What other
water treatment technologies would work? I have a feeling turning brown water into drinking water would not be 'palatable' to most people.
This article talks about a few of the newer technologies available.
https://www.amtaorg.com/Water_Desali...Processes.html
This is the Carlsbad CA plant webpage. Lots of info about how it works, not so much about waste products. Not sure if there is anywhere in the world more concerned about the environment than the Country of California - my guess would be that they have mitigated most of the environmental concerns either with this state of the art technology or through other means.
http://carlsbaddesal.com/