This suite of rules includes two final rules promulgated under the Clean Air Act, one promulgated under the Clean Water Act, and one promulgated under the Resource Conversation Act, each aiming to regulate primarily coal-fired power plants’ discharges, emissions, and general operations. EPA hopes that its new standards were appropriately “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.” Those compliance timelines begin soon and impact the following operations of coal fired power plants.
New Source Performance Standards Amendment Aimed at Reducing Carbon
EPA’s final New Source Performance Standards for existing coal-fired and new natural gas-fired power plants limit the amount of carbon a covered source can emit. Specifically, the standards require that all coal-fired plants that plan to operate after 2039 and all new baseload gas-fired plants control 90% of their carbon emissions. EPA indicates that carbon capture and sequestration (CCS) is the best system of emission reduction (BSER) to meet the stringent carbon control requirements promulgated in the new rule. To comply, coal-fired plants that plan to operate past 2039 and all new baseload gas-fired plants must meet EPA’s BSER by implementing a CCS with 90% carbon reduction by January 1, 2032. For coal-fired power plants that intend to permanently cease operation before 2039, EPA has instituted a BSER of co-firing with natural gas, which presumptively will result in a 16% reduction in annual emissions rates. Coal-fired powered plants in this subcategory must comply with the instituted BSER by January 1, 2030.
National Emission Standards for Toxic Metals and Mercury
EPA’s final Mercury and Air Toxic Standards for coal-fired power plants tightens emissions standards for certain metals — such as nickel, arsenic, and lead — from all coal-fired sources and mercury from existing lignite-fired sources. Specifically, the rule reduces the mercury emissions limit by 70% for lignite-fired units and reduces the emissions limit for toxic metals by 67% for all coal-fired plants. The updated standards also require the use of continuous emission monitoring systems to provide real-time, accurate data to regulators, facility operators, and the public. Compliance with these revised standards must be achieved by three years after the effective date of the rule, which is 60 days after the rule is published in the federal register.
Supplemental Effluent Limitation Guidelines and Standards for Wastewater Discharge
EPA’s final Steam Electric Power Generating Effluent Limitation Guidelines significantly tighten wastewater discharge standards applicable to several wastewater streams at many existing coal-fired power plants. Specifically, the rule establishes new zero discharge limits (ZDL) for most pollutants within three types of wastewater:
- Flue gas desulfurization wastewater.
- Bottom ash transport water.
- Combustion residual leachate.
Additionally, the rule imposes mercury and arsenic effluent limits for discharges of “legacy wastewater,” a newly classified waste stream that includes wastewater stored in surface impoundments that have not yet commenced closure under 40 C.F.R. Part 257. Subpart D. The term is also defined to include certain groundwaters.
Facilities required to meet these updated guidelines must do so by December 31, 2029. The final rule does provide a facility subcategory for coal-fired plants that intend to permanently cease operation by 2034 that allows such plants to avoid the need to meet the updated guidelines. The rule also eliminates less stringent requirements for high flow facilities and low utilization energy generating units which were imposed in 2020.
Legacy CCR Surface Impoundment and CCR Management Units Rule
EPA’s Legacy CCR Surface Impoundment and CCRMU Rule amends the existing rules governing the disposal of coal combustion residuals (CCR) in landfills and surface impoundments, 40 C.F.R. Part 257. Subpart D, by regulating two new types of “units”: Legacy CCR Surface Impoundments and CCR management units (CCRMU). Under the new rule, EPA regulates inactive surface impoundments at inactive facilities — Legacy CCR Surface Impoundments — and coal ash disposed in areas outside of regulated units, including certain previously closed surface impoundments and landfills — CCRMUs.
The Legacy CCR Surface Impoundment and CCRMU Rule becomes effective six months after it is published in the federal register. Following its effective date, compliance timelines quickly approach, including the following deadlines for Legacy CCR Surface Impoundments: three months to complete an initial inspection; 14 months to complete an initial annual fugitive dust report; 15 months to compile a history of construction; and 18 months to complete initial assessments, prepare an emergency action plan, and complete an initial inflow design flood control system plan, among other deadlines. For CCRMUs, the compliance timelines will similarly approach quickly, including 15 months to establish a website and complete Part 1 of the facility evaluation report, 27 months to complete Part 2 of the facility evaluation report, and 42 months to install a groundwater monitoring system, develop a groundwater sampling and analysis program, and initiate detection and assessment monitoring, among other deadlines.