600 RIVERSIDE RD Geotech Report 2022-10-25

APPENDIX B LABORATORY SOIL TESTING Soil samples obtained from our exploratory test pits and borings were taken to our laboratory for further examination and testing. Laboratory tests were performed on representative soil samples to characterize certain engineering and index properties of the soils at the project site. The laboratory testing program, which was performed in general accordance with the ASTM International (ASTM) standard test procedures noted below, was limited to visual inspection to confirm our field soil descriptions, and determination of natural moisture content, certain Atterberg limits, and grain size distribution. A brief description of the testing performed is presented below. Natural Moisture Content 1 The natural moisture contents of selected soil samples obtained from the exploratory test pits and borings were determined in general accordance with ASTM D 2216 test procedures. The results from the moisture content determinations are indicated adjacent to the corresponding samples on the summary logs presented in Appendix A. 1 1 I Atterberg Limit Analysis The Atterberg limits test was performed on selected soil samples obtained from the exploratory test pits and borings in general accordance with ASTM D 4318 test procedures. The purpose of the test was to determine the liquid limit, plastic limit, and plasticity index of fine-grained material. Atterberg limits results are summarized on Figure B-1. Grain Size Analysis Sieve and combined sieve and hydrometer analyses were conducted on selected soil samples obtained from the exploratory test pits and borings in general accordance with ASTM D422 test procedures. Samples selected for grain size analysis are designated with a "GS" in the column labeled "Test Data" on the summary test pit and boring logs. The test results are presented in the form of grain size distribution curves on Figures B-2 and B-3. Agricultural Soil Analyses Under subcontract to Landau Associates, SoilTest Farm Consultants of Moses Lake, Washington performed a series of agricultural soil analyses on 5 near surface soil samples that were collected by LAI personnel along the proposed trail alignment at the approximate locations illustrated on the Site and Exploration Plan (Figure 2 of this report). The results of this testing are presented in the SoilTest Farm Consultants reports that are attached to the end of this appendix. Each report includes SoilTest Farm Consultants' recommendations related to what soil amendments are needed to support growth of the plants proposed along the trail alignment (at -grade riparian plants native to western Washington). B-1 1