About 250 Kent County residents attended the meeting organized by two associations representing property owners along the Thornapple River. They learned about Gerald R. Ford International Airport's plans to divert and diffuse the chemical in a retention area before it goes into the river.
The airport proposes spending $22 million on a system to pump storm water runoff through cells in a retention area with fungi and bacteria that would feed on the propylene glycol. Airport officials say doing so would significantly reduce the volume of fluid to about 6,000 gallons annually and would divert storm water runoff. The airport used about 80,000 gallons of the organic de-icing fluid last year.
The proposal follows a 2010 order by the Michigan Department of Environmental Quality to stop the runoff of de-icing fluid from the airport into a tributary of the river. The chemical is blamed for filling the creek with a smelly, cream-colored slime.
The problem with runoff into the creek in Kent County's Cascade Township was discovered in the 1990s and millions of dollars have been spent to capture as much of the chemical for recycling as possible.
Airport officials say similar systems have operated successfully at other airports, but critics have said no amount of fluid should be allowed into the river. They also called for greater transparency by airport and state officials.
"This is the first public forum where people could express their concerns," said Nancy Eardley. "There's a real potential lack of honesty here, which leads me to question everything that's being said."
Vinayak Manohar and others said they seek independent monitoring to determine whether the system is reducing fluid levels in the waterways.
Airport facilities director Phil Johnson said the meeting provided a good opportunity to share the airport's plans and for officials to hear residents' concerns. State environmental officials have scheduled another public hearing next week.