Tools & Materials: All that you will need to build a waste composter is a shovel, a saw, a drill, 4" pvc pipe, and a vessel of some sort.
First find your vessel. I decided to use a salvaged plastic 55-gallon barrel and give it a third life. A 5-gallon bucket or a trash can would work if you have a small dog. Rather than recycling the barrel I simply reused it. I got it from our local coffee roaster and used it as a leaf composter for a couple years. Be careful that you don't use a barrel that may have had toxic chemicals in it. Mine used to be full of French vanilla flavoring. That stuff is fairly harmless.
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Step 1: Preparing the Vessel
If you are using a barrel you will need to cut the top off. The open end will become the bottom of the compster. This will increase the surface area that is exposed to the soil and allow rain water to drain easily.
Next cut a circular hole into what will be the top of your composter. I cut a 4-inch hole into mine because I decided to use a 4-inch inside diameter (ID) pvc pipe as the access port for my composter. It's good to have a hole large enough to allow the dog waste to fall into the vessel without the need of a push-stick. The 4-inch ID pvc fits perfectly over the 4-inch hole without the danger of falling in. I was able to find a waste cut piece of pipe that was headed for the dumpster.