The U.S. Environmental Protection Agency on Friday issued a final rule on nitrogen oxide standards for new gas-fired power plants and other stationary turbines. The standards are significantly more lenient than a proposal issued in November during the Biden administration.
The EPA determined that the “best systems of emissions reduction,” or BSER, for NOx emissions is the continued use of combustion controls for all but one subcategory of new, modified or reconstructed turbines. The BSER for new large turbines with 12-month capacity factors over 45% is combustion controls combined with post-combustion selective catalytic reduction, or SCR.
In November, the Biden EPA proposed finding that for most combustion turbines, the use of combustion controls plus SCR is the BSER.
The EPA estimated its final new source performance standards for stationary combustion turbines will cut annual NOx emissions by up to 296 tons by 2032 — significantly less than the 2,659 tons the proposed rule was estimated to cut.
The new standards cover facilities that started construction, modification or reconstruction after Dec. 13, 2024. The standards were last updated in 2006.
NOx contributes to asthma, bronchitis, respiratory infections and premature mortality by reacting with other volatile organic compounds to form ozone and fine particulate matter, according to the EPA.
The standards come amid a surge in proposed gas-fired power plants across the United States, in part driven by rising electric demand forecasts from data centers. The PJM Interconnection, for example, has approved about 8.1 GW of gas-fired capacity for fast-track interconnection review. The Midcontinent Independent System Operator has approved or is reviewing about 9.2 GW of gas-fired generation in its fast-track interconnection process and the Southwest Power Pool is studying about 9.6 GW of gas-fired capacity in its similar interconnection review.
The EPA estimated that the final rule will save power plant owners $87 million over eight years. The savings come from combining the cost to power plants that will have more-stringent standards to the savings from those that will have less-stringent standards, the EPA said in a fact sheet.
The agency expected its proposed rule would have cost $166 million in the same period, but it would have provided net benefits of up to $340 million, partly through improved public health.
EPA drops health benefits analysis
In a change from agency practice, the EPA declined to estimate the monetary benefits of improved public health caused by the final rule, saying those estimates are too uncertain.
“Because of the significant impacts of environmental regulations on the U.S. economy, it is essential that the Agency have confidence in the estimated benefits of an action prior to utilizing these estimates in a regulatory context,” the EPA said in its economic impact analysis of the final rule.
Groups criticized the EPA’s decision to stop considering the health benefits of reduced pollution in its regulatory analysis.
“Communities across the country are scrambling to fight the threat of surging pollution harms from new fossil gas plants built to meet insatiable data center electricity demand,” Julie McNamara, associate policy director of the Union of Concerned Scientists’ Climate and Energy Program, said in a statement Monday. “Instead of protecting people’s health, however, these deficient new gas turbine standards make clear Trump’s EPA is only here to boost the profits of Big Tech and the fossil fuel interests that serve them.”
The EPA’s failure to assess the monetary benefits from saving lives and improving people’s health by curbing fine particulate matter and ozone may be challenged in court, according to Public Citizen, a consumer watchdog group.
EPA’s analyses have shown trillions of dollars of economic benefits from protecting public health and welfare under the Clean Air Act, according to John Walke, a senior attorney at the Natural Resources Defense Council.
“These benefits came from strong health protections that vastly outweigh polluter compliance costs,” he said in a statement.
