The design & operation of a very large vertical sub-surface flow engineered wetland to treat spent deicing fluids and glycol-contaminated stormwater at Buffalo Niagara International Airport

An advanced type of constructed wetland (CW) called an engineered wetland (EW) has been developed which allows more efficient removals of contaminants from wastewaters and stormwaters at rates in many cases an order of magnitude higher than those achievable with ordinary CWs. In one type of advanced aerobic EW, the wastewater being treated flows sub-surface (SSF) beneath an aggregate substrate which is aerated mechanically from below. This ecotechnology allows very much higher removals (>95%) of those wastewater contaminants amenable to aerobic treatment (e.g., BOD, ammonia). A large 1.9 ha EW system treating glycol-contaminated water is now operating at Buffalo Niagara International Airport (BNIA) in upper New York State, USA. This system, which is successfully treating glycol-contaminated stormwater runoff and spent glycol from cold weather aircraft deicing activities, involves four very large aerated EW cells and is capable of treating up to 4,620 m³/d of glycol-contaminated water containing up to 4,535 kg/d of BOD (the BOD-equivalent of a city of 50,000 people), even in the coldest weather.