Combustion Portal


Power Plant

Power Plants

A power plant or station is an industrial facility for the generation of electric power. At the center of nearly all power stations is a generator, a rotating machine that converts mechanical energy into electrical energy by creating relative motion between a magnetic field and a conductor. The energy source harnessed to turn the generator varies widely. It depends chiefly on which fuels are easily available and on the types of technology that the power company has access to.

This section covers environmental regulations and related topics, such as sustainability programs, associated with fossil fuel power plants.

Air Regulations
Solid/Hazardous Waste
Water Resources Protection
Spill Prevention, Control and Counter Measures
Pollution Prevention
Other Power Plant Resources


Air Regulations

Numerous existing standards and programs under the Clean Air Act may affect the fossil fuel electric power generation industry. These regulations and programs include:

The familiar National Ambient Air Quality Standards (40 CFR Part 50) do not directly affect the fossil fuel electric power generation industry because they are not applied to sources. Rather, these standards are applied to the ambient air in a particular area. Fossil fuel electric power generators may be indirectly affected by these standards if they are located in or near an area with nonattainment status. In meeting NAAQS, States develop and implement State Implementation Plans (SIPs) that prescribe use of reasonably available control technologies (RACTs) for major sources (control techniques for limiting emissions from existing sources in nonattainment areas; RACTs are adopted and implemented by states). In addition, as fossil fuel electric power generation facilities are typically one of the largest emitters of criteria pollutants, they may be targeted for more stringent controls implemented through operating permits.

Other existing or forthcoming rules that impact power plants include:

  • Clean Air Visibility Rule (2005) - These final amendments to EPA's 1999 Regional Haze Rule require emission controls for industrial facilities emitting air pollutants that reduce visibility.

  • The Regional Transport Rule (1998) reduces regional emissions of nitrogen oxides (NOx) in 22 states and the District of Columbia, and in turn, reduces the regional transport of ozone.

  • EPA's NOx SIP Call reduces the regional transport of ground-level ozone pollution in the East.

  • The forthcoming Clean Air Transport Rule (CATR) represents a court-mandated revision to the Clean Air Interstate Rule (CAIR) regulating sulfur dioxide (SO2 ) and nitrogen oxides (NOx) emissions under the Clean Air Act.

  • Forthcoming court-mandated Hazardous Air Pollutants (HAPs) Maximum Achievable Control Technology (MACT) rule will require coal- and oil-fired steam electric generating units to meet emissions limits for mercury (Hg) and other hazardous air pollutants (HAPs).

Additionally, Congress may move to establish a carbon cap-and-trade system to reduce GHG emissions from power plants. Absent Congressional pre-emption, EPA is developing guidance that will inform how States determine Best Available Control Technology (BACT, the most up-to-date methods, systems, techniques, and production processes available to achieve the greatest feasible emission reductions for given regulated air pollutants and processes), which may include provisions to encourage energy efficiency.

Recent Regulatory Activity
National Emission Standards for Hazardous Air Pollutants From Coal- and Oil-Fired Electric Utility Steam Generating Units and Standards of Performance for Fossil-Fuel-Fired Electric Utility (May. 5, 2011). On May 5, 2011 the U.S. Environmental Protection Agency proposed national emission standards for hazardous air pollutants (NESHAP) from coal- and oil-fired electric utility steam generating units (EGUs) under Clean Air Act (CAA or the Act) section 112(d) and revised new source performance standards (NSPS) for fossil fuel-fired EGUs under CAA section 111(b). The proposed NESHAP would protect air quality and promote public health by reducing emissions of the hazardous air pollutants (HAP) listed in CAA section 112(b). In addition, these proposed amendments to the NSPS are in response to a voluntary remand of a final rule. EPA is also proposing several minor amendments, technical clarifications, and corrections to existing NSPS provisions for fossil fuel-fired EGUs and large and small industrial-commercial-institutional steam generating units. The point of contact for the proposed regulations is Mr. William Maxwell, Energy Strategies Group, Sector Policies and Programs Division, (D243-01), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; Telephone number: (919) 541-5430; Fax number (919) 541-5450; E-mail address: maxwell.bill@epa.gov. The full text of the rule can be found at: Federal Register: May 3, 2011 [Proposed Rules] Pages 24976-25147.


Solid/Hazardous Waste

The primary solid waste releases from coal- and oil-fired steam electric facilities are fly ash and bottom ash produced during the combustion process. An increasing number of facilities must condition flue gases to remove sulfur compounds, which results in the generation of another solid waste typically referred to as FGD sludge.

Coal Combustion Residuals (CCR), often referred to as coal ash, are currently considered exempt wastes under an amendment to RCRA, the Resource Conservation and Recovery Act. On June 21, 2010 EPA proposed a new RCRA rule governing the disposal of coal combustion residuals (see: http://www.epa.gov/epawaste/nonhaz/industrial/special/fossil/ccr-rule/index.htm). With this rule, EPA is proposing to regulate for the first time coal ash to address the risks from the disposal of the wastes generated by electric utilities and independent power producers.


Water Resources Protection

Existing Effluent Regulations. Wastewater discharges from fossil fuel electric power generation facilities released to waters of the United States are covered under the Clean Water Act (CWA). Any point source discharge is required to apply for, and obtain, an NPDES permit (40 CFR Part 122). Permits may be issued by EPA or a State, depending upon whether the State has a delegated program. The NPDES permits serve to regulate point source discharges by establishing pollutant limitations and other special conditions. Facilities discharging to a POTW may be required to obtain a permit from a POTW that has an approved pretreatment program.

Current technology-based effluent limitations guidelines and pretreatment standards for discharges from the steam electric generating point source category were promulgated in 1982 (40 CFR 423).

In general, steam electric facilities built after 1982 are considered new sources and must comply with the 1982 effluent limitations. Less stringent guidelines may apply for facilities constructed between 1974 and 1982. Steam electric generating facilities that have been repowered are considered new sources.

Steam electric facilities that discharge to a POTW may be required to meet pretreatment standards for existing sources (PSES) or for new sources (PSNS). General pretreatment standards applying to most industries discharging to a POTW are described in 40 CFR Part 403. Pretreatment standards applying specifically to the steam electric generating point source category are listed in 40 CFR 423.16 and 17.

Beyond the applicable technology-based effluent limitations described above, permits may also establish technology-based limits for other pollutants based on the application of best professional judgment (BPJ). Permit limits and special conditions may also be established based on water quality considerations. Thermal limitations are often placed in permits for steam electric power plants based on Section 316(a) of the CWA and water quality considerations. Additionally, permits may require the performance of a demonstration study and implementation of control technologies to minimize adverse environmental impacts from cooling water intake structures.

Future Effluent Regulations. Based on the findings from EPA's multi-year study of the Steam Electric Power Generating industry, EPA plans to revise the current effluent guidelines for this industry. EPA's decision to revise the current effluent guidelines was announced on September 15, 2009 and is largely driven by the high level of toxic-weighted pollutant discharges from coal fired power plants and the expectation that these discharges will increase significantly in the next few years as new air pollution controls are installed. Over the course of the study, EPA identified technologies that can significantly reduce these pollutant discharges. See steam electric power generating industry study for more information.

Stormwater Regulations. Storm water discharges associated with any industrial activity onsite at a fossil fuel electric power generation facility are covered under the National Stormwater Program. Steam electric power generating activities are listed as one of the eleven categories of industrial activities subject to the storm water permit application requirements (category vii). The regulations at 40 CFR Part 122.26 require facilities discharging storm water from the eleven categories of industrial activities to apply for a stormwater permit if the stormwater discharges to waters of the United States. EPA has issued a Multi-Sector General Permit (MSGP) that addresses stormwater discharges from various sectors of industrial activity. The 2008 MSGP provides coverage for industrial facilities (see Appendix D of the 2008 MSGP) located in 5 States, and in certain Indian Country lands, as well as at various Federal Facilities in other States (see Appendix C of the 2008 MSGP, where EPA still remains the NPDES permit authority.

Most states are authorized to implement the Stormwater NPDES permitting program. In most permits, facilities are required to develop and implement a stormwater pollution prevention plan. However, limitations and other special conditions may be included on a case-by-case basis. Some permits may include the numeric effluent limitation guideline for coal pile runoff. Stormwater discharges associated with other industrial activities at fossil fuel electric power generation facilities are typically not subject to numeric limits, however.


Spill Prevention, Control and Counter Measures

EPA promulgated the Spill Prevention, Control and Counter Measures (SPCC) rule to reduce the risk of damaging our waterways from oil spills. These rules are applicable to a very wide rage of facilities and operations, including fuel oil storage tanks located at power plants. The rule requires specific facilities to prepare, amend, and implement SPCC Plans. The SPCC rule is part of the Oil Pollution Prevention regulation, which also includes the Facility Response Plan (FRP) rule.

Operations related to SPCC at these facilities include the transfer of oil for maintenance activities, the storage of fuel oil for powering generators during emergencies or for power plant startup, and the storage of insulation (dielectric) oil in electrical equipment (e.g., transformers, oil circuit breakers, capacitors, regulators). Some facilities are moving towards using sulfur hexafluoride (SF6) gas for insulating circuit breakers. These circuit breakers do not contain oil for insulation purposes, but they do contain small amounts (e.g., two gallons) of compressor oil

An SPCC Plan is required for facilities which due to their location, could reasonably be expected to discharge oil to surface water or adjoining shorelines and have:

  • Total aboveground storage capacity of 1,320 gallons or more of oil (however, only containers or oil-containing equipment with a capacity equal to or greater than 55 gallons count toward the threshold); or

  • A total oil underground storage capacity of 42,000 gallons or more (however, underground storage tanks subject to regulation under RCRA [40 CFR 280 or 281] are not included); or

  • Been required by the EPA to prepare and implement an SPCC Plan.

The SPCC regulations require the facility owner/operator to prepare and implement an SPCC plan for their facility. This plan must be well thought out and prepared in accordance with good engineering practices. It must document the location of storage vessels, types of containment, dangers associated with a major release of material from the tanks, types of emergency equipment available at each site, and procedures for notifying the appropriate regulatory and emergency agencies.

Many power-generating facilities are located adjacent to or over water; so if their aggregate storage (including oil-filled electrical equipment, fixed and mobile storage tanks, etc.) is more than one million gallons, they are likely to be subject to the Facility Response Plan (FRP) requirements as well (40 CFR 112.20). These facilities are likely to be required to prepare an FRP because a discharge from the facility has a high potential to cause injury to an environmentally sensitive area or shut down a public drinking water intake.

More resources on SPCC:

To assist facility owners and operators with SPCC compliance, EPA has published:


Pollution Prevention

The following programs and initiatives are aimed at reducing environmental impacts of power plants:

  • EPA's Green Power Partnership. Voluntary program that supports the organizational procurement of green power by offering expert advice, technical support, tools and resources. Green power is electricity produced from a subset of renewable resources, such as solar, wind, geothermal, biomass, and low-impact hydro. Also see Sector Notebook (section V).

  • Combined Heat and Power Partnership: A voluntary program seeking to reduce the environmental impact of power generation by promoting the use of CHP (cogeneration).

  • Other Clean Energy Programs (including state programs): http://www.epa.gov/cleanenergy.

  • Potential beneficial use of coal combustion products includes, but is not restricted to, raw feed for cement clinker, concrete, grout, flowable fill, structural fill, road base/sub-base, soil-modification, mineral filler, snow and ice traction control, blasting grit and abrasives, roofing granules, mining applications, wallboard, waste stabilization/solidification, soil amendment, and agriculture. See: http://www.epa.gov/wastes/conserve/rrr/imr/ccps/index.htm.


Other Power Plant Resources

Applicability Tool. This tool is designed to help you assess whether your facility would be required to report greenhouse gas (GHG) emissions as required by EPA's Mandatory GHG Reporting Rule.

Profile of the Fossil Fuel Electric Power Generation Industry, EPA Sector Notebook (1997). The Sector Notebook Project was originally initiated by the Office of Compliance within the Office of Enforcement and Compliance Assurance (OECA) to provide its staff and managers with summary information for 18 specific industrial sectors.