COMPLIANCE INFO_FINAL WMU FU-23 DESIGN RPT & CONCURRENCE LTRS

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Forward, Inc. - 2 - 6 November 2023 Forward Landfill The 2:1 side slope liner components of WMU FU-23 consist of the following, from top to bottom: • 12-inches thick protective operations layer • Geocomposite drainage net • 60-mil single sided textured (SST) HDPE geomembrane liner • Geosynthetic clay liner (GCL) • Subgrade The CQA Report provides the results of field and laboratory CQA testing conducted during installation of WMU FU-23’s containment system components. The report includes detailed description of earthwork and LCRS testing and installation, such as particle size analysis, hydraulic conductivity, relative compaction, and optimum water content determination. CQA testing for geosynthetics layers, including GCL, geomembrane, geocomposite, and geotextile, include receiving and deployment logs, conformance tests, manufacture’s certification, and interface shear testing. Design modifications, including changes to technical specifications and the submitted design report, were also documented as well as other CQA activities and results. CQA activities included a leak detection test of the base and side slope HDPE geomembrane liner. Leak detection testing was conducted before and after installation of the LCRS and operations layer. The methods used were the Water Puddle Method (ASTM D7002) for the exposed HDPE geomembrane and the Dipole Method (ASTM D7007) for the geomembrane covered with soil material. Repairs included one hole found during the Water Puddle test. The CQA Report includes a detailed description of the above CQA activities along with project information such as construction specification; as-built survey drawings; daily field reports and photographs; and LCRS piping survey map. The following variances and revisions from the approved design plans were reviewed and approved by the design firm, Lewis Engineering. These variances and revisions include: • The peel strength of the GCL did not meet the minimum specification of 10 lbs/inch. The design firm assessed that the interface shear strength for GCL/geotextile/geocomposite drainage net met the interface shear strength test requirements and therefore the lower values for GCL peel strength are acceptable. The design firm approved the design variation via stamp and signature. • The large-scale direct shear test results did not meet the specification for interfaces and normal loads. The design engineer reviewed and approved the results after reanalyzing the slope stability. • The granular drainage material was out of specification. The sieve analysis for the LCRS granular drainage material indicated 92% passing the 3/8‐inch sieve and less than 3% passing the No. 200 sieve. The specification required