Chapter NR 207

Chapter NR 207

ANTIDEGRADATION AND ANTIBACKSLIDING

Subchapter I — Antidegradation

NR 207.01   Purpose and applicability.

NR 207.02   Definitions.

NR 207.03   Antidegradation evaluation procedure.

NR 207.04   Fish and aquatic life waters.

NR 207.05   Determining significant lowering of water quality.

Subchapter II — Antibacksliding

NR 207.10   Purpose and applicability.

NR 207.11   Definitions.

NR 207.12   Antibacksliding.

Ch. NR 207 Note Note: Corrections made under s. 13.93 (2m) (b) 7., Stats., Register, August, 1997, No. 500.

subch. I of ch. NR 207 Subchapter I — Antidegradation

NR 207.01 NR 207.01 Purpose and applicability.

NR 207.01(1) (1) Purpose. The purpose of this subchapter is to establish implementation procedures for the antidegradation policy in s. NR 102.05 (1) (a). This subchapter sets procedures applicable to proposed new or increased discharges to outstanding resource waters, exceptional resource waters, Great Lakes system waters, fish and aquatic life waters, and waters listed in tables 3 through 8 in ss. NR 104.05 to 104.10.

NR 207.01(2) (2) Applicability. This subchapter applies to any person proposing to increase an existing discharge or create a new discharge to the surface waters of the state.

NR 207.01 History History: Cr. Register, February, 1989, No. 398, eff. 3-1-89; am. (1), Register, August, 1997, No. 500, eff. 9-1-97; CR 17-002: am. Register April 2018 No. 748, eff. 5-1-18.

NR 207.02 NR 207.02 Definitions. In addition to the definitions in ch. NR 205, the following definitions apply to this chapter:

NR 207.02(1) (1) “Assimilative capacity” means the difference between the water quality criterion for a substance identified in ch. NR 102 or 105 and the existing level of that substance in a surface water.

NR 207.02(2) (2) “Bioaccumulation factor” means the ratio of the concentration of a substance in an aquatic organism to the concentration of the substance in water to which the organism is exposed regardless of whether the concentration in the organism results solely from body contact with the water or from body contact plus ingestion of food contaminated with the substance, as determined under ch. NR 105 and associated technical support documents.

NR 207.02(3) (3) “Exceptional resource waters” means any surface water, or portion thereof, in s. NR 102.11.

NR 207.02(4) (4) “Fish and aquatic life water” means any surface water, or portion thereof, in s. NR 102.13.

NR 207.02(5) (5) “Great Lakes system” means any surface water in s. NR 102.12 (1).

NR 207.02(6) (6) 

NR 207.02(6)(a) (a) “Increased discharge” means any change in concentration, level or loading of a substance which would exceed an effluent limitation specified in a current WPDES permit.

NR 207.02(6)(b) (b) Except as provided in par. (c), increased discharge does not include the initial imposition of effluent limitations for substances which were in a previous discharge but which had not been limited in a prior or the current permit unless the initial imposition of effluent limitations occurs due to a changed discharge location, other than a change in location necessary to accommodate a mixing zone as provided for in ch. NR 106.

NR 207.02(6)(c) (c) For discharges of bioaccumulative chemicals of concern (BCCs), defined in s. NR 105.03 (9), to the Great Lakes system, increased discharge means:

NR 207.02(6)(c)1. 1. An increased discharge as defined in par. (a);

NR 207.02(6)(c)2. 2. The initial imposition of an effluent limitation for a BCC that occurs due to an actual or expected increase in loading of the BCC; and

NR 207.02(6)(c)3. 3. Any actual or expected increase in loading of a BCC which is caused by or will be caused by a facility expansion, a process modification, or the connection to an existing public or private wastewater treatment system of a substantial source of untreated or pretreated effluent containing BCCs, and which requires notification to the department pursuant to s. NR 205.07 (2) (a) or (3) (c) or (d). Under this subdivision, increased discharge does not include any increase in the loading of BCCs that is caused by normal operational variability, changes in intake pollutants or increasing the rate or hours of production within the existing production capacity. Normal operational variability includes, for POTWs, any additional wastewater volume within the existing capacity of the POTW from commercial, industrial or residential growth which do not normally contribute substantial quantities of BCCs to the POTW’s wastewater flow.

NR 207.02(7) (7) “Loading” means the concentration of a substance within a discharge multiplied by the flow of that discharge.

NR 207.02(8) (8) “New discharge” means any point source which has not received a WPDES permit from the department prior to March 1, 1989.

NR 207.02(9) (9) “Outstanding resource waters” means any surface water, or portion thereof, in s. NR 102.10.

NR 207.02(10) (10) “Receiving water” means the portion of a surface water which will be affected by a proposed new or increased discharge.

NR 207.02(11) (11) “Significant lowering of water quality” means a lowering of water quality determined to be significant under s. NR 207.05.

NR 207.02(12) (12) “Surface water” means all waters of the state, as designated in s. 281.01 (18), Stats., except groundwater.

NR 207.02(13) (13) “Water quality based effluent limitations” means effluent limitations established by the department pursuant to s. 283.13 (5), Stats.

NR 207.02 History History: Cr. Register, February, 1989, No. 398, eff. 3-1-89; correction in (13) made under s. 13.93 (2m) (b) 7., Stats., Register, March, 1997, No. 495; am. (5), (6) (b) and (12), cr. (6) (c), Register, August, 1997, No. 500, eff. 9-1-97; correction in (12) made under s. 35.17, Stats., Register Aril 2018 No. 748.

NR 207.03 NR 207.03 Antidegradation evaluation procedure.

NR 207.03(1) (1) General. When the department promulgates a less stringent criterion for a non-BCC pursuant to s. NR 105.02 (2) or revises a secondary value for a non-BCC due to an updated scientific database, any subsequent requests for increased permit limitations based on the revised criterion or secondary value will not be subject to the requirements of this chapter if the following occur:

NR 207.03(1)(a) (a) The department determines that the increased limitations based on the changed criterion or secondary values will still maintain and protect the existing designated uses, and

NR 207.03(1)(b) (b) The receiving water is not an outstanding resource water, an exceptional resource water subject to the requirements of sub. (4) (b), or a water for which sub. (7) (c) applies.

NR 207.03(2) (2) Dissolved-based metal limitations. If a person requests an increased limitation based on a dissolved metals criterion pursuant to s. NR 106.07 (7) (b), the request for an increased limitation will not be subject to the requirements of this chapter if the following occur:

NR 207.03(2)(a) (a) The department determines that the increase limitations based on the changed criterion or secondary value will still maintain and protect the existing designated uses, and

NR 207.03(2)(b) (b) The receiving water is not an outstanding resource water, an exceptional resource water subject to the requirements of sub. (4) (b), or a water for which sub. (7) (c) applies.

NR 207.03(3) (3) Outstanding resource waters. If the department determines that a WPDES permit application proposes a new or increased discharge to outstanding resource waters, effluent limitations for substances in the new or increased portion of the discharge will be set equal to the background levels of these substances, upstream of, or adjacent to, the discharge site unless it is determined that for Great Lakes system waters, such limitations would result in significant lowering of water quality under s. NR 207.05 (4) (b). Effluent limitations for those substances shall be determined in accordance with s. NR 207.04.

NR 207.03(4) (4) Exceptional resource waters. If the department determines that a WPDES permit application proposes a new or increased discharge to exceptional resource waters, it shall review the application as follows:

NR 207.03(4)(a) (a) For a proposed new discharge which is needed to prevent or correct either an existing surface or groundwater contamination situation, or a public health problem, water quality based effluent limitations shall be determined in accordance with sub. (6).

NR 207.03(4)(b) (b) For a proposed new discharge which is not needed to prevent or correct either an existing surface or groundwater contamination situation, or a public health problem, water quality based effluent limitations shall be set equal to the existing levels of these substances upstream of, or adjacent to, the discharge site.

NR 207.03(4)(c) (c) For a proposed increased discharge, water quality based effluent limitations for the increased portion of the discharge shall be determined in accordance with sub. (6).

NR 207.03(4)(d) (d) Whenever effluent limitations determined in accordance with pars. (a) to (c) would result in any substance in the proposed new or increased discharge causing significant lowering of water quality as determined under s. NR 207.05 (4) (b), effluent limitations shall be determined in accordance with s. NR 207.04.

NR 207.03(5) (5) Great lakes system. If the department determines that a WPDES permit applicant proposes a new or increased discharge to the Great Lakes system, it shall establish effluent limitations using the procedures in ss. NR 207.04 and 207.05; except for proposed new or increased discharges of the pollutants identified in s. NR 102.12 (3) to waters of the Lake Superior basin. No new or increased discharge of those pollutants identified in s. NR 102.12 (3) may be permitted unless the applicant certifies at time of application that the proposed new or increased discharge is necessary after utilizing best technology in process or control using commercially available techniques with demonstrated performance levels for similar applications.

NR 207.03(6) (6) Fish and aquatic life waters. If the department determines that a WPDES permit application proposes a new or increased discharge to fish and aquatic life waters, it shall establish effluent limitations using the procedures in ss. NR 207.04 and 207.05.

NR 207.03(7) (7) Waters listed in tables 3 through 8 in ss. NR 104.05 to 104.10. If the department determines that a WPDES permit application proposes a new or increased discharge to waters listed in tables 3 through 8 in ss. NR 104.05 to 104.10, the following procedure shall apply:

NR 207.03(7)(a) (a) The person proposing a new or increased discharge shall demonstrate to the department whether or not the discharge will result in:

NR 207.03(7)(a)1. 1. Significant lowering of water quality in downstream fish and aquatic life or Great Lakes system waters as determined under s. NR 207.05;