1815 13TH ST SEATTLE CHILDRENS NORTH CLINIC 2019-07-08

CENTRAL UTILITY PLANT PARKING LOT Everett,Washington PREVIOUS STUDIES We reviewed the logs of borings completed as part of GeoEngineers' previous studies in the vicinity of the project site. The approximate locations of those explorations are shown on the Site Plan, Figure 2. The reviewed geotechnical information includes the logs of six borings completed by GeoEngineers, Inc. in 2008. The logs of these borings are presented in Appendix C. SITE CONDITIONS Surface Conditions The proposed CUP parking lot will be constructed at the existing gravel parking lot located immediately east of the CUP building and across from the new parking garage. The ground surface in the vicinity of the planned CUP parking lot is relatively level. The existing CUP parking lot is bordered by residential houses to the north, the new CUP to the west, 13th Street to the south, and residential houses and Lombard Avenue to the east. Several underground utilities are present within and in the vicinity of the proposed new parking area. Subsurface Conditions Soil Conditions The soil conditions encountered in the test pits indicate that the parking lot site is generally underlain by fill, a former topsoil layer, and glacially consolidated soils. The materials encountered in the explorations are described below. At each of the test pit locations with the exception of test pits TP-8 and TP-9,crushed surfacing base course was encountered at the surface with a thickness of approximately 4 to 6 inches. FILL Fill was observed in each of the test pits, except for TP-4, TP-5, and TP-9, to depths ranging from 1 to approximately 4.5 feet below the existing ground surface. The fill generally consists of very loose to medium dense silty sand with varying gravel and occasional organic matter. FORMER TOPSOIL LAYER A thin layer of soft to medium stiff, organic silt was observed underlying the fill in test pit TP-1 and extended to a depth of approximately 7 feet below the existing ground surface. GLACIALLY CONSOLIDATED SOILS Glacially consolidated soils were encountered in the test pits below the fill and topsoil layer. The glacially consolidated soils consist of medium dense to very dense silty sand with varying gravel content and stiff to hard sandy silt and clay. Glacially consolidated soils were encountered in the test pits at depths ranging from near the ground surface to 7 feet below the ground surface. The glacially consolidated soils extend to the depth explored in each of the explorations. Cobbles and boulders are commonly encountered within glacial deposits. Page 2 October 17,2012 GeoEngineers,Inc. File No.10738-010-00