What happens to the thousands of gallons of used de-icer after it’s put on streets? In most cases its washed into storm drains with melting snow, where it ends up in either water treatment facilities or rivers and other bodies of water. In Portland though, airport officials are feeding it to bacteria to dispose of it.
What?? Yep, you heard me right. Last year, the airport sprayed more than 60,000 gallons of glycol-based de-icing fluids on their planes and runways, too much to dispose of in a way compliant with the limits of its wastewater discharge permit.
So they had to find another way to get rid of it, which is detailed in this article from Boise State Public Radio.