Wednesday, November 29, 2023


Is it time to change to a composting toilet?


By Greg Illes

If there’s one single topic that can sponsor an entire evening’s conversation among RVers, it’s the RV toilet. Everyone has their preferences and their funny/horror stories. The horror part is almost always associated with the dumping process, a noxious affair where days or weeks worth of accumulated, concentrated sewage is carefully deposited deep inside some septic system that you have entrusted to absorb the smelly mess.

My wife and I are about to embark on what we expect to be a radical change of life in the toilet department — installing a composting toilet in our rig.

It will no longer connect to the black tank, since it is completely self-contained. We will not be collecting sewage any longer. We will, literally, never have to dump brown stuff again through the “stinky slinky” three-inch drain hose.

For those unaware of the technology, composting toilets have been around for quite a while. They’ve seen extensive use in remote locations, sea-going watercraft, and even in residential applications where folks don’t want the expense of, or can’t get permits for, traditional sewage systems. Some of these toilet units have trickled into the RV realm (no pun intended), and there are many successful installations.

After a huge amount of research on our part (you would be amazed at some of the questions and answers on this topic), we have decided it’s a game-changer.

HERE’S HOW IT WORKS, and please excuse me for getting a little graphic: You use the toilet in standard fashion, and the design of the bowl causes a separation of liquids and solids. This is critical, because keeping the pee separate from poo helps eliminate odors. The poo is mixed with normal garden peat moss in a special agitator bucket, and quickly becomes odorless, benign compost — essentially, dirt. A tiny built-in ventilation fan is all that’s required to keep fresh air over the compost, and any small odors out of the RV.

The pee can be disposed of in the gray tank, in a campground toilet, or sometimes on the ground where permitted (but not in a campground). The compost can be disposed of in either normal trash or on the ground where regulations permit.

There are a lot more details about disposal strategies, but suffice it to say that it’s safe, legal, and simple without using a dump site. Remember, by the time it hits the ground, it’s simply more dirt.

WHAT DOES IT ALL MEAN? Several things. One, we will seldom need a formal dump station any longer. Depending on our surroundings, we will be able to dump gray water and compost soil on the landscape. (In fact, it actually benefits the local vegetation.)

Two, not using water for flushing a toilet will nearly double our endurance on our fresh water supply, extending our boondocking independence for many days. And three, not having any solid wastes in our tanks means we can dump tanks any time we please, and we don’t have to wait for that one-half or three-quarters full to assure proper flow of solids.

Another small advantage is that we can easily do partial dumps and fills, because all we need is a water supply. This will mean that we can carry less water on average, since we aren’t always carrying all the water we started with. Less water is less weight, which will help with the hills and our fuel economy.

Yeah, we’re going to have to get used to actually handling our waste products — but it’s still better than waiting for a sewage-disposal disaster, just above a tank full of everybody’s waste products. A host of experienced users uniformly report no smell or mess issues whatsoever. And for our diligence, we will never have to worry about a sewage leak or backup again, and our flexibility and freedom will be significantly extended. No more searching for a (pricey) dump station, no more lines, no more trip planning around the arrival of the black-tank half-full day.

The composting toilet is more convenient and more eco-friendly than the black-tank standard, and it clearly affords many boondocking and general-travel advantages. But I’m not optimistic that it’s going to show up in factory RVs in any foreseeable future. If you want one, you’ll have to pony up about $1,000 or more and replace your standard toilet with it.

I’ll be smiling a lot as I drive on past the line at the dump station.

Greg Illes is a retired systems engineer who loves thinking up RV upgrades and modifications. When he’s not working on his motorhome, he’s traveling in it. You can follow his blog at



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