Airport completes $20 million project required by DEQ
Goal is to mitigate stormwater runoff residue in Thornapple River and nearby creek.
Gerald R. Ford International Airport has completed a $20 million water treatment system required by the Department of Environmental Quality.
The system, which deals with runoff from stormwater and winter deicing activity, is the first of its kind in Michigan.
It was required by the DEQ as part its issuance in 2013 of a National Pollutant Discharge Elimination System permit to the airport.
By issuing the permit, the DEQ required GFIA to address the seasonal issue of biofilm accumulation in the tributary known as Trout Creek, which had led to increased citizen complaints. The tributary leads into the Thornapple River.
Residents living along Trout Creek have reported the formation of a biofilm on the river, which is a result of the propylene glycol from the deicing fluid used at the airport. They said the biofilm emits an unpleasant odor each spring and may be to blame for the deaths of fish and other wildlife in and around the tributary.
The new stormwater and glycol treatment system project involved re-routing stormwater from the airport’s north detention basin to a new outfall at the Thornapple River, and reconfiguring the airport’s west apron stormwater system to consolidate runoff from all major existing and future aircraft deicing areas.
The stormwater treatment system includes a green design that uses gravity, vegetated beds and natural organisms to treat the stormwater with essentially no power consumption or residual waste.
Brian Ryks, executive director at GFIA, said the natural treatment system is the “centerpiece of our new stormwater management program” and will strengthen the airport’s environmental performance.
GFIA’s stormwater management will ensure the stormwater reaching the Thornapple River will be well within Michigan’s water quality protection standards, and will provide significant improvement to the river.
“Although neither of these problems has ever been reported in the Thornapple River, nuisance levels of attached bacterial and algal biofilms have presented a problem in an unnamed tributary (Trout Creek) that currently carries stormwater from GFIA to the Thornapple River,” the airport said in a press release.
Erv Gambee, president of the Thornapple River Watershed Council and a member of the project’s stakeholder committee, said he is happy with the final treatment system.
“I look forward to seeing positive test results at the confluence of the discard and the Thornapple as well as the restoration of Trout Creek as time moves on,” Gambee said.
With the treatment system completed, additional pollutant sampling for two discharge events will be conducted.
The Federal Aviation Administration requires aircraft and pavement deicing during cold weather months.
The airlines at GFIA use propylene glycol, an organic compound commonly used as a food additive and in personal hygiene products.
Some of the applied deicing material is carried into the environment by stormwater, including snowmelt, rain and other precipitation, which flows to area waterways.
The Clean Water Act requires airports to obtain permits to fully protect the environment from any risks propylene glycol might present.
The airport said propylene glycol is highly biodegradable, which means it “does not linger in the environment,” but it does present challenges for waterways.
The first challenge is that propylene glycol’s fast biodegradation competes with some organisms for dissolved oxygen in the water, and second, it provides a rich food source for naturally occurring algae, fungi and other aquatic organisms, allowing them to proliferate to nuisance levels under ideal conditions.
In addition to the new treatment system, GFIA said the airport has “implemented progressively more sophisticated conservation, collection and recycling activities” to minimize the amount of applied deicing fluids in the airport’s stormwater runoff.
The new treatment system has earned an Airports Council International, North America Environmental Achievement Award for Outreach, Education and Community Involvement.