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i onitoring Well Installation Work Plan Raymond investment Corporation August 11,2064 Page 3 Soil samples will be collected from the drill cuttings for the purpose of characterizing the cuttings for disposal. All down-hole drilling equipment will be steam-cleaned prior to use. The drill cuttings and steam cleaning effluent will be placed in DOT-approved 55-gallon drums, sealed, labeled, and left on site. Disposal of hazardous materials, if any,will be.the responsibility of the property owner. The monitoring well borings will be drilled to a depth of approximately 10 feet below the water table. It is anticipated that groundwater will be first encountered.at approximately 40 feet bgs:-The monitoring wells will be constructed with 15 feet of two-'inch outside diameter, Schedule 40, flush-threaded, ` machine-slotted PVC screen (0.020-inch slot size). The screen will extend from a depth of approximately ten feet below the water table to five feet above the water table. A flush-threaded PVC bottom cap will be placed at the bottom of the screen section in each well. Blank PVC casing will be installed above the i screens to the ground surface. A filter pack of#3 Monterey sand will be placed in the annular space to approximately two feet above the screens while the augers are in place. The depth of the sand in the annulus of the well will be monitored with a weighted tape measure while the sand is being placed and the augers are.being gradually retracted to avoid bridging. To form a protective seal, approximately two feet of bentonite chips will be installed above the sand in the wells. The bentonite chips will be installed as the augers are retracted. The bentonite will be hydrated using potable water. A surface seal of neat cement will be tremied into the annulus of the wells and will extend from the bentonite to the ground surface. ' The monitoring wells will be completed with locking traffic boxes installed flush with the ground surface. Details of the well construction will be noted on the geologic logs, including the depth intervals of the screen, sand pack, and seals. 3.3 MONITORING WELL SURVEYING,DEVELOPMENT,AND SAMPLING Following installation of the monitoring wells, the wells will be surveyed to determine the location and elevation of the well collars in order to comply with AB2886 (Water Code sections 13195 -- 13198). The well collars will be surveyed with a vertical accuracy of 0.01 foot to a NAVD 88 or NGVD 29 datum, and with a horizontal accuracy of 0.03 foot to a NAD 83 datum. The measuring points for water-level measurement will be marked on the well collars. Well survey data will be submitted in electronic deliverable format(EDF) to the State Water Resources Control Board UST site database (GeoTracker). At least 48 hours following construction, the monitoring wells will be developed by surging and bailing the groundwater in the wells until the discharge water is relatively free of sediment (clear to the unaided eye). The monitoring wells will be purged until the temperature, electrical conductivity, and pH of the water have stabilized. All well-development equipment will be cleaned prior to use by washing in a solution of laboratory-grade, non-phosphate detergent and deionized water, and double rinsing with deionized water. The purge water discharged from the wells during development will be containerized in 55-gallon drums, sealed, labeled, and left on site to await disposal pending results of laboratory analyses. Groundwater samples will be collected at least 48 hours following development of the monitoring wells. Prior to sample collection, the static water level in each well will be measured to the nearest 0.01-foot with a battery-operated, water level meter. A disposable bailer will be lowered into each well to check for floating product, petroleum odors, and/or sheen. If floating product is encountered, the thickness of the product will be measured, but no laboratory samples will be collected. The monitoring wells will be purged using'a clean, disposable bailer until the temperature, electrical conductivity, and pH of the water C/ have stabilized. At least three casing volumes of water will be purged from the monitoring wells. The a CONDOR IL