Sen. Shelley Moore Capito's bill to scuttle U.S. EPA's power plant carbon rules would also severely restrict the scope of any replacement rules, the Congressional Budget Office said yesterday.

The West Virginia Republican's bill, S. 1324, would kill the Clean Power Plan by allowing states to opt out of compliance at will without fear that a federal implementation plan would be constructed to take its place, the CBO report noted. It also would require the agency to set aside rules for new and modified facilities that were final in August and that together make up the core of President Obama's second-term Climate Action Plan.

While the measure would allow the agency to put forward rules to take their place -- and CBO assumes that EPA would do so -- it's not clear that those rules could require technology that differs from a business-as-usual scenario. Rules for existing plants could not be promulgated until EPA makes a report to Congress on their climate and economic effects and issues state-specific plans.

A separate provision of the bill, which CBO does not mention, would bar EPA from regulating under Section 111(d) of the Clean Air Act at all if it has already done so under Section 112, effectively codifying in law a legal objection often raised by opponents of the Clean Air Act that will figure in coming litigation. EPA's 2011 mercury and air toxics rule is written under Section 112.

Rules for new and modified facilities must be based "on actual emissions levels achieved by at least six different electric generating units across the United States when operating for a continuous 12-month period." So, in effect, they couldn't go beyond the current state-of-the-art technology for newly built coal and natural gas generation.

The report acknowledges that the Capito measure "would not prohibit EPA from continuing to work on activities related to power plants, such as developing guidance and providing technical assistance to states." But David Doniger, director of the climate and clean air program at the Natural Resources Defense Council, said it would dramatically change EPA's regulatory authority.

"It's basically saying that instead of being a plumber that comes to your home and fixes your pipes, [EPA is] now allowed to give you advice over the phone," he said.

The Environment and Public Works Committee approved the Capito bill in August, and Senate Majority Leader Mitch McConnell (R-Ky.) has expressed his support. It tracks with his strategy of persuading state governors to "just say no" to implementing EPA's rule.

But while the House has passed roughly similar legislation, it remains unclear whether McConnell will make room for Capito's bill in a busy fall legislative schedule -- especially as it seems unlikely it would garner the 60 votes needed to pass.

Instead, McConnell and Environment and Public Works Chairman James Inhofe (R-Okla.) are readying Congressional Review Act resolutions for after EPA publishes the new and existing power plant rules in the Federal Register. They could pass the Senate with a simple majority of the vote, and while they would not be expected to withstand a presidential veto, McConnell hopes they would show the world ahead of this year's climate talks in Paris that Congress is not united behind Obama's climate pledges.

Doniger criticized Republicans for seeking to undermine global confidence in the U.S. pledge.

"The Republicans spent more than a decade arguing that we shouldn't act alone because other countries are unreliable, now they're arguing that they shouldn't act because we're unreliable," he said.