an upstream-facing BGM liner to minimize seepage through the structure. A deep cutoff trench to anchor the liner at the base in front of the dam over frozen ground was used to minimize the potential seepage through the dam foundation. To ensure permafrost was retained in the foundation, the foundation preparation, liner placement and covering were carried out from January through March and late October through December, when ambient temperatures were often near -40°F (-40°C). Installation of the liner was carried out through all seasons. Every extension of the rockfill dam from 2006 until today is watertight with a BGM of 0.2-inch (5.1-mm) thickness (Figure 7). BGM has advantages not only in cold weather conditions but also in hot weather conditions. It is effective in temperatures ranging from -49°F to 194°F (-45°C to 90°C). In Ireland, RUSAL Alumina is a large bauxite processing plant based in the southwestern part of the country. The clarifier pond had been badly leaking for quite a while due to inadequate performance of the existing HDPE geomembrane, which must store high-temperature liquid at 194°F (90°C). BGM uses a special bitumen compound with a temperature of penetration, which measures the penetration of a needle (test NFT 666004 or BS 200: Part 49), of 266°F (130°C). To meet the plant's waste license FIGURE 7 Cold weather installation at the Kinross Kupol Gold Mine in Russia Welding and testing equipment for the serious geosynthetics installer Pro-Wedge VM-20 Wedge Welder Over 6,000 units sold! Pro-Tester High-Pull Tensiometer for testing high-strength materials with new Auto-Engage feature (888) 324-WELD (9353) or 530 621-3200 Visit demtech.com or call for more product information. www.GeosyntheticsMagazine.com 17http://www.demtech.com http://www.GeosyntheticsMagazine.com