2825 COLBY AVE COLBY CENTER Geotech Report 2018-01-02 MF Import

GEOTECHNICAL ENGINEERING STUDY Mr. Arthur Skotdal —� c/o Dykeman Architects E-6225 July 27, 1993 Page 11 —. Site Drainage No groundwater seepage was encounter during completion of Boring B-1. Therefore, we — do not anticipate that groundwater will impact excavation and construction. However, some minor seepage may be exposed on the cut slope where sand lenses are encountered. Additionally, if the proposed excavation will cut across utility lines bedded � fn gravel, significant seep�ge may be conducted into the excavation from off site groundwater sources which may be flowing through the bedding. -� During construction the excavated site must be graded such that surface water is directed , � off the site. Water must not be ailowed to coilect in the building area. Loose surfaces should be sealed at night by compacting the surface to reduce the potential for moisture � infiltration into the soils. Final site grades must aliow for drainage away from the building. We suggest the ground be sloped at a gradient of three percent for a distance of at least five feet away from the building. IThe building should be provided with a perimeter footing drain system beneath the lower , level slab. The perimeter footing drain could be drained by a system of sumps, or if � grades altow, directing the water to existing storm drains. Footing drains should be ' installed around the perimeter of the building just below the bottom of the footing with a gradient sufficient to initiate flow. A typical detail is provided on Plate 4. � ;� — The appropriate locations of subsurface drains, if needed, should be esta6lished during , __I grading operations by ECI's representative at which time the seepage areas, if present, 4 may be more clearly defined. I Under no circumstances should roof downspouts be connected to the footing drain , systems. All roof downspouts must be separately tightlined to discharge. Cleanouts � should be installed at strategic locations to allow for periodic maintenance of the footing � i drain and downspout tightline systems. In no case should the roof drains be connected � _ _� to the retaining wall drainage system or the sub-slab drain system. i � � Utilitv Sunnort and Backfill � ' , Based on the soil conditions encountered, the soils expected to be exposed by utility � i excavations should provide adequate support for utilities. � . �I � � Earth Consultants, Inc.