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Compressible materials, within areas planned to support pavement or other appurtenant <br />structures outside of the proposed building footprints, should be excavated to competent <br />material and replaced with compacted fill soils. We anticipate these removals on the site to be <br />on the order of approximately 3 feet below existing grade or 2-foot below any footings; <br />however, localized, deeper removals should be anticipated where deemed necessary by the <br />geotechnical consultant based on observations during grading. Removal bottoms should be <br />scarified to a minimum depth of 12 inches, brought to at least optimum -moisture content, and <br />recompacted. <br />Based on our site investigation groundwater was not encountered to the maximum explored <br />depth of 51.0 feet below the existing site grades and groundwater is not anticipated to be <br />encountered during site excavation. <br />From a geotechnical perspective, material that is removed may be placed as fill provided the <br />material is relatively free from rocks (greater than 6 inches in maximum dimension), organic <br />material and construction debris, is moisture -conditioned or dried (as needed) to obtain above - <br />optimum moisture content, and then recompacted prior to additional fill placement or <br />construction. <br />4.1.3 Shrinkaze/Bulkinm <br />Based on the site soils, bulking is not anticipated at the site. The preliminary estimated <br />shrinkage factors of approximately 10 percent for the alluvium may be used for consideration <br />of earthwork calculations. These are preliminary rough estimates which will vary with depth <br />of removal, stripping losses, field conditions at the time of grading, etc. In addition, handling <br />losses are not included in the estimates. <br />4.1.4 Temporary Excavation Stability <br />Due to the recommended depth of remedial removals below existing grades (approximately 5 <br />to 10 feet), the temporary stability of the excavations along the perimeter of the site needs to be <br />considered. In general, all excavations should be performed in accordance with project plans, <br />specifications, and all Occupational Safety and Health Administration (OSHA) requirements. <br />Excavations should be laid back or shored in accordance with OSHA requirements before <br />personnel or equipment are allowed to enter. Soil conditions should be mapped and frequently <br />checked by a representative of LGC to verify conditions are as anticipated. The contractor <br />shall be responsible for providing the "competent person" required by OSHA standards to <br />evaluate soil conditions. Close coordination with the geotechnical engineer should be <br />maintained to facilitate construction while providing safe excavations. Excavation safety is the <br />responsibility of the contractor. <br />Temporary excavations maybe cut vertically up to five feet. Excavations over five feet should <br />be slot -cut, shored, or cut no steeper than 1H: 1V (horizontal, H: vertical, V) slope gradient. <br />Surface water should be diverted away from the exposed cut, and not be allowed to pond on top <br />of the excavations. Temporary cuts should not be left open for an extended period of time. <br />Planned temporary conditions should be reviewed by the geotechnical consultant of record in <br />order to reduce the potential for sidewall failure. The geotechnical consultant may provide <br />recommendations for controlling the length of sidewall exposed. <br />Project i y 66n,61 18 — 829 1 3 , 2021 <br />