ARCHIVED REPORTS_XR0005009 - Laserfiche WebLink

Home Browse Search

1.1 pg/1, 97 pg/l and 15,000 µg/l, respectively Benzene was not detected in wells MW-2, MW-5 and MW-6 Other BTEX compounds were detected In these wells at concentrations as high as 18,000 ltg/l (toluene, MW-4) Ethylbenzene and xylenes were detected in MW-3 at concentrations of 230 Ag/l for each compound No petroleum hydrocarbons were detected in the samples collected from wells MW-2 and MW-b, the newly installed down-gradient well MONITORING WELL INSTALLATION On 01 April 1998, soil boring MW-7 was advanced on the property directly east of the site The boring location is illustrated on Figure 2 The soil boring was advanced to a depth of 25 feet bsg Boring MW-7 was completed as a ground water monitoring well The well was completed using 2- inch diameter schedule 40 PVC casing with 0 02-Inch slotted screen from approximately 5 to 25 feet bsg A filter pack was installed using#2 Lonestar sand from 4 to 25 feet Bentonite chips were used to make a two-foot plug and the remaining annular space was backfilled to the surface with portland cement A traffic-rated well box (8-inch diameter)was installed over each well, in accordance with County regulations Samples were collected at five-foot intervals,with samples were preserved by covering both ends of the brass sleeve with Teflon sheets,capping and sealing with tape TPH-g,BTE&X and oxygenated compounds were not detected in soil samples collected from the location of well MW-7 Soil samples collected from depths of 15, 20 and 25 feet bsg were analyzed REMEDIATION WELL INSTALLATION On 29 July 1997, three in-situ air-sparing (lAS) points (IAS-7 through IAS-9) were installed to depths of 25 and 15 feet bsg using AGE's van-mounted Geoprobe 5400 soil probing machine Two probe bonngs were completed as IAS points using one 21-inch long, 318-inch I D stainless steel screen implant attached at 25 feet bsg to an anchor tip One additional probe boring was completed using one 21-inch long,318-inch I D stainless steel screen implant set at a depth of 15 feetbsg Vinyl tubing(3/8-inch O D )was extended from the sparging screen implant to the surface and a filterpack (fine glass beads)was installed around the screen implant from a depth of 20 to 25 feet bsg Bentonite sand (#8 bentonite)was used to make a 4-foot plug above the filter pack and the wells were grouted to surface grade with portland cement An eight-inch traffic box was installed at the surface for each IAS point SOIL VAPOR EXTRACTION - MASS OF RECOVERY Between 15 April and 19 September 2003, the ground water extraction and treatment system processed approximately 302,703 gallons of water The total volume of ground water treated as of 30 September 2003 Is approximately 2,459,705 gallons Advanced GeoEnvironmental,rine