8920 EVERGREEN WAY THE RESERVE 2025-07-25

Zipper Geo Associates, LLC Reserve at Everett Project No. 1117.01 May 1,2013 • Description Value 2009 IBC Site Classification C SS Spectral Acceleration for a Short Period 1.226 g(Site Class B) Si Spectral Acceleration for a 1-Second Period 0.432 g(site Class B) Fa Site Coefficient for a Short Period 1.0(Site Class C) F„Site Coefficient for a 1-Second Period 1.368(Site Class C) SMS Maximum considered spectral response acceleration 1.226 g(Site Class C) for a Short Period SM1 Maximum considered spectral response acceleration 0.591 g(Site Class C) for a 1-Second Period SDS Five-percent damped design spectral response • 0.817 g(Site Class C) acceleration fora Short Period SD1 Five-percent damped design spectral response 0.394 g(Site Class C) • acceleration for a 1-Second Period • 1. In general accordance with the 2009 International Building Code, Table 1613.5.2. IBC Site Class is based on the average characteristics of the upper 100 feet of the subsurface profile. 2. The test pits completed for this study extended to a maximum depth of 16.5 feet below grade. ZGA therefore determined the Site Class assuming that very dense soils extend to 100 feet as suggested by published geologic maps for the project area. • Ground Surface Rupture: Based on our review of the USGS Quaternary age fault database for Washington State,there does not appear to be a mapped Quaternary fault within a 10 mile radius of the site. Based on the reviewed database, it is our opinion that the risk of ground surface rupture at the site is low. • Landsliding: Based on the gently sloping topography of the site and surrounding vicinity, it is our opinion that the risk of earthquake-induced landsliding is low. Soil Liquefaction: Liquefaction is a phenomenon wherein saturated cohesionless soils build up excess pore water pressures during earthquake loading. Liquefaction typically occurs in loose soils, but may occur in denser soils if the ground shaking is sufficiently strong. The potential hazardous impacts of • liquefaction include liquefaction-induced settlement and lateral spreading. The soils encountered in our explorations are very dense and not considered susceptible to liquefaction. It is our opinion the risk of liquefaction at the site is very low. Stormwater Infiltration Feasibility The Glacial Till soils observed in the test pits generally contain a significant fraction of fines and are in a relatively dense condition. For purposes associated with stormwater infiltration, Glacial Till is generally Page 6