The U.S. Environmental Protection Agency (EPA) has issued a final rule setting standards and guidelines to control aircraft deicing effluents. The rule leaves requirements for existing airports to be determined on a case-by-case basis through permitting procedures. Issued by EPA under the Clean Water Act, the rule requires that area-based pavement deicers be avoided or minimized at existing and new primary airports with 1,000 or more annual jet departures. It also sets a new source performance standard that requires new airports with 10,000 annual departures in cold climates to collect 60 percent of aircraft deicing fluid. New airports that discharge the collected deicing fluid directly to waters of the United States must also meet numeric discharge requirements for pollutants. The rule will be effective 30 days after it is published in the Federal Register.