Laserfiche WebLink
CreolagccalTechnics Inc Page 7 <br /> Feasibility Study&Investigation Work Plan <br /> Cardoza{Main St) <br /> Project No 662 2 <br /> April 19,2004 <br /> 1 remediation This will consist of soil vapor extraction from shallow extraction well <br /> EW-2 <br /> ' 2 Groundwater Extraction Test - measuring water level drawdown in surrounding <br /> monitoring wells to determine aquifer characteristics for groundwater remediation <br /> This will consist of extracting groundwater from existing well EW-1 Well EW-2's <br /> well screen is expected to be dry as drawdown occurs in EW-1 so vapor extraction <br /> will continue from EW-2 during this second test <br /> Initially, the vapor/water extraction will be from strata of higher conductivity sands but the <br /> ' vacuum influences will eventually permeate the lower conductivity silty/clay units at 21 — <br /> 35 feet bgs recorded in MW-104 Well MW-104 was continuously cored and is located <br /> approximately 10 feet from EW-1 and 16 feet from proposed extraction well EW-2 The <br /> ' boring log for MW-104 is included in Appendix C As more fresh air is drawn into the soil, <br /> natural attenuation will be augmented through the introduction of oxygen to the anaerobic <br /> environment <br /> The existing monitoring wells will also provide observation points to monitor vacuum <br /> influence and draw down in the aquifer The following wells will be fitted with Solinst <br /> Level Loggers and vacuum caps <br /> Well iam. Screen Distance from - <br /> MWi <br /> - - <br /> MW-2 271 57' <br /> — easurementsase on p <br /> ma istances <br /> ** =Measurements based on proposed map distances <br /> ' Soil vapor and groundwater samples will be collected during the course of extraction to <br /> evaluate the concentration changes through the test period Influent soil vapor samples will <br /> 1 be collected at the beginning of extraction and at 8-hour increments Groundwater samples <br /> will be collected prior to start of pumping, immediately after pump startup, and then at 8- <br /> hour intervals from the effluent discharge pump <br /> ' 4.3 Laboratory Analysis <br /> Soil Vapor Analyses <br /> ' A vacuum pump will be used to collect influent air samples to the extraction system on a <br /> routine basis during the tests to evaluate mass transfer rates The air samples will be <br /> collected in a one-liter capacity Tedlar bag and submitted to Air-Toxics Ltd in Sacramento, <br /> California for analysis of BTEX, TPH-G and MTBE by method TO-3 We propose to <br /> ' collect up to 10 samples during testing <br /> The detection limits are listed below <br /> Detection—Limits BTEX MTBE TPH-U <br /> ir Gtg <br /> 1 <br />