IMPORTANT INFORMATION RELATED TO THE REOPENING OF THE VENTURA COUNTY GOVERNMENT CENTER (07/20/2020)
All applications and re-submittals will be made online via vcca.ventura.org or emailing the documents to PWA_LDServices@ventura.org. Please contact our division about procedures at PWA_LDServices@ventura.org or call (805) 654-3027.

Soil Report Review

The geotechnical report is a tool used to communicate the site conditions and design and construction recommendations for a project site. These types of reports are typically required for any structures such as main residences, guesthouses, additions, barns, detached accessory structures etc. Such reports are also required for most site grading, retaining walls, and hillside construction.

WHY DOES VENTURA COUNTY REQUIRE GEOTECHNICAL (SOILS) REPORT REVIEW?

The County of Ventura is over 2,200 square miles and with area of that magnitude, the geology and soil conditions can vary vastly. Like most regions of this size, the County has numerous faults, areas of expansive soils, areas with liquefaction, landslide potential and other geological natural hazards. The County of Ventura attempts, through geological/geotechnical review, to ensure that geotechnical design recommendations and plans meet minimum standards and acceptability, in order to reduce the exposure to geologic hazards and the damage resulting from them.

A geotechnical review by the County involves the thorough review of pertinent geologic and engineering reports, maps and other information to reduce the exposure of a site or structure to such hazards, consistent with accepted standards of the geotechnical profession. Additionally, the State of California requires geotechnical review within mapped seismic (earthquake) zones. The basic responsibility for design remains with the applicant’s consultants. The importance of preparing an adequate geotechnical report cannot be taken lightly. Therefore, the report should be clear, concise, and accurate. Both an adequate site investigation and a comprehensive geotechnical report are necessary to construct a safe, cost-effective project. Engineers need these reports to conduct an adequate review of geotechnical related features, e.g., earthwork and foundations.

Geotechnical Report Requirements

Geotechnical Reports must comply with the County of Ventura General Plan, Goals, Policy and Programs as well as provide the information required by the Ventura County Building Code, latest Edition. The following guidelines are provided to assist in the preparation of Geotechnical Reports for Building and Grading Permits.

  1. Purpose and Scope of Study
    1. Proposed Project Description;
    2. Site Address and Assessor Parcel Number (APN)
    3. Scope of Work: ex. Geotechnical Report, Fault Investigation,
    4. Date of site inspection and person performing inspection;
    5. Job Address: Lot/Tract Number, APN (Assessor’s Parcel Number);
    6. Signature and registration number of licensed professionals; Soils Engineer, Geologist
  2. Site Conditions
    1. Location description
    2. Site Access: How is site Accessed?
    3. Site Topography including Site Maps with scale and north arrow
      1. USGS Quad Location Map
      2. Dibblee, USGS, or CGS Regional Geologic Map
      3. California Seismic Hazards, Earthquake, Landslides and Liquefaction
    4. Site Relief, steepness and heights of slopes
    5. Site Drainage Conditions and Evidence of Erosion.
    6. Geologic Hazards; faults, landslides, liquefaction, subsidence, erosion, rockfall, etc.
    7. FEMA floodplains
    8. Existing man made features.
    9. Existing improvement performance or distress.
    10. Past site uses.
    11. Adjacent Property; present use or boundary delineation, existing structures, etc.
  3. Planned Construction Parameters
    1. Type of construction
    2. Type of foundation and floor system, including setbacks.
    3. Number of stories
    4. Estimated structural loads
    5. Distance to adjacent structures and property lines
    6. Retaining wall type and surcharge loads
    7. Swimming Pool or other structures
  4. Geotechnical Data
    1. Previous Geotechnical Data, referenced reports
    2. Field Investigation
      1. Scope of field investigation, date, methods used, sampling methods and type of sample, logs of exploration (boring/test pit, etc.), elevations of explorations, method of backfilling and future requirements.
      2. Site plan showing explorations, proposed improvements, terrain and man made features, areas of geologic hazard, access to proposed improvements, cross-sections, geologic information and structural data
      3. Data on location and method used for sample collection, both surface and subsurface.
      4. Groundwater conditions, depth encountered or depth of historical high based on research source, provide source. Must demonstrate groundwater table is greater than 5 feet to lowest below grade floor level. (Sec. 1803.5.4)
    3. Laboratory Testing:
      1. Describe the laboratory testing procedures and test results. Provide graphical laboratory test results, and reference laboratory test procedures.
        1. Soil Classification ASTM
        2. Grain Size Analysis justifying soil classification ASTM
        3. Moisture content and dry density for undisturbed samples ASTM.
        4. Expansion Index (VC Building Code)
        5. Shear Strength ASTM
        6. Consolidation ASTM
        7. Corrosivity properties; sulfide-sulfate, chlorides, pH, and Resistivity.
        8. R-value
      2. Other tests to obtain material properties.
    4. Analysis
      1. Foundation design criteria
        1. Foundation type, depth, width, bearing material, installation conditions and allowable loads, lateral pressures, coefficient of friction.
        2. Estimated settlement, total, differential and rate.
        3. For Pile Foundations:
          1. Point of Fixity or Depth to Fixity from Ground Surface
          2. Downward and Upward Capacity based on Skin Friction
          3. Requirements for Restraint from all Four Directions (Sec. 1810.3.13)
          4. Moment and Shear Diagram resulting from Lateral Loads based on Embedment Depth and Soil Type
        4. Expansive Soils
        5. Pavement Design, R-value
        6. Hydrocollapse potential.
        7. Slope Stability; cross-sections, gross (static and pseudo-static) and surficial
        8. Retaining Wall, static, seismic loads for walls over 6 feet high. (Sec. 1803.5.12)
        9. CBC Seismic Analysis for Structural Design
        10. Liquefaction
        11. In accordance with California Geological Survey, SP 117
        12. Surface Displacement due to faulting or seismically induced lateral spreading
        13. Temporary Excavation Slope Stability and Shoring System Design
        14. Surface Erosion Resistance.
        15. Geologic hazards, faulting, landsliding, rockfall, as applicable
      2. Report
        1. Conclusions
        2. Geotechnical Engineering Recommendations.
        3. Foundation Design
        4. Retaining Wall Design including dynamic loads
        5. Subdrain System Design
        6. Slabs on Grade
        7. Concrete Slabs, Pavements, Permeable Pavements.
        8. Mitigation of Geologic, Geotechnical, and Flood Hazard Risks
        9. Grading Recommendations, including transition pads or other project requirements
        10. List of References

For a printable list of the requirements of a Geotechnical Report, Click here.

Who Can Prepare a Geotechnical or Geological Report?

The preparer of a Geotechnical Report is a registered Civil Engineer or Geotechnical Engineer experienced in geotechnical engineering.  The preparer of an Engineering Geologic Report is a Certified Engineering Geologist (CEG).

Application and Documents

Public Works Questionnaire. This form will be used when applying for soils report reviews, acreage assessment fee, floodplain clearance, will serve letters, and WAL reviews.

Geotechnical Report Review Fees

Fees and Deposits are set each year by the County Board of Supervisors and can found at this location (Schedule of Fees and Deposits)

How to Apply / Process

There are 3 ways to apply for a Geotechnical Report review fee. Online at vcca.ventura.org, via email by sending the questionnaire and geotechnical report to PWA_LDServices@ventura.org, or visiting our counter to turn in the geotechnical report and questionnaire.

Once a record has been created we will email instructions for payment of the review fees. After payment we will begin the review process that typically takes 10 to 15 business days. Once the review has completed a memo will be sent out with either review comments that need to be addressed by the geotech, or an approval memo will be sent to allow you to continue with the B&S building permit process.