2019-10-25_REVISION - M1980244 (11)

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NEWMONT GOLDCORP of 8, 7, and 9, respectively. Please address why these three samples were approved with an exceedance of the Technical Specifications. As stated in Section 2.1 of the Earthworks Technical Specification (Section 02200.0): "Acceptance of non❑conforming materials: In cases where non❑ conformance to these material specifications occur the Design Engineer in tandem with the Manager can approve the material for use, if in their opinion, the specification deviation does not diminish functionality of a given design element and/or compromise the design intent. If non[]conforming materials are accepted by the Design Engineer and Manager for use during construction, the DRMS will be contacted to alert them to the acceptance and rationale behind acceptance of non❑conforming materials." As required by the Technical Specifications and ASTM D4318 Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils, material passing the #40 (425-pm) sieve was retained and used for testing of the Phase 2A Drain Cover Fill (DCF). The Technical Specifications specifically states that the measured plasticity index should be zero, but the design intent of the Specification is that the DCF is a non-plastic material (this is something that will be rectified for further designs at CCV). Non-plastic is commonly considered material that has a plasticity index less than 5. The measured Plastic Index results of each sample was: • DCF-7-R = 8, • DCF-8-R = 7, and • DCF-9-R= 9. The percent passing the #40 sieve results were 13.2%, 15.2%, and 10.5% respectively. ASTM D2487 Standard Practice for Classification of Soils for Engineering Purposes(Unified Soil Classification System)was used in conjunction with the particle-size distribution results, and each sample was classified as follows: • DCF-7-R Poorly Graded Gravel with clay and sand (GP-GC), • DCF-8-R GP-GC, and • DCF-9-R Well Graded Gravel with clay and (GW-GC). The materials are predominantly gravel sized crushed rock,with coarse sand being the secondary constituent, and fine sand, silt, and clay the tertiary constituents. Whereas some of the finer fraction of these samples were outside the Specifications, the DCF material, as a whole, is considered non-plastic. Predominately course-grained material is considered non-plastic because the overall properties are defined by the dominant constituents of sand and gravel. In addition, the DCF provides two functions in the facility design: (1) a drainage layer for solution over the geomembrane liner; and (2) as a protective layer for the geomembrane liner. The DCF will provide protection for the liner system,and based on the location where these samples were taken (along the Phase 2 slopes), the