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{ ' 14M , • May 2003 AGE-NC Project No 010865 ' Page 3 of 5 L ' 2 2 2 Aquifer Response Analysis r Ground water levels in the seven observation wells all appeared to be influenced with measurable ; draw-down during the pumping test The maximum ground water draw-down in wells EW-2 and the six observation wells versus the distance of each well from the extraction point were graphed on semi-loganthmlc paper(Appendix B) Utilizing the Distance-Drawdown Method(Jacob straight-line ' method), general transmissivrty, storahvlty and hydraulic conductivity values were determined for the three pumping rates transmisszvity was calculated at approximately 230 ftZ/day, storativity calculated at between 0 007 and 0 026,hydraulic conductivity was determined to be approximately 1 0 031 cm/sec (Appendix D) and an inferred radius of influence was projected at between 80 and 82 feet,(Appendix B) Results of the aquifer ground water pumping test are summarized in Table 2, , a site plan depicting the radius of influence during the 19 July 2001 pumping test is depicted in Figure 3 ' 2 2 3 Effluent Water Sampling Procedures ,. Two grab water samples, one collected during the 4 GPM step and one from the 5 GMP step, were collected from. the discharge hose directly into three 40-m1 EPA-approved VOA vials containing 0 5 ml 18% hydrochloric acid as a sample preservative and one 1-liter amber bottle without 1 preservative Following'sample collection,the samples were properly labeled,logged on a chain-of- custody form,placed in a chilled container and transported to McCampbell Analytical Inc (MAI), a Califorma Department of Health Services-certified laboratory for the following analyses ' Total petroleum hydrocarbons 4uantlfied as gasoline (TPH-g) and diesel (TPH-d) in accordance with EPA Method 8015 Modified and ' Benzene, toluene, ethyl benzene and total xylene (BTEX) and methyl tertiary-butyl ether (MTBE) in accordance with EPA methods 8020 - 22-4 Extracted Water Analytical Results TPH-g and TPH-d were detected in the two grab water samples at concentrations as high as 16,000 micrograms per liter (µg/l) and 1,600 µg/l, respectively, from the 4 GPM sample BTEX compounds were detected In the two samples at concentrations as high as 250 µg/1 benzene, 2,100 f µg/l toluene, 460 µg/1 ethylbenzene and 2,600 µg/1 xylenes, from the 4 GMP sample Laboratory results are summarized on Table 3 The laboratory report (MAI Lab IDs 73119 and 73120) and 1 chain-of-custody forms are presented in Appendix E ti Advanced GeoEnvironmcntal,Inc 1