Ten environmental groups have filed a lawsuit against the Trump administration, arguing its rules for addressing power plant pollution are insufficient to the point they violate federal law.

The suit filed Wednesday comes a day after 22 states and several cities filed a similar lawsuit, arguing the new rule violates the Clean Air Act by having nearly no impact on carbon emissions.

The Environmental Protection Agency (EPA) had finalized the rule in June to repeal and replace a capstone Obama-era carbon pollution regulation they say exceeded agency authority.

The new rule, called the Affordable Clean Energy (ACE) rule, would replace the Clean Power Plan (CPP). The Trump administration rule aims to give states more time and authority to decide how to implement the best new technology to ease net emissions from coal-fired plants. ADVERTISEMENT

“We will challenge every part of this misguided rule, which has already been broadly denounced by the medical, environmental, and legal communities as a poorly constructed band-aid for the coal industry’s economic woes,” the Sierra Club, one of the parties in the suit, said in a statement.

States and environmental groups have long said they would challenge the ACE in court, arguing it does so little to curb pollution it cannot be considered a serious regulation. Many environmental groups point to analysis showing Trump’s rule will actually increase pollution.

The Trump administration rule does not set a specific carbon reduction target for states, and it is narrowly tailored to deal with physical changes that can be made at power plants rather than broader regulatory solutions that could be imposed by states.

“Power plants can run less frequently, less intensely; there can be renewable generation that fills up the gaps,” Andres Restrepo, a lawyer with the Sierra Club, said of potential alternative measures when ACE was first announced.

The legal battle will largely boil down to how much action the Clean Air Act requires of the EPA. A decision could have major consequences, as a win for the agency could stymie future administrations from addressing climate change.

“What they want is a court ruling that says the best system of emission reduction is limited to these tiny minor tweaks that do nothing, and then the EPA can do nothing going forward to address pollution,” Lissa Lynch, an attorney with the Natural Resources Defense Council (NRDC), one of the parties in the suit, said when the rule was first unveiled. “That’s what the EPA wants.”

The EPA did not immediately respond to a request for comment.

The agency argued when first rolling out the new rule this year that the Obama-era regulations that remain tied up in court had gone beyond requiring the best new technology to ease net emissions from coal-fired plants.

“Under the CPP, the EPA [under the] Obama administration went beyond implementing best technology,” a senior EPA official said when announcing the regulations. “Under the CPP the Obama administration actually imposed emissions reductions on each and every state. We don’t believe that’s an EPA role or authority under the [Clean Air Act].”

In addition to the Sierra Club and the NRDC, the Environmental Defense Fund, the Center for Biological Diversity and others are party to the suit filed Wednesday.