Summary of Oregon's Water Reuse Guideline or Regulation for Centralized Non-potable 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 Treated Municipal Wastewater.
On this page:
- Technical basis
- Applications of centralized non-potable reuse approved for use in Oregon
- Water reuse category/type
- Additional context and definitions
- Centralized 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, centralized non-potable reuse The use of recycled water for centralized non-potable reuse where the water does not derive from the same site where it is to be reused. Can include, but is not limited to, toilet flushing, dust control, soil compaction, fire protection, commercial laundries, vehicle washing, street cleaning, snowmaking, and other similar uses. Excludes on-site non-potable water reuse and the use of recycled water for agriculture or landscaping. applications include commercial car washing, decorative fountains, fire protection and dust control, among others. The source of water treated municipal wastewater Treated wastewater effluent discharged from a centralized wastewater treatment plant of any size. Other terms referring to this source of water include domestic wastewater, treated wastewater effluent, reclaimed water, and treated sewage. is specified by the state as domestic wastewater. 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 use of recycled water for centralized non-potable reuse applications including commercial car washing, decorative fountains, non-residential toilet and urinal flushing, dust control, fire protection and street sweeping (Or. Admin. R. 340-055). 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. Any recycled water use in Oregon requires, at minimum, a National Pollutant Discharge Elimination Systems (NPDES) permit (40 C.F.R. § 122) or a Water Pollution Control Facilities (WPCF) permit and a “Recycled Water Use Plan” (Oregon DEQ, 2009). Class A, B and C recycled water all have total coliform requirements (refer to the specifications summarized in the table) and Class A recycled water has an additional turbidity requirement (refer to the specifications summarized in the table). The technical basis for the removal of turbidity and total coliform are not explicitly specified.
Applications of centralized non-potable reuse approved for use in Oregon
Or. Admin. R. 340-055 defines the following approved centralized non-potable reuse applications:
- Commercial car washing (Class A)
- Decorative fountains when the water is not intended for human consumption (Class A)
- Non-residential toilet or urinal flushing, floor drain trap priming (Class B)
- Fire protection
- Standalone fire suppression systems in commercial and residential buildings (Class B)
- Nonstructural firefighting using an aircraft (Class C)
- Dust control (Class C)
- Street sweeping and sanitary sewer flushing (Class C)
Water reuse category/type
All classes of recycled water must be oxidized and disinfected. The classes are differentiated by their specific treatment requirements, turbidity and total coliform requirements:
- Class A recycled water must also be filtered and achieve a turbidity of ≤2 NTU (7-day median) and ≤10 NTU (single sample maximum) and a total coliform concentration of ≤2.2 organisms/100 mL (7-day median) and ≤23 organisms/100 mL (single sample maximum).
- Class B recycled water must achieve a total coliform concentration of ≤2.2 organisms/100 mL (7-day median) and ≤23 organisms/100 mL (single sample maximum).
- Class C recycled water must achieve a total coliform concentration of ≤23 organisms/100 mL (7-day median) and ≤240 organisms/100 mL (single sample maximum).
Additional context and definitions
Oregon defines recycled water as “any treated effluent from a domestic wastewater treatment system that (as a result of treatment) is suitable for a direct beneficial purpose” (Oregon DEQ, 2009).
Oregon requires municipal recycled water to be distributed through pipes that are appropriately identified by color (i.e., “purple pipe”) and labelled (Oregon DEQ, 2009). Cross connections between a potable water supply and recycled water distribution system are not allowed unless the connection is through an air gap separation approved by Oregon DEQ. Oregon’s Recycled Water Use Rules also require signage to mark recycled water to prevent cross-connections. Signs must be in English and Spanish and contain language indicating recycled water is used and not safe for drinking, for example, “RECYCLED WATER USED – NOT SAFE FOR DRINKING” (Oregon DEQ, 2009). The recycled water generator must actively notify any person that may come into direct contact with recycled water (ex. employees) for all classes of recycled water and for all end uses.
Centralized non-potable reuse specifications
Summary of Oregon's Centralized 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)* |
|---|---|---|---|---|
|
Class A (commercial car washing, decorative fountains) |
Domestic wastewater |
Turbidity |
2 NTU (24-hr mean) 5 NTU (5% of time during a 24-hr period) 10 NTU (single sample maximum) |
Hourly |
|
Total coliform |
2.2 organisms/100 mL (7-day median) 23 organisms/100 mL (single sample maximum) |
Daily |
||
|
Class B (nonresidential toilet and urinal flushing, floor drain trap priming, standalone fire suppression systems in buildings) |
Domestic wastewater |
Total coliform |
2.2 organisms/100 mL (7-day median) 23 organisms/100 mL (single sample maximum) |
Three times/week |
|
Class C (nonstructural firefighting using an aircraft, dust control, street sweeping, sanitary sewer flushing) |
Domestic wastewater |
Total coliform |
23 organisms/100 mL (7-day median) 240 organisms/100 mL (maximum in 2 consecutive samples) |
Once a week |
Source = Or. Admin. R. 340-055; Oregon DEQ (2009)
* Information about sampling and monitoring requirements such as frequency, site and quantification methods not specifically listed in the table was not explicitly specified in the state-specific regulations.
Upcoming state law or policy
No upcoming regulations pertaining to centralized non-potable reuse were found for Oregon.
References:
Clean Water Act, 33 U.S.C. §§ 1251 et seq.
EPA-Administered Permit Programs: The National Pollutant Discharge Elimination System, 40 C.F.R. § 122.
Oregon Department of Environmental Quality (DEQ). 2009. Implementing Oregon’s Recycled Water Use Rules.
Recycled Water Use, Or. Admin. R. 340-055.
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.