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3.11 DEFECTS AND REPAIRS <br />A. All seams and non -seam areas of the geosynthetic shall be observed by <br />CQA Monitor for defects, holes, blisters, undispersed raw materials, and <br />any sign of contamination by foreign matter. The surface of the <br />geosynthetic shall be clean at the time of observation. The geosynthetic <br />surface shall be brushed, blown, or washed by Contractor if the amount of <br />dust or mud inhibits inspection. Project Manager and Engineer -ofF- <br />Record shall determine if cleaning of the geosynthetic is needed to <br />facilitate observation at no additional cost to Rio Grande Silver. <br />B. Each suspect location in seam and non -seam areas shall be non - <br />destructively tested as determined appropriate by CQA Monitor, in the <br />presence of CQA Monitor. Each location that fails the non - destructive <br />testing shall be marked by Contractor, and repaired accordingly. <br />C. Repair Procedures <br />1. Defective seams shall be reconstructed as described in these <br />Specifications. <br />2. Small holes shall be repaired by abrading the sheet surface and <br />welding an extrusion bead. If the hole is larger than 1/4 inches in <br />diameter it shall be patched. <br />3. Tears shall be repaired by patching. Where the tear is on a slope <br />or an area of stress and has a sharp end, it must be rounded prior <br />to patching. <br />4. Blisters, large holes, undispersed raw materials, and <br />contamination by foreign matter shall be repaired by patches. <br />5. Surfaces of geosynthetics that are to be patched shall be abraded <br />and cleaned no more than fifteen (15) minutes prior to the repair. <br />No more than ten (10) percent of the thickness shall be removed. <br />D. Patches shall be round or oval in shape, and extend a minimum of 6 <br />inches beyond the edge of defects. All patches shall be of the same <br />compound and thickness as the geosynthetic specified. All patches shall <br />have their top edge beveled to an approximately 45 degree angle with an <br />angle grinder prior to placement of the patch. Patches shall be applied <br />using approved methods only. <br />E. The extrusion welding process shall restart by grinding the existing seam <br />and rewelding a new seam. Welding shall commence where the grinding <br />started and must overlap the previous seam by at least 2 inches. <br />Reseaming over an existing seam without regrinding shall not be <br />permitted. <br />Rio Grande Silver Tailings Evaporation Pond 02620 -23 Geosynthetic Liner <br />August 2011 02620 <br />