well it's about time :-) but I do point out that waterless toilets can be done with extremely simple low technology -- sawdust and redworms and time -- and then you don't need the electricity to power the vacuum pump, or to mine the magnesium to add for the chemical processing, or all the fancy plumbing and tankage, or indeed much of anything except some old biomass, worms, a suitable bucket, a comfy seat, and a worm box/compost pile.  and a few minutes fof labour per person once a week to empty the buckets (separate for pee and poop).

for a condo, hotel, dorm, apaatamentu or similar concentrated dwelling form, the more complex centralised power-dependent system is probably justifiable as the energy it consumes is more than offset by the energy savings of the multifamily unit (big win in heating and water delivery and so on).

of course Chinese villages have been using biogas digesters for years and years and years to generate cooking fuel.

affluent western notions of human waste management are right up there with SUVs as primary indicators of social psychosis imho <grin>  1) throw away a valuable resource, deliberately interrupting the nutrient cycle and starving the soil;  2) waste a lot of potable water; 3) introduce a lot of artificial toxins ih processing to "neutralise harmful products" in the blackwater before 4) dumping the hypernutrified water into local rivers, streams, near-shore ocean areas where it causes all kinds of havoc and mischief from excessive nitrogen concentration plus the chemical processing cocktail... and of course 5) the icing on the cake is a random melange of half-digested medications, toxic cleaning and cosmetic products, etc.

and yet our culture thinks that the flush toilet is an emblem of advanced civilisation -- when it oughta be an emblem of colossal cluelessness, right up there with the other moai of our times.

I'll bring some more links to this party when I have a mo to riffle through the files.  good topic Nomad.

[btw don't you owe me a diary or a post on noise from wind farms?]

The difference between theory and practise in practise ...