I like the idea of capturing the methane for use as a fuel, but how does one add additional material to the tank without releasing methane into the room? You know, you lift the lid to take care of business and release a couple of cubic feet of methane that you have to breathe while taking care of business, then you have to wait a few hours before the pressure builds enough in the tank to start supplying methane to your cook stove again, etc.
So where do we pee, if not in the methane tank? In the sink? Is urine completely free of potentially harmful micro-organisms? Or does it need time to cure? I know it is rich in nitrogen (from the ammonia) but this will outgas quickly if not fed to the soil soon? Also, nitrogen is a vital ingredient in compost bins. The bacteria there need it to live and decompose material high in cellulose so why do the bacteria in the methane tank not want nitrogen/urine?
How can we be sure that our gray water is clean and clear of microbes and/or harmful chemicals? I know the easy answer, just don't put anything in the drain that is bad for the plants, right? But is there a way to pre-filter the gray water before feeding it to the plants? Have you considered this? Is it necessary? Also, will the anaerobic decomposition of human manure destroy parasites and/or microbes? Do we need to plan on further sterilization of the finished product before using it as fertilizer?
Offered by Roger.