SITE INFORMATION AND CORRESPONDENCE

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California Environmental Protection Agency Department of Toxic Substances Control --------------------------------------------------------------------------------------------------------------------------------- 1. Earth (Workbook; page 11) --------------------------------------------------------------------------------------------------------------------------------- Description of Environmental Setting: The Site lies within the Great Valley Geomorphic province of California, in eastern portion of the Sacramento/San Joaquin Delta. The geology is characterized by Pleistocene and Recent alluvial deposits consisting of heterogeneous sequence of sands and gravels originating from active stream channels, and from silts and clays originating from over-bank and marsh depositional environments. The Site is capped with fill from a few feet deep in the northern portions to greater than 10 feet deep in the southern portions near the Stockton Ship Channel. Near surface, shallow soils are typically silts and clays with intermittent zones of permeable sand. Low permeability marsh and deltaic mud deposits underlie the silts and clays. There is also evidence of fill comprised of soil mixed with debris, such as wood, glass, and metal. Although not evident in soil boring logs, historical reference to the use of dredge spoils as fill appears in some reports. Groundwater is typically encountered at 15 to 25 feet below ground surface. Groundwater recharging the Site originates in the Stockton Ship Channel, which is impacted by contamiants from upstream urban sources (street and agricultural runoff). The chemical make up of the general groundwater in the Stockton downtown area and the Ship Channel are known to be of poor quality as cited by a California Department of Water Resources report dated as early as 1967. Ref: Treadwell & Rollo, Remedial Investigation, Volume I, North Shore Parcels, Stockton, California, 24 August 2000. Analysis of Potential Impacts: Approximately 415 cubic yards of contaminated soil will be excavation and properly disposed of with clean fill used for any backfill. Any disruption to the soil will be temporary and will likely occur when the property is being prepared for redevelopment. Excavation of the contaminated soil is scheduled to take place during a two-week period, however, the duration could be longer to accommodate any staging activities during development activities. The City of Stockton will prepare separate soils management plan that will provide specific details on how the soil will be excavated, handled, rrlanaged, transported and disposed. Dust control will be maintained during the excavation, transfer and loading of the vehicles. The project will not be exposed to risks associated with fault ruptures. The topography and surface relief features will remain essentially the same. Due to the relatively small scale of the project, and because the physical conditions of the earth will be similar before and after the project, there is no potential for significant impacts on the earth. Ref: Treadwell & Rollo, Remedial Investigation, Volume I, North Shore Parcels, Stockton, California, 24 August 2000. Treadwell & Rollo, Revised Feasibility Study, North Shore Parcels, Stockton, California, 15 November 2000 5