The 2017 Water Efficiency and Sanitation Standard (WE•Stand) was the culmination of a 10-year effort to develop codified water-efficiency provisions that would result in a 20% reduction in water use from the minimum code requirements contained in the Uniform Plumbing Code (UPC).
The 2017 WE•Stand has strong provisions in place for alternate water sources applied toward untreated gray water systems for subsurface and subsoil irrigation and mulch basins, as well as rainwater and reclaimed (recycled) water systems. There are also provisions for onsite treated nonpotable water systems using devices listed to NSF 350. NSF 350 includes gray water, residential wastewater and commercial treatment systems.