11000 16TH AVE SE 2016-01-01 MF Import

� � � � Q � N � HX � ��i fC O i H 7tl oxo � H � � V1 H • [�7 O � ' H C7 OH �O � g c. What general types of soils are found on the site (for example, x N clay, sand, gravel , peat, muck)? If you know the classification � y of agricultural soils, specify them and note any prima farmland. ; HH I g �' H Based on soils classification mapping presented in the Soil � d � Survey of Snohomish County, Washington (USDA Soil Conservation � � � � Service,', the site's soils are within the Alderwood urban land ' z y �, complex series. HOfn Alderwood urban land complex is about 60 percent Alderwood gravelly sandy loam and about 25 percent urban land. The Alderwood soil is moderately deep over a hardpan and is . moderately well drained, bein9 formed in glacial till . The s�.�rface layer is very dark grayish brnwn gravelly, sandy loam about 7 inches thick. The upper part of the subsoil is dark yellowish brown and dark brown very gravelly, sandy loam about � 23 inches thick. The lower part is olive brown very 9ravelly � sandy loam about 5 inches thick. A weakly cemented hardpan is at a depth of about 35 inches. Depth to hardpan ranges from 20 to 40 inches. Permeability of Alderwood soil is moderately rapid above the hardpan and very slow through it. Runoff is slow and the hazard of water erosio� is slight. A seasonal '1_w� perched water table is at a depth of 18 to 36 inches from z_� January to March. Terra Associates has performed pr�eliminary subsurface soil investigations of the subject property (previously submitted) , I I�'�� with specific emphasis on areas planned for proposed buildings. , �s Included in the report is a description of fill areas on the site and a discussion of effects of on-site graaing more than 15 years ago. Evaluations were performed in the drainage swales � �'"'� � �" which occur on the site as remnants of a drainage channel which m� apparently flowed from north to south. At that time, although subsurface and surface waters were present, predominantly in � " poorly-drained areas within the central area of the site, no , occurrences of "boggy soils" were noted. The report suggests ' , �,� that during periods of heavy rainfall , water may collect in the � , depressions which are the drainageway remnants and that runoff '� migrates southward as subsurface seepa9e. � ( �1 � Visual reconnaissance and excavation of 15 backhoe test pits � ' '" were performed on the site. Test pits revealed a generalized �! soil sequence of 6 to 18 inches of duff/topsoil overlying two to 3 feet of loose to medium dense silty sands with tree roots, ...,,,,,�1 � , cobbles and gravel . Below this layer, very dense gravelly or silty sand glacial till was found. � � A fill area overlying the original soils was identified in the , south half of the property, just west of 16th Avenue S.E. , and , generally blocking the original drainage corridor. The fill �vas � found to consist primarily of loose to medium dense silty sands � I, 4 ' �