Extreme Water Recycling: The Future of Cities?
San Francisco is leading the way in the trend of extreme decentralization of water and wastewater, with on-site recycling systems being installed in new commercial and residential buildings as well as districts. The systems will make water for nonpotable use cheaper than buying potable water from a centralized source, driving down demand for potable water and helping manage water more efficiently. The technology for buildings to capture and treat all their water to potable standards already exists, but the safety of direct reuse of recycled wastewater is still being studied, and U.S. regulations so far do not allow that. A fully circular system, in which water is reused on-site for both potable and nonpotable uses, is at least five to 10 years away in this country, experts say.