Discharge of De-Icing Agents from Airports to Nearby Water Recipients in Relation to the Water Framework Directive

Discharge of oxygen demanding substances like glycol, formate, acetate or ammonium may give anaerobic conditions, water with unpleasant odour/taste and appearance, as well as bacterial growth. Fish and bottom fauna may be negatively affected. Formate has the lowest oxygen demand, and will therefore be the most environmental friendly runway de-icing agent. Additives in de-icing agents may have a negative effect on the organisms living in the recipients. The only additive of environmental concern in the de-icing products used at Oslo Airport is an alcohol ethoxylate. This substance is ready biodegradable, probably not bioaccumulating, but is very toxic to aquatic organisms. An environmental risk assessment of the discharge water from the Oslo Airport concluded that the discharge would not be acute toxic for algae or crustacean in the water recipient. Appropriate monitoring of the concentration of glycol and organic matter in the recipient was, however, necessary to prevent deterioration of the water.