1901 MERRILL CREEK PKY 2018-01-01 MF Import

� Two small, shallaw slope failures were obsecved within the extreme astem portion of the property along the east bank of Mertill Ring Crak, and a third shallow slope failure was ` observed on the wat bank of Narbeck Cmk northwat of the property. All three slope failures � occur in gray laminated silts with occasional sand (transition beds of the Whidbey fortnation). r_ The recent failura on the east side of Menill Ring Creek measure less than 30 fat by 20 feet • and are about 3 fat dap. Thae failures occur on the over-stapened banks and may have been triggered by the extraordinary winter stortns of 1996-1997. The older failurc on Narbeck Creek, r which is slightly vegetated, occurs on a very steep silt bank and measures about 25 feet by 1 25 feet and is a few fcet deep. Slight slope creep was observed on the east bank of Narbeck Creek at the north end of the propecty. The soil surface, which is derived from till and outwash that overlies the transition beds, is loose. A few tnes near the middle of tFie slope exhibit minor uunk bowing. Eztensive burrowing by animals near the crest of the slope has turther loosencd this material. Fallen trees, most likely toppled by wind, were observrl in this area and elsewhere on the property. ` We did not observe any springs or ground water saps during our August rxonnaissance. I SUBSURFACE CONDITIONS r - ' Sotl Conditions Subsurface soil and ground water conditions were ezplored by excavating ten test pits('CP-1 ; through TP-10) at the approximate locations shown on the Site Plan, Figuro 2. Details of the � field exploration program, labontory analysa, and the exploration logs arc presented in � Appendiz A. , In general, the subsurface conditions encountered in the tat pits and during our site reconnaissance concur with conditions dacribed in previous reports and in geologic maps of the i area. A thin layer of topsoil and forest duff overlying glacial till was encountered in the upland � portions of the site, and transitional beds end hard silt of the Whidbey fotmation were observed ( near the creek. More specific descriptions an provided in the following paragpph. We rypically encouniered 6 to 8 inches of topsoil beneath a loose Iayer of forest duff. The topsoil consists of silry sand with occasional gravel and organic matter. A 2.5- to 4foot � thickness of weathered till was rypially encountered below the topsoil. The till becoma unwwthered and dense to very dense below the wathered zone. The till consists of silty sand ' with occasional gravel and cobbles. Occasional boulders should also be ezpected within the � glacial deposits. The till cap was not encountercd in two of the test pits ('fP-7 and TP-8), A , cleaner deposit of what appears to be advance outwash was encountered below the topsoil in these ' explorations. � Ground Water Ground water see�a,�e wu not encountered in a�y of the test pit explotatiom and we did i not obsen�e any springs�r•: :�ps during our August reconnaissance. Minor qnantltia of perched i_ ground water should be ezpected in uas underlain by glui�t till or hud tilt aiter periods of f O e o E n � i n e e r � 3 F{IeNo. t/60-006�7l-1130/tl@97 �