In late April, the U.S. Environmental Protection Agency (EPA) announced four final rules designed to reduce pollution from fossil fuel-fired power plants. These rules were finalized under separate authorities, including the Clean Air Act, Clean Water Act, and Resource Conservation and Recovery Act.

By announcing these final rules at the same time, EPA is following through on its commitment in 2022 to provide regulatory certainty as the power sector makes long-term investments in the transition to a clean energy economy. The rules are designed to work with the power sector’s planning processes, providing compliance timelines that enable power companies to plan in advance to meet electricity demand while reducing dangerous pollution.

There are four final rules:

1 – A final rule for existing coal-fired and new natural gas-fired power plants that would ensure that all coal-fired plants that plan to run in the long-term and all new baseload gas-fired plants control 90 percent of their carbon pollution.

2 – A final rule strengthening and updating the Mercury and Air Toxics Standards (MATS) for coal-fired power plants, tightening the emissions standard for toxic metals by 67 percent and finalizing a 70 percent reduction in the emissions standard for mercury from existing lignite-fired sources.

3 – A final rule to reduce pollutants discharged through wastewater from coal-fired power plants by more than 660 million pounds per year, ensuring cleaner water for affected communities, including communities with environmental justice concerns that are disproportionately impacted.

4 – A final rule that will require the safe management of coal ash that is placed in areas that were unregulated at the federal level until now, including at previously used disposal areas that may leak and contaminate groundwater.

According to the EPA, with its recent announcement, the power sector can make planning decisions with a full array of information. “In fact, the agency’s analysis indicates that issuing these rules at the same time is likely to create more efficiency for facilities that are now able to evaluate compliance steps together rather than only for each rule in isolation,” said the EPA. Therefore, adding the cost of the rules modeled independently would likely reflect an overestimate of total costs.

 

1 – Stronger Carbon Pollution Standards for New Gas and Existing Coal Power Plants

EPA’s final Clean Air Act standards for existing coal-fired and new natural gas-fired power plants limit the amount of carbon pollution that covered sources can emit, based on proven and cost-effective control technologies that can be applied directly to power plants. The regulatory

impact analysis projects reductions of 1.38 billion metric tons of carbon pollution overall through 2047.

The rule addresses existing coal-fired power plants, which continue to be the largest source of greenhouse gas emissions from the power sector, and ensures that new natural gas combustion turbines, some of the largest new sources of greenhouse gases being built today, are designed using modern technologies to reduce climate pollution.

These final emission standards and guidelines will achieve substantial reductions in carbon pollution at reasonable cost. The best system of emission reduction for the longest-running existing coal units and most heavily utilized new gas turbines is based on carbon capture and sequestration/storage (CCS) – an available and cost-reasonable emission control technology that can be applied directly to power plants and can reduce 90 percent of carbon dioxide emissions from the plants.

Lower costs and continued improvements in CCS technology, alongside tax incentives from the federal government’s Inflation Reduction Act that allow companies to largely offset the cost of CCS, represent recent developments in emissions controls that informed EPA’s determination of what is technically feasible and cost-reasonable. The Bipartisan Infrastructure Law also includes billions of dollars to advance and deploy CCS technology and infrastructure. As a result, EPA projects that the sector can comply with the standards with negligible impact on electricity prices, thanks to cost declines in CCS and other emissions-reducing technologies. EPA analysis also finds that power companies can comply with the standards while meeting grid reliability, even when considering increased load growth.

 

2 – Strengthening Mercury and Air Toxics Standards

EPA is strengthening and updating the Mercury and Air Toxics Standards (MATS) for coal-fired power plants, achieving important hazardous air pollutant (HAP) emissions reductions and ensuring that the standards reflect the latest advancement in pollution control technologies. This final rule under the Clean Air Act is the most significant update since MATS was first issued in February 2012, building on highly successful and cost-effective protections.

EPA projects the final rule will reduce emissions of mercury and non-mercury metal HAPs, such as nickel, arsenic, and lead.

The final rule reduces the mercury emissions limit by 70 percent for lignite-fired units and reduces the emissions limit that controls for toxic metals by 67 percent for all coal plants—while also requiring the use of continuous emission monitoring systems to provide real-time, accurate data to regulators, facility operators, and the public to ensure that plants are meeting these lower limits and that communities are protected year-round from pollution exposure.

 

3 – Stronger Limits on Water Pollution from Power Plants

EPA is strengthening wastewater discharge standards that apply to coal-fired power plants, finalizing a rule that follows the latest science and applies EPA’s longstanding authority under the Clean Water Act to reduce discharges of toxic metals and other pollutants from these power plants into lakes, streams, and other water bodies.

“Power plants that burn coal to create electricity use large volumes of water,” said the EPA. “When this water is returned to lakes, streams, and other waterbodies, it can carry pollutants, including mercury, arsenic, selenium, nickel, bromide, chloride, iodide, and nutrient pollution.”

EPA’s final rule here establishes technology-based discharge standards (known as Effluent Limitation Guidelines (ELGs)), that will apply to four types of wastewater:

– Flue gas desulfurization wastewater

– Bottom ash transport water

– Combustion residual leachate

– “Legacy wastewater” that is stored in surface impoundments (for example, coal ash ponds).

The rule includes implementation flexibilities for power plants. For example, the final rule creates a new compliance path for electricity generating units that permanently stop burning coal by 2034. These units will be able to continue meeting existing requirements, instead of the requirements contained in this final regulation. In a separate action finalized last year, EPA updated but maintained an existing provision allowing units to comply with less stringent standards if they will permanently stop burning coal by 2028.

Following its analysis, EPA has determined that this final rule will have minimal effects on electricity prices.

 

4 – Latest Action to Protect Communities from Coal Ash Contamination

Under the Resource Conservation and Recovery Act, EPA is finalizing a rule to protect communities and hold polluters accountable for controlling and cleaning up the contamination created by the disposal of coal combustion residuals (CCR or coal ash).

EPA’s final rule expands protections for the communities and ecosystems near active and inactive coal burning power plants, ensuring that groundwater contamination, surface water contamination, fugitive dust, floods and impoundment overflows, and threats to wildlife are all addressed.

To address these concerns, EPA established safeguards for legacy coal ash surface impoundments that largely mirror those for inactive impoundments at active facilities, including requiring the proper closure of the impoundments and remediating coal ash contamination in groundwater. EPA analysis shows that the final rule will reduce existing disproportionate and adverse effects on communities with environmental justice concerns.

In addition, through implementation of the 2015 CCR rule, EPA found “historic” disposal units that are leaking and contaminating groundwater at currently regulated power plants, but which

were exempt under the original 2015 regulations. These are areas where coal ash was placed directly on the land, such as coal ash in surface impoundments and landfills that closed prior to the effective date of the 2015 CCR Rule and inactive CCR landfills. This final rule extends a subset of EPA’s existing CCR requirements to these historic disposal units that will ensure that any contamination from these areas is remediated, and will prevent further contamination. These requirements will apply to all active CCR facilities and inactive facilities with legacy CCR surface impoundments.

EPA does not expect this rule to affect the current operations of power plants, and therefore anticipates no impacts to electricity generation or grid reliability.