2009-04-29_PERMIT FILE - C1982056 (6)

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2) Non-structural backfill placed around the buildings should be compacted to at least 95% of the • maximum standard Proctor density at or near the optimum moisture content in order to minimize future settlement of the fill. The backfill should be placed immediately after the braced foundation walls are able to structurally support the fill. Puddling or sluicing must be avoided. 3) The top 2 to 3 feet of soil placed within 10 feet of the foundations should be impervious in nature to minimize infiltration of surface water into the wall backfill. 4) Roof downspouts and drains should discharge well beyond the limits of all backfill. Roof overhangs, which project two to three feet beyond the foundation, should be considered if gutters are not used. 5) Plastic membranes should not be used to cover the ground surface adjacent to foundation walls. Site Grading Recommendations All of the fill materials placed at the site should be uniformly placed and compacted in 6 to 8 inch loose lifts to at least 95 percent of the maximum standard Proctor density and within -1 to +4 percent of the optimum moisture content, as determined in accordance with ASTM D-698. The fill materials placed in these areas should not contain topsoil and organic materials or other deleterious substances. The materials not suitable for use under the pads or in the embankment fills should be stockpiled for future reclamation use. Site grading should be carefully planned to provide positive surface drainage away from the structures and pavement areas. The structures and pavement areas should be placed as high as possible on the site so that positive drainage away from these structures can be provided. Surface diversion features should be provided around parking areas to prevent surface runoff from flowing across or under the paved surfaces. We recommend that any permanent, unretained cuts in the natural overburden soils not exceed a 2 (Horizontal) to 1 (Vertical) slope configuration and the permanent, unretained cuts in the bedrock materials not exceed a 1 (Horizontal) to 1 (Vertical) slope configuration. We recommend that the permanent embankment fill slopes not exceed 2 (Horizontal) to 1 (Vertical) slope configuration. The embankment fill materials should be properly benched/keyed into the hillsides exceeding a 4 (Horizontal) to 1 (Vertical) configuration In our opinion, excavation of the overburden soils and near surface bedrock materials should be possible with heavy duty conventional excavation equipment with ripper teeth. • Job Number: 08-8241 NWCC, Inc. Page 8