 Yeah, then of course we have the choice between conventional and dry sanitation and I don't want to go into this too much because we deal with this topic in a different lecture and just one word about the torpedo sanitation concept. For a lot of eco houses people build their own dry toilets. What is okay if you are in a rural setting there is enough space and people are capable and willing of operating them. For most of the world population this is not an option. So whenever you plan for ecological sanitation you should consider a system that is operated professionally. So my suggestion is to have these container toilets that are operated with very very little water and that would be empty just like solid waste disposal collection and brought to a treatment site or being worked into the ground as a humus building material but very few people do have space enough to really deal with their excreta on their own land and it's better to have this in a well in professional hands than people emptying their excreta bins to the side of the ground what is not really a good idea.