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FIELD PROCEDURES y. Soil Boring _ ` The soil borings will be constructed using push technology drilling equipment. A boring i' approximately one and a half inches in diameter will be advanced to a depth of approximately 25 feet. Soil samples will be collected from the borings at five-foot maximum intervals with a , _ - modified California sampler equipped with clear polyethylene tubing and drill cuttings will be y_- 'described in the field using the Unified Soil Classification System(USCS). Sample tubes will M be sealed with plastic end caps to reduce volatile hydrocarbon loss. The samples will be _ screened in the field with a Photo Ionization Detector(PID)to evaluate potential hydrocarbon content. Selected samples will be placed in an ice chest containing ice, and submitted under chain-of-custody to a California-certified laboratory for analysis as previously described." —Borings not converted to monitoring wells will be sealed to the surface with a slurry of neat; 4 , cement grout containing approximately 5%bentonite. 'Monitoring Weil Construction One of the soil borings will be converted to a monitoring well. The well will be constructed using ' one-inch diameter, flush jointed, Schedule 40 PVC casing; 0.01-inch slotted casing will be used for 3 the screened interval. The screened interval will extend from to 10 to 25 feet below site grade. Number 3 Monterey sand will be placed in the well annulus as a filter pack using the tremie -. method.- The filter pack will extend from the bottom of the screened interval to approximately two ` feet over the screened interval. A two-foot thick bentonite seal will be placed in the well annulus above the filter pack. A grout seal consisting of a Portland Cement and bentonite slurry will be # poured into the well annulus above the bentonite seal. The well will be completed with a well cap and a flush-mounted,traffic-rated well cover. A proposed well diagram is shown on Plate No. 3. The wells will be constructed under the supervision of a California Registered Geologist. T Monitoring Well Development, Pur&g and Sam lin After well construction islcompleted,the water level in the new well will be measured with an electronic well sounder-and the well will be checked for free product using a clear bailer. The well will subsequently be developed using a small diameter surge bailing device. Approximately three well volumes of water will then be removed with tygon tubing equipped with a check valve until temperature,pH and conductivity readings stabilized and/or the water clears of sediment. After a minimum of 24 hours from the time of development,the water level in the well will be measured, and the water checked for visual signs of free product. Approximately three to five additional well volumes of water will then be purged using a clean, check valve system until temperature,pH,and conductivity readings stabilized and/or the water clears of sediment. The water samples will be - then collected using new polyethylene disposable bailers. Water from the tubing will be decanted - into appropriate sample containers provided by the laboratory. The sample will immediately be placed in an ice-chest with ice, along with a travel blank, and submitted under chain-of-custody to a California-certified laboratory for analysis of Total Petroleum Hydrocarbons(TPH)using EPA INK — _ WALLACE-KUHL 3 Recycled paper - - - EF ASSOCIATES INC. --?