The D.C. Circuit Court of Appeals has told the Environmental Protection Agency (EPA) to rewrite rules meant to govern pollution emissions that drift across state lines.
The court ruled Tuesday that the EPA’s 2011 regulations on cross-state sulfur dioxide and ozone emissions are too broad and need to be rewritten.
The court did not vacate the emissions budgets the agency had set for states, but asked the EPA to reconsider them instead.
In 2011, the EPA released its Cross-State Air Pollution Rule, a regulation blocking up-wind states from emitting enough air pollutants to drift into neighboring states and put them out of compliance with EPA pollution standards.
Several states challenged the rule, arguing that the EPA had exceeded its authority by issuing uniform pollution standards for up-wind states rather than those based on how many pollutants each state actually releases.
The Supreme Court upheld the EPA’s basic formulation of the rule last year, but remanded specific state challenges to the D.C. Circuit Court. Judges there considered challenges to emissions budgets as applied in 15 states and decided that the EPA had overstepped it bounds in issuing the rule.
“EPA’s uniform cost thresholds have required states to reduce pollutants beyond the point necessary” to keep down-wind states in compliance with pollution rules, Circuit Court Judge Brett Kavanaugh wrote. “That violates the Supreme Court’s clear mandate.”
The judges decided to keep the EPA’s rules in place but ordered the agency to rewrite the regulations for states that took issue with them. They also rejected broader challenges to the legality of the rule as a whole.
In a statement, an EPA spokeswoman said the agency is "pleased" that the court upheld the bulk of the rule.
"The agency remains committed to working with states and the power sector as we move forward to implement the rule," spokeswoman Melissa Harrison said. "We are reviewing the decision and will determine any appropriate further course of action once our review is complete."
This story was updated at 3:00 p.m.