1707 SCENIC DR SNO CO PUD Geotech Report 2022-10-25

e Revegetating or mulching denuded areas. ■ Directing runoff awayfrom denuded areas. ■ Reducing the length and steepness of slopes with exposed soiis. ■ Decreasing runoff velocities. ■ Preparing drainage ways and outlets to handle concentrated or increased runoff. ■ Confining sediment to the project site. � Inspecting and maintaining control measures frequently. In addition, we recommend that sloped surfaces in exposed or disturbed soil be restored so that surface runoff does not become channeled. Some sloughing and raveling of slopes with exposed or disturbed soil should be expected. Temporary erosion protection should be used and maintained in areas with exposed or disturbed soils to help reduce erosion and reduce transport of sediment to adjacent areas and receiving waters. As temporary erosion protection, we recommend the use of straw, jute matting, heavy plastic sheeting or other forms of ground cover on areas disturbed by construction. Permanent erosion protection should be provided by establishing vegetation by hydroseeding or landscape planting. Until the permanent erosion protection is established and the site is stabilized, site monitoring should be perFormed by qualified personnel to evaluate the effectiveness of the erosion control measures and to repair and/or modify them as appropriate. Provisions for modifications to the erosion control system based on monitoring observations should be included in the erosion and sedimentation control plan. Foundatioo� Design - Control �uilding General We recommend that the foundation for the planned control building be supported on conventional spread footings bearing on structural fill extending down to medium dense to dense glacial soils as described in the Subgrade Preparation section of the report. Removal of approximately 5 to 9 feet of existing fill should be anticipated below the control building. The existing fill should be removed and replaced beyond the perimeter of the building by a horizontal distance equal to the depth of the excavation. Allowable Bearing Pressure Foundations bearing on competent undisturbed glacial soils or on properly compacted structural fill extending down to undisturbed glacial soils may be designed using an allowable soil bearing pressure of 3,000 psf for isolated spread footings and continuous footings supported as described above. The allowable soil bearing value applies to the total of dead and long-term live loads and may be increased by up to one-third for wind or seismic loads. If existing fill or unsuitable native soil is observed at the foundation bearing elevation, we recommend that the contractor remove the material and backfill with structural fill consisting of imported gravel borrow. GEOENGINEER� October24,2014 Page 12 Fle No.0482-027-02