Laserfiche WebLink
1 V, . <br /> 1 �Tc <br /> A S S 0 C I A T E S I N C <br /> 2_4 M_onitorine Well Development <br /> 1 Groundwater monitoring well MW1 was developed on September 28, 1998 The well was <br /> purged until the extracted water was relatively sediment free Development/purge logs are <br /> included in Appendix B Purgewater was temporarily stored on site in 55-gallon drums After the <br /> 1 fluid level had been allowed to stabilize, the groundwater level was obtained from well MWl <br /> The fluid level was taken on September 28, 1998, utilizing an electronic water probe capable of <br /> measuring with an accuracy of 11100 of a foot Groundwater was measured at a depth of 50 09 <br /> 1 feet below top of casing <br /> 1 2_5 Groundwater Sampling and Analysis <br /> On September 28, 1998, a groundwater sample was collected from well MW 1 The sample was <br /> 1 collected after purging a minimum of three well volumes and stabilization of electric conductivity, <br /> pH, and temperature Field development/purge logs are presented in Appendix B Subsequent to <br /> purging, groundwater was sampled and transferred to appropriate sample containers, using a <br /> 1 clean, disposable bailer with a bottom emptying device to reduce volatilization Sample <br /> containers were then labeled with sample identification, placed on ice, and shipped under chain-of- <br /> custody to Sequoia Analytical <br /> The groundwater sample from well MW1 was analyzed by Sequoia for TPHg, TPHd, TPHk, <br /> BTEX, and oxygenate fuel additives Groundwater analytical results are summarized in Table 2, <br /> ' and laboratory data sheets are presented in Appendix C <br /> 3.0 SUBSURFACE CONDITIONS <br /> 1 The upper 30 5 feet of the soil column encountered in soil boring MW 1 generally consisted of <br /> poorly graded sand and silty sand with lean clay present between 11 and 11 5 to 15 feet bgs <br /> 1 Lean clay was also encountered between 30 5 feet bgs and 36 5 to 40 feet bgs Soil from depths <br /> between 36 5 to 40 feet bgs and 46 5 to 50 feet bgs consisted of elastic silt with sand Soil from <br /> depths between 46 5 to 50 feet bgs and 66 5 feet bgs, the maximum depth explored, consisted of <br /> 1 poorly graded sand with varying amounts of silt <br /> 1 4.0 ANALYTICAL RESULTS <br /> 4.1 Soil Analytical Results <br /> 1 Petroleum hydrocarbon constituents were detected in soil samples collected from boring MW 1 at _ <br /> depths of 15 5, 20 5, 40 5 and 45 5 feet bgs The highest reported constituent concentrations in <br /> ' this boring were observed in the soil samples collected at 15 5 and 20 5 feet bgs The petroleum <br /> hydrocarbons appear to attenuate rapidly with depth as indicated by a reduction in concentrations <br /> of petroleum hydrocarbons of over sixty percent in the soil samples collected at 40 5 and 45 5 feet <br /> bgs No hydrocarbon analytes were reported in amiple-the sample collected from the bottom of <br /> the boring at 65 5 feet bgs <br /> W w2577Vrts\sunui dm 3 <br />