(A) Generally. A geotechnical report shall be prepared for every grading permit application or grading plan review unless waived by the City Engineer/Public Works Director. Each geotechnical report shalt be prepared in accordance with this section and generally accepted soil engineering practices. Each report shall include infiltration rate test results pursuant to the latest guidelines for infiltration testing, outlined in the Riverside County Flood Control and Water Conservation District Handbook for Low Impact Development Best Management Practices. Each geotechnical report shall be approved by the City Engineer/Public Works Director. The Building Official may also require a soil engineering report or additional information related to the building structure in accordance with the California Code of Regulations Title 24 (CBC). Recommendations contained in the approved reports shall be incorporated into the grading plans and shall become conditions of the grading permit.
(B) Soil engineering report. Unless waived by the City Engineer/Public Works Director, a soil engineering report shall be prepared and submitted for any grading permit application or grading plan review associated with any residential, commercial, industrial, or similar development project. The soil engineering report shalt include information and data regarding the nature, distribution, and physical and chemical properties of existing and imported soils; conclusions as to the adequacy of the site for the proposed grading; recommendations for general and corrective grading procedures; detailed information for the location of recommended stabilization fills or buttress fills; foundation and pavement design criteria; and shalt provide other recommendations as determined necessary by the City Engineer/Public Works Director.
(C) Engineering geology report. An engineering geology report shalt be prepared and submitted for any grading permit application associated with any development on a hiltside site where geologic conditions are determined by the City Engineer/Public Works Director to have a substantial effect on existing and/or future site stability. This requirement may be extended to other sites as required by the City Engineer/Public Works Director. The engineering geology report shalt include a comprehensive description of the site topography and geology including, where necessary: a geologic map; an opinion as to the adequacy of the proposed development from an engineering geologic standpoint; an opinion as to the extent known or as reasonably should be known how instability on adjacent properties may adversely affect the project; a description of the field investigation and findings; conclusions regarding the effect of geologic conditions on the proposed project; and specific recommendations for modifications to the grading plans, corrective grading, and/or special techniques and systems to facilitate a safe and stable development. The engineering geology report shalt also provide other recommendations as necessary for the project grading and development. The engineering geology report may be combined with the soil engineering report.
(D) Imported earth material.
(1) A geotechnical report must be provided for all imported earth materials to be used for grading operations, unless waived by the City Engineer/Public Works Director. The Geotechnical Engineer, Soils Engineer, or Engineering Geologist must certify the source of the material, including the previous land uses from where the fill was obtained. The City Engineer/Public Works Director may require Phase I and/or Phase II Environmental Assessments to be conducted for the imported earth material to verify that contaminants are not present in the material. The City Engineer/Public Works Director may make determinations on the requirements and scope of the Environmental Assessment.
(2) Contaminants. Imported material may not contain levels of contaminants exceeding the California Office of Environmental Health Hazard Assessment's Toxicology Criteria in California Code of Regulations, Title 22, Division 4.5, Chapter 51, Article 2, § 69021, Appendix I.
(E) Seismicity report.
(1) Applicability. Grading permit applications for sites containing earthquake-sensitive earth materials and/or sites that are located on or near potentially active or active faults are required to submit a seismicity report, including earthquake fault and liquefaction hazard studies, in accordance with the requirements of the Alquist-Priolo Earthquake Fault Zoning Act and the Seismic Hazard Mapping Act. The City Engineer/Public Works Director may require a seismicity report for any grading permit application associated with any residential, commercial, industrial, or similar development project. A seismicity report shall be required as a condition of development for all essential facilities, as defined in the California Building Code, or as determined by the City Engineer/Public Works Director, Building Official, or Community Development Director. Where required, the report shall be reviewed and approved prior to issuance of a grading permit.
(2) Content. The report shall be prepared by an engineering geologist, a geophysicist or a civil engineer with expertise in earthquake technology and its application to buildings or other civil engineering works. The scope of the report shall be commensurate with the proposed development and shall reflect the latest available and accepted technological recommendations related to seismicity. The minimum acceptable pseudo-static slope stability factor of safety shall be 1.1 and the minimum acceptable surficial stability factor of safety shall be 1.5. The seismicity report may be combined with the soil and engineering geology reports.
(3) Submit approved report. A copy of each approved geotechnical report including the mitigation measures is required to be submitted to the Seismic Hazard Mapping Program of the California Department of Conservation, California Geological Survey within 30 days of approval of the report pursuant to the Seismic Hazard Mapping Act and Alquist-Priolo Act.
(Ord. 2022-364, passed 11-16-2022)