406 PECKS DR Geotech Report 2025-07-14

December 30th, 2021 G-5593 4730- Seahurst Ave, Washington 98203 Page 6 -Passive Pressure(Lateral Resistance) 350 pcf, equivalent fluid weight, for structural fill or competent undisturbed native soil - Coefficient of Friction (Friction Factor) 0.35 for structural fill or competent undisturbed native soil Drainage Water should not be allowed to stand in areas where footings, slabs, or pavements are to be constructed. Final site grades should provide drainage away from the building structure. Footing drains, consisting of a 4-inch minimum diameter, rigid perforated drain pipe, should extend around new perimeter foundations and be installed behind new basement and retaining walls, if present. Footing drains should be bedded in washed drain rock and the rock wrapped with geotextile filter fabric, such as Mirafi 140N, or equivalent, as illustrated Plate 5—Typical Footing Drain. The drain rock should extend above the base of the vertical drain mat. Roof and other drain lines should not be connected to the footing drain system. We recommend installing a sump pump system if the footing drain system cannot drain by gravity to a discharge location. Installation of clean-outs are recommended to allow periodic maintenance of the drain system. Grading and Earthwork Erosion Control Temporary erosion and sedimentation controls (TESCs), such as silt fences, should be installed down-gradient of the areas to be disturbed to prevent sediment-laden runoff from being discharged off site and effort should be made to prevent tracking of soil onto the street. Surface runoff should not be allowed to flow over the top of slopes into excavations. During wet weather, exposed soils should be covered with plastic sheeting or straw mulch. Stockpiled soils should be covered with plastic tarps. For permanent erosion control disturbed soils should be landscaped and mulched upon completion of the site work. Excavations and Slopes Excavation work for the project should not extend below a 1 H:1 V line extending from the property lines in loose to medium dense soils, in order to avoid affecting the adjacent properties. GEO Group Northwest,Inc.