2016-01-14_REPORT - M1980244 (15)

Home Browse Search

Cripple Creek & Victor Gold Mining Company Squaw Gulch VLF Phase 1 (9,550-foot Elevation Bench to Geomembrane Panel P1635) Final Report Quality Assurance Monitoring & Test Results January 2016 Project No.: 74201125N0 Page 11 2.7 Project Composite Liner System The Project is a single geomembrane composite liner system: • The composite liner system in the Project consists of a minimum of 12 inches of compacted SLF overlain by a layer of 80-mil DSMS LLDPE geomembrane. • The HVSCS is installed over the geomembrane liner. The HVSCS consists of HVSCS piping and DCF placed at a minimum of 2 feet thick. The HVSCS is discussed further in Section 2.8. The installation of the geomembrane layers for the Project began June 2015 and was completed in November 2015. ECA installed approximately 3,196,925 square feet (neat line) of 80-mil DSMS LLDPE geomembrane liner according to the project technical specifications. Geomembrane installation for the Project is discussed further in Section 3.3. Ames anchored geomembrane in an anchor trench measuring 3-feet-deep by 2-feet-wide. Ames backfilled the anchor trenches with suitable anchor trench backfill material (per Note 1 and Details on IFC Drawing A220). In places where future geomembrane liner covers the anchor trench, SLF material was used to backfill the top 12 inches of the anchor trench to form a continuous clay liner. Ames placed anchor trench backfill in maximum 12-inch-thick compacted lifts. Anchor trench backfill was compacted with a hand operated, minimum of 500 pound, vibratory compactor and “Jumping Jack” compactors, or a smooth drum vibratory roller, if conditions allowed, to the project technical specifications. 2.8 High Volume Solution Collection System The HVSCS is comprised of HVSCS piping and drain cover fill. The HVSCS piping layout and details are presented on IFC Drawings A400 and A410. Ames installed approximately 31,664 linear feet of 4-inch-diameter perforated CPe tertiary HVSCS pipe, 4,016 linear feet of 8-inch-diameter CPeP solution collection pipe, 4,162 linear feet of 12-inch-diameter CPeP solution collection pipe, 1,087 linear feet of 15-inch-diameter perforated CPeP solution collection pipe, 1,641 linear feet of 18-inch- diameter CPeP solution collection pipe and 1,061 linear feet of 24-inch-diameter CPeP solution collection pipe. Ames began installing the perforated CPe HVSCS pipe in June 2015 and completed in November 2015. Pipe locations are shown on Record Drawing No. 4 in Appendix A. Ames placed DCF under the pipe haunches and kept pipes in place during DCF placement.