Summary of Nevada's Water Reuse Guideline or Regulation for Agriculture
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.
- Technical basis
- Water reuse for agriculture approved for use in Nevada
- Water reuse treatment category for agriculture
- Additional context and definitions
- Water reuse for agriculture 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 Nevada, water reuse for water reuse for agricultureThe use of recycled water to land to assist in the production of both commercially and non-commercially processed food crops consumed by humans or livestock and non-food crops. Includes pasture for milking and non-milking animals, fodder, fiber, and seed crops, vineyards, orchards, ornamental nursery stock, Christmas trees, and silviculture. Excludes consumption by livestock, onsite non-potable reuse, and landscaping. includes irrigation of food crops, including edible food crops; watering of nursery stock if public access to the area of use is restricted; surface irrigation for agricultural purposes and cultivation of fruit- or nut-bearing trees; subsurface irrigation of land used for agricultural purposes if public access is restricted; and spray irrigation of land used for agricultural purposes if public access to the area of use is prohibited and if a buffer zone of not less than 800 feet is maintained. 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 municipal wastewater. 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
Nevada approves the use of reclaimed water for agriculture, including irrigation of food crops, watering of nursery stock (where public access is restricted), surface irrigation for agricultural purposes and for the cultivation of fruit-bearing or nut-bearing trees, subsurface irrigation of land used for agricultural purposes if public access is restricted and spray irrigation of land used for agricultural purposes, if public access is prohibited and requirements for a buffer zone are maintained (Nev. Admin. Code § 445A). 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). All categories of reclaimed water must receive secondary treatment and meet specific pH, TSS and BOD requirements. Treatment requirements and performance standards are applied for the removal of microbial contaminants, chemicals and other relevant indicators related to agriculture and are summarized in the table. The technical basis for developing the specifications and/or removals of microbial contaminants, chemicals and other relevant indicators is not explicitly specified. However, buffer zone requirements for the use of reclaimed water are based on human exposure to aerosols. For example, the most-restrictive buffer of 800 feet for Reuse Category E effluent assumes allowing center-pivot irrigation of non-disinfected effluent in rural, agricultural areas.
Water reuse for agriculture approved for use in Nevada
Nev. Admin. Code § 445A defines the following approved water reuse for agriculture:
- Irrigation of food crops, including edible food crops (Reuse Category A)
- Watering of nursery stock if public access to the area of use is restricted (Reuse Category C)
- Surface irrigation (defined as irrigation using a flood irrigation system or a drip irrigation system) for agricultural purposes (Reuse Category D)
- Surface irrigation for the cultivation of fruit-bearing or nut-bearing trees (Reuse Category D)
- Subsurface irrigation of land used for agricultural purposes if public access is restricted (Reuse Category D)
- Spray irrigation (defined as irrigation using sprinklers that are located above the ground surface) of land used for agricultural purposes if public access to the area of use is prohibited and if a buffer zone of not less than 800 feet is maintained (Reuse Category E)
Nevada permits the use of Category A+ recycled water for the irrigation of edible food crops and any other reuse activity approved for reuse category A, B, C, D or E (Nev. Admin. Code § 445A). For specifications for Category A+, please see the webpage for “potable water reuse.”
Water reuse treatment category for agriculture
All reuse categories require, at minimum, secondary treatment that achieves a pH of 6–9, a TSS concentration of ≤30 mg/L and a BOD5 concentration of ≤30 mg/L. The reuse categories differ by their bacteriological quality requirements.
An engineered, disinfection step is required for Category A water involving either chlorination, ultraviolet disinfection or ozonation. Some Category A facilities employ additional filtration following secondary clarification (Nevada DEP, personal communication, May 3, 2022).
Category E facilities are generally limited to lagoon treatment facilities wherein undisinfected effluent is applied on a nearby agricultural tract for flood irrigation of non-edible (forage) crop (Nevada DEP, personal communication, May 3, 2022).
Recycled water applied via subsurface irrigation and spray irrigation is generally treated to the same biological and disinfection standards (Nevada DEP, personal communication, May 3, 2022). Nevada does not permit the subsurface irrigation of untreated, commercial graywater.
Additional context and definitions
In Nevada, reclaimed water is defined as “sewage that has been treated by a physical, biological, or chemical process, which is intended for a use defined in Nev. Admin. Code § 445A.276 to 445A.2771, inclusive, and that meets the corresponding water quality criteria for the specified use” (Nev. Admin. Code § 445A).
A person using reclaimed water for spray irrigation is required to conduct the irrigation in a manner that inhibits the reclaimed water spray from drifting beyond the area of use or the buffer zone, if any (Nev. Admin. Code § 445A.2754). Nevada establishes the size of a given buffer zone and buffer zone requirements are based on human exposure to aerosols (Nev. Admin. Code § 445A.2756). For example, the most-restrictive buffer of 800 feet for Category E effluent assumes allowing center-pivot irrigation of non-disinfected effluent in rural, agricultural areas.
Nevada requires signs to be posted along the outer perimeter of the area of municipal reclaimed water use that warn the public that reclaimed water is in use in the area and that contact with the reclaimed water should be avoided (Nev. Admin. Code § 445A). The pipe infrastructure conveying the reclaimed water must be identified by color marking or a metal tag and all reclaimed water outlets, like faucets and hose connections, must be identified at the point of use.
Water reuse for agriculture specifications
Summary of Nevada's Water Reuse for Agriculture Specifications
Recycled Water Class/Category | Source Water Type | Water Quality Parameter | Specification | Sampling/Monitoring Requirements (Frequency of monitoring; site/ location of sample; quantification methods)* |
---|---|---|---|---|
Reuse Category A (Irrigation of food crops) |
Municipal wastewater |
Same pH, BOD5 and TSS requirements as Reuse Category D water. |
||
Total coliform |
≤2.2 CFU or MPN/100 mL (30-day geometric mean) ≤23 CFU or MPN/100 mL (single sample maximum) |
Reclaimed water must meet these bacteriological quality requirements prior to the reuse activity |
||
Nitrogena |
Not specified |
Not specified |
||
Phosphorus |
Not specified |
Not specified |
||
Reuse Category C (Watering of nursery stock where public access is restricted) |
Municipal wastewater |
Same pH, BOD5 and TSS requirements as Reuse Category D water. |
||
Fecal coliform |
≤23 CFU or MPN/100 mL (30-day geometric mean) ≤240 CFU or MPN/100 mL (single sample maximum) |
Reclaimed water must meet these bacteriological quality requirements prior to the reuse activity |
||
Nitrogena |
Not specified |
Not specified |
||
Phosphorus |
Not specified |
Not specified |
||
Reuse Category D (Surface irrigation for agricultural purposes and the cultivation of fruit-bearing or nut-bearing trees; Subsurface irrigation of land used for agricultural purposes where public access is restricted) |
Municipal wastewater |
pH |
6–9 (30-day average) |
After secondary treatment |
5-day inhibited biological oxygen demand (BOD5) |
≤30 mg/L (30-day average) |
|||
Total suspended solids (TSS) |
≤30 mg/L (30-day average) |
|||
Fecal coliform |
≤200 CFU or MPN/100 mL (30-day geometric mean) ≤400 CFU or MPN/100 mL (single sample maximum) |
Reclaimed water must meet these requirements prior to the reuse activity |
||
Nitrogena |
Not specified |
Not specified |
||
Phosphorus |
Not specified |
Not specified |
||
Reuse Category E (Spray irrigation of land used for agricultural purposes if public access to the area of use is prohibited and if a buffer zone of not less than 800 feet is maintained) |
Municipal wastewater |
pH |
6–9 (30-day average) |
After secondary treatment |
5-day inhibited biological oxygen demand (BOD5) |
≤30 mg/L (30-day average) |
|||
Total suspended solids (TSS) |
≤30 mg/L (30-day average) |
|||
Fecal coliform |
No limit |
Not specified |
||
Nitrogena |
Not specified |
Not specified |
||
Phosphorus |
Not specified |
Not specified |
Source= Nev. Admin. Code § 445A
* 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 The use of non-denitrified reclaimed water requires application at the agronomic, uptake rate of the crop or landscape to avoid nitrogen overapplication and leaching (personal communication).
Upcoming state law or policy
No upcoming regulations pertaining to water reuse for agriculture were found for Nevada.
References
Clean Water Act, 33 U.S.C. §§ 1251 et seq.
Food Safety Modernization Act (FSMA), 124 Stat. 3885.
Water Controls, Nev. Admin. Code § 445A.
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