I installed a composting toilet a few months ago at an off-grid cabin in the mountains. The important thing to get right is the venting system. This keeps a n

I installed a composting toilet a few months ago at an off-grid cabin in the mountains. The important thing to get right is the venting system. This keeps a negative pressure in the compost chamber so air is continually drawn down through the toilet and up out the vent stack. When this is working correctly the bathroom will have no smell at all. The second thing to worry about is the overflow drain. Depending on temperature and usage, urine may not evaporate faster then it is added. There is an overflow drain to handle this situation. Local building codes may require you to pipe the overflow to a conventional septic system, thus negating a lot of the cost and simplicity benefits of a composting toilet.