A google search for "antifreeze disposal Illinois" turned up 28,100 options. I didn't read them all but I found none that condone putting chemicals in drains or dumping it on the ground. I did find several recyclers in the Chicago area that service commercial customers. It shouldn't be difficult to find one that would take small batches from individuals. I also found that the state EPA sponsors cleanup with hazardous waste disposal. Cities need to apply for it. If Sandwich doesn't participate maybe you should go to a city council meeting and ask why.
I did find that there is no US EPA regulations for the disposal. But that fact shouldn't prompt any social minded person to just dump it.