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y ATTACHMENT B FIELD PROCEDURES Chevron Service Station 9-1452, 334 East Main Street, Ripon, California boring Down-hole sampling equipment will be washed in a tri-sodium phosphate or alconox • solution between samples Groundwater Monitoring Well Installation The borings will be converted to a groundwater monitoring well by installing 2-inch diameter, flush-threaded, Schedule 40 PVC casing with 0 020-inch factory-slotted screen Approximately 15 feet of screen will be placed in the bottom of each boring A grade of sand appropriate to the screen size will be placed in the annular space across the entire screened interval, and will extend approximately 2 feet above the top of the screen for each well A bentonite seal will extend two feet above the sand pack The monitoring wells will be completed with neat cement from the bentonite seal to ground surface The well casings will be topped with a locking cap The well heads will be contained in watertight well boxes, either traffic rated and flush mounted or in a "stove-pipe" arrangement The boring logs will show well construction details The wells will be developed after completion by pumping or bailing water from each well until the water is visibly clear, the wells go dry, or until a maximum of ten casing volumes have been removed Laboratory Procedures for Soil and Groundwater Samples Soil and groundwater samples collected will be analyzed for the presence of TPHg and methanol by EPA Method 8015, BTEX, MtBE, DIPE, TAME, EtBE, TBA, EDB, 1,2-DCA, and ethanol by EPA Method 8260B Soil Cuttings and Rinsate Water Soil cuttings generated during drilling operations were / will be temporarily stored onsite and covered with plastic sheeting pending characterization and disposal Chevron's disposal contractor removed / will remove soil cuttings to an appropriate disposal facility Water generated during steam cleaning will be temporarily stored in DOT-approved 55-gallon drums pending transport by Chevron's disposal contractor to an appropriate disposal or treatment facility Soil cuttings and ransate water drums will be temporarily stored onsite for approximately 4 to 8 weeks Organic Vapor Procedures Soil samples collected at five-foot intervals during drilling were / will be analyzed in the field for ionizable organic compounds using a photo-ionization detector(PID) with a 10 2 eV lamp or a flame ionization detector (FID) The test procedure involves measuring approximately 30 grams from an undisturbed soil sample, placing this sub-sample in a sealed container (either a zip-lock bag or a mason far) The container was 1 will be warmed for approximately 20 minutes (in the sun), then the head-space within was tested for total organic vapor, measured in parts per million as benzene (ppmv, volume/volume) The