Summary of Oregon's Water Reuse Guideline or Regulation for Onsite Non-potable Water Reuse
This page is part of the EPA’s REUSExplorer tool, which summarizes the different state level regulations or guidelines for water reuse for a variety of sources and end-uses.
The source water for this summary is Onsite Collected Waters.
On this page:
- Technical basis
- Background on NSF/ANSI Standard 350
- Types of onsite non-potable reuse approved for use in Oregon
- Water reuse category/type
- Onsite non-potable reuse specifications (table)
- Upcoming state law or policy
- References
- Disclaimer
This page is a summary of the state’s water reuse law or policy and is provided for informational purposes only. Please always refer to the state for the most accurate and updated information.
In Oregon, onsite non-potable water reuse The use of treated onsite collected waters for non-potable purposes at the single-building or district scale. This reuse application excludes the use of recycled water from a centralized treatment and distribution system for landscape irrigation or commercial uses. include irrigation, wash water and fire suppression systems, among others. The source of water onsite collected waters Water sources generated within or surrounding a building, residence, or district. Other terms referring to this source of water include onsite collected stormwater or rainwater, greywater, blackwater, air conditioning condensate, and foundation water. is specified by the state as graywater. The write-up uses state terms when discussing sources or uses of water that may differ from the Regulations and End-Use Specifications Explorer's (REUSExplorer's) terms.
Technical basis
Oregon approves the onsite non-potable reuse of graywater treated by graywater reuse and disposal systems for surface drip, subsurface and sprinkler landscape irrigation, ponds (not intended for human contact), vehicle and sidewalk washing, toilet and urinal flushing and fire suppression systems (Or. Admin. R. 340-053). All applicable provisions of the Clean Water Act (CWA) (33 U.S.C. §§ 1251 et seq.), including its implementing regulations, must be met in addition to any state water quality standards. Oregon recognizes three types of graywater, each with a different level of treatment and approved end use applications. Type 1 graywater has no treatment requirements, but is assumed to contain dissolved oxygen if it has been stored 24 hours or less and has no objectionable odor (Or. Admin. R. 340-053). Type 2 and 3 graywater requires treatment systems that must either be certified according to NSF/ANSI Standard 350 or capable of meeting these standards.
Background on NSF/ANSI Standard 350
The National Sanitation Foundation/American National Standards Institute (NSF/ANSI) was originally adopted in 2011 and includes requirements for testing onsite residential and commercial water reuse treatment systems. NSF/ANSI 350 includes requirements for two categories of facilities: residential (up to 1,500 gallons per day) and commercial (systems exceeding 1,500 gallons per day); and four different types of influent: (1) combined black and gray water; (2) gray water only; (3) bathing water only; and (4) laundry water only. The standard covers general non-potable reuse applications, including surface and subsurface irrigation and toilet and urinal flushing. There are two categories of effluent criteria that vary slightly: Class R for single family residential and Class C for multi-family residential and commercial. These effluent quality criteria were developed using the currently existing guidelines codes and regulations, with the goal of meeting the majority of existing codes (although the guidelines do not meet all state codes). Class R includes E. coli water quality requirements not to exceed 14 MPN/100 mL geometric mean and 240 MPN/100 mL single sample maximum and Class C includes E. coli water quality requirements not to exceed 2.2 MPN/100 mL geometric mean and 200 MPN/100 mL single sample maximum.
Types of onsite non-potable reuse approved for use in Oregon
Or. Admin. R. 340-053 defines the following approved onsite non-potable uses:
- Subsurface irrigation of gardens, lawns, landscape plants, food crops, vegetated roofs that do not drain to stormwater management structures and compost (Type 1)
- Landscape ponds not intended for human contact (Type 2)
- Surface drip irrigation of gardens, lawns, living walls, greenhouse and landscape plants (Type 2)
- Sprinkler irrigation of gardens, lawns, living walls, greenhouses and landscape plants (Type 3)
- Wash water for mechanical cleaning of equipment, cars, sidewalks and streets (Type 3)
- Stand-alone fire suppressions system in commercial and residential buildings, toilet or urinal flushing or floor drain trap priming (Type 3)
Water reuse category/type
The various classes of treatment are defined by their respective treatment requirements and applicable performance standards. The respective treatment requirements are summarized for non-potable onsite reuse applications:
- For Type 1 graywater, there are no treatment requirements. The water is assumed to contain dissolved oxygen if it has been stored 24 hours or less and does not have “an objectionable odor” (Or. Admin. R. 340-053).
- For Type 2 graywater, the treatment requirements are secondary treatment and oxidation (Or. Admin. R. 340-053).
- For Type 3 graywater, the treatment requirements are secondary treatment, oxidation and disinfection (Or. Admin. R. 340-053).
Onsite non-potable reuse specifications
Summary of Oregon's Non-potable Reuse Specifications
| Recycled Water Class/Category | Source Water Type | Water Quality Parameter | Specification | Sampling/Monitoring Requirements (Frequency of monitoring; site/ location of sample; quantification methods) |
|---|---|---|---|---|
|
Type 1 graywater (subsurface irrigation) |
Graywater |
There are no treatment requirements for Type 1 graywater, but it must be stored 24 hours or less and have no “objectionable odor.” |
||
|
Type 2 graywater (landscape ponds not intended for human contact, surface drip irrigation) |
Graywater |
5-day biochemical oxygen demand (BOD5) |
≤10 mg/L |
Once a year (for a system producing ≤300 gallons/day) Twice a year (for systems producing >300 gallons/day) |
|
Total suspended solids (TSS) |
≤10 mg/L |
|||
|
Type 3 graywater (sprinkler irrigation, washwater for equipment/cars/ sidewalks, fire suppression systems in buildings, toilet and urinal flushing, trap priming) |
Graywater |
Must meet the treatment requirements for Type 2 graywater and the additional total coliform criteria as specified. |
||
|
Total coliform |
≤2.2 organisms/100 mL (7-day median) ≤23 organisms/100 mL (single sample maximum) |
3 times/week at minimum |
||
Sources = Or. Admin. R. 340-053
Upcoming state law or policy
No upcoming onsite non-potable reuse regulations were found for Oregon.
References:
Clean Water Act, 33 U.S.C. §§ 1251 et seq.
Onsite Residential and Commercial Water Reuse Treatment Systems, NSF/ANSI Standard 350.
Graywater Reuse and Disposal Systems, Or. Admin. R. 340-053.
Please contact us at [email protected] if the information on this page needs updating or if this state is updating or planning to update its laws and policies and we have not included that information on the news page.