Summary of Idaho'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.

On this page:

• Technical basis
• Water reuse for agriculture approved for use in Idaho
• Water reuse treatment category for agriculture
• Additional context and definitions
• Water reuse for agriculture specifications (table)
• Upcoming state law or policy
• References
• Disclaimer

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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 Idaho, water reuse for agriculture water reuse for agricultureThe use of recycled water for production of both crops for human consumption and non-food crops of commercial value. This reuse application excludes consumption by livestock, onsite non-potable reuse, and landscaping. includes pasture for animals producing milk for human consumption; orchards and vineyards during the fruiting season; processed food crops; ornamental nursery stock or Christmas trees; sod and seed crops not intended for human ingestion; pasture for animals not producing milk for human consumption; fodder and fiber crops; and commercial timber and firewood. The source of water (treated municipal wastewater) 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. 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

Idaho approves the reuse of recycled water for agriculture, including irrigation of processed food crops for human consumption, fodder and fiber crops, ornamental nursery stock, sod and seed crops, orchards and vineyards and pasture for animals, including those that produce milk for human consumption (Idaho Admin. Code r. 58.01.17). Idaho requires the establishment of buffer distances from reuse facilities to protect public health by: 1) limiting the public’s exposure to recycled water and the conditions associated with reuse facilities and 2) ensuring that the use of recycled water is restricted to within the physical boundaries of the reuse facility (Idaho Admin. Code r. 58.01.17). All applicable provisions of the Clean Water Act (CWA) (33 U.S.C. §§ 1251 et seq.), including its implementing regulations, must be met. Additionally, commercial food crop growing operations may be subject to any relevant rule requirements under the Food Safety Modernization Act (FSMA) (124 Stat. 3885). 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. Idaho Department of Environmental Quality uses California’s Title 22 Water Recycling Criteria (Cal. Code Regs. tit. 22) as the technical basis for the derivation of total coliform removals, virus inactivation and turbidity requirements (defined in the table).

Water reuse for agriculture approved for use in Idaho

Idaho Admin. Code r. 58.01.17 defines the following approved water reuse for agriculture, which consists of the irrigation of: 

• Pasture for animals producing milk for human consumption (Class C)
• Orchards and vineyards during the fruiting season, if no fruit harvested for raw use comes in contact with the irrigation water or ground or will only contact the inedible portion of raw food crops (Class C)
• Processed food crops or “food crops that must undergo commercial pathogen-destroying processing before being consumed by humans” (Class D)
• Ornamental nursery stock or Christmas trees (Class D)
• Sod and seed crops not intended for human ingestion (Class D)
• Pasture for animals not producing milk for human consumption (Class D)
• Fodder and fiber crops (Class E)
• Commercial timber and firewood (Class E)

Water reuse treatment category for agriculture

The various classes of treatment are defined by their respective treatment requirements and applicable performance standards. The respective treatment requirements are briefly summarized regarding water reuse for agriculture:

• For Class C and Class D recycled water, municipal wastewater is required to be oxidized and adequately disinfected to meet the total coliform requirements for Class C or Class D recycled water, respectively, in the table (Idaho Admin. Code r. 58.01.17.601).
• For Class E recycled water, municipal wastewater “must meet at least primary effluent quality” and there are no disinfection requirements or applicable coliform standard (Idaho Admin. Code r. 58.01.17.601). 

Additional context and definitions

Idaho defines recycled water as “water that has been treated by a wastewater treatment system and is used in accordance with the rules” in Idaho Admin. Code r. 58.01.17. 

Idaho requires that all new buried pipe, exposed and above ground pipe conveying Class A municipal recycled water must be colored purple. For Class A and Class B municipal recycled water, signs must be posted at the area of use that state “Caution: Recycled Water - Do Not Drink” in both English and Spanish to indicate that recycled water is being used and is not safe for drinking or human contact (Idaho Admin. Code r. 58.01.17). For Class C and Class D municipal recycled water, signs must be posted at the area of use that state “Caution: Recycled Water - Do Not Enter” in both English and Spanish to indicate that recycled water is being used and is not safe for drinking or human contact (Idaho Admin. Code r. 58.01.17).

In determining buffer distances for inclusion in a reuse permit, Idaho considers the characterization of the recycled water, the irrigation method, the physical or vegetative barriers, microbial risk assessments, applicable best management practices, environmental conditions (e.g., wind speed and direction) and any other relevant information (Idaho Admin. Code r. 58.01.17).

Water reuse for agriculture specifications

Summary of Idaho's Water Reuse for Agriculture Specifications

Source= Idaho Admin. Code r. 58.01.17

* 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 Idaho provides loading limits in place of concentration limits for nitrogen and monitoring typically occurs monthly. Requirements are specified in the associated permit on a case-by-case basis, for more information contact the state. 

^b Phosphorus requirements are specified in the associated permit on a case-by-case basis and are determined based on groundwater conditions and connectivity, surface water proximity and connectivity and soil conditions (for more information, contact the state). In some cases, ongoing monitoring is required (for more information, contact the state).

Upcoming state law or policy

No upcoming regulations pertaining to water reuse for agriculture were found for Idaho. Guidance on buffer distances related to the use of recycled water is currently being updated.

References

Clean Water Act, 33 U.S.C. §§ 1251 et seq.

Food Safety Modernization Act (FSMA), 124 Stat. 3885.

Recycled Water Rules, Idaho Admin. Code r. 58.01.17.

Water Recycling Criteria, Cal. Code Regs. tit. 22.

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Disclaimers

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.