The US Environmental Protection Agency (EPA) today finalized a suite of rules affecting coal-fired power plants.
In addition to imposing more stringent CO2 emissions limits on coal-fired power plants, the agency tightened some mercury and air toxics standards, imposed new limits on waste water discharges from coal-fired plants and set new requirements for managing inactive coal ash depositories.
"By developing these standards in a clear, transparent, inclusive manner, EPA is cutting pollution while ensuring that power companies can make smart investments and continue to deliver reliable electricity for all Americans," EPA Administrator Michael Regan said.
EPA's new CO2 rules would require coal-fired power plants staying open beyond 2039 to reduce or capture 90pc of carbon emissions by 2032, with other requirements for plants running after 1 January 2032 but retiring by 2039. EPA also is tightening its mercury and air toxics standards, lowering the emissions limit for filterable particulate matter by 67pc and requiring power plants burning lignite coal to reduce mercury emissions by 70pc.
The finalized revisions to EPA's effluent limitations requires all coal plants retiring after 2034 to retrofit facilities with best available technology to eliminate all pollutants in flue gas desulfurization waste water, bottom ash transport water, and combustion residual leachate by 31 December 2029. It also sets a numeric limit on mercury and arsenic in unmanaged combustion residual leachate from surface impoundments through groundwater if the impoundments are not in the process of closing by the time the rule takes effect.
In addition, the revised effluent standards removes less stringent best available technology requirements for high-flow facilities and low-utilization generating units, an option that had been available since 2020.
Plants retiring between 2029 and 2034 would be allowed to continue meeting existing effluent requirements, while those retiring by 2028 have less stringent standards that were finalized last year.
The new agency standards also will apply to so-called "legacy" waste waters that are stored in surface impoundments.
EPA expects the new waste water standards to prevent about 660mn pounds/yr of pollutants from being discharged in power plant waste water once the rule is implemented. That is more than what the agency projected in the preferred scenario of its proposal last year.
In addition, EPA finalized revisions to its Coal Combustion Residual rule to require owners and operators of inactive surface impoundments at retired coal plants to comply with similar regulations already imposed on closed sites at otherwise active facilities. EPA also expanded the rule's reach to include certain "historic" impoundments that had been exempt from the initial 2015 coal ash rule but have since been found to be leaking.
The new emissions and waste water rules are likely to face challenges from the coal industry. Some organizations have already warned that the rules will cause greater stress on coal plant operators as well as to electric grids and reliability. The Edison Electric Institute raised concerns about the CO2 limits potentially forcing coal plant operators to use carbon capture sequestration by 2032 given that that technology "is not yet ready for full-scale, economy-wide deployment, nor is there sufficient time to permit, finance, and build" infrastructure needed to bring power plants into compliance, chief executive Dan Brouillette said.
The National Mining Association (NMA) threatened to sue EPA over its new rules.
"We've seen this unlawful regulatory playbook before, challenged it and the Supreme Court agreed with our take," NMA chief executive Rich Nolan said. "We will do so again and expect the same outcome."
The EPA said its finalized rules comply with the law. In addition, the US Energy Department is finalizing rules aimed at speeding up upgrades to, and installation of, transmission lines to support transitions in electricity generation.
