8. Summary of Factual Data and Analytical Methodologies Used and How Any Related Findings Support the Regulatory Approach Chosen:
The methodology identified in this rule package is based on Clean Water Act and Great Lake Initiative requirements and on EPA guidance including the Technical Support Document for Water Quality-based Toxics Control (March 1991). PB91-127415.
9. Analysis and Supporting Documents Used to Determine the Effect on Small Business or in Preparation of an Economic Impact Report:
[insert after EIA].
10. Effect on Small Business (initial regulatory flexibility analysis):
[insert after EIA].
11. Agency Contact Person:
Amanda Minks
Department of Natural Resources
Bureau of Water Quality WQ/3
101 South Webster Street
P.O. Box 7921
Madison, WI 53707-7921
608-264-9223
12. Place where comments are to be submitted and deadline for submission:
Written comments may be submitted at the public hearings, by regular mail, fax or email to:
Amanda Minks
Department of Natural Resources
101 South Webster Street
P.O. Box 7921
Madison, WI 53707-7921
Phone: 608-264-9223
Fax: 608-267-2800
Section 1 NR 106.03 (1) is renumbered NR 106.03 (1r).
NR 106.03 (1r) "Bioaccumulative chemical of concern" or "BCC" means any substance that has the potential to cause adverse effects which, upon entering the surface waters, accumulates in aquatic organisms by a human health or wildlife bioaccumulation factor greater than 1000.
Section 2 NR 106.03 (1g) is created to read:
NR 106.03 (1g) "AMZ" means acute mixing zone concentration based on presence of a zone of initial dilution pursuant to NR 106.06 (3) (c).
Section 3 NR 106.03 (2m) is created to read:
NR 106.03 (2m) "Deficiency toxicity" means a condition where adverse effects occur to aquatic organisms because concentrations of common ions (e.g., sodium, calcium, magnesium, potassium, etc.) are too low.
Section 4 NR 106.03 (2m) note is created to read:
NR 106.03 (2m) note Changes in the concentration of ions in surrounding waters can cause organisms to expend too much energy trying to regulate the balance of water and dissolved materials in bodily fluids, and may result in death.
Section 5 NR 106.03 (5m) is created to read:
NR 106.03 (5m) "IC50" means the point estimate of the concentration of a toxic substance, wastewater effluent or other aqueous mixture that would cause a 50% reduction in a nonlethal biological measurement, such as reproduction or growth, of the exposed test organisms in a given time period.
Section 6 NR 106.03 (10) and (11) are repealed.
Section 7 NR 106.03 (13) is amended to read:
NR 106.03 (13) "TUa" or "toxic unit acute" means a value that is equal to 100 divided by the LC50 except as provided in s. NR 106.08(6)(d). Section 8 NR 106.03 (13m) is created to read:
NR 106.03 (13m) "TUc" or "toxic unit chronic" means a value that is equal to 100 divided by the IC25 or the IC50 except as provided in s. NR 106.08(6)(d). Section 9 NR 106.03 (14) is amended to read:
NR 106.03 (14) "Whole effluent toxicity" or "WET" means the aggregate toxic effect of an effluent as measured directly by a toxicity test.
Section 10 NR 106.04 (3m) is created to read:
NR 106.04 (3m) Water quality based effluent limitations may be imposed on internal waste streams before mixing with other waste streams or cooling water streams in lieu of imposing limitations at the point of discharge when imposition of limitations at the point source discharge location is impracticable or infeasible. Monitoring requirements as specified in s. NR 106.07(1) shall also be applied to the internal waste streams in these instances. Section 11 NR 106.05 (1) (c) is amended:
NR 106.05 (1) (c) If the department determines that a limitation based on an aquatic life acute or chronic secondary value should be established in a permit according to the provisions in this section, a permittee may request an alternative wet WET limit in accordance with s. NR 106.07 (7). Section 12 NR 106.05 (8) is repealed and recreated to read:
NR 106.05 (8) If representative discharge data are not available for a substance, water quality based effluent limitations may be included in a permit if, in the judgment of the department, water quality standards will be exceeded if the discharge of the substance is not limited.
Section 13 NR 106.05 (8) note is repealed.
Section 14 NR 106.06 (3) (b) is repealed and recreated to read:
NR 106.06 (3) (b) (intro) To assure compliance with par. (a), the department shall calculate the water quality based effluent limitation for a substance using the following procedures whenever the background concentration of the substance in the receiving water is less than the acute water quality criterion or secondary value: 1. A limitation shall be calculated using the following conservation of mass equation whenever sufficient site-specific data exist:
Limitation =(WQC) (Qs +(1−f)Qe) − (Qs − fQe) (Cs)
Qe
Where:
Limitation = Calculated limitation based on the acute toxicity criterion or secondary acute value (in units of mass per unit of volume).
WQC = The acute toxicity criterion appropriate for the receiving water as specified in chs. NR 102 to 105 or the secondary acute value determined according to ch. NR 105 or as referenced in sub. (1) Qs = Receiving water design flow (in units of volume per unit time) pursuant to sub. (bm)
Qe = Effluent flow (in units of volume per unit time) as specified in s. NR 106.06(4)(d) f = Fraction of the effluent flow that is withdrawn from the receiving water, and
Cs = Background concentration of the substance (in units of mass per unit volume) as specified in s. NR 106.06(4)(e). [NOTE to LRB: this is the same equation found in NR 106.06 (4) (b) (1) and formatted the same.]
2. A limitation shall be calculated equal to the final acute value or secondary value as determined in s. NR 105.05 for the respective fish and aquatic life subcategory for which the receiving water is classified. 3. The department shall use the more restrictive calculated effluent limitation derived in subds. 1. and 2., as the water quality based effluent limitation. If the background concentration of the substance in the receiving water is greater than the acute water quality criterion or secondary value for the substance, then the procedure in sub. (6) shall be used to calculate the limitation.
Section 15 NR 106.06 (3) (bm) is created to read:
NR 106.06 (3) (bm) The value of Qs of the receiving water for calculating effluent limitations in par. (a) based upon the acute fish and aquatic life criteria or secondary values developed according to ch.NR 105 shall be determined on a case-by-case basis. In no case may the Qs exceed the average minimum 1-day flow which occurs once in 10 years (1-day Q10) or if the 1-day Q10 flow data is not available, 80% of the average minimum 7-day flow which occurs once in 10 years (7-day Q10). Section 16 NR 106.06 (3) (c) (intro), 4., and 5. are amended to read:
NR 106.06 (3) (c) (intro) Except as provided in par. (d) sub. (2), water quality based effluent limitations as derived in par. (b) may exceed the final acute value or the secondary acute value within a zone of initial dilution provided that the acute toxicity criteria or secondary acute values are met within a short distance from the point of discharge. A zone of initial dilution shall only be approved if the discharger demonstrates to the department that mixing of the effluent with the receiving water in the zone of initial dilution is rapid and all the following conditions are met:
4. The acute toxicity criteria or secondary acute values must shall be met within 10% of the distance from the edge of the outfall structure to the edge of a mixing zone which may be determined in accordance with s. NR 102.05 (3). 5. The acute toxicity criteria or secondary acute values shall be met within a distance of 50 times the discharge length scale in any direction. The discharge length scale is defined as the square root of the cross-sectional area of any discharge outlet. If a multiport diffuser is used, this requirement must shall be met for each port using the appropriate discharge length scale for that port.
Section 17 NR 106.06 (3) (e) is created to read:
NR 106.06 (3) (e) The department shall use the methodology in ss. NR 106.07 (3) to (5) to express water quality based effluent limitations derived in this subsection as permit effluent limitations. Section 18 NR 106.06 (4) (f) is created to read:
NR 106.06 (4) (f) The department shall use the methodology in ss. NR 106.07 (3) to (5) to express water quality based effluent limitations derived in this subsection as permit effluent limitations. Section 19 NR 106.06 (7) is amended to read:
NR 106.06 (7) Effluent limitations may be established in a permit under this subsection based upon the acute and chronic aquatic life toxicity criteria expressed as dissolved concentrations which are determined using the procedures specified in ss. NR 105.05 (5) and 105.06 (8). Effluent limitations for metals calculated in this section shall be expressed as total recoverable in a permit. Section 20 NR 106.07 (1) (title) is created to read:
