WAC 246-274-400. Greywater reuse treatment technologies—Tier 3 greywater irrigation systems

(1) This section applies to treatment technologies for Tier 3 greywater irrigation systems. (2) All proprietary greywater treatment products used to treat light greywater shall meet the requirements of NSF/ANSI Standard 350-1, 2011, of the National Sanitation Foundation International (NSF), " Onsite Residential and Commercial Graywater Treatment Systems for Subsurface Discharge ." (3) All proprietary treatment products used to treat dark greywater shall meet the requirements of NSF/ANSI Standard 40, 2009. (4) All proprietary treatment products shall bear the NSF seal of approval indicating that the product meets the requirements of NSF Standard 350-1 or NSF Standard 40 as applicable. (5) Public domain treatment technologies may be used to treat greywater if the department has developed recommended standards and guidance for the technologies.