RULE TEXT
Section 1 NR 102.03 (intro.) is amended to read:
NR 102.03 Definitions. In this chapter, the following definitions are applicable to terms usedapply:
Section 2 NR 102.03 (1c), (1e), (1g), (1i), (1k), (1m), (1q), (1v), and (6)(6d), and (9) are created to read:
NR 102.03 (1c) “Benthic” means relating to the ecological zone at the bottom of a body of water, including the sediment surface and subsurface layers.
(1e) “Biocriterion” means a surface water quality criterion under subch. III that describes the structure and function of aquatic communities in a waterbody necessary to protect its designated aquatic life use. “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.
(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.
(1i) “Clean Water Act” means the federal Clean Water Act of 1972 and amendments.
(1k) “Confidence interval” means a range within which the true value of a parameter is likely to occur, with a specified level of confidence.
(1m) “Diatom” means a common and diverse group of unicellular algae of the phylum Chrysophyta, having cell walls containing silica.
(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. (4m).
(1v) “Macrophyte” means an aquatic plant large enough to be seen without the use of a microscope.
(6d)(6) “Section 303 (d) list” means a list of waters that do not attain water quality standards and require a total maximum daily load analysis, as specified under section 303 (d) of the Clean Water Act, 33 USC 1313 (d). (9) “U.S. EPA” means the United States environmental protection agency.
Section 3 NR 102.04 (4) (a) is repealed and recreated to read:
NR 102.04 (4) (a) Dissolved oxygen. 1. For streams, rivers, and impounded flowing waters, dissolved oxygen criteria apply to samples taken from the main channel near the area with greatest flow. For lakes or reservoirs, the dissolved oxygen criteria in this paragraph apply to the epilimnion of stratified lakes and to all but the deepest one meter of the water column of unstratified lakes.
2. Except as provided in subds. 3. to 7. and par. (am), surface waters shall attain a minimum dissolved oxygen concentration of 5 mg/L at all times.
3. A waterbody classified by the department as a trout class I or II water under s. NR 1.02 (7), a cold water community that is not a two-story fishery lake covered under par. (am), or a great lakes tributary used by salmonids for spawning during the period of habitation, shall attain all of the following: a. A minimum dissolved oxygen concentration of 6.0 mg/L at all times.
b. A minimum dissolved oxygen concentration of 7.0 mg/L when cold water fish are spawning through fry emergence from their redds, or gravel nests.
Note: The period from spawning through fry emergence from their gravel nests is approximately mid-October through April, but varies depending on water temperature and location in the state.
c. Dissolved oxygen concentrations and diurnal patterns may not be altered from natural background levels to such an extent that cold water populations are adversely affected.
4. A waterbody classified by the department as trout class III under s. NR 1.02 (7) shall attain a minimum dissolved oxygen concentration of 6.0 mg/L at all times. 5. A waterbody for which a use attainability analysis under 40 CFR 131.10 (g) (1) to (6) demonstrates that its otherwise applicable designated use category is unattainable shall attain the following: a. For a coldwater community with an approved use attainability analysis, a minimum dissolved oxygen concentration of 5 mg/L at all times.
b. For any other community, a minimum dissolved oxygen concentration of 3 mg/L at all times.
Note: Waterbodies described in subd. 5 are also known as altered warmwater or altered macroinvertebrate waters.
6. A waterbody designated by the department as limited forage fish shall attain a minimum dissolved oxygen concentration of 3 mg/L at all times.
7. A waterbody designated by the department as limited aquatic life or wetlands, or classified as diffuse surface waters or wastewater effluent channels shall attain a minimum dissolved oxygen concentration of 1 mg/L at all times when water is present.
Section 4 NR 102.04 (4) (am) is created to read:
NR 102.04 (4) (am) Oxythermal layer thickness for two-story fishery lakes. 1. ‘Criteria.’ A two-story fishery lake shall maintain, during its period of summer stratification, an oxythermal layer of at least 1 meter in thickness that maintains both a dissolved oxygen concentration of at least 6 mg/L and a maximum temperature of the following:
a. For a two-story fishery lake with lake trout, 57° F or less.
b. For a two-story fishery lake with whitefish but not lake trout, 66° F or less.
c. For a two-story fishery lake with cisco but not whitefish or lake trout, or that the department manages for brook, brown, or rainbow trout, 73°F or less.
d. For a two-story fishery lake with multiple coldwater fish species, the applicable criterion under subd. 1. a. to c. is that for the lake’s species requiring the lowest temperature.
2. ‘Assessment.’ a. The monitoring period for the criteria under subd. 1. is June 1 to September 15. When monitoring for assessment purposes, depth profiles of temperature and dissolved oxygen shall, whenever possible, be taken in increments of 1 meter or less near the deepest part of the lake, at least monthly July to September. Samples taken outside this time frame but during summer stratification may also be used to determine assessment.
Note: Reservoirs, multi-lobed lakes, or very large lakes may need more than one sampling station to assess the lake.
b. If at any time during a lake’s summer stratification the applicable criterion in subd. 1. is not met, that year is an exceedance year. At least 2 years of data are needed to make an impairmentattainment determination. If any 2 or more years within the most recent 5-year period are exceedance years, the lake is not attaining the water quality criterion and shall be listed on the section 303 (d) list. If insufficient data are available from the most recent 5-year period, data from up to 10 years may be used if representative of current conditions.
Section 5 NR 102.04 (4) (b) is repealed.
Section 6 NR 102.04 (4) (d) is amended to read:
NR 102.04 (4) (d) OtherToxic 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 and 105.06. 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). Section 7 NR 102.04 (4) (f) and (Note) and (g) areis created to read:
NR 102.04 (4) (f) Chlorophyll a. 1. ‘Criteria.’ a. Mean suspended chlorophyll a concentrations in lakes and reservoirs other than stratified two-story fishery lakes shall not exceed 27 ug/L.
b. Mean suspended chlorophyll a concentrations in stratified two-story fishery lakes shall not exceed 8 ug/L.
2. ‘Assessment.’ Data requirements are the same as those specified in s. NR 102.07 (1) (a) 1., except that the sampling period for chlorophyll a is July 15 to September 15. To determine attainment of the chlorophyll a criterion under subd. 1., the department shall compare the waterbody’s mean suspended chlorophyll a concentration during the sampling period to the criterion, using the confidence interval approach described under s. NR 102.52 (2) (b) to (c) to determine if additional samples are needed. Note: The aquatic life chlorophyll a criteria do not apply to streams, rivers, or impounded flowing waters, as they were established based on lake trophic status levels.
(g)NR 102.04 (4) (f) Other criteria. Surface waters shall meet all other criteria that correspond to the appropriate aquatic life subcategory for the surface water, including narrative criteria specified in sub. (1) and biocriteria described in subch. III.
Section 8 NR 102.04 (5) (b) is amended to read:
NR 102.04 (5) (b) Exceptions. 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)sub. (6) (a) and in chs. NR 103 and 104 do not apply. Section 9. NR 102.04 (6) (b), Table B, (Note 1), and (Note 2) are created to read:
[Note to LRB: NR 102.04 (6) (a) and Table A are created in Board Order WY-17-15.]
NR 102.04 (6) (b) Frequency of moderate algae levels. 1. ‘Criteria.’ A moderate algae level is defined as a chlorophyll a concentration of 20 ug/L or greater. Lakes, reservoirs, and impounded flowing waters shall not exceed the frequency of moderate algae levels specified in Table B during the summer sampling period.
Table B
Recreational use criteria for frequency of moderate algae levels
Waterbody Type1 | Subcategory | Criteria for frequency of moderate algae levels |
Lakes, Reservoirs, Impounded Flowing Waters (includes cold and warm) | Impounded flowing water, Unstratified drainage, Unstratified seepage | Does not exceed 20 ug/L chlorophyll a for more than 30% of days during the summer sampling period2 |
| Stratified drainage, Stratified seepage | Does not exceed 20 ug/L chlorophyll a for more than 5% of days during the summer sampling period2 |
| Stratified two-story fishery | |
1 Terms used for waterbody types and subcategories are defined in s. NR 102.03. 2 Summer sampling period is July 15 to September 15.
Note: Lakes and reservoirs are subcategorized based on both their stratification status (stratified vs. unstratified) and whether or not they have an outlet stream or river (drainage vs. seepage). To find a lake or reservoir’s subcategory, also known as its natural community, go to the department’s Surface Water Data Viewer online map at https://dnr.wi.gov/topic/surfacewater/swdv/ and turn on the layer for Surface Water: Lake Natural Communities. On the natural communities layer, unstratified is referred to as “shallow”, and stratified is referred to as “deep.” Headwater and lowland lakes are types of drainage lakes. Note: The EPA has set human health swimming advisory levels for microcystin and cylindrospermopsin that accurately reflect the latest scientific information on the potential human health effects from recreational exposure to these two cyanotoxins. The department recommends that local and tribal public health agencies use these swimming advisory levels for notification purposes in recreational waters to protect the public. More information can be found at https://dnr.wi.gov/lakes/bluegreenalgae/Default.aspx. 2. ‘Assessment.’ Data requirements are the same as those specified in s. NR 102.07 (2) (a) 1., except that the sampling period for chlorophyll a in all waterbody types is July 15 to September 15. To determine attainment of the criterion, the department shall statistically determine a waterbody’s frequency of moderate algae levels during the chlorophyll a summer sampling period using the confidence interval approach as described under s. NR 102.52 (2) (b) and (c) and compare that frequency to the applicable criterion in Table B. Section 910. NR 102.06 (1) and (2) (intro.) areis amended to read:
NR 102.06 (1) General. This section identifies the water quality criteria for total phosphorus that shall be met in surface waters. Assessment procedures for waterbodies are specified in s.ss. NR 102.07 and 102.60. Section 11. NR 102.06 (2) (intro.) is amended to read:
NR 102.06 (2) Definitions. In this section, the following definitions apply:
Section 1012. NR 102.06 (2) (a), (f), and (fm), and (j) are renumbered 102.03 (1o), (4m)(4s) and (6h)., (6e), and (7m).
[Note to LRB: A separate rule package, WY-23-19, creates a definition for NR 102.03 (4e) and (4m), which affects the numbering of definition (4s) renumbered under this Section.]
Section 1113. NR 102.06 (2) (g) and (2) (i) are renumbered 102.03 (6p)(6m) and (6t)(6s) and amended to read:
NR 102.03 (6p)(6m) “Stratified lake or reservoir” means a lake or reservoir where either of sufficient field data demonstrate that the lake is dimictic or, in absence of sufficient field data, the following equationsequation results in a value of greater than 3.8:
Maximum Depth (meters) — 0.1
Log10Lake Area (hectares)
Maximum Depth (feet)* 0.305 — 0.1
Log10Lake Area (acres) * 0.405
(6t)(6s) “Stratified two-story fishery lake” means a stratified lake which has supported a cold water fishery in its lower depths within the last 50 yearsor “two-story fishery lake” means a lake greater than 5 acres in size that is typically stratified in the summer, with the potential for an oxygenated hypolimnion, that has documentation since 1975 of a population of cold water fish species such as cisco, whitefish, or trout that is sustained through natural reproduction or long-term active stocking with year-to-year survival.
Section 1214. NR 102.03 (6t)(6s) (Note) is created to read:
NR 102.03 (6t)(6s) Note: A list of two-story fishery lakes that contain naturally reproducing lake trout, whitefish, or cisco, or are stocked and managed by the department for brook, brown, rainbow, or lake trout, is available on the department’s designated uses website at https://dnr.wi.gov/topic/SurfaceWater/usedesignations.html. Section 1315. NR 102.06 (3) (title) is repealed and recreated to read:
NR 102.06 (3) (title) Rivers, streams, and impounded flowing waters.
Section 1416. NR 102.06 (4) (c) is renumbered 102.06 (3) (c) and amended to read:
NR 102.06 (3) (c) Waters impounded on rivers or streams that don’t meet the definition of reservoir in this sectionAn impounded flowing water shall meet the river andor stream criterion in sub. (3)par. (a) or (b) that applies to the primary stream or river entering the impounded water.
Section 1517. NR 102.06 (7) (Note 2) is repealed. [Note that Board Order WY-09-18 renumbers (7) to (7) (a).]
Section 1618. NR 102.07 is created to read:
NR 102.07 Phosphorus assessment procedures. (1) Definitions. In this section, the following definitions apply:
(b) “Weather-controlled total phosphorus concentration” means a waterbody’s mean or median total phosphorus concentration during the applicable assessment period, estimated from measured data while controlling for weather variability using a method such as the department’s Phosphorus Mixed Effects Regression calculation method.
