My mid-week project this week was building a Sawdust composting toilet

The parts required for this project

(all parts from Home Depot unless otherwise noted):

• Plywood (three 3×3 sheets @ $4 each from local Amish)
• Round toilet seat ($6)
• Two sets of door hinges ($2.50)
• Two buckets ($2.50)
• 2×4 scrap approximately 2 feet long
• 1×2 pine approximately 2 feet long

The total cost for the project is about $30.

Tools used

• Circular saw
• Jig saw
• Miter saw
• Kreg Jig : Kreg R3 Jr. Pocket Hole Jig System (this is the newest version of my setup)
• Kreg face clamp : Kreg KHC-PREMIUM Face Clamp

I used about 40 inch and a quarter Kreg screws  from a set like this one : Kreg SK03 Pocket-Hole Screw Kit in 5 Sizes

All that I have left to do is paint the inside, sand and add a handle to  the sawdust portal, install the t&g pine to the front and apply polyurethane to everything.

Use

To use a composting toilet you need filler (sawdust, shavings, peat, etc). We get our sawdust from local sawmills who give it away. 

You use the toilet like a regular toilet. Put down a a couple of inches of filler before first use then after making a deposit add filler to cover things. Once the bucket is 3/4 full we empty the bucket into a composting area that is away from water sources and cover that with straw to full decompose.

Alternatively you can use a trash bag as a liner. Fill the bucket like above with sawdust for odor but when full seal the bag (maybe double bag) and dispose of in the trash.

After we empty the buckets I wash the buckets with water several times and then clean with a bleach mix and allow to air dry.

I put black electrical tape on the handles of the buckets that are used for deposits and only use them for that. 

Links

• Humanure headquarters
• Humanure handbook

commercial alternatives

• Loveable Loo (exspensive)
• The Cabin Can (less expensive and nicer looking)
• Reliance Products Luggable Loo Portable 5 Gallon Toilet
  •  This is the simplest alternative. If you kept another 5 gallon bucket fill sawdust you could use that as filler. 
• Emergency Zone  Honey Bucket Portable Toilet Seat Cover, Fits Standard 5 Gallon Pails
• Reliance Products Hassock Portable Lightweight Self-Contained Toilet
  • We actually have one of these and used it before we had the composting toilet. You need bags that you seal up once filled and can dispose of in the trash.
  • Reliance Products Double Doodie Toilet Waste Bags (6-Pack)
  • Walmart also stocks these for the same price as amazon. Check the camping section.

There are a number of  full composting toilets that I looked at but they were very expensive (north of $1k) and out of my price range. As I have never used them I am not qualified to talk about them.