Soil Investigations for Data Collection in the Delta Initial Study Proposed Mitigated Negative Declaration November 2019 California Department of Water Resources 1416 Ninth Street Sacramento, CA 95814 (this page is intentionally left blank) INITIAL STUDY SOIL INVESTIGATIONS FOR DATA COLLECTION IN THE DELTA 1. Proposed Project Title Soil Investigations for Data Collection in the Delta 2. Lead Agency Name and Address California Department of Water Resources 1416 Ninth Street Sacramento, California 95814 3. Contact Person and Phone Number Katherine Marquez (916) 651-9569 4. Proposed Project Location Sacramento-San Joaquin Delta 5. Proposed Project Sponsor’s Name California Department of Water Resources 6. General Plan Designation General Plan designations in the Study Area of the Proposed Project allow a variety of uses including agriculture, outdoor recreation, wildlife habitat, public facilities, and limited areas for commercial, industrial, and rural residential development. 7. Zoning Land use zoning codes in the Study Area of the Proposed Project allow a variety of uses including agriculture, outdoor recreation, wildlife habitat, public facilities, and limited areas for commercial, industrial, and rural residential development. 8. Description of Proposed Project The primary objective of the proposed project is to determine the composition, location, and geotechnical properties of soil materials commonly found in the Delta which would inform the design, environmental analysis, and development of alternatives for a potential Delta conveyance project and contribute to DWR’s overall understanding of Delta geology. 9. Surrounding Land Uses and Setting Surrounding land uses in the Study Area of the Proposed Project include a Soil Investigations for Data Collection in the Delta Initial Study/Proposed Mitigated Negative Declaration i variety of uses including agriculture, outdoor recreation, wildlife habitat, public facilities, and limited areas for commercial, industrial, and rural residential development. 10. Other Public Agencies Whose Approval is California Department of Fish and Required Wildlife (CDFW), US Army Corps of Engineers (USACE), State Office of Historic Preservation, National Historic Preservation Act, US Fish and Wildlife Service (USFWS) and National Marine Fisheries Service (NMFS), State Water Resources Control Board (SWB), and State Lands Commission (SLC). 11. Have California Native American tribes Yes, consultation is on-going and the traditionally and culturally affiliated with the consultation process is described in Proposed Project area requested consultation more detail in the Tribal Cultural pursuant to Public Resources Code section Resources section of the Initial Study. 21080.3.1? If so, is there a plan for consultation that includes, for example, the determination of significance of impacts to tribal cultural resources, procedures regarding confidentiality, etc.? MITIGATED NEGATIVE DECLARATION PROPOSED PROJECT: Soil Investigations for Data Collection in the Delta LEAD AGENCY: California Department of Water Resources PROPOSED PROJECT LOCATION: The Proposed Project Study Area is located within the legal Delta in Alameda, Contra Costa, Sacramento, Solano, San Joaquin, and Yolo Counties. PROPOSED PROJECT DESCRIPTION: The Department of Water Resources (DWR) plans to conduct soil investigations for the purposes of measuring physical properties of the soils, location of the groundwater table, and other typical geologic and geotechnical parameters that will be used to inform and evaluate alternatives, consistent with Executive Order N-10-19, for a proposed single tunnel Delta conveyance (requiring a separate CEQA process) consistent with Governor Newsom’s new approach to modernize Delta water conveyance. The primary objective of the proposed soil investigation is to determine the composition, location, and geotechnical properties of soil materials, which are anticipated to be sand, silt, Soil Investigations for Data Collection in the Delta Initial Study/Proposed Mitigated Negative Declaration ii clay and peat soils that are commonly found in the Delta. The planned work includes overwater and land-based soil borings, cone penetration tests (CPTs), and geophysical surveys. This testing is necessary because there is a lack of geotechnical data at relevant depths, available to the Department of Water Resources in the Study Area. The Study Area includes a portion of the Sacramento-San Joaquin River Delta, encompassing the area from south of the City of West Sacramento to just north of Bethany Reservoir, and stretches from east of Interstate 5 to west of State Route 160 (River Road). The landscape within the Study Area includes a variety of land-uses including agriculture, parks and open space, urban and rural residential neighborhoods, commercial development, and scenic roadways and waterways. ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED: The environmental factors checked below would be potentially affected by this Proposed Project, involving at least one impact that is a “Potentially Significant Impact” as indicated by the checklist on the following pages: ENVIRONMENTAL CHECKLIST Aesthetics Agricultural and Forestry Air Quality X Biological Resources X Cultural Resources Energy Geology Soils X Greenhouse Gas Emissions X Hazards & Hazardous Materials Hydrology/ Water Quality Land Use/ Planning Mineral Resources Noise Population/ Housing Public Services Recreation Transportation X Tribal Cultural Resources Utilities/ Service Systems X Wildfire X Mandatory Findings of Significance DETERMINATION: On the basis of the following initial evaluation, I find that although the Proposed Project could have a significant effect on the environment, there will not be a significant effect in this case because revisions in the project have been made that mitigate the potential impacts to a level that is less than significant. A MITIGATED NEGATIVE DECLARATION will be prepared. MITIGATION MEASURES: The following mitigation measures will be implemented as part of the Proposed Project to avoid, minimize, rectify, reduce or eliminate, or compensate for potentially significant environmental impacts. Implementation of these mitigation measures would reduce the potentially significant environmental impacts of the Proposed Project to less- than-significant levels: Soil Investigations for Data Collection in the Delta Initial Study/Proposed Mitigated Negative Declaration iii MM AES-1: a. Each Impact Area will be returned to as close to pre-activity conditions as possible. b. No building structures will be removed or disturbed. Soil investigation activities will occur at a distance greater than 100 feet from residences and small business operations. If fencing needs to be removed for access, it would be replaced in kind after the work is completed. c. No trees or vines will be removed during exploration activities; and only minor disturbances to vegetation would occur during mobilization of equipment. This minor disturbance may consist of mowing, removal of a few tree limbs, or trimming of bushes for site access. However, if access requires removal of any vegetation, the landowner would be consulted first to minimize the impact to both vegetation and the landowner. MM AES-2: a. Navigational lighting will be used as needed for overwater work, but will meet the standards required for waterway safety, and will not increase the existing ambient lighting of the area in a substantial way. Any lighting used on barges or drill ships will not exceed the standards of brightness for standard navigational safety requirements. b. All work will occur between sunrise and sunset. MM AGR-1: Any proposed soil investigation activities that occur on agricultural lands will be grouted in accordance with ASTM standards to five feet below the surface. The final five feet of topsoil will be replaced to return the Impact Area to as close to pre-activity conditions as possible. MM AIR-1: a. Water all exposed surfaces two times daily. Exposed surfaces include, but are not limited to soil piles, graded areas, unpaved parking areas, staging areas, and access roads. b. Cover or maintain at least six feet of free board space on haul trucks transporting soil, sand, or other loose material on the site. Any haul trucks that would be traveling along freeways or major roadways will be covered. c. All operations shall limit or expeditiously remove the accumulation of mud or dirt from adjacent public streets at the end of each workday. Use wet power vacuum street sweepers to remove any visible track out mud or dirt onto adjacent public roads as needed. Use of dry power sweeping and blower devices is prohibited. Soil Investigations for Data Collection in the Delta Initial Study/Proposed Mitigated Negative Declaration iv d. Limit vehicle speeds on unpaved roads to 15 miles per hour (mph). MM BIO-1: a. All litter, debris, unused materials, rubbish, supplies, or other material will be appropriately stored in closed containers until it can be removed from project sites and deposited at an appropriate disposal or storage site. All trash that is brought to a project site during soil investigation activities (e.g., plastic water bottles, plastic lunch bags, cigarettes) shall be removed from the site daily. b. All on-land soil investigation Impact Areas will be located outside of wetlands as defined in the Corps of Engineers Wetlands Delineation Manual (USACE 1987). c. Over-water sites will be located within portions of navigable channels or sloughs that generally do not provide appropriate