Chapter NR 102

Chapter NR 102

WATER QUALITY STANDARDS FOR WISCONSIN SURFACE WATERS

Subchapter I — General

NR 102.01   Purpose.

NR 102.02   Applicability.

NR 102.03   Definitions.

NR 102.04   Categories of surface water uses and criteria.

NR 102.05   Application of standards.

NR 102.06   Phosphorus.

NR 102.07   Assessing phosphorus concentration.

NR 102.10   Outstanding resource waters.

NR 102.11   Exceptional resource waters.

NR 102.12   Great Lakes system.

NR 102.13   Fish and aquatic life waters.

NR 102.14   Taste and odor criteria.

Subchapter II — Water Quality Standards for Temperature

NR 102.20   Purpose.

NR 102.22   Definitions.

NR 102.23   Categories of standards applicable to temperature.

NR 102.24   General water quality criteria for temperature.

NR 102.245   Temperature criteria for limited aquatic life communities.

NR 102.25   Ambient temperatures and water quality criteria for the protection of fish and other aquatic life.

NR 102.26   Site-specific ambient temperatures.

NR 102.27   Site-specific water quality criteria.

NR 102.28   Cold shock standard.

NR 102.29   Rate of temperature change standard.

NR 102.30   Variances to water quality standards for temperature.

Subchapter III — Waterbody Assessments and Reporting

NR 102.50   Waterbody assessments and reporting.

NR 102.51   Assessment types.

NR 102.52   Assessment protocols.

NR 102.53   Reporting, public participation, and approvals.

NR 102.54   Biological assessment of designated uses.

NR 102.55   Narrative biological assessment thresholds for aquatic life uses.

NR 102.56   Numeric biological assessment thresholds for lakes, reservoirs and impounded flowing waters.

NR 102.60   Combined assessment procedure for phosphorus.

Ch. NR 102 Note Note: Chapter NR 102 as it existed on September 30, 1973 was repealed and a new chapter NR 102 was created, effective October 1, 1973.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.

subch. I of ch. NR 102 Subchapter I — General

NR 102.01 NR 102.01 Purpose.

NR 102.01(1) (1) The purpose of this chapter is to establish, in conjunction with chs. NR 103 to 105, 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, chs. NR 103 to 105, and ch. NR 119 constitute the water quality standards for the surface waters of Wisconsin.

NR 102.01(2) (2) 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.

NR 102.01(3) (3) 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 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; CR 19-093: am. (1) Register September 2022 No. 801, eff. 10-1-22.

NR 102.02 NR 102.02 Applicability. The provisions of this chapter are applicable to surface waters of Wisconsin.

NR 102.02 History History: Cr. Register, February, 1989, No. 398, eff. 3-1-89.

NR 102.03 NR 102.03 Definitions. In this chapter, the following definitions apply:

NR 102.03(1) (1) “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.

NR 102.03(1c) (1c) “Benthic” means relating to the ecological zone at the bottom of a body of water, including the sediment surface and subsurface layers.

NR 102.03(1e) (1e) “Biological assessment threshold” means a numeric value or condition description used to measure the quality of a waterbody’s biological community and to determine attainment of its designated uses.

NR 102.03(1g) (1g) “Chlorophyll a” means a green pigment present in all green plants and in cyanobacteria, responsible for the absorption of light to provide energy for photosynthesis.

NR 102.03(1i) (1i) “Clean Water Act” means the federal Clean Water Act of 1972 and amendments.

NR 102.03(1k) (1k) “Confidence interval” means a range within which the true value of a parameter is likely to occur, with a specified level of confidence.

NR 102.03(1m) (1m) “Diatom” means a common and diverse group of unicellular algae of the phylum Chrysophyta, having cell walls containing silica.

NR 102.03(1o) (1o) “Drainage lake” means a lake with an outlet stream that continually flows under average summer conditions based on the past 30 years.

NR 102.03(1q) (1q) “Impounded flowing water” means a waterbody impounded by a constructed outlet structure on a river or stream that is not a reservoir as defined in sub. (4s).

NR 102.03(1v) (1v) “Macrophyte” means an aquatic plant large enough to be seen without the use of a microscope.

NR 102.03(2) (2) “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.