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MW 1 and from 22 to 32 feet bgs in UVB-MW2 The wells were sealed with a 2-3-foot layer of hydrated bentonite pellets, followed by a neat cement grout to dust below the top of the casing of ' each well Both wells were completed at the surface with locking caps and 8-inch-diameter water tight well boxes Well construction details are summarized in Table 2 and shown on the 1 well construction diagrams in Appendix A The screen interval for UVB-MW 1 was placed in the upgradient direction so that it matched the ' lower screen of the UVB well, and the screen interval for UVB-MW2 was placed in the downgradtent direction so that it matched the upper screen of the UVB well UVB-MW l will be used to monitor the groundwater entering the UVB system (influent), and UVB-MW2 will be ' used to monitor the groundwater exiting the UVB system (effluent) 3.7 WELL DEVELOPMENT ' 3.7.1 UVB Well ' The UVB well was developed from 4 to 6 December 1996 by repeated purging and surging with a submersible pump The upper screen interval was purged and surged at a pumping rate of 8 gallons per minute (gpm) for approximately 1 hour until the pH, conductivity, and temperature ' stabilized and the turbidity was less than 10 NTU Approximately 400 gallons of water was removed during purging of the upper screen on 4 December An inflatable packer was then placed between the upper and lower screens so that the lower screen interval could be developed independently On 4 December, the lower screen interval was purged and surged for approximately 4 5 hours at a pumping rate varying from 8 to 15 gpm Approximately ' 1,700 gallons of water was purged from the UVB well on 4 December 1996 Due to high turbidity readings and the presence of fine sand in the purge water, EA returned to the site on 5 and 6 December to continue purging and surging the well Approximately 10,000 gallons of ' water was generated during the development of the UVB well A description of well development procedures are provided in Appendix B, and records of well development are presented in Appendix D ' 3.7 2 UVB Monitoring Wells ' Groundwater monitoring wells UVB-MW 1 and UVB-MW2 were developed on 25 February 1996 Both wells were surged with a 2-inch surge block for approximately 5 minutes After surging, approximately 15 well casing volumes of water were pumped from the wells This ' procedure was repeated at least three times until the water was free of silt and visible turbidity Approximately 170 gallons of water was generated during the development of wells UVB-MW 1 and UVB-MW2 A description of well development procedures are provided in Appendix B, ' and the records of well development are presented in Appendix D 3.8 UVB SYSTEM START-UP AND OPERATION ' Start-up troubleshooting of the UVB system m was performed on 5 February 1997 The packer support cables were checked for tightness and twisting Air pressure in the inflatable packer was measured, and air was added as necessary to maintain 3 0 bar WP61 73942 R0I397 3 9