Laserfiche WebLink
custody documentation. <br /> The monitoring well purge water was stored on site in the 55 <br />' gallon DOT drums containing the development water. <br /> 3 . 2 .4 Results of Groundwater Chemical Analyses <br /> Water samples from monitoring wells MW-1 through MW-5 were <br /> analyzed for TPHG (DHS Method) and BTEX (EPA Method 8020) . A <br />' trip blank labeled MW-6 (containing organic-free water) was also <br /> submitted and analyzed for the above referenced tests. <br />' Laboratory analyses by the above methods detected no TPHG or BTEX <br /> constituents in the water sample collected from MW-5 or the trip <br /> blank (MW-6) . The water samples taken from monitoring wells MW-1 <br /> through MW-4 detected TPHG in concentrations of 150 ppb, 190 ppb, <br />' 2400 ppb, and 190 ppb, respectively. BTEX constituents were <br /> detected in the water samples tested from each well . Certified <br /> analytical data sheets and chain-or-custody documentation are <br />' included in Appendix F and the results of chemical analyses are <br /> summarized in Table 2 . <br />' 4 . 0 FINDINGS <br /> 4 . 1 Groundwater Hydraulic Gradient <br /> The groundwater hydraulic gradient was evaluated by triangulation <br /> of stabilized depth to water in monitoring wells MW-2 , MW-3 , and <br />' MW-4 . The data collected from the 3 wells assumes that all of <br /> the wells are constructed within the same aquifer. TPE believes <br /> that all 3 wells are hydraulically interconnected. Elevations of <br /> the monitoring wells and potentiometric levels are shown in Table <br />' 3 . Groundwater elevations measured on August 3 , 1992 , ranged <br /> from -59 . 99 to -60 . 04 feet below mean sea level (MSL) , as shown <br /> on Table 3 . The Groundwater Hydraulic Gradient Map (Figure 5) <br />' shows that groundwater beneath the site flows toward the south by <br /> southeast with a relatively flat gradient of 0 . 0004 ft/ft. <br /> 5. 0 SUMMARY OF FINDINGS <br />' Groundwater beneath the site is estimated to flow in a <br /> southerly direction with a gradient of 0 . 0004 ft/ft. <br />' Soil samples located at the vadose zone/groundwater <br /> interface and samples selected based on field screening <br />' with a CGI were analyzed for TPHG and BTEX. <br /> Additionally, the soil sample showing the highest <br /> reading was analyzed for total lead. <br /> TPHG and some BTEX constituents were detected in at <br /> least one soil sample tested from each boring except <br /> 7 <br /> t <br />