ARCHIVED REPORTS XR0009024 - Laserfiche WebLink

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C A M B R I A A Cambria geologist will supervise the drilling and describe encountered soils using the Unified Soil Classification System and Munsell Soil Color Charts Soil samples from the borings will be collected at five-foot intervals for soil description, possible chemical analyses, and organic vapor screening with a PID Cambria will prepare an exploratory boring log for each well, and PID measurements will be recorded on the boring logs Soil samples designated for cherrucal analyses will be retained in stainless steel or brass sample tubes The tubes will be covered on both ends with Teflon sheets and plastic end caps Soil samples will be labeled, entered onto a chain-of-custody record and placed into a cooler with ice for transport to a State of California certified laboratory for analyses A standard two-week turn- around time will be requested for laboratory results Monitoring Well Installation: Wells MW-11 and MW-12 will be completed using two-inch diameter Schedule 40 PVC casing, and well MW-13 will be completed using four-inch diameter Schedule 80 PVC casing Wells MW-11 and MW-12 will be screened approximately five feet above and ten feet below first encountered groundwater First encountered groundwater, based on the third quarter 2002 sampling event, is approximately 51 fbg Well MW-13 will be • screened from approximately 90 to 100 fbg, based on soil types at that depth The sandpack will be placed along the entire screened interval and two feet above the top of each well screen followed by a two-foot thick bentonite seal and cement grout to grade Actual well construction details will be based on field conditions at the time of drilling The wells will be secured with a locking cap under a traffic-rated well box i Well Development and Sampling- Blaine will develop the new groundwater monitoring wells prior to sampling After well development, Blaine will sample all the site groundwater monitoring wells and submit the samples to State of California certified laboratory for chemical analyses Groundwater samples from all wells will be analyzed as discussed in the recommendations above Soil Analyses Historically, TPHg, xylenes,MTBE, and TBA have been detected in soil beneath the site Therefore, selected soil samples collected from the borings will be analyzed for TPHg by EPA Method 8015 (Modified) or equivalent, BTEX by EPA Method 5020 or equivalent, and MTBE and TBA by EPA Method 8260B Wellhead Survey Activities: Following monitoring well installation, a licensed surveyor will I survey wellhead elevations relative to mean sea level and each well's latitude and longitude I 0955 10