Can this really be done? If you only run the toilets and kitchen sink to it. (think black water. We know what to do with grey water.) Could a composting toilet system keep up with a “normal household” load? These are a few of the questions I would like answers to.

Let’s try to answer the first question; Can this really be done? Not in my current neighborhood. But if I were to live in a more rural setting then, yes it could easily be done. The most major consideration is that the main unit be located below everything else. If one was thinking about a large slab foundation, this would be a problem. One would almost certainly have to have a basement.

Question number two; could a composting toilet system keep up with a “normal household” load. We will take normal to mean a household with 4 people. The real question becomes; how much water enters the system per day. For kitchen use we will say twenty gallons. For toilet use, we will say 55 gallons. That equals about 30 toilet flushes with a regular toilet. Low-flush or composting specific toilets would be less. For now, I will just use this number. From the information that I been reading, no. The system would have to evaporate almost 80 gallons of water a day. That is just too much.That said all the central systems have an over flow outlet. This could work but I believe you would always be overflowing.

If you used the SeaLand Toilet, you would reduce the 55 gallons down to a little under 2 gallon. That is because the SeaLand only uses one pint of water to flush the toilet. I think a the system could handle 22 gallons. But if we were to remove the kitchen waste water it would work as intended. The problem is that the kitchen waste water can have a large amount of food debris. This would not be a good idea to introduce into a gray water system. It could be done, but you would have to drain the sludge out much more frequently.

Third question; What about local building codes? If I was an inspector I would like this system better than a septic system. You are not burying anything in the ground! I am sure many people have had no problem with the inspector.

Lastly, cost. Does this thing cost more? No, in many cases it should cost much less than a septic and leach field. How much? I don’t know. But the top of the line unit sells for a little over $2000. + $500 per SeaLand Toilet  Having priced septic tanks for my rain water collection investigation, a 1000 gallon tank costs $1000. Then you have to deliver it. Then you have to dig a big hole for it. All that and you still need a leach field. Ever had to have your septic system repaired$$$.

Yes, if I were to build a home away from a local sewer system I would have a composting central toilet system and a gray water system. I would not want to bother with a septic tank or a leach field.