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The bottom of the well shall be comprised of a 1-foot solid casing sump, sealed with either a flush-threaded or a slip-PVC cap (if a slip-cap is utilized it shall be secured with threaded stainless steel screws). The sump shall be followed by 10 feet of 0.010-inch factory cut slotted well screen (corresponding to a well screen 1 interval of approximately 13 to 23 feet below land surface). The annular spacing between the well casing and formation shall be filled with clean No. 3 sand to a depth of about 1 foot above the 10-feet screen (corresponding to a depth to the ' top of the sand pack of about 12 feet below land surface). Filter pack depth shall be checked, and the volume of filter pack material considered for verifying that no bridging of filter-pack materials occurred. The remaining 12-feet of annular space ' shall be filled with 2 feet of bentonite chips placed on top of the sand, followed by a minimum of 10 feet of cement grout installed as a sanitary seal in the space above the bentonite to land surface. ' The top of the well-casing will be sealed with a removable plug that provides a means to secure and lock the well. Monitoring wells located in agricultural fields ' will extend at least 2 feet above land surface so as to be readily discernable during agricultural operations. The casing and plug will be enclosed in a locking monument style hinged well cover set in concrete. Permanent protective barriers or the equivalent shall be installed surrounding the monitoring well. Monitoring wells located in residential or park areas shall be set below grade, and the casing and plug shall be enclosed in a flush mounted traffic rated vault box with lid. The ' vault boxes shall be water tight and set so that drainage is away from the vault. D. Well Development ' The driller shall develop the wells using surging, bailing, and pumping techniques. Each well shall be gently surged during sand-pack installation, followed by bailing (i.e., surging will occur after the sand is poured into the annulus between the casing and borehole wall, but prior to the installation of the transitional and sanitary seals). A pump will be utilized to further develop the ' wells no less than 12 hours after sanitary seal placement, per SJCEHD Well Standards. Well development shall continue until the flowing water is visually clear (1.5 hour per well minimum development time); the volume of purge water ' shall be recorded on a standard well development form (see Appendix A for an example well development form). ' For wells located in disposal fields and pond areas, the development water and rinseate can be spread adjacent to the well construction site. In developed areas, where surroundings are comprised of streets, sidewalks, and landscaping, the development water and rinseate shall be discharged to a temporary storage ' tank and later disposed by spreading across the nearest agricultural disposal field. - 7 -