Summary of Oklahoma'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 Oklahoma
- 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
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 Oklahoma, 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 towers, once-through cooling systems, make-up water for oil and gas production, closed loop systems, hydraulic fracturing and use within wastewater treatment plants. The source of water 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 municipal 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
Oklahoma approves the use of reclaimed water for industrial reuse applications including as make-up water for oil and gas production, industrial cooling towers, once-through and closed loop cooling systems, hydraulic fracturing and specific uses within wastewater treatment plants (Okla. Admin. Code § 252:656-27). 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. Suppliers of reclaimed water must first obtain a permit from the Oklahoma Department of Environmental Quality (ODEQ), except when using reclaimed water within a wastewater treatment plant pursuant to Category 6 applications (Okla. Admin. Code § 252:656). Treatment requirements and performance standards are applied for the removal of pathogen and chemical contaminants for industrial reuse applications. The technical basis for the removal of pathogen and chemical contaminants is not explicitly specified.
Water reuse industrial applications approved for use in Oklahoma
Okla. Admin. Code § 252:656-27 defines the following approved industrial reuse applications:
- Make-up water for oil and gas production (Category 2)
- Industrial cooling towers (Category 3)
- Once-through cooling systems (Category 3)
- Closed loop systems such as boiler feed water (Category 3)
- Hydraulic fracturing (Category 3)
- Use within wastewater treatment plants, including (Category 6):
- Dilution water for chemicals used in the process such as polymers, coagulants, chlorination or dichlorination
- Mechanical seal water for gas compressors, pumps and other equipment
- Mechanical seal water and cooling water for pumps
- Odor and gas absorption including bio-filters used for odor control
- Centrifuge flushing
- Flushing grit and sludge pipes
- Gravity thickener make-up water
- Supply water for filter backwash
- Headworks screen washing
- Headworks screening washer-compactors
- Belt filter press
- Other reclaimed water that is permanently plumbed to a fixed nozzle and contained within unit operations
Water reuse treatment category for industrial applications
The various classes of treatment are defined by their respective treatment requirements and applicable performance standards. The respective treatment requirements are briefly summarized below:
- For Category 2 reclaimed water, the treatment requirements are secondary treatment, nutrient removal, coagulation, filtration, continuous turbidity measurements using online turbidimeters and disinfection by chlorination or a combination of chlorination and UV. The method of disinfection shall achieve a 5-log removal of Adenovirus type 15, a 5-log removal of Salmonella typhimurium and a 3-log removal of Giardia lamblia.
- For Category 3 reclaimed water, the treatment requirements are secondary treatment, nutrient removal and disinfection by chlorination.
- Category 6 reclaimed water is only allowed for use within the wastewater treatment plant. ODEQ has only permitted Category 6 in larger mechanical wastewater treatment plants with the source provided post-treatment and disinfection (this information is not in the regulation but is currently addressed internally by ODEQ guidance).
Additional context and definitions
Oklahoma defines reclaimed water as “wastewater that has gone through the various treatment processes to meet specific water quality criteria with the intent of being used in a beneficial manner” (Okla. Admin. Code § 252:656).
Oklahoma requires that municipal reclaimed water permittees prevent any physical connections between reclaimed water lines and public water supply lines (Okla. Admin. Code § 252:656). Separation distances are required from public wells (300 feet), private wells (50 feet), waters of the state (25 feet for Category 2 reclaimed water and 50 feet for Category 3 reclaimed water) and property lines (20 feet for Category 2 reclaimed water and 100 feet for Category 3 reclaimed water). As of July 2012, all reclaimed water piping, valves and outlets are required to be colored purple and must be embossed or stamped on opposite sides every three feet with warning language that includes “CAUTION: RECLAIMED WATER – DO NOT DRINK.” For reclaimed water systems installed prior to July 2012, there must be, at minimum, above-ground signs containing the warning language in the previous sentence along with the international “Do Not Drink” symbol every 300 feet, at every change in direction, in the road easement on both sides of every road crossing and at every outlet. For use of Category 6 reclaimed water within wastewater treatment plants, yard hydrants and hose bibs must have signs containing cautionary language noting the use of water is restricted to the confines of the plant for the listed uses (Okla. Admin. Code § 252:627).
Water reuse for industrial applications specifications
Summary of Oklahoma's Water Reuse for Industrial Applications 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)* |
|---|---|---|---|---|
|
Category 2 (Make-up water for oil and gas production) |
Municipal wastewater |
Turbidity |
≤2 NTU (daily average) |
Continuous monitoring. The daily mean operating filter effluent turbidity (continuously monitored) is calculated as the average of turbidity measures at ≤ 1.2-hour intervals over 24 hours and must be reported monthly. The maximum 24-hour turbidity must be based on highest measure from continuous monitoring taken at ≤ 1.2-hour intervals over 24 hours. |
|
Chlorine residual (at POEa to distribution system) |
≥1.0 ppm (free available chlorine residual) or “the chlorine residual at the POE shall be at a level to prevent growth of slime and regrowth of pathogens in the distribution and storage systems as determined by an approved chlorine decay rate model pursuant to OAC 252:656-3-4 (b)(7)(C)” |
Continuous monitoring | ||
| Chlorine residual (at end-of-pipe) | ≥0.20 mg/L (free available chlorine residual) or ≥0.50 mg/L (combined chlorine residual) |
Daily | ||
| Fecal coliform | 0 CFU/100 mL (in four of the last seven daily samples) ≤23 CFU/100 mL (single sample maximum) |
Daily | ||
| Total N | "≤ most stringent agronomic rate" | Monthly | ||
| Total P | "≤ most stringent agronomic rate" | Monthly | ||
| 5-day carbonaceous biochemical oxygen demand (CBOD5) | <5 mg/L | Weekly | ||
| Adenovirus type 15 | 5-log removal or inactivation | The method of disinfection must achieve these removals | ||
| Salmonella typhimurium | 5-log removal or inactivation | |||
| Giardia lamblia | 3-log removal or inactivation | |||
|
Category 3 (Industrial cooling towers; Once-through cooling systems; Closed loop systems such as boiler feed water; Hydraulic fracturing) |
Municipal wastewater |
Chlorine residual |
≥0.20 mg/L (free available chlorine residual) |
Every 12 hours, measured at the POE |
|
Fecal coliform |
<200 coli/100 mL (monthly geometric mean) |
3 times/week | ||
| Total N | "≤ most stringent agronomic rate" | Monthly | ||
| Total P | "≤ most stringent agronomic rate" | Monthly | ||
| 5-day biochemical oxygen demand (BOD5) or 5-day carbonaceous biochemical oxygen demand (CBOD5) | <20 mg/L | Weekly | ||
| Category 6 (Use within wastewater treatment plants) | Municipal wastewater | ODEQ has only permitted Category 6 in larger mechanical wastewater treatment plants with the source provided post-treatment and disinfection. This language is not in the regulation but currently addressed by internal ODEQ guidance. | ||
Source= Okla. Admin. Code § 252:656 and § 252:627
* 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 POE= point of entry.
Upcoming state law or policy
No upcoming regulations related to industrial water reuse were found for Oklahoma.
References:
Clean Water Act, 33 U.S.C. §§ 1251 et seq.
Oklahoma Department of Environmental Quality. 2015. Title 252. Chapter 656. Water pollution control facility construction standards. Subchapter 27. Water Reuse.
Oklahoma Department of Environmental Quality. 2015. Title 252. Chapter 627. Operation and Maintenance of Water Reuse Systems. Appendix A. Testing Frequency and Limits for Water Reuse Systems.
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.