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

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 industrial applications approved for use in Oregon
• Water reuse treatment category for industrial applications
• Additional context and definitions
• Water reuse for industrial applications 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 industry water reuse for industryThe use of recycled water for industrial applications, often created at the industrial facility. This includes recycled water generated through onsite processes such as boiler water, cooling water, manufacturing water, and oil and gas production, as well as recycled water generated offsite and imported elsewhere for industrial reuse applications. includes reuse for industrial cooling. The source of water (treated municipal wastewater) treated municipal wastewaterTreated 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 on this page 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 industrial applications including as industrial cooling water (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. Any recycled water use in Oregon requires, at minimum, a National Pollutant Discharge Elimination Systems (NPDES) permit (40 CFR 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 and are summarized in the table. The technical basis for the derivation of turbidity and total coliform removals and water quality issues related to Legionella for Class C recycled waters is California’s Title 22 Water Recycling Criteria (Cal. Code Regs. tit. 22).

Water reuse industrial applications approved for use in Oregon

Or. Admin. R. 340-055 defines the following approved industrial applications:

• Industrial cooling (Class C)

The Oregon Department of Environmental Quality (DEQ) may authorize other uses not specified in the regulations through the facility’s water quality permit (Or. Admin. R. 340-055-0016).

Water reuse treatment category for industrial applications

Recycled water must be oxidized and disinfected. The respective treatment requirements are briefly summarized for industrial applications:

• 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).

The Oregon Department of Human Services identified Legionella as a concern in cooling water systems (Or. Admin. R. 340-055). Additional disinfection requirements for the control of Legionella are specified in the table.

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).

In Oregon, if aerosols are generated when using recycled water for an industrial application, the aerosols must not create a public health hazard and public exposure to aerosols generated from cooling water systems must be considered (Or. Admin. R. 340-055). Specific considerations include, but are not limited to, the following (Or. Admin. R. 340-055

• “Systems that create a mist must be operated with drift eliminators and/or biocides if public or employees are potentially exposed to the mist [(California Title 22, 13552.8(a)(3)]. 
• Employee education programs can also be used as a strategy for promoting awareness of aerosol generation in the workplace.
• If workplace hazards are of particular concern with a reuse application, the permit writer may need to confer with Oregon OSHA for additional guidance.”

Specifically, Oregon has identified Legionella as a potential concern in cooling water systems (e.g., evaporative cooling). For proposed cooling system uses, the type of system (e.g., cooling tower, spray, condenser), the biocide used, details on the type of drift eliminator and the potential for employee or public exposure and mitigation measures to be employed must be included in the project’s recycled water engineering report (Or. Admin. R. 340-055). Other water quality issues to be considered include ensuring the use of disinfectant residual and system cleaning is conducted on a regular schedule, evaluating scaling and salt buildup from evaporation and concentration by limiting cycles of concentration of using nanofiltration and cross-connection and dual plumbing (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 (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. 

Water reuse for industrial applications specifications

Summary of Oregon's Water Reuse for Industrial Applications Reuse 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 median value “based upon the last seven days” (Class 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 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 related to water reuse for industry 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.

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.

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

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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.