Deciphering the Choices in Treatment Required to Meet EPA Effluent Limitation Guidelines at Coal-Fired Generating Stations

摘要

In 2009, US Environmental Protection Agency (EPA) under authority of the Clean Water Act elected to proceed with rulemaking in the form of revised Effluent Limitation Guidelines (ELG's) for the steam electric power generating industry. Draft ELGs are scheduled for public release in November 20, 2012 with final release scheduled for 2014. The standards will redefine the wastewater management requirements for many coal-fired power plants. The ELG's are based on best available technologies with consideration for the potential economic impacts. As a result, utilities will need to navigate through a host of different technological approaches and considerations to achieve the expected limits for constituents such as selenium, mercury, boron and total dissolved solids (TDS). These standards will be implemented through the National Pollutant Discharge Elimination System (NPDES) permit limits. For many utilities, tighter NPDES limits will force the implementation of treatment of flue-gas desulfurization (FGD) and ash handling streams. Utilities, consulting engineers and treatment technology providers will have to work together to evaluate, select, procure, construct and commission new treatment facilities. At the same time, careful consideration must be given to the challenges faced in implementing the appropriate solutions. Dynamic water qualities, variable fuel sources, technology capabilities, concurrent implementation of other air and water controls, vendor and consultant experience in this arena must be part of the equation. This paper examines the decisions faced by facilities as they navigate through these choices in order to successfully and economically meet the new requirements in a changing environment.