7710 EVERGREEN WAY NEW CINGULAR WIRELESS ANTENNA 2016-09-26

� �J Adapt Engineering during soil fill placement. In this way, the adequacy of soil compaction efforts may be evaluated as earthwork progresses. Fines Content: Soils used for structural fill should not contain individual particles greater than about 6 inches in diameter and should be free of organics, debris, and other deleterious materials. Given these prerequisites, the suitability of soils used far structural fill depends primarily on the grain-size distribution and moisture content of the soils when they are placed. When the "fines" content (that soil fraction passing the U.S. No. 200 Sieve) increases, soils become more sensitive to small changes in moisture content. Soils containing more than about 5 percent fines (by weight) cannot be consistently compacted to a firm, unyielding condition when the moisture content is more than about 2 percentage points above optimum. The near-surface and deeper sands and gravels with cobbles and varying amounts silts and clay should be considered to be moderately moisture sensitive. The use of "clean" soil is necessary for fill placement during wet-weather site work, or if the in-situ moisture content of the sandy site soils is too high to allow adequate compaction. Clean soils are defined as granular soils that have a fines content of less than 5 percent (by weight) based on the soil fraction passing the U.S. 3/4-inch Sieve. CLOSURE The conclusions and recommendations presented in this report are based, in part, on the explorations that we performed for this study. If variations in subsurface conditions are discovered during earthwork, we may need to modify this report. The future performance and integrity of the tower foundations will depend largely on proper initial site preparation, drainage, and construction procedures. Monitoring by experienced geotechnical personnel should be considered an integral part of the construction process. We are available to provide geotechnical inspection and testing services during the earthwork and foundation construction phases of the project. If variations in the subgrade conditions are observed at that time, we would be able to provide additional geotechnical engineering recommendations, thus minimizing delays as the project develops. We are also available to review preliminary plans and specifications before construction begins. AT&T Mobility c/o Ryka Consulting May 5, 2014 Adapt Project No. WA14-18929-GEO Page 12