Summary of Tennessee's Water Reuse Guideline or Regulation for Centralized Non-Potable Reuse
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
- Applications of centralized non-potable reuse approved for use in Tennessee
- Water reuse treatment category/type
- Additional context and definitions
- Centralized non-potable reuse 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 Tennessee, centralized non-potable reuse The use of recycled water for centralized non-potable reuse where the water does not derive from the same site where it is to be reused. Can include, but is not limited to, toilet flushing, dust control, soil compaction, fire protection, commercial laundries, vehicle washing, street cleaning, snowmaking, and other similar uses. Excludes on-site non-potable water reuse and the use of recycled water for agriculture or landscaping. applications include restricted urban reuse and unrestricted urban reuse. 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 reclaimed water from non-discharging wastewater systems. Tennessee uses the term non-discharging wastewater systems to describe systems in which wastewater is treated to meet the minimum criteria with the intent of being used as reclaimed water for non-potable purposes. The 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
Tennessee approves the reuse of treated municipal wastewater for centralized non-potable reuse including restricted urban reuse and unrestricted urban reuse. 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. Treated municipal wastewater is subject to specifications under Tennessee’s State Operating Permits (SOPs) which authorize operation of non-discharging sewerage systems, given compliance with permit conditions (TN Code § 0400-40-06). Treatment requirements and performance standards are applied for the removal of debris, chemicals and other relevant indicators related to centralized non-potable and are summarized in the table. The technical basis for developing the specifications and/or removal of debris, microbial contaminants, chemicals and other relevant indicators is not explicitly specified.
Applications of centralized non-potable reuse approved for use in Tennessee
Tennessee (TN Code § 0400-40-06) approves of these centralized non-potable reuse applications for recycled treated municipal wastewater:
- Restricted urban reuse: “non-potable reuse of reclaimed wastewater in municipal or suburban settings that is of such quality that public access is controlled or restricted by physical or institutional barriers, such as fencing, advisory signage, or temporal access restrictions.”
- Unrestricted urban reuse: “non-potable reuse of reclaimed wastewater in municipal or suburban settings that is of such quality that public access is not restricted.”
- Purple pipe residential uses (e.g., toilet flushing)
Tennessee does not specify examples of approved restricted or unrestricted urban reuse applications. The state restricts non-potable reuse of reclaimed water for food preparation or incorporation as an ingredient in food or beverages as well as to fill residential or public swimming pools, hot tubs, wading pools or splash pads.
Water reuse treatment category/type
Tennessee does not assign recycled treated municipal wastewater used for centralized non-potable reuse to a category or class. For non-discharging wastewater systems, Tennessee describes that “facilities that treat municipal and/or domestic wastewater, but do not discharge into waters of the state, shall be limited in terms of BOD5 and other pollutants such as NH3-N, NO3-N, and fecal coliform as necessary. Limits shall be set in such a way to assure efficient operation and protection of groundwater” (TN Code § 0400-40-05-.09).
Tennessee defines treatment requirements for non-potable reuse purposes in an urban or suburban setting based on public access to applied treated municipal wastewaters (TN Code § 0400-40-06-.10). Water quality parameters are summarized in the table.
Additional context and definitions
Tennessee defines the reuse of reclaimed water as “the application of reclaimed wastewater of sufficient quality to be reused in non-discharging wastewater systems in a manner protective of human health and the environment” (TN Code § 0400-40-06-.02). Tennessee uses the term non-discharging wastewater systems to describe systems in which wastewater is treated to meet the minimum criteria with the intent of being used as reclaimed water for non-potable purposes (TN Code § 0400-40-06-.02).
For end uses of reclaimed water that fall under non-potable reuse, Tennessee requires applicants seeking authorization to provide these materials engineering design criteria, provide a Reclaimed Wastewater Management Plan (RWMP), end user service agreements and demonstrated availability of reuse alternatives. All piping of non-potable water must be colored purple.
Centralized non-potable reuse specifications
Summary of Tennessee’s Centralized Non-Potable 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)a,b |
|---|---|---|---|---|
|
Unrestricted urban access |
Treated municipal wastewater |
pH |
6.0 to 9.0 Not to fluctuate more than 1.0 unit in this range over a period of 24 hours. |
Weekly Measured at the effluent sampling point of the pump station into the reclaimed water distribution system or as otherwise indicated in the SOP or NPDES permit. |
|
CBOD5 or NH3-N |
10 mg/L CBOD5 |
Weekly Measured at the effluent sampling point of the pump station into the reclaimed water distribution system or as otherwise indicated in the SOP or NPDES permit. |
||
|
NTU or TSS |
5 NTU |
Continuous NTU or daily TSS. Measured at the effluent sampling point of the pump station into the reclaimed water distribution system or as otherwise indicated in the SOP or NPDES permit. |
||
|
Escherichia coli |
23 CFU/100 mL |
Measured at point of release from reclamation system. Once per week measurement frequency for ≤100,000 gal/week application volume. Twice per week measurement frequency for ≥100,000 gal/week application volume. Daily measurement frequency for ≥1,000,000 gal per week application volume. |
||
|
Chlorine residualc |
Minimum of 1 mg/L |
Measured at point of release from reclamation system. Once per week measurement frequency for ≤100,000 gal/week application volume. Twice per week measurement frequency for ≥100,000 gal/week application volume. Daily measurement frequency for ≥1,000,000 gal per week application volume. |
||
|
Restricted urban access |
Treated municipal wastewater |
pH |
6.0 to 9.0 |
Weekly Measured at the effluent sampling point of the pump station into the reclaimed water distribution system or as otherwise indicated in the SOP or NPDES permit. |
|
CBOD5 or NH3-N |
30 mg/L CBOD5 or 10 mg/L NH3-N |
Weekly Measured at the effluent sampling point of the pump station into the reclaimed water distribution system or as otherwise indicated in the SOP or NPDES permit. |
||
|
TSS |
30 mg/L |
Continuous NTU or daily TSS Measured at the effluent sampling point of the pump station into the reclaimed water distribution system or as otherwise indicated in the SOP or NPDES permit. |
||
|
E. coli |
200 CFU/100mL |
Measured at point of release from reclamation system. Once per week measurement frequency for ≤100,000 gal/week application volume. Twice per week measurement frequency for ≥100,000 gal/week application volume. Daily measurement frequency for ≥1,000,000 gal per week application volume. |
||
|
Chlorine residualc |
Minimum of 1 mg/L |
Measured at point of release from reclamation system. Once per week measurement frequency for ≤100,000 gal/week application volume. Twice per week measurement frequency for ≥100,000 gal/week application volume. Daily measurement frequency for ≥1,000,000 gal per week application volume. |
Source = TN Code § 0400-40-03-.03 and TN Code § 0400-40-06-.10
a 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.
b The monitoring frequency may be increased due to special circumstances in the NPDES permit or SOP, as agreed upon in the end user service agreement, or as agreed by the reclaimed wastewater provider.
c Chlorine residual limits apply only upon failure to comply with E. coli limits ≥10% of the time for the previous month.
Upcoming state law or policy
No upcoming regulations pertaining to centralized non-potable reuse applications were found for Tennessee.
References
Clean Water Act, 33 U.S.C. §§ 1251 et seq.
Division of Water Pollution Control, TN Code § 0400-40.
Food Safety Modernization Act (FSMA), 124 Stat. 3885.
General Water Quality Criteria, TN Code § 0400-40-03-.03 (2019).
Permits, Effluent Limitations and Standards, TN Code § 0400-40-05.
State Operating Permits, TN Code § 0400-40-06 (2022).
Tennessee Department of Environment and Conservation (TDEC). 2023a. ARP Competitive Grant Workshop Series: Water Reuse.
TDEC. 2023b. Water Quality State Operating Permits (SOP).
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.