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October 25, 2015 <br /> YMCA- Everett <br /> L&A Job No. 15-089 <br /> Page 18 <br /> Agriculture) Texture Triangle chart, a copy of which is shown on Plate A2 in the attached <br /> Appendix. The classifications of soil samples are presented in the table below. <br /> USDA TEXTURE TRIANGLE CLASSIFICATION OF SOIL SAMPLES <br /> Sample Test Percentage Percentage Percentage USDA Texture <br /> No. Pit No. Clay Silt Sand/Gravel Triangle Classification <br /> 1 TP-2 1.1 3.7 95.2 Sand <br /> 2 TP-2 1.1 5.7 93.2 Sand <br /> 3 TP-7 1.0 5.6 93.7 Sand <br /> 4 TP-10 0.0 3.8 96.2 Sand <br /> Infiltration Rates <br /> Volume III, Section 3.3.6, Article 3 - Soil Grain Size Analysis Method, of the Stonnwatcr <br /> Management Manual for Western Washington, 2012 Edition, published by Washington <br /> State Department of Ecology, is used to determine estimated design infiltration rates of the <br /> target soil deposits. This method uses D10 , D60, D90, and fines in calculating the saturated <br /> infiltration rate (conductivity), Ksat in cm/sec; where D,o , D60, D90 are the sizes in <br /> millimeters of soil particles of 10%, 60%, and 90%, respectively, passing by weight, and <br /> (fines is the fraction of the fines passing the No. 200 sieve by weight (i.e., the sum of clay and <br /> silt). The values of D10 , D60, D90, and fines are shown or obtained from test result on Plate <br /> A-1, and the determination of Ksat for the four soil samples are shown in the table below. <br /> LIU & ASSOCIATES, INC. <br />