WORK PLANS - Laserfiche WebLink

Home Browse Search

Geosyntec consultants 7.2.1 Cone Penetrometer Testing (CPT) As shown on Figure 7, up to 8 CPT borings will be advancedoff-siteand to the north of the CPT-13 area, andCone CPT boring (CPT-2013-1313) will be advanced adjacent to CPT-MIP-2012-1 The purpose of the CPT investigation is to (i) provide detailed information of the geology in the apparent downgradient direction of the CPT-13 area, and (ii) to identify appropriate depth intervals for sampling groundwater for analysis of toluene. Gregg Drilling & Testing, Inc. of Martinez, California, (Gregg) will provide the, equipment and personnel to perform the CPT work. All work will be completed under supervision of Geosyntec personnel. The CPT probe will be advanced to a minimum target depth of 40 ft bgs off-site and 60 ft at location CPT-2013-1313 (Figure 7). The following parameters will be measured or detected at 5 cm (0.16 ft) depth intervals at each CPT location: • Tip resistance(Qt); • Sleeve friction(Fs); and + Dynamic pore pressure(Ut). Soil behavior type (SBT) will be interpreted using relationships between these parameters. The SBT log from each location will be evaluated and used to select up to two groundwater sampling depth interval(s). r undwater Sampling 7.2.2 G o p g Up to two groundwater samples will be collected from borings immediately adjacent to each CPT location. Samples will be collected by advancing hollow CPT rods equipped with a disposable tip and filter screen to the desired sample depth interval and then retracting the rods approximately 2 to 4 feet to expose the screen. Samples will be collected using a stainless steel bailer. All sampling equipment will be decontaminated before sampling at each location. Groundwater samples will be collected into laboratory-supplied sample containers and labeled with project identification, sample location, analytical parameters,time and date of sampling, and sample preservative, if any. Groundwater samples will be stored in an ice-cooled chest, maintained at approximately 4°C, for transport under standard chain- CPT-13 Area Investigation Report and Work Plan 22 30 May 2013