501 RIVERSIDE RD REGIONAL DISPOSAL COMPANY EVT TRANSFER FACILITY PHASE 1 SITE IMP Geotech Report 2025-07-28

RDC EVERETTTRANSFER FACILITY su Everett,Washington 1 APPENDIX B LABORATORY TESTING Soil samples obtained from the explorations were transported to our laboratory and examined to confirm or modify field classifications, as well as to evaluate-engineering and index properties of the soil samples. Representative samples were selected for laboratory -testing consisting of moisture content, grain size distribution determination, percent passing the US No. 200 sieve, California Bearing Ratio (CBR), and Atterberg limits. The tests were performed in general accordance with test methods of the American Society for Testing and Materials (ASTM) or other applicable procedures. Soil Classification Soil samples obtained from the explorations were visually classified in the field and/or in our laboratory using a system based on the Unified Soil Classification System (USCS) and ASTM classification methods. ASTM test method D 2488 was used to visually classify the soil samples, while ASTM D 2487 was used to classify the soils based on laboratory tests results. These classification procedures are incorporated in the boring logs shown in Figures A-2 through A-9. Moisture Content Testing Moisture content tests were completed in general accordance with ASTM D 2216 for representative samples obtained from the explorations. The results of these tests are presented on the boring logs shown in Figures A-2 through A-9 at the depths at which the samples were obtained. Percent Passing U.S. No.200 Sieve Selected samples were "washed" through the U.S. No. 200 mesh sieve to determine the relative percentages of coarse-and fine-grained particles in the soil. The percent passing value represents the percentage by weight of the sample finer than the U.S. No. 200 sieve. These tests were conducted to verify field descriptions and to determine the fines content for analysis purposes. The tests were conducted in general accordance with ASTM D 1140, and the results are shown on the boring logs at the respective sample depths. Sieve Analyses Sieve analyses were performed on two samples within the fill soils in general accordance with ASTM D 422 to determine the sample grain size distribution. The wet sieve analysis method was used to determine the percentage ofsoil greater than the U.S. No. 200 mesh sieve. The results of the sieve analyses were plotted, classified in general accordance with the USCS, and are presented in Figure B-1. Atterberg Limits Atterberg limits testing was performed on selected fine-grained soil samples. The tests were used to classify the soil and to estimate index properties of the soil. The liquid limit and the plastic limit were performed in general accordance with ASTM D 4318. The results of the Atterberg limits are I GEOENGINEERS� June 18,2013 I Page B-1 File No.4322-002-00