Section 106.03. Definitions.

  The following definitions are applicable to terms used in this chapter.

(1g)  "AMZ" means acute mixing zone concentration based on presence of a zone of initial dilution under s. NR 106.06 (3) (c) .

(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.

(2)  "Biologically based design flow" means a receiving water design flow to protect fish and aquatic life for which both the duration of exposure is expressed in days and the allowable frequency of excursion is expressed in years. An example of a biologically based design flow is a 4-day 3-year design flow which corresponds to the lowest 4-day average flow that will limit excursions from any water quality criteria or secondary values to no more than once in 3 years.

(2m)  "Deficiency toxicity" means a condition that exists when adverse effects occur to aquatic organisms because concentrations of common ions are too low.

(3)  "Dynamic models" means computer simulation models which use real or derived time series data to predict a time series of observed or derived receiving water concentrations. Methods include continuous simulation, Monte Carlo simulations, or other similar statistical or deterministic techniques.

(4)  "EC 50 " means the point estimate of the concentration of a toxic substance, wastewater effluent or other aqueous mixture which causes an adverse effect including mortality to 50% of the exposed organisms in a given time period, when compared to an appropriate control.

(4g)  "Great Lakes" means the open Wisconsin waters of Lake Superior, Lake Michigan, Green Bay, and Chequamegon Bay, as well as adjoining open waters that exhibit characteristics of Lake Superior, Lake Michigan, Green Bay, and Chequamegon Bay, or in other ways are determined by the department to be equivalent to these waters.

(4r)  "Great Lakes system" means all the surface waters within the drainage basin of the Great Lakes.

(5)  "IC25" means the point estimate of the concentration of a toxic substance, wastewater effluent or other aqueous mixture that would cause a 25% reduction in a nonlethal biological measurement, such as reproduction or growth, of the exposed test organisms in a given time period.

(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.

(6)  "IWC" or "Instream waste concentration" means an estimate of the proportion of effluent to total volume of water (receiving water + effluent). The IWC is calculated according to the following equation:

(7)  "LC 50 " means the point estimate of the concentration of a toxic substance, wastewater effluent or other aqueous mixture which is lethal to 50% of the exposed organisms in a given time period, when compared to an appropriate control.

(8)  "Limit of detection" or "LOD" means the lowest concentration level that can be determined to be significantly different from a blank for that analytical test method and sample matrix.

(9)  "Limit of quantitation" or "LOQ" means the concentration of an analyte at which one can state with a degree of confidence for that analytical test method and sample matrix that an analyte is present at a specific concentration on the sample tested.

(11m)  "Same waterbody" means hydrologically connected waters of the State with similar water quality characteristics in which a pollutant can travel between in a reasonable period of time without significantly changing chemically or physically. Hydrological connections can include surface and groundwater connections.

(12)  "Toxicity test" means a test which determines the toxicity of a chemical substance, wastewater effluent or other aqueous mixture using living organisms. A toxicity test measures the degree of response of exposed test organisms to a chemical substance, wastewater effluent or other aqueous mixture.

(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) .

(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) .

(14)  "Whole effluent toxicity" or "WET" means the aggregate toxic effect of an effluent as measured directly by a toxicity test.

Cr. Register, February, 1989, No. 398 , eff. 3-1-89; r. (7), renum. (1) to (6), (8) and (9) to be (4), (7) to (9), (12) and (14) and am. (2), (4), (7) and (12), cr. (1), (5), (6), (10), (11) and (13), Register, August, 1997, No. 500 , eff. 9-1-97; CR 09-123 : r. and recr. (6) Register July 2010 No. 655 , eff. 8-1-10; CR 15-084 : cr. (4g), (4r), (11m) Register August 2016 No. 728 , eff. 9-1-16; CR 15-085 : renum. (1) to (1r), cr. (1g), (2m), (5m), r. (10), (11), am. (13), cr. (13m), am. (14) Register August 2016 No. 728 , eff. 9-1-16.

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. Microsoft Windows NT 6.1.7601 Service Pack 1 Examples of common ions are sodium, calcium, magnesium, potassium, etc. Microsoft Windows NT 6.1.7601 Service Pack 1 Q e Microsoft Windows NT 6.1.7601 Service Pack 1     IWC (as %) = 100 x --------------- Microsoft Windows NT 6.1.7601 Service Pack 1 (1 – f) Q e + Q s Microsoft Windows NT 6.1.7601 Service Pack 1 where: Microsoft Windows NT 6.1.7601 Service Pack 1 Q e = effluent flow Microsoft Windows NT 6.1.7601 Service Pack 1 f = fraction of the Q e withdrawn from the receiving water Microsoft Windows NT 6.1.7601 Service Pack 1 Q s = receiving water flow (in most cases ¼ of a low flow value, such as the Q 7,10, is used in order to allow a free zone of passage for aquatic organisms). Microsoft Windows NT 6.1.7601 Service Pack 1