Part 5 — Geotechnical Investigations and Inspections

A soil or geologic investigation report shall accompany the application in any of the following circumstances when required by the agency director:

• A. When the proposed grading includes a cut or fill exceeding 10 feet in depth at any point; however, for vehicular ways, a soil investigation shall not be required unless the grading includes a proposed cut or fill that exceeds 10 feet in depth and the slope of the natural ground exceeds 30%;

• B. When highly expansive soils are present;

• C. In areas of known or suspected geological hazards, including landslide hazards and hazards of ground failure stemming from seismically induced ground shaking.

• (Ord. 5056-B, 2000; Ord. 5407-B § 13, 2006)

Those portions of the soil or geologic investigation that constitutes "civil engineering" as defined by Section 6734 of the Business and Professions Code of the state of California shall be conducted by or under the direct supervision of a geotechnical engineer or civil engineer. Those portions of the investigation that involve the practice of "geology" as defined by Section 7802 of the Business and Professions Code of the state of California shall be conducted by an engineering geologist.

The investigations shall be based on observations and tests of the material exposed by exploratory borings or excavations and inspections made at appropriate locations. Additional studies may be necessary to evaluate soil and rock strength, the effect of moisture variation on soil, bearing capacity, compressibility, expansiveness, stability, keying, subdrainage benching and other factors. Grading factors such as moisture variability, ability to compact the material when wet, etc., should be evaluated. (Ord. 5056-B, 2000)

Any soil or geologic investigation report shall be subject to the approval of the community development resource agency who may require supplemental reports and data. Recommendations included in the reports and approved by the community development resource agency shall be incorporated in the final plans and specifications. (Ord. 5056-B, 2000; Ord. 5373-B, 2005; Ord. 5407-B, 2006)

The soil or geologic investigation report shall contain all of the following, as they may be applicable to the subject site:

• A. An index map showing the regional setting of the site;

• B. A site map which shows the topographic features of the site and locations of all soil borings

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Placer County, CA § 15.48.390

PLACER COUNTY CODE

• C. A classification of the soil types (unified soil classification), pertinent laboratory test data and consequent evaluation regarding the nature, distribution, and strength of existing soils;

• D. A description of the geology of the site and geology of the adjacent areas when pertinent to the site;

• E. A suitably scaled map and cross sections showing all identified areas of land slippage;

• F. A description of any encountered groundwater or excessive moisture conditions;

• G. A description of the soil and geological investigative techniques employed;

• H. A log for each soil boring and test excavation showing elevation at ground level and the depth of each soil or rock strata;

• I. An evaluation of the stability of pertinent natural slopes and recommendations regarding maximum cut and fill slopes of proposed work;

• J. An evaluation of settlement associated with the placement of any fill;

• K. Recommendations for grading procedures and specifications, including methods for excavation and subsequent placement of fill;

• L. Recommendations regarding surface and subsurface drainage and erosion control;

• M. Recommendations for mitigation of geologic hazards. (Ord. 5056-B, 2000)

Upon completion of rough grading work, in the event a complete record of the work is desired or necessary, the community development resource agency may require a final geotechnical report that includes, but is not necessarily limited to the following:

• A. A complete record of all field and laboratory tests including location and elevation of all field tests;

• B. A professional opinion regarding slope stability, soil bearing capacity, and any other pertinent information;

• C. Recommendations regarding foundation design, including soil bearing potential and building restrictions or setbacks from the top or toe of slopes;

• D. A declaration by the geotechnical engineer, civil engineer or engineering geologist in the format required by the community development resource agency that all work was done in substantial conformance with the recommendations contained in the soil or geologic investigation reports as approved and in accordance with the approved plans and specification.

• (Ord. 5056-B, 2000; Ord. 5373-B, 2005; Ord. 5407-B, 2006)

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Placer County, CA

BUILDING AND DEVELOPMENT

§ 15.48.410

§ 15.48.430

Where soil or geologic conditions encountered in the grading operation deviate from that anticipated in the soil and geologic investigation reports or where such conditions warrant changes to the recommendations contained in the original soil investigation, a revised soil or geologic report shall be submitted for the approval of the community development resource agency.

(Ord. 5056-B, 2000; Ord. 5373-B, 2005; Ord. 5407-B, 2006)

• A. As a condition of the permit, the community development resource agency may require the permittee to retain a private geotechnical engineer or civil engineer to directly supervise or perform continuous inspection work, and upon completion of the work to provide a written statement acknowledging that he or she has inspected the work and that in his or her professional judgment the work was performed in accordance with the approved plans and specifications. The permittee shall make his or her own contractual arrangements for such services and shall be responsible for payment of all costs. Continuous inspection by a geotechnical engineer or civil engineer shall include, but not be limited to, the following situations:

  1. During the preparation of a site for the placement of fills which exceed five feet in depth on slopes which exceed 10% and during the placing of such fills; however, for vehicular pathways, fill placement shall be continuously inspected when fills exceed 10 feet in height;

  2. During the installation of retaining walls over four feet in height, as measured from bottom of footing to top of the retained soil, or any retaining walls subject to a surcharge;

  3. During the installation of sound walls;

  4. During the installation of private vehicular bridges;

  5. During the installation of an embankment for use as a dam;

  6. During the preparation of a site for the placement of any fill which is intended to support any building or structure when the fill exceeds three feet in depth;

  7. During the installation of subsurface drainage facilities.

• B. Reports filed by the private geotechnical engineer or civil engineer regarding special inspection shall state in writing that from his or her personal knowledge the work performed during the period covered by the report has been performed in substantial accordance with the approved plans and specifications.

• C. The use of a private geotechnical engineer or civil engineer for inspections shall not preclude the community development resource agency from conducting personal inspections or from authorizing inspections by other qualified inspectors as may be necessary.

• (Ord. 5056-B, 2000; Ord. 5373-B, 2005; Ord. 5407-B, 2006; Ord. 6175-B § 1, 2022)

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Placer County, CA

PLACER COUNTY CODE

§ 15.48.430

§ 15.48.470

The permittee shall cause the work to be done in accordance with the approved plans. If during the course of construction the private geotechnical engineer or civil engineer finds that the work is not being done substantially in accordance with the approved plans and specifications, he or she shall immediately notify the person in charge of the work and the community development resource agency of the nonconformity and the corrective measures to be taken. When changes in the plans are required, he or she shall prepare or cause to be prepared such proposed changes and submit them to the community development resource agency for approval. (Ord. 5056-B, 2000; Ord. 5373-B, 2005; Ord. 5407-B, 2006)

As a condition of the report, periodic progress reports shall be rendered by the private geotechnical engineer or civil engineer as required by the community development resource agency including, but not limited to, laboratory tests, slope stability, placement of materials, retaining walls, drainage, utilities and any special permit or plan requirements. (Ord. 5056-B, 2000; Ord. 5373-B, 2005; Ord. 5407-B, 2006)

Periodic progress reports shall be rendered by permittee on specified calendar dates and at commencement and completion of major key grading and erosion and sediment control operations. The dates of operations upon which such reports are required and their content shall be as required by the community development resource agency in the permit. (Ord. 5056-B, 2000; Ord. 5373-B, 2005; Ord. 5407-B, 2006)

Permittee shall submit to the community development resource agency a record drawing of the grading plan following completion of the work.

(Ord. 5056-B, 2000; Ord. 5373-B, 2005; Ord. 5407-B, 2006)

The community development resource agency may inspect any work or require certification by private engineer of any work done under a grading permit. No permittee shall be deemed to have complied with this article unless one of the following has occurred:

• A. A final inspection approval has been issued by the community development resource agency; or

• B. Submittal of certification of completion by the civil engineer, or the geotechnical engineer of record, has been accepted by the community development resource agency; or

• C. The final inspection has been waived in writing by the community development resource agency.

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Placer County, CA

BUILDING AND DEVELOPMENT

§ 15.48.470

§ 15.48.480

The permittee shall provide adequate access to the site for inspection by the community development resource agency during the performance of all work and for a minimum period of one year after completion of the work.

If the engineer of record is changed during the grading, the work shall be stopped until the replacement has agreed in writing to accept their responsibility within the area of technical competence for approval upon completion of the work. It shall be the duty of the permittee to notify the agency director in writing of such change prior to the recommencement of such grading.

• (Ord. 5056-B, 2000; Ord. 5373-B, 2005; Ord. 5407-B § 14, 2006)

The permittee shall also be responsible for the following:

• A. Protection of Utilities. The permittee shall be responsible for the prevention of damage to any public utilities or services.

• B. Protection of Adjacent Property. The property owner is responsible for the prevention of damage to adjacent property. No person(s) shall excavate on land sufficiently close to the property line to endanger any adjoining public street, sidewalk, alley or other public or private property, or easement, without supporting and protecting such property from damage which might result.

• C. Advance Notice. The permittee shall notify the community development resource agency at least 24 hours prior to the start of work.

• D. Erosion and Sediment Control. It shall be the responsibility of the permittee to control discharge of sediment from the site to any watercourse, drainage system, or adjacent property and to protect watercourses and adjacent properties from damage by erosion, flooding or deposition which may result from the permitted grading.

• E. Hazardous Materials Control. It shall be the responsibility of the permittee to prevent discharge of hazardous materials from the site to any watercourse, drainage system, or adjacent property, and to protect watercourses and adjacent properties by hazardous materials, which may result from, permitted grading.

• (Ord. 5056-B, 2000; Ord. 5373-B, 2005; Ord. 5407-B, 2006)

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Placer County, CA