CALIFORNIA ENVIRONMENTAL QUALITY ACT INITIAL STUDY CHECKLIST FORM CITY OF PASO ROBLES PUBLIC AND AGENCY REVIEW PERIOD: 8/27/18 – 9/25/18 1. PROJECT TITLE: Main West Water Tank Replacement 2. LEAD AGENCY: City of Paso Robles 1000 Springs Street, Paso Robles CA 93446 Contact: David Foote (consultant) Phone: (805) 781-9800 Email: [email protected] 3. PROJECT LOCATION: The property is bounded by West 19th Street, Locust Street and West 21th Street 4. GENERAL PLAN DESIGNATION: Public Facility 5. ZONING: Public Facility 6. PROJECT DESCRIPTION: The project is located at West 19th Street on the site of the existing city water tank. The overall site is comprised of four parcels: APN’s 008-206-001, 008-206-002, 008-204-001 and 008- 202-002. The purpose of the project to be undertaken by the City is to construct a new water storage tank intended to replace the existing 21st Street Reservoir. The existing 4 million-gallon (MG) reservoir has reached the end of its useful life and is to be replaced with a new single 4 MG partially buried pre-stressed concrete tank on the site of the existing reservoir. The project also includes a temporary reservoir access road from 19th Street, site drainage, piping, controls, and other appurtenances. The Preliminary Design Report prepared by Water Systems Consulting, Inc. contains detailed project information and technical studies referenced in this Initial Study and is available at the City address above for review. 1 Site Access Site access is expected to remain the same. No work is expected to occur on the northern access road. A temporary construction access road may be installed to the south to construct the utility corridor and will be re-graded with erosion controls post-construction. Construction Materials and Seismic Considerations The materials of construction for the proposed reservoir will include reinforced concrete foundations, columns and roof slab. The perimeter ring wall will consist of a cast-in-place concrete wall prestressed by post-tensioned high-strength steel strand. The structural design of the Main West Tank will be based upon current engineering standards including the lateral seismic loads and hoop stresses created by static and dynamic water pressure according to the 2016 California Building Code, all other applicable codes, and geotechnical criteria relative to foundation materials and site-specific seismic data. The seismic design criteria will be based upon the project Site location in seismic Zone 4. The data developed by the geotechnical engineer establishes site ground accelerations based upon native subgrade formations. This project-specific seismic data will also be used for the estimate of hydrodynamic forces on the reservoir perimeter wall associated with seismic ground motions. Site surfacing An aggregate base gravel area will be constructed around the tank to facilitate operations and maintenance access to the tank as well as provide a surface for draining storm watershed from the tank. The asphalt paved area will provide a necessary semi-impermeable surface for directing storm water flow to a series of collection points which will converge within the drainage manhole on the eastern side of the tank. On the northeast, east, and southeast sides of the tank the asphalt area will be a minimum 15-foot offset from the outside edge of the tank. On the western side of the tank the gravel area will extend roughly to the edge of the hill providing a large laydown area for future maintenance equipment, vehicles, or materials. Off-site Improvements A new 18-inch water pipeline will be constructed in 19th Street to provide a robust new connection to the existing West Main Zone distribution system. This new pipeline will be constructed and will connect to the existing Main West Zone at the following three locations: • 19th Street and Locust Street intersection (existing 6-inch); • 19th Street and Chestnut Street intersection (existing 10-inch); and • 19th Street and Olive Street intersection (existing 4-inch to be upgraded to 10- inch per City of Paso Robles Water System Master Plan ). • A new 8-inch water pipeline will be constructed from the tee connection at the 19th Street and Locust Street intersection.). Drainage, Water Quality and Compliance with Post-Construction Requirements The Site will be required to meet applicable and appropriate requirements to reduce and/or attenuate runoff and minimize off site flow from the following entities: California Regional Water Quality Control Board for the Central Coast Region (Water Board) Post-Construction Requirements, City of Paso Robles, and County of San Luis Obispo (County). The project design will remove the existing tank structure and replace it with a tank with substantially less surface area footprint on the site. By reducing the overall impervious area the project is not subject to the Post-Construction Requirements of the Water Board. WSC demonstrates compliance with the General Permit in Attachment A of the Drainage TM 2 (Appendix A) contained in the Preliminary Design Report referenced above. Stormwater from the impervious areas (tank roof) will be collected into a main offsite drain which will be deposited to a swale at the bottom of the property. Run-off volumes will not exceed current conditions. Ground disturbance will be re-vegetated with a seed mix comprised of fast growing California native grasses combined with a range of native herbaceous plants such as buckwheat and Deer Weed. Seeded areas will not be irrigated. Construction Duration It is assumed the tanks and access road could be completed within 260 working days of NTP with the project ending in August 2019. This project would be completed over the winter season between 2018 and 2019 and the schedule does not include delays due to poor weather conditions. Maps, Figures and Attachments The Location Map and Site Plan are shown on Figures 1 and 2 attached at the end of the IS. The referenced Visual Simulations, Biological Assessment and Phase 1 Archaeological Surface Survey are attached to the IS. 7. SURROUNDING LAND USES AND SETTING: The entire property (17.9 acres) is composed of an east-west trending ridge with north and south facing slopes. A majority of the land is undeveloped Oak savannah (15.9 acres) consisting of annual grasses and oak trees. The smaller developed reservoir site (Site) is cut into the east- west trending ridge at roughly the highest point of the property and is enclosed with a chain link fence with the Site comprised of the existing reservoir with a surrounding access road. The Site defined by the current fence line is between 921 and 923 feet (ft) above mean sea level (msl) and is approximately 1.6 acres. Roughly half of the Site is comprised of the footprint of the existing reservoir. The remaining area is graded and exposed layers of artificial fill that were placed in the grading for the existing reservoir. The fill appears to be derived from the onsite Paso Robles Formation during the previous site development. A paved access road to the north of the Site from 21st Street also accounts for about 0.4 acres of the larger property. Surrounding land uses: West: City limit line, unincorporated rural lands North: Residential single family (RSF1 and RSF4) East: Residential single family (RSF4) South: Residential single family (RSF4) 8. OTHER PUBLIC AGENCIES WHOSE APPROVAL IS REQUIRED (e.g., PERMITS, FINANCING APPROVAL OR PARTICIPATION AGREEMENT): None identified 3 ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED: The environmental factors checked below would be potentially affected by this project, involving at least one impact that is a "Potentially Significant Impact" as indicated by the checklist on the following pages. Aesthetics Agriculture and Forestry Air Quality Resources Biological Resources Cultural Resources Geology /Soils Greenhouse Gas Hazards & Hazardous Hydrology / Water Emissions Materials Quality Land Use / Planning Mineral Resources Noise Population / Housing Public Services Recreation Transportation/Traffic Utilities / Service Systems Mandatory Findings of Significance DETERMINATION: (To be completed by the Lead Agency) On the basis of this initial evaluation: I find that the proposed project COULD NOT have a significant effect on the environment, and a NEGATIVE DECLARATION will be prepared. 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 by or agreed to by the project proponent. A MITIGATED NEGATIVE DECLARATION will be prepared. I find that the proposed project MAY have a significant effect on the environment, and an ENVIRONMENTAL IMPACT REPORT is required. I find that the proposed project MAY have a "potentially significant impact" or "potentially significant unless mitigated" impact on the environment, but at least one effect 1) has been adequately analyzed in an earlier document pursuant to applicable legal standards, and 2) has been addressed by mitigation measures based on the earlier analysis as described on attached sheets. An ENVIRONMENTAL IMPACT REPORT is required, but it must analyze only the effects that remain to be addressed. I find that although the proposed project could have a significant effect on the environment, because all potentially significant effects (a) have been analyzed adequately in an earlier EIR or NEGATIVE DECLARATION pursuant to applicable standards, and (b) have been avoided or mitigated pursuant to that earlier EIR or NEGATIVE DECLARATION, including revisions or mitigation measures that are imposed upon the proposed project, nothing further is required. August 10, 2018 Date David Foote, Firma Consultants Signature: 4 EVALUATION OF ENVIRONMENTAL IMPACTS: 1. A brief explanation is required for all answers except “No Impact” answers that are adequately supported by the information sources a lead agency cites in the parentheses following each question. A “No Impact” answer is adequately supported if the referenced information sources show that the impact simply does not apply to projects like the one involved (e.g., the project falls outside a fault rupture zone).