Section NR 104.02 - Surface water classifications and effluent limitations(1) Hydrologic classification. "Surface waters" as defined in s. NR 102.03(7), may be classified according to their hydraulic or hydrologic characteristics. For purposes of this chapter, surface waters will be classified by the department into one of the following categories:(a)Lakes or flowages. This classification includes bodies of water whose current is more or less stagnant or which lacks a unidirectional current.(b)Diffused surface waters. This classification includes any water from rains, intermittent springs or melting snow which flows on the land surface, through ravines, etc., which are usually dry except in times of runoff. This category does not include waters at the land surface in the vicinity of agricultural or waste-water irrigation disposal systems.(c)Wetlands. This classification includes areas where water is at, near, or above the land surface long enough to be capable of supporting aquatic or hydrophytic vegetation and which have soils indicative of wet conditions.(d)Wastewater effluent channels. This classification includes discharge conveyances constructed primarily for the purpose of transporting wastes from a facility to a point of discharge. Drainage ditches (including those established under ch. 88, Stats.) constructed primarily for the purposes of relieving excess waters on agricultural lands shall not be construed as effluent channels. Modifications made to natural watercourses receiving wastewater effluents for the purpose of increasing or enhancing the natural flow characteristics of the stream shall not be classified as effluent channels.(e)Noncontinuous streams. This classification includes watercourses which have a defined stream channel, but have a natural 7-day Q flow of less than 0.1 cfs and do not exhibit characteristics of being perpetually wet without wastewater discharges.(f)Continuous streams. This classification includes watercourses which have a natural 7-day Q flow of greater than 0.1 cfs or which exhibit characteristics of a perpetually wet environment, are generally capable of supporting a diverse aquatic biota and flow in a defined stream channel. Note: The application of this classification system is not dependent on the navigability properties of the watercourse, but is dependent upon the quantity-quality relationships of the surface water.
(2) Water quality classification. (a) Whenever the goals as specified in s. 283.001(1) (b), Stats., cannot be attained because of conditions enumerated in s. NR 104.01(1), a variance may be provided. Variances from a specific water quality criteria may be given in s. NR 104.05 et. seq. or a variance under one of the categories provided in this chapter may be specified.(b) Practices attributable to municipal, industrial, commercial, domestic, agricultural, land development, or other activities shall be controlled so that waters regardless of their hydrologic and water quality classifications meet the general aesthetic and acute toxicity conditions in s. NR 102.04(1).(3) Variance categories. (a)Limited forage fish communities (intermediate surface waters).1. Applicability. This category of variance may be applied to either the continuous or non-continuous stream hydrologic classification.2. Surface water criteria. The following water quality criteria shall be met in all surface waters included in this variance category:a. Dissolved oxygen shall not be less than 3 mg/L.c. The pH shall be within the range of 6.0 to 9.0.d. All other substances shall meet the acute and chronic toxicity criteria for limited forage fish communities specified in or developed pursuant to ss. NR 105.05 and 105.06.3. Effluent criteria. a. The effluent limitations determined necessary to meet the surface water criteria listed above are enumerated in table 1. TABLE 1
Parameter | Monthly Average (mg/L) | Daily Maximum (mg/L) | Weekly Average (mg/L) | Other (mg/L) |
BOD5 | 15 | 30 | - | - |
Total Suspended Solids | 20 | 30 | - | - |
Dissolved Oxygen | - | - | - | 4 (minimum) |
b. Unless otherwise specified in table 1 above, effluent limitations for sewage treatment works shall be as adopted in ch. NR 210.c. In addition to the effluent limitations enumerated in table 1, effluent limitations for these and any other substance necessary to protect assigned uses shall be met, including water quality based effluent limitations necessary to meet the criteria specified in or developed pursuant to ss. NR 105.05 and 105.06 for limited forage fish communities.(b)Limited aquatic life subcategory (marginal surface waters).1. Applicability. This variance category may be applied to the continuous or noncontinuous stream hydrologic classification, except that it shall be applied to all surface waters classified as effluent channel, wetland or diffuse surface water.2. Surface water criteria. The following surface water quality criteria shall be met in all surface waters included in this variance category: a. Dissolved oxygen shall not be less than 1 mg/L.b. The pH shall be within the range of 6.0 to 9.0.c. All other substances shall meet the acute and chronic toxicity criteria for the limited aquatic life subcategory specified in or developed pursuant to ss. NR 105.05 and 105.06.3. Effluent criteria. a. The effluent limitations determined necessary to meet the surface water criteria listed above are enumerated in table 2. TABLE 2
Parameter | Monthly Average (mg/L) | Weekly Average (mg/L) | Other (mg/L) |
BOD5 | 20 | 30 | - |
Total Suspended | 20 | 30 | - |
Solids | | | |
Dissolved Oxygen | - | - | 4 (minimum) |
b. Unless otherwise specified in table 2 above, effluent limitations for sewage treatment works shall be as adopted in ch. NR 210.c. In addition to the effluent limitations enumerated in table 2, effluent limitations for these and any other substance necessary to protect assigned uses shall be met, including water quality based limitations necessary to meet the criteria for limited aquatic life surface water specified in or developed pursuant to ss. NR 105.05 and 105.06.(4) Other classifications and effluent criteria. (a)Surface waters significant to the environmental integrity of the state or region. Under all hydrologic categories, the department reserves the right to require other effluent limitations, including allocation of wasteloads for organic material, toxicants and chlorine residuals if it is determined that the specified surface water is important to the overall environmental integrity of the area. In waters identified as trout streams, located in scientific areas or wild and scenic areas, providing endangered species habitat or of high recreational potential, effluent criteria will be evaluated on a case-by-case basis.(b)Surface waters classified for fish and aquatic life.1. Streams. Where flowing streams or rivers are specified to achieve fish and aquatic life criteria, wasteload allocation for organic material, toxicants and chlorine residuals shall determine effluent criteria necessary to achieve that standard.2. Lakes and flowages. Effluent characteristics for discharges to lakes or flowages shall be based upon an evaluation of water quality necessary to protect fish and aquatic life taking into account mixing zone and nutrient removal criteria.3. Minimum effluent criteria. If it can be reasonably demonstrated that the quality of the surface water is independent of a wastewater discharge, effluent limitations established under ss. 283.13 and 283.19, Stats., shall apply.(c)Wastewater treatment lagoons. Effluents from fill-and-draw wastewater treatment lagoons or domestic waste stabilization ponds discharging to waters receiving a variance in this chapter may be permitted to vary from the limitations specified in table 1 or 2 provided the following conditions are met: 1. The discharge occurs only during the spring and fall of the year when the flow in the receiving water is normally high, and the temperature is low. The rate of discharge shall not exceed that specified in a permit under s. 283.31, Stats., or where no rate is indicated, the allowable discharge quantities shall be determined by the department based upon current evaluation of the receiving water.2. In lieu of the previous conditions, the discharge from a fill-and-draw lagoon may occur at any time provided the rate does not exceed the assimilative capacity of the receiving water as specified in a permit under s. 283.31, Stats.3. The dissolved oxygen in the effluent is maintained at a level greater than or equal to 4 mg/L, and the permitted rate of discharge shall be such that the dissolved oxygen and ammonia nitrogen criteria necessary to sustain fish and aquatic life are maintained in the stream during the period of discharge.4. The effluent limitations do not exceed those established under ss. 283.13 and 283.19, Stats.(5) Changes in classification. Surface waters which exhibit changing hydrologic and quality characteristics shall be classified accordingly. Effluent criteria for upstream discharges shall be based upon the most critical downstream classification and shall be specified by the department either on the basis of justified inference or by the application of a wasteload allocation analysis. Any subsequent changes in a stream's morphology or potential may necessitate the reevaluation of the classification.Wis. Admin. Code Department of Natural Resources NR 104.02
Cr. Register, September, 1976, No. 249, eff. 10-1-76; am. Tables 1 and 2, (2), (3) (a) 2a and d., (3) (b) 2a and c., (4) (c), Register, December, 1977, No. 264, eff. 1-1-78; am. (3) (a) 2a, Register, June, 1978, No. 270, eff. 7-1-78; am. (1) (c), Register, June, 1984, No. 342, eff. 2-1-84; r. (3) (a) 2. b. to d., (b) 2. b. and c., renum. (3) (a) 2. e. to g. and (3) (b) 2. d. and e. to be (3) (a) 2. b. to d. and (3) (b) 2. b. and c. and am (3) (a) 2. g. and (3) (b) 2. c., am. (3) (a) 3. a. and (3) (b) 3. a., Register, October, 1986, No. 370, eff. 11-1-86; am. (1) (intro.), (2) (b), (3) (a) (intro.) and 3. c., and (3) (b) 3. c., r. and recr. (3) (a) 2. d. and (3) (b) 2. c., Register, February, 1989, No. 398, eff. 3-1-89; CR 03-050: r. (3) (a) 2. b., am. Table 1 Register February 2004 No. 578, eff. 3-1-04.Amended by, correction in (1) made under s. 35.17, Stats., Register April 2020 No. 772, eff. 5/1/2020Amended by, correction in (1) made under s. 13.92(4) (b) 6, Stats., Register September 2020 No. 777, eff. 10/1/2020