ARCHIVED REPORTS_FEASIBILITY STUDY AND CORRECTIVE ACTION PLAN

Home Browse Search

that hydraulic conductivities range from 1 to 3 feet per day within shallow groundwater, but this location contains more sandy strata than most other portions of the facility. 2.3.4 GROUNDWATER QUALITY ASSESSMENT The site resides within the San Joaquin River Basin. The Central Valley Water Board's September 1, 1998 Water Quality Control Plan (Basin Plan) for the Sacramento River and San Joaquin River Basins states,in section II-2.00: Unless otherwise designated by the Regional Water Board, all ground waters in the region are considered as suitable or potentially suitable, at a minimum,for municipal or domestic water supply (MUN), agricultural supply (AGR), industrial service supply (IND),and industrial process supply (PRO). In section III-10.00,the Basin Plan states: Ground waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. At a minimum, ground waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels (MCLS) specified in Title 22 of the California Code of Regulations. The Basin Plan does not require improvement over naturally occurring background concentrations. The Basin Plan also states that the Central Valley Water Board can make exceptions to the beneficial use designation of MUN based on technical and economic feasibility. As previously discussed, the subject site is located on Rough and Ready Island along Navy Drive in Stockton, California. The former U.S. Naval Reservation occupied three-quarters of the island and borders the western side of the site. The former Tosco Bulk Terminal is located east of the facility. The eastern portion of the island is bordered by the San Joaquin River on the north and Burns Cutoff on the south. This section of the San Joaquin River channel is used for access to the Port of Stockton, located one mile to the east of the site. Historical reports from previous consultants state that the San Joaquin River acts as a source of recharge to groundwater beneath the site and saltwater infiltration from the Stockton Deep Water Channel has been observed in the shallow groundwater beneath the site. Given the location of this site, the historical land use of Rough and Ready island, the saltwater infiltration to groundwater, and the relatively low sustained yield in low-permeability strata, it is highly unlikely that groundwater 241729(33) 3 CONESTOGA-ROVERS&ASSOCIATES