Its zero waste because it puts the waste water into your hotwater supply.
http://www.premierh2o.com/watts/show...ID=121&CATID=1
Opps, just noticed you already said how its gets zero waste.. really big deal.. you don't have to drain it as it is.. you can use it for washing or whatever. They just make more convenient for you. But it looks to be that it is just a pump and a solinoid. Probably by the parts cheaper on Ebay and make it yourself.