ABSTRACT: Graywater is a potential water source for reducing waterdemand. Accordingly, a review was undertaken of graywater reuseregulations and guidelines within the 50 United States. Major issuesconsidered included acceptability for graywater segregation as a separatewastewater stream, allowable graywater storage, onsite treatmentrequirements, and permitted graywater use applications. Existingregulations and plumbing codes in the different states suggest thatthere are impediments to overcome but also potential incentives forgraywater reuse. It is encouraging that regulations in 29 states promotesafe graywater reuse, but there are also inconsistencies betweenplumbing codes and other regulations within and among the 50 states.Impediments to graywater reuse include disallowances of graywatersegregation or collection, and restriction of graywater reuse to mostlysubsurface irrigation with limited indoor use permission. Ease onrestrictions and guidelines to promote development of low-cost andproven treatment technologies are needed to promote graywater reuse.Water Environ. Res., 85, 650 (2013).
KEYWORDS: graywater regulations, onsite graywater treatment,urban residential graywater reuse, storage, permit, impediments,incentives, nonpotable reuse.