ARCHIVED REPORTS_XR0006819 - Laserfiche WebLink

Home Browse Search

A Cambria geologist supervised the drilling and described encountered soils using the Unified Soil Classification System and Munsell Color chart Encountered lithology is described on the exploratory boring logs presented in Appendix A Soil samples were collected from the borings at five-foot intervals for lrthologic description, potential chemical analysis, and head-space analysis Soil samples from each interval were screened for the presence of organic vapors using a photo ionization detector (PID) PID readings are recorded on the boring logs Monitoring Well Installations: Borings MW-4 through MW-7 were completed as ground water monitoring wells constructed of 2-inch diameter threaded Schedule 40 PVC well casing Well screen was placed in the first encountered water-bearing zone from 35 to 55 fbg in each of the wells Well construction included the placement of filter pack sand across the screened interval and two feet above the top of the screen interval A two foot thick bentonite seal was placed above the sandpack followed by a cement-grout seal to grade The well was secured with a locking well plug and a vault box Well surface seals were inspected and approved by an SJCPHS representative Well completion details are presented in Table 1 and on the exploratory boring logs contained in • Appendix A The elevations of the wells were surveyed by a licensed surveyor The top of casing and top of vault box elevations for the wells were surveyed to the nearest 0 01 foot relative to site datum Ground Water Sampling and Well Development: On October 10, 1997, Blaine Tech Services (Blaine) of San Jose, California developed Wells MW-4 through MW-7 by surging and pumping the wells Well development data are included in Blaine's Quarterly Monitoring Report presented in Appendix B Blaine measured water levels in Wells MW-1 through S-7 and VEW-2 and collected ground water samples from Wells MW-1 through MW-7 on October 9 and 10, 1997 Ground water samples were transported to *Sequoia Analytical of Redwood City, California, a state-certified environmental laboratory, for chemical analyses The samples were analyzed for Total Purgeable Petroleum Hydrocarbons calculated as gasoline (TPPH) according to EPA Method 8015 (Modified), benzene, toluene, ethylbenzene, and Xylenes (BTEX) and methyl-tertiary-butyl ether (MTBE) according to EPA Method 8020, and Oxygenates (ethanol, methanol, tertiary butanol, MTBE, DIPS, ETBE, and TAME) according to EPA Methods 374 3