Water is a precious resource out here in the desert, and something the city of El Paso does not supply to my neighborhood. The health department requires a septic tank, which are not only expensive and extremely invasive to the natural environment, they require a lot of water. So I've been using a better option, a composting toilet, for 3 years now.
A composting toilet flushes with any carbon rich material (sawdust, rice husks, coconut fiber, peat moss, etc) instead of water. The toilet contents are added to a compost pit, and over time it all turns back into a very rich, farm-ready soil. As you use the toilet, 5 gallon buckets full of shit, toilet paper, and peat moss start to add up, and I'll need to "work the compost."
In the desert, we don't get a lot of rain. I tried in vain to compost above ground, but the compost required constant watering to stay active. One summer, thieves stole my compost bin, so the next year i started composting in dug-out pits. The pit above was recently started, and is covered in a layer of straw. I move the cover off the pit, and with a shovel I dig into the middle of the pit, and make a good sized hole.. Pushing the innermost compost out to the edges of the pit.
Generally, when I work the compost, I'll add a bucket of food scraps first. Left-overs, moldy cheese, sour milk, produce scraps, bones, bread ... anything i can't eat, my compost will. Then I'll add the buckets from the toilet.
When I add the toilet buckets, usually there will be some toilet paper sticking out. Toilet paper composts really fast, so I just push it under with the shovel, and I never see it again. If the buckets are bad I will add a little more peat moss here. Sometimes the buckets are bad if there's too much urine, or if, god forbid, some unknowing soul packed the bucket down with a rock to make more room. basically, if it's super wet, or just stinky, I add more peat moss.
After emptying the buckets, i give them a solid what-for with a hose. This gets most of the yuck out, and leaves about 3-4 inches of "compost tea" in the bottom of the buckets. This tea is excellent for pouring into the compost pit as well.
Next I grab handfuls of loose straw and i rub the inside of the buckets with it, leaving a small amount of straw at the bottom of the bucket. Scrubbing the bucket with the straw cleans it pretty thoroughly, getting the rest of the yuck out. Leaving the straw in the bottom of the bucket helps keep stuff from sticking to the bottom. I also add several handfulls of straw to the pit at this point as cover material.
Finally, i give the pit a good solid watering with hose.
After three years of composting out here I've collected a good amount of compost. I have three of these pits, each 3x3x3' in size. I fill up 3 a year, let them cook all summer, and then the following winter, as needed, i dig the pits out and move the finished compost to a larger above ground bin. The bin is at half capacity currently. I hope to have it full by the time i build my greenhouse 2 years from now.