The new EPA effluent limitations guidelines (ELGs) will reduce or eliminate toxic metals and other pollutants from entering surface waters from steam electric power plants. The rules specifically address FGD wastewater from coal-fired power plants and identify chemical precipitation followed by biological treatment as the best available technology for treating and discharging the waste from existing plants and evaporation/pozzolanic solidification for new facilities.

In addition, the ELGs identify the evaporation/solidification approach as a best available technology for eliminating FGD waste streams from existing power plants under a voluntary incentive programme.

GE reports that its new evaporation/solidification technology reduces chemical addition, sludge handling and energy costs. It reduces the long-term environmental risks associated with the discharge of FGD purge water and other liquid streams from power plants. The system produces high-quality water for recycle and reuse. Specifically designed for FGD wastewater, it is cost-effective and offers significant reductions in both capital and operating expenses compared to traditional Zero Liquid Discharge (ZLD) systems, the company says.

GE's evaporation/solidification technology provides power plants with maximum flexibility because it can treat FGD wastewater from any type of coal and removes the risk of meeting stringent discharge requirements by eliminating liquid discharge to waterways. This approach also significantly reduces the risks to operators associated with the management of solid landfill waste.