4704 HARBOR LN 2018-01-02 MF Import

Proposal for Geotechnical Services Anderson Landslide Repair Everett, Washingtcn NGA Proposal No. P91280 August 21, 2009 Page 2 soil. We also observed large trees lying on the slope below the residence. It is our understanding that the trees were cut down approximately three weeks prior to (lie slide. INITIAL. OPINION & RECOMMENDATION It is our initial opinion that the landslide is still fairly active and conditions could worsen if the slide is not promptly repaired. It is very important to temporarily secure this site as soon as possible until a nermancnt solution can be intplenientedUWe recommend that the water in the pool and Jacuzzi be .emptied immediately, as any leakage of those elements could cause further damage to the slopN c also recommend that the trees that are lying on the slope be cut into smaller pieces and be removed from the sl�c. Care should be taken white removing the tress as to not cause further disturbance to the slop�*c also recommend that all of the downspouts and footing drains for the residence be located and tightlined into a temporary syst_ cm to prevent water from [lowing onto or over the slope(? - he temporary drainage system should be routed to the bottom of the slo ne. Also, after our field work is completed by mid week next week, at a minimut , the upper portion of the slope should be covered with plastic and the plastic secured with sandbags to protect the expo<cd soil front the elements and further erosion. For the permanent slope repairs, we propose to drill tour geotechnical borings using a portable (hill rig and collect soil samples. Along with the mapping of the slope and our soil explorations, we will analyze the over-all slope stability of the area. It is our initial opinion that a ,Adier-pile type wall system along with erosion control, and drainage systems will be needed to permanently stabilize the slope. We will work with a qualified structural engineer to complete the design. The stabilization of the slope below the wall is also extremely important. We will provide specific recommendations for several site drainage, erosion control, and vegetation management. A contractor specializing in re -vegetation of steep slopes as well as a biologist will need to be consulted, We will work with these consultants in preparing a re - vegetation plan that will provide a stable slope. SCOPE. We propose to provide temporary recommendations for stabilizing the slide, and also work with you and other consultants to provide a permanent solution for the slide. Based on our understanding of site conditions, the services to be provided by NGA are to: Review available soil and geologic maps of the area. NELSON GEOTECHNICAL ASSOCIATES, INC.