Minnesota Legislature
Office of the Revisor of Statutes
Minnesota Administrative Rules
7050.0223 SPECIFIC WATER QUALITY STANDARDS FOR CLASS 3 WATERS OF THE STATE; INDUSTRIAL CONSUMPTION.
Subpart 1.
General.
The numeric and narrative water quality standards in this part prescribe the qualities or properties of the waters of the state that are necessary for the industrial consumption designated public uses and benefits. If the standards in this part are exceeded in waters of the state that have the class 3 designation, it is considered indicative of a polluted condition which is actually or potentially deleterious, harmful, detrimental, or injurious with respect to the designated uses.
Subp. 2.
Class 3A waters; industrial consumption.
The quality of class 3A waters of the state shall be such as to permit their use without chemical treatment, except softening for groundwater, for most industrial purposes, except food processing and related uses, for which a high quality of water is required. The following standards shall not be exceeded in the waters of the state:
| Substance, Characteristic, or Pollutant | Class 3A Standard |
| Chlorides (Cl) | 50 mg/L |
| Hardness, Ca + Mg as CaCO3 | 50 mg/L |
| pH, minimum value | 6.5 |
| pH, maximum value | 8.5 |
Subp. 3.
Class 3B waters.
The quality of class 3B waters of the state shall be such as to permit their use for general industrial purposes, except for food processing, with only a moderate degree of treatment. The following standards shall not be exceeded in the waters of the state:
| Substance, Characteristic, or Pollutant | Class 3B Standard |
| Chlorides (Cl) | 100 mg/L |
| Hardness, Ca + Mg as CaCO3 | 250 mg/L |
| pH, minimum value | 6.0 |
| pH, maximum value | 9.0 |
Subp. 4.
Class 3C waters.
The quality of class 3C waters of the state shall be such as to permit their use for industrial cooling and materials transport without a high degree of treatment being necessary to avoid severe fouling, corrosion, scaling, or other unsatisfactory conditions. The following standards shall not be exceeded in the waters of the state:
| Substance, Characteristic, or Pollutant | Class 3C Standard |
| Chlorides (Cl) | 250 mg/L |
| Hardness, Ca + Mg as CaCO3 | 500 mg/L |
| pH, minimum value | 6.0 |
| pH, maximum value | 9.0 |
Subp. 5.
Class 3D waters; wetlands.
The quality of class 3D wetlands shall be such as to permit their use for general industrial purposes, except for food processing, with only a moderate degree of treatment. The following standards apply:
| Substance, Characteristic, or Pollutant | Class 3D Standard |
| Chlorides (Cl) | Maintain background |
| Hardness, Ca + Mg as CaCO3 | Maintain background |
| pH | Maintain background |
For the purposes of this subpart, "maintain background" means the concentration of the water quality substance, characteristic, or pollutant shall not deviate from the range of natural background concentrations or conditions such that there is a potential significant adverse impact to the designated uses.
Subp. 6.
Additional standards.
Additional selective limits may be imposed for any specific waters of the state as needed.
In addition to the standards in subparts 2 to 5, no sewage, industrial waste, or other wastes from point or nonpoint sources, treated or untreated, shall be discharged into or permitted by any person to gain access to any waters of the state classified for industrial purposes so as to cause any material impairment of their use as a source of industrial water supply.
History:
18 SR 2195; 32 SR 1699
Published Electronically:
December 9, 2016
Official Publication of the State of Minnesota
Revisor of Statutes