ARCHIVED REPORTS_XR0011663 - Laserfiche WebLink

Home Browse Search

03 July 1998 AGE-NC Project No. 98-0438 Page 2 of 5 2.3. GROUND WATER DEPTH AND FLOW DIRECTION The estimated depth to ground water at the property is approximately 40 to 50 feet below surface grade(bsg),based on the map titled Lines of Equal Depth to:Groundwater Spring 1996 published by the San Joaquin County Flood Control District and Water Conservation District(FCD&WCD). The map shows the site to be in an area where ground water flows toward the northeast,but this may be modified by changing recharge and discharge patterns. 3.0. SCOPE OF WORK .3.1. DRILLING AND SAMPLING r The analytical results from soil samples collected during the UST removal and soil borings indicated that soil, and potentially ground water,may be impacted by petroleum hydrocarbons.Therefore,the PHS-EHD has request the lateral and vertical definition of both the hydrocarbon-impacted soil and possible ground water. The proposed scope of work presented in this work plan includes the installation of one soil boring, completion of the boring as a two-'inch diameter'ground water monitoring well and the collection of a ground water sample. The proposed soil boring locations are`illustrated in Figure 2. The well design specifications are illustrated in.Figure 3 :Monitoring Well Design. Each boring will be advanced utilizing a truck-mounted drill rig equipped with 8.25-inch hollow- stem augers. Soil samples will be collected at five-foot intervals beginning at 5 feet bsg in each boring. Samples will be collected using'a California split-spoon sampler and,brass sleeves. Samples will be driven by dropping a 140-pound weight from a height of 30 inches. The number of blows required to drive each 6-inch length of the sampler (blow counts)will be.recorded on boring logs maintained by an AGE staff geologist. Upon sample retrieval, the middle brass sleeve will be removed from the sampler: The ends of the , sleeve will be immediately covered with,Teflon or aluminum sheets,'sealedwith plastic end caps, secured with tape and immediately placed under ice in a chilled container for transportation to 'a state-certified laboratory. Each soil sample sleeve will be labeled with the boring designation, vertical depth,time, date.and sampler's initials. 3.2. . EQUIPMENT DECONTAMINATION All sampling.tools and brass sleeves used for sample collection will be thoroughly rinsed with clean Advanced GeoEnvironmental, Inc.