NR 270.003(2)(a)
(a) The facility is designed, constructed, and maintained to contain the maximum volume of wastewater which would be generated by the facility during a 24-hour period without an increase in volume from precipitation and the maximum volume of wastewater resulting from a 10-year, 24-hour precipitation event or treat the maximum flow associated with these volumes. In computing the maximum volume of wastewater which would result from a 10-year, 24-hour precipitation event, the facility shall include the volume which would result from all areas contributing runoff to the individual treatment facility, i.e., all runoff that is not diverted from the active mining area and runoff which is not diverted from the mill area.
NR 270.003(2)(b)
(b) The facility takes all reasonable steps to maintain treatment of the wastewater and minimize the amount of overflow.
NR 270.003(2)(c)
(c) The facility complies with the notification requirements of
40 CFR 122.41 (m) and (n). The storm exemption is designed to provide an affirmative defense to an enforcement action. Therefore, the operator has the burden of demonstrating to the appropriate authority that the conditions have been met.
NR 270.003(3)
(3) Storm exemption for facilities not permitted to discharge. If, as a result of precipitation (rainfall or snowmelt), a source which is not permitted to discharge under this chapter, has an overflow or discharge which violates the limitations of this chapter, the source may qualify for an exemption from such limitations with respect to such discharge if the following conditions are met:
NR 270.003(3)(a)
(a) The facility is designed, constructed, and maintained to contain the maximum volume of wastewater stored and contained by the facility during normal operating conditions without an increase in volume from precipitation and the maximum volume of wastewater resulting from a 10-year, 24-hour precipitation event. In computing the maximum volume of wastewater which would result from a 10-year, 24-hour precipitation event, the facility shall include the volume which would result from all areas contributing runoff to the individual treatment facility, i.e., all runoff that is not diverted from the area or process subject to zero discharge, and other runoff that is allowed to commingle with the influent to the treatment system.
NR 270.003(3)(b)
(b) The facility takes all reasonable steps to minimize the overflow or excess discharge.
NR 270.003(3)(c)
(c) The facility complies with the notification requirements of
40 CFR 122.41 (m) and (n). The storm exemption is designed to provide an affirmative defense to an enforcement action. Therefore, the operator has the burden of demonstrating to the appropriate authority that the conditions have been met.
NR 270.003(4)(a)
(a) Where the application of neutralization and sedimentation technology to comply with relevant metal limitations results in an inability to comply with the pH range of 6.0 to 9.0, the permit issuer may allow the pH level in the final effluent to slightly exceed 9.0 so that the copper, lead, zinc, mercury and cadmium limitations will be achieved.
NR 270.003(4)(b)
(b) In the case of a discharge into natural receiving waters for which the pH, if unaltered by human activities, is or would be less than 6.0 and approved water quality standards authorize such lower pH, the pH limitations for the discharge may be adjusted downward to the pH water quality criterion for the receiving waters provided the other effluent limitations for the discharge are met. In no case may a pH limitation below 5.0 be permitted.
NR 270.003(5)
(5) Groundwater infiltration provision. In the event a new source subject to a no discharge requirement can demonstrate that groundwater infiltration contributes a substantial amount of water to the tailing impoundment or wastewater holding facility, the department may allow the discharge of a volume of water equivalent to the amount of groundwater infiltration. This discharge shall be subject to the limitations for mine drainage applicable to the new source subcategory.
NR 270.003 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.01
NR 270.01 Applicability: description of the iron ore subcategory. The provisions of this subcategory are applicable to discharges from:
NR 270.01(1)
(1) Mines operated to obtain iron ore, regardless of the type of ore or its mode of occurrence; and
NR 270.01(2)
(2) Mills beneficiating iron ores by physical (magnetic and nonmagnetic) or chemical separation, or both.
NR 270.01 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.012
NR 270.012 Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT). Except as provided in ss.
NR 270.0015,
270.002 and
270.003 and
40 CFR 125.30 - 125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable after application of the best practicable control technology currently available (BPT):
NR 270.012(1)
(1) The concentration of pollutants discharged in mine drainage from mines operated to obtain iron ore may not exceed:
-
See PDF for table 
NR 270.012(2)
(2) The concentration of pollutants discharged from mills that employ physical (magnetic and nonmagnetic) or chemical methods, or both, to beneficiate iron ore may not exceed:
-
See PDF for table NR 270.012 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.013
NR 270.013 Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). Except as provided in ss.
NR 270.0015,
270.002 and
270.003 and
40 CFR 125.30-125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT):
NR 270.013(1)
(1) The concentration of pollutants discharged in mine drainage from mines operated to obtain iron ore may not exceed:
-
See PDF for table NR 270.013(2)
(2) The concentration of pollutants discharged from mills that employ physical (magnetic and nonmagnetic) or chemical methods, or both, to beneficiate iron ore may not exceed:
-
See PDF for table NR 270.013 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.014
NR 270.014 New source performance standards (NSPS). Except as provided in ss.
NR 270.0015,
270.002 and
270.003, any new source subject to this subcategory shall achieve the following NSPS representing the degree of effluent reduction attainable by the application of the best available demonstrated technology (BADT):
NR 270.014(1)
(1) The concentration of pollutants discharged in mine drainage from mines operated to obtain iron ore may not exceed:
-
See PDF for table NR 270.014(2)
(2) The concentration of pollutants discharged from mills that employ physical (magnetic and nonmagnetic) or chemical methods, or both, to beneficiate iron ore may not exceed:
-
See PDF for table NR 270.014 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86
NR 270.02
NR 270.02 Applicability: description of the aluminum ore subcategory. The provisions of this subcategory are applicable to discharges from facilities engaged in the mining of bauxite as an aluminum ore.
NR 270.02 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.022
NR 270.022 Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT). Except as provided in ss.
NR 270.0015,
270.002 and
270.003 and
40 CFR 125.30 - 125.32, any existing source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT), The concentration of pollutants discharged in mine drainage from mines producing bauxite ores may not exceed:
-
See PDF for table NR 270.022 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86
NR 270.023
NR 270.023 Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). Except as provided in ss.
NR 270.0015,
270.002 and
270.003 and
40 CFR 125.30 - 125.32, any existing point source subject to this subcategory shall achieve the following limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). The concentration of pollutants discharged in mine drainage from mines producing bauxite ores may not exceed:
-
See PDF for table NR 270.023 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.024
NR 270.024 New source performance standards (NSPS). Except as provided in ss.
NR 270.0015,
270.002 and
270.003, any new source subject to this subcategory shall achieve the following NSPS representing the degree of effluent reduction attainable by the application of the best available demonstrated technology (BADT). The concentration of pollutants discharged in mine drainage from mines producing bauxite ores may not exceed:
-
See PDF for table NR 270.024 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.03
NR 270.03 Applicability; description of the uranium, radium and vanadium ores subcategory. The provisions of this subcategory are applicable to discharges from:
NR 270.03(1)
(1) Mines either open-pit or underground, from which uranium, radium and vanadium ores are produced; and
NR 270.03(2)
(2) Mills using the acid leach, alkaline leach, or combined acid and alkaline leach process for extraction of uranium, radium and vanadium. Only vanadium byproduct production from uranium ores is covered under this subcategory.
NR 270.03 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.032
NR 270.032 Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT). Except as provided in ss.
NR 270.0015,
270.002 and
270.003 and
40 CFR 125.30 - 125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable after application of the best practicable control technology currently available (BPT):
NR 270.032(1)
(1) The concentration of pollutants discharged in mine drainage from mines either open-pit or underground, from which uranium, radium and vanadium ores are produced excluding mines using in-situ leach methods may not exceed:
-
See PDF for table NR 270.032(2)
(2) The concentrations of pollutants discharged from mills using the acid leach, alkaline leach or combined acid and alkaline leach process for the extraction of uranium, radium and vanadium including mill-mine facilities and mines using in-situ leach methods may not exceed:
-
See PDF for table NR 270.032 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.033
NR 270.033 Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). Except as provided in ss.
NR 270.0015,
270.002 and
270.003 and
40 CFR 125.30 - 125.32, any existing point source subject to this subcategory shall achieve the following limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT):
NR 270.033(1)
(1) The concentration of pollutants discharged in mine drainage from mines either open-pit or underground, that produce uranium ore, including mines using in-situ leach methods, may not exceed:
-
See PDF for table NR 270.033 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.034
NR 270.034 New source performance standards (NSPS). Except as provided in ss.
NR 270.0015,
270.002 and
270.003, any new source subject to this subcategory shall achieve the following NSPS representing the degree of effluent reduction attainable by the application of the best available demonstrated technology (BADT):
NR 270.034(1)
(1) The concentration of pollutants discharged in mine drainage from mines, either open-pit or underground, that produce uranium ore, excluding mines using in-situ leach methods, may not exceed:
-
See PDF for table NR 270.034(2)(a)(a) Except as provided in this subsection, there may not be discharge of process wastewater to navigable waters from mills using the acid leach, alkaline leach or combined acid and alkaline leach process for the extraction of uranium or from mines and mills using in-situ leach methods.
NR 270.034(2)(b)
(b) In the event that the annual precipitation falling on the treatment facility and the drainage area contributing surface runoff to the treatment facility exceeds the annual evaporation, a volume of water equivalent to the difference between annual precipitation falling on the treatment facility and the drainage area contributing surface runoff to the treatment facility and annual evaporation may be discharged subject to the limitations set forth in sub.
(1).
NR 270.034 History
History: Cr.
Register, October, 1986, No. 3y0, eff. 11-1-86.
NR 270.04
NR 270.04 Applicability; description of the mercury ore subcategory. The provisions of this subcategory are applicable to discharges from:
NR 270.04(1)
(1) Mines, either open-pit or underground, that produce mercury ores; and
NR 270.04(2)
(2) Mills beneficiating mercury ores by gravity separation methods or by froth-flotation methods.
NR 270.04 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.042
NR 270.042 Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT). Except as provided in ss.
NR 270.0015,
270.002 and
270.003 and
40 CFR 125.30-125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable after application of the best practicable control technology currently available (BPT):
NR 270.042(1)
(1) The concentration of pollutants discharged in mine drainage from mines, either open-pit or underground, operated for the production of mercury ores may not exceed the following limitations:
-
See PDF for table NR 270.042(2)(a)(a) Except as provided in this subsection, there may not be discharge of process wastewater to navigable waters from mills beneficiating mercury ores by gravity separation methods or by froth flotation methods.
NR 270.042(2)(b)
(b) In the event that the annual precipitation falling on the treatment facility and the drainage area contributing surface runoff to the treatment facility exceeds the annual evaporation, a volume of water equivalent to the difference between annual precipitation falling on the treatment facility and the drainage area contributing surface runoff to the treatment facility and annual evaporation may be discharged subject to the limitations set forth in par.
(a).
NR 270.042 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.043
NR 270.043 Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). Except as provided in ss.
NR 270.0015,
270.002 and
270.003 and
40 CFR 125.30-125.32, any existing point source subject to this subcategory shall achieve the following limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT):
NR 270.043(1)
(1) The concentration of pollutants discharged in mine drainage from mines, either open pit or underground, that produce mercury ores may not exceed:
-
See PDF for table NR 270.043(2)(a)(a) Except as provided in this subsection, there may not be discharge of process wastewater to navigable waters from mills beneficiating mercury ores by gravity separation methods or by froth-flotation methods.
NR 270.043(2)(b)
(b) In the event that the annual precipitation falling on the treatment facility and the drainage area contributing surface runoff to the treatment facility exceeds the annual evaporation, a volume of water equal to the difference between annual precipitation falling on the treatment facility and the drainage area contributing surface runoff to the treatment facility and annual evaporation may be discharged subject to the limitations set forth in sub.
(1).
NR 270.043 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.044
NR 270.044 New source performance standards (NSPS). Except as provided in ss.
NR 270.0015,
270.002, and
270.003, any new source subject to this subcategory shall achieve the following NSPS representing the degree of effluent reduction attainable by the application of the best available demonstrated technology (BADT):
NR 270.044(1)
(1) The concentration of pollutants discharged in mine drainage from mines either open pit or underground, that produce mercury ores may not exceed:
-
See PDF for table NR 270.044(2)(a)(a) Except as provided in this subsection, there may not be discharge of process wastewater to navigable waters from mills beneficiating mercury ores by gravity separation methods or by froth-flotation methods.
NR 270.044(2)(b)
(b) In the event that the annual precipitation falling on the treatment facility and the drainage area contributing surface runoff to the treatment facility exceeds the annual evaporation, a volume of water equal to the difference between annual precipitation falling on the treatment facility and the drainage area contributing surface runoff to the treatment facility and annual evaporation may be discharged subject to the limitations set forth in sub.
(1).
NR 270.044 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.05
NR 270.05 Applicability; description of the titanium ore subcategory. The provisions of this subcategory are applicable to discharges from:
NR 270.05(1)
(1) Mines obtaining titanium ores from lode deposits,
NR 270.05(2)
(2) Mills beneficiating titanium ores by electrostatic methods, magnetic and physical methods, or flotation methods; and
NR 270.05(3)
(3) Mines engaged in the dredge mining of placer deposits of sands containing rutile, ilmenite, leucoxene, monazite, zircon, and other heavy metals, and the milling techniques employed in conjunction with the dredge mining activity (milling techniques employed include the use of wet gravity methods in conjunction with electrostatic or magnetic methods).
NR 270.05 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 270.052
NR 270.052 Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT). Except as provided in ss.
NR 270.0015,
270.002 and
270.003 and
40 CFR 125.30-125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable after application of the best practicable control technology currently available (BPT):
NR 270.052(1)
(1) The concentration of pollutants discharged in mine drainage from mines obtaining titanium ores from lode deposits may not exceed:
-
See PDF for table NR 270.052(2)
(2) The concentration of pollutants discharged from mills beneficiating titanium ores by electrostatic methods, magnetic and physical methods, or flotation methods may not exceed:
-
See PDF for table NR 270.052(3)
(3) The concentration of pollutants discharged in mine drainage from mines engaged in the dredge mining of placer deposits of sands containing rutile, ilmenite, leucoxene, monazite, zircon, or other heavy metals, and the milling techniques employed in conjunction with the dredge mining activity (milling techniques employed include the use of wet gravity metals in conjunction with electrostatic or magnetic methods) may not exceed:
-
See PDF for table NR 270.052 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86;
Chapter NR 270 was republished to correct an error in transcription in (2) (intro.) Register October 2024 No. 826. NR 270.053
NR 270.053 Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). Except as provided in ss.
NR 270.0015,
270.002 and
270.003 and
40 CFR 125.30-125.32, any existing point source subject to this subcategory shall achieve the following limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT):
NR 270.053(1)
(1) The concentration of pollutants discharged in mine drainage from mines obtaining titanium ores from lode deposits may not exceed:
-
See PDF for table NR 270.053(2)
(2) The concentration of pollutants discharged from mills beneficiating titanium ores by electrostatic methods, magnetic and physical methods, or flotation methods may not exceed:
-
See PDF for table NR 270.053(3)
(3) The concentration of pollutants discharged in mine drainage from mines engaged in the dredge mining of placer deposits of sands containing rutile, ilmenite, leucoxene, monazite, or zircon and the milling techniques employed in conjunction with the dredge mining activity (milling techniques employed include the use of wet gravity methods in conjunction with electrostatic or magnetic methods) may not exceed:
-
See PDF for table
