Summary of Minnesota's Water Reuse Guideline or Regulation for Stormwater 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 Stormwater.

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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 Minnesota, industrial applications include fire suppression, industrial cooling water, washing and process and boiler water. Onsite non-potable water reuse applications include toilet flushing, cooling and washing. The source of water stormwaterPrecipitation that is collected from land or impervious surfaces at a district or regional scale for the purpose of beneficial reuse. Rainwater collection at the building scale is classified separately under 'onsite collected waters.’ is specified by the state as water made by rainfall or snowmelt that causes runoff. 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

Minnesota approves the capture and use of stormwater for industrial reuse applications including fire suppression, industrial washing, cooling water makeup and process and boiler water (MPCA, 2023). 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 or industry-specific standards. Minnesota does not regulate the capture, storage or treatment of stormwater; however, the state regulates select distribution routes of captured stormwater (MDH, 2018) and provides risk-based guidance on stormwater (MPCA, 2023). In Minnesota, a state water appropriation permit is not required if collection is from constructed management facilities for stormwater (e.g., cisterns, ponds, basins, holding tanks) that have been designed according to best management practices in accordance with local, state or federal requirements (Minn. Stat. § 103G.271). Permits are required for the withdrawal of stormwater from water features that do not meet this definition (MDH, 2018).

Treatment requirements and performance standards are not described for the removal of debris, microbial contaminants, chemicals and other relevant indicators related to industrial reuse. However, the Minnesota Stormwater Manual indicates water quality treatment considerations for stormwater were based on the Minnesota Plumbing Code rainwater end-use requirements (Minn. Stat. § 4714.1601) and the National Water Research Institute (NWRI) Independent Advisory Panel findings (MPCA, 2022). The technical basis for developing the specifications and/or removal of debris, microbial contaminants, chemicals and other relevant indicators is provided by the NWRI document (MPCA, 2022).

Water reuse industrial applications approved for use in Minnesota

Minnesota does not provide a complete list of approved industrial water reuse applications for collected stormwater. The Minnesota Stormwater Manual (2023) describes common industrial uses of stormwater including:

  • Fire suppression (e.g., sprinkler systems)
  • Industrial washing applications (e.g., equipment)
  • Cooling water or cooling water makeup supply
  • Process and boiler water

Water reuse treatment category for industrial applications

Minnesota does not assign collected stormwater used for industrial reuse purposes to a category or class. Instead, Minnesota uses a use system matrix (provided in the Minnesota Stormwater Manual) that categorizes common beneficial indoor and outdoor uses of stormwater by level of effort for treatment and associated health criteria level (MPCA, 2023).

The Minnesota Stormwater Manual (2023) defines that level of effort categories are assigned based on risk of exposure at point of use (e.g., restricted vs. unrestricted public access). The Minnesota Stormwater Manual (2023) defines that level of effort categories are assigned based on risk of exposure at point of use (e.g., restricted vs. unrestricted public access). Public access is defined as “restricted” if public access can be controlled. Public access is defined as “unrestricted” if public access cannot be controlled. Unrestricted water uses have more stringent water quality regulations to limit public health risk and exposure to pollutants and microorganisms.

Stormwater level of effort categories include:

  • Minimal (pretreatment only) - Limited human exposure at point of use and limited exposure to pathogens upstream of point of use
  • Medium (pretreatment and disinfection, or pretreatment and treatment) - Limited human contact and controlled access at point of use
  • High (pretreatment, treatment and disinfection) - Uncontrolled access at point of use

The minimum recommendation for water reuse application is implementation of a pretreatment practice to reduce sediment, trash, debris and organic materials from entering the stormwater constructed management facility. The MPCA (2023) defines settling devices, screens and pretreatment vegetated filter strips as appropriate pretreatment devices.

Post-storage treatment processes include dissolved solids removal, chlorine residual removal and pH adjustments (MPCA, 2023). Disinfection processes are also recommended to kill, remove or deactivate pathogenic microorganisms in harvested water. These disinfection process recommendations include chlorination, UV radiation and ozonation (MPCA, 2023).

Minnesota does not provide water quality requirements specific to harvested stormwater. Rather, Minnesota refers to the existing criteria for rainwater catchment systems (Minn. Stat. § 4714.1601). The MPCA (2022) notes that, due to the wide range of harvested stormwater quality, the NWRI treatment recommendations based on risk of exposure should instead be followed for the design of stormwater harvesting system and the capture and use of stormwater.

Additional context and definitions

In Minnesota, a water-use permit is required for the appropriation or use of waters of the state, including stormwater, unless subject these exemptions:

  • Reuse of water for domestic purposes serving less than 25 persons for general residential purposes (Minn. Stat. § 116.103G.271).
  • Water collected is less than 10,000 gallons per day or one million gallons per year (Minn. Stat. § 116.103G.271).
  • Water Appropriation Permit – Stormwater Exemption: The use of stormwater collected from constructed management facilities for stormwater (Minn. Stat. § 116.103G.271).

Additional permits provide guidance on stormwater reuse, but none require or limit stormwater capture and use (MDH, 2018).

Water reuse for industrial applications specifications

None

Upcoming state law or policy

No upcoming stormwater reuse regulations were found for Minnesota.

References

Appropriation and use of waters, Minn. Stat. § 116.103G.271.

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

MDH. 2018. Water Reuse Report: Advancing Safe and Sustainable Water Reuse in Minnesota.

Minnesota Department of Natural Resources (MDNR). 2017. Water use permits: Storm Water Use and Appropriation is Permit Exempt.

Minnesota Pollution Control Agency (MPCA). 2023. Minnesota Stormwater Manual: Overview for stormwater and rainwater harvest and use/reuse.

MPCA. 2022. Minnesota Stormwater Manual: Water quality considerations for stormwater and rainwater harvest and use/reuse.

Disclaimers

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.

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Last updated on November 14, 2024