832 RUCKER AVE 2016-01-01 MF Import

I � Proposed Modification to the Residence of Joel 8 Kathy Larsen Everett, Washington 4.2 Subsurtace Soil and Groundwater February 12, 2004 ORA Project Number: 04-065-Report 1 The subsurface soil and groundwater conditions at this site are described in the following paragraphs and are presented graphically on the boring logs in the Appendix of this report. The stratification lines indicated on the boring logs represent the approximate boundaries between soil types. Actual boundaries may be gradual and the transitions may not be easily discernible during site excavation. The surface of the site has been reworked somewhat due to the recent demolition and grading activity. Therefore, topsoil was present to d depth of about one-foot in Boring 1 and not present in Boring 2. In general, the soils extending to a depth of about 10 feet are brown to gray, very loose to loose, Silty SAND (SM) or very soft to soft SILT (ML). The Standard Penetration Resistance ("N-Value") of these soils ranges from 2 to 6 blows per foot (averaging 4 blows per foot) at natural moisture contents ranging from 16.5 to 55.3 percent. Underlying these weak, compressible soils; gray-brown to gray, stiff to hard, SILT (ML) to Clayey SILT (MH) was, in general, encountered to the termi�ation depth of the borings — 25.5 feet. A three-foot thick layer of brown, medium- derse Silty SAND (SM) was encountered at a depth of 15 feet in Boring 2. The "N- �alue" of these soils ranges from 11 to 85 blows per foot at natural moisture contents ranging from 10.6 to 32.4 percent. Groundwater was encountered in both borings at completion. Boring 1 was left open for 90 minutes before backfilling for the purpose of obtaining a more accurate groundwater elevation. Groundwater readings in granular soils, such as those encountered at this site, are generally accurate even after short periods of observation. Whereas, the groundwater level in fine-grained (silt and clay) soils, may require several days of observation before it becomes stable and accurate. 5. DISCUSSION IThe recommendations presented in this report are based on our understanding of the project as presented in the Project Description Section and on the assumption that the � subsurface conditions encountered in the borings adequately represent conditions near and between the exploratory borings. Because project conditions regarding type and Otto Rosenau 8 Associat�s, Inc. Page 4 of 13