SITE INFORMATION AND CORRESPONDENCE

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I ,%ant Bys BASELINE; 510 420 1707; NOV-9-99 16:27; Page 16,`29 Cm' )undwater wells identified within approximately one-half mile of the Weber Block property included-. three wells owned by the California Water Service Company installed in 1.909, or from the 1950s to 1960s; these wells are reportedly used for domesticimunicipal purposes. The depth of these wells ranged from 450 to 875 feet bgs, with a surface sanitary seal installed in the wells ftom — ? ground surface to,242 to 282 feet bgs. Another well was indicated as privately owned and used for domestic purposes. This wc11 was indicated as installed in 1951 to a depth 170 feet bgs, with a sanitary surface seal to 76 feet bgs (inferred). The depth to groundwater, as encountered during drilling, was not available for any of these wells (see Appendix F). Uroundwater wells located approximately one-half to one mile from the site were identifiedas being Used for domestic, municipal, irrigation, unknown uses (possibly environmental monitoring), or destroyed.Additional wells were used forsupplying water for air conditioning systems.These wells ranged in depth from 93 to 833 feet bgs (see Appendix F). No information regarding the direction and velocity of flow within the water-bearing zones was available for any of the wells surveyed..In addition,no information was available about the number of service connections and population serviced for wells identified as municipal.and/or domestic wells in the survey. Surface Water Background The Stockton Deep Water Channel(Channel)is a dead-end slough that extends from the San Joaquin River to downtown Stockton. It splits into two arms-- McLeod Lake,which trends to the northeast, .and the Stockton Yacht Harbor,which extends along Weber Street.The peninsula between these two impoundments is called Weber Point(Black & Veatch, 3999). The Channel terminates under the parking structure located at the site.The Channel water is located approximately 9.5 to 11.5 feet below the parking structure (Kleinfelder, 1999). The Channel is relatively shallow at its terminus at the project site. The mud level on the bottom of the Channel was encountered approximately 1 I to 12 feet below the water line(Mcinfelder, 1999).'No other surface water bodies, marsh lands, wetlands, or wildlife habitats are located near the project site, which is in an urban area. Direct access to the surface water at the site is prevented by a parking structure on piles located over the Channel, although. access to the site via the Channel can be made by boat through 7 a small opening under the Center Street Bridge. Storm water drainage grates are located throughout the paved parking area and drain to the Channel. Storm water around the site is diverted to the public storm water mains and is discharged to the Channel (Wedington, 1999). A large urban storm drain that collects surface water runoff discharges along the eastern portion of the Channel. Soil and groundwater contaminants from the site are generally prevented from contact with the Channel by paving of the site and seawalls located on either side of the Channel within theproject area.,although some cracking of the seawall was observed(Siegfried Engineering, 1996). The Chumel is used for recreational opportunities, including fishing and boating. Swimming is not permitted in the Channel;signs are posted in the area indicating"no swinuning." Additional signs 97369Ak.pra.wpd-t Ii9i99 10