Our humanure toilet prototype, built in about two hours for $0.

Whether you 're hosting an event and need a few extra porta-potties, in need of a toilet out by your work room or garage, re-doing your camp on the lake and lack a bathroom, or if you're ready to transition from a water-based septic or sewer system, the "humanure" compost toilet is a simple, cheap, ecologically responsible way to deal with human waste.

First, the stats:

Residential toilets account for approximately 30% of indoor residential water use in the United States—equivalent to more than 2.1 trillion gallons of water consumed each year. (EPA)
Over the course of your lifetime, you will likely flush the toilet nearly 140,000 times. (EPA)
Leaking toilets (even the ones you only hear at night) can lose 30 to 500 gallons per day. (American Water Works Foundation)
Many of our toilets have a constant leak — somewhere around 22 gallons per day. This translates into about 8,000 gallons per year of wasted water, water that could be saved. (United States Geological Survey)

Our main resource for constructing a humanure toilet was Joseph Jenkins' site, The Humanure Handbook. In addition to free compost-toilet plans and tons of great information, he's got humanure toilets for sale, books available on the subject, and informational videos about emptying bins, layering materials, and more.

From that site:

Although most of the world's humanure is quickly flushed down a drain, or discarded into the environment as a pollutant, it could instead be converted, through composting, into lush vegetative growth, and used to feed humanity. The humanure process involves a compost toilet, a compost bin and cover material. Toilet instructions are simple. There are a variety of ways to make a humanure toilet (or you can buy one).

Here are a few images of completed humanure toilets.

There's not a whole lot to the design: You've got a 5-gallon bucket in a wooden box with hinged top, connected to a toilet seat. Next to the toilet, you keep a container filled with sawdust. After each use, a scoop of sawdust is added to help with decomposition and neutralize any odors. When the toilet is full, you empty it into a compost heap outside, add a thick layer of hay or straw (or weeds, dead leaves, or grass clippings), and wash the bin out. How gross is that? Not as bad as you might guess: Click here for full instructions (and video) on emptying and cleaning receptacles.

The purposes for composting humanure include preventing water pollution, recycling human excrement to prevent fecal contamination of the environment, and recovering soil nutrients for the purpose of growing food. It is recommended that you keep a two- or even three-sectioned composting system so that you can let your compost decompose for up to a year before it is broken down completely for use in a flower or vegetable garden. The compost system can be used for all compostable home items (from grass clippings to veggie scraps to humanure).

For our humanure toilet, we used a 5-gallon bucket, plywood scraps we found in the wood shed, an old toilet seat cover, and a few screws. We used the directions available for free at Jenkins' website (click here for those plans). Here's Greg making the fit for the top of the box: