Four international plumbing and building codes now require that water reuse systems comply with NSF International’s NSF/ANSI 350: Onsite Residential and Commercial Water Reuse Treatment standard for water reuse systems.
The 2015 International Residential Code (IRC), International Plumbing Code (IPC), Uniform Plumbing Code (UPC) and International Green Construction Code (IgCC) now all require that water reuse systems used for residential toilet and urinal flushing comply with the NSF/ANSI 350 standard. Water reuse systems reduce costs associated with energy and water use by treating water onsite. The standard requires 26 weeks of continuous testing with regularly scheduled sampling throughout, typically three days a week.
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