Chapter NR 252

NR 252.32   Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT).

NR 252.33   Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

NR 252.34   New source performance standards (NSPS).

NR 252.35   Pretreatment standards for existing sources (PSES).

NR 252.36   Pretreatment standards for new sources (PSNS).

NR 252.40   Applicability; description of the retan-wet finish-sides subcategory.

NR 252.41   Effluent limitations representing the degree of effluent reduction attainable by the control technology currently available (BPT).

NR 252.42   Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT).

NR 252.43   Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

NR 252.44   New source performance standards (NSPS).

NR 252.45   Pretreatment standards for existing sources (PSES).

NR 252.46   Pretreatment standards for new sources (PSNS).

NR 252.50   Applicability; description of the no beamhouse subcategory.

NR 252.51   Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).

NR 252.52   Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT).

NR 252.53   Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

NR 252.54   New source performance standards (NSPS).

NR 252.55   Pretreatment standards for existing sources (PSES).

NR 252.56   Pretreatment standards for new sources (PSNS).

NR 252.60   Applicability; description of the through-the-blue subcategory.

NR 252.61   Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).

NR 252.62   Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT).

NR 252.63   Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

NR 252.64   New source performance standards (NSPS).

NR 252.65   Pretreatment standards for existing sources (PSES).

NR 252.66   Pretreatment standards for new sources (PSNS).

NR 252.70   Applicability; description of the shearing subcategory.

NR 252.71   Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).

NR 252.72   Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT).

NR 252.73   Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

NR 252.74   New source performance standards (NSPS).

NR 252.75   Pretreatment standards for existing sources (PSES).

NR 252.76   Pretreatment standards for new sources (PSNS).

NR 252.80   Applicability; description of the pigskin subcategory.

NR 252.81   Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).

NR 252.82   Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT).

NR 252.83   Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

NR 252.84   New source performance standards (NSPS).

NR 252.85   Pretreatment standards for existing sources (PSES).

NR 252.86   Pretreatment standards for new sources (PSNS).

NR 252.90   Applicability; description of the retan-wet finish-splits subcategory.

NR 252.91   Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT).

NR 252.92   Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT).

NR 252.93   Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

NR 252.94   New source performance standards (NSPS).

NR 252.95   Pretreatment standards for existing sources (PSES).

NR 252.96   Pretreatment standards for new sources (PSNS).

NR 252.99   Cross-references.

NR 252.01 NR 252.01 Purpose. The purpose of this chapter is to establish effluent limitations, standards of performance, and pretreatment standards for discharges of process wastes from the leather tanning and finishing category of point sources and its subcategories.

NR 252.01 History History: Cr. Register, October, 1986, No. 370, eff. 11-1-86.

NR 252.015 NR 252.015 Applicability. This chapter applies to any leather tanning and finishing facility which discharges or may discharge process wastewater pollutants to the waters of the state, or which introduces or may introduce process wastewater pollutants into a publicly owned treatment works.

NR 252.015 History History: Cr. Register, October, 1986, No. 370, eff. 11-1-86.

NR 252.02 NR 252.02 General definitions. In addition to the definitions set forth in 40 CFR Part 401, the following definitions apply to this chapter:

NR 252.02(1) (1) “Chrome tan” means the process of converting hide into leather using a form of chromium.

NR 252.02(2) (2) “Existing source” means any source that is not a new source.

NR 252.02(3) (3) “Hair pulp” means the removal of hair by chemical dissolution.

NR 252.02(4) (4) “Hair save” means the physical or mechanical removal of hair which has not been chemically dissolved, and either selling the hair as a by-product or disposing of it as a solid waste.

NR 252.02(5) (5) “Hide” means any animal pelt or skin as received by a tannery as raw material to be processed.

NR 252.02(6) (6) “Interference” means the discharge of sulfides in quantities which can result in human health hazards and risks to human life, and an inhibition or disruption of a POTW as defined in 40 CFR 403.3 (i).

NR 252.02(7) (7) “Monthly average” means the arithmetic average of 8 individual data points from effluent sampling and analysis during any calendar month.

NR 252.02(8) (8) “New source,” as defined for PSES and PSNS, means any building, structure, facility, or installation from which there is or may be a discharge of pollutants, the construction of which commenced after June 2, 1982.

NR 252.02(9) (9) “New source,” as defined for BPT, BAT, BCT, and NSPS, means any point source the construction of which commenced after January 6, 1983.

NR 252.02(10) (10) “Raw material” means the hides received by the tannery except for facilities covered by the retan-wet finish-sides and retan-wet finish-splits subcategories where “raw material” means the hide or split in the condition in which it is first placed into a wet process.

NR 252.02(11) (11) “Retan-wet finish” means the final processing steps performed on a tanned hide including, but not limited to, the following wet processes: retan, bleach, color, and fat liquor.

NR 252.02(12) (12) “Sulfide” means total sulfide as measured by the potassium ferricyanide titration method described in s. NR 252.035 or the modified Monier- Williams method described in s. NR 252.036.

NR 252.02(13) (13) “Vegetable tan” means the process of converting hides into leather using chemicals either derived from vegetable matter or synthesized to produce effects similar to those chemicals.

NR 252.02 History History: Cr. Register, October, 1986, No. 370, eff. 11-1-86; am. (12), Register, May, 2001, No. 545, eff 6-1-01.

NR 252.03 NR 252.03 Sulfide analytical method.

NR 252.03(1) (1) The potassium ferricyanide titration method described in s. NR 252.035 shall be used whenever practicable for the determination of sulfide in wastewaters discharged by plants operating in all subcategories except the hair save or pulp, non-chrome tan, retan-wet finish section in s. NR 252.30. In all other cases, the modified Monier-Williams method as described in s. NR 252.036 shall be used as an alternative to the potassium ferricyanide titration method for the determination of sulfide in wastewaters discharged by plants operating in all sections except s. NR 252.30.

NR 252.03(2) (2) The modified Monier-Williams method as described in s. NR 252.036 shall be used for the determination of sulfide in wastewaters discharged by plants operating in the hair save or pulp, non-chrome tan, retan-wet finish subcategory pursuant to s. NR 252.30.

NR 252.03 History History: Cr. Register, October, 1986, No. 370, eff. 11-1-86; r. and recr. Register, May, 2001, No. 545, eff. 6-1-01.

NR 252.035 NR 252.035 Potassium ferricyanide titration method. The following method is based on method SLM 4/2 described in Official Method of Analysis, Society of Leather Trades’ Chemists, Fourth Revised Edition, Redbourn, Herts., England, 1965 and is to be used for the determination of sulfide in alkaline wastewater.

NR 252.035(1) (1) Outline of method.

NR 252.035(1)(a) (a) The buffered sulfide solution is titrated with standard potassium ferricyanide solution in the presence of a ferrous dimethylglyoxime ammonia complex. The sulfide is oxidized to sulfur. Sulfite interferes and shall be precipitated with barium chloride. Thiosulfate is not titrated under the conditions of the determination.

NR 252.035(1)(b) (b) Apparatus: burrette, 10 ml.

NR 252.035(2) (2) Reagent.

NR 252.035(2)(a) (a) 0.1 Preparation of 0.02 N potassium ferricyanide; -32.925 g. per liter - this solution must be kept in the dark. Weigh to the nearest tenth of a gram 6.6 g. of analytical reagent grade potassium ferricyanide and dissolve in one liter distilled water. Store in an amber bottle in the dark. Prepare fresh each week.

NR 252.035(2)(b) (b) Standardization of ferricyanide solution: Transfer 50 ml. of solution to a 250 ml. Erlenmeyer flask. Add several crystals of potassium iodide, about one g., mix gently to dissolve, add one ml. of 6N hydrochloric acid, stopper the flask, and swirl gently. Let stand for 2 minutes, add 10 ml. of a 30% zinc sulfate solution, and titrate the mixture containing the gelatinous precipitate with standardized sodium thiosulfate or phenylarsine oxide titrant in the range of 0.025-0.050N. Add one ml. of starch indicator solution after the color has faded to a pale yellow, and continue the titration to the disappearance of the blue color. Calculate the normality of the ferricyanide solution using the equation:

Normality of Potassium Ferricyanide = (ml of  thiosulfate added) X (normality of thiosulfate)

K3 Fe(CN)6       Ml of K3 Fe(CN)6

NR 252.035(2)(c) (c) Preparation of 6M ammonium chloride buffer, pH 9.3: Dissolve 200 g. ammonium chloride in approximately 500 ml. distilled water, add 200 ml. 14M reagent grade ammonium hydroxide and make up to one liter with distilled water. The buffer may be prepared in a hood. Store in a tightly stoppered container.

NR 252.035(2)(d) (d) Preparation of 0.05M barium chloride solution: Dissolve 12-13 g. barium chloride dihydrate in one liter of distilled water.

NR 252.035(2)(e) (e) Preparation of ferrous dimethylglyoxime indicator solution: Mix 10 ml. 0.6 percent ferrous sulfate, 50 ml. one percent dimethylglyoxime in ethanol, and 0.5 ml. concentrated sulfuric acid.

NR 252.035(2)(f) (f) Preparation of stock sulfide standard, 1000 ppm: Dissolve 2.4 g. reagent grade sodium sulfide in one liter of distilled water. Store in a tightly stoppered container. Diluted working standards must be prepared fresh daily and their concentrations determined by EPA test procedure 376.1 (see 40 CFR 136.3, Table IB, parameter 66 (49 FR 43234, October 26, 1984, with correction notice at 50 FR 690, January 4, 1985)) immediately prior to use.

NR 252.035(2)(g) (g) Preparation of 10N NaOH: Dissolve 400 g. of analytical reagent grade NaOH in one liter distilled water.

NR 252.035(2)(h) (h) Sample preservation and storage: samples are to be field filtered by either gravity or pressure with coarse filter paper, such as Whatman 4 or equivalent, immediately after collection. Filtered samples must be preserved by adjustment to pH> 12 with 10N NaOH. Sample containers must be covered tightly and stored at 4 degrees C until analysis. Samples shall be analyzed within 48 hours of collection. If these procedures cannot be achieved, it is the laboratory’s responsibility to institute quality control procedures that shall provide documentation of sample integrity.

NR 252.035(3) (3) Procedure.

NR 252.035(3)(a) (a) Transfer 100 ml. of sample to be analyzed, or a suitable portion containing not more than 15 mg. sulfide supplemented to 100 ml. with distilled water, to a 250 ml. Erlenmeyer flask.