if S2
A < 3.05
S2B
then compute the spooled standard deviation by the following equation:
spooled = [ 6SA2+ 6SB
2 ]0.5
____________
12
if S2
A > 3.05
S2B
respike at the last calculated MDL and process the samples through the procedure starting with par. (d).
NR 252.0365(3)(g)5.
5. Use the
Spooled as calculated in
subd. 3. to compute the final MDL according to the following equation:
MDL=2.681 (Spooled)
where 2.681 is equal to t (12, 1-a=.99)
NR 252.0365(3)(g)6.
6. The 95% confidence limits for MDL derived in
subd. 4. are computed according to the following equations derived from percentiles of the chi squared over degrees of freedom distribution.
MDLLCL=0.72 MDL
MDLUCL=1.65 MDL
where LCL and UCL are the lower and upper 95% confidence limits respectively based on 14 aliquots.
NR 252.0365(4)
(4) Reporting. The analytical method used shall be specifically identified by number or title and the MDL for each analyte expressed in the appropriate method reporting units. If the analytical method permits options which affect the method detection limit, these conditions shall be specified with the MDL value. The sample matrix used to determine the MDL shall also be identified with the MDL value. Report the mean analyte level with the MDL. If a laboratory standard or a sample that contained a known amount analyte was used for this determination, report the mean recovery and indicate if the MDL determination was iterated. If the level of the analyte in the sample matrix exceeds 10 times the MDL of the analyte in reagent water, do not report a value for the MDL.
NR 252.0365(5)
(5) Reference. Glaser, J.A., Foerst, D.L., McKee, G.D., Quave, S.A., and Budde, W.L., “Trace Analysis for Wastewaters," Environmental Science and Technology, 15, 1426 (1981).
NR 252.0365 History
History: Cr. Register, May, 2001, No. 545, eff. 6-1-01. NR 252.04
NR 252.04 Applicability of sulfide pretreatment standards. NR 252.04(1)(1) A POTW receiving wastewater from a facility subject to this chapter may require more stringent pretreatment standards for sulfide than those established by this chapter without EPA approval.
NR 252.04(2)
(2) The pretreatment standards for sulfide established by this chapter will not apply if the POTW receiving wastewater from a facility subject to this chapter certifies in writing with explanation of relevant factors considered, in accordance with the provisions of
sub. (3) that the discharge of sulfide from the facility does not interfere with the operation of the POTW. In making this determination, the POTW shall consider all relevant factors including but not limited to the following:
NR 252.04(2)(a)
(a) The presence and characteristics of other industrial wastewaters which can increase or decrease sulfide concentrations, pH, or both.
NR 252.04(2)(b)
(b) The characteristics of the sewer/interceptor collection system which either minimize or enhance opportunities for release of hydrogen sulfide gas.
NR 252.04(2)(c)
(c) The characteristics of the receiving POTW's headworks, preliminary and primary treatment systems, and sludge holding and dewatering facilities which either minimize or enhance opportunities for release of hydrogen sulfide gas.
NR 252.04(3)(a)(a) On October 13, 1983, a POTW which intends to certify that the sulfide pretreatment standard does not apply shall publish, in a local newspaper with the largest circulation, a notice that presents the findings supporting this determination consistent with
sub. (1). Allowance for public hearing of these findings shall be provided. The POTW shall identify all existing facilities to which the sulfide pretreatment standard otherwise established by this chapter would not apply.
NR 252.04(3)(b)
(b) On January 11, 1984, a POTW which intends to certify that the sulfide pretreatment standard does not apply shall file a written certification with the Regional Water Management Division Director, Environmental Protection Agency, in the appropriate regional office. This certification shall include the findings supporting this determination and the results of public comments, and public hearing if held.
NR 252.04(3)(c)
(c) On February 10, 1984, EPA shall acknowledge to the POTW receipt of any certification submitted under
pars. (a) and
(b), and shall indicate to the POTW the adequacy of the submission based upon a review of the factors set forth in
sub. (2).
NR 252.04(3)(d)
(d) Within 30 days of the date of receipt of adequate submissions under
pars. (a) to
(c), EPA shall publish a notice in the federal register identifying those facilities to which the sulfide pretreatment standards of this part do not apply.
NR 252.04(3)(e)
(e) A POTW may certify that the sulfide pretreatment standards of this chapter do not apply to a new source planning to discharge into the POTW. This certification shall be submitted prior to the commencement of discharge, and shall conform at a minimum with criteria in
sub. (2) and the general procedures and intervals of time contained in
pars. (a) to
(d).
NR 252.04(4)
(4) Applicability of sulfide pretreatment standards. NR 252.04(4)(a)(a) If, after EPA and the POTW have determined in accordance with this section that the sulfide pretreatment standards of this chapter are not applicable to specified facilities, a POTW then determines that there have been changed circumstances which justify application of the sulfide pretreatment standards, the POTW shall revoke the certification submitted under
sub. (3). Circumstances include, but not are not limited to, changes in the factors specified in
sub. (2). The POTW and EPA shall then adhere to the general procedures and time intervals contained in
sub. (3) in order to determine whether the sulfide pretreatment standards contained in this chapter are applicable.
NR 252.04(4)(b)
(b) If pursuant to
par. (a) the sulfide pretreatment standards of this chapter are applicable to a specified facility, the indirect discharger shall comply with the sulfide pretreatment standards no later than 18 months from the date of publication of the federal register notice identifying the facility.
NR 252.04(4)(c)
(c) At any time after October 13, 1983, if a POTW determines that there have been changed circumstances which include, but are not limited to, changes in the factors specified in
sub. (2), it may initiate proceedings contained in
sub. (3) to determine that the sulfide pretreatment standards of this section shall not be applicable. The POTW and EPA shall follow the procedures and time intervals contained in
sub. (3) to make this determination. A final determination that the sulfide pretreatment standards are not applicable shall be made prior to the discharge of sulfide not in accordance with the standards set forth in this chapter.
NR 252.04 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86;
cr. (4), Register, May, 2001, No. 545, eff. 6-1-01.
NR 252.05
NR 252.05 Compliance date for pretreatment standards for existing sources (PSES). Existing sources subject to PSES shall comply by November 25, 1985.
NR 252.05 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.06
NR 252.06 Monitoring requirements. Compliance with monthly average discharge limitations is required regardless of the number of samples analyzed and averaged.
NR 252.06 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.10
NR 252.10 Applicability; description of the hair pulp, chrome tan, retan-wet finishing subcategory. The provisions of this subcategory are applicable to process wastewater discharges resulting from any tannery which, either exclusively or in addition to other unhairing and tanning operation, processes raw or cured cattle or cattle-like hides into finished leather by chemically dissolving the hide hair, chrome tanning, and retan-wet finishing.
NR 252.10 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.11
NR 252.11 Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT). Except as provided in
40 CFR 125.30-
125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT):
-
See PDF for table 
NR 252.11 Note
1Within the range 6.0 to 9.0.
NR 252.11 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86;
am. Table, Register, May, 2001, No. 545, eff. 6-1-01.
NR 252.12
NR 252.12 Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT). Except as provided in
40 CFR 125.30-
125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT): The effluent limitations are those for BOD
5, TSS, oil and grease, and pH contained in
s. NR 252.11.
NR 252.12 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.13
NR 252.13 Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). Except as provided in
40 CFR 125.30-
125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT): The effluent limitations are those for total chromium contained in
s. NR 252.11.
NR 252.13 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.14
NR 252.14 New source performance standards (NSPS). Any new source subject to this subcategory shall achieve the following new source performance standards (NSPS):
-
See PDF for table NR 252.14 Note
1Within the range 6.0 to 9.0.
NR 252.14 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.15
NR 252.15 Pretreatment standards for existing sources (PSES). NR 252.15 Note
1 Not less than 7.0.
NR 252.15(2)
(2) Any existing source subject to this subcategory which processes less than 275 hides/day shall comply with
sub. (1), except that the total chromium limitations contained in
sub. (1) do not apply.
NR 252.15 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86;
am. Register, May, 2001, No. 545, eff. 6-1-01.
NR 252.16
NR 252.16 Pretreatment standards for new sources (PSNS). Except as provided in
40 CFR 403.7 and
s. NR 252.04, any new source subject to this subcategory that introduces process wastewater pollutants into a publicly owned treatment works shall comply with
40 CFR Part 403, and achieve the pretreatment standards contained in
s. NR 252.15.
NR 252.16 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.20
NR 252.20 Applicability; description of the hair save, chrome tan, retan-wet finish subcategory. The provisions of this subcategory are applicable to process wastewater discharges resulting from any tannery which processes raw or cured cattle or cattle-like hides into finished leather by hair save unhairing, chrome tanning, and retan-wet finishing.
NR 252.20 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.21
NR 252.21 Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT). Except as provided in
40 CFR 125.30-
125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT):
-
See PDF for table NR 252.21 Note
1Within the range 6.0 to 9.0.
NR 252.21 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.22
NR 252.22 Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT). Except as provided in
40 CFR 125.30-
125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT). The effluent limitations are those for BOD
5, TSS, oil and grease, and pH contained in
s. NR 252.21.
NR 252.22 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.23
NR 252.23 Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). Except as provided in
40 CFR 125.30-
125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT): The effluent limitations are those for total chromium contained in
s. NR 252.21.
NR 252.23 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.24
NR 252.24 New source performance standards (NSPS). Any new source subject to this subcategory shall achieve the following new source performance standards (NSPS):
-
See PDF for table NR 252.24 Note
1Within the range 6.0 to 9.0.
NR 252.24 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.25
NR 252.25 Pretreatment standards for existing sources (PSES). Except as provided in
s. NR 252.04 and
40 CFR 403.7 and
403.13, any existing source subject to this subcategory that introduces process wastewater pollutants into a publicly owned treatment works shall comply with
40 CFR Part 403, and achieve the following pretreatment standards:
-
See PDF for table NR 252.25 Note
1Not less than 7.0.
NR 252.25 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86;
am. Table, Register, May, 2001, No. 545, eff. 6-1-01.
NR 252.26
NR 252.26 Pretreatment standards for new sources (PSNS). Except as provided in
40 CFR 403.7 and
s. NR 252.04, any new source subject to this subcategory that introduces process wastewater pollutants into a publicly owned treatment works shall comply with
40 CFR Part 403, and achieve the pretreatment standards contained in
s. NR 252.25.
NR 252.26 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.30
NR 252.30 Applicability; description of the hair save or pulp, nonchrome tan, retan-wet finish subcategory. The provisions of this subcategory are applicable to process wastewater discharges resulting from any tannery which processes raw or cured cattle or cattle-like hides into finished leather by hair save or pulp unhairing, vegetable tanning or alum, syntans, oils and other agents for tanning, and retan-wet finishing.
NR 252.30 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.31
NR 252.31 Effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT). Except as provided in
40 CFR 125.30-
125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT):
-
See PDF for table NR 252.31 Note
1Within the range 6.0 to 9.0.
NR 252.31 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86;
am. Table, Register, May, 2001, No. 545, eff. 6-1-01.
NR 252.32
NR 252.32 Effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT). Except as provided in
40 CFR 125.30-
125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best conventional pollutant control technology (BCT). The effluent limitations are those for BOD
5, TSS, oil and grease, and pH contained in
s. NR 252.31.
NR 252.32 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.33
NR 252.33 Effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). Except as provided in
40 CFR 125.30-
125.32, any existing point source subject to this subcategory shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT). The effluent limitations are those for total chromium contained in
s. NR 252.31.
NR 252.33 History
History: Cr.
Register, October, 1986, No. 370, eff. 11-1-86.
NR 252.34
NR 252.34 New source performance standards (NSPS). Any new source subject to this subcategory shall achieve the following new source performance standards (NSPS):
-
See PDF for table NR 252.34 Note
1Within the range 6.0 to 9.0.
