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ATC Associates Inc. <br /> (YAT <br /> 1I!7 Lone Palm Avenue,Suite 1 Modesto,California -2221 <br /> 209-579-2221 <br /> Fax:209-579-2225 <br /> i <br /> i <br /> constructed of poly vinyl chloride (PVC) or stainless steel. When the tool has been driven to the <br /> depth of the projected water bearing zone, the outer part of the tool is retracted exposing up to 60 <br /> inches of.010 inch slot size filter screen allowing groundwater to infiltrate through the filter screen <br /> and into the tool's collection chamber. A stainless steel bailer is then lowered inside the hollow <br /> push rods until it is immersed in this chamber. While the sampler is advanced, O-ring seals and the <br /> expendable drive point will provide a watertight system to ensure sample integrity. ATC estimates <br /> three groundwater samples will be collected from each boring. <br /> All drilling activities will be conducted by a State-licensed C57 drilling company. A field geologist <br /> will be present to supervise drilling activities, determine sample depths, and collect groundwater <br /> samples. Following the collection of groundwater samples,the borings will be grouted to the surface <br /> with a neat cement slurry mixture using a tremmie pipe. Drill cuttings, if any, will be stored on site <br /> in 55-gallon drums pending laboratory results <br /> If GPT data indicate multiple water bearing zones and analytical data indicate an impact of <br /> petroleum hydrocarbons to groundwater in a lower water bearing zone, additional investigation may <br /> i <br /> be warranted including the installation of additional groundwater monitoring wells. <br /> Installation of Vapor Extraction Wells <br /> I <br /> Three soil borings will be advanced in the immediate vicinity of the former UST using a hollow <br /> stem auger equipped drill rig to depths of approximately 50 feet bgs. Proposed boring locations are <br /> shown on Figure 2. Soil samples will be collected at five-foot intervals or significant changes in <br /> lithology. Drilling will be conducted by a State licensed (C57) drilling company. Afield geologist <br /> will be present to log all drill cuttings and soil samples. Each soil sample will be field screened <br /> with a Photoionization Detection (PID) meter or similar instrument and at least two samples from <br /> each of the borings, based on field observations (i.e. odor, discoloration, PID readings), will be <br /> placed in a cooler with ice and submitted for laboratory analysis. <br /> The three borings will be completed as vapor extraction wells. The wells will be constructed of 2- <br /> inch inside diameter schedule 40 P=SC <br /> nd casing. The wells will be screened from <br /> approximately 35 to 50 feet bg Acreen slot and #2/12 mesh sand pack will be <br /> used. Neat cement will be used accordance with California Well Standards <br /> (December 1981). To protect the integrity of the wells, locking, water-tight well plugs will be <br /> installed on each well and a,water-tight wellhead labeled "monitoring well" will be concreted over <br /> each well. Proposed boring locations are sho ure 2. Proposed welLconstrttction details are j <br /> shown on Figure 3. _ <br /> I <br /> Jamar Service Station 4 <br /> ! <br />