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r� rr i + • with the spacing of the cut rent recovery wells These two new wells f o i m a barrier fat the movement of contaminated groundwater acioss the entire northern and western (downgiadient) end of the property The gi oundwatei-r ecovei y wells were drilled with a di ill t tg equipped with 8-inch diameter hollow-stem augers by West Hazmat Drilling Corp of Rancho Cordova, California between November 27 and 29, 2001 The wells were constructed with 2-inch diainetei flush thteaded, schedule 40 0 020-inch factory slotted PVC well screen and blank casing The wells were screened between 9 and 19-feet bgs to allow for pumping from the entire thickness of the water bearing zone, from above the top of t h e highest historical water level to the bottom of the aquifer dust above the silty clay layer Blank casing was installed above this screened interval Lonestar #2112 sand was placed between the well casing and the boring from the bottom of the boring to 2-feet above the screened interval A 1 - foot thick bentonite layer was placed between the sandpack and t h e overlying cement sanitary seal A Portland cement sanitary seal was placed above the bentonite layer to prevent surface water from infiltrating into the well The wellheads were piped directly into t h e existing NEEP system manifold using buried I-inch diameter schedule 40 PVC pipe (Figure 3) See Appendix C for the well completion logs 3 -4 Well Develop On December 4 and 5, 2001, ASE associate geologist Erik Paddlef of d developed each of the AS and groundwater recovery wells using multiple episodes of surge-block agitation and bailer and pump evacuation Over ten well casing volumes of water were removed from each well during development, and evacuation continued until the water was relatively clear Well development purge water was remediated by the on-site groundwater treatment system No free-floating hydrocarbons or sheen were present on the surface of groundwater during well development 4 . 0 REMEDIATION SYSTEM COMPONENTS 4. 1 Vapor-Extraction Abatement Device The in-situ VE system uses a 300 cubic inch displacement, six cylinder internal combustion (IC) engine unit to oxidize extracted hydrocarbons The IC engine is equipped with a power take off (PTO)-driven blower-type vacuum pump (Roots #33) to extract volatile gasoline-laden air (soil gas) • from the VE wells (Figure 4) Under current operating conditions, the VE Frank's One Stop ASNE Remediation System Installation Report — February 2002 -3-