Laserfiche WebLink
1 <br /> ... were advanced to approx.znare.-y 65 feet bgs Sod oorin2s VE'W1, ��E`V2 d ,TE'X vere <br /> camuleted as 2- rich diameter vapor extraction wells ana sou borings MW5, MW6. and ?VfW7 <br /> were completed as 2-inch diameter groundwater monitoring welts Boring CPT1 was advanced <br /> to approximately 100 feet bgs utilizing a truck-mounted cone penetration test (CPT) rig A soil <br /> vapor e-araction pilot test was conducted which yielded a radius of influence (ROI) of <br /> approximately 30 feet. at a vacuum of 11 5 inches of water_ Approximately 2 64 pounds of total <br /> petroleumhvcirocarcons quantified as Qasoline (TPHg). benzene toluene. ethylberizene. and <br /> �yleiies (B i EY) were removed during the vapor e.traction pilot test Soil vapor exiraction <br /> ' appeared to be a viable method for remediating TPHg and BTEX impacted soil at the site_ Field <br /> activities and analytical results are detailed in ATC's Remedial InvestigationiFeasibility Study. <br /> dated November 19, 2002. <br /> ' From October 2004 through April 2005,ATC performed six monthly high vacuum dualP hase <br /> extraction events at the site The high vacuum dual phase extraction remedial action was <br /> conducted using mobile extraction equipment equipped with a liquid-ring blower and associated <br /> flow rate and pressure measuring equipment During the initial event, ATC extracted from wells <br /> VEW1, 'VEW3, and MW2 to compare extraction removal rates. The remedial action was <br /> ' conducted during monthly events, each having a duration of approximately five days or forty <br /> hours. Vacuum influence and depth to water was monitored at the observation wells to evaluate <br /> the radius of vacuum influence and groundwater draw down. Based upon monitoring of the <br /> influent vapor with a PID during the vapor extraction events and analytical results of vapor <br /> samples collected from well MW2, approximately 436 pounds of petroleum hydrocarbon <br /> constituents were removed during the vapor extraction test 7 _ <br /> Historical soil and groundwater analytical data is presented in Tables 1 and 2, respectively. <br /> I4.0 HIGH VACUUM DUAL PHASE EXTRACTION <br /> Hagh vacuum dual phase extraction events were performed at the site in an effort to remediate the <br /> hydrocarbon-impacted vadose and capillary fringe zone soils The methods and procedures and <br /> the results are discussed m the following sections <br /> 4.1 WiLgh Vacuum Dual Phase Extraction Methods and Procedures <br /> From June through October 2005, ATC performed 15 high vacuum dual 2hase extraction events ? <br /> over a two month period at thq_stg..During each extraction event, ATC extracted from <br /> monitoring well lhW2. the well with the highest histone dissolved-hydrocarbon concentrations <br /> tThe June_Ociober 2005 extraction event was the second phase of soil vapor extraction which <br /> �1 began in October 2004 and was completed m Apri-12005-, The results of the initial events <br /> (Reporting Event 41) are detailed in ATC's Remedial Activities Summary Report dated June 18. <br /> ' 2005 Additionally, the information presented within this report also summarizes the results of <br /> the initial extraction event. <br /> 3 <br /> s%envimmentaA62577—diesel Pa1Vegorts1mtenm_rema 2 doc <br />