Laserfiche WebLink
Mr Kyle Christie Project 0805-140 03 <br /> October 5, 1995 <br /> Page 6 <br /> i <br /> Aeration Activities <br /> Based on subsurface investigations from borings drilled adjacent to the proposed new tank <br /> cavity, it is EMCON's opinion that composite samples collected from the soil generated <br /> from the excavation of the new UST well not exceed concentrations of TPHG greater than <br /> 50 ppm Therefore, it is unlikely that soil aeration will be necessary However in the event <br /> that TPHG concentrations exceed 50 ppm, the following items well be performed <br /> • Prior to initiating any soil aeration, EMCON will obtain a permit from the San <br /> Joaquin Valley Unified Air Pollution Control Department(SJVUAPCD) <br /> • EMCON will adhere to the allowable emission rates established by the <br /> SJVUAPCD when conducting soil aeration After aeration is complete, a <br /> composite sample will be collected from every 100 cubic yards generated The <br /> samples will be composited by the laboratory and will be analyzed for TPHG and <br /> BTEX <br /> • Results of analyses of samples collected from the soil will be used by ARCO's <br /> • contractors to evaluate disposal options <br /> Well Installation Activities <br /> Vapor Extraction Well <br /> • Once the old tank cavity has been backfilled with soil generated from the old tank <br /> complex excavation, EMCON will observe a licensed well driller drill one <br /> 10-inch-diameter soil boring in old tank cavity The boring location is shown on <br /> Figure 2 The boring well be drilled to the bottom of the old tank cavity <br /> (approximately 15 feet bgs) A 4-inch-diameter vapor extraction well will be <br /> installed in the boring (VW-5) and will be screened from approximately 5 feet <br /> bgs to the total depth The purpose of this well is to provide soil vapor extraction <br /> coverage in the old tank cavity above 20 feet bgs, if warranted <br /> • Undisturbed soil samples will be collected for classification and laboratory <br /> analyses at 5-foot intervals or at soil changes, from the ground surface to the <br /> total depth of the borings <br /> • Drill cuttings will be stored onsite and placed on, and covered with visqueen <br /> Four soil samples will be collected from the drill cuttings to be composited into <br /> one sample at the laboratory for evaluation of disposal options <br /> SACH'ARCO105481DESIGNV08051400 3AS-95 wpt 3 <br />