A federal judge ordered the EPA to complete a long overdue report on air pollution caused by cars, calling the agency's failure remarkable, given Congress' express intent in passing the Clean Air Act: to "accelerate national research to achieve control of air pollution."

The EPA is supposed to study the effects of carbon monoxide, a principal product of gas engines, every five years. But is has failed to conduct such a study since 1994.

The ruling is the latest in a string of government defeats on environmental issues. U.S. District Judge Jeffrey White gave the EPA until 2011 to review air quality criteria and national ambient air quality standards for carbon monoxide and set interim deadlines to ensure the EPA does its job.

Four environmental groups led by Communities for a Better Environment sued the EPA under the Clean Air Act for neglecting its statutory duty to review and, if appropriate, revise air quality standards for carbon monoxide, which it has not done since 1994 though it is required to do so every five years.

Judge White rejected the EPA's argument that so long as it finishes the review within five years of being sued, it need only set a "reasonable" schedule at this time. Judge White pointed out that the statutory timeframe began in 1990 and re-occurs every five years. White also concluded that the court may exercise its authority "to set enforceable deadlines both of an ultimate and an intermediate nature" when an agency fails to meet a statutory deadline.

According to the ruling, the EPA's failure to conduct the review is especially remarkable considering one of Congress' express purposes in enacting the Clean Air Act was to "accelerate a national research and development program to achieve the prevention and control of air pollution."

On the other hand, White conceded that public interest would not be served by moving up the deadline so much that a full review would be impossible, arguing that "courts should not impose an infeasible schedule upon an agency in order to punish the agency for its delinquency."

White ruled that the EPA's argument that the court can only issue an order requiring the agency to comply with the ultimate deadline for review incorrectly attempts to limit the court's authority.