The EPA is trying to reassure state energy regulators that the upcoming rule to reduce greenhouse gas emissions from existing power plants would give states flexibility.

The regulation, which is part of President Obama's climate change agenda, requires states to develop plans to reduce greenhouse gas emissions from power plants but “will give them discretion over how to reach those goals,” according to the EPA.

The National Association of Regulatory Utility Commissioners (NARUC) said states need to be given leeway in how they reduce emissions due to different geographic considerations, climates, mixes of energy sources, and budgets.

EPA Chief Gina McCarthy said the final rule is likely to take those factors into account. “There is enormous flexibility in the definition of a state plan and our ability to look at a timeline for achieving that, for submitting the plan, and for achieving the reductions.”