The core requirement in EPA’s new final effluent limitations guidelines (ELG) affecting pavement and aircraft deicing at existing primary airports is replacement of urea-containing airfield deicers with non-urea alternatives.
Primary commercial service airports are those that have more than 10,000 passenger boardings each year. Those airports will be required to certify the use non-urea airfield deicers. Alternatively, the airport can choose to meet a numeric effluent limit of 14.7 mg/L of ammonia as nitrogen. Pavement deicers containing urea degrade to ammonia and also generate biological oxygen demand (BOD5) and chemical oxygen demand (COD). Deicing wastewater discharges containing these contaminants have impaired both aquatic community health and human uses of water resources.
The urea-substitution requirement is not expected to have a major impact since, according to EPA, only about 10 percent of chemical pavement deicers applied nationwide contain urea. The most widely used pavement deicer is potassium acetate, which represents 63 percent of all chemical pavement deicers applied nationwide. EPA therefore determined that use of deicers without urea is the best available technology for reducing discharges of ammonia from pavement deicing because it is safe, technologically feasible, and available across the industry.
The rule does not establish requirements for aircraft deicing discharges at existing airports. Such requirements will continue to be established in general permits or on a site-specific basis in individual permits. For individual permits, permit writers will use best professional judgment to establish requirements for the collection and treatment of airport deicing fluid. EPA identified 31 pollutants of concern that stem directly from airport deicing operations.
Also under the rule, new airports with 10,000 annual departures, which are located in certain cold climate zones, must collect 60 percent of aircraft deicing fluid after deicing. New airports that discharge the collected aircraft deicing fluid directly to waters of the U.S. must also meet numeric discharge requirements for COD; specifically, a daily COD limit of 271 mg/L and a weekly maximum average of 154 mg/L. The limitation must be met at the location where the effluent leaves the onsite treatment system and before commingling with any non-deicing discharge. New airports in Alaska are exempted from the requirement; Alaskan airports will still be subject to applicable new source performance standards established on a case-by-case basis by permit writers.
In a joint statement, Airlines for America, Airports Council International - North America, the American Association of Airport Executives, and the Regional Airline Association commended EPA’s action. The organizations stated:
“[EPA’s ELGs] set technology-based standards designed to reduce discharges related to pavement deicing and aircraft deicing at new airports built after the rule goes into effect. The EPA further supported the industry’s voluntary pollution-reduction program, heralding its ‘potential to significantly reduce aircraft deicing discharges in a safe manner.’ As such, the agency further agreed that applying such standards to aircraft deicing at existing airports would be impracticable and deliver few benefits.”
EPA’s final ELGs and new source performance standards for the airport deicing category were published in the May 16, 2012, FR.