Summary of Rhode Island'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 Rhode Island
- 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 Rhode Island, water reuse for 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 irrigation of areas where public exposure is controlled or likely . The source of water 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 treated wastewater effluent. 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
Rhode Island approves the reuse of treated wastewater effluent for landscaping, including the use of treated wastewater for irrigation of areas where “public exposure is controlled” and “where public exposure is likely.” 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 relevant rule requirements under the Food Safety Modernization Act (FSMA) (124 Stat. 3885). “Wastewater being diverted from a source wastewater treatment facility” are 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 water reuse for landscaping and are summarized in the table. Rhode Island DEM (2012) states that water quality “parameters are general values based on water quality/health protection. DEM’s Division of Agriculture may require more stringent site-specific parameters and conditions.” 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 for landscaping approved for use in Rhode Island
Rhode Island DEM (2012) defines the following approved water reuse for landscaping:
- Irrigation of areas where public exposure is controlled, such as golf courses or parks that have controlled times of operation (Restricted Reuse: Irrigation Only)
- Irrigation of areas where public exposure is likely, such as parks that have no fixed hours of operation or commercial landscaping (Unrestricted Reuse: Irrigation Only)
Water reuse treatment category for landscaping
The treatment requirements for “wastewater being diverted from a source wastewater treatment facility” to be used for Restricted Reuse Irrigation in areas where public access is controlled and for Unrestricted Reuse Irrigation in areas where public access is likely to include the use of chlorine or UV (Rhode Island DEM, 2012).
- For Restricted Reuse Irrigation, the minimum chlorine residual limit is 0.5 mg/L after 30 minutes of contact time. The UV dosage is 75 mJ/cm2 at the maximum day flow rate. Treated wastewater effluent that does not meet chlorine residual limits cannot be diverted for use.
- For Unrestricted Reuse Irrigation, the minimum chlorine residual limit is 1 mg/L after 30 minutes of contact time. The UV dosage is 100 mJ/cm2 at the maximum day flow rate. Treated wastewater effluent that does not meet chlorine residual limits cannot be diverted for use.
Additional context and definitions
Rhode Island requires that proper signage be visible during periods of water reuse and until 20 days after the suspension of seasonal irrigation. “All signage must be submitted for review as part of the application for an Order of Approval. Signage must: (a) state that reclaimed wastewater is in use and any visible waters should be avoided; (b) state any approved restrictions on times or conditions for reuse application; (c) include contact information for the Rhode Island DEM to report possible non-compliance; and (d) be placed in appropriately visible location or locations” (Rhode Island DEM, 2012).
Water reuse for landscaping specifications
Summary of Rhode Island's Water Reuse for Landscaping 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)* |
|---|---|---|---|---|
|
Restricted Reuse: Irrigation Only (Areas where public exposure is controlled, such as golf courses or parks that have controlled times of operation) |
Treated wastewater effluent |
Total residual chlorine |
0.5 mg/L (30-minute contact time) |
Must be met with a single sample |
|
Total suspended solids (TSS) |
8 mg/L |
TSS must be achieved prior to final chlorination on a continuous basis, as verified through continuous monitoring of turbidity (NTU monitoring is sufficient provided facility can show equivalence to 8 mg/L) |
||
|
Turbidity |
2 NTU |
TSS must be achieved prior to final chlorination on a continuous basis, as verified through continuous monitoring of turbidity (NTU monitoring is sufficient provided facility can show equivalence to 8 mg/L); Must be met with a single sample |
||
|
Biochemical oxygen demand (BOD) |
10 mg/L |
Five-day average |
||
|
Fecal coliform |
23 (unit not provided)/100 mL |
Five-day average |
||
|
Total nitrogen |
10 mg/L |
Five-day average |
||
|
pH |
6–9 |
Not specified |
||
|
Phosphorus |
Not specified |
|||
|
Unrestricted Reuse: Irrigation Only (Areas where public exposure is likely, such as parks that have no fixed hours of operation or commercial landscaping) |
Treated wastewater effluent |
Total residual chlorine |
1 mg/L (30-minute contact time) |
Must be met with a single sample |
|
Total suspended solids (TSS) |
5 mg/L |
TSS must be achieved prior to final chlorination on a continuous basis, as verified through continuous monitoring of turbidity (NTU monitoring is sufficient provided facility can show equivalence to 5 mg/L) |
||
|
Turbidity |
2 NTU |
TSS must be achieved prior to final chlorination on a continuous basis, as verified through continuous monitoring of turbidity (NTU monitoring is sufficient provided facility can show equivalence to 5 mg/L); Must be met with a single sample |
||
|
Biochemical oxygen demand (BOD) |
10 mg/L |
Five-day average |
||
|
Fecal coliform |
2.2 (unit not provided)/100 mL |
Five-day average |
||
|
Total nitrogen |
10 mg/L |
Five-day average |
||
|
pH |
6–9 |
Not specified |
||
|
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.
Upcoming state law or policy
No upcoming regulations pertaining to water reuse for landscaping were found for Rhode Island.
References
Clean Water Act, 33 U.S.C. §§ 1251 et seq.
Food Safety Modernization Act (FSMA), 124 Stat. 3885.
Rhode Island Department of Environmental Management (DEM). 2012. State of Rhode Island and Providence Plantations Department of Environmental Management Application Guidance for Wastewater Reuse Projects.
Please contact us at waterreuse@epa.gov 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.