Water Effluent Limits for Steam Electric Power Generating
Most Recent Action
In September 2009, EPA decided to proceed with rulemaking in the Steam Electric Power Generating Industry. Effluent guidelines have not been updated since 1982. Proposed rulemaking is expected in July 2012 and Final action by January 2014.
Background
Under the Clean Water Act, EPA establishes national technology-based regulations, or “effluent guidelines,” to reduce pollutant discharge from industries into U.S. waters. The guidelines are industry specific.
The steam electric effluent guidelines apply to steam electric power plants using nuclear or fossil fuels, such as, oil, coal or natural gas. There are approximately 1,200 nuclear and fossil-fuel steam electric power plants in the United States.
Based on findings from an EPA multi-year study of the Steam Electric Power Generating industry, the EPA plans to review current effluent guidelines. During the study, EPA reviewed wastewater discharges from power plants and concluded that the 1982 effluent guidelines were outdated and insufficient. EPA’s decision to review the effluent guidelines was announced on September 15, 2009. During the course of the study, EPA identified certain technologies that could significantly reduce pollutant discharge.
Twice, the EPA requested public comment on a draft questionnaire to be distributed to specific plants within the scope of a potential proposed rule. The second round of public comment ended March 9, 2010. The purpose of the questionnaire was to collect general information about plants and the technologies used in plant processes and the electric generating units.
A proposed rule regarding the new effluent guidelines is expected in July of 2012, and final action is expected in January of 2014.
This rule is part of a group of rules known as the EPA's Regulatory Train Wreck.
Authority
Sections 301; 304(b), (c), (e), and (g); 306(b) and (c); 307(b) and (c); and 501, Clean Water Act (Federal Water Pollution Control Act Amendments of 1972, as amended by Clean Water Act of 1977).
Standard
The current effluent guidelines, establish in 1982, require the following:
Once Through Cooling Water
Best Available Technology Economically Available (BAT) and NSPS are based upon a concentration of 0.2 mg/l total residual chlorine (TRC), applied at the final discharge point to the receiving body of water. Each individual generating unit is not allowed to discharge chlorine for more than two hours per day, unless the discharger demonstrates to the Permitting authority that a longer duration discharge is required for macro invertebrate control. Simultaneous chlorination of more than one generating unit is allowed. The above limitation does not apply to plants with a total rated generating capacity of less than 25 megawatts. BAT and NSPS are equal to BPT for those plants. With the exception of a prohibition on the discharge of PCBs, there are no national pretreatment standards applicable to once-through cooling water.
Cooling Tower Blowdown
The limitations are 0.2 mg/l average concentration and 0.5 mg/l daily maximum concentration, with multi-unit chlorination prohibited.
Fly Ash Transport Water
There are no BAT limits or PSES with the exception of a prohibition of PCB discharges. The existing BAT limits for conventional pollutants are withdrawn because they will be covered by Best Conventional Pollutant Control Technology (BCT) limitations.
Bottom Ash Transport Water
There are no BAT limits or pretreatment standards, with the exception of a prohibition on
PCB discharges.
Related Documents
40 CFR 423 – Steam Electric Power Generating Point Source Category
EPA’s Study of the Steam Electric Power Generating Industry, October 26, 2009