Office of Water Regulations ^
United States and Standards M/H-5521 EPA 440/1-88-016-S
Environmental Protection Industrial Tachriology Division February 1988
Agency Washington, DC 20460
Office of Water
Supplemental Final
Development
Document for
Effluent Limitations
Guidelines and
Standards for the
Leather Tanning
and Finishing
Point Source Category
-------
SUPPLEMENTAL FINAL DEVELOPMENT DOCUMENT
FOR
EFFLUENT LIMITATIONS GUIDELINES
NEW SOURCE PERFORMANCE STANDARDS
AND
PRETREATMENT STANDARDS
FOR THE
LEATHER TANNING AND FINISHING
POINT SOURCE CATEGORY
Lee M. Thomas
Administrator
William A. Whittington
Director
Office of Water Regulations and Standards
Devereaux Barnes, Director
Industrial Technology Division
Thomas P. O'Farrell, Chief
Consumer Commodities Branch
Rexford R. Gile, Jr.
Project Officer
February 1988
Industrial Technology Division
Office of Water
U.S. Environmental Protection Agency
Washington, D.C. 20460
-------
TABLE OF CONTENTS
SECTION TITLE PAGE
I Summary 1
II Introduction 3
III Sulfide Analytical Methods 7
IV Subcategory Water Use Ratio Determinations 25
V Best Practicable Control Technology Currently
Available {BPT) Limitations 39
VI New Source Performance Standards (NSPS) 45
VII Pretreatment Standards for New and Existing
Sources 51
VIII Remaining Issues 53
APPENDIX A - Potassium Ferricyanide
Titration Method A-l
APPENDIX B - Modified Monier-Williams
Method B-l
APPENDIX C - Definition and Procedure for
the Determination of the Method
Detection Limit C-l
APPENDIX D - Tanners' Council of America,
Inc. v. U.S. Environmental
Protection Agency, Settlement
Agreement D-l
i
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NUMBER
III-l
III-2
III-3
III-4
III-5
III-6
III-7
III-8
III-9
III-10
IV-1
IV-2
IV-3
IV-4
IV-5
IV-6
IV-7
TABLES
TITLE PAGE
Clear Water Precision and Accuracy Results 12
Comparison of Analytical Results - Herman
Oak Leather Co. 15
Comparison of Analytical Results - Irving
Tanning Co. 16
Comparison of Analytical Results -
A.C. Lawrence Leather Co. 17
Comparison of Analytical Results -
Midwest Tanning Co. 18
Comparison of Analytical Results - Gutman
and Co. 19
Comparison of Analytical Results - Scholze
Tannery 20
Comparison of Analytical Results - Coey
Tanning Company, Inc. 21
Comparison of Analytical Results - Filtered
and Unfiltered Samples 22
Identification of Sampled Tanneries 23
Subcategory Water Use Ratios Used in
Development of 1982 Effluent Limitations 26
Water Use Ratio Development for Subcategory
1, Hair Pulp, Chrome Tan, Retan-Wet Finish 29
Water Use Ratio Development for Subcategory
2, Hair Save, Chrome Tan, Retan-Wet Finish 30
Water Use Ratio Development for Subcategory
3, Hair Save or Pulp, Non-Chrome Tan,
Retan-Wet Finish 31
Water Use Ratio Development for Subcategory
4, Retan-Wet Finish-Sides 32
Water Use Ratio Development for Subcategory
5, No Beamhouse 33
Water Use Ratio Development for Subcategory
6, Through-the-blue 34
ii
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-8
-9
-10
-11
-12
1
2
3
4
5
6
7
8
9
-1
-2
-3
36
37
37
40
41
41
42
42
43
43
44
44
45
46
46
TABLES (Continued)
TITLE
Water Use Ratio Development for Subcategory
7, Shearling
Water Use Ratio Development for Subcategory
8, Pigskin
Water Use Ratio Development for Subcategory
9, Retan-Wet Finish-Splits
Subcategory Median Water Use Ratios
Subcategory Median Water Use Ratios for
New Sources
Subcategory 1, Hair Pulp, Chrome Tan,
Retan-Wet Finish Subcategory BPT Limitations
Subcategory 2, Hair Save, Chrome Tan,
Retan-Wet Finish Subcategory BPT Limitations
Subcategory 3, Hair Save or Pulp, Non-Chrome
Tan, Retan-Wet Finish Subcategory BPT
Limitations
Subcategory 4, Retan-Wet Finish-Sides
Subcategory BPT Limitations
Subcategory 5, No Beamhouse Subcategory BPT
Limitations
Subcategory 6, Through-the-Blue Subcategory
BPT Limitations
Subcategory 7, Shearling Subcategory BPT
Limitations
Subcategory 8, Pigskin Subcategory BPT
Limitations
Subcategory 9, Retan-Wet Finish-Splits
Subcategory BPT Limitations
Subcategory 1, Hair Pulp, Chrome Tan,
Retan-Wet Finish Subcategory NSPS
Subcategory 2, Hair Save, Chrome Tan,
Retan-Wet Finish Subcategory NSPS
Subcategory 3, Hair Save or Pulp, Non-Chrome
Tan, Retan-Wet Finish Subcategory NSPS
in
-------
TABLES (Continued)
NUMBER TITLE PAGE
1
H
>
Subcategory
Subcategory
4, Retan-Wet Finish-Sides
NSPS
47
VI-5
Subcategory
5, No Beamhouse Subcategory NSPS
47
VI-6
Subcategory
NSPS
6, Through-the-Blue Subcategory
48
r-
l
H
>
Subcategory
7/ Shearling Subcategory NSPS
48
00
1
M
>
Subcategory
8, Pigskin Subcategory NSPS
49
VI-9
Subcategory
Subcategory
9, Retan-Wet Finish-Splits
NSPS
49
iv
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FIGURES
NUMBER TITLE PAGE
III-1 Spike Recovery Versus Concentration in
Clean Water 14
B-l Equipment Assembly B-2
v
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FIGURES
NUMBER TITLE PAGE
III-l Spike Recovery Versus Concentration in
Clean Water 14
B1 Equipment Assembly B-2
vi
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SECTION I
SUMMARY
The Environmental Protection Agency (EPA or the Agency) is
amending 40 CFR Part 425 which limits effluent discharges to
waters of the United States and the introduction of pollutants
into publicly owned treatment works (POTW) by existing and new
sources engaged in leather tanning and finishing. EPA agreed to
promulgate these amendments in a settlement agreement with the
Tanners' Council of America, Inc. [Tanners' Council of America
Inc. v. U.S. Environmental Protection Agency, No. 83-1191, (4th
Cir., filed March 2, 1983), entered on December 11, 1984]. (The
Tanners' Council of America, Inc., was redesignated the Leather
Industries of America, Inc., in 1985.) The agreement settles a
dispute between the Council and EPA that was the subject of a
petition for judicial review of the final leather tanning and
finishing regulation promulgated by EPA on November 23, 1982 (47
FR 52848) as required by the Clean Water Act and the settlement
agreement in Natural Resources Defense Council, Inc. v. Train, 8
ERC 2120 (D.D.C. 1976), modified, 12 ERC 1833 (D.D.C. 1979), and
further modified by orders of the Court dated October 26, 1982,
August 3, 1983, and January 6, 1984.
These amendments include: (1) a new analytical method for the
determination of the presence of sulfide in wastewater for use in
the Hair Save or Pulp, Non-Chrome Tan, Retan-Wet Finish
Subcategory (Subcategory 3); (2) clarification of procedural
requirements for POTW to follow in determining whether sulfide
pretreatment standards are applicable; (3) revisions to certain
of the effluent limitations guidelines for "best practicable
control technology currently available" (BPT) and new source
performance standards (NSPS); (4) a change in the pH pretreatment
standard for tanneries falling under the provisions of the Hair
Save or Pulp, Non-Chrome Tan, Retan-Wet Finish Subcategory
(Subpart C of 40 CFR Part 425); and (5) clarification of the
production levels below which the chromium pretreatment standards
for existing sources (PSES) do not apply.
In addition, in the preamble to the promulgated amendments to 40
CFR Part 425, EPA clarifies its statements on median water use
ratios, changes in subcategorization, tanneries with mixed
subcategory operations, and composite samples of effluent
discharges from multiple outfalls. These issues are addressed in
Section VIII.
1
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SECTION II
INTRODUCTION
LEGAL AUTHORITY
The Environmental Protection Agency promulgated amendments to 40
CFR Part 425 under the authority of sections 301, 304(b), (c),
(e), and (g), 306(b) and (c), 307(b) and (c), 308 and 501 of the
Clean Water Act [the Federal Water Pollution Control Act
Amendments of 1972, as amended by the Clean Water Act of 1977 and
the Water Quality Act of 1987 (the "Act")]; 33 U.S.C. 1311,
1314(b), (c), (e), and (g), 1316(b) and (c), 1317(b) and (c),
1318, and 1361; 86 Stat. 816, et_ seq., Pub. L. 92-500; 91 Stat.
1567, Pub. L. 95-217, and Pub. L. 100-4. The amendments to the
regulation are also promulgated in response to the Settlement
Agreement in Tanners' Council of America, Inc. v. U.S.
Environmental Protection Agency, No. 83-1191, (4th Cir., 1984).
PRIOR REGULATIONS AND CHALLENGES
EPA promulgated a regulation on April 9, 1974, establishing
limitations guidelines and standards for the leather tanning and
finishing point source category based on the best practicable
control technology currently available ("BPT"), the best
available technology economically achievable ("BAT"),' new source
performance standards ("NSPS") for new direct dischargers, and
pretreatment standards for new indirect dischargers ("PSNS") (39
FR 12958; 40 CFR Part 425, Subparts A-F). The Tanners' Council
of America, Inc., (TCA), challenged this regulation, and the U.S.
Court of Appeals for the Fourth Circuit let BAT and NSPS
undisturbed, but remanded the BPT and NSPS limitations and
standards for several reasons [see Tanners' Council of America
Inc~ v. Train, 540 F.2d 1188 (4th Cir. 1976)].
On March 23, 1977 (42 FR 15696), EPA promulgated pretreatment
standards for existing sources ("PSES") for the leather tanning
and finishing industry. This regulation established for existing
indirect dischargers specific pH standards and other pretreatment
standards to avoid interference with POTWs. This rule was not
challenged.
EPA proposed a new regulation (44 FR 38746, July 2, 1979)
establishing, effluent limitations guidelines and standards for
the leather tanning and finishing point source category based on
revised BPT and NSPS to replace the remanded BPT and NSPS
limitations and standards, new best conventional pollutant
control technology ("BCT") limitations, and revised BAT, PSES,
and PSNS limitations and standards. EPA accepted comments on the
proposed regulation until April 10, 1980. The leather tanning
and finishing industry commented that the data and supporting
3
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record material relied upon by EPA in proposing the regulation
contained a large number of errors. The Agency responded by
completely reviewing the entire data base and all documentation
supporting the rulemaking, and by acquiring supplemental data
during and after the comment period.
On June 2, 1982 (47 FR 23958), EPA made available for public
review and comment supplementary technical and economic data and
related documentation received after proposal of the regulation.
The Agency also summarized the preliminary findings on how the
supplementary record materials might influence the final
rulemaking.
The final regulation for the leather tanning and finishing
industry point source category was promulgated on November 23,
1982 (47 FR 52848) and established effluent limitations
guidelines and standards to control specific toxic,
nonconventional, and conventional pollutants for nine
subcategories in the Leather Tanning and Finishing Category (40
CFR Part 425).
Subcategory 1
Subcategory 2
Subcategory 3 -
Subcategory 4
Subcategory 5 -
Subcategory 6
Subcategory 7
Subcategory 8
Subcategory 9
Hair Pulp, Chrome Tan, Retan-Wet Finish
Subcategory (Subpart A of 40 CFR Part
425)
Hair Save, Chrome Tan, Retan-Wet Finish
Subcategory (Subpart B of 40 CFR Part
425)
Hair Save or Pulp, Non-Chrome Tan,
Retan-Wet Finish Subcategory (Subpart C
of 40 CFR Part 425)
Retan-Wet Finish-Sides Subcategory
(Subpart D of 40 CFR Part 425)
No Beamhouse Subcategory (Subpart E of
40 CFR Part 425)
Through-the-Blue Subcategory (Subpart F
of 40 CFR Part 425)
Shearling Subcategory (Subpart G of 40
CFR Part 425)
Pigskin Subcategory (Subpart H of 40 CFR
Part 425)
Retan-Wet Finish-Splits Subcategory
(Subpart I of 40 CFR Part 425)
BPT effluent limitations guidelines were established for all
subcategories based on biological treatment, specifically high
solids extended aeration activated sludge. They include
4
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production-based effluent limitations (kg/kkg or lb/1000 lb of
raw material) for one toxic pollutant (total chromium), three
conventional pollutants (BODjj, TSS, oil and grease), and
established an acceptable pH range. BPT production-based
effluent limitations were derived using subcategory median water
use ratios, attainable effluent concentrations, and variability
factors.
BAT and BCT effluent limitations guidelines were also established
for all nine subcategories in the leather tanning and finishing
point source category. The technology basis and production-based
effluent limitations for BAT and BCT were the same as those for
the promulgated BPT effluent limitations guidelines. The BCT
effluent limitations guidelines control three conventional
pollutants (BODjj, TSS, oil and grease), and established an
acceptable pH range. The BAT effluent limitations guidelines
controlled one toxic pollutant (total chromium).
The production-based NSPS for all nine subcategories limited one
toxic pollutant (total chromium) and three conventional
pollutants (BODjj, TSS, oil and grease), and established an
acceptable pH range. NSPS were based on the same technology,
effluent concentrations, and variability factors as BAT, but the
production-based limitations for NSPS were different from those
for BAT because the NSPS limitations were based on reduced water
use ratios.
The final regulation established concentration-based categorical
pretreatment standards for existing and new source indirect
dischargers for one toxic pollutant (total chromium) for all nine
subcategories except for existing small indirect dischargers in
Subcategories 1, 3, and 9 (Subparts A, C, and I to 40 CFR Part
425 respectively).
Concentration-based categorical pretreatment standards were also
established for the control of sulfides in Subcategories 1, 2, 3,
6, and 8 (Subparts A, B, C, F, and H to 40 CFR Part 425
respectively) where unhairing operations are included. However,
the regulation included a provision which allows a POTW to
certify to the Regional Water Management Division Director of
EPA, in the appropriate Regional Office, in accordance with 40
CFR 425.04, that the discharge of sulfide from a particular
facility does not interfere with its treatment works. If this
certification is made, and EPA determines that the submission is
adequate, EPA will publish a notice in the Federal Register
identifying the facility where the sulfide pretreatment standard
would not apply.
The cost of pretreatment technology can be minimized by reducing
to the maximum extent feasible the volume of wastewater treated.
Therefore, the Agency used reduced water use ratios to calculate
the costs of PSES/PSNS technology for indirect dischargers
instead of median water use ratios.
5
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CHALLENGE TO THE 1982 REGULATION BY THE TANNERS' COUNCIL OF
AMERICA, INC.
The Tanners' Council of America, Inc. (TCA), filed a petition for
judicial review of several aspects of the final regulation in the
U.S. Circuit Court of Appeals for the Fourth Circuit on March 2,
1983 (Tanners' Council of America/ Inc. v. U.S. Environmental
Protection Agency, No. 83-1191), and followed this by filing with
EPA an administrative Petition for Reconsideration on May 9,
1983. The Agency responded by completely reviewing the entire
data base and all documentation supporting the rulemaking, and by
acquiring supplemental data. After extensive discussions, TCA
and EPA resolved the issues raised by the Council through a
settlement agreement.
SETTLEMENT AGREEMENT
On December 11, 1984, TCA and EPA entered into a comprehensive
settlement agreement which resolved all issues raised by TCA in
its petitions. In the settlement agreement, EPA agreed to
propose and promulgate amendments to the leather tanning and
finishing regulation and solicit comments regarding the proposed
amendments. In addition, EPA agreed to propose and promulgate
specific preamble language. Copies of the settlement agreement
were promptly sent to EPA Regional Offices and State NPDES
permit-issuing authorities on December 21, 1984.
If, after EPA takes final action under the settlement agreement,
each provision of the final leather tanning and finishing
industry regulation and each preamble statement is substantially
the same as that called for by the settlement agreement, TCA will
move to dismiss its petition for judicial review and voluntarily
withdraw the "Petition for Reconsideration."
In the settlement agreement, EPA agreed to propose and promulgate
preamble changes and amendments to 40 CFR Part 425 to (1) allow
the use of a new alternative sulfide analytical method, (2)
clarify the procedures to be followed by a POTW when changed
circumstances justify application of sulfide pretreatment
standards where previously waived, or a certification by a POTW
that the discharge of sulfide will not interfere with the
operation of the POTW, (3) revise effluent limitations guidelines
and standards based on corrected and more complete water use
ratio information, and (4) allow the small tannery exemption
without restriction as to the number of working days per week.
6
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SECTION III
SULFIDE ANALYTICAL METHODS
TCA CONCERNS AND EPA RESPONSE
EPA had promulgated a categorical sulfide pretreatment standard
and required all facilities to use the Society of Leather Trades'
Chemists' "Method for Sulfide Analysis SLM 4/2" in which the
sulfide solution is titrated with standard potassium ferricyanide
solution in the presence of a ferrous dimethylglyoxime ammonia
complex. TCA and some industry members conducted testing to
determine the validity of this analytical method. These test
results revealed the following problems with the SLM 4/2 method.
1. The method described in the promulgated regulation provides
for the removal of the suspended matter by rapid filtration
through either glass wool 0£ coarse filter paper. The lack
of standardization of glass wool could potentially cause
inconsistent analytical results.
2. The titrant equivalence statement, as set forth in the
promulgated regulation, will lead to confusion in the
reporting of analytical results because it expresses the
results in terms of sodium sulfide instead of sulfide upon
which the pretreatment standards are based.
3. Colored tannery wastewater, especially vegetable tanners'
wastewater, makes it difficult to detect the destruction of
the pink color at the end point. Additionally, certain
simple phenolic substances (pyrogallol and pyrocatechol),
which are model substances for the nontannins of vegetable
tanning materials, consume the ferricyanide titrant under
the prescribed SLM 4/2 conditions. These interfering
substances may yield false results.
In response to the first problem, EPA is amending the existing
approved method to delete glass wool as an alternative rapid
filtration medium. EPA is also amending the previously approved
method to specify use of coarse filter paper.
In response to the second problem, EPA is amending the SLM 4/2
method to express the results of the titrant equivalence
statement in terms of mg./liter of sulfide which is the basis for
the pretreatment standards.
In response to the third problem, EPA 'and TCA initiated a
cooperative sampling and analytical methods development program
for vegetable tanning wastewaters in November 1983 to evaluate
the SLM 4/2 procedure and a modification of the Monier-Williams
method for sulfite to allow measurement of sulfide. The SLM 4/2
7
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procedure was modified slightly to standardize analytical
procedures and to facilitate the measurement of sulfide in
tannery wastewater. The iodometric titration procedure was not
included in the evaluation program because of analytical
interferences which led to the original selection of the SLM 4/2
procedure.
As part of the evaluation, raw and pretreated wastewaters were
collected at seven tanneries, including two vegetable tannin
tanneries, for analyses by two separate laboratories. The
analytical data showed that the modified Monier-Williams method
was able to measure sulfide in vegetable tannery wastewaters when
wastewater color prevented detection of the endpoint color change
of the ferricyanide titration procedure which was based on the
SLM 4/2 procedure. The data also showed that the method produced
considerably better spike recoveries than the ferricyanide
titration procedure. The modified Monier-Williams method, thus,
is an acceptable procedure for pretreatment standard compliance
monitoring in the leather tanning industry. The ferricyanide
titration procedure will be acceptable for use in all cases in
which wastewater color does not interfere with detection of the
endpoint color change and acceptable performance is achieved. It
is not suitable for use in tannery wastewaters containing a high
level of vegetable tannins. The methodologies of the
ferricyanide titration procedure and modified Monier-Williams
procedure are described in Appendixes A and B respectively. EPA
is promulgating the modified Monier-Williams method for tanneries
with vegetable tanning wastewaters and as an alternative sulfide
analytical procedure for other tanneries.
In accordance with the settlement agreement, the Minimum
Reportable Concentration (MRC) should be determined periodically
in each of the two sulfide analytical procedures by each
participating laboratory in accordance with the procedures
specified in Methods for Chemical Analysis of Municipal and
Industrial Wastewater, EPA-600/4-82-057, July 1982, EMSL,
Cincinnati, OH 45268. The term "MRC" is not explicitly defined
in the settlement agreement or in the 1982 Methods document cited
above. Rather, the 1982 Methods document describes a procedure
known as the the Method Detection Limit (MDL) which is now also
described in Appendix B to 40 CFR Part 136, Guidelines
Establishing Test Procedures for the Analysis of Pollutants Under
the Clean Water Act~ EPA interprets MRC to be synonymous with
the MDL described in Appendix A to the 1982 Methods document and
Appendix B to 40 CFR Part 136. Therefore the MDL procedure is
used as the MRC method. The definition and procedure for the
determination of the Method Detection Limit is in Appendix C.
SUMMARY OF ANALYSIS FOR SULFIDE ANALYTICAL METHODS EVALUATION
The results obtained during the sulfide analytical methods
evaluation by the E.C. Jordan Company and the Tanners' Council of
America, Inc., are presented in Tables III-l through 111-10 and
Figure III-l. As reflected by the data, the modified Monier-
8
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Williams procedure was able to measure sulfide in vegetable
tannery wastewater when wastewater color prevented detection of
the endpoint color change of the ferricyanide titration procedure
(SLM 4/2). Further, the modified Monier-Williams method provided
more accurate measurement of sulfide concentrations than the
ferricyanide titration procedure, which yields lower
concentrations than actually present. This is because the
modified Monier-Williams method produced considerably better
spike recoveries in the 0 to 25 mg./l. range of sulfide
concentrations. The modified Monier-Williams method thus was
shown to be an acceptable procedure for pretreatment standard
compliance monitoring of Leather Tanning and Finishing Industry
wastewater. Based on the tabulated results, the use of the
modified Monier-Williams procedure may be used instead of the
ferricyanide titration method for measurement of sulfide in all
tannery wastewaters.
The results obtained by the E.C. Jordan Company laboratory during
clean water precision and accuracy trials are shown in Table III-
1 and Figure III-l. The Tanners' Council of America, Inc., did
not report clean water precision and accuracy data. As can be
seen in Table III-l and Figure III-l, the modified Monier-
Williams procedure provided considerably better spike recoveries
at sulfide concentrations in the range of 0 to 25 mg./l. than did
the ferricyanide titration procedure. The percent recoveries
decreased rapidly, however, when the spike levels exceeded
approximately 50 mg./l. The explanation for this is that the
amount of oxidant (H2O2) present in the second trap is a
limiting factor regarding the maximum amount of sulfide
recoverable by the procedure set forth in the precision and
accuracy protocol and used during the clean water portion of the
study. The maximum recoverable amount of sulfide is between 10
and 20 milligrams. Therefore, in accordance with standard EPA
procedures for other inorganic parameters, smaller sample volumes
(i.e., diluted samples) were used where sulfide concentrations
exceed 50 mg./l. This procedure was followed by the E.C. Jordan
Company laboratory during subsequent analyses. TCA used a larger
trap and 200 ml. of peroxide solution(instead of the 50 ml. used
by the E.C. Jordan Company and obtained analytical results
comparable with the E.C. Jordan Company without cutting back on
sample volume. (See Table III-3 for Irving Tanning and Table
III-4 for A.C. Lawrence.)
Tables III-2 through III-9 present data obtained by TCA and the
E.C. Jordan Company during subsequent precision and accuracy
trials using wastewater collected at seven tanneries. Table III-
10 identifies these tanneries and gives a description of the
wastewater sampled. As evidenced by Table 111-10, the sampled
tanneries employ a variety of pretreatment options. The
collected wastewater is considered a realistic presentation of
what could be expected at other U.S. tanneries. The following
comments apply to Tables III-2 through III-9.
1. The ferricyanide titration procedure was not applied to
9
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measure sulfide in wastewater samples from Hermann Oak
(Table III-2) and Scholze (Table III-7) tanneries. This was
due to masking of the endpoint of the procedure by the deep
brown color of the wastewater. The E.C. Jordan Company
laboratory observed this phenomenon previously when using
the method to analyze a wastewater containing vegetable
tannins from the A.C. Lawrence Leather Company in Hazelwood,
North Carolina.
2. Analysts from both laboratories reported difficulties in
detecting the ferricyanide titration endpoint color change,
even in the absence of vegetable tannins.
3. Comparison of results obtained using the modified Monier-
Williams procedure with those obtained using the
ferricyanide titration for chromium tanneries shows that in
eight out of nine instances the modified Monier-Williams
procedure gave a higher estimate of sulfide concentration in
unspiked samples than the ferricyanide titration. In eight
out of 11 instances the modified Monier-Williams procedure
provided better spike recoveries than the ferricyanide
titration. Inclusion of recovery data from vegetable tannin
tanneries also favors the modified Monier-Williams
procedure: 12 out 13 instances and 12 out of 15 instances,
respectively.
4. The modified Monier-Williams procedure gave lower recoveries
in wastewater from Hermann Oak Tanning Co. (Table III-2) and
Scholze Tannery (Table III-7) than in wastewater from other
tanneries. In both cases, the initial concentration of
sulfide was very low, and MnS04 had been added at
Hermann Oak to catalyze sulfide oxidation. The ferricyanide
titration procedure gave low spike recoveries in wastewater
from Midwest Tanning (Table III-5). In this instance, the
initial sulfide concentration was also low, and MnS04
had also been added to help oxidize sulfides.
5. The available data do not provide a clear explanation for
these observations. One possibility is that there may have
been a sulfide consuming substance present in each of these
samples in sufficient quantity to affect spike recoveries.
This is especially likely in the case of Hermann Oak and
Midwest Tanning where MnS04 had been added to catalyze
sulfide oxidation. It is noteworthy that this phenomenon
was observed only in wastewaters with low sulfide
concentrations.
10
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6. It has been suggested that filtration of wastewater samples
in accordance with the ferricyanide titration procedure
might reduce the measured concentration of sulfide. The
results of a modest research program utilizing the modified
Monier-Williams procedure indicate that filtration in
accordance with ferricyanide titration procedure did not
significantly affect sulfide concentrations in wastewater
from Hermann Oak and Irving Tanning Company.
11
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TABLE III-l
CLEAN WATER PRECISION AND ACCURACY RESULTS
Modified Monier-Wi 11 iams Procedure
Ferricyanide Titration Procedure
Spi ke
Concentrati on
mg/1
0
0
0
0
Sulfide
Measured
mg/1
0
0
0
0
Percent
Recovery
Spi ke
Concentration
mg/1
0
0
0
0
Sulfide
Measured
mg/1
0.16
0.16
0.16
0.16
Percent
Recovery
5.1
5.1
5.1
5.1
5.1
4.2
4.5
4.6
100
82
88
85
4.4
4.4
4.4
4.4
2.8
2.8
2.8
2.7
64
64
64
61
4.4
4.4
4.4
4.4
2.1
2.1
2.0
2.1
48
48
45
48
8.8
8.8
8.8
8.8
4.6
4.9
4.9
4.6
52
56
56
52
15
15
15
16
16
15
16
14
106
100
100
88
13
13
13
13
8.4
9.0
9.2
9.1
65
69
71
70
25
25
25
25
25
23
25
23
100
92
100
92
22
22
22
22
20
20
19
19
91
91
86
86
26
26
26
26
17
17
17
17
65
65
65
65
50
50
50
50
43
43
44
46
86
86
88
92
44
44
44
44
41
41
41
42
93
93
93
96
12
-------
TABLE III-l (continued)
CLEAN WATER PRECISION AND ACCURACY RESULTS
Modified Monier-Williams Procedure Ferricyanide Titration Procedure
Spike Sulfide Spike Sulfide
Concentration Measured Percent Concentration Measured Percent
mg/1 mg/1 Recovery mg/1 mg/1 Recovery
135
59
44
110
99
90
135
59
44
110
98
89
135
59
44
110
94
86
135
56
42
110
90
82
269
56
21
221
214
97
269
59
22
221
210
95
269
59
22
221
205
93
269
58
22
221
205
93
13
-------
FIGURE III-l
SPIKE RECOVERY VERSUS CONCENTRATION IN CLEAN WATER
100
o
A
H
z
U1
o
cc
Ui
a.
>
a.
UJ
>
o
o
UI
m
ui
*
a
w
75 -
LEGEND
o MODIFIED MONIER-WILLIAMS
A FERRICYANIDE TITRATION
50
25
I
150
1 I
200
J
50
100
250
300
SPIKE CONCENTRATION, mg/l
-------
TABLE 111-2
COMPARISON OF ANALYTICAL RESULTS - HERMANN OAK LEATHER CO.
Modified Monier-Wi11iams Procedure Ferricyanide Titration Procedure
Spike Sulfide Spike Sulfide
Concentration Measured Percent Concentration Measured Percent
mg/1 mg/1 Recovery mg/1 mg/1 Recovery
Tanners' Council Laboratory
0 0.35 --- 0 * *
~ ~
~ ~
~ *
~ *
~ ~
0 0.1 0
0 0.28 - 0
0 0.1 0
0 0.35 - 0
0 0.52 0 * *
0 0.21 0 * *
0 0.31 0
E.C. Jordan Co. Laboratory
9.3 61
9.3 61
9.3 67
9.3 72
23 65
23 70
24 71
24 67
93 42
93 48
93 50
93 47
* Unable to determine due to wastewater color interference,
15
-------
TABLE 111-3
COMPARISON OF ANALYTICAL RESULTS - IRVING TANNING COMPANY
Modified Monier-Williams Procedure Ferricyanide Titration Procedure
Spike Sulfide Spike Sulfide
Concentration Measured Percent Concentration Measured Percent
mg/1 mg/1 Recovery mg/1 mg/1 Recovery
Tanners' Council Laboratory
0 75
0 65
0 72
0 74
0 78
0 75
0 75
0 76
0 73*
0 73*
0 88 0 30**
0 66 0 29**
0 73 0 30**
0 28**
E.C. Jordan Co. Laboratory
46
46
46
46
86
81
84
86
42
42
42
42
100**
101**
97**
98**
118
118
118
118
... »
97
97
91
52
105
105
105
105
91**
89**
89**
86**
236
236
236
236
85
83
90
94
210
210
210
210
7g**
79**
78**
79**
* Analysis performed on a 50 ml sample volume.
** Analysis performed approximately 30 days after receipt of sample. Because of
a laboratory delay, precision and accuracy analyses using the ferricyanide
titration were not run until approximately 30 days after sample collection.
As expected, the sample, preserved only by pH adjustement, lost a significant
amount of volatile sulfide during this holding period. Spike recoveries were
good, however, ranging between 78 and 101 percent, and are considered suitable
for consideration with other data as part of this study. The observed loss
of sulfide emphasizes the need for prompt analysis of samples preserved by pH
adjustment alone.
16
-------
TABLE 111-4
COMPARISONS OF
ANALYTICAL RESULTS
- A.C. LAWRENCE
LEATHER CO
Modified Monier-Williams
Procedure
Ferricyanide Titration
Procedure
Spike Sulfide
Spi ke
Sul fide
Concentration Measured
Percent
Concentrati on
Measured
Percent
mg/1 mg/1
Recovery
mg/1
mg/1
Recovery
Tanners' Council
Laboratory
0 181
0
143
0 180
0
150
0 189
0
151
0 187
0
150
0 157
0
106
_
0 182
0
105
0 120
0
104
0 178
0
105
E.C. Jordan Co.
Laboratory
110
93
110
_ _ _
75
110
96
110
75
110
93
110
75
110
86
110
73
219
85
219
_ _
72
219
85
219
72
219
82
219
70
219
89
219
68
17
-------
TABLE 111-5
COMPARISON OF ANALYTICAL RESULTS - MIDWEST TANNING CO.
Modified Monier-Williams Procedure Ferricyanide Titration Procedure
Spike Sulfide Spike Sulfide
Concentration Measured Percent Concentration Measured Percent
mg/1 mg/1 Recovery mg/1 mg/1 Recovery
Tanners' Council Laboratory
0 3.3 0 0.16
0 4.2 0 0.16
0 4.1 - 0 0.16
0 3.9 0 0.16
E.C. Jordan Co. Laboratory
0 7.5 0 0.3
0 7.7 - 0 0.3
0 8.7 0 0.3
0 10.3 0 0.3
13 86 8.3 52
13 - 95 8.3 49
13 86 8.3 49
13 64 8.3 - 46
22 87 25 40
22 77 25 40
22 65 25 40
22 71 25 - 40
18
-------
TABLE 111-6
COMPARISON OF ANALYTICAL RESULTS - GUTMAN AND COMPANY
Modified Monier-
-Wil1iams
Procedure
Ferricyanide Titration Procedure
Spi ke
Sulfide
Spi ke
Sulfide
Concentration
Measured
Percent
Concentrati on
Measured
Percent
mg/1
mg/1
Recovery
mg/1
mg/1
Recovery
Tanners' Council Laboratory
0
17
_ _ _
0
15
0
21
0
16
0
20
0
15
0
21
0
14
E.C. Jordan
Laboratory
0
25
_ _ _
0
13
0
25
0
13
0
23
0
13
0
22
0
13
22
_ _ _
91
38
_ _ -
79
22
86
38
79 '
22
82
38
79
22
91
38
79
30
_ _
77
63
...
79
30
80
63
79
30
77
63
79
30
77
63
79
19
-------
TABLE 111-7
COMPARISON OF ANALYTICAL RESULTS - SCHOLZE TANNERY
Modified Monier-Williams Procedure Ferricyanide Titration Procedure
Spike Sulfide Spike Sulfide
Concentration Measured Percent Concentration Measured Percent
mg/1 mg/1 Recovery mg/1 mg/1 Recovery
Tanners' Council Laboratory
0 o 0
0 o 0
0 0 0
0 0.8 0
E.C. Jordan Laboratory
0 1.1 0
0 0.9 - 0
0 1.1 0
0 1.4 0
4.6 53
4.6 70
4.6 --- 40
4.6 51
12 60
12 92
12 » 66
12 56
* Unable to determine due to wastewater color interference.
20
-------
TABLE 111-8
COMPARISON OF ANALYTICAL RESULTS - COEY TANNING COMPANY, INC.
Modified Monier-
-Wi11i ams
Procedure
Ferricyanide Titration
Procedure
Spi ke
Sulfide
Spi ke
Sulfide
Concentrati on
Measured
Percent
Concentrati on
Measured
Percent
mg/1
mg/1
Recovery
mg/1
mg/1
Recovery
Tanners'
Council Laboratory
0
34
_ _
0
32
0
43
0
34
0
44
0
34
0
44
0
34
E.C. .
Jordan Laboratory
0
45
0
32
0
41
0
32
0
44
0
32
0
47
0
32
48
_
100
48
_ _ _
79
48
103
48
79
48
94
48
80
48
100
48
80
93
92
97
...
79
93
92
97
79
93
100
97
79
93
93
97
79
21
-------
TABLE 111-9
COMPARISON OF ANALYTICAL RESULTS
FILTERED AND UNFILTERED SAMPLES
Spike Concentration
mg/l
Hermann Oak Leather Co.
0
0
0
Sulfide Measured
mg/1
Filtered Unfiltered
0.31
0.52
0.38
0.52
0.35
0.52
0.21
0.31
Irving Tanning Co.
103
115
119
Results from
procedure.
E.C. Jordan Laboratory using modified Monier-Williams
66
73
22
-------
TABLE 111-10
IDENTIFICATION OF SAMPLED TANNERIES
Tannery
Subcategory
Wastewater Sampled
Hermann Oak Leather Co.
St. Louis, Missouri
Irving Tanning Co.
Hart!and, Maine
A.C. Lawrence Leather Co.*
South Paris, Maine
Midwest Tanning Co.
South Milwaukee, Wisconsin
Gutman and Company
Chicago, Illinois
Scholze Tannery
Chattanooga, Tennessee
Coey Tanning Company, Inc.
Wartrace, Tennessee
Total tannery effluent
following aerated equal-
ization and MnS04 addition
Total tannery effluent
following segregated
stream pretreatment
Total tannery effluent
following equalization
and FeCl3 addition
Total tannery effluent
following aerated equal-
ization and MnS04 addition
Total tannery effluent
following equalization and
pH adjustment
Total tannery effluent
following equalization and
pH adjustment
Total tannery effluent
following segregated stream
pretreatment
~Sample collected at Paris Utilities District POTW which receives the tannery
di scharge.
23
-------
-------
SECTION IV
SUBCATEGORY WATER USE RATIO DETERMINATION
During the development of the 1982 effluent limitations
guidelines and standards for the leather tanning industry, the
Agency assembled water use data for as many facilities as
possible in each of the nine leather tanning industry
subcategories. Individual facility data was normalized on a
production basis and averaged. The normalized facility means
were subsequently ranked in order of increasing value within each
subcategory. Three water use ratio values were then selected
from each array of subcategory data.
1. Median Ratio. The Agency concluded that for the purposes of
calculating production-based BPT effluent limitations
guidelines and the cost of BPT control technology, a flow
rat'io which best represented the central tendency of each
subcategory was the median value of the individual tannery
means. The median flow ratio is that value at which half of
the individual tannery means are higher and half are lower.
The median water use ratios were achieved by at least half
the tanneries in each subcategory. The dominant factor
which determined the range of water use within subcategories
was the extent to which tanneries have implemented^ water
conservation practices.
2. Reduced Ratio. In developing more stringent BAT control
technologies for existing sources, the Agency incorporated
in-plant controls to reduce water use. Since tanneries that
meet reduced water use ratios within each subcategory were
found to use the same raw materials and major groups of
subprocesses as plants which exhibited higher water use
ratios, the Agency concluded that reduced water use ratios
are achievable for all tanneries within the individual
subcategories. Therefore, the "reduced" water use ratio is
based on the median of the lower 50 percent of the tannery
water use means within each subcategory.
3. New Source Ratio. New tanneries generally have a distinct
advantage over existing tanneries in achieving, water use
reduction and conservation. By emphasizing these items in
the design of a new tannery, a tanner has more opportunity
and flexibility than does an existing tanner. Therefore, it
is reasonable that new tanneries can achieve further
reductions in water use than can existing tanneries. To
establish realistic and achievable new source flow ratios,
the median flow ratio was based on the water use means of
those tanneries that are currently meeting or bettering the
reduced flow ratio identified by the methodology described
above.
25
-------
Table IV-1 presents the subcategory water use ratios used in
calculating the 1982 effluent limitations guidelines.
TABLE IV-1
SUBCATEGORY WATER USE RATIOS USED IN DEVELOPMENT
OF 1982 EFFLUENT LIMITATIONS
Subcategory
Median Reduced
(gal/lb) (gal/lb)
New Source
(gal/lb)
1
2
3
4
5
6
7
8
9
6.5
5.8
4.9
4.8
5.8
2.1
9.4
5.0
3.0
5.4
5.0
4.8
4.6
4.0
1.4
9.4
5.0
2.5
4.3
4.9
4.2
4.5
3.8
1.4
9.4
4.1
2.5
In its challenge of the regulations, the TCA identified specific
instances in which it claimed errors had been made in
determination of tannery mean water use ratios, thus creating
subcategory water use ratios which were too low. In some cases,
TCA supplied additional data to document water use at certain
facilities. EPA conducted an extensive review of both the
existing water use ratio data base and the new data submitted by
TCA. The existing data base was examined to make sure that all
data included in the development of final subcategory water use
ratios satisfied the applicable criteria set forth in the
Development Document. These criteria are summarized below:
1. For a tannery's data to be utilized to characterize water
use, at least 80 percent of the tannery's production must be
in one subcategory, or data from each processing operation
representing a separate subcategory . must be from a
segregated and measurable wastewater stream.
2. Both production and flow values must have been reported.
3. Production data must have been reported on the basis
specified by EPA for raw material for each subcategory.
The new data were also examined to make certain that these
criteria were met. In addition, a fourth criterion was applied
to these recent data:
26
-------
4. The data must correct errors in interpretation or use of
data submitted previously during the Agency's data
collection program or during the public comment periods on
the proposed regulation and the notice of availability.
Any data submitted that covered a time period outside that
described in the fourth criterion (i.e., after promulgation) were
not considered. Changes in individual facility water use ratios
resulting from the data review are discussed in the following
paragraphs.
Subcategory li Hair Pulp, Chrome Tan, Retan-Wet Finish
(Table IV-2)
Tannery No. 432: Review of the existing data base indicated that
the water use ratio for Tannery No. 432 was based on a letter
submitted as a comment on the proposal. The value of 7.8 gal/lb
was accepted and used without production or flow data for backup.
Therefore, this tannery is dropped from the water use ratio data
base.
Tannery No. 87; Review of the existing data base revealed that
Tannery No. 87 submitted a comment letter on the Notice of
Availability which stated that its water use ratio should be
increased from 11.5 gal/lb to 12.8 gal/lb.
Although flow and production backup were provided, the change was
not made. Because all the criteria for use of the data are
satisfied, a water use ratio of 12.8 gal/lb is assigned to this
tannery and it is included in the data base.
Tanneries Nos. 60, 183, 279, 403, 413, 509: These six
subcategory 1 tanneries were dropped from the water use ratio
data base following the June 2, 1982 Notice of Availability
because they process either all or a portion of their splits on
site, and therefore were interpreted to be mixed subcategory
tanneries (subcategories 1 and 9). However, review of the
typical raw material weights for these subcategories indicated
that an error in calculation was made in arriving at the
conclusion that these were mixed subcategory tanneries. The
weight of the split as received, before shaving, trimming, and
resplitting, was used in 1982. However, the Agency should have
used the material weight placed into the first wet process.
Using this weight, more than 90 percent of raw material falls in
subcategory 1. Therefore, these tanneries satisfy the 80 percent
criterion and water use data for these six tanneries also are
included in the subcategory 1 data base.
27
-------
Tannery No~ 5500: A water use ratio of 9.2 gal/lb, based on
1979-1980 data, was assigned to this tannery for the Notice of
Availability. However, in its comment on the Notice, the tannery
presented average flow and production values for 1981 that yield
a water use ratio of 7.7 gal/lb. Following the Notice of
Availability this tannery was dropped from the water use ratio
data base because either all or a portion of its splits are
processed on-site. A review of the typical raw material weights
for these subcategories, however, indicates that an error in
calculation was made in arriving at the conclusion that this was
a mixed subcategory tannery (subcategories 1 and 9). The weight
of the split as received, before shaving, trimming, and
resplitting, was used. However, use of the split weight into wet
process reveals that more than 90 percent of raw materials falls
in subcategory 1. Therefore, this tannery satisfies the 80
percent ¦ criteria and its water use ratio of 7.7 gal/lb is
included in the subcategory 1 data base.
28
-------
TABLE IV-2
WATER USE RATIO DEVELOPMENT FOR SUBCATEGORY 1 .
HAIR PULP, CHROME TAN, RETAN-WET FINISH
November
1982 Revised
Tannery ; Value , (gal/lb) Value (gal/lb)
248 3.0 3.0
383 3.1 3.1
520 3.2 3.2
274 3.8 3.8
413 4.0*
246 4.3 4.3
525 4.5 4.5
438 5.4 5.4
245 5.4 5.4
80 5.5 5.5
237 5.7 5.7
235 6.0 6.0
60 6.0*
425 6.1 6.1
262 6.2 6.2
206 6.4 6.4
13 6.5 6.5
403 6.7*
103 6.8 6.8
431 7.0 7.0
509 7.0*
626 7.5 7.5
6 7.6 7.6
5500 7.7*
432 7.8 Dropped*
632 7.9 7.9
231 8.9 8.9
31 8.9 8.9
279 , 9.2*
183 9.2*
58 9.7 9.7
37185 9.9 9.9
57 10.5 10.5
409 10.7 10.7
87 11 . 5 12.8*
Median ratio 6.5 6.6*
Reduced ratio 5.4 5.4 ,
New source .ratio 4.3 4.3
* Changed value
29
-------
Subcategory 2; Hair Save, Chrome Tan, Retan-Wet Finish
There were no changes to the water use ratio data base for this
subcategory.
TABLE IV-3
WATER USE RATIO DEVELOPMENT FOR SUBCATEGORY 2
HAIR SAVE, CHROME TAN, RETAN-WET FINISH
November
1982 Revised
Tannery Value (gal/lb) Value (gal/lb)
7 [4.9] [4.9]
8 5.0 5.0
236 5.8 5.8
320 6.8 6.8
Median ratio 5.8 5.8
Reduced ratio 5.0 5.0
New source ratio 4.9 4.9
[ ] These values used only for new source water use ratio
development. The basis for this is discussed in the 1982
Development Document (EPA 440/1-82/016).
Subcategory 3: Hair Save or Pulp, Non-Chrome Tan, Retan-Wet
Finish (Table IV-4)
Tannery No. 404: EPA's criteria for inclusion of data from a
mixed subcategory tannery, such as Tannery No. 404, requires that
data representing each subcategory must be obtained from a
segregated and measurable wastewater stream. At the time of data
base development, documentation in a comment letter appeared to
properly addresss this issue; however, TCA included in its
petition a letter from the tannery stating that these criteria
were not in fact met. Based on these facts, this facility is
dropped from the water use ratio data base for this subcategory
and subcategory 4.
Tannery No. 239: In its comment on the Notice of Availability,
Tannery No. 239 stated that the ratio of record, 7.9 gal/lb, was
too low and should be increased to 9.6 gal/lb. Although average
1982 flow and production values of 130,000 gpd and 13,500 lbs/day
were supplied as backup, the assigned ratio was not changed.
Because all the criteria for use of the data are satisfied, an
updated water use ratio of 9.6 gal/lb is assigned to this
tannery.
30
-------
TABLE IV-4
WATER USE RATIO DEVELOPMENT FOR SUBCATEGORY 3
HAIR SAVE OR PULP, NON-CHROME TAN, RETAN-WET FINISH
November
Tannery
1982
Value (gal/lb)
Revised
Value (gal/lb)
385
415
47
397
46
186
388
399
404
239
24
376
(2.3)
(3.0)
(3.1)
4.2
4.8
4.8
4.9
4.9
7.7
7.9
8.2
9.6
(2.3)
(3.0)
(3.1)
4.2
4.8
4.8
4.9
4.9
Dropped*
9.6*
8.2
9.6
Median ratio
Reduced ratio
New source ratio
4.9
4.8
4.2
4.8*
4.5*
4.2
* Changed value
( ) Value used only for median water use ratio development. The
basis for this is discussed in the 1982 Development Document
(EPA 440/1-82/016).
Subcategory 4: Retan-Wet Finish-Sides (TABLE IV-5)
Tannery 224: Information received by EPA, in a comment letter on
the Notice of Availability, indicated that the water use ratio
assigned to Tannery 224 was based on incorrect data. This tannery
indicated that the correct ratio was 8.1 gal/lb based upon data
provided in a letter of clarification submitted as backup.
Therefore, the water use ratio for this tannery is increased from
5.6 gal/lb to 8.1 gal/lb.
Tannery No. 404: See discussion for this tannery in Subcategory
3 above.
Tannery No~ 5000; During the development of subcategory water
use ratios for the 1982 regulations, EPA assigned a water use
ratio of 4.5 gal/lb to Tannery No. 5000. Information
subsequently supplied to EPA clarified the original data and
indicated that the water use ratio at this tannery is 6.3 gal/lb.
Therefore, a water use ratio of 6.3 gal/lb is assigned to this
tannery.
31
-------
TABLE IV-5
WATER USE RATIO DEVELOPMENT FOR SUBCATEGORY 4
RETAN-WET FINISH-SIDES
Tannery
November
1982
Value (gal/lb)
Revised
Value (gal/lb)
389
404
(1.7)
(2.4)
4.6
4.9
4.5
6.4
5.6
11.4
(1.7)
Dropped*
4937
5000
625
224
191
3
4.6
4.9
6.3*
6.4
8.1
11.4
Median ratio
Reduced ratio
New source ratio
4.8
4.6
4.5
6.3*
4.8*
4.6*
* Changed value.
( ) Value used only for median water use ratio development. The
basis for this is discussed in the 1982 Development Document
(EPA 440/1-82/016).
Subcategory 5: No Beamhouse (Table IV-6)
Tannery No. 75: Review of the existing data base indicated that
the water use ratio of 5.5 gal/lb assigned to Tannery No. 75 was
based on a letter from TCA which stated that water use ranged
from 5 to 6 gal/lb. No flow or production data was provided as
backup. Review also indicates that this is a mixed subcategory
tannery (60 percent chrome tanning, 40 percent vegetable
tanning). In light of these facts, this tannery is dropped from
the water use ratio data base.
Tannery No. 169: Review of the existing data base indicated that
Tannery No. 169 is a mixed subcategory tannery (subcategories 1
and 5). In addition, raw material conversion factors used by the
tannery were not supported.by data. Therefore, this tannery is
dropped from the water use ratio data base.
Tannery No. 220; Review of the existing data base indicates that
the water use ratio of 13.5 gal/lb assigned to Tannery No. 220
was based on a letter submitted as a comment on the proposal.
That letter stated that water use was in the range of 13 to 14
gal/lb. Because no production data was provided for backup, this
tannery is dropped from the water use ratio data base.
32
-------
TABLE IV-6
WATER USE RATIO DEVELOPMENT FOR SUBCATEGORY 5
NO BEAMHOUSE
November
1982
Revised
Tannery
Value (gal/lb)
Value (gal/lb)
88
(3.5)
(3.5)
700
3.8
3.8
285
(3.8)
(3.8)
51
4.0
4.0
75
(5.5)
Dropped*
615
5.6
5.6
92
5.8
5.8
380
6.6
6.6
556
7.4
7.4
522
7.8
7.8
319 .
8.5
8.5
169
11.0
Dropped*
220
13.5
Dropped*
Median ratio
5.8
5.7*
Reduced ratio
4.0
4.0
New source ratio
3.8
3.8
* Changed value.
( ) Value used only for median water use ratio development. The
basis for this is discussed in the 1982 Development Document
(EPA 440/1-82/016}.
Subcategory 6: Through-the-Blue (Table IV-7)
Tannery No. 444; The Agency assigned a water use ratio of 1,4
gal/lb to Tannery No. 444 during the development of the 1982
regulation. Information was subsequently provided to EPA which
indicated that production and flow data available previously, but
not used because of misinterpretation, met the necessary criteria
for consideration. This additional data indicated that the water
use ratio for this tannery should be changed to 2.1 gal/lb.
Tannery No. 559: The Agency assigned a water use ratio of 1.4
gal/lb to Tannery No. 559 during the development of the 1982
regulation. Information was subsequently provided to EPA which
indicated that the water use ratio was based on winter hide
weights and thus not representative of average conditions.
Therefore, the Agency reevaluated the water use ratio reported
previously by this tannery by averaging the summer and winter
hide weights. Accordingly, the production value for this tannery
decreased and the flow ratio increased from 1.4 gal/lb to 2.3
gal/lb.
33
-------
TABLE IV-7
WATER USE RATIO DEVELOPMENT FOR SUBCATEGORY 6
THROUGH-THE-BLUE
Tannery
November
1982
Value (gal/lb)
Revised
Value (gal/lb)
444
559
502
1.4
2.1
2.6
2.1*
2.3*
2.6
Median ratio
Reduced ratio
New source ratio
2.1
1.4
1.4
2.3*
2.1*
2.1*
Changed value.
Subcategory 7: Shearling (Table IV-8)
Tannery No. 54: A review of the technical record indicates that
no usable wastewater data was available for Tannery No. 54 at the
time of the proposal or the Notice of Availability. However, in
its comment on the Notice, another tannery, of which Tannery No.
54 is an affiliate, supplied production and flow data which
indicated that Tannery No. 54's water use ratio should be 11.9
gal/lb. This data inadvertently was not added to the data base.
A water use ratio of 11.9 gal/lb is assigned to this tannery.
TABLE IV-8
WATER USE RATIO DEVELOPMENT FOR SUBCATEGORY 7
SHEARLING
Tannery
November
1982
Value (gal/lb)
Revised
Value (gal/lb)
500
54
9.4
9 . 4
11.9
Median ratio
Reduced ratio
New source ratio
9.4
9.4
9.4
10.7*
9.4
9.4
Changed value.
34
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Subcategory 8; Pigskin (Table IV-9)
Uo changes.
TABLE IV-9
WATER USE RATIO DEVELOPMENT FOR SUBCATEGORY 8
PIGSKIN
Tannery
November
1982
Value (gal/lb)
Revised
Value Cgal/lb)
185
233
(4.1)
5.8
(4.1)
5.8
Median ratio
Reduced ratio
New source ratio
5.0
5.0
4.1
5.0
5.0
4.1
{ ) Value used for median water use ratio development and new
source ratio. The basis for this was discussed in the 1982
Development Document (EPA 440/1-82/016).
Subcategory 9; Retan-Wet Finish-Splits (Table IV-10)
Tannery NO. 622: Review of the technical record indicates that
Tannery No. 622 submitted a comment letter on the Notice of
Availability containing flow and production backup which
supported a water use ratio of 4.7 gal/lb. EPA did not utilize
the data because we believed that that the backup data were
maximum design values rather than average values. When we
reviewed the comment letter and data, we realized that average
values were given. Therefore, a water use ratio of 4.7 gal/lb
is assigned to Tannery No. 622.
Tannery No. 26560; Review of the Technical Record indicates that
Tannery No. 26560 was not included in water use ratio development
for the Notice of Availability because the only information
available at that time concerning this tannery's water use was a
statement, without flow or production data, that long-term water
use was 8.3 gal/lb. In its comment on the Notice of
Availability, the tannery again stated that long-term water use
was 8.3 gal/lb, and that under recent "non-optimum conditions,"
water use had increased to 9.79 gal/lb. Flow and production
figures were provided to back up the short-term ratio of 9.79
gal/lb. The short-term ratio was not used because it was stated
to reflect "non-optimum" conditions and was significantly higher
than the long-term value. After reconsideration of the
documentation supplied by this plant, a water use ratio of 9.8
gal/lb is assigned to this tannery.
35
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TABLE IV-10
WATER USE RATIO DEVELOPMENT FOR SUBCATEGORY 9
RETAN-WET FINISH-SPLITS
Tannery
November
1982
Value (gal/lb)
Value (gal/lb)
Revised
507
97
116
622
501
(2.2)
2.5
3.4
4.9
(2.2)
2.5
3.4
4.7*
4.9
9.8*
26560
Median ratio
Reduced ratio
New source ratio
3.0
2.5
2.5
4.1*
3.0*
2.5*
* Changed value.
( ) Value used only for median water use ratio development. The
basis for this is discussed in the 1986 Development Document
(EPA 440/1-82/016).
Tables IV-11 and IV-12 summarize the revised median and new
source water use ratios respectively.
36
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TABLE IV-11
SUBCATEGORY MEDIAN WATER USE RATIOS
Number of Tanneries Median Number of Tanneries In
In Subcategory Water Use Ratio Data Base Achieving
Subcategory Data Base (gal/lb) Water Use Ratio
1
34
6.6
17
2
4
5.8
3
3
11
4.8
6
4
7
6.3
4
5
10
5.7
5
6
3
2.3
2
7
2
10.7
1
8
2
5.0
1
9
6
4.1
3
TABLE IV-12
SUBCATEGORY WATER USE RATIOS FOR NEW SOURCES
Number of Tanneries Median Number of Tanneries In
In Subcategory Water Use Ratio Data Base Achieving
Subcategory Data Base (gal/lb) Water Use Ratio
1
34
4.3
6
2
4
4.9
1
3
11
4.2
4
4
7
4.6
2
5
10
3.8
3
6
3
2.1
1
7
2
9.4
1
8
2
4.1
1
9
6
2.5
2
37
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-------
SECTION V
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
(BPT) LIMITATIONS
Revisions to the BPT effluent limitations guidelines for
subcategories 1, 3, 4, 5, 6, 1, and 9 are based on the revised
median water use ratios developed in Section IV and presented in
Table IV-11. The following methodology was used to calculate the
revised BPT effluent limitations guidelines.
The following equation was used to calculate maximum day and
monthly average production-based effluent BPT guidelines in
Tables V-l through V-9.
BPT limitations (lb/1,000 lbs raw material) = 8.34CFQ x 10-3
C = effluent concentration (mg/1)
F = variability factor
Q = subcategory median flow ratio (gal/lb raw material)
As described in the 1982 Development Document (EPA 440/1-82/016),
EPA adopted the following long-term average final effluent
concentrations ("C" in the above equation) for the leather
tanning and finishing industry.
BOD5 40 mg/1
TSS 60 mg/1
Oil and Grease 20 mg/1
Chromium (total) 1 mg/1
The following variability factors ("F" in the above equation)
were also developed by EPA in the 1982 Development Document (EPA
440/1-82/016).
where:
Maximum for
any one day
Maximum for
monthly average
BOD5
TSS
Oil and Grease
Chromium (total)
3 . 54
4 . 33
4. 21
4 .05
1 . 89
1. 85
1 . 58
1 . 59
39
-------
The revised median flow ratios ("Q" in the above equation) were
developed in Section IV and are presented in Table IV-11.
The following tables present the revised production-based
effluent BPT limitations and guidelines. BPT effluent
limitations guidelines for subcategories 2 and 8 are also
included.
TABLE V-l
Subcategory 1
Hair Pulp, Chrome Tan, Retan-Wet Finish Subcategory
BPT Limitations
BPT Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg (or pounds per 1000 lb)
of raw material
B0D5 9.3 4.2
TSS 13.4 6.1
Oil & Grease 3.9 1.7
Total Chromium 0.24 0.09
pH (1) (1)
(1) Within the range of 6.0 to 9.0.
40
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Table V-2
Subcategory 2
Hair Save, Chrome Tan, Retan-Wet Finish Subcategory
BPT Limitations
BPT Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
8.2
3.7
TSS
11.8
5.4
Oil &
Grease
3.4
1.5
Total
Chromium
0.21
0.08
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
' Table V-3
Subcategory 3
Hair Save or Pulp, Non-chrome Tan, Retan-Wet Finish Subcategory
BPT Limitations
BPT Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
6.7
3.0
TSS
9.7
4.4
Oil &
Grease
2.8
1.3
Total
Chromium
0.17
0.06
PH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
41
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Table V-4
Subcategory 4
Retan-Wet Finish-sides Subcategory
BPT Limitations
BPT Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
8.9
4.0
TSS
12.8
5.8
Oil &
Grease
3.7
1.7
Total
Chromium
0.23
0.08
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
Table V-5
Subcategory 5
No Beamhouse Subcategory BPT Limitations
BPT Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD5
8.0
3.6
TSS
11.6
5.3
Oil &
Grease
3.4
1.5'
Total
Chromium
0 . 21
0 . 08
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
42
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Table V6
Subcategory 6
Through-The-Blue Subcategory BPT Limitations
BPT Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
*
of
raw material
BOD 5
3.2
1.5
TSS
4.7
2.1
Oil &
Grease
1.4
0.61
Total
Chromium
0.08
0.03
pH
(1)
(X)
(1) Within the range of 6.0 to 9.0.
Table V-7
Subcategory 7
Shearling Subcategory BPT Limitations
BPT Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
15.0
6.8
TSS
21.7
9.9
Oil &
Grease
6.3
2.8
Total
Chromium
0. 39
0.14
PH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
43
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Table V-8
Subcategory 8
Pigskin Subcategory BPT Limitations
BPT Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
7.0
3.2
TSS
10.1
4.6
Oil &
Grease
3.0
1.3
Total
Chromium
0.18
0.07
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
Table V-9
Subcategory 9
Retan-Wet Finish-Splits Subcategory BPT Limitations
BPT Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
5.8
2.6
TSS
8.3
3.8
Oil &
Grease
2.4
1.1
Total
Chromium
0.15
0.05
PH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
44
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SECTION VI
NEW SOURCE PERFORMANCE STANDARDS
Revisions to the new source performance standards for
subcategories 4 and 6 were calculated as the product of (a) long-
term average final effluent concentrations, (b) appropriate
variability factors for each pollutant (both of these were
utilized in the development of BPT effluent limitations in
Section V), and (c) reduced water use ratios achievable by new
sources summarized in Table IV-12 using the equation presented in
Section V. Tables VI-4 and VI-6 present the revised standards.
NSPS are also included for the remaining subcategories.
Table VI-1
Subcategory 1
Hair Pulp, Chrome Tan, Retan-Wet Finish Subcategory NSPS
NSPS Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
6.0
2.7
TSS
8.7
4.0
Oil &
Grease
2.5
1.1
Total
Chromium
0.16
0.06
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
4-5
-------
TABLE VI-2
Subcategory 2
Hair Save, Chrome Tan, Retan-Wet Finish Subcategory NSPS
Pollutant or
Pollutant Property
NSPS Limitations
Maximum for
any one day
Maximum for
monthly average
B0D5
TSS
Oil & Grease
Total Chromium
pH
kg/kkg (or pounds per 1000 lb)
of raw material
6.9
9.9
2.9
0.18
(1)
3.1
4.5
1.3
0.06
(1)
(1) Within the range of 6.0 to 9.0.
Table VI-3
Subcategory 3
Hair Save or Pulp, Non-chrome Tan, Retan- Wet Finish
Subcategory NSPS
Pollutant or
Pollutant Property
NSPS Limitations
Maximum for
any one day
Maximum for
monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
5.9
2.7
TSS
8.5
3.9
Oil &
Grease
2.4
1.1
Total
Chromium
0.15
0.06
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
46
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Table VI-4
Subcategory 4
Retan-Wet Finish-Sides Subcategory NSPS
NSPS Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD5
6.5
2.9
TSS
9.3
4.3
Oil &
Grease
2.7
1.2
Total
Chromium
0.17
0.06
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
Table VI-5
Subcategory 5
No Beamhouse Subcategory NSPS
NSPS Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
5.3
2.4
TSS
7 . 7
3.5
Oil &
Grease
2.2
1.0
Total
Chromium
0.14
0.05
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
47
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Table VI-6
Subcategory 6
Through-the-Blue Subcategory NSPS
NSPS Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
3.0
1.3
TSS
4.3
1.9
Oil &
Grease
1.2
0.55
Total
Chromium
0.08
0.03
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
Table VI-7
Subcategory 7
Shearling Subcategory NSPS
NSPS Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
13.2
5.9
TSS
19.1
8.7
Oil &
Grease
5.6
2.5
Total
Chromium
0.347
0.12
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
48
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Table VI-8
Subcategory 8
Pigskin Subcategory NSPS
NSPS Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD5
5.8
2.6
TSS
8.3
3.8
Oil &
Grease
2.4
1.1
Total
Chromium
0.15
0.05
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
Table VI-9
Subcategory 9
Retan-Wet Finish-Splits Subcategory NSPS
NSPS Limitations
Pollutant or Maximum for Maximum for
Pollutant Property any one day monthly average
kg/kkg
(or
pounds per 1000 lb)
of
raw material
BOD 5
3.5
1.6
TSS
5.1
2.3
Oil &
Grease
1.5
0.66
Total
Chromium
0.09
0.03
pH
(1)
(1)
(1) Within the range of 6.0 to 9.0.
49
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-------
SECTION VII
PRETREATMENT STANDARDS FOR EXISTING AND NEW SOURCES
EPA's economic analysis for the 1982 regulation projected that
the cost of chromium pretreatment would result in the potential
closure of four to five of six small tanneries in subcategory 1;
two of three small tanneries in subcategory 3; and four to five
of nine small tanneries in subcategory 9. No less costly
chromium control technology options or less stringent chromium
standards could be identified for these facilities. Therefore,
the PSES chromium standards were not applied to small tanneries
which process less than 275 hides/day in subcategory 1, less than
350 hides/day in subcategory 3, and less than 3600 splits/day in
subcategory 9. However, small facilities in subcategories 1 and
3 were still subject to sulfide pretreatment standards, and small
facilities in subcategories 1, 3, and 9 were still required to
comply with the general pretreatment regulations contained in 40
CFR Part 403.
The Agency further defined the applicability of the exemptions by
specifying in a Federal Register notice dated June 30, 1983 (48
FR 30115) an annual weight limit based on 260 working days per
year. The Agency has reconsidered this issue and is deleting all
reference to the annual weight basis and number cf working days
per year because the weight limit penalized facilities which
operate more than five days per week and where raw material
weights do not correspond to those used by EPA to calculate the
annual weight limitation.
In addition, EPA is deleting the upper pH bound of ten contained
in the PSES Subcategory 3 (Hair Save or Pulp, Non-Chrome Tan,
Retan-Wet Finish subcategory). This upper pH limit was
originally included in the PSES for all subcategories to provide
an additional tool for POTW's to use in their efforts to control
the introduction of chromium into their collection and treatment
systems. The inclusion was based on the fact that chromium
hydroxide is amphoteric and dissolves at high pH. Placing an
upper bound on pH thus helps control the discharge of dissolved
chromium. However, because the tanneries affected by the PSES of
Subcategory 3 do not use chromium as a primary tanning agent, the
inclusion of an upper pH bound is unnecessary. The lower bound
of pH 7 will remain in effect and the tanneries will continue to
be subject to the general pretreatment regulations.
51
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-------
SECTION VIII
REMAINING ISSUES
Changes in Subcategorization
Under 40 CFR 403.6(a) of the general pretreatment regulations, an
existing industrial user or a POTW may seek written certification
from the Approval Authority as to whether the industrial user
falls within a particular subcategory of a promulgated
categorical pretreatment standard. Existing users must make the
request within 60 days after the effective date of a pretreatment
standard for a subcategory under which the user may be included
or within 60 days after the Federal Register notice announcing
the availability of the technical document for the subcategory.
New sources must request this certification prior to commencing
discharge.
Persons have inquired as to the procedures that existing leather
tanning facilities should use to seek an Agency determination if
the facility decides to change its subcategorization subsequent
to the expiration of the 60-day deadline under 40 CFR 403.6(a).
In fact, 40 CFR 403.6(a) does not preclude leather tanning and
finishing facilities from changing operations which would in turn
automatically change their subcategorization status and are
unsure which subcategory they will fall into should request
written certification from the Agency as to whether the facility
falls within a particular subcategory prior to commencing
discharges which would fall within that subcategory.
Tanneries with Mixed Subcategory Operations
The pretreatment standards for chromium are not applicable to
plants with mixed subcategory operations if the greatest part of
the plant's production is in either the Hair Pulp, Chrome Tan,
Retan-Wet Finish Subcategory (Subcategory 1), the Hair Save or
Pulp, Non-Chrome Tan, Retan-Wet Finish Subcategory (Subcategory
3), or the Retan-Wet Finish-Splits Subcategory (Subcategory 9),
and if the total plant production is less than the specified
number of hides or splits per day for the particular subcategory.
The intent of this exemption is to exclude small plants from the
chromium pretreatment standards, not to exclude processing
operations at medium or large plants.
53
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Multiple Outfalls
Most indirect discharging plants combine their process
wastewaters and discharge them all through one outfall. The
Agency has costed this approach by including costs for internal
plant piping for wastewater collection as well as contingency
costs to account for any unforeseen site specific costs.
If, however, an indirect discharging plant does not choose to
combine its process wastewaters for treatment and to discharge
them through one outfall, a composite sampling of the multiple
outfalls could be acceptable. A single composite sample for
multiple outfalls must be comprised of representative process
wastewaters from each outfall. A composite sample must be
combined in proportions determined by the ratio of process
wastewater flow in each outfall to the total flow of process
wastewaters discharged through all outfalls. If nonprocess
wastewater is combined with process wastewater or if a plant has
operations in more than one subcategory, the plant would have to
use the "combined wastestream formula" [40 CFR 403.6(e)] to make
this calculation. Flow measurements for each outfall must be
representative of the plant's operation. An analysis of the
total sample would then be compared to the applicable categorical
standard to determine compliance.
54
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Appendix A
Potassium Ferricyanide Titration Method
Source
The potassium ferricyanide titration 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.
Outline of Method
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 must be precipitated with barium
chloride. Thiosulfate is not titrated under the conditions of
the determination (Chariot, "Ann. chim, anal.", 1945, 27, 153;
Booth; "J. Soc. Leather Trades' Chemists," 1956, 40, 238).
Apparatus
Burrette, 10 ml.
Reagents
1. Preparation of 0.02N potassium ferricyanide: Weigh to
the nearest tenth of a gram 6.6 g. of analytical reagent grade
potassium ferricyanide and dissolve in 1 liter distilled water.
Store in an amber bottle in the dark. Prepare fresh each week.
2. Standardization of ferricyanide solution: Transfer 50
ml. of solution to a 250 ml. Erlenmeyer flask. Add several
crystals of potassium iodide (about 1 g.), mix gently to
dissolve, add 1 ml. of 6N hydrochloric acid, stopper the flask,
and swirl gently. Let stand for two minutes, add 10 ml. of a 30
percent 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
1 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 [K3Fe(CN)5] =
(ml of thiosulfate added) (normality of thiosulfate)
ml of K3Fe(CN)6
A1
-------
3. 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 1 liter with distilled water. The buffer should
be prepared in a hood. Store in a tightly stoppered container.
4. Preparation of 0.05M barium chloride solution: Dissolve
12-13 g. barium chloride dihydrate in 1 liter of distilled water.
5. Preparation of ferrous dimethylglyoxime indicator
solution: Mix 10 ml. 0.6 percent ferrous sulfate, 50 ml. 1
percent dimethylglyoxime in ethanol, and 0.5 ml. concentrated
sulfuric acid.
6. Preparation of stock sulfide standard, 1000 ppm:
Dissolve 2.4 g. reagent grade sodium sulfide in 1 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.
7. Preparation of 10N NaOH: Dissolve 400 g. of analytical
reagent grade NaOH in 1 liter distilled water.
Sample Preservation and Storage
Samples are to be field filtered (gravity or pressure) with
coarse filter paper (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°C until analysis. Samples must 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 will provide documentation of
sample integrity.
Procedure
1. 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.
2. Adjust the sample to pH 8.5 - 9.5 with 6N HC1.
3. Add 20 ml. of 6M ammonium chloride buffer (pH 9.3), 1
ml. of ferrous dimethylglyoxime indicator, and 25 ml. of 0.05M
barium chloride. Mix gently, stopper, and let stand for 10
minutes.
4. After 10 minutes titrate with standardized potassium
A-2
-------
ferricyanide to disappearance of pink color. The endpoint is
reached when there is no reappearance of the pink color after 30
seconds.
Calculation and Reporting of Results
1. mg./l. sulfide = A x B x 16/000
vol. in ml. of sample titrated
where A = volume in ml. of potassium ferricyanide
solution used,
and B = normality of potassium ferricyanide
solution.
2. Report results to two significant figures.
Quality Control
1. Each laboratory that uses this method is required to
operate a formal quality control program. The minimum
requirements of this program consist of an initial demonstration
of laboratory capability and the analysis of replicate and spiked
samples as a continuting check on performance. The laboratory is
required to maintain performance records to define the quality of
data that is generated. Ongoing performance checks must be
compared with established performance criteria to determine if
the results of analyses are within precision and accuracy limits
expected of the method.
2. Before performing any analyses, the analyst must
demonstrate the ability to generate acceptable precision and
accuracy with this method by performing the following operations.
(a) Perform four replicate analyses of a 20 mg./l. sulfide
standard prepared in distilled water (see paragraph 6 under
"Reagents" above).
(b)(1) Calculate clean water precision and accuracy in
accordance with standard statistical procedures. Clean wter
acceptance limits are presented in paragraph 2(b)(2) below.
These criteria must be met or exceeded before sample analyses can
be initiated. A clean water standard must be analyzed with each
sample set and the established criteria met for the analysis to
be considered under control.
(2) Clean water precision and accuracy acceptance limits:
For distilled water samples containing from 5 mg./l. to 50 mg./l.
sulfide, the mean concentration from four replicate analyses must
be within the range of 50 to 110 percent of the true value.
A-3
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3. The Method Detection Limit (MDL) should be determined
periodically by each participating laboratory in accordance with
the procedures specified in "Methods for Chemical Analysis of
Municipal and Industrial Wastewater," EPA - 660/4-82-057, July
1982, EMSL, Cincinnati, OH 45268. For the convenience of the
user, these procedures are contained in Appendix C to Part 425.
4. A minimum of one spiked and one duplicate sample must
be performed for each analytical event, or five percent spikes
and five percent duplicates when the number of samples per event
exceeds twenty. Spike levels are to be at the MDL (see paragraph
3 above for MDL samples) and at x where x is the concentration
found if in excess of the MDL. Spike recovery must be 40 to 120
percent for the analysis of a particular matrix type to be
considered valid. If a sample or matrix type provides
performance outside these acceptance limits, the analyses must be
repeated using the modified Monier-Williams procedure described
in Appendix B to this Part.
5. Report results in mg./liter. When duplicate and spiked
samples are analyzed, report all data with the sample results.
A-4
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Appendix B
Modified Monier-Williams Method
Outline of Method
Hydrogen sulfide is liberated from an acidified sample by
distillation and purging with nitrogen gas (N2). Sulfur
dioxide interference is removed by scrubbing the nitrogen gas
stream in a pH 7 buffer solution. The sulfide gas is collected
by passage through an alkaline hydrogen peroxide scrubbing
solution in which it is oxidized to sulfate. Sulfate
concentration in the scrubbing solution is determined by either
EPA gravimetric test procedure 375.3 or EPA turbidimetric test
procedure 375.4 [see 40 CFR 136.3, Table IB, parameter 65 (49 FR
43234, October 26, 1984, and correction notice at 50 FR 690,
January 4, 1985)].
Apparatus*
(See Figure 1.) * Catalogue numbers are given only to
provide a more complete description of the equipment necessary,
and do not constitute a manufacturer or vendor endorsement.
Heating mantle and control (VWR Cat. No. 33752-464)
1000 ml. distilling flask with three 24/40 joints (VWR Cat.
No. 29280-215)
Friedricks condenser with two 24/40 joints (VWR Cat. No.
23161-009)
125 ml. separatory funnel with 24/40 joint (VWR Cat. No.
30357-102)
Inlet tube with 24/40 joint (VWR Cat. No. 33057-105)
Adapter joint 24/40 to 19/38 (VWR Cat. No. 62905-26)
Adsorber head (2 required) (Thomas Cat. No. 9849-R29)
Adsorber body (2 required) (Thomas Cat. No. 9849-R32)
Laboratory vacuum pump or water aspirator
B-l
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WATER OUT
WATER IN
125 ml
SEPARATORY
FUNNEL
INLET
TUBE
-------
Reagents
1. Potassium hydroxide, 6N: Dissolve 340 g. of analytical
reagent grade KOH in 1 liter distilled water.
2. Sodium hydroxide, 6N: Dissolve 240 g. of analytical
reagent grade NaOH in 1 liter distilled water.
3. Sodium hydroxide, 0.03N: dilute 5.0 ml. of 6N NaOH to 1
liter with distilled water.
4. Hydrochloric acid., 6N-: Dilute 500 ml. of concentrated
HC1 to 1 liter with distilled water.
5. Potassium phosphate stock buffer, 0.5M: Dissolve 70 g.
of monobasic potassium phosphate in approximately 800 ml.
distilled water. Adjust pH to 7,0 + 0.1 with 6N potassium
hydroxide and dilute to 1 liter with distilled water. Stock
solution is stable for several months at 4°C.
6. Potassium phosphate buffer, 0.05M: Dilute 1 volume of
0.5M potassium phosphate stock buffer with 9 volumes of distilled
water. Solution is stable for one month at 4°C.
7. Alkaline 3% hydrogen peroxide: Dilute 1 volume of 30
percent hydrogen peroxide with 9 volumes of 0.03N NaOH. Prepare
this solution fresh each day of use.
8. Preparation of stock sulfide standard, 1000 ppm.:
Dissolve 2.4 g. reagent grade sodium sulfide in 1 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 immediately
prior to use [see 40 CFR 136.3, Table IB, parameter 66 (49 FR
43234, October *26, 1984, and correction notice at 50 FR 690,
January 4, 1985)].
Sample Preservation and Storage
Preserve unfiltered .wastewater samples immediately after
collection by adjustment to pH > 9 with 6N NaOH and addition of 2
ml. of 2N zinc acetate per liter. This amount of zinc acetate is
adequate to preserve 64 mg./l. sulfide under ideal conditions.
Sample containers must be covered tightly and stored at 4°C
until analysis. Samples must be analyzed within seven days of
collection. If these procedures cannot be achieved, it is the
laboratory's responsibility to institute quality control
procedures that will provide documentation of sample integrity.
B-3
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Procedure (See Figure 1_ for apparatus layout.)
1. Place 50 ml. of 0.05M pH 7.0 potassium phosphate buffer
in Trap No. 1.
2. Place 50 ml. of alkaline 3 percent hydrogen peroxide in
Trap No. 2.
3. Sample introduction and N2 prepurge: Gently mix
sample to be analyzed to resuspend settled material, taking care
not to aerate the sample. Transfer 400 ml. of sample, or a
suitable portion containing not more than 20 mg. sulfide diluted
to 400 ml. with distilled water, to the distillation flask.
Adjust the N2 flow so that the impingers are frothing
vigorously, but not overflowing. Vacuum may be applied at the
outlet of Trap No. 2 to assist in smooth purging. The N2
inlet tube of the distillation flask must be submerged deeply in
the sample to ensure efficient agitation. Purge the sample for
30 minutes without applying heat. Test the apparatus for leaks
during the prepurge cycle (Snoop or soap water solution).
4. Volatilization of H2S: Interrupt the N2 flow
(and vacuum) and introduce 100 ml. of 6N HC1 to the sample using
the separatory funnel. Immediately resume the gas flow (and
vacuum). Apply maximum heat with the heating mantle until the
sample begins to boil, then reduce heat and maintain gentle
boiling and N2 flow for 30 minutes. Terminate the
distillation cycle by turning off the heating mantle and
maintaining N2 flow through the system for 5 to 10 minutes.
Then turn off the N2 flow (and release vacuum) and
cautiously vent the system by placing 50 to 100 ml. of distilled
water in the separatory funnel and opening the stopcock
carefully. When the bubbling stops and the system is equalized
to atmospheric pressure, remove the separatory funnel. Extreme
care must be exercised in terminating the distillation cycle to
avoid flash-over, draw-back, or violent steam release.
5. Analysis: Analyze the contents of Trap No. 2 for
sulfate according to either EPA gravimetric test procedure 375.3
or EPA turbidimetric test procedure 375.4 [see 40 CFR 136.3,
Table IB, parameter 65 (49 FR 43234, October 26, 1984, and
correction notice at 50 FR 690, January 4, 1985)]. Use the
result to calculate mg./l. of sulfide in wastewater sample.
Calculations and Reporting of Results
1. Gravimetric procedure:
mg sulfide/1. = (mg. BaSO^ collected in Trap No. 2)x(137)
volume in ml. of waste sample distilled
B-4
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2. Turbidimetric procedure:
mg. sulfide/1. = A x B x 333
C
where A = mg./l. of sulfate in Trap No. 2
B = liquid volume in liters in Trap No. 2
and C = volume in ml. of waste sample distilled
3. Report results to two significant figures.
Quality Control
1. Each laboratory that uses this method is required to
operate a formal quality control program. The minimum
requirements of this program consist of an initial demonstration
of laboratory capability and the analysis of replicate and spiked
samples as a continuing check on performance. The laboratory is
required to maintain performance records to define the quality of
data that is generated. Ongoing performance checks must be
compared with established performance criteria to determine if
the results of analyses are within precision and accuracy limits
expected of the method.
2. Before performing any analyses, the analyst must
demonstrate the ability to generate acceptable accuracy and
precision by performing the following operations.
(a) Perform four replicate analyses of a 20 mg./l. sulfide
standard prepared in distilled water (see paragraph 8 under
"Reagents" above).
(b)(1) Calculate clean water precision and accuracy in
accordance with standard statistical procedures. Clean water
acceptance limits are presented in paragraph 2(b)(2) below.
These criteria must be met or exceeded before sample analyses can
be initiated. A clean water standard must be analyzed with each
sample set and the established criteria met for the analyses to
be considered under control.
(2) Clean water precision and accuracy acceptance limits:
For distilled water samples containing from 5 mg./l. to 50 mg./l.
sulfide, the mean concentration from four replicate analyses must
be within the range of 72 to 114 percent of the true value.
B-5
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3. The Method Detection Limit (MDL) should be determined
periodically by each participating laboratory in accordance with
the procedures specified in "Methods for Chemical Analysis for
Municipal and Industrial Wastewater," EPA-600/4-82-057, July
1982, EMSL, Cincinnati,. OH 45268. For the convenience of the
user, these procedures are contained in Appendix C to Part 425.
4. A minimum of one spiked and one duplicate sample must
be run for each analytical event, or five percent spikes and five
percent duplicates when the number of samples per event exceeds
twenty. Spike levels are to be at the MDL (see paragraph 3 above
for MDL samples) and at x when x is the concentration found if in
excess of the MDL. Spike recovery must be 60 to 120 percent for
the analysis of a particular matrix type to be considered valid.
5. Report all results in mg./liter. When duplicate and
spiked samples are analyzed, report all data with the sample
results.
B-6
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Appendix C
Definition and Procedure for the Determination
of the Method Detection Limit
The method detection limit (MDL) is defined as the minimum
concentration of a substance that can be identified, measured and
reported with 99 percent confidence that the analyte
concentration is greater than zero and determined from analysis
of a sample in a given matrix containing analyte.
Scope and Application
This procedure is designed for applicability to a wide variety of
sample types ranging from reagent (blank) water containing
analyte to wastewater containing analyte. The MDL for an
analytical procedure may vary as a function of sample type. The
procedure requires a complete, specific and well defined
analytical method. It is essential that all sample processing
steps of the analytical method be included in the determination
of the method detection limit.
The MDL obtained by this procedure is used to judge the
significance of a single measurement of a future sample.
The MDL procedure was designed for applicability to a broad
variety of physical and chemical methods. To accomplish this,
the procedure was made device- or instrument-independent.
Procedure
1. Make an estimate of the detection limit using one of the
following:
(a) The concentration value that corresponds to an
instrument signal/noise ratio in the range of 2.5 to 5.
If the criteria for qualitative identification of the
analyte is based upon pattern recognition techniques,
the least abundant signal necessary to achieve
identification must be considered in making the
estimate.
(b) The concentration value that corresponds to three times
the standard deviation of replicate instrumental
measurements for the analyte in reagent water.
(c) The concentration value that corresponds to the region
of the standard curve where there is a significant
change in sensitivity at low analyte concentrations,
i.e., a break in the slope of the standard curve.
(d) The concentration value that corresponds to known
instrumental limitations.
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It is recognized that the experience of the analyst is
important to this process. However, the analyst must
include the above considerations in the estimate of the
detection limit.
2. Prepare reagent (blank) water that is as free of an layte as
possible. Reagent or interference free water is defined as
a water sample in which analyte and interferent
concentrations are not detected at the method detection
limit of each analyte of interest. Interferences are
defined as systematic errors in the measured analytical
signal of an established procedure caused by the presence of
interfering species (interferent). The interferent
concentration is presupposed to be normally distributed in
representative samples of a given matrix.
3. (a) If the MDL is to be determined in reagent water
(blank), prepare a laboratory standard (analyte in
reagent water) at a concentration which is at least
equal to or in the same concentration range as the
estimated MDL. (Recommend between 1 and 5 times the
estimated MDL.) Proceed to Step 4.
(b) If the MDL is to be determined in another sample
matrix, analyze the sample. If the measured level of
the analyte is in the recommended range of one to five
times the estimated MDL, proceed to Step 4.
If the measured concentration of analyte is less than
the estimated MDL, add a known amount of anlayte to
bring the concentration of anlayte to between one and
five times the MDL. In the case where an interference
is coanalyzed with the analyte:
If ttfe measured level of anlayte is greater than five
times the estimated MDL, there are two options:
(1) Obtain another sample of lower level of analyte in
same matrix if possible.
(2) The sample may be used as is for determining the
MDL if the analyte level does not exceed 10 times
the MDL of the analyte in reagent water. The
variance of the anlaytical method changes as the
analyte concentration increases from the MDL,
hence the MDL determined under these circumstances
may not truly reflect method variance at lower
analyte concentrations.
C-2
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4. (a) Take a minimum of seven aliquots of the sample to
be used to calculate the MDL and process each
through the entire anlaytical method Make all
computations according to the defined method with
final results in the method reporting units. If
blank measurements are required to calculate the
measured level of analyte, obtain separate blank
measurements for each sample aliquot anlayzed.
The average blank measurement is subtracted from
the respective sample measurements.
(b) It may be economically and technically desirable
to evaluate the estimated MDL before proceeding
with 4a. This will: (1) prevent repeating this
entire procedure when the costs of analyses are
high and (2) insure that the procedure is being
conducted at the correct concentrtion. It is
quite possible that an incorrect MDL can be
calculated from data obtained at many times the
real MDL even though the background concentration
of analyte is less than five times the calculated
MDL. To insure that the estimate of the MDL is a
good estimate, it is necessary to determine that a
lower concentration of analyte will not result in
a significantly lower MDL. Take two aliquots of
the sample to be used to calculate the MDL and
process each through the entire method, including
blank measurements as described above in 4a.
Evaluate these data:
(1) If these measurements indicate the sample is
in the desirable range for determining the
MDL, take five additional aliquots and
proceed. Use all seven measurements to
calculate the MDL.
(2) If these measurements indicate the sample is
not in the correct range, reestimate the MDL,
obtain new sample as in 3 and repeat either
4a or 4b.
5. Calculate the variance (S2) and standard deviation
(S) of the replicate measurements, as follows:
S = (S2)0'5
C-3
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where: the x^, i = 1 to n are the analytical
results in the final method reporting units obtained
from the n sample aliquots and
n
refers to the sum of the X values from i = 1 to n.
6. (a) Compute the MDL as follows:
MDL = t(n_lf i-a = .99)(S)
where:
MDL = the method detection
fc(n-l, 1-a = .99) = the students' t value
appropriate for a 99
percent confidence level
and a standard deviation
estimate with n-1 degrees
of freedom. See Table.
S = standard deviation of the replicate analyses.
(b) The 95 percent confidence limits for the MDL
derived in 6a are computed according to the
following equations derived from percentiles
of the chi square over degrees of freedom
distribution (X2/df) and calculated as
follows:
MDLlcl = 0.69 MDL
MdLucl = 1-92 MDL
where MDLlcl and MDLycL are the lower
and upper 95 percent confidence limits
respectively based on seven aliquots.
7. Optional iterative procedure to verify the
reasonableness of the estimated MDL and calculated MDL
of subsequent MDL determinations.
(a) If this is the initial attempt to compute MDL
based on the estimated MDL in Step 1, take the MDL
as calculated in Step 6, spike in the matrix at
the calculated MDL and proceed through the
procedure starting with Step 4.
C-4
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(b) If the current MDL determination is an iteration
of the MDL procedure for which the spiking level
does not permit qualitative identification, report
the MDL as that concentration between the current
spike level and the previous spike level which
allows qualitative identification.
¦(c) If the current MDL determination is an iteration
of the MDL procedure and the spiking level allows
qualitative identification, use S2 from the
current MDL calculation and S from the
previous MDL calculation to compute the F ratio.
f SA
if ~ < 3.05
SB
then compute the pooled standard deviation by the
following equation:
rf.c2 j. tc21 0,5
s .| A + 6Sb|
pooled I 12 I
if SA
1£ > 3.05
SB
respike at the last calculated MDL and process the
samples through the procedure starting with Step
4.
(d) Use the Sp00ied as calculated in 7b to compute
the final MDL according to the following equation:
MDL = 2.681 (Spooled)
where 2.681 is equal to t(i2, 1-a = .99)
(e) The 95 percent confidence limits for MDL derived
in 7c are computed according to the following
equations derived from percentiles of the chi
squared over degrees of freedom distribution.
mdlLCL = °-72 MDL
MDLucL = i-65 MDL
where LCL and UCL are the lower, and upper 95
percent confidence limits respectively based on 14
aliquots.
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Reporting
The analytical method used must 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 must be specified with the MDL value. The sample
matrix used to determine the MDL must 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.
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)
Table of Students' t Values at the 99 Percent Confidence Level
Number of Degrees of Freedom
Replicates (n-1) fc(n-l, 1-a = .99)
7
8
9
10
11
16
21
26
31
61
6
7
8
9
10
15
20
25
30
60
3.143
2.998
2.896
2.821
2.764
2.602
2.528
2.485
2.457
2.390
2.326
C-6
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UNITED STATES COURT OF APPEALS
FOR THE FOURTH CIRCUIT
)
TANNERS'COUNCIL OF AMERICA, INC., )
)
Petitioner, )
) No. 83-1191
v. )
)
U.S. ENVIRONMENTAL PROTECTION AGENCY, )
)
Respondent. )
)
SETTLEMENT AGREEMENT
Petitioner Tanners' Council of America, Inc. ("TCA") and respondent U.S.
Environmental Protection Agency ("EPA" or "the Agency"), intending to be bound by this
agreement, hereby stipulate and agree as follows:
1. The parties agree that, except as provided herein, this agreement
resolves all challenges which were or could have been raised with respect to the Clean
Water Act regulations establishing effluent limitations guidelines and standards for the
leather tanning and finishing industry point source category ("leather tanning
regulations"), published at 47 Fed. Reg. 52,848 (November 23, 1982).
2. EPA agrees to propose and take final action on the amendments to
the leather tanning regulations set forth in Exhibit A to this agreement and the
accompanying preamble language set forth in Exhibit B to this agreement in accordance
with the following schedule:
(a) Immediately after the execution of this Settlement
Agreement, EPA shall notify the state directors of
approved permitting agencies and the EPA Regional
Administrators of this agreement and provide them with
copies.
D-l
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- 2 -
(b) As expeditiously as possible, EPA shall submit the
proposed amendments and preamble language (Exhibits
A and B) to the Office of Management and Budget
("OMB") in accordance with the terms of Executive
Order 12291. EPA shall request that OMB expeditiously
review the proposed amendments and preamble
language.
(c) As expeditiously as possible after the completion of
OMB review, EPA shall submit the proposed amend-
ments and preamble language to the Federal Register
for immediate publication.
(d) The public comment period on the proposed amendments
and preamble language shall be no longer than 30 days.
EPA may extend this period for a maximum of 30 days
if it receives a request for an extension based upon
compelling circumstances not apparent at the time of
execution of this agreement. If EPA extends the com-
ment period, it shall immediately notify TCA of the
cause or causes for the extension and the additional
time allowed for comment. No extension shall exceed
"the time required by its cause.
(e) As expeditiously as possible after the close of the public
comment period on the. proposed amendments and pre-
amble language, EPA shall submit any final amendments
and preamble language to OMB in accordance with the
terms of Executive Order 12291. EPA shall request that
OMB expeditiously review these amendments and pre-
amble language.
(f) As expeditiously as possible after the completion of
OMB review, EPA shall submit any final amendments
and preamble language to the Federal Register for
immediate publication. Unless . compelling circum-
stances arise not apparent on the date of execution of
this agreement, EPA shall set the effective date of the
final regulations no later than 44 days after publication
in the Federal Register.
3. The parties agree that if, after EPA has taken final action under this
agreement, any individual provision of the final leather tanning regulations or any
p:ct.r.ible section is not substantially the same as or alters the meaning of the language
set forth in Exhibits A and B, TCA reserves the right to proceed further with this
litigation or file a new petition for judicial review with respect to: (a) any issue related
D-2
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- 3 -
to that individual provision, and (b) all issues in the TCA Petition for Reconsideration
filed before the Administrator on May 9, 1983, entitled "In Re Leather Tanning and
Finishing Industry Effluent Limitations Guidelines, Pretreatment Standards and New
Source Performance Standards" that are not addressed in Exhibits A and B, including
issues numbered 6 (pretreatment pH lower limit), 7 (alkalinity pH pretreatment
standard), 11 (pretreatment for chromium), 13 (variability factors) and 14 (PSES mass
limitations), except that TCA may only challenge issues numbered 6 and 7 if EPA fails to
amend the pH limitation in 40 C.F.R. § 425.35(a) as set forth in Exhibit A. EPA reserves
the right to oppose such litigation on any grounds other than petitioner's execution of this
agreement. TCA reserves the right to pursue such litigation on any grounds.
4. The parties agree that within 15 days after final EPA action under
this agreement, with respect to each amendment and each preamble section which is
substantially the same as and does not alter the meaning of the language set forth in
Exhibits A and B to the agreement, TCA will voluntarily move to dismiss its petition for
review and voluntarily withdraw the Petition for Reconsideration. EPA will support this
TCA motion and neither party will seek to recover any litigation costs or fees from the
other.
5. TCA will not seek judicial review of any amendment to the leather
tanning and finishing regulations or preamble which is substantially the same as and does
not alter the meaning of the language set forth in Exhibits A and B of this agreement.
6. The parties agree that, after the effective date of this Settlement
Agreement, they will treat each amendment and preamble provision contained in Exhibits
A and B as a duly promulgated rule or interpretation until the Agency takes final action
on each proposed revision.
7. The parties agree to seek a stay of the portions of the leather tanning
regulations that EPA has agreed to propose to amend. The parties will request that this
D-3
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-4 -
stay remain in effect until the Agency completes final action on the amendments and
preamble language.
8. If for any reason the provisions of paragraphs 6 cr 7 are not
implemented by any federal or state regulating authority, TCA may seek relief in any
appropriate forum.
9. TCA agrees to submit comments in support of all amendments and
preamble language proposed in accordance with Exhibits A and B.
10. EPA agrees not to attempt to invoke this agreement as a bar in
subsequent EPA administrative proceedings (other than the proceeding contemplated by
this agreement) to revise or supplement limitations and standards addressed by the
leather tanning regulations.
11. Although EPA commits itself to take the necessary implementing
steps described in paragraph 2(a) immediately, this agreement shall not become effective
until 14 days after it has been signed by both parties.
12. TCA is a national trade association representing the leather tanning
and finishing industry. The undersigned attorney for TCA hereby certifies that he is
authorized to enter into this agreement on behalf of TCA. TCA has notified all its
members subject to the leather tanning regulations (those entities listed in Exhibit C to
this agreement) of the terms of this agreement, aEnd has requested that any member
objecting to the terms of the agreement notify TCA immediately. None of these
members has notified TCA of any objection to the terms of this agreement. Moreover,
TCA has notified these members that EPA would not enter into this agreement unless
TCA assured the Agency that the regulated members of TCA: (a) would treat the
amendments and preamble provisions contained in Exhibits A and B as duly promulgated
rules or interpretations after the execution of this Settlement Agreement; (b) would not
petition for review of any amendment or preamble provision of the leather tanning
D-4
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-5 -
regulations promulgated consistent with Exhibits A and B; and (c) would not submit
adverse comments on any proposed amendment or preamble provision to the leather
tanning regulations substantially the same as or not altering the meaning of the language
in Exhibits A and B. Based upon the responses, TCA has given EPA its reasonable
assurance that its members will act in accordance with items (a) through (c) of this
paragraph. EPA has entered into this agreement in reliance upon TCA's action and
assurances.
13. Upon execution of this agreement, the parties agree to move
promptly for a stay of this litigation pending final action by the Agency under this
agreement.
14. Nothing in this agreement shall operate to waive any legal right of
either party unless such a waiver is expressly provided.
15. The pending applications for variances based on "fundamentally
different factors" submitted by Ocean Leather Corporation, Richard Leather Company,
Carr Leather Company, Badger State Tanning Corp., and Blackhawk Tanning Company,
shall be unaffected by this Settlement Agreement.
D-5
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-6 -
16. This Settlement Agreement, Including Exhibits A, B and C, represents
the entire agreement between the Agency and TCA with respect to the leather tanning
regulations published at 47 Fed. Reg. 52,848.
Respectfully submitted,
Dated:
Richard E. Scjuf&rtz
Donald J. Patterson, Jr.
COLLIER, SHANNON, RILL &: SCOTT
1055 Thomas Jefferson Street, N.W.
Washington, D.C. 20007
202-342-8400
Attorneys for the
Tanners' Council of America, Inc.
Dated:
Jl
Lsl
In.
J
ijual T) ¦
uzxLzso
Susan M. Schmedes, Esq.
Office of General Counsel
U.S. ENVIRONMENTAL PROTECTION AGENCY
401 M Street, S.W.
Room 541, West Tower
Washington, D.C. 20460
Dated: Wt/JxH
Lee R. Tyner; Esq.
Environmental Defense Section
Land and Natural Resources Division
U.S. DEPARTMENT OF JUSTICE
Room 4436, New Post Office Building
12th & Pennsylvania Avenue, N.W,
Washington, D.C. 20530
Attorneys for the U.S.
Environmental Protection Agency
D-6
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EXHIBIT A
AMENDMENTS TO 40 C.F.R. PART 425
L SULFIDE ANALYTICAL METHODS.
Amend 40 C.F.R. § 425.02(a) to read:
"Sulfide" shall mean total sulfide as measured by the potassium ferricyanide
titration method or the modified Monier-Williams method described in § 425.03.
Amend 40 C.F.R. § 425.03 to read:
§ 425.03 Sulfide analytical methods.
(a) Applicability.
The potassium ferricyanide titration method described in § 425.03(b) 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 subcategory (Subpart C, see § 425.30). In all other cases, the modified Monier-
Williams method as described in § 425.03(c) 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 subcategories except Subpart C.
The modified Monier-Williams method as described in § 425.03(c) 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 (Subpart C, see §
425.30).
(b) Potassium Ferricyanide Titration Method.
The potassium ferricyanide titration method is based on method SLM 4/2
desc-ibed in Official Method of Analysis, Society of Leather Trades' Chemists, Fourth
Revised Edition, Redbourn, Herts., England, 1965.
D-7
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- 2 -
(1) Outline of Method. 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 must be precipitated
with barium chloride. Thiosulfate is not titrated under the conditions of the
determination. (Chariot, Ann, chim, anal., 1945, 27, 153; Booth, J. Soc. Leather Trades'
Chemists, 1956, 40, 238).
(2) Apparatus. Burrette, 10 ml.
(3) Reagents.
(A) Preparation of 0.02N potassium ferricyanide: Weigh to the nearest
tenth of a gram 6.6 g of analytical reagent grade potassium
ferricyanide and dissolve in 1 liter distilled water. Store in an
amber bottle in the dark. Prepare fresh each week.
(B) Standardization of ferricyanide solution: Transfer 50 ml of solution
to a 250 ml Erlenmeyer flask. Add several crystals of potassium
iodide (about 1 g), mix gently to dissolve, add 1 ml of 6N
hydrochloric acid, stopper the flask, and swirl gently. Let stand for
two minutes, add 10 ml of a 30 percent 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 1 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 (KjFe(CN)g) =
(ml of thiosulfate added) (normality of thiosulfate)
ml of K3Fe(CN)6
D-8
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- 3 -
(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 1
liter with distilled water. The buffer should be prepared in a hood.
Store in a tightly stoppered container.
(D) Preparation of 0.05 M barium chloride solution: Dissolve 12-13 g
barium chloride dihydrate in 1 liter of distilled water.
(E) Preparation of ferrous dimethylglyoxime indicator solution: Mix 10
ml 0.6 percent ferrous sulfate, 50 ml 1 percent dimethylglyoxime in
ethanol, and 0.5 ml concentrated sulfuric acid.
(F) Preparation of stock sulfide standard, 1000 ppm: Dissolve 2.4 g
reagent grade sodium sulfide in 1 liter of distilled water. Store in a
tightly stoppered container. Diluted working standards must be
prepared fresh daily and their concentrations determined by EPA
376.1 immediately prior to use.
(G) Preparation of 10N NaOH: Dissolve 400 g of analytical reagent
grade NaOH in 1 liter distilled water.
(4) Sample Preservation and Storage.
Samples are to be field filtered (gravity or pressure) with coarse filter paper
(Whatman 4 or equivalent) immediately after collection. Filtered samples must be
preserved by adjustment to pHs, 12 with 10N NaOH. Sample containers must be covered
tightly and stored at 4°C until analysis. Samples must 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 will provide documentation of sample integrity.
D-9
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- 4 -
(5) Procedure.
(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.
(B) Adjust the sample to pH 8.5-9.5 with 6N HC1.
(C) Add 20 ml of 6M ammonium chloride buffer (pH 9.3), 1 ml of ferrous
dimethylglyoxime indicator, and 25 ml of 0.05 M barium chloride.
Mix gently, stopper, and let stand for 10 minutes.
(D) After 10 minutes titrate with standardized potassium ferricyanide to
disappearance of pink color. The endpoint is reached when there is
no reappearance of the pink color after 30 seconds.
(6) Calculation and Reporting of Results.
(A) mg/1 Sulfide = A x B x 16,000
voL in ml of sample titrated
where A = volume in ml of potassium ferricyanide solution used
and B = normality of potassium ferricyanide solution.
(B) Report results to two significant figures.
(?) Quality Control.
(A) Each laboratory that uses this method is required to operate a
formal quality control program. The minimum requirements of this
program consist of an initial demonstration of laboratory capability
and the analysis of replicate and spiked samples as a continuing
check on performance. The laboratory is required to maintain
performance records to define the quality of data that is
generated. Ongoing performance checks must be compared with
established performance criteria to determine if the results of
D-10
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- 5 -
analyses are within precision and accuracy limits expected of the
method.
(B) Before performing any analyses, the analyst must demonstrate the
ability to generate acceptable precision and accuracy with this
method by performing the following operations.
(i) Perform four replicate analyses of a 20 mg/1 sulfide standard
prepared in distilled water (see (3)(F)).
(ii) Calculate clean water precision and accuracy in accordance
with standard statistical procedures. Clean water acceptance
limits are presented below. These criteria must be met or
exceeded before sample analyses can be initiated. A clean
water standard must be analyzed with each sample set and
the established criteria met for the analysis to be considered
under control.
Clean water precision and accuracy acceptance limits:
For distilled water samples containing from 5 mg/1 to 50
mg/1 sulfide, the mean concentration from four replicate
analyses must be within the range of 50 to 110 percent of the
true value.
(C) The Minimum Reportable Concentration (MRC) should be
determined periodically by each participating laboratory in
accordance with the procedures specified in Methods for Organic
Chemical Analysis of Municipal and Industrial Wastewater - EPA-
600/4-82-057, July 1982, EMSL, Cincinnati, OH 45268.
(D) A minimum of one spiked and one duplicate sample must be
performed for each analytical event, or five percent spikes and five
D-ll
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- 6 -
percent duplicates when the number of samples per event exceeds
twenty. Spike levels are to be at the MRC (see (7)(C)) for MRC
samples, and at x where x is the concentration found if in excess of
the MRC. Spike recovery must be 40 to 120 percent for the analysis
of a particular matrix type to be considered valid. If a sample or
matrix type provides performance outside these acceptance limits,
the analyses must be repeated using the modified Monier-Williams
procedure described in § 425.03(c).
(E) Report results in mg/liter. When duplicate and spiked samples are
analyzed, report all data with the sample results.
(c) Modified Monier-Williams Method.
(1) Outline of Method.
Hydrogen sulfide is liberated from an acidified sample by distillation and
purging with nitrogen gas (N2). Sulfur dioxide interference is removed by scrubbing the
nitrogen gas stream in a pH 7 buffer solution. The sulfide gas is collected by passage
through an alkaline hydrogen peroxide scrubbing solution in which it is oxidized to
sulfate. Sulfate concentration in the scrubbing solution is determined by either
gravimetric (EPA 375.3) or turbidimetric (EPA 375.4) procedures.
(2) Apparatus*. (See Figure 1) *Catalogue numbers are given only to
provide a more complete description of the equipment necessary, and do not constitute a
manufacturer or vendor endorsement.
(A) Heating mantle and control (VWR Cat. No. 33752-464)
(B) 1000 ml distilling flask with three 24/40 joints (VWR Cat. No.
29280-215)
(C) Friedricks condenser with two 24/40 joints (VWR Cat. No.
23161-009)
D-12
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(D) 125 ml separatory funnel with 24/40 joint (VWR Cat- No.
30357-102)
(E) Inlet tube with 24/40 joint (VWR Cat. No. 33057-105)
(F) Adapter joint 24/40 to 19/38 (VWR Cat. No. 62905-26)
(G) Adsorber head (2 required) (Thomas Cat. No. 9849-R29)
(H) Absorber body (2 required) (Thomas Cat. No. 9849-R32)
(I) Laboratory vacuum pump or water aspirator
Reagents.
(A) Potassium hydroxide, 6N: Dissolve 340 g of analytical
reagent grade KOH in 1 liter distilled water.
(B) Sodium hydroxide, 6N: Dissolve 240 g of analytical reagent
grade NaOH in 1 liter distilled water.
(C) Sodium hydroxide, 0.03N: Dilute 5.0 ml of 6N NaOH to 1
liter with distilled water.
(D) Hydrochloric acid, 6N: Dilute 500 ml of concentrated HC1 to
1 liter with distilled water.
(E) Potassium phosphate stock buffer, 0.5M: Dissolve 70 g
monobasic potassium phosphate in approximately 800 ml
distilled water. Adjust pH to 7.0 +_ 0.1 with 6N potassium
hydroxide and dilute to 1 liter with distilled water. Stock
solution is stable for several months at 4°C.
(F) Potassium phosphate buffer, 0.05M: Dilute 1 volume of 0.5M
potassium phosphate stock buffer with 9 volumes of distilled
water. Solution is stable for 1 month at 4°C.
D-13
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-8 -
(G) Alkaline 3 percent hydrogen peroxide: Dilute 1 volume of 30
percent hydrogen peroxide with 9 volumes of 0.03N NaOH.
Prepare this solution fresh each day of use.
(H) Preparation of stock sulfide standard, 1000 ppm: Dissolve 2.4
g reagent grade sodium sulfide in 1 liter of distilled water.
Store in a tightly stoppered container. Diluted working
standards must be prepared fresh daily and their
concentrations determined by EPA 376.1 immediately prior to
use.
(4) Sample Preservation and Storage.
Preserve unfiltered wastewater samples immediately after
collection by adjustment to pHv*9 with 6N NaOH and addition of 2 ml of 2N zinc acetate
per liter. This amount of zinc acetate is adequate to preserve 64 mg/1 sulfide under
ideal conditions. Sample containers must be covered tightly and stored at 4°C until
analysis. Samples must be analyzed within seven days of collection. If these procedures
cannot be achieved, it is the laboratory's responsibility to institute quality control
procedures that will provide documentation of sample integrity.
(5) Procedure. (See Figure 1 for apparatus layout)
(A) Place 50 ml of 0.05M pH 7.0 potassium phosphate buffer in
Trap No. 1.
(B) Place 50 ml of alkaline 3 percent hydrogen peroxide in Trap
No. 2.
(C) Sample introduction and N^ prepurge: Gently mix sample to
be analyzed to resuspend settled material, taking care not to
aerate the sample. Transfer 400 ml of sample, or a suitable
portion containing not more than 20 mg sulfide diluted to 400
D-14
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-9-
ml with distilled water, to the distillation flask. Adjust the
N2 flow so that the impingers are frothing vigorously but not
overflowing. Vacuum may be applied at the outlet of Trap
No. 2 to assist in smooth purging. The N2 inlet tube of the
distillation flask must be submerged deeply in the sample to
ensure efficient agitation. Purge the sample for 30 minutes
without applying heat. Test the apparatus for leaks during
the prepurge cycle (Snoop or soap water solution).
(D) Volatilization of H2S: Interrupt the N2 flow (and vacuum)
and Introduce 100 ml of 6N HC1 to the sample using the
separatory funnel. Immediately resume the gas flow (and
vacuum). Apply maximum heat with the heating mantle until
the sample begins to boil, then reduce heat and maintain
gentle boiling and N2 flow for 30 minutes. Terminate the
distillation cycle by turning off the heating mantle and
maintaining N2 flow through the system for 5 to 10 minutes.
Then turn off the N2 flow (and release vacuum) and
cautiously vent the system by placing 50 to 100 ml of distilled
water in the separatory funnel and opening the stopcock
carefully. When the bubbling stops and system is equalized to
atmospheric pressure, remove the separatory funneL
Extreme care must be exercised in terminating the
distillation cycle to avoid flash-over, draw-back, or violent
steam release. :
(E) , Analysis: Analyze the contents of Trap No. 2 for sulfate
according to EPA Method 375.3 (Gravimetric) or EPA Method
-------
- 10 -
375.4 (Turbidimetric) and use result to calculate mg/1 of
sulfide in wastewater sample.
(6) Calculations and Reporting of Results.
(A) Gravimetric procedure:
(mg BaSO^ collected in Trap No. 2) x (137) - mg Sulfide/1
Volume in ml of waste sample distilled
(B) Turbidimetric procedure:
(mg/1 Sulfate in Trap No. 2) x (liquid volume in 1 in Trap No. 2) x (333)
Volume in ml of waste sample distilled = mg Sulfide/1
(C) Report results to two significant figures.
(7) Quality Control.
(A) Each laboratory that uses this method is required to operate a
formal quality control program. The minimum requirements
of this program consist of an initial demonstration of
laboratory capability and the analysis of replicate and spiked
samples as a continuing check on performance. The
laboratory is required to maintain performance records to
define the quality of data that is generated. Ongoing
performance checks must be compared with established
performance criteria to determine if the results of analyses
are within precision accuracy and limits expected of the
method.
(B) Before performing any analyses, the analyst must
demonstrate the ability to gienerate acceptable accuracy and
precision by performing the following operations.
(i) Perform four rieplicate analyses of a 20 mg/1 sulfide
standard prepared in distilled water (see (3)(H)).
D-16
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-11 -
(ii) Calculate clean water precision and accuracy in
accordance with standard statistical procedures.
Clean water acceptance limits are presented below.
These criteria must be met or exceeded before sample
analyses can be initiated. A clean water standard
must be analyzed with each sample set and the
established criteria met for the analysis to be
considered under control.
Clean water precision and accuracy acceptance limits:
For distilled water samples containing from 5 to 50
mg/1 sulfide, the mean concentration from four
replicate analyses must be within the range of 72 to
114 percent of the true value.
(C) The Minimum Reportable Concentration (MRC) should be
determined periodically by each participating laboratory in
accordance with the procedures specified in Methods for
Organic Chemical Analysis of Municipal and Industrial
Wastewater - EPA-600/4-82-057 July 1982, EMSL, Cincinnati,
OH 45268.
(D) A minimum of one spiked and one duplicate sample must be
run with each analytical event, or five percent spikes and five
percent duplicates when the number of samples per event
exceeds twenty. Spike levels are to be at the MRC (See
Section (7)(C)) for MRC samples, and at x when x is the
concentration found if in excess of the MRC. Spike recovery
-------
- 12 -
must be 60 to 120 percent for the analysis of a particular
matrix type to be considered valid.
(E) Report all results In mg/liter. When duplicate and spike
samples are analyzed, report all data with the sample results.
D-18
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-13-
F1GURE 1
EQUIPMENT ASSEMBLY
ADAPTER JOINT
WATER IN
125 mi
FUNNEL
INLET
TUBE
TRAP NO.
TRAP NO. 2
_ 1000 ml
distilling flask
ADSORBER HEAD
AND BODY (2)
HEATING MANTLE
D-19
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- 14 -
IL APPLICABILITY OF THE SULFIDE PRETREATMENT STANDARDS.
Amend 40 C.F.R. § 425.04 by adding a new section 425.04(d)(1):
If, after EPA and the POTW have determined in accordance with this section
that the sulfide pretreatment standards of this Part are not applicable to specified
facilities, a POTW then determines that there have been changed circumstances
(including but not limited to changes in the factors specified in paragraph (b) of this
section) which justify application of the sulfide pretreatment standards, the POTW shall
revoke the certification submitted under paragraph (c) of this section. The POTW and
EPA shall then adhere to the general procedures and time intervals contained in
paragraph (c) in order to determine whether the sulfide pretreatment standards contained
in this Part are applicable.
Amend 40 C.F.R. § 425.04 by adding a new section 425.04(d)(2)):
If pursuant to paragraph (d)(1) of this section, the sulfide pretreatment
standards of this Part 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.
Amend 40 C.F.R. S 425.04 by adding a new section 425.04(e):
At any time after October 13, 1983, if a POTW determines that there have
been changed circumstances (including but not limited to changes in the factors specified
in paragraph (b) of this section) it may initiate the proceedings contained in paragraph (c)
of this section to determine that the sulfide pretreatment standards of this Part shall not
be applicable. The POTW and EPA shall follow the procedures and time intervals
contained in paragraph (c) of this section to make this determination. A final
determination that the sulfide pretreatment standards are not applicable must be made
prior to the discharge of sulfide not in accordance with the standards set forth in this
Part.
D-20
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- 15 -
EL SUBCATEGORY WATER USE RATIOS.
Amend 40 C.F.R. § 425.11 by substituting:
BPT Limi tat i ons
Maximum for
Any One Day
Maximum for
Monthly Average
Pol lutant or
Pollutant Property
Kg/KKg (or Pounds per
1,000 lb.) of Raw Ma t e r i a I
BODc
TSS
Oil £c Grease
Total Chromium
pH
9.3
13.4
3.9
0. 24
(1)
4.2
6. 1
1.7
0. 09
(1)
(1) Within the range 6.0 to 9.0
Amend 40 C.F.R. S 425.15(b) by substituting:
Any existing source subject to this subpart which processes less than 275
hides/day shall comply with section 425.15(a), except that the Total Chromium
limitations contained in section 425.15(a) do not apply.
Amend 40 C.F.R. § 425.31 by substituting:
BPT Limitations
Maximum for
Any One Day
Maximum for
Monthly Average
Pollutant or
Pollutant Property
Kg/KKg (or Pounds per
1,000 lb.) of Raw Ma t e r i a 1
BODc
TSS
Oi 1 <5c Grease
To t a1 Ch r om i um
PH
6.7
9.7
2.8
0. 17
(1)
3.0
4.4
1.3
0.06
(1)
(1) Within the range 6.0 to 9.0
Amend 40 C.F.R. § 425.35(a) by substituting:
D-21
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- 16 -
PSES Limitations
Maximum for
Any One Day
Maximum for
Monthly Average
Pollutant or
Pollutant Property
Milligrams Per Liter (mg/1)
Sulfide
Total Chromium
PH
24
12
(1)
(1)
8
(1) Not less than 7.0
Amend 40 C.F.R. § 425.35(b) by substituting:
Any existing source subject to this subpart which processes less than 350
hides/day shall comply with section 425.35(a), except that the Total Chromium
limitations contained in section 425.35(a) do not apply.
Amend 40 C.F.R. § 425.41 by substituting:
BPT Limitations
Maximum for
Maximum for
Pollutant or
Pollutant Property
Any One Day Monthly Average
Kg/KKg (or Pounds per
1,000 lb.) of Raw Material
bod5
TSS
Oi 1 5c Grease
Total Chromium
pH
8.9
12.8
3.7
0. 23
(1)
4.0
5.8
1.7
0.08
(1)
(1) Within the range 6.0 to 9.0
Amend 40 C.F.R. § 425.44 by substituting:
D-22
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- 17 -
NSPS Limitations
Maximum for
Any One Day
Ma x i mum for
Monthly Average
Pollutant or
Pollutant Property
Kg/KKg (or Pounds per
1,000 lb.) of Raw Ma t e r i a 1
BOD c
TSS
Oi1 & Grease
Total Chromium
PH
6.5
9.3
2.7
0. 17
(1)
2.9
4.3
1.2
0.06
(1)
(1) Within the range 6.0 to 9.0
Amend 40 C.F.R. § 425.51 by substituting:
BPT Limitations
Maximum for
Any One Day
Maximum for
Monthly Average
Pollutant or
Pollutant Property
Kg/KKg (or Pounds per
1,000 lb.) of Raw Material
BOD5
TSS
Oil ic Grease
Total Ch r om i urn
PH
8.0
11.6
3.4
0.21
(1)
3.6
5.3
1.5
0.08
(1)
(1) Within the range 6.0 to 9.0
Amend 40 C.F.R. S 425.61 by substituting:
BPT Limi tat i ons
Ma x i mum for
Any One Day
Ma x i mum for
Monthly Average
Po11utant or
Pollutant Property
Kg/KKg (or Pounds per
1 , 000 lb.) of Raw Mater i a 1
BODc
TSS
Oi 1 4c Grease
Total Chromium
pH
3.2
4.7
1.4
0. 08
(1)
1. 5
2. 1
0.61
0. 03
(1)
(1) Within the range 6.0 to 9.0
r\ o o
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- 18 -
Amend 40 C.F.R. S 425.64 by substituting:
NSPS Limi tat i ons
Maximum for Maximum for
Any One Day Monthly Average
Pollutant or
Pollutant Property
Kg/KKg (or Pounds per
1,000 lb.) of Raw Material
BODe 3.0 1.3
TSS 4.3 1.9
Oil 5c Grease 1.2 0.55
To t a1 Ch r om i um 0. 08 0. 03
pH (1) (1)
(1) Within the range 6.0 to 9.0
Amend 40 C.F.R. S 425.71 by substituting:
BPT Limitations
Pollutant or
Pollutant Property
Maximum for
Any One Day
Maximum for
Monthly Average
Kg/KKg (or Pounds per
1,000 lb.) of Raw Material
bod5
TSS
Oil & Grease
Total Chromium
PH
15.0
21.7
6.3
0.39
(1)
6.8
9.9
2.8
0. 14
(1)
(1) Within the range 6.0 to 9.0
Amend 40 C.F.R. § 425.91 by substituting:
BPT Limi tat ions
Maximum for Maximum for
Any One Day Monthly Average
Pollutant or Kg/KKg (or Pounds per
Pollutant Property 1,000 lb.) of Raw Ma t e r i a 1
bod5
5.8
2.6
TSS
8.3
3.8
Oi1 & Grease
2.4
1.1
To t a1 Ch r om i um
0.15
0. 05
pH
(1)
(1)
(1) Within the range 6.0 to 9.0
D-24
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- 19 -
Amend 40 C.F.R. § 425.95(b) by substituting:
Any existing source subject to this subpart which processes less than 3,600
splits/day shall comply with section 425.95(a), except that the Total Chromium
limitations contained in section 425.95(a) do not apply.
D-25
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EXHIBIT B
PREAMBLE LANGUAGE TO 40 C.F.R. PART 425
L SUBCATEGORY WATER USE RATIOS.
Add the following preamble language;
After reviewing the revised data base for the subcategory median and new
source water use ratios, EPA determined that changes should be made in the median
water use ratios for a number of subcategories. Table 1 reflects the revisions in median
water use ratios as well as changes in the number of plants in the subcategory data bases
and the number of plants achieving the median water use ratios. Table 2 reflects the
revisions in the new source water use ratios and in the number of plants achieving these
water use ratios.
TABLE 1
Number of plants
Number of plants in data base
in subcategory Median water use ratio achieving water
Subcategory data base (gallons per pound) use ratio
1
34
6.6
17
2
4
5.8
3
3
11
4.8
6
4
7
6.3
4
5
10
5.7
5
6
3
2.3
2
7
2
10.7
1
8
2
5.0
1
9
6
4.1
3
D-26
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-2-
TABLE 2
New source water use ratio Number of plants in data
Subcategory (gallons per pound) base achieving water use ratio
1 4.3 6
2 4.9 1
3 4.2 4
4 4.6 2
5 3.8 3
6 2.1 1
1 9.4 1
8 4.1 1
9 2.5 2
IL SMALL TANNERY EXEMPTION.
Add the following preamble language:
In a correction notice dated June 30, 1983, the Agency specified the annual
weight basis as well as the number of working days per year underlying the specified hide
and split limits. 48 Fed. Reg. 30,115. Subsequent to discussing this matter with TCA,
the Agency has reconsidered this issue. The Agency plans to delete all references to the
annual weight basis and the number of working days per year underlying the specified
hide and split limits. Accordingly, tanneries with a seven-day work week could qualify
for the exemption.
Add the following preamble language;
The pretreatment standards for chromium are not applicable to plants with
mixed subcategory operations if the greatest part of the plant's production is in either
subcategory 1, 3 or 9 and if the total plant production Is less than the specified number
of hides or splits per day for the particular subcategory. The intent of this exemption is
to exclude small plants from the chromium pretreatment standards, not to exclude
processing operations at medium or large plants.
TX_ /I
-------
EL CHANGES IN SPBCATEGORIZATION.
Add the following preamble language:
Under 40 C.F.R. S 403.6(a) of the general pretreatment regulations, an
existing industrial user or a POTW may seek written certification from the Agency as to
whether the industrial user falls within a particular subcategory of a promulgated
categorical pretreatment standard. Existing users must make the request within 60 days
after the effective date of a pretreatment standard for a subcategory under which the
user may be included or within 60 days after the Federal Register notice announcing the
availability of the technical document for the subcategory. New sources must request
this certification prior to commencing discharge.
Persons have inquired as to the procedures that existing leather tanning
facilities should use to seek an Agency determination if the facility decides to change its
subcategorization subsequent to the expiration of the 60-day deadline under 40 C.F.R. S
403.6(a). In fact, 40 C.F.R. § 403.6(a) does not preclude leather tanning and finishing
facilities from changing operations which would in turn automatically change their
subcategorization status. Facilities that are planning to change their subcategorization
status and are unsure which subcategory they will fall into, should request written
certification from the Agency as to whether the facility falls within a particular
subcategory prior to commencing discharges which would fall within that subcategory.
IV. MULTIPLE OUTFALLS.
Add the following preamble language:
Most indirect discharging plants combine their process wastewaters and
discharge them all through one outfalL The Agency has costed this approach by including
D-28
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- 4 -
costs for internal plant piping for wastewater collection as well as contingency costs to
account for any unforeseen site specific costs.
If, however, an indirect discharging plant does not choose to combine its
process wastewaters for treatment and to discharge them through one outfall, a
composite sampling of the multiple outfalls could be acceptable. A single composite
sample for multiple outfalls must be comprised of representative process wastewaters
from each outfall. A composite sample must be combined in proportions determined by
the ratio of the process wastewater flow in each outfall to the total flow of process
wastewaters discharged through all outfalls. U Flow measurements for each outfall
must be representative of the plant's operation. An analysis of the total sample would
then be compared to the applicable categorical standard to determine compliance.
If non-process wastewater is combined with process wastewater or if a plant has
operations in more than one subcategory, the plant would have to use the "combined
wastestream formula" (40 C.F.R. S 403.6(e)) to make this calculation.
r*v or*
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EXHIBIT C
TCA MEMBERS
kcme Sponge & Chamois Co.
Allied Leather Co. (Feuer)
Imdur Braude Riley, Inc.
American Leather Mfg. Co.
Irmira Company
Jadger State Tanning Corp.
Beatrice, Leather Div.
I eggs dc Cobb Corp.
Berkshire Tanning Corp.
Uackhawk Tanning Co., Ltd.
'he Blueside Companies, Inc.
Caldwell Lace Leather Co.
'alnap Tanning Company
Jamden Tanning Corp.
Jarr Leather Company
Jayadutta Tanning Company
Classic Leather Corporation
Joey Tanning Company, Inc.
Jollins-Johnsen, Inc.
Jonneaut Leather, Inc.
Cromwell Leather Co., Inc.
)el-Tan Corporation
)elta Tanning Corporation
)reher Leather Mfg. Corp.
lagle Ottawa Leather Company
:iIithorp Tanning Company
'ashion Tanning Company, Inc.
'ermon Leather Company
euer Leather Group
'aul Flagg, Inc.
ohn Flynn &. Sons, Inc.
.B. Foot Tanning Co.
'he Fouke Company
ox Valley Leathers, Inc.
roritier Leather Co., Inc.
l.F. Gallun <5c Sons Corp.
iarden State Tanning
5prJ>n <5c Company, Inc.
k.L. Gebhardt Company
>eneral Split Corporation
>«nesco, Inc.
iordon-Gruenstein, Inc.
Sranite State Leathers, Inc.
iunnison Brothers, Inc.
lermann Oak Leather Company
lorizon Leather Company
Horween Leather Company
Howes Leather Company, Inc.
Hoyt & Worthen Tanning Corp.
Huch Leather Company
Irving Tanning Company
JBF Industries, Inc.
JEC Tanning Company, Inc.
Kroy Tanning Company, Inc.
Lackawanna Leather Company
Lannom Tannery
A.C. Lawrence Leather Co., Inc.
Leathers Best, Inc.
Liberty Leather Corp.
Hermann Loewenstein, Inc.
Los Angeles Tanning Company
MTE Corporation
Manasse-Block Tanning Company
Mason Tanning Company, Inc.
Master Inc.
Middlesboro Tanning Co. of DeL
Middlesboro Tanning Company
Midwest Tanning Company
Moench Tanning Company
Moran Leather Company
George Moser Leather Co., Inc.
New Jersey Tanning Co., Inc.
Norwich Leather Company
Ocean Leather Corp.
Pfister & Vogel Tanning Co.
W.B. Place & Company
Poetsch & Peterson
Pollet Leather Co.
Prime Tanning Company, Inc.
Radel Leather Manufacturing Co.
Re mis Industries
W.C. Reynolds Company, Inc.
Richard Leather Co., Inc.
John J. Riley Company
A.H. Ross & Sons Co.
Fred Rueping Leather Co.
F. Rulison and Sons, Inc.
Salz Leather, Inc.
Sawyer Tanning Company
Scholze Tannery
Schwarz Leather Corp.
Seidel Tanning Corp.
Seton Leather Corp.
Shrut & Asch Leather Co., Inc.
Stock Kojima
The Sidney Tanning Company
Sierra Pine Tanning Company
Sigma Leather, Inc.
Sirois Leather,Inc.
Slip-Not Belting Corporation
John Smidt Co. Inc.
Steinberg Bros., Inc.
Suncook Tanning Corporation
Tanners' Council Laboratory
Tennessee Tanning Company
Texas Tanning
Thiele Tanning Company
Travel Leather Company, Inc.
Twin City Leather Company, Ir
Vernon Leather Company
Victory Tanning Corporation
Volunteer Leather Company
Western Leather Products Corp
Whitehall Leather Company
Wolverine Leather Division
Wood and Hyde Leather Compa
D-30
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