I'm probably going to get some grief from this, but I believe Ethylene Glycol when diluted with sufficient water
is not toxic and actually breaks down pretty quickly into I believe carbon dioxide and water maybe?
I know when I was working for Uncle Sam, there were many things we had to be very careful to not discharge, but I don't think anti-freeze was one of them.
Assuming you collect it all up and don't spill a drop of it, what do you do with it?
I'm sure in California
it's probably re-cycled, but I haven't seen it myself?