Airplane deicing is at the center of a debate regarding storm water runoff pollution at Gerald R. Ford International Airport. ©iStockphoto.com
Plans for construction of a new $20 million water treatment system at the Gerald R. Ford International Airport will move forward thanks to approval from the Michigan Department of Environmental Quality.
The DEQ announced that it has issued the airport a first-of-its-kind discharge permit. The National Pollutant Discharge Elimination System permit issued by the DEQ addresses the seasonal issue of biofilm accumulation in the tributary known as Trout Creek.
Plans for the new water treatment system were developed over the course of the past year to remedy water runoff issues caused by the airport’s annual use of deicing fluids.
Currently, airport runoff is discharged from a detention basin located in the northeast corner of the airport into Trout Creek. Each year residents living along Trout Creek have noticed the formation of a biofilm on the river, which is a result of the propylene glycol from the deicing fluid.
According to area residents, the glycol runoff has resulted in the deaths of fish and other creek wildlife as well as emitting an unpleasant odor each spring as it dies off.
As a result of resident concerns, the DEQ directed the airport to eliminate its contribution of glycol to Trout Creek by Oct. 1, 2015, in order to receive its next storm water discharge permit.
Area residents and local officials have shared their concerns about the problem during public meetings this year and through an extended public comment period. A permit condition was developed in response that requires the airport to report on the effectiveness of the new treatment system. The permit further requires additional pollutant sampling for two discharge events after the treatment system is operational.
With the DEQ approval the airport will begin construction on the treatment system this fall and the project will be completed by the fall of 2015.
The new treatment system will reroute the runoff directly into the Thornapple River and includes a natural treatment system that consists of treatment cells that the runoff travels through before reaching the river. The vertical system includes a top layer of dry vegetation, followed by two layers of sand, and then by two layers of gravel.
“The proposed basin will act as a sediment trap and also act as a trash removal facility,” Thomas Ecklund, facilities management director for the airport, previously told the Business Journal. “The flow will leave the basin, and the basin is designed to control the flow into the first set of cells. The flow will go through the first set of cells and receive treatment. It will then be discharged into the second set of cells where that treatment process will be duplicated. It will then go into a third stage of treatment, which is basically a riprap channel to add some oxygen into the flow, which is important to improve quality.”
Ecklund said the bacteria that feed on glycol would use the material as a food source during this process.
The airport will continue its collection and recycling program, which it said successfully collects 28 percent of the deicing fluid. Another 36 percent is not collectable as it stays on the aircraft, evaporates or biodegrades.
This will be the first on-site treatment system for de-icing fluids at a Michigan airport. Regulators expect it will improve water quality in the Thornapple River and Plaster Creek watersheds.
Many residents are still concerned, believing the treatment system will simply deflect the glycol and biofilm issue to the larger Thornapple River, creating the same problems there. Many residents have expressed that they would like to see the airport eliminate its glycol discharge to the Thornapple altogether.
However, Ford Airport Executive Director Brian Ryks and Ecklund have remained adamant throughout the past year that the treatment system will be an improvement and that runoff into the Thornapple River will not harm the river.
“For the last 10 to 13 years we’ve had an average of about 36 percent going into the Thornapple,” Ecklund said. “When this project is completed, that is going to be reduced down to 7 percent.”
Ryks noted that the 7 percent is mixed with 325 million gallons of storm water.
“It will significantly improve the quality of the water in the Thornapple from what it currently is today,” Ryks said. “We feel very good about it … It’s proven technology that has been instituted at a number of other airports.”
The DEQ said a web page would soon be available with regularly updated information for concerned residents and interested groups.