Laserfiche WebLink
Ms Margaret Lagorio Project 797615 <br /> September 10, 1999 <br /> Page 2 <br /> WELL SAMPLING <br /> The on-site water supply well was sampled on August 19, 1999 to assess potential <br /> groundwater impacts from the residual hydrocarbon mass in soil Samples were <br /> submitted to a state-certified analytical laboratory and analyzed for total petroleum <br /> hydrocarbons as gasoline (TPHG) and benzene, toluene, ethylbenzene, and total xylenes <br /> (BTEX) using DHS LUFT Methodology and for oxyenates using USEPA Method 8260 <br /> Petroleum hydrocarbons, including oxygenates, were not detected in the samples <br /> collected from the water supply Copies of certified analytical reports are presented in <br /> Appendix B <br /> Depth to water recorded in the well at the time of sampling was 39 85 feet Groundwater <br /> was not encountered during site characterization activities that included installation of <br /> borings and vapor extraction wells to depths of 115 feet bgs The measured water level is <br /> likely in response to local artesian conditions and does not reflect the true depth to the <br /> water table in the site vicinity <br /> MASS ESTIMATE REVISIONS <br /> The mass of TPHG and total BTEX was calculated as follows <br /> Mass TPHG(lb) Vol of TPHG X soil density (lb/f[3) X TPHG cone (ppm) <br /> impacted soil (ft3) <br /> The measured dimensions of the UST excavation were 78 feet by 40 feet by 25 feet in <br /> one area and 20 feet by 25 feet by 18 feet in a second area The volume of this excavation <br /> is approximately 87,000 cubic feet at an average stockpile concentration of 242 ppm <br /> TPHG and 62 9 ppm total BTEX Mass removal estimates for TPHG and BTEX using <br /> the above equation would yield approximately 2315 pounds of TPHG and approximately <br /> 602 pounds of BTEX removed from the site These masses were subtracted from the <br /> calculated masses for TPHG and BTEX <br /> The estimated petroleum hydrocarbon mass (TPHG) using historical soil analytical <br /> results is approximately 203,072 pounds The estimated total BTEX mass is <br /> approximately 17,941 pounds The breakdown by soil interval is summarized below <br /> CP 1CWrchive\Arco16I00\Reports\6100p101 doc doc-9811sg 1 <br /> Pinnacle <br />