- The Environmental Protection Agency on Thursday announced it is loosening pollution control requirements for major sources of hazardous emissions such as mercury and lead.
- In a memo, the head of the EPA Air Office said the agency would rescind the "once in, always in" policy under the Clean Air Act that made major pollution sources subject to tougher emission control standards. Companies will now be able to escape the tougher standards if they take steps to cut pollution.
- The EPA last tried to rescind the "once in, always in" policy during the George W. Bush administration, but its efforts were blocked by Congress after leaked memos showed regional EPA staff critical of the idea. Environmental groups decried the EPA's move, saying it could lead to huge increases in air pollution.
Established by EPA guidance in 1995, backers of the "once in, always in" policy under section 112 of the Clean Air Act say it is a critical provision for reducing some of the most harmful air pollutants.
Under the policy, pollution sources like power plants or industrial facilities that emit more than 10 tons annually of one pollutant or 25 tons annually of a group of pollutants are required to deploy the Maximum Available Control Technology (MACT) available to plant owners to cut emissions. The regulation covers more than 200 pollutants including lead, mercury, dioxins and arsenic.
Under the "once in" policy, when a pollution source is shown to cross those emission thresholds, it would be permanently subject to the MACT standard. MACT is a tougher and more expensive pollution control standard than others under the Clean Air Act, and plant owners argue the policy removed an incentive for facilities to cut pollution.
In a Thursday memo, William Wherum, head of the EPA Air Office, rescinded the guidance, writing that a plant that takes steps to limit pollution will now be able to be redefined under the less-stringent definition of an "area source."
"EPA has now determined that a major source which takes on an enforceable limit on its [potential pollution] and takes measures to bring its [hazardous pollution] below the applicable threshold becomes an area source, no matter when the source may choose to take measures to limit its [potential emissions]," Wherum wrote.
"That source, now having area source status, will not be subject thereafter to those reporting requirements applicable to the source as a major source under [Clean Air Act] section 112, including, in particular, major source MACT standards — so long as the source's [potential emission level] remains below the applicable [hazardous pollution] thresholds."
The move is a victory for generators and industrial plant owners, as well as their allies in Congress. Sens. John Barrasso (R-WY) and Shelley Moore Capito (R-WV) previously wrote to the EPA asking it to loosen the MACT requirements.
Environmentalists, however, said rescinding the "once in" policy could create a loophole for plants to continue emitting dangerous pollutants hazardous to public health.
“This is among the most dangerous actions that the Trump EPA has taken yet against public health,” John Walke, the clean air director at the Natural Resources Defense Council, said in a statement. “This move drastically weakens protective limits on air pollutants like arsenic, lead, mercury and other toxins that cause cancer, brain damage, infertility, developmental problems and even death."