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Project No. 364 571 Page 2 FIELD INVESTIGATIONS Our field investigation included drilling 2 exploratory borings on June 20, 1995 to depths ranging from 211/z to 31¥5 feet. The approximate locations of the borings are shown on Figure 2_ The borings were observed and logged by a geologist from our firm. Final logs of the borings are attached as Append/x A. The descriptions on the logs are based on field notes and sample inspection. The field investigation is discussed in Appendix A. SITE CONDITIONS The site is located approximately 100 feet southeast of the intersection of Ehlen Road and Dolores Way in an undeveloped property five miles west of Aurora. The site is surrounded on the west side by a commercial retail service station and on the south and east sides by undeveloped agricultural property. The site comprises part of the central portion of the broad lowlands of the Willamette Valley. The ground surface is level to gently sloping and covered by sparse grasses. A portion of the site is occupied by 3- to 5-feet high soil piles. As encountered in our test pits, the site is covered by about 2 to 4 feet of silty residual soil m/xed with angular basalt gravel road base imported for construction of the existing farm road immediately west of the site. Beneath the surface soils the site is underlain to a depth of tens to hundreds of feet of brown, firm to stiff alluvial silt. Portions of the silt contain varying amounts of woody organic debris deposited during the ancient flooding of the Willamette Valley. This organic debris was encountered at depths between 12½ to 15 feet below the existing ground surface (bgs) in both borings. The silty surface soil consisted of a 2- to 4-foot upper layer of damp, dark yellowish brown, firm to stiff silts containing up to 10% angular to rounded basalt gravels over a 31¥a-feet or thicker layer of dark greenish gray, firm to hard, silt to sandy silt subsoi/. As encountered in our borings, this silty soil contains wood debris ranging in size from partially decomposed fibrous matter to large logs up to I foot in diameter. This peaty organic matter composed up to a maximum of 40% of the soil sampled an approximately 5- to 15-feet thick interval from a minimum depth of approximately 12V2 feet bgs to a maximum of 27 feet bgs in Boring 1. No groundwater was encountered in either of our borings during our investigation on June 20, 1995. Permanent groundwater is believed to be located at a depth of tens of feet below the ground surface.