Yes, we have to do way better with this problem. Yet the long term solution may well be to integrate effective night soil into all our lifeways once and for all and separate out the grey water system to a different application.
Again this is something readily accomplished in a natural community system were we are managing 150 people and using land as well. Then there is ample use for both the night soils and the grey water. The night soils are immediately useful as an additive to cellulose rich composts to correctly break them down. The grey water carries soap which is a handy fertilizer for the garden.
Otherwise we need to master the fine art of night soil containment and we have generally been lacking there. Water has been added so adding an agitator is obvious in order to liquify it all. This at least makes it all pumpable. We are going this with pig manure to produce a raw sprayable sewage as it is. Thus a compact home based system seems reasonable. Further processing is the real problem although it is now in a form it might be handled.
We may have to wait for robots to make this one work well unfortunately.
Why the modern bathroom is a wasteful, unhealthy design
This was perhaps the greatest, but now undervalued, convenience. Instead of carrying water, suddenly everyone had as much as they could use, all the time, with the turn of a tap. Not surprisingly, according to Abby Rockefeller in Civilization and Sludge, the average water use per person went quickly from three gallons of water per person to 30 and perhaps as much as 100 gallons per person.
Inside our houses, the architects and homeowners of the late 19th century were as confused as the engineers about what to do. People had washstands in their bedrooms, so at first they just stuck sinks and taps into them, and put the toilet into whatever closet in the hall or space under the stairs that they could find, hence the “water closet.” They quickly realised that it didn’t make a lot of sense to run plumbing to every bedroom when it was cheaper to bring it all to one place, and the idea of the bathroom was born. Since the early adopters, then as now, were the rich with a few rooms to spare, they were often lavish, with all the fixtures encased in wood like the commodes they replaced.
What could the bathroom of the future look like?
Shower like the Japanese
The Japanese used to sell their excrement; the rich got more money for theirs because they had better diets and made better quality fertilizer. They farmed more intensively and had fewer farm animals, (as we probably should) and needed a lot of it. In China, the proverb said: “Treasure night soil as if it were gold.” It was valuable stuff then and still is today.