|EPA Publishes Final Steam Electric Effluent Limitation Guidelines|
EPA Publishes Final Steam Electric Effluent Limitation Guidelines
On September 30, EPA finalized the Steam Electric Effluent Limitation Guidelines. An estimated 1,080 coal, gas and nuclear power plants and any other new plants that come online will be required to use a mix of controls to minimize discharges of zinc, selenium, arsenic, mercury and other toxic pollutants. The rule does not apply to plants that are oil-fired or smaller than 50 megawatts.
Starting January 1, 2018, existing power plants will be required to use a suite of technologies that involve dry handling of fly ash and bottom ash and chemical precipitation and biological treatment of wastewater discharged from air pollution control equipment, including scrubbers for sulfur oxides and technologies that control mercury, oxides of nitrogen and particulates. Power plants that choose the more stringent process of evaporation to handle scrubber wastewater have until 2023 to comply with the effluent limits. At new power plants, EPA will require dry handling of fly ash and bottom ash similar to that for existing plants, with more stringent limits for flue gas scrubbers containing arsenic, selenium, mercury and total dissolved solids. The new plants also will be subject to new limits on arsenic and mercury for coal combustion leachate.
Specifically, the final rule among its various options will require:
• new effluent limits for arsenic, mercury, selenium, and nitrogen for wastewater discharged from wet scrubber systems;
• zero discharge of pollutants in ash transport water that must be incorporated into the plants’ discharge permits;
• zero discharge pollutant limits for flue gas mercury control wastewater; and
• stringent limits on arsenic, mercury, selenium and total dissolved solids in coal gasification wastewater, based on evaporation technology.
Not affected by the rule is legacy wastewater generated prior to January 1, 2018. The rule defines legacy wastewater as that which is involved in the transport of fly ash and bottom ash. It also includes wastewater generated by scrubbers, mercury controls and coal gasification processes.
Effluent limits for power plant discharges of toxic pollutants are based on the best available technology that is economically achievable as well as best practicable technology that is commercially available. Once effective, the effluent limits are incorporated into National Pollutant Discharge Elimination System permits issued to power plants. Upon implementation of the rule, EPA estimates annual reductions in 1.4 billion pounds of toxic pollutants and withdrawals of about 57 billion gallons of water.
For more information, go to http://www2.epa.gov/eg/steam-electric-power-generating-effluent-guidelines-2015-final-rule-documents.