Polymer Treatment to Reduce Cost of Sludge Disposal

This presentation will show how metal-contaminated sludge in settling ponds can be efficiently separated producing clean water and solid waste for non-hazardous disposal. In 2007, Clear Water Compliance Services, Inc. provided a portable flocculation and filter-press system at the Leviathan Creek bioreactor and successfully treated 350,000 gallons of sludge. Snowmelt, rain, and groundwater interact with the waste rock from a century of mining operations, creating sulfuric acid, which in turn leaches additional contaminates from the native materials. The resulting acid rock drainage (ARD) flows into the stream system at numerous points, eventually joining the East Fork of the Carson River. The bioreactor protects the stream by raising the pH and reducing the dissolved metal concentrations in the water. However, the need to remove sludge from the settling ponds in order to continuously treat the contaminated water creates a significant hazardous waste disposal problem. By flocculating the sludge with a biopolymer and pumping the concentrated sludge to a filter press, a solid product with reduced leachability is produced allowing transport and disposal without hazardous waste characteristics. We were able to reclassify the waste stream to non-hazardous waste and reduce disposal costs by over 50%.