3431 NASSAU ST 2018-01-02 MF Import

04/14/04 07:15 FAX 4253476588 CBBA EVERM Q 010/032 1 Genlognr. invea(i nninn and l ironvchnicnl (•:n¢inecrine Rerwrl 00-02-20 NF. Corner 350i St. and Nassau St. 1-wercu, Washington Seismic - intensity and dio•ation of ground motion SuilMoisture- onlymauratedsoilwillliyuef, Soil Grain Size - only fine-grained sands and coarse sills are affcc•red The dense sandy silt to silt soils of the Transitional lied (Qtb) or Whidby Formation (Qw) are generally to dense to liquify during a seismic event. While seismic energies are readily transmitted through the sandy silts, the density of the soil make liquefaction potentials slight. This report presents what are, to the best of our knowledge, normal geotechnical engineering recommendations and practices for private residential development on sites with slight liquefaction potential in this area. 3.5 Ground Water A "ground water" table was not encountered within the depths of the test pit excavations at the time of our site investigation. Transitional 3cds (Uth) is considered to be an aquiclude -- a soil that does not readily allow either vertical or horizontal transmission of ground water through it. Limited amour', ; of ground water seepage were encountered along the contact between the fill and the upper portions of the sandy silts (Qtb) horizon during our site investigation. This zone contained occasional discontinuous lenses of sand that were saturated with water. Seepage was observed within these lenses during our site investigation and appeared to be perched around elevation el. 173.5 to el. 174.0. Seepage abated over time once the hole had been excavated. We believe that the encountered seepage is seasonal. Seepage was also observed in test pit 2 at an elevation of approximately el. 183. We believe that this was also a discontinuous saturated area that would abate over time if left exposed. 6 GES, Inc.