5700 23RD DR W 2016-01-01 MF Import

� � � � 1 Near the center of the stream craverse, the west slope of Narbeck Creek is characterized by dlted I cottonwood and alder trees and a concave shape suggestive of ongoing soil creep and shallow landslide topography. Colluvium was observed in cu[bank exposures at streazn level in this reach, ! � Similar slope condidons were also noted on the west slope of dx creek near the southern properry � boundary. IThe side slopes above the East Fork of Powder Mill Creek, located on the west side of the ' property, are not as deeply incised as Nazbeck Creek. No significant geologic exposures ware � observed along the East cork of Powder Mill Creek at the time of our field recounaissance. Vegetation in this drainage is extremely dense, limiting visibility. The stream bed consists of fine I sediment. A large storm water detention faciliry was ]ocaud jusc upstream of the properry on the Isouth side of 60th Street SW. 3.0 S TR�TIRFA('F Fxnr nuemrnwT i I The field reconnaissance and subsurface exploration of the property was conducted by Associated Earth Sciences, Inc. (AESn in May and August of 1995 during a previous phase of study at the site. Subsurface exploration conducted at that time consisted of excavating a series of exploration � piu to gain information about condidons at the site. The various types of sediments as well as the depths where the chacacterisdes of the sed'unents changed are indicated on the exploration logs presented in the Appendix. The depths indicated on the logs where conditions changed may 1 represent gradational variations between sedicients types in the field. Our explorations were ! � approximately locaced in the field by measuring from lrnown site features shown on a topographic ( survey of the site. 1 The conclusions and recommen� s presented in this report are based, in part, on the 21 exploration pits completed for ttri� ;� and on our slope reconnaissance. The�mber, locadon, � and depth of the explorations were .�mpleted within site and budgetary constraints. Because of the nature of exploratory work below ground, extrapolation of subsurface conditions between field explorations is �cessary, It should be noted thac differing subsurface conditions may sometimes ! be present due ro the random nature of deposition and the alteration of topography by past grading and/or filling. The nature and exunt of any variations betwan the field explorations may not � become fully evident undl construction. If variations are observed at that time, it may be � necessary to re-evaluate specific recommendations in tl�is report and make appropriau changes. I3.1 Exploration Pi c The exploradon pits were excavated with a backhce under subcontract W AESI. The pits I IQermitted d'uect, visua] observation of subsurface conditions. Maurials encounured in the exploradon piu were studied and classified in t6e field by an enginaring geologist from our firm. All exploration pits were bacl�illed immediately after examination and logging. Selxted samples Iwere then transported w our laboratory for further visual classification and testing, as necessary, F . 3 1