Categories of standards applicable to temperature.
General water quality criteria for temperature.
Temperature criteria for limited aquatic life communities.
Ambient temperatures and water quality criteria for the protection of fish and other aquatic life.
Site-specific ambient temperatures.
Site-specific water quality criteria.
Cold shock standard.
Rate of temperature change standard.
Variances to water quality standards for temperature.
Ch. NR 102 Note
Chapter NR 102 as it existed on September 30, 1973 was repealed and a new chapter NR 102 was created, effective October 1, 1973.
Corrections made under s. 13.93 (2m) (b) 7., Stats., Register, August, 1997, No. 500
The purpose of this chapter is to establish, in conjunction with chs. NR 103
, water quality standards for surface waters of the state pursuant to s. 281.15
, Stats. This chapter describes the designated use categories for such waters and the water quality criteria necessary to support these uses. This chapter and chs. NR 103
constitute the water quality standards for the surface waters of Wisconsin.
The long-range goal of Wisconsin water quality standards is to protect the use of water resources for all lawful purposes. Water quality standards shall protect the public interest, which includes the protection of public health and welfare and the present and prospective uses of all waters of the state for public and private water supplies, propagation of fish and other aquatic life and wild and domestic animals, domestic and recreational purposes, and agricultural, commercial, industrial, and other legitimate uses. In all cases where the potential uses are in conflict, water quality standards shall protect the general public interest.
Water quality standards serve as a basis for developing and implementing control strategies to achieve legislative policies and goals. Water quality standards are the basis for deriving water quality based effluent limitations and the limitations shall be determined to attain and maintain uses and criteria, unless more stringent effluent limitations are established to protect downstream waters. Water quality standards also serve as a basis for decisions in other regulatory, permitting or funding activities that impact water quality.
NR 102.01 History
Cr. Register, February, 1989, No. 398
, eff. 3-1-89; CR 07-111
: am. (1), (2) and (3) Register September 2010 No. 657
, eff. 10-1-10.
NR 102.02 Applicability.
The provisions of this chapter are applicable to surface waters of Wisconsin.
NR 102.02 History
Cr. Register, February, 1989, No. 398
, eff. 3-1-89.
NR 102.03 Definitions.
In this chapter, the following definitions are applicable to terms used:
“Ambient temperature" means the typical existing temperature of a surface water outside the direct influence of any point source discharge, which may include daily and seasonal changes.
“Mixing zone" means a region in which a discharge of different characteristics than the receiving water is in transit and progressively diluted from the source to the receiving system.
“Natural conditions" means the normal daily and seasonal variations in climatic and atmospheric conditions, and the existing physical and chemical characteristics of a water or the course in which it flows.
“Natural temperature" means the normal existing temperature of a surface water including daily and seasonal changes outside the zone of influence of any artificial inputs.
“Resource management" means the application of control techniques to enhance or preserve a surface water in accordance with statutory provisions and in the general public interest.
“Surface waters" means all natural and artificial named and unnamed lakes and all naturally flowing streams within the boundaries of the state, but not including cooling lakes, farm ponds and facilities constructed for the treatment of wastewaters (the term waters as used in this chapter means surface waters).
“Unauthorized concentrations of substances" means pollutants or other chemicals introduced into surface waters without prior permit or knowledge of the department, but not including accidental or unintentional spills.
U.S. EPA” means the United States environmental protection agency.
NR 102.03 History
Cr. Register, September, 1973, No. 213
, eff. 10-1-73; r. (1), renum. from NR 102.01, Register, February, 1989, No. 398
, eff. 3-1-89; cr. (10), Register, May, 1993, No. 449
, eff. 6-1-93; CR 07-111
: cr. (intro.) and (1), r. (8) to (10), renum. (1) to (7) to be (2) to (8) Register September 2010 No. 657
, eff. 10-1-10; CR 19-014
: renum. (6) to NR 210.03 (10m), cr. (9) Register April 2020 No. 772
, eff. 5-1-20.
NR 102.04 Categories of surface water uses and criteria. NR 102.04(1)(1)
To preserve and enhance the quality of waters, surface water uses and criteria are established to govern water management decisions. Practices attributable to municipal, industrial, commercial, domestic, agricultural, land development or other activities shall be controlled so that all surface waters including the mixing zone meet the following conditions at all times and under all flow and water level conditions:
Substances that will cause objectionable deposits on the shore or in the bed of a body of water, shall not be present in such amounts as to interfere with public rights in waters of the state.
Floating or submerged debris, oil, scum or other material shall not be present in such amounts as to interfere with public rights in waters of the state.
Materials producing color, odor, taste or unsightliness shall not be present in such amounts as to interfere with public rights in waters of the state.
Substances in concentrations or combinations which are toxic or harmful to humans shall not be present in amounts found to be of public health significance, nor shall substances be present in amounts which are acutely harmful to animal, plant or aquatic life.
Revised uses and criteria.
The following uses and criteria may be revised as new information or advancing technology indicate that revisions are in the public interest. Water used for hydropower and commercial shipping depends mainly on quantity, depth and elevation; consequently, no specific quality criteria for these uses have been prepared.
Fish and other aquatic life uses.
All surface waters shall belong in one of the fish and other aquatic life subcategories described in this subsection. Only those use subcategories identified in pars. (a)
shall be considered suitable for the protection and propagation of a balanced fish and other aquatic life community as provided in the federal water pollution control act amendments of 1972, P.L. 92-500
; 33 USC 1251
(a) Cold water communities.
This subcategory includes surface waters capable of supporting a community of cold water fish and other aquatic life, or serving as a spawning area for cold water fish species. This subcategory includes, but is not restricted to, surface waters identified as trout water by the department of natural resources (Wisconsin Trout Streams, publication 6-3600 (80)).
(b) Warm water sport fish communities.
This subcategory includes surface waters capable of supporting a community of warm water sport fish or serving as a spawning area for warm water sport fish.
(c) Warm water forage fish communities.
This subcategory includes surface waters capable of supporting an abundant diverse community of forage fish and other aquatic life.
Limited forage fish communities.
(Intermediate surface waters). This subcategory includes surface waters of limited capacity and naturally poor water quality or habitat. These surface waters are capable of supporting only a limited community of forage fish and other aquatic life.
Limited aquatic life.
(Marginal surface waters). This subcategory includes surface waters of severely limited capacity and naturally poor water quality or habitat. These surface waters are capable of supporting only a limited community of aquatic life.
Criteria for fish and aquatic life.
Except for natural conditions, all waters classified for fish and aquatic life shall meet the following criteria:
(a) Dissolved oxygen.
Except as provided in par. (b)
and s. NR 104.02 (3)
, the dissolved oxygen content in surface waters may not be lowered to less than 5 mg/L at any time.
(b) Dissolved oxygen for cold waters.
Water bodies classified as trout waters by the department (Wisconsin Trout Streams, publication 6-3600 (80)) or as great lakes or cold water communities may not be altered from natural background dissolved oxygen levels to such an extent that trout populations are adversely affected. Additionally, all of the following conditions shall be met:
Dissolved oxygen in classified trout streams shall not be artificially lowered to less than 6.0 mg/L at any time, nor shall the dissolved oxygen be lowered to less 7.0 mg/L during the spawning season.
The dissolved oxygen in great lakes tributaries used by stocked salmonids for spawning runs shall not be lowered below natural background during the period of habitation.
The pH shall be within the range of 6.0 to 9.0, with no change greater than 0.5 units outside the estimated natural seasonal maximum and minimum.
(d) Other substances.
Unauthorized concentrations of substances are not permitted that alone or in combination with other materials present are toxic to fish or other aquatic life. Surface waters shall meet the acute and chronic criteria as set forth in or developed pursuant to ss. NR 105.05
. Surface waters shall meet the criteria which correspond to the appropriate fish and aquatic life subcategory for the surface water, except as provided in s. NR 104.02 (3)
Water quality criteria for temperature shall be determined and applied pursuant to subch. II
. Heated effluent shall not cause lethality, inside or outside of the mixing zone, to animal, plant or other aquatic life.
All surface waters shall be suitable for supporting recreational use and shall meet the criteria specified in sub. (6)
Whenever the department determines, in accordance with the procedures specified in s. NR 210.06 (3)
, that wastewater disinfection is not required to protect recreational uses, the criteria specified in par. (a)
and in chs. NR 103
do not apply.
Criteria for recreational use.
Bacteria criteria are established as follows to protect humans from illness caused by fecal contamination due to recreational contact with surface water:
NR 102.04(6)(a)1.1. `Criteria.'
All of the Escherichia coli
) criteria in Table A apply unless bacteria site-specific criteria have been adopted pursuant to subd. 2.
- See PDF for table
NR 102.04 Note
Note: The department developed the E. coli criteria in this section based on criteria developed by U.S. EPA. U.S. EPA developed the E. coli criteria using membrane filtration methods to count E. coli colony forming units. Entities wishing to use quantitative polymerase chain reaction (qPCR) and a conversion factor to compare resulting E. coli counts to the criteria in Table A may seek U.S. EPA and department approval for using alternative indicators and methods as outlined in U.S. EPA technical support document EPA-820-R-14-011.
NR 102.04 Note
Under the department's beach advisory program, a beach advisory is issued when a beach reaches the “Beach Action Value” of 235 counts per 100 mL and a beach closure is issued at 1000 counts per 100 mL, unless site-specific conditions indicate use of an alternate metric. More information on the beach advisory program is available at http://wibeaches.us
The department may establish bacteria site-specific criteria by rule to protect a waterbody's recreational use when it is determined that the statewide E. coli
criteria under subd. 1.
are inappropriate due to site-specific conditions. Once bacteria site-specific criteria are adopted in a rule and approved by U.S. EPA, those criteria supersede the statewide E. coli
criteria under subd. 1.
for that waterbody.
Any interested party may submit proposed bacteria site-specific criteria for a waterbody to the department for review and consideration. Any request for bacteria site-specific criteria must include a demonstration that the proposed site-specific criteria were developed using a U.S. EPA approved method, procedure, or test, are based on sound scientific rationale, and are as protective of the recreational use as the statewide E. coli
criteria in subd. 1.
A request for a less-stringent site-specific criteria must also demonstrate that the predominant source of the bacteria is non-human or non-fecal.
All surface waters shall be suitable for supporting public health and welfare.
Whenever the department determines a discharge of heated effluent is not exposed or situated in a manner that may pose a realistic potential for scalding of humans, the criterion specified in sub. (8) (c)
does not apply.
Criteria for public health and welfare use. NR 102.04(8)(a)
The criteria developed pursuant to ss. NR 105.08
shall be met regardless of whether the surface water is used for public drinking water supply or the applicable fish and aquatic life subcategory.
(b) Taste and odor criteria.
All surface waters providing public drinking water supplies or classified as cold water or warm water sport fish communities as described in sub. (3)
shall meet the taste and odor criteria specified or developed pursuant to s. NR 102.14
(c) Temperature criteria.
To protect humans from being scalded, the water temperature of a discharge may not exceed 120o
F unless specifically authorized under provisions in subchs. V
or VI of ch. NR 106
All surface waters shall be suitable for supporting wildlife.
NR 102.04 History
Cr. Register, September, 1973, No. 213
, eff. 10-1-73; am. (3), Register, December, 1977, No. 264
, eff. 1-1-78; renum. from NR 102.02, r. (3) (d) 1. to 3., and (5), renum. (3) (intro.) to (d) (intro.) and (e) and (4) to be (4) (intro.) to (e) and (5) and am. (4) (a), (d), (e) (intro.) and (5), cr. (6) and (7), Register, February, 1989, No. 398
, eff. 3-1-89; am. (3) (intro.), (6), (7), r. (3) (a), renum. (3) (b) to (f) to be (3) (a) to (e) and am. (3) (a), Register, August, 1997, No. 500
, eff. 9-1-97; CR 07-111
: am. (title), (1) (intro.), (2), (3) (intro.), (4) (title) and (a), r. (4) (b), (e) 1. and (5) to (7), renum. (4) (e) (intro.), 2. and 3. to be (4) (b) and am. (4) (b) (intro.), cr. (4) (e) and (5) to (9) Register September 2010 No. 657
, eff. 10-1-10; correction in (8) (c) made under s. 13.92 (4) (b) 7.
, Stats., Register September 2010 No. 657
; CR 19-014
: am. (5) (a), r. and recr. (6) Register April 2020 No. 772
, eff. 5-1-20.
NR 102.05 Application of standards. NR 102.05(1)(a)(a)
No waters of the state shall be lowered in quality unless it has been affirmatively demonstrated to the department that such a change is justified as a result of necessary economic and social development, provided that no new or increased effluent interferes with or becomes injurious to any assigned uses made of or presently possible in such waters.
(b) Classification system.
For the purposes of this subsection, all surface waters of the state, or portions thereof, shall be classified as one of the following:
Water quality standards will not be maintained under all natural occurrences of flow, temperature, or other water quality characteristics. The determination of water quality based effluent limitations or other management practices shall be based upon the following conditions except as provided in ch. NR 106
for toxic and organoleptic substances and whole effluent toxicity:
The average minimum 7-day low streamflow which occurs once in 10 years (7-day Q10
In the case of dissolved oxygen and wherever sufficient data on streamflow and temperature are available, by application of a 0.274% level of nonattainment. This is equivalent to an expected nonattainment of the dissolved oxygen criterion of one day per year.
Water quality standards shall be met at every point outside of a mixing zone. The size of the mixing zone shall be based on such factors as effluent quality and quantity, available dilution, temperature, current, type of outfall, channel configuration and restrictions to fish movement. For toxic and organoleptic substances with water quality criteria or secondary values specified in or developed pursuant to chs. NR 102
, allowable dilution shall be determined as specified in ch. NR 106
in addition to the requirements specified in this subsection. As a guide to the delineation of a mixing zone, the following shall be taken into consideration:
Limiting mixing zones to as small an area as practicable, and conforming to the time exposure responses of aquatic life.
Providing passageways for fish and other mobile aquatic organisms.
Where possible, mixing zones being no larger than 25% of the cross–sectional area or volume of flow of a flowing water body and not extending more than 50% of the width.
Final acute criteria and secondary values specified in or developed pursuant to s. NR 105.05
for the fish and aquatic life subcategory for which the receiving water is classified not being exceeded at any point in the mixing zone.