On July 21, the National Petrochemical and Refiners Association and the American Petroleum Institute petitioned the U.S. Supreme Court to decide whether a federal agency that misses a statutory rulemaking deadline can apply a regulation retroactively based on implicit, not actual, congressional authorization. The primary rule at issue is an EPA rule implementing a renewable fuel standard that took effect July 1, 2010, but stretched back to cover all of 2010. The rule was originally slated for 2008, but was delayed until 2010. In December 2010, the U.S. Court of Appeals for the District of Columbia Circuit rejected a challenge to the regulation by the same two groups.