Using Composting Toilets To Manage Your Waste Off-Grid

Written by Vince Wheeler

Do Composting Toilets Smell And Are They Sanitary?

They don’t smell if you use them properly. The basic problem that will cause smells is mixing urine and feces. By separating the two, the feces will dry out with the use of materials such as sawdust, peat moss, grass, or wood chips. Any carbon source will do the job. Although a little urine is okay to keep things slightly moist, the majority of urine needs to be diverted into a separate holding tank. You also need some sort of ventilation to move stale air out. When your tank is full, you take the compost/feces mixture and you add it to a compost pile outside. If you do all this correctly, the toilet shouldn’t smell any different that dirt. After two years, that compost has completely broken down all the human elements into rich compost.

As to the sanitation issues concerning composting toilets, this isn’t exactly a “clean” issue. In general, yes they are sanitary if handled appropriately. You have to keep in mind, that until the waste has had enough time to allow the anaerobic digestion activity to break down everything using microorganisms, it is still human waste. To be safe, give your compost two years to get everything cleaned up. Once this process takes place, the compost left over is completely sanitary.

DIY Composting Toilets For Off Grid Homes, RVs, Or Camping Trailers

A five gallon bucket is an excellent do-it-yourself composting toilet. Those buckets you can buy at Home Depot, Wal-Mart, or Lowes are excellent buckets for composting toilets. To get started you build a box to hold the bucket. Some more “advanced” designs will place a saw dust bin where a water tank normally goes. You can also build a small box next to the toilet that has a cover over it. Once you’re done with your box, you’ll need to install a toilet seat on it. Make sure the top of the box has hinges so it can be lifted up to allow the bucket to be removed and dumped. When full, the feces and sawdust (or whatever material you use) will need to be dumped into the composting bin as soon as a month, but it could last much longer depending on how many people are using it and how fast it fills up. The best part is, if the system gets messed up some how (ie. the inside of the bucket gets nasty), the buckets can be replaced for $5!

An important consideration is can you actually create “compost” while on the road. The truth is you can’t without a lot of trouble. Most five gallon systems will fill up fast. A couple weeks is probably the most you’ll get before needing to be dumped. Then the material will still need upwards of a year to fully compost into usuable material. 

Because of this, you should make considerations with you design. You will likely only toss the bag into a dumpster since you won’t have a place to compost your material. This means most of the designs that use airflow to start the composting process are a waste of time. Dry your solids using cat litter, sawdust, or other carbin based material. Personally wood pellet cat litter worked awesome. I was stunned. I didn’t even divert the solids and liquids, yet there was no smell other than pine!

If you are stationary with a place to hold your material until it breaks down, then you can truly compost your waste. If done correctly with the proper heat, time, and moisture levels, you will have perfectly sanitary compost for use anywhere. I personally still can’t get over it’s origin, so I’d only use it for trees and non-edible plants. If you don’t have such issues, use it in your garden and grow food with it.

The Reason Composting Toilets Are Useful

Urine and feces are both turned into fertilizer that is useful to add nutrients to plants. I personally wouldn’t use it for plants I plan to eat, but especially in the case of the feces, after it is allowed to breakdown it is perfectly safe to use for food production if you choose to. In fact, some home improvement stores sell it as compost. As for the urine, I would dilute that with water. I’ve heard that number should be 5-6 parts water to 1 part urine. Use this for trees and shrubs.

I plan to buy my property in the desert. Because most desert has very poor quality soil, composting your waste is an excellent way to start to add layers of top soil that will sustain plant life. By using the this compost to grow specific plants, they can be used to burn in you rocket mass heater as a fuel source. Some trees such as weeping willows will grow fast enough that a continuous cycle of trees can be grown ever five to six years. The list of trees you can grow will be subject to the agricultural zone you live in. For me, another tree that will be useful is mesquite.

In additional to the fertilizer aspect, these systems also reduce the cost of living off grid. By not having to spend upwards of $6,000-10,000 to install septic systems, that money can be used to drill wells, build your house, or even install a fully functional solar array with a battery bank. It’s a cheap and easy solution to control and process human waste.

An Outhouse Is A Old Version Of A Composting Toilet Still Being Used

Outhouses were simple solutions to handle human waste. It is an awesome method to control sewage. An outhouse was built by digging a deep hole and placing a shack above it. The waste would drop into the pit and decompose into compost as long as carbon based material was being added to the mix. There was a slight risk of contaminating water supplies if a pit was used too long. Every few years, it was common for these outhouses to be moved around. After a few years, those pits would essentially return to dirt.

Most counties in the United States won’t allow outhouses. With that said, it is still common in places such as the back country of Alaska and other remote homesteads. Because these locations are so spread out, it is unlikely enough waste can enter the water supply. These are safe systems.

Toilet Paper And Composting Toilets

Any material that is carbon based helps the processing of waste within composting toilets, so yes, toilet paper is perfectly okay to use in your toilet. There is no limit to how much you can use either. Use as much as you want. There’s also no limit to the brand or type of toilet paper you can use in your composting toilet. All toilet paper is suitable. It could even help if someone not familiar with your system urinates in it. The paper is typically more dry than peat moss and other carbons being used, so it will help absorb excessive liquid. Wipe away until your heart’s content!

Commercially Bought Composting Toilets

Not up for building your own toilet or would you prefer a toilet that looks more traditional? Then consider buying a commercially designed and manufactured composting toilet. These are the two top companies that produce composting toilets. I’ll include the Amazon link for them. I get the affiliate commission and you get to use free shipping!

1. Nature’s Head: This is a basic unit and cost around $925
2. Sun-Mar (GTG Model): This model is cheaper than most at $600-$800

As with anything in life, there have some advantages and disadvantages to everything. Nature’s Head is the most popular brand on the market. Sun-Mar makes a very expensive model that fits in a house and affordable small systems that fit in RVs.

The NRS ECO-Safe Toilet System

Here is an option that isn’t composting. It provides a small black holding tank that holds just over five gallons of waste. This toilet meets BLM, NPS and USFS for a washable, reusable toilet.

A small compact toilet like this could be a great option for those living in vehicles. Since you can’t truly compost your waste, this option lets you skip the process and dump your tank at a dump station.

The price is very reasonable as well. At the time of writing this article the cost is $239.