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Field-Activities <br /> Geocon proposes to trench ten locations to investigate potential impacts to soil and advance eight <br /> direct-push borings for grab-groundwater sampling. Global positioning system (GPS)equipment will <br /> be used to record the location of each area investigated. Proposed sample locations are depicted on <br /> Figure 4. <br /> Soil SaMDli7?g <br /> To evaluate the possible presence of heavy metals, petroleum hydrocarbons, and pesticide and <br /> herbicide residues, Geocon will obtain soil samples from selected locations on the UP parcels. Up to <br /> ten sample locations will be deterniined based on field observations and known locations of <br /> recognized environmental conditions. At each sample location, a backhoe will be used to trench <br /> approximately two to five feet bgs. Each trench will be field-screened for the presence of volatile <br /> organic compounds using a photo-ionization detector (PID). Soil samples will be collected at depths <br /> ranging from zero to 2 feet bgs or at the depth of the deepest impact, if any, as evidenced. by visual <br /> and olfactory observations and PID reading. Soil samples will be collected using pre-cleaned brass <br /> sample tubes or placed in laboratory-supplied glass jars. <br /> Soil samples collected for laboratory analysis will be labeled and transported to a California-certified <br /> analytical laboratory in an ice-chilled container, utilizing standard chain-of-custody procedures. <br /> Sampling equipment will be cleansed by washing the equipment with an Alconox solution followed by <br /> a double rinse with distilled water. The decontamination water will be containerized in a 55-gallon <br /> drum pending disposal. Upon completion of the soil sampling, trench spoils will be returned to each <br /> respective trench and leveled using the backhoe. <br /> Grab-Groundwater Sampling <br /> To evaluate and confirm the presence of petroleum hydrocarbons in groundwater, Geocon will <br /> advance up to eight borings in the UP parcels and collect grab-groundwater samples. Borings will be <br /> advanced using direct-push methods to approximately 2 feet below first encountered groundwater. <br /> Based on the previous investigations by others, Geocon anticipated that groundwater would be <br /> encountered at approximately 10 feet bgs. <br /> Grab-groundwater samples will be collected using Hydropunch sampling equipment or by inserting <br /> temporary PVC casing into each borehole. Samples will be placed iir, the appropriate laboratory- <br /> supplied containers, labeled, and transported to a California-certified laboratory in an ice-chilled <br /> container, under standard chain-of-custody procedures. <br /> Sampling equipment will be cleansed by washing the equipment with an Alconox solution followed <br /> by a double rinse with distilled water. Upon completion of the grab-groundwater sampling, each <br /> borehole will be tremie grouted. Soil cuttings and decontamination water will be placed in 55-gallon <br /> drums pending disposal. <br /> Prgiect No.$8675-06-01 -4- October 16,2003 <br />