Presented below are water quality standards that are in effect for Clean Water Act purposes. EPA is posting these standards as a convenience to users and has made a reasonable effort to assure their accuracy. Additionally, EPA has made a reasonable effort to identify parts of the standards that are not approved, disapproved, or are otherwise not in effect for Clean Water Act purposes. July 10, 2020 In addition to the criteria provided in this document, EPA has approved site-specific standards for the following waters: Water Parameter(s) Rule Site Specific Standard EPA Approval Date Sauk River Flowage Eutrophication: 7050.0220 subp. 7 TP: < 90 µg/L 2/12/2020 Lakes including Total phosphorus Site-specific Chl-a: < 45 µg/L Horseshoe North, Chl-a modifications of Secchi depth: ≥ 0.8 m East Cedar Island, Secchi depth standards Koetter, Zumwalde, Great Northern, Krays, and Knaus/Park Sauk River Non- Eutrophication: 7050.0220 subp. 7 TP: < 55 µg/L 2/12/2020 flowage lakes Total phosphorus Site-specific Chl-a: < 32 µg/L including Chl-a modifications of Secchi depth: ≥ 1.4 m Horseshoe West, Secchi depth standards Horseshoe South, Cedar Island, and Bolfing Lower Minnesota Selenium 7050.0222 subp. 4 Selenium: 11 µg/L 10/21/2019 River Main Channel, Site-specific starting at modifications of approximately River standards Mile 6, at the discharge for the Seneca Wastewater Treatment Plant, and ending at the confluence of the Minnesota River with the Mississippi River Lower Minnesota Selenium 7050.0222 subp. 4 Selenium: 5.7 µg/L 10/21/2019 River Oxbow and Site-specific Floodplain Lakes modifications of (19-0078-00 and standards 27-0002-00) Lake Zumbro, Eutrophication: 7050.0220 subp. 7 TP: < 105 µg/L 8/28/2018 Segment 2 Total phosphorus Site-specific Chl-a: < 48 µg/L Chl-a modifications of Secchi depth: ≥ 1.1 m Secchi depth standards Lake Zumbro, Eutrophication: 7050.0220 subp. 7 TP: < 75 µg/L 8/28/2018 Segment 3 Total phosphorus Site-specific Chl-a: < 40 µg/L Chl-a modifications of Secchi depth: ≥ 1.4 m Secchi depth standards Spring Lake Eutrophication: 7050.0222 subp.4 TP: 60 µg/L 7/19/2016 (70-0054-00) Total phosphorus Eutrophication Chl-a: 20 µg/L Chl-a standards Secchi disk Secchi disk transparency transparency: 1.4 m Lake Winona Eutrophication: 7050.0222 subp.4 TP: 75 µg/L 6/12/2014 (21-0081-00) Total phosphorus Eutrophication Chl-a: 20 µg/L Chl-a standards Secchi disk Secchi disk transparency transparency: 1.0 m Lake Nokomis Eutrophication: 7050.0222 subp.4 TP: < 50 µg/L 9/9/2013 (27-0019-00) Total phosphorus Eutrophication Chl-a: < 20 µg/L Chl-a standards Secchi disk Secchi disk transparency transparency: 1.4 m Lake Hiawatha Eutrophication: 7050.0222 subp.4 TP: < 50 µg/L 7/24/2013 (27-0018-00) Total phosphorus Eutrophication Chl-a: 14 µg/L Chl-a standards Secchi disk Secchi disk transparency transparency: 1.4 m Lake Byllesby Eutrophication: 7050.0222 subp.4 TP: < 90 µg/L 8/26/2011 (lower two-thirds of Total phosphorus Eutrophication Chl-a: < 30 µg/L 19-0006-00, the Chl-a standards Secchi disk combined Secchi disk transparency transparency: > 0.8 m transitional and near-dam The standards apply for segments) flows that range from 180 cubic feet per second (for summer 122 day, one in ten year recurrence, 10th percentile flow) to 940 cubic feet per second (for 80th percentile flow) as measured at the combined transitional and near dam segments. The flow ranges correspond to a residence time of 8 to 10 days. French River at Temperature 7050.0222 subp.2 November–April: Not to 7/8/2004 SW003 (T.51N, exceed 50 degrees F as R.12W, S.17, SW a monthly average. 1/4) station located between County May–October: Not to Highway 61 and exceed the monthly Lake Superior. average temperature at SW001 (located 0.04 Covers only the miles upstream from area near the SW003 at T.51N, mouth/ confluence R.12W, S.17, SW 1/4) with Lake Superior (located on 04010102-698). Red River of the Total ammonia nitrogen 7050.0222 subp.3 Ammonia, total in mg 6/20/2000 North, from just N/L downstream of Chronic Standard 12th Ave N bridge (CStox) in Fargo to the -Thirty Day Standard: confluence with the The concentration of Buffalo River total ammonia (09020104-502 & nitrogen, in mg N/L, in 09020104-511) any thirty day period cannot exceed the applicable CStox values (as derived below*), more than once every three years on average; AND -Four Day Standard: The average concentration of the four days of highest ammonia, in mg N/L concentrations within the 30 days applied to the equation must not exceed 2.5 times the value of the applicable CStox. The CStox varies depending on the applicable months for each equation and also on pH and temperature. Crow River, South Copper 7050.0222 subp.4 Copper: < 67.3 µg/L, 1/8/1996 Fork at Hutchinson based on a hardness of WWTP outfall 400 mg/L T.116, R29W, s.7 NE1/4 (located on 07010205-510, NPDES permit MN0055832). Unnamed wetland Copper 7050.0222 subp.4 Copper: < 23.2 µg/L, 4/19/1994 adjacent to Lake based on a hardness of Winona (21-0081) 400 mg/L at ALASD outfall T.128, R38W, S.25 NW1/4 *For March through September: CStox =( 0.0577/(1+〖10〗^(7.688-pH) )+ 2.487/(1+ 〖10〗^(pH-7.688) ) ) x MIN(2.85,1.45 x〖10〗^0.028(25-T)) Where: pH means ambient water pH; and MIN means multiply by the minimum value of either 2.85 or 1.45 x〖10〗^(0.028(25- T)), where T means the ambient water Temperature in degrees Celsius (C). In this equation, 2.85 is used when T is less than or equal to 14° C. *For October through February CStox =( 0.0577/(1+〖10〗^(7.688-pH) )+ 2.487/(1+ 〖10〗^(pH-7.688) ) ) x MIN (4.63,1.45 x〖10〗^0.028(25-T) ) Where: MIN means multiply by the minimum value of either 4.63 or 1.45 x〖10〗^(0.028(25-T)). In this equation, 4.63 is used when T is less than or equal to 7° C. Other variables as previously defined. 1​ MINNESOTA RULES​ CHAPTER 7050​ MINNESOTA POLLUTION CONTROL AGENCY​ WATERS OF THE STATE​ WATER QUALITY STANDARDS FOR PROTECTION OF​ WATERS OF THE STATE​ 7050.0110​ SCOPE.​ 7050.0130​ GENERAL DEFINITIONS.​ 7050.0140​ USE CLASSIFICATIONS FOR WATERS OF THE STATE.​ 7050.0150​ DETERMINATION OF WATER QUALITY, BIOLOGICAL AND PHYSICAL CONDITIONS, AND​ COMPLIANCE WITH STANDARDS.​ 7050.0155​ PROTECTION OF DOWNSTREAM USES.​ 7050.0170​ NATURAL WATER QUALITY.​ 7050.0186​ WETLAND STANDARDS AND MITIGATION.​ 7050.0190​ VARIANCE FROM STANDARDS.​ 7050.0210​ GENERAL STANDARDS FOR WATERS OF THE STATE.​ 7050.0217​ OBJECTIVES FOR PROTECTION OF SURFACE WATERS FROM TOXIC POLLUTANTS.​ 7050.0218​ FOR TOXIC POLLUTANTS: DEFINITIONS AND METHODS FOR DETERMINATION OF HUMAN​ HEALTH-BASED NUMERIC STANDARDS AND SITE-SPECIFIC NUMERIC CRITERIA FOR​ AQUATIC LIFE, HUMAN HEALTH, AND FISH-EATING WILDLIFE.​ 7050.0219​ HUMAN HEALTH-BASED CRITERIA AND STANDARDS.​ 7050.0220​ SPECIFIC WATER QUALITY STANDARDS BY ASSOCIATED USE CLASSES.​ 7050.0221​ SPECIFIC WATER QUALITY STANDARDS FOR CLASS 1 WATERS OF THE STATE; DOMESTIC​ CONSUMPTION.​ 7050.0222​ SPECIFIC WATER QUALITY STANDARDS FOR CLASS 2 WATERS OF THE STATE; AQUATIC​ LIFE AND RECREATION.​ 7050.0223​ SPECIFIC WATER QUALITY STANDARDS FOR CLASS 3 WATERS OF THE STATE;​ INDUSTRIAL CONSUMPTION.​ 7050.0224​ SPECIFIC WATER QUALITY STANDARDS FOR CLASS 4 WATERS OF THE STATE;​ AGRICULTURE AND WILDLIFE.​ 7050.0225​ SPECIFIC WATER QUALITY STANDARDS FOR CLASS 5 WATERS OF THE STATE; AESTHETIC​ ENJOYMENT AND NAVIGATION.​ 7050.0226​ SPECIFIC WATER QUALITY STANDARDS FOR CLASS 6 WATERS OF THE STATE; OTHER​ USES.​ 7050.0227​ SPECIFIC WATER QUALITY STANDARDS FOR CLASS 7 WATERS OF THE STATE; LIMITED​ RESOURCE VALUE WATERS.​ 7050.0250​ ANTIDEGRADATION PURPOSE.​ 7050.0255​ DEFINITIONS.​ Copyright © 2017 by the Revisor of Statutes, State of Minnesota. All Rights Reserved.​ 7050.0100​ MINNESOTA RULES​ 2​ 7050.0260​ DETERMINING EXISTING WATER QUALITY.​ 7050.0265​ ANTIDEGRADATION STANDARDS WHEN CHANGES IN EXISTING WATER QUALITY ARE​ REASONABLY QUANTIFIABLE.​ 7050.0270​ ANTIDEGRADATION STANDARDS WHEN CHANGES IN EXISTING WATER QUALITY ARE​ NOT REASONABLY QUANTIFIABLE.​ 7050.0275​ EXEMPTIONS FROM PROCEDURES.​ 7050.0280​ PROCEDURES FOR INDIVIDUAL NPDES WASTEWATER PERMITS AND INDIVIDUAL NPDES​ STORM WATER PERMITS FOR INDUSTRIAL AND CONSTRUCTION ACTIVITIES.​ 7050.0285​ PROCEDURES FOR SECTION 401 CERTIFICATIONS OF INDIVIDUAL FEDERAL LICENSES​ AND PERMITS.​ 7050.0290​ PROCEDURES FOR INDIVIDUAL NPDES PERMITS FOR MUNICIPAL SEPARATE STORM​ SEWER SYSTEMS.​ 7050.0295​ PROCEDURES FOR GENERAL NPDES PERMITS.​ 7050.0305​ PROCEDURES FOR SECTION 401 CERTIFICATIONS OF GENERAL SECTION 404 PERMITS.​ 7050.0315​ PROCEDURES FOR SECTION 401 CERTIFICATIONS OF GENERAL FEDERAL LICENSES AND​ PERMITS OTHER THAN SECTION 404 PERMITS.​ 7050.0325​ PROCEDURES FOR MULTIPLE CONTROL DOCUMENTS.​ 7050.0335​ DESIGNATED OUTSTANDING RESOURCE VALUE WATERS.​ CLASSIFICATIONS​ 7050.0400​ BENEFICIAL USE CLASSIFICATIONS FOR SURFACE WATERS; SCOPE.​ 7050.0405​ PETITION BY OUTSIDE PARTY TO CONSIDER ATTAINABILITY OF USE.​ 7050.0410​ LISTED WATERS.​ 7050.0420​ TROUT WATERS.​ 7050.0425​ UNLISTED WETLANDS.​ 7050.0430​ UNLISTED WATERS.​ 7050.0440​ OTHER CLASSIFICATIONS SUPERSEDED.​ 7050.0450​ MULTICLASSIFICATIONS.​ 7050.0460​ WATERS SPECIFICALLY CLASSIFIED; EXPLANATION OF LISTINGS IN PART 7050.0470.​ 7050.0466​ MAP: MAJOR SURFACE WATER DRAINAGE BASINS.​ 7050.0468​ MAP: MINNESOTA ECOREGIONS.​ 7050.0469​ MAP: MINNESOTA'S MAJOR WATERSHEDS.​ 7050.0470​ CLASSIFICATIONS FOR SURFACE WATERS IN MAJOR DRAINAGE BASINS.​ 7050.0100 [Repealed, 9 SR 913]​ Published Electronically: April 1, 2008​ Copyright © 2017 by the Revisor of Statutes, State of Minnesota. All Rights Reserved.​ 3​ MINNESOTA RULES​ 7050.0130​ WATER QUALITY STANDARDS FOR PROTECTION OF​ WATERS OF THE STATE​ 7050.0110 SCOPE.​ Parts 7050.0130 to 7050.0227 apply to all waters of the state, both surface and underground.​ This chapter includes a classification system of beneficial uses applicable to waters of the state,​ narrative and numeric water quality standards that protect specific beneficial uses, antidegradation​ provisions, and other provisions to protect the physical, chemical, and biological integrity of waters​ of the state.