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A water quality variance is a temporary change in a state's water quality standard for a specific pollutant and its relevant criteria, allowing deviation from meeting a water quality-based effluent limit for a particular discharger. Federal and state regulations afford the flexibility to adopt a variance in some situations. For example, a discharger may be uncertain if it can ultimately meet permit limits and either wants to more fully assess its ability before investing in expensive controls, or the discharger anticipates less-expensive control technology becoming available in the near term. In these and other situations, variances are appropriate if they meet the criteria and provisions set by U.S. Environmental Protection Agency (EPA) and MPCA. 

The EPA allows states to adopt variance provisions, but has ultimate approval over variances proposed by MPCA. As the agency delegated to implement the Clean Water Act, MPCA may grant variances through the National Pollution Discharge Elimination System/State Disposal System permit program. Because of this collaboration, MPCA must assess a variance using the same conditions and criteria that EPA uses. This will ensure a smooth processing of variance requests.

Guidance documents

Resources to help determine if a water quality variance is an allowable option for your permitted facility.

Chloride

Visit the Water permit holders and chloride page for information on chloride standard variances for wastewater treatment facilities.

Sulfate

Proposed variances

Kerkhoven Wastewater Treatment Facility

  • Permit ID: MN0020583
  • Pollutant (or restriction) for which variance is proposed: Chloride
  • Rule citation: 7050.0222, subp. 4, Total Chloride
  • Proposed variance term: 15 years
  • Receiving water: County Ditch 61 in the Chippewa River Watershed
  • Public Comment Period: May 20, 2024, through July 19, 2024

To review and comment on the proposed permit and variance, visit the Public comments web page.

Facilities requesting chloride variances must demonstrate that they are achieving the “highest attainable condition,” which prevents worsening pollution while a path to chloride reduction is identified and followed. The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

Public meetings are required for water quality standard variances. An online public meeting is planned for July 9, 2024, for the City of Kerkhoven’s variance request. 

Nerstrand Wastewater Treatment Facility

  • Permit ID: MN0065668
  • Pollutant (or restriction) for which variance is proposed: Chloride
  • Rule citation: 7050.0222, subp. 4, Total Chloride
  • Proposed variance term: 15 years
  • Receiving water: Unnamed ditch in the Cannon River Watershed
  • Public comment period: April 11 through June 10, 2024

To review and comment on the proposed permit and variance, visit the Public comments web page.

Facilities requesting chloride variances must demonstrate that they are achieving the “highest attainable condition,” which prevents worsening pollution while a path to chloride reduction is identified and followed. The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

Public meetings are required for water quality standard variances. An online public meeting is planned for May 28, 2024, for the City of Nerstrand's variance request.

New Richland Wastewater Treatment Facility

  • Permit ID: MN0021032
  • Pollutant (or restriction) for which variance is proposed: Chloride
  • Rule citation: 7050.0222, subp. 4, Total Chloride
  • Proposed variance term: 15 years
  • Receiving water: Unnamed ditch in the Le Sueur River Watershed
  • Public comment period: March 8 through May 7, 2024

To review and comment on the proposed permit and variance, visit the Public comments web page.

Facilities requesting chloride variances must demonstrate that they are achieving the “highest attainable condition,” which prevents worsening pollution while a path to chloride reduction is identified and followed. The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

Public meetings are required for water quality standard variances. An online public meeting was held on April 23, 2024, for the City of New Richland’s variance request.

Lonsdale Wastewater Treatment Facility

  • Permit ID: MN0031241
  • Pollutant (or restriction) for which variance is proposed: Chloride
  • Rule citation: 7050.0222, subp. 4, Total Chloride
  • Proposed variance term: 15 years
  • Receiving water: Unnamed ditch in the Cannon River Watershed
  • Public comment period: March 1 through April 30, 2024

To review and comment on the proposed permit and variance, visit the Public comments web page.

Facilities requesting chloride variances must demonstrate that they are achieving the “highest attainable condition,” which prevents worsening pollution while a path to chloride reduction is identified and followed. The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

Public meetings are required for water quality standard variances. An online public meeting was held April 25, 2024, for the City of Lonsdale's variance request.

Grand Marais Wastewater Treatment Facility

  • Permit ID: MN0020010
  • Pollutant (or restriction) for which variance is proposed: Mercury
  • Rule citation: 7052.0100, subp. 2, Total Mercury
  • Proposed variance term: 5 years
  • Receiving water: Lake Superior
  • Public comment period: March 22 through May 21, 2024

To review and comment on the proposed permit and variance, visit the Public comments web page.

Facilities requesting mercury variances must demonstrate that they are achieving the “highest attainable condition,” which prevents worsening pollution while a path to mercury reduction is identified and followed. The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific mercury action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created mercury pollutant minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

Public meetings are required for water quality standard variances. A hybrid public meeting was held on May 8, 2024, for the City of Grand Marais's variance request.

Tri-City Wastewater Treatment Systems Board Treatment Facility

  • Permit ID: MN0025224
  • Pollutant (or restriction) for which variance is proposed: Chloride
  • Rule citation: 7050.0222, subp. 4, Total Chloride
  • Proposed variance term: 15 years
  • Receiving water: County Ditch 87 in the Le Sueur River Watershed
  • Public comment period: April 1 through May 31, 2024

To review and comment on the proposed permit and variance, visit the Public comments web page.

Facilities requesting chloride variances must demonstrate that they are achieving the “highest attainable condition,” which prevents worsening pollution while a path to chloride reduction is identified and followed. The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

Public meetings are required for water quality standard variances. An online public meeting was held May 21, 2024, for the Tri-City Wastewater Treatment Systems Board's variance request.

Active variances

Details on variances in National Pollutant Discharge Elimination System/State Disposal System permits issued by the MPCA. This list is updated annually by October 1.

Dawson Wastewater Treatment Facility

Permit ID: MN0021881
Pollutant (or restriction) for which variance is granted: Chloride
Rule citation: 7050.0222, subp. 4, Total Chloride
Receiving water: County Judicial Ditch 4 (Lac qui Parle River Watershed)
Date approved: April 8, 2024; permit reissued May 1, 2024
Restrictions in lieu of pollutant limit/restriction: The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

Altura Wastewater Treatment Facility

Permit ID: MN0021831
Pollutant (or restriction) for which variance is granted: Chloride
Rule citation: 7050.0222, subp. 4, Total Chloride
Receiving water: Unnamed dry run in the Mississippi River – Winona Watershed
Date approved: April 3, 2024; permit reissued April 12, 2024
Restrictions in lieu of pollutant limit/restriction: The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

Marshall Wastewater Treatment Facility

Permit ID: MN0022179
Pollutant (or restriction) for which variance is granted: Chloride
Rule citation: 7050.0222, subp. 4, Total Chloride
Receiving water: Redwood River (Redwood River Watershed)
Date approved: Feb. 1, 2024; permit reissued March 1, 2024
Restrictions in lieu of pollutant limit/restriction: The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

City of Saint James Wastewater Treatment Plant

Permit ID: MN0024759
Pollutant (or restriction) for which variance is granted: Chloride
Rule citation: 7050.0222, subp. 4, Total Chloride
Receiving water: Saint James Creek (Watonwan River Watershed)
Date approved: Oct. 24, 2023; permit reissued Nov. 1, 2023
Restrictions in lieu of pollutant limit/restriction: The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance. This variance was approved for a 15-year term, with re-evaluations every five years.

Lewiston Wastewater Treatment Plant

Permit ID: MN0023965
Pollutant (or restriction) for which variance is granted: Chloride
Rule citation: 7050.0222, subp. 4, Total Chloride
Receiving water: This facility discharges to a dry run, the headwater of Rush Creek (Root River Watershed)
Date approved: July 24, 2023; permit reissued Aug. 4, 2023
Restrictions in lieu of pollutant limit/restriction: The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

Lester Prairie Wastewater Treatment Plant

Permit ID: MN0023957
Pollutant (or restriction) for which variance is granted: Chloride
Rule citation: 7050.0222, subp. 4, Total Chloride
Receiving water: South Fork Crow River (South Fork Crow River Watershed)
Date approved: June 23, 2023; permit reissued June 30, 2023
Restrictions in lieu of pollutant limit/restriction: The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

Western Lake Superior Sanitary District (WLSSD)

Permit ID: MN0049786
Pollutant (or restriction) for which variance is granted: fecal coliform (year-round disinfection) and mercury
Rule citation: 7053.0215 subp. 1 and 7052.0100 subp. 5, respectively (related to pollutants above)
Receiving water: St. Louis Bay (St. Louis River) and Superior Bay to Lake Superior
Date approved: May 19, 2023 (mercury variance)
Permit reissuance: May 23, 2023 (includes variances for fecal coliform and year-round disinfection)
Restrictions in lieu of pollutant limit/restriction: Interim mercury effluent limits lower than the previous NPDES/SDS permit; additional mercury monitoring; further investigation of potential mercury removal technologies. Compliance with a fecal coliform limit from April 1 through October 31 of each year; monitoring the SD001 station year-round and requires intervention disinfection limits if monitoring at two drinking water intakes exceed a specified numeric level; evaluate alternative disinfection options.

Waseca Wastewater Treatment Plant

Permit ID: MN0020796
Pollutant (or restriction) for which variance is granted: Chloride
Rule citation: 7050.0222, subp. 4, Total Chloride
Receiving water: Unnamed creek (Le Sueur River Watershed)
Date approved: March 30, 2023; permit reissued April 3, 2023
Restrictions in lieu of pollutant limit/restriction: The MPCA has determined the highest attainable condition of the receiving water is most appropriately achieved through combining (1) a facility-specific interim effluent limit, (2) a facility-specific chloride action tree, to be submitted with the variance application, which identifies actions to be taken immediately upon permit issuance, and (3) a permittee-created chloride Investigation and minimization plan, per 40 CFR 131.14(b)(1)(iii). The plan is due within 180 days of permit reissuance.

City of Albert Lea Wastewater Treatment Plant

Permit ID: MN0041092
Pollutant (or restriction) for which variance is granted: Chloride
Rule citation: 7050.0222, subp. 4, Total Chloride
Receiving water: Shell Rock River (Shell Rock River Watershed)
Date approved: Dec. 17, 2021; permit issued Feb. 1, 2022
Restrictions in lieu of pollutant limit/restriction: Chloride Investigation & Minimization Plan due 180 days after issuance that includes iterative process to identify sources and incorporate source reduction measures. Alternate limits apply throughout the variance term (8 years) to be updated every 5 years based on re-evaluation (40 CFR 131.14(b)(1)(iii)).

Glacial Lakes Sanitary Sewer and Water District

Permit ID: MN0052752
Pollutant (or restriction) for which variance is granted: Chloride
Rule citation: 7050.0222, subp. 4, Total Chloride
Receiving water: Middle Fork of the Crow River (North Fork Crow River Watershed)
Date approved: Dec. 14, 2021; permit issued Jan. 4, 2022
Restrictions in lieu of pollutant limit/restriction: Chloride Investigation & Minimization Plan due 180 days after issuance that includes iterative process to identify sources and incorporate source reduction measures. Alternate limits apply throughout the variance term (8 years) to be updated every 5 years based on re-evaluation (40 CFR 131.14(b)(1)(iii)).

City of Sherburn Wastewater Treatment Plant

Permit ID: MN0024872
Pollutant (or restriction) for which variance is granted: Total hardness (Ca + Mg as CaCO3), Specific Conductance, Total Dissolved Solids, Bicarbonates
Rule citation: 7050.0223 and 7050.0224
Receiving water: Martin County Ditch 11 (East Fork Des Moines River Watershed)
Date approved: May 27, 2021; permit issued June 30, 2021
Restrictions in lieu of pollutant limit/restriction: Within 180 days after permit reissuance, the Permittee shall submit an updated Salty Discharge Management Plan which details actions the Permittee will take to identify sources of salty parameter loading to the WWTP and to the receiving water. Alternate limits apply throughout the variance term (5 years) and may be revisited during permit reissuance (40 CFR 131.14(b)(1)(iii)).

City of Worthington Wastewater Treatment Plant

Permit ID: MN0031186
Pollutant (or restriction) for which variance is granted: Total Chloride
Rule citation: 7050.0222, subp. 2
Receiving water: Okabena Creek (Des Moines River – Headwaters Watershed)
Date approved: May 4, 2021; permit issued May 7, 2021
Restrictions in lieu of pollutant limit/restriction: Plan due 180 days after issuance that includes iterative process to reduce sources identified in the variance request form, identify other sources, and incorporate source reduction measures. Alternate limits apply throughout the variance term (15 years) to be updated every 5 years based on re-evaluation (40 CFR 131.14(b)(1)(iii)).

Southern Minnesota Beet Sugar – Renville

Permit ID: MN0040665
Pollutant (or restriction) for which variance is granted: bicarbonates, hardness, total dissolved solids, total salinity, and specific conductance
Rule citation: 7050.0223, 7050.0224, 7050.0210
Receiving water: County Ditch 45
Date approved: Dec. 16, 2020; permit issued Dec. 18, 2020.
Restrictions in lieu of pollutant limit/restriction: Alternate effluent limitation for specific conductance and continued reductions in the discharge through implementation of a dissolved mineral reduction program.

Alexandria Lake Area Sanitary District (ALASD)

Permit ID: MN0040738
Pollutant (or restriction) for which variance is granted: Chloride
Rule citation: 7050.0222, subp. 4, Total Chloride
Receiving water: Lake Winona (Mississippi River – Winona Watershed)
Date approved:  Oct. 28, 2020; permit issued Nov. 15, 2020
Restrictions in lieu of pollutant limit/restriction: Chloride Investigation & Minimization Plan due 180 days after issuance that includes iterative process to identify sources and incorporate source reduction measures. Alternate limits apply throughout the variance term (8 years) to be updated every 5 years based on re-evaluation (40 CFR 131.14(b)(1)(iii)).

Avon Wastewater Treatment Plant

Permit ID: MN0047325
Pollutant (or restriction) for which variance is granted: Chloride
Rule citation: 7050.0222, subp. 4, Total Chloride
Receiving water: Spunk Creek (Mississippi River – Sartell Watershed)
Date approved: Feb. 25, 2020; permit issued March 15, 2020 (limits and monitoring effective April 1, 2020)
Restrictions in lieu of pollutant limit/restriction: Chloride Investigation & Minimization Plan due 180 days after issuance that includes iterative process to identify sources and incorporate source reduction measures. Alternate limits apply throughout the variance term (15 years) to be updated every 5 years based on re-evaluation (40 CFR 131.14(b)(1)(iii)).

Cliffs Erie – Dunka Mining

Permit ID: MN0042579
Pollutant (or restriction) for which variance is granted: Total Hardness (Ca + Mg as CaCO3), Specific Conductance, Total Dissolved Solids, Bicarbonates
Rule citation: 7050.0212 subp. 6 and 7050.0222 subp. 7B
Receiving water: Unnamed creek, headwaters to Bob Bay (Birch Lake)
Date approved: July 25, 2000
Restrictions in lieu of pollutant limit/restriction: Alternate ‘additive toxicity’ limit for Outfalls SD008 and SD009 applicable during cold weather months. Chronic WET 3x/yr, biomonitoring and fish monitoring, and treatment optimization study. In 2008 application for permit reissuance, Permittee requested continuation of the variance. In response, MPCA staff indicated they would likely not be able to support a renewal of the variance. Since the 2008 application, MPCA entered into a Consent Decree with Cliffs Erie to address alleged noncompliance. Actions taken by Cliffs Erie in response to the Consent Decree has resulted in improvements in effluent quality such that the requested variance will no longer be needed (i.e., the request will not be processed as part of the future permit reissuance).

United Taconite LLC - Thunderbird Mine

Permit ID: MN0044946
Pollutant (or restriction) for which variance is granted: pH
Rule citation: 7050.0224, Subp. 2; 7050.0227 Subp. 2
Receiving water: SD007 - Stream 4 to Manganika Creek. SD009 - Manganika Creek
Date approved: June 12, 1999
Restrictions in lieu of pollutant limit/restriction: Alternate pH limit of 9.3 due to naturally high pH in groundwater (Outfalls SD007 and SD009). Based on application (deemed complete 11/13/2009), MPCA has no plans to renew this variance.