12728 19TH AVE SE BASE FILE Geotech Report 2025-07-29

1 IMay 28, 2007 Proposed Office Building ' L&A Job No. 7A053 Page 16 basins installed in the paved areas. Stormwater thus collected should be tightlined to discharge into a storm sewer or a suitable stormwater disposal facility 1 Building Footing Drains A subdrain should be installed around the perimeter footings of the proposed office building to minimize accumulation of groundwater under the building. The subdrain should consist of a 4- inch-minimum-diameter, perforated, rigid, drain pipe, laid a few inches below the bottom of perimeter footings. The trench and the drain line should have a sufficient.gradient (0.5% minimum) to generate flow by gravity. The drain line should be enclosed in washed gravel completely wrapped in non-woven filter fabric to within about 12 inches of finish grade. The remaining trenches may be backfilled with on-site impervious soils. Water collected by the perimeter footing subdrain should be tightlined, separately from the roof and surface stormwater drain systems,to discharge into a storm sewer or a suitable stormwater disposal facility. Cleanouts Sufficient number of cleanouts at strategic locations should be provided for the underground drain line systems. The underground drain line systems should be maintained periodically to prevent clogging. LIMITATIONS This report has been prepared for the specific application on to the subject project for the exclusive use by Builders Investing Group and their clients, associates, consultants and contractors. We recommend that this re in its entirety, be included in the project contract documents for the information of the prospective contractors for their estimating and bidding purposes and for compliance with the recommendations in this report during construction. The conclusions and interpretations in this report, however, should not be construed as a warranty of the subsurface LIU & ASSOCIATES, INC. p