Laserfiche WebLink
IT Corporation <br /> July 13, 1999 A Member of The IT Group <br /> Page 3 <br /> 4 Historical groundwater data is presented in the First Quarter 1999 <br /> Groundwater Monitoring &Sampling Report prepared by Gettler-Ryan <br /> (Attachment B) <br /> 5 Vertical and lateral concentration contours of contaminants found initially and <br /> those remaining in soil and groundwater, both on and off site <br /> Obviously impacted soil below dispenser islands was removed during dispenser <br /> upgrade activities A total of 70 tons of soil was removed during dispenser <br /> upgrade activities Initial groundwater and soil concentrations collected during <br /> Geoprobe®and monitoring well installation are included on Figures 6 and 7, <br /> respectively Current groundwater data 1s included in the First Quarter 1999 <br /> Groundwater Monitoring&Sampling Report prepared by Gettler-Ryan <br /> (Attachment B) Impacted soil remaining at the site is discussed in the following <br /> section <br /> 6 Mass balance calculation of the substance treated versus that remaining <br /> Based on soil data collected during dispenser upgrade activities the estimated <br /> mass of TPH-g initially present below the dispenser plumbing was approximately <br /> 253 kg The estimated mass of TPH remaining in the soil after over-excavation is <br /> approximately 79 2 kg Assumptions and calculations are included in <br /> Attachment C <br /> 7 Technology used to clean the site, if Best Available Technology(BAT) was not <br /> used, explain why <br /> Obviously impacted soil was removed during product dispenser upgrade <br /> activities Excavation and disposal was the BAT used to clean the site A total of <br /> 70 tons of impacted soil was removed during dispenser upgrade activities <br /> Removed soil included excavated and over-excavated material <br /> 8 Zone of influence calculated for the subsurface remediation system and the zone <br /> of capture attained for the soil and groundwater remediation system <br /> At the locations of PD-1, PD-2 and PD-4 the limits of excavations measured <br /> approximately 5 feet long by 5 feet wide and approximately 5 feet into native soil <br /> At the location of PD-3 the removal of impacted soil was limited to an area of <br /> approximately 2 feet long by 2 feet wide and approximately 2 feet below the <br /> dispenser The extent of impacted soil remaining at the site is estimated to be 5 <br /> feet long, 5 feet wide and 5 to 10 feet deep as shown in the calculations included <br /> in Attachment C Active groundwater remediation was not conducted or <br /> necessary at the site <br /> 9110071 B/0102/Closure <br />