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t KEI-P88-1013 .R4 October 27 , 1994 Page 7 Well Standards (per Bulletin 74-90) The subsurface materials penetrated and details of the construction of the wells are described in the attached Boring Logs and Well Construction Diagrams, respectively. The two wells (MW14 and MW15) were each drilled and completed to a total depth of 69 feet below grade. Ground water was encountered at a depth of 61 feet below grade during drilling. Soil samples were collected for laboratory analysis and for lithologic logging purposes at a maximum spacing of 5 foot intervals, at significant changes in lithology, at obvious areas of contamination, and at or within the soil/ground water interface, beginning at a depth of approximately 5 feet below grade and continuing until ground water was encountered. Soil sampling conducted below the ground water table was for lithologic logging purposes only. The undisturbed soil samples were collected by driving a California-modified split- spoon sampler (lined with brass liners) ahead of the drilling augers. The two-inch diameter brass liners holding the samples were then sealed with aluminum foil , plastic caps and tape, labeled, and stored in a cooler, on ice, until delivery to a state- certified laboratory. Each new well casing was installed with a watertight cap and padlock. A round, watertight, flush-mounted well cover was cemented in place over each new well casing. The surface of each new well cover and the top of each new well casing were surveyed by Kier & Wright of Pleasanton, California, to Mean Sea Level (MSL) and to a vertical accuracy of 0 . 01 foot. The new wells were developed on July 18 and 19 , 1994 . Prior to development, the wells were checked for the depth to the water table (using an electronic sounder) and the presence of free product (using an interface probe or paste tape) . No free product was noted in either of the new wells. After recording the monitoring data, the two new wells were each purged (using a submersible pump) of 110 gallons of water until the evacuated water was clear and free of visible suspended sediment. All of the Unocal wells, including the newly installed wells MW14 and MW15, were monitored and sampled on September 14 , 1994 , by MPDS Services, inc. , of Concord, California . The monitoring and well development data for the Unocal wells are summarized in Table 1, and the field parameter data are summarized in Table 2 .