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riser pipe. A clean-washed, graded silicate sand will be placed around the well screen and to 1 to 2 feet above it. A transitional sand pack will be placed above that, followed by a layer of hydrated, manufactured bentonite. The transitional sand pack and bentonite layer will each be 1 to 2 feet thick. Both the screen slot width and filter pack and transition pack gradations will be selected following inspection of the log for CPT-3. A mechanically-mixed cement-bentonite slurry will be placed into the annular space between the PVC riser pipe and the inside of the conductor casing and brought to near-surface. It is expected that a higher strength cement may be placed at the top of the conductor casing, to tie together shallow soils, road subgrade,top of conductor casing, and the traffic box. Shaw will select and install materials in conjunction with a licensed C-57 contractor with low demonstrated expertise in such well constructions, and in accordance with state and county regulations and guidance. 3.6 Well Development The well will be developed by swabbing and bailing, no sooner than 36 hours after installation has been completed. Swabbing will consist of moving a vented surge block or large PVC bailer in up and down strokes, no more than three feet in length, beginning at the top of the screened +� well casing and progressing to the bottom of the well. The swabbing will be performed to draw fine sediments from the screen filter pack and into standing well water, to be removed by hand bailing. A minimum of five static well volumes of water will be removed from the well during development. The field measured parameters of pH, temperature, conductivity, and turbidity will be monitored. Development of the well is expected to be terminated when these parameters have stabilized. 3.7 Groundwater Sampling and Analysis One groundwater sample will be collected form the new well after it has been developed. The monitoring well will be purged prior to collection of a groundwater sample. A minimum of three static well casing volumes will be purged from the well using either a dedicated, disposable bailer, or a thoroughly-decontaminated pump or other system. During the purge process, pH, specific conductivity and temperature will be measured to ensure that fresh formation water is entering the wells prior to sampling. Purge water will be placed into a labeled, 55-gallon drum for on-site storage pending disposal. r� All groundwater samples will be collected from the well using a disposable bailer that is dedicated for use at that well, to prevent any potential for cross-contamination of samples. The N%� water samples will be transferred from the bailers into the appropriate laboratory supplied 60 SacDP-N.1sacDR20051PrA88018800401A5acWPParkinson.doc 3_3 9.8.05 4