Safe Antifreeze disposal after de-winterizing

[Varmint]

Most RV blogs proclaim that RV antifreeze is non-toxic, and you can just dump it on the ground when de-winterizing. But many sources say that even the non-toxic, biodegradable RV antifreeze is dangerous to plants and animals and should never be dumped on the ground. But how are you supposed to flush that stuff out of your camper except by running many gallons of water through the lines to flush it, then driving to the nearest dump station with all that water sloshing around in your gray tank? Does anyone do that? How dangerous is it to drive 22 miles with a half-full gray tank to the nearest dump station? I have a 21BHE travel trailer.

[JKellerJr]

Most RV blogs proclaim that RV antifreeze is non-toxic, and you can just dump it on the ground when de-winterizing. But many sources say that even the non-toxic, biodegradable RV antifreeze is dangerous to plants and animals and should never be dumped on the ground. But how are you supposed to flush that stuff out of your camper except by running many gallons of water through the lines to flush it, then driving to the nearest dump station with all that water sloshing around in your gray tank? Does anyone do that? How dangerous is it to drive 22 miles with a half-full gray tank to the nearest dump station? I have a 21BHE travel trailer.

I tend to flush it out at home and let it drain off the driveway into the yard. Never had an issue. But if you don't want to do that, it not an issue traveling with the tanks half full or full.

[IBEW Sparky]

Most RV blogs proclaim that RV antifreeze is non-toxic, and you can just dump it on the ground when de-winterizing. But many sources say that even the non-toxic, biodegradable RV antifreeze is dangerous to plants and animals and should never be dumped on the ground. But how are you supposed to flush that stuff out of your camper except by running many gallons of water through the lines to flush it, then driving to the nearest dump station with all that water sloshing around in your gray tank? Does anyone do that? How dangerous is it to drive 22 miles with a half-full gray tank to the nearest dump station? I have a 21BHE travel trailer.

When you dewinterize put an empty gallon jug at each low point drain, blow air through the system just like when you winterize and capture 95% of the antifreeze in your water lines. Mark those gallon containers as " Drains & Traps Only" and save them for next year. The remaining antifreeze can be rinsed by running less than 5 gallons of clean water through the lines, catch most of it in a pail at each faucet, shower and low point drains and dump it into your toilet at home. Then run as much fresh water through the lines as you want until you're satisfied. And yes you can run with water in your grey tanks, black tanks or fresh tanks. I never leave home without at least a 3/4 full fresh water tank and usually have about 10 gallons of water/chemical I add to my black tank (after it's emptied) to help rinse it better by sloshing around while I travel. If I'm going to a campsite that is water & electric only I can dump the black tank prior to setting up at my site... If I have full hookups then I don't even worry about it and eventually it will get dumped during my visit.

[Scott'n'Wendy]

How dangerous is it to drive 22 miles with a half-full gray tank to the nearest dump station?

It's not dangerous at all. But it's not dangerous to dump non-toxic liquid on the ground either..that's what I do...

[jjbbrewer]

RV anti-freeze is propylene glycol, which is non-toxic and used in all sorts of things including food, cosmetics and pharmaceuticals. I dispose of it similar to how I dispose of dishwater.

Engine anti-freeze is ethylene glycol, which is toxic to anything that has a liver as it gets metabolized into several different acids all of which are bad.

Two important points about ethylene glycol:

1. It's harmless to things that don't have livers, so I was instructed that proper disposal is dumping it down the toilet or sink followed by some water. I didn't believe that when I was told by my county hazardous waste organization, but they assured me that was ok. Still not believing them, I called our local water treatment plant who told me the microbes at their plants eat it right up with no problem. They said I could bring it to them, but they would just do the same thing. YMMV of course, so call your local people.
2. The antidote for ethylene glycol poisoning is using ethanol to competitively inhibit metabolism of ethylene glycol into toxic metabolites. So to be safe, I keep a bottle of Buffalo Trace in my garage and take a prophylactic pull (or 2) before I work on any cooling system components. Again, YMMV. :-)