ARCHIVED REPORTS XR0000470 - Laserfiche WebLink

Home Browse Search

Mr Kyle Christie January 11, 1995 Page 2 Quarterly Sampling Field and Analytical Methods GTI personnel measured depth-to-water, purged each well, and collected groundwater samples at the site Water-levels were measured before the wells were purged Prior to sampling, the wells were purged of a minimum of three well casing, volumes using a submersible pump or polyvinyl chloride (PVC) bailer After purging, each well was sampled using a disposable bailer Field data sheets and chain-of-custody documentation are included in Exhibit A GTI's field procedures are also included in Exhibit A The purge water generated during this sampling event was temporarily stored on site in 55-gallon barrels then transported off-site for proper disposal by Integrated Waste Stream Management All groundwater samples were analyzed for benzene, toluene, ethylbenzene, and xylenes (BTEX) and total petroleum hydrocarbons as gasoline (TPH-G) by U S Environmental Protection Agency (EPA) Methods 5030/8020/and 8015 Modified Quarterly Sampling Results and Discussion Water-level data for this site is presented in Table 1 Table 2 summarizes historical groundwater flow direction and gradient data for this site Figure 1 shows the water-level elevations for each well and the contours of equal water-level elevation for September 29, 1994 Water-level data collected from well E-6 was not used in Figure 1 because the well casing was altered during the incorporation of the well into the SVE/AS system and GTI's data are based on the altered well casing The well casing for this well will require resurveying Figure 2 shows BTEX and TPH-G concentrations for each well sampled, and-the approximate extent of=benzene-in�the-groundwater—Table3=presents-the=groundwater analytical data On September 29, 1994, the general groundwater flow direction was northeasterly under a hydraulic gradient of approximately 0 002 Because the GWES was not operating during construction of the SVE/AS system in September, 1994, groundwater flow was not influenced by the GWES Historically, groundwater flow direction is to the northeast under an approximate hydraulic gradient of 0 001 to 0 003 On September 29, 1994, depth-to-water ranged from 15 41 to 18 12 feet below ground surface (bgs) Water-level elevations have decreased an average of 1 06 feet (which includes E-3 through E-5, E-7 through E-12, BHD-1, BHD-2, PR-1, PR-2, and MW-1) since the last quarterly monitoring event (June 1994) The TPH-G and BTEX concentrations detected in the samples collected this quarter are generally consistent or lower than previously reported results in wells E-3, E-7, E-8, E-9, E-10, E-11, E-12, PR-1, PR-2, BHD-1, BHD-2, and MW-1 The TPH-G and BTEX concentrations detected in the samples from wells E-4 and E-5 are generally lower than have Y Draft Report—Useor disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document I27RREPORTS13Rr94QTR RPP