3606 W MUKILTEO BLVD 2016-01-01 MF Import

Gcotechnicnl Enginccring Evaluation Mukiltco E3oidevard Dcvclopmcnt Everett, Washington March 31, 2003 NGA Pilc No. 3GG503 Pagc 5 and is impcded by less pennenble soils at depth. 7'hc amounts of perched ground water tcnd to vaq• depending upon thc amount of rcchargc. Wc would cxpect that perched ground water would be more prevnlent during the wetter timc� of thc year. Ilowever, based on our crplorations, we anticipate that the majority of the site soils will remain rclntively wet evcn during thc summer months. We anticipate that thc wet conditions may impact sitc grading operations and lhc ability to use on-site material as structurnl ru. Erosion Hazard The erosion ha�ard criteria used for detennination of affected arcas includes soil type, slope gradient, vegetation cover, and ground water conditions. The erosion sensitivity is related to vegetative cover nnd thc specific surfacc soil types, ��hich are related to the underlying geologic soil units. The Soil Survev of Snohomish Countv Area, 1Vashington, by the Soil Conservation Scrvicc �vas reviewed to dctcmiine thc erosion hazard of the on-site soils. The site surfacc soils werc classified using the SCS classificntion system as Aldenvood gravelly sandy loam (15 to 25 percent slopes). The suils wc encountered in our exploratimis are consistent �vith the Aldenvood gravclly sandy loam soils. Wc consider the crosion ha��rd of thc natiac soils ta bc modci:�tc if distunc�d. Scismic I'otential '['hc projcct sitc is locatccl witliin "!_onc 3 of thc Scismic 7.unc Map sho��n :+s Figurc IG-^_ of tlic 1997 Uniform 13uilding Code (UDC). This corresponds to a Scismic 7onc Puctor, Z, of 030. We recommend that thc subsurfncc soils bc considcred Soil Profilc Typc S�, as dcscribcd in thc UE3C. 1Ia�lyds nssociatcd witl� scismic activiry includc liqucfaction potential and amplification of ground molion. Liqucfaction is causcd by a risc in porc pressures in a loosc sand dcposit hcncath Uie groimd ��•atcr tablc. Thc mcJium dcnsc to dcnsc, glacially-consolidatcd soils thnt arc intcrpretcd to undcrlic thc sitc havc a lo�v potcntial for liqucfaction or amplification of ground motion. CONCLUti(ONS AND RECOMMF.NDATiONS Cencral Il is our opinion thnt thc site is ��»n��;t,i�, r�o�» a ecotechnical standpoint, with the planned dc��clopment. l3ascd on our subsurface esplorations, thc underlying native soils should providc adequate support for thc pinnned structures. 9'hc planncd structures could generally be supported on shallow NELSON GEOTECHNICAL ASSOCIATES, INC.