Summary of Oregon's Water Reuse Guideline or Regulation for Landscaping

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
• Water reuse for landscaping approved for use in Oregon
• Water reuse treatment category for landscaping
• Additional context and definitions
• Water reuse for landscaping 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, water reuse for landscaping water reuse for landscapingThe use of recycled water on land to assist in the irrigation of vegetation in residential and non-residential areas. Includes impoundments to store water for irrigation , ornamental vegetation, parks, school yards, sporting facilities (including golf courses), private gardens, roadsides and greenbelts, and cemeteries. Excludes irrigation of areas used for agriculture, commercial reuse applications, or any centralized non-potable reuse. includes parks, playgrounds, school yards, residential landscapes and other landscapes accessible to the public and golf courses, cemeteries, highway medians and industrial or business campuses. The source of water (treated municipal wastewater) 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. This 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 landscaping, including landscape impoundments and the irrigation of parks, residential landscapes, golf courses, industrial and businesses campuses and other publicly accessible landscapes (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. Public access requirements designed to minimize exposure to recycled water are specified for each class of water (Or. Admin. R. 340-055). 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” (Or. Admin. R. 340-055). Treatment requirements and performance standards are applied for the removal of microbial contaminants and other relevant indicators for water reuse for landscaping and are summarized in the table. The technical basis for developing the specifications and/or removals of microbial contaminants, chemicals and other relevant indicators of all classes of treated domestic wastewater effluent is based on California’s Title 22 Water Recycling Criteria (Cal. Code Regs. tit. 22).

Water reuse for landscaping approved for use in Oregon

Or. Admin. R. 340-055 defines the following approved water reuse for landscaping:

• Irrigation of parks, playgrounds, school yards, residential landscapes, other landscapes accessible to the public (Class A)
• Irrigation of golf courses, cemeteries, highway medians, industrial or business campuses (Class C)
• Landscape impoundments (including but not limited to golf course water ponds, non-residential landscape ponds, man-made wetlands) (Class C)

Water reuse treatment category for landscaping

All classes of recycled water must be oxidized and disinfected (Or. Admin. R. 340-055). The classes are differentiated by their specific treatment requirements, turbidity and total coliform requirements:

• Class A recycled water must also be oxidized, filtered and disinfected to achieve a 24-hour mean 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 C recycled water must be oxidized and disinfected to 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

Land application of recycled water requires notification and may require registration with the Oregon Department of Water Resources (Or. Admin. R. 537-132; Or. Admin. 340-055-0017). 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” (Or. Admin. R. 340-055). Oregon defines a landscape impoundment as a body of water used for aesthetic purposes or other function that does not include public contact through activities such as boating, fishing or body-contact recreation (Or. Admin. R. 340-055).

Oregon permits recycled water use in impoundments that are hydraulically isolated from ground and surface waters under its regulations on recycled water use (Oregon DEQ 2009). Recycled water uses in existing impoundments that leak 1/8-inch or more per day to the subsurface require additional consideration of impacts to groundwater and may be subject to administrative rules pertaining to both recycled water and groundwater (Oregon DEQ 2009). A manmade lake or impoundment is defined as a constructed or engineered body of water that is outside of a natural drainage (Oregon DEQ 2009). 

Oregon provides specific site management practices for each class of water. Practices related to impoundments include signage requirements and restrictions associated with the use aerators or decorative fixtures (Or. Admin. R. 340-055). Impoundments must include appropriate warnings against swimming such as: “NO SWIMMING” or (Spanish) “NO NADAR” (Oregon DEQ 2009). Practices related to landscape irrigation include harvesting/irrigation restrictions (Or. Admin. R. 340-055).

Oregon requires municipal recycled water to be distributed through pipes that are appropriately identified by color (i.e., “purple pipe”) and labelled (Or. Admin. R. 340-055). 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 (e.g., employees) for all classes of recycled water and for all end uses. 

Water reuse for landscaping specifications

Oregon DEQ provides a list of approved analytical methods for bacterial and turbidity testing in Table 10 of their Recycled Water Use Rules (Oregon DEQ, 2009).

Summary of Oregon's Water Reuse for Landscaping Specifications

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.

^a Or. Admin. R. 340-055-0012 specifies the frequency of bacteria and turbidity monitoring required for each recycled water Class. These requirements are also described in Oregon DEQ (2009). “For bacteria monitoring, the rule specifies a frequency of daily, 3- times/week, or weekly and includes acceptance criteria such as a median value “based upon the last seven days” (Classes A, B and C). The seven-day median value is intended to be made from the last seven consecutive samples that are representative of the treatment process and operating conditions. The seven consecutive samples do not need to be collected on seven consecutive days. However, collecting seven samples on a single day is not acceptable, nor is selectively choosing seven previous samples out of a larger number. When samples are collected more frequently than specified in the rule (e.g., following an upset in the treatment system or during startup), those should be used in the calculation. For other monitoring parameters, the monitoring frequency should be sufficient to reasonably characterize the recycled water stream” (Oregon DEQ, 2009). 

^b “Analytical testing methods for determining compliance with federal and state water quality standards must comply with 40 CFR Part 136, or if Part 136 does not prescribe a method, then with the most recent addition of Standard Methods for the Examination of Water and Waste Water published jointly by the American Public Health Association, American Water Works Association and Water Pollution Control Federation [OAR 340-041-0061(14)]” (Oregon DEQ, 2009).

^c Specific nephelometric methods include ASTM D1889- 94,00, USGS I-3860-85, EPA Method 180.1 Rev 2.0 (1993), Standard Method 2130 B, or Standard Method Online 2130 B-01 (Oregon DEQ 2009; Table 10).

^d Specific methods include standard methods 9222 D and 9222 D-97 and EPA (1978) for single step membrane filtration; standard methods 9222 B and 9222 B-97, USGS B-0025-8 and EPA (1978) for single step or two step membrane filtration; and standard methods 9221 B and 9221 B-99 and EPA (1978) for most probable number (5 tube, 3 dilution) (Oregon DEQ, 2009; Table 10).

Upcoming state law or policy

No upcoming regulations pertaining to water reuse for landscaping were found for Oregon.

References

Appropriation of Water Generally, Or. Admin. R. 537-132.

Clean Water Act, 33 U.S.C. §§ 1251 et seq.

EPA-Administered Permit Programs: The National Pollutant Discharge Elimination System (NPDES), 40 C.F.R. § 122.

Recycled Water Use, Or. Admin. R. 340-055.

Oregon Department of Environmental Quality (DEQ). 2009. Recycled Water Use.

Recycled Water Reuse, Or. Admin. R. 340-055.

Treatment and Use of Recycled Water, Or. Admin. R. 537-132-0017.

U.S. EPA. 1978. Microbiological Methods for Monitoring the Environment, Water, and Wastes. Environmental Monitoring and Support Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH EPA/600/8-78-017.

Water Recycling Criteria, Cal. Code Regs. tit. 22.

---

Disclaimers

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.