Summary of Rhode Island'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 Rhode Island
- 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 Rhode Island, 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 cooling water for cooling towers. 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 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
Rhode Island approves the use of recycled water for industrial applications including non-contact cooling water (Rhode Island DEM, 2012). 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. “Wastewater being diverted from a source wastewater treatment facility” is required to meet treatment requirements “based on the intended use at the point of diversion or the point of use, as appropriate” (Rhode Island DEM, 2012). Treatment requirements and performance standards are applied for the removal of microbial contaminants, chemicals and other relevant indicators for industrial-related applications and are summarized in the table. Water quality parameters set forth by Rhode Island Department of Environmental Management (DEM) (2012) for non-contact cooling water discharged to the atmosphere “are based on air quality/human health protection. The DEM Office of Air Resources may require more stringent site-specific parameters and conditions. General requirements include compliance with RIAPC No.22 and any other applicable air regulations” (Rhode Island DEM, 2012). Additional information on the technical basis for developing the specifications and/or removals of microbial contaminants, chemicals and other relevant indicators is not explicitly specified.
Water reuse industrial applications approved for use in Rhode Island
Rhode Island DEM (2012) defines the following approved industrial applications:
- Non-contact cooling water, including use in cooling towers for industrial, non-contact heat-transfer with no discharge to state waters
Water reuse treatment category for industrial applications
The treatment requirements for “wastewater being diverted from a source wastewater treatment facility” to be used for non-contact cooling water include the following:
- A total chlorine residual of 1.0–3 mg/L at the terminal point of the water reuse supply pipeline and a free chlorine residual of 0.5–0.7 mg/L in the cooling tower basin with a minimum chlorine contact time of 3 hours (high efficiency drift eliminators so that drift is limited to 0.0005% of the circulating water flow).
- Phosphorous treatment prior to filtration so that the nutrient load is minimized within the cooling tower basin if necessary.
- The use of ultra-filtration to ensure compliance with the limits for total suspended solids and fecal coliform presented in the table unless there is adequate storage of treated water or an alternative water source.
The use of chromium-based biocides and/or chromium-based fungicides are prohibited in the cooling tower.
Additional context and definitions
None.
Water reuse for industrial applications specifications
Summary of Rhode Island's Water Reuse for Industrial Applications Reuse Specifications
| Recycled Water Class/Category (Approved Uses) | Source Water Type | Water Quality Parameter | Specification | Sampling/Monitoring Requirements (Frequency of monitoring; site/ location of sample; quantification methods)* |
|---|---|---|---|---|
|
Non-contact cooling water (cooling towers for industrial, non-contact heat-transfer with no discharge to state waters) |
Treated wastewater effluent |
Total residual chlorine |
1.0–3.0 mg/L (3 hour contact time)a |
Must be met with a single sample |
|
Free chlorine residual |
0.5–0.7 mg/L (3 hour contact time)a |
Must be met with a single sample |
||
|
Total suspended solids (TSS)b |
Must correspond to 5 mg/L |
TSS must be achieved prior to final chlorination on a continuous basis, as verified through continuous monitoring of turbidity; Sampling frequency determined as part of project review |
||
|
Turbidity |
Must correspond to 5 mg/L |
Continuous monitoring |
||
|
Fecal coliformb |
0.0/100 mL |
Level at the terminal point of the cooling water pipeline must not exceed zero. This limit will be verified by a testing protocol specified in the air permit; Sampling frequency determined as part of project review |
||
|
Phosphorus |
Not specified |
Not specified |
Source = Rhode Island DEM (2012)
* 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 High efficiency drift eliminators so that drift is limited to 0.0005% of the circulating water flow.
b Storage or alternative water source adequate to maintain operation if TSS or fecal coliform is not in compliance.
Upcoming state law or policy
No upcoming regulations related to water reuse for industry were found for Rhode Island.
References
Air Toxics, 250 R.I. Gen. Laws § 120-05-22.
Clean Water Act, 33 U.S.C. §§ 1251 et seq.
Rhode Island Department of Environmental Management. 2012. Guidance for wastewater reuse projects.
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.