Laserfiche WebLink
1 rl <br /> . Ms Margaret Lagorio Project 20805-140 010 <br /> August 10, 1998 <br /> Page 2 <br /> All drilling activities will be conducted by a California-licensed drilling contractor under <br /> the direction of a Pinnacle geologist A California-registered geologist will supervise work <br /> conducted during this assessment A discussion of activities to be conducted in each task <br /> are presented in the following sections Well installation and sampling methods are <br /> discussed in Appendix A and Appendix B, respectively <br /> Task 1 Prefield Activities <br /> Prior to implementing the site assessment and well installation activities, Pinnacle will <br /> obtain permits from the San Joaquin County Public Health Services, Environmental <br /> Health Division (SJCPHS/EHD) Underground utilities will be cleared by notifying <br /> Underground Service Alert and by using a private utility locator to confirm that utilities <br /> and other subsurface obstructions are not present at the proposed drilling locations <br /> Task 2 Installation of AS and SVE Wells <br /> Three AS wells and one dual completion SVE well will be installed for remediation <br /> purposes within and downgradient of the former UST complex (see Figure 2) The drilling <br /> activities will include soil sampling and HydroPunch® sampling to comply with the <br /> SJCPHS/EHD request for water table wells and vertical delineation of impacts <br /> AS Well Installation <br /> ARCO proposes to conduct the vertical delineation of impacts as part of the AS well <br /> installation task The AS well borings will be drilled using 8-inch hollow stem auger <br /> drilling equipment and soil samples will be collected at 5-foot intervals Drilling will <br /> proceed vertically until evidence of impacts is not present At the boring termination <br /> depth, a groundwater grab sample will be collected using the HydroPunch' sampler Two <br /> to three soil samples from the saturated interval and the HydroPunch® sample will be <br /> analyzed to assess the vertical extent of impacts This vertical delineation data will be <br /> evaluated to assess the necessity for deep monitoring wells at the site and to re-assess the <br /> scope of work for the proposed offsite assessment <br /> The depth intervals below 50 feet below ground surface (bgs) will be backfilled with <br /> bentonite chis to seal this portion of the borehole The three AS wells will then be <br /> constructed using 2-inch diameter PVC casing with the screen interval located between 48 <br /> and 50 feet bgs The filter pack will consist of number 3 sand and be placed to <br /> approximately 47 feet bgs A transitional bentonite seal, approximately 2 feet in thickness, <br /> sAC1A 1548ON DOC 961rntt 1 <br />