Laserfiche WebLink
1 2 3 Cone Penetration Testin and Discrete Groundwater Sampling <br /> On April 25, 2000, to evaluate the vertical extent of impacted soil and groundwater, Gregg Drilling <br /> and Testing, Inc (Gregg), a state licensed drilling contractor (C-57##656407), advanced one on- <br /> site cone penetration test (CPT) boring and collected discrete soil and groundwater samples at <br /> one on-site location <br /> Soil samples were collected into stainless steel sample sleeves with apush-driven soil sampler at <br /> 65, 70 and 74 feet bgs All three soil samples contained relatively low concentrations of at least <br /> one compound analyzed The sample collected at 65 feet contained 10 mg/kg of TPH-as- <br /> gasoline, 0 15 mg/kg of benzene, 0 14 mg/kg of toluene, 0 26 mg/kg of ethylbenzene, and 0 73 <br /> mg/kg of xylenes The sample collected at 70 feet only contained 0 0071 mg/kg of toluene, and <br /> the sample collected from 74 feet only contained 0 02 mg/kg of toluene, 0 0068 mg/kg of <br /> ethylbenzene and 0 05 mg/kg of xylenes The five oxygenate compounds, 1,2-dichloroethane <br /> (1,2-DCA) and EDB were not detected in any of the three soil sample analyses These soil <br /> sample analytical results are summarized in Table 1 <br /> Based on the CPT and pore pressure dissipation data, groundwater-bearing sand and gravel <br /> sequences were identified beneath the groundwater table at approximately 60 and 105 feet bgs <br /> Gregg discretely sampled the groundwater interval at 60 feet bgs using a SimulProbe The <br /> groundwater sample collected at 60 feet bgs contained 5,700 pg/l of TPH-as-gasoline, 76 pg/l of <br /> benzene, 61 pg/l of toluene, 53 pg/l of ethylbenzene, 280 pg/l of xylenes, and 11 pg/I of 1,2-DCA <br /> The five oxygenate compounds and EDB were not detected in the groundwater sample <br /> 1 2 4 Installation of Off-Site Monitoring Wells and Sensitive Receptor Survey <br /> On January 14, 2002, Ramage Environmental published Status Report, Additional Site <br /> Investigation, which documented the installation of four off-site groundwater table monitoring wells <br /> and the survey of potential sensitive receptors within 2,000 feet of the site The locations of the <br /> four new wells (MW-4, MW-5, MW-6 and MW-7) are shown on Figure 3 The well construction <br /> details are summarized in Table 2 <br /> All of the soil and groundwater samples collected from the four new wells were free of detectable <br /> concentrations of gasoline compounds As such, the lateral extents of impacted soil and <br /> groundwater at the water table appeared to be defined Based on the cumulative soil sample <br /> analytical data (Table 1), impacts to vadose zone soil appeared to be limited to the footprint of the <br /> former UST system <br /> 7 <br /> r <br />