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

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 impoundments approved for use in Oregon
• Water reuse treatment category for impoundments
• Additional context and definitions
• Water reuse for impoundments specifications (table)
• Upcoming state law or policy
• References
• Disclaimer

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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 reused for impoundments impoundmentsThe use of recycled water in an impoundment (body of water within an enclosure). This includes both unrestricted (use of reclaimed water in an impoundment in which no limitations are imposed on body-contact water recreation activities) and restricted (use of reclaimed water in an impoundment where body contact is restricted). Includes recreational impoundments, aesthetic impoundments, and ornamental impoundments with and without public access. Excludes landscape impoundments and storage of recycled water intended for other specific reuse applications (e.g., for agricultural irrigation). include restricted and nonrestricted recreational impoundments. 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 municipal wastewater. The write-up below 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 municipal wastewater for impoundment-related reuse applications including restricted recreational impoundments, nonrestricted recreational impoundments and impoundments that are hydraulically isolated from ground and surface waters (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 an Oregon Department of Environmental Quality (DEQ) approved “Recycled Water Use Plan” (Or. Admin. R. 340-055). Public access requirements, which are designed to minimize exposure to recycled water, are specified for each class of water (Or. Admin. R. 340-055). Impoundments with nonrestricted recreation have more stringent performance standards than impoundments with restricted recreation. Treatment requirements and performance standards are applied for the removal of microbial contaminants and other relevant indicators related to impoundments 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 impoundments approved for use in Oregon

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

• Nonrestricted recreational impoundments (including but not limited to recreational lakes, water features accessible to the public and public fishing ponds) (Class A)
• Restricted recreational impoundments (Class B)

Water reuse treatment category for impoundments

The classes of reclaimed water 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, a turbidity ≤5 NTU for 5% of time during a 24-hour period and a single sample maximum of ≤10 NTU; as well as 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 be oxidized and disinfected to 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 be oxidized and disinfected to achieve a total coliform concentration of ≤23 organisms/100 mL (7-day median) and ≤240 organisms/100 mL (maximum in two consecutive samples).

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” (Or. Admin. R. 340-055). Oregon defines a “restricted recreational impoundment” as a constructed body of water that is limited to fishing, boating and other non-body contact water recreation activities, while a “nonrestricted recreational impoundment” is defined as a constructed body of water for which there are no limitations on body-contact water recreation activities (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 of aerators or decorative fixtures (Or. Admin. R. 340-055). Impoundments or recreational features must include appropriate warnings against swimming such as: “NO SWIMMING” or (Spanish) “NO NADAR” (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 (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 (i.e., employees) for all classes of recycled water and for all end uses.  

Water reuse for impoundments specifications

Summary of Oregon's Water Reuse for Impoundments 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 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 reuse regulations related to impoundments 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.

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

Oregon Department of Environmental Quality (DEQ). 2009. OAR 340-055-0005 to OAR 340-055-0030 Recycled Water Use.

USEPA. 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.

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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.