generation <br /> equipment to individual AS well locations, dedicated pressure rated air ose/tubing contained within <br /> Schedule 80 PVC piping will be utilized in an effort to minimize the amount of below ground conveyance <br /> piping installed beneath Copperopolis Road. <br /> The proposed system will utilize a network of vertical AS wells and lateral conveyance lines to facilitate <br /> treatment of impacted groundwater. A process flow diagram for the sparge system is provided as <br /> Figure 9. All equipment will be installed and wired with appropriate alarm shutdowns and safety <br /> interlocks. SGI and the selected construction contractor will use engineering plans and equipment <br /> specifications to procure the necessary permits/approvals, including San Joaquin County Environmental <br /> Health Department well permits and a Public Works Department encroac ment permit. All necessary <br /> approvals will be obtained prior to system installation, and all final ins ctions will be completed in <br /> conjunction with the final installation. <br /> Feasibility Study an FeasV4 ShAy 81 RAP Te Find,A 7-2 The Source Group,Inc. <br />