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Field Practices and Procedures Page 4 A monitoring well is typically cased with threaded, factory-perforated and blank Schedule 40 PVC. The perforated interval consists of slotted casing, generally with 0.01 or 0.02 inch-wide by 1.5-inch-long slots, with 42 slots per foot. The screened sections of casing are factory machine slotted and will be installed approximately 5 feet above and 10 feet below first-encountered water Ievel. The screened interval will allow for seasonal fluctuation in water level and for monitoring floating product. A threaded or slip PVC cap is secured to the bottom of the casing. The slip cap can be secured with stainless steel screws or friction; no solvents or cements are used. Centering devices may be fastened to the casing to ensure even distribution of filter material and grout within the borehole annulus. The well casing is thoroughly washed and/or steam cleaned, or may be purchased as pre-cleaned, prior to completion. A filter pack of graded sand will be placed in the annular space between the PVC casing and the borehole wall. Sand will be added to the borehole through the hollow stem of the augers to provide a uniform filter pack around the casing and to stabilize the borehole. The sand pack will be placed to a maximum of 2 feet above the screens, followed by a minimum 1-foot seal consisting of bentonite pellets. Cement grout containing 5 percent bentonite or concrete will be placed above the bentonite seal to the ground surface. A concrete traffic-rated vault box will be installed over the monitoring well(s). A watertight locking cap will be installed over the top of the well casing. Reference elevations for each monitoring well will be surveyed when more than two wells will be located on site. Monitoring well elevations will be surveyed by a California licensed surveyor to the nearest 0.01-foot relative to mean sea level (MSL). Horizontal coordinates of the wells will be measured at the same time. Exploratory boring logs and well construction details will be prepared for the final written report. Cone Penetrometer Tool (CPT) Testing The CPT method consists of advancing a cone-tipped cylindrical probe (1.7 inches in diameter) into the ground while simultaneously measuring the resistance to penetration. The CPT method determines soil lithology by comparing the force (cone bearing pressure) required to advance the probe (Qt) to the friction ratio (Rf) (RF equals sleeve friction [Fs] divided by the probe tip load, times the penetration pore pressure [Ud]). Computer generated CPT logs will be plotted in the field, providing the field representative a graphical log of subsurface soil lithology. A CPT test data report, which will include logs of all CPT data, graphical geologic logs, and additional information on the CPT technique, will be submitted with the final report. CPT testing will be performed in accordance with American Society of Testing and Materials (ASTM) Method D3441. The cone testing will be performed inside of a grout collar installed at the ground surface. The grout collar will allow the CPT contractor to backfill the boring as the steel rods are M:1Field Practiceffield P and P with CPT for Joes-revised 07-2004 by SJC.doc