WORK PLANS - Laserfiche WebLink

Home Browse Search

Mr.Frank Girardi December 3,2007 CONESTOGA-ROVERS &ASSOCIATES borings will be targeted for groundwater sample collection. We will attempt to collect groundwater samples at three depth intervals (e.g., 50, 65, and 80 fbg) in borings CPT-1 through CPT-3 for vertical assessment. Groundwater samples from the CPT borings will be collected using Hydropunch sampling equipment. Each groundwater sample will be collected from a separate boring to minimize the possibility of cross-contamination during sampling. For the HSA borings, a CRA geologist will supervise the drilling and describe encountered soils using the Unified Soil Classification System. Soil samples from borings MW-7 and MW-8 will be collected at 5-foot intervals for soil description, possible chemical analyses, and organic vapor screening with a photo-ionization detector (PID). CRA will prepare an exploratory boring log for each well boring and will record PID measurements on the boring logs. CRA will retain soil samples designated for chemical analyses in stainless steel or brass sample tubes. CRA will cover the tubes on both ends with Teflon sheets and plastic end caps, label the soil samples, enter them onto a chain-of-custody record, and place them into a cooler with ice for transport to a State- of-California-certified laboratory for analyses. Monitoring Well Installation: Borings MW-7 and MW-8 will be drilled to approximately 10 feet below first encountered groundwater. The wells will be constructed using 4-inch diameter Schedule 40 PVC casing. The well screen interval will be from approximately 5 feet above to 10 feet below first encountered groundwater. The sandpack in each well will be placed from the bottom of the well screen up to 2 feet above the top of the well screen, followed by a 2-foot thick bentonite seal and cement grout to grade. Actual well construction details will be based on soil types and field conditions during drilling. Each well will be secured with a locking cap under a traffic-rated well box. Well Development and Sampling: Blaine Tech Services, Inc. (Blaine) of San Jose, California will develop the new groundwater monitoring wells prior to sampling. After well development, Blaine will sample the groundwater monitoring wells and submit the samples to a State-of-California-certified laboratory for chemical analyses. Wellhead Survey Activities: Following monitoring well installation, a licensed surveyor will survey wellhead elevations relative to mean sea level and the wells' latitude and longitude. Soil samples designated for chemical analysis will be retained in stainless steel or brass sample tubes. The tubes will be covered on both ends with TeflonTM sheets and plastic end caps. Groundwater samples will be contained in appropriate sample containers. Soil and groundwater samples will be labeled, 1641 4 Worldwide Engineering,Environmental,Construction,and IT Services