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r Golder Assoeiafes Ina 200 Union Boulevard. Suite 500 Lakewood. CO USA 80228 Telephone(3031980~0540 Fax(303J985-2080 May 26, 1995 Cripple Creek & V ictor Gold Mining Company 2755 State Highway 67 Victor, CO 80860 Attention: Mr. John Hardaway RE: POLY-FLEX VLDPE GEOMEMBRANE Dear John: GrOld('x ASSOC111~CS Reference No.: 943-2847 aFCEIVED MAY 3 0 1995 Dmslpn of ~.:I~netals ~ Geology Golder Associates Inc. (Golder) has reviewed the Quality Control (QC} certifications for the 80 mil smooth Very Low Density Polyethylene (VLDPE) manufactured for the Cresson Project by Poly-Flex Inc. (Poly- Flex). The material originally specified for the geosynthetic portion of the Cresson Project was VLDPE geomembrane manufactured by Gundle Lining Systems [nc. (Gundle). Gundle had an internal specification regarding the Compound Density of the VLDPE to be equal to or less than 0.925 grams per cubic centimeter (g/cc). As Gundle was the supplier of VLDPE for the project, Gundle's Quality Control speciftcation was incorporated into Golder' specifications. While Gundle was the manufacturer of the VLDPE geomembrane, Union Carbide waz the sole supplier of VLDPE Resin sold to the geomembrane market. In December of 1994, Union Carbide announced that they would no longer supply the VLDPE Resin to the geomembrane market. The Cripple Creek & Victor Gold Mining Company (CC&V) waz able to obtain approximately 1,000,000 square feet of 80 mil VLDPE from Gundle for the completion of Phase 1. However, another approximately 100,000 square feet of 80 mil VLDPE is required for the Phase I Completion and approximately 400,000 square feet of 80 mil VLDPE is required for the completion of the Phase II Underdrain system. Since Union Carbide is no longer manufacturing [he VLDPE Resin, it became increasingly difficult to locate any manufacturers oC VLDPE geomembrane. Poly-Flex was contacted in early March and stated they would be able [o provide the VLDPE required for the project (at a cost almost double to that paid in 1994). Specifications were provided to Poly-Flex, and in early May of 1995, began the manufacturing of the 80 mil smooth VLDPE. On Golder receiving and reviewing the VLDPE QC certifications, Golder discovered that the Compound Density for this material exceeded the 0.925 g/cc criteria identified in the project specifications. Poly-Flex pointed out that their own internal Compound Density criterion was less than 0.930 glcc for VLDPE. The compound density refers to the density of the final geoembrane product, and partially reflects the engineering properties exhibited by the geomembrane. It is an industry standard that VLDPE have a Compound Density less than 0.930 g/cc; Linear Low Density Polyethylene (LLDPE) have a Compound Density less than 0.94 gfcc; and High Density Polyethylene (HDPE) have a Compound Density in excess of 0.94 g/cc. The VLDPE manufactured by Poly-Flex does meet the Industry standards for VLDPE. In addition, the engineering properties reported in the Poly-Flex QC certifications, such as she tensile break, ultimate elongation and puncture resistance all meet the minimum criteria, as outlined in the project specifications. Therefore, based on a review of the engineering properties of [he VLDPE manufactured by Poly-Flex, Golder recommends that this material is acceptable and will function as per the intent of [he design. OFFICES INAUSfRALIA. CANADA. GERMANY, HUNGARY, ITALY, SWEDEN, UNITED KINGDOM. UNITED SPATES