Composting Toilets USA

Modern composting toilets offer an environmentally friendly and odor-free method of dealing with human waste. There are many models available at different prices, each with advantages and disadvantages.

Thinktank Composting Toilet

Thinktank Composting Toilet

My first experience with composting toilets goes back about 20 years. After delaying it as long as possible, I had to make a trip to the dreaded outhouse in a Washington State park. However, I immediately noticed there was absolutely no odor. This was unlike every other “outhouse” I had used – where the smell is usually unbearable. A small plaque announced it was a composting toilet – producing natural fertilizer rather than toxic sewage. “Why didn’t someone think of this before?”, I asked myself.Separett composting toilet power free installation

It turns out they had.

In Europe, composting toilets have been around for generations. These toilets are often called “waterless toilets”, and they are installed in homes, offices and government buildings – wherever a toilet is needed. Contrary to a popular misconception, there is no unpleasant smell if a composting toilet is installed properly. North Americans have been much slower to adopt composting toilet technology. However, fresh water is becoming a scarce resource in many areas. It seems wasteful to flush away gallons of pure drinking water every time we use a toilet. In 2005, Americans flushed away 123 billion gallons of water, according to a U.S. Geological Survey report.

Conventional sewage treatment is sometimes impractical or too expensive. Septic systems have many potential problems, not the least of which is disposal of the contents in an environmentally sound manner.

How do composting toilets work?

A true composting toilet produces a safe, non-toxic final product that can be placed on ornamental plants. No expensive or energy intensive treatment is required, and no toxic sludge is produced. Best of all, once the composting toilet is installed, it costs almost nothing to operate.

Separett Composting Toilet urine drain pit.

In a “urine separating composting toilet”, the liquid can be diverted to a small gravel pit (or “French drain), where it percolates safely away

In a “urine separating” composting toilet, the liquid can be diverted to a gray water system or a small gravel pit (sometimes called a “French drain), where it percolates safely away. Urine is virtually sterile, and does not pose a health risk.

The exact process varies depending on the composting toilet. Generally you have a traditional looking toilet seat and bowl, which sits above a storage tank. This tank may be built-in as part of the composting toilet, or it could be installed below the bathroom in a basement or crawlspace.

Some of the newer composting toilets separate urine from solids.

This is a big step forward. The relative lack of fluids in the storage tank helps eliminate odor. Complete and rapid composting occurs easily. Further dehydration over time allows the solid material to shrink dramatically (just like a compost pile). A small self-contained composting toilet can hold a surprising number of “uses”, meaning you do not have to empty it frequently. Excellent examples of urine separating toilets are the Thinktank Composting Toilet and Separett.

Most of the older composting toilet designs hold the urine and solids in one tank. Water evaporates with the aid of electric heat, with the same odor free results – at least theoretically. In practice, you must be very, very careful not to introduce more liquid than the unit can evaporate. Peat moss, coconut fiber, biological compost starter or other organic material is often added to the composting toilet to initiate and aid the composting process. In some toilets the solids are rotated, to speed up composting. With some simple home-made composting toilets you just cover fresh material with a layer of sawdust. This requires a LOT of sawdust, generally 1:1 with human waste, meaning you are adding and removing material much more frequently than with modern urine separating designs. It also means you have to store sawdust inside the home – not a great solution.

Ventilation of the composting toilets is extremely important.

Commercially available composting toilets use fans to dry out the contents and prevent odor. These fans are usually very quiet – 30 db to 40 db. (Which is between a whisper and a refrigerator in volume). They usually run all the time, 24/7. The fans pull air from the bathroom area, through the composting  toilet and out a pipe to the outside. You never smell anything, even when sitting on the open composting toilet. This is because the fan is pulling air away from you. The fan will exhaust any odor outside, and it cannot waft up into the room.

Composting the solid waste – humanure.

When the solids bin fills up – and this can take between a few weeks and years depending on the type of composting toilet and how many people use it – you empty the already well-composted material into a suitable bin or container so it can “mature”. There should be little or no odor at this stage, other than a slight “earthy” smell. You can read a more detailed article on how to compost human waste here.

Thinktank Waterless Toilet

Thinktank Waterless Toilet

How long it must sit is a matter of some debate. It depends on the temperature. Below about 12 degrees Celsius or 55 degrees Fahrenheit composting will slow or stop. Some experts believe letting the compost sit for 12 weeks at room temperature should render pathogens harmless. Others recommend a more cautious 6 months, or even 1 year or longer. It is then safe to use the finished compost on flowers or other non-edible plants.

Can it be thrown in the trash?

If absolutely necessary, and as a last resort, you can bag and seal the solid waste from a composting toilet in a heavy duty plastic bag and dispose of it elsewhere. Many people ask if it is legal to put it in the garbage, and there is no clear answer on this. While this is not illegal anywhere I personally know of, it is not expressly permitted either. Throwing human waste in the trash is a bit of a gray area. However, I don’t see it as much different from throwing out disposable diapers. I suggest double bagging it in strong plastic bags if you must go this route.

Composting toilets require almost no maintenance and are impossible to plug.

Composting toilets are hygienic, inexpensive in the long run and environmentally benign. As fresh water becomes ever more scarce we are sure to see wide spread acceptance of this technology.

The above discussion attempts to answer the common question: how do composting toilets work? Please also see the pages on how to safely compost human waste, Separett Waterless Toilets, and Thinktank Composting Toilets.

Note: Canadian visitors can get important information here: compostingtoiletscanada.

Composting Toilets USA is a division of GreenLatrine Composting Toilets Ltd.
US mailing address:

Unit 79A
446 Harrison St
Sumas, WA 98295

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Composting Toilets
Average rating:  
 23 reviews
 by Joanne Siebert
Pleased with the Thinktank

We have had 3 composting toilets and the Thinktank is the best so far. It is built to last. Customer service is great.

 by Annamarie Longfellow
Pleased with toilet & excellent service.

We converted a shed into a tiny home and added space for a shower and toilet. I am grateful the toilet we were looking at was no longer available from another source. Customer service is amazing - answered all questions from contractor and myself. We chose the Thinktank. We created a drain for urine. My son BOMBED a few weeks ago and there is no smell. The fans are quiet. Thankful we needed a much smaller container to refill for shower as toilet needs no water.

 by Damia

Richard was available when I called. He redirected me from purchasing the wrong toilet for my tiny RV bathroom. When the shifter handle malfunctioned on my Nature’s Head, he sent me a spider handle replacement free of charge.
His customer service is remarkable!

 by Dave
Game Changer

I’ve had my Natures Head composting toilet a little over 3 years. It has been nothing but incredible. I have a cabin that I’m in 5 months a year everyday. The toilet is so easy and maintenance free. Absolutely NO ODOR!!! All my family and friends are amazed that it is really odor free. I will be putting one in my RV in the near future for sure. Out with the pain in the butt Cassette toilet.
5+ Stars for sure.

 by Nancy
Is it appropriate to love a toilet?

Well, appropriate or not, I really do love this toilet.

I am so excited to have a Nature’s Head composting toilet in my barn studio! It was delivered a couple of weeks ago, and we installed it last week. It’s very easy to use and everyone that’s been over to the studio is fascinated by how it works. But even better, no more trips back to the house in knee deep snow to use the facilities. What a treat!

The toilet is clean and compact, easy to install, and my husband built it into a tidy little enclosure complete with a door sporting a half moon. Very stylish :).

I am also most appreciative of the helpful support from Richard as the toilet was back ordered for a while due to supply chain problems (Covid). He was great about responding to questions about delivery dates and reassuring about shipping.

If you are looking to buy one of these water saving, small space toilets, this is definitely the company to come to. They are great!

Thank you!
Nancy Richard

 by Tom
Great experience

I’ve bought two Nature’s Head toilets. They work well. The customer service is superb.

 by Janet Acker
Love our Separett

The entire purchase from contact Richard with questions to installation and now 5 months of use has been flawless. We could not be happier with our Separett.

Thank you Richard!

Great service

We had already purchased a Nature's Head from the main company and called with questions. Their customer service was friendly but not the help we needed. Richard had all of the right answers and was genuinely helpful. We will be installing a second Nature's Head and will definitely take advantage of his Super Pac deal. Being able to count on his support as we install these in new construction makes us really happy!!

 by Meaghan Swift
Did the job

It's hard to get excited about a toilet - what can I say? It works. It doesn't stink. The customer service is exceptional.

 by Lori B
I was prepared to hate this thing, but I love it.

This is easy, clean and odor free. Richard spent a long time with me on the phone and made sure it was right for me. No sales job!

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35 thoughts on “Composting Toilets by Composting Toilets USA

  • Annamarie Longfellow

    We haven’t received our toilet yet but I wanted to comment on customer service. My contractor researched site and discussed purchase with me. He made a call to ask questions and was directed to the new Thinktank waterless toilet. My contractor and I discussed this new toilet and I thought it sounded much better. I called to place order and all my questions were answered. I was steered away from making an extra purchase and he explained why I didn’t need to spend extra money. I feel very confident that we will have further excellent service should any issue arise. We’ll post a photo after installation. Both times we called, we left a message. Our calls were returned within a few minutes. After so much hoopla with trying to get service these days, this was an unexpected pleasure. Like the good old days.

  • LuAnne Potts

    I am extremely satisfied with my Separett toilet. Richard was most helpful in my choice of toilets. I have been using it for about 4 months and it works perfectly. My husband and I have a fishing cabin and thought we were going to have to put in a regular toilet and do a lot of work to get a septic tank put in. When I was told to check out composting toilets I was skeptical at first but after ordering and installing the Separett, it was the best decision we could have made. My sister is putting up a she shed on her property and is going to order one because I like mine so much. Thanks for all your help Richard.

  • Dyani Walden

    Hi , I’m in the process of buying land that is fairly remote and off the grid, I will have excess to electricity but want to use solar power as much as possible. I’m looking for the best composting toilet for 2 people on the weekends, with easy install and that doesn’t draw a lot of power. Thanks

  • Shana Blagrave

    We are thinking about putting a compost toilet in a new house we’re building for my mother in order to save us from having to install a septic system…is this a good idea and if so which toilet would you recommend? I look forward to your thoughts on this.

    • richardbrunt Post author

      Yes it may be a good idea, but this is a huge topic that cannot be quickly addressed. There are many variables. Please read the site carefully, then call e with specific questions.

  • sandra lane

    We have property we are fixing to build a home on. The property will not perk so they say we need a high dollar special septic system. Been looking into composing toilets instead. What info could I look more into. On saving the money on not going with special system an going with composting.

    • richardbrunt Post author

      There are two toilets on my site that could work for you. Please read about them, and read the entire site to get an education on composting toilets. Call me afterwards.

  • anthony

    On these toilets in a rv will it create outside odor? And how would these compare to a waterless toilet connected to a black water tank? Well price wise

    • richardbrunt Post author

      No odor if you vent through the roof. There may be slight odor near the vent if you vent through a wall. I don’t know the answer to the second part of your question.

    • Patty Frantz

      We have a SunMar compact in our cabin. I have followed directions and it stinks like urine. We will use outhouse for other functions until we get the composting procedure down. I’m out of patience with ours. The fan is noisy. Even outside cabin. I’m frustrated and would like to find something quiet and not smelly!

      • Jensen

        I have a SunMar as well I am so frustrated with this composting toilet. The smell and the drainage is the worst! The bugs as you can tell I could go on. In the meantime it’s either get rid of it, re design? Hugh costly mistake

      • Diann

        I had a large sun mar and used peat moss or coconut coir with every use. No odors with up to 10 people visiting on at least 2 weekends per month. My unit was the largest model available. I am glad I don’t have that many weekend visitors any more and am looking forward to my own personal natures head. My neighbors have one and rate it THE BEST!!

  • Susan

    I am having to ship a composting toilet over to Hawaii, and Richard has been SO helpful getting my questions answered and helping facilitate a speedy shipment. It’s costing more to get it there quickly (it IS going to an island in the middle of the Pacific, so…) but I am sure it will be worth it and solve some problems over there for us. I will let everyone know how the toilet works out for us, and if it is as great as it sounds, I will be ordering another one…but this time with a little advance notice so it can travel by boat! Thanks, Richard, for all the assistance and for running your biz “old school”. It’s such a rare thing to connect with the actual person running the business…even on a Sunday!!! That fact alone was enough to make me choose to do business with you! Mahalo!

  • BJ in Denver

    In our travel trailer, I would like to replace our regular “RV” toilet with a composting one. I have a few concerns, though.

    1) how do I vent it, and how do I power the vent?
    2) Can it sit idle, and freeze, for months at a time? Do you have to do anything special when you start using it again?
    3) We have a “wet” toilet/shower. Is it waterproof?
    4)Can we mount it to the floor AND block the blackwater drain at the same time?

    • richardbrunt Post author

      1) You vent it outside, through the roof (usually) or possibly through the wall or floor. You can call me to discuss. You power the vent with 12 volt electricity from your travel trailer, or use a solar vent.
      2) Yes it can sit idle and freeze. No problem. Empty the urine bottle. Nothing needs to be done when you start using it again.
      3) It is not waterproof. You need to protect the fan housing with a plastic bag when showering. Many people do this with no difficulty, as the shower in many smaller RVs and boats is shared with a toilet.
      4) Not sure what you mean here. You will no longer need the black water drain in your bathroom area. What you do with it, I cannot say.

    • Julie Berry

      We have a Nature’s Head in our RV. It is only a little taller than a regular RV toilet. We had it installed, but I could do it myself next time. We full time (2 people) in our RV and the bin needs to be emptied about once per month.
      1) Our vent is a plastic hose that goes into the floor of the RV and connects to a tube that goes through the basement and outside. The end of the tube is covered with screening to ensure that dirt daubers don’t build a nest in the vent. If you put your hand under the vent, you can feel the air from the fan, but we never have any odor.
      2) We haven’t left it idle for long periods of time.
      3) If the toilet is closed up, the fan should be protected from the water as it is mounted inside the toilet and has a non-vented hose from that to your outside vent.
      4) Ours is mounted where the old RV toilet was and the black tank is plugged (you can see the plug when you remove the toilet for cleaning). We had the blackwater tank sanitized and then mounted a leveling tube between the black and grey water tanks for when we’re boondocking and need extra grey water storage. This somewhat works, but not great. Our holding tanks are not accessible or I would just remove the tank. As it is, if we ever sold it and the new owners wanted to revert to a regular RV toilet, they just remove the tube and they’re all set.

      The Nature’s Head has served us well (almost two years now) and now I’m looking at composting toilets for when we have our next home.

  • Katherine Templer

    Fan. Fresh air exchange . With removal of contaminated air does this create a vacuum inside the air tight tiny house removing the heat and AC. Is the vent designed to push and pull fresh air?

  • Eloise Kemner

    Really learned a lot from your composting toilet question and answer video. Two things I wanted to know. If your 1 and 2 deposits
    go in at the same time…How and/or does it separate liquid from solid. Second question is how do you clean your composting toilet inside and out & with what? What do you use? Is it just water…or water and vinegar maybe or what. Thanks so much

    • richardbrunt Post author

      It’s pretty low tech. The front of the bowl is a big funnel, and the back is a big chute. When both men and women sit on the toilet, #1 generally goes forward and #2 goes back. That’s all there is to it. They can go in at the same time. You clean it with water, or water and vinegar. If the outside needs a major clean you can use a soft cloth and a NON ABRASIVE cleaner like soft crub, or a gel coat cleaner designed for acrylic shower stalls.

    • richardbrunt Post author

      With the Nature’s Head the urine is collected into a bottle, and you dump that into a toilet, holding tank, gray water system, or drain pit. The Separett drains directly into a gray water system or drain pit. The Nature’s Head can also be plumbed to drain directly into a pit, with some creativity.

    • Julie Berry

      Emptying liquids is pretty easy. The “jug” has a lid and you carry it from your bathroom to outside. If we are in a campground, we empty it into the septic system. If we are boondocking, we “spread” it around bushes and on the ground. It’s about two gallons so we don’t put it all in one spot but, basically, it would be like “going behind a tree” when you’re tent camping or hiking.