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ATTACHMENT A <br /> FIELD AND LABORATORY PROCEDURES <br /> Drilling <br /> Subsurface soil samples will be collected using an eight-inch hollow stem auger to <br /> approximately 15 to 20 feet below ground surface Borings will be logged by a SECOR <br /> International Incorporated geologist using the Unified Soil Classification System and <br /> standard geologic techniques Soil samples for logging will be collected at 5-foot depth <br /> intervals using a California-modified split-spoon sampler All down-hole drilling and <br /> sampling equipment will be steam-cleaned following the completion of the soil boring <br /> Down-hole sampling equipment will be washed in a tri-sodium phosphate or alconox <br /> solution between samples <br /> Groundwater Monitoring Well Installation and Development <br /> Soil bonngs will be converted to groundwater monitoring wells by installing 2-inch <br /> diameter, flush-threaded, Schedule 40 PVC casing with 0 020-inch factory-slotted screen <br /> Approximately 15 feet of screen will be placed in the bottoms of the borings A grade of <br /> sand appropriate to the screen size will be placed in the annular space across the entire <br /> screened interval, and will extend approximately 1 foot above the top of the screen for the <br /> wells A bentonite seal will extend 2 feet above the sand pack The monitoring wells will <br /> be completed with neat cement from the bentonite seal to the ground surface The well <br /> casing will be topped with a locking cap The well head will be contained in a watertight <br /> traffic-rated well box The boring logs will show well construction details <br /> The wells will be developed after completion The development procedure for each well <br /> will consist of surging the well, then pumping or bailing water from the well until the water <br /> is visibly clear, the well goes dry, or until a maximum of ten casing volumes have been <br /> removed <br /> The newly installed wells will be surveyed by a California State Licensed Surveyor The <br /> well casings will be surveyed to the nearest 0 01 feet in elevation to a known benchmark <br /> Groundwater Sampling Procedures <br /> . Sampling equipment will be thoroughly cleaned prior to each sample The sampling <br /> procedure for each well includes of measuring the water level and checking for the <br /> presence of separate-phase hydrocarbons (SPH), using either an electronic indicator and a <br />