Plumbing systems...
The water supply is obtained by collecting rain from the roof. The original design called for 2 - 5,000 gallon cisterns (one on each end of the house).
We have operated for 10 years with only one cistern finished and functional without problem - so we figure one cistern is probably enough given the large amount of rainfall we receive in this part of the country. Our intention is to knock a door through the wall of the other cistern and turn it into a root cellar.
The water is pumped from the cistern to a pressure tank. All this is relatively conventional. The variations come in the gray-water recycling through the wetlands, as well as the use of a composting toilet. We did stub out for an eventual exterior "black water" treatment system that we will likely convert to some time in the future.
The shower room is separated from the toilet area (European style). The walls of the shower are made of cans and bottles, coated in concrete, and then tiled.