SW-131c
U.S. DEPARTMENT OF COMMERCE
National Technical Information Service
PB-261 018
ASSESSMENT OF INDUSTRIAL HAZARDOUS WASTE PRACTICES
LEATHER TANNING AND FINISHING INDUSTRY
SCS ENGINEERS., INC,
NOVEMBER 1976
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BIBLIOGRAPHIC DATA 1. Report No. 2.
SHEET
4. Title and Subtitle
Assessment of Industrial Hazardous Waste Practices —
Leather Tanning and Finishing Industry
7. Au,hor E. T. conrad, Gary L. Mitchell, David H. Baue
9. Performing Organization Name and Address
SCS Engineers, Inc.
11800 Sunrise Valley Drive
Reston, Virginia 22091
12. Sponsoring Organization Name and Address
EPA, Hazardous Waste Management Division •
Office of Solid Waste Management Programs
401 M. Street, S.W.
Washington. D'C. ?nAftn
3. Recipient1!. Acrrs-.ion No._
i PB-261 018
5. Report Date
November 1976
6.
.8. Performing Orpiiiiriinon Krpt.
No.
10. Proiect/Taslc/Vork Unit No.
11. Contract/Grant No.
EPA No. 68-01-3261
13. Type of Report & Period
Covered Final
rune 1975 to Noyembe:
14.
15. Supplementary Notes
EPA Project Officer - Allen Pearce
16. Abstracts
rh is report, which covers the leather tanning and finishing industry, is one of a series of studies which examines land-
aentined waste from selected industries. Por purposes of this study, the tanning industry has been categorised by the
types of process solid wastes generated. A total of seven different categories were established.
rocesa sol-rt wastes from the industry consist primarily of pieces of leather in various stages of processing and w.iste-
water treatnent sludqes. Virtually every tannery waste stream (except those in vegetable tanneries) was designated as
ha=.ir.1ous. Th" concentration of heavy metals (particularly trivalont chroniun, load, COMX.T, and mac}
h.Te foj-c! to t: at levels such that the wastes containing these constituents were considered to be potentially
m-..iii!^.:j. l.iter.xti-re concern'nr the hazardous nature of trivalont chromium was conflict Ing. In 1974, •inn'!'
ff.-ei.ff* ,vatoter.ti.V.iy
rics
wan
ro..tnent Cf t.-.!»ncrv ..istes «* restricted to th« dc-witcrinu of w.ijtuwater treatment sludges,. Sludgea .md otl.or tannery
•-•tc.- pri-£1oT.n.inll> arc boir.j disposed directly to the Innd. Approxliiutely 60 rrrocnt of the r-'->t.cnfi..lly hiixardaun
«.n-ri «-a:--.es is disposoil in some form of landfill with the remainder (Ucposed Jn trenches or l.igooni.
stinatea are given for the cost of potentially hazardous waste treatment and disposal for each category of tannery
nd for each of the three levels of treatment and disposal.
17. Key Vords and Document Analysis. 17o. Descriptors
Leather
Tanning
Hazardous Wastes
Process Wastes
Treatment Technology
Disposal Technology
Landfill
7b. Identifiers/Open-Ended Terms
PUCES SUBJECT TO CHAKGE
17c. COSATI Field/Group
REPRODUCED Bf
NATIONAL TECHNICAL
INFORMATION SERVICE
U. S. DEPARTMENT OF COMMERCE
SPRINGFIELD. VA, 22161
18. Availability Statement
NTIS-SB (RRV. 1O-73I
ENDORSED BY ANSI AND UNESCO.
19. Security Class (This
Report)
[21. No. of Pages
20. Security Class (This
Page
UNCLASSIFIED
THIS FORM MAY BE REPRODUCED
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16. Abstracts
This report, which covers the leather tanning and finishing Industry, 1s one of a series
of studies which examines land-destined waste from selected Industries. For purposes of
this study, the tanning Industry has been categorized by the types of process solid
wastes generated. A total of seven different categories were established.
Process solid wastes from the Industry consist primarily of places of leather 1n various
stages of processing and wastewater treatment sludges. Virtually every tannery waste
stream (except thos In vegetable tanneries) was designated as potentially hazardous. The
concentration of heavy metals (particularly trlvalerit chromium, lead, copper, and zinc)
were found to be at levels such that the wastes containing these constituents were
considered to be potentially hazardous. Literature concerning the hazardous nature of
trlvalent chromium was conflicting. In 1974, tanneries generated approximately 200,000
metric tons of total process solid wastes of which approximately 75 percent was considered
potentially hazardous.
Treatment of tannery wastes Is restricted to the dewaterlng of wastewater treatment sludges,
Sludges and other tannery wastes predominantly are being disposed directly to the land.
Approximately 60 percent of the potentially hazardous tannery wastes Is disposed In some
form of landfill with the remainder disposed 1n trenches or lagoons.
Estimates are given for the cost of potentially hazardous waste treatment and disposal for
each category of tannery and for each of the three levels of treatment and disposal.
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034
LEATHER TANNING AND FINISHING INDUSTRY
Assessment of Industrial Hazardous Waste Practices
_
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This final report (SW-131c) describes work performed for the
Federal solid waste management program
under contract no. 68-01-3261
and is reproduced as received from the contractor
U.S. ENVIRONMENTAL PROTECTION AGENCY
1976
Chicago. »L
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This report has been reviewed by the U.S. Environmental
Protection Agency and approved for publication. Approval
does not signify that the contents necessarily reflect the
views and policies of the U.S. Environmental Protection
Agency, nor does mention of commercial .products constitute
endorsement by the U.S. Government.
ii
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TABLE OF CONTENTS
1.0 EXECUTIVE SUMMARY 1
1.1 Introduction 1
1.1.1 Coverage 1
1.1.2 Approach 2
1.1.3 Methodology 2
1.2 Industry Characterization 3
1.2.1 Magnitude of the Industry 3
1.2.2 Geographical Distribution 3
1.2.3 Categorization Criteria 5
1.3 Waste Characterization 6
1.3.1 Process Solid Wastes 6
1.3.2 Potentially Hazardous Wastes 12
t\e 1.4 Treatment and Disposal Technology 15
' 1.4.1 Treatment 15
eg 1.4.2 Disposal 16
X. 1.4.3 Alternatives to Disposal 18
1.5 Cost Analysis 20
1.5.1 Treatment 20
1.5.2 Disposal 20
1.5.3 Summary and Discussion 21
2.0 INDUSTRY CHARACTERIZATION 29
2.1 The Tanning Industry 29
2.1.1 Introduction to Tanning 29
2.1.2 Background 3 3
2.1.3 Industry Organization and 36
Structure
2.1.4 Industry Trends and Future 37
Developments
2.2 Approaches to Characterizing Tanneries 40
2.2.1 Census of Manufactures 40
2.2.2 Production 4 0
2.2.3 Tanning Process 41
2.2.4 Raw Material 41
2.2.5 Industry Categorization 45
iii
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3.0 WASTE CHARACTERIZATION 49
3.1 Development of Typical Plants 49
3.1.1 Approach to Waste Characterization 49
3.2 Determination of Potentially 52
Hazardous Waste
3.2.1 Criteria 52
3.2.2 Definition of Potentially 54
Hazardous Waste
3.2.3 Discussions of Hazardous 56
Constituents
3.3 Complete Chrome Tannery 61
3.3.1 Plant Operations 61
3.3.2 Potentially Hazardous Solid 64
Waste
3.3.3 Non-Hazardous Solid Waste 68
3.3.4 Factors Affecting Future Solid 68
Waste Generation
3.3.5 Typical Plant Summary 69
3.3.6 EPA Region and National Waste 69
Summary
3.4 Vegetable Tannery 80
3.4.1 Plant Operations 80
3.4.2 Process Solid Waste 80
3.4.3 Factors Affecting Future Solid 83
Waste Generation
3.4.4 Typical Plant Waste Summary 83
3.4.5 EPA Region and National Waste '84
Summary
3.5 Sheepskin Tannery 84
3.5.1 Plant Operations '84
3.5.2 Potentially Hazardous Solid 86
Waste
3.5.3 Non-Hazardous Solid Waste 88
3.5.4 Factors Affecting Future Solid 88
Waste Generation
3.5.5 Typical Plant Waste Summary 89
3.5.6 EPA Region and National Waste 89
Summary
iv
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3.6 Split Tannery 94
3.6.1 Plant Operations 94
3.6.2 Potentially Hazardous Solid 94
Waste
3.6.3 Non-Hazardous Solid Waste 97
3.6.4 Factors Affecting Future Solid 97
Waste Generation
3.6.5 Typical Plant Waste Summary 98
3.6.6 EPA Region and National Waste 98
Summary
3.7 Leather Finishers 98
3.7.1 Plant Operations 98
3.7.2 Potentially Hazardous Solid 98
Waste
3.7.3 Non-Hazardous Solid Waste 104
3.7.4 Factors Affecting Future Solid 104
Waste Generation
3.7.5 Typical Plant Waste Summary 105
3.7.6 EPA Region and National Waste 105
Summary
3.8 Beamhouse/Tanhouse Facilities 110
3.8.1 Plant Operations HO
3.8.2 Potentially Hazardous Solid HO
Waste
3.8.3 Non-Hazardous Solid Waste 112
3.8.4 Factors Affecting Future Solid H2
Waste Generation
3.8.5 Typical Plant Waste Summary H3
3.8.6 EPA Region and National Waste 113
Summary
3.9 Retan/Finishers 117
3.9.1 Plant Operations 117
3.9.2 Potentially Hazardous Solid H7
Waste
3.9.3 Non-Hazardous Solid Waste 120
3.9.4 Factors Affecting Future Solid 120
Waste Generation
3.9.5 Typical Plant Waste Summary 121
3.9.6 EPA Region and National Waste 121
Summary
3.10 State and EPA Regional and National 129
Waste Quantities
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4.0 TREATMENT AND DISPOSAL TECHNOLOGY 135
4.1 Introduction 135
4.1.1 In-Plant Management 135
4.1.2 Collection and Hauling 135
4.1.3 Treatment and Disposal 136
4.2 Present Treatment and Technologies 137
4.2.1 Non-Mechanical Devatering 137
4.2.2 Mechanical Devatering 137
4.3 Present Disposal Technologies 138
4.3.1 Open Dumping 138
4.3.2 Landfilling 139
4.3.3 Certified Hazardous Wast* 141
Disposal Facilities
4.3.4 Disposal in Lagoons, Trenches* 142
Pits, and Ponds
4.3.5 Agricultural Spreading 142
4.4 Alternatives to Disposal 143
4.4.1 Municipal Sewage Treatment 143
4.4.2 Source Reduction Through In-Plant 144
Process Change
4.4.3 Sale as By-Products 145
4.5 Approach to the Selection of Treatment 147
and Disposal Technologies
4.5.1 Technology Levels 147
4.5.2 Treatment 147
4.5.3 Disposal 148
4.5.4 Outline of Subsequent Sections 148
4.6 Treatment and Disposals Complete 149
Chrome Tanneries
4.6.1 Treatment 149
4.6.2 Disposal 151
4.7 Treatment and Disposals Sheepskin 151
Tanneries
4.8 Treatment and Disposals Split 152
Tanneries
4.9 Treatment and Disposals Leather 154
Finishers
vi
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Page
4.10 Treatment and Disposal: Beamhouse/ 157
Tanhouse Facility
4.10.1 Treatment 157
4.10.2 Disposal 159
4.11 Treatment and Disposal: Retan/ 159
Finishers
4.12 Treatment and Disposal Technologies 161
and Waste Quantity Summary
5.0 COST ANALYSIS 165
5.1 Bases and Criteria for Cost 165
Estimation
5.1.1 Capital Costs 165
5.1.2 Interest Costs 165
5.1.3 Time Index for Costs 167
5.1.4 Useful Service Life 167
5.1.5 Depreciation 167
5.1.6 Operating Expenses 167
5.2 On-Site Waste Treatment 167
5.3 Off-Site Disposal 168
5.4 Treatment and Disposal Costs 168
5.5 Variables Effecting Treatment and 181
Disposal Costs
5.5.1 Size 181
5.5.2 Processing Operations 181
5.5.3 Location 181
5.5.4 Method of Dewatering Sludge 182
5.6 Sample Cost Calculation 182
5.6.1 Level I Technology 182
5.6.2 Level II Technology 184
5.6.3 Level III Technology 184
6.0 REFERENCES 187
7.0 ACKNOWLEDGEMENT S 191
vii
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Page
8.0 GLOSSARY 193
9.0 APPENDICES 197
A Alphabetical Listing of Establishments 199
in the Leather Tanning and Finishing
Industry
B Outline of Procedures for Field Visits, 213
Sample Collection* and Sample Analysis
C Private Disposal Sites Accepting 229
Tannery Waste
D Methodology for Projecting Waste 231
Quantities on a State, EPA Regional,
and National Basis
viii
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LIST OF TABLES
Table Page
1 Total Process and Potentially Hazardous 8
Solid Waste Generated by All Types of
Tanneries in 1974
2 Total Process and Potentially Hazardous 9
Solid Waste Generated by All Types of
Tanneries in 1977 (Projected)
3 Total Process and Potentially Hazardous 10
Solid Waste Generated by All Types of
Tanneries in 1983 (Projected)
4 Potentially Hazardous Tannery Wastes 14
5 Treatment and Disposal Technology Levels 17
and Associated Potentially Hazardous
Waste Quantities
6 Summary of Treatment and Disposal Costs 22
for the Typical Tanneries
7 Annual Treatment and Disposal Costs 26
8 1974 Tannery Production by State 35
9 Distribution of Tanneries by Size 42
10 Distribution of Tanneries by Tanning 43
Process
11 Distribution of Tanneries by Raw 44
Material
12 Distribution of Tanneries by Category 48
13 Geometric Mean Compositions, and 55
Geometric Deviations, of Samples of
Soils and Other Surficial Materials
in the Conterminuous United States
14 Potentially Hazardous Tannery Wastes 57
15 Summary of Toxicity-Related Information 58
for Chromium (III), Lead, Zinc, and
Copper
ix
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Table Page
16 Trivalent Chromium Toxicity to Aquatic 62
Organisms
17 Haste Generation Factors for a Complete 70
Chrome Tannery
18 Total Process and Potentially Hazardous 71
Waste Generated in 1974 by Complete
Chrome Tanneries
19 Total Process and Potentially Hazardous 74
Waste Anticipated to be Generated in
1977 by Complete Chrome Tanneries
20 Total Process and Potentially Hazardous 77
Waste Anticipated to be Generated in
1983 by Complete Chrome Tanneries
21- Total Process and Potentially Hazardous 85
Waste Generated by Vegetable Tanneries
22 Waste Generation Factors for a Typical 90
Sheepskin Tannery
23' Total Process and Potentially Hazardous 91
Waste Generated in 1974 by Sheepskin
Tanneries
24 Total Process and Potentially Hazardous 92
Waste Anticipated to be Generated in
1977 by Sheepskin Tanneries
25 Total Process and Potentially Hazardous 93
Waste Anticipated to be Generated in
1983 by Sheepskin Tanneries
26 Waste Generation Factors for a Typical. 99
Split Tannery
27 Total Process and Potentially Hazardous 100
Waste Generated in 1974 by Split
Tanneries
28 Total Process and Potentially 'Hazardous 101
Waste Anticipated -to be Generated in
1977 by Split Tanneries
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Table
29 Total Process and Potentially Hazardous
Waste Anticipated to be Generated in
1983 by Split Tanneries
30 Waste Generation Factors for a Typical 106
Leather Finisher
31 Total Process and Potentially Hazardous 107
Waste Generated in 1974 by Leather
Finishers
32 Total Process and Potentially Hazardous 108
Waste Anticipated to be Generated in
1977 by Leather Finishers
33 Total Process and Potentially Hazardous 109
Waste Anticipated to be Generated in
1983 by Leather Finishers
34 Total Process and Potentially Hazardous 114
Waste Generated in 1974 by Beamhouse/
Tanhouse Facilities
35 Total Process and Potentially Hazardous 115
Waste Anticipated to be Generated in
1977 by Beamhouse/Tanhouse Facilities
36 Total Process and Potentially Hazardous 116
Waste Anticipated to be Generated in
1983 by Beamhouse/Tanhouse Facilities
37 Waste Generation Factors for a Typical 122
Retan/Finisher
38 Total Process and Potentially Hazardous 123
Waste Generated in 1974 by Retan/
Finishers
39 Total Process and Potentially Hazardous 125
Waste Anticipated to be Generated in
1977 by Retan/Finishers
40 Total Process and Potentially Hazardous 127
Waste Anticipated to be Generated in
1983 by Retan/Finishers
41 Total Process and Potentially Hazardous 130
Solid Waste Generated by All Types of
Tanneries in 1974
xi
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Page
Total Process and Potentially Hazardous 131
Solid Haste Generated by All Types of
Tanneries in 1977 (Projected)
43 Total Process and Potentially Hazardous 132
Solid Waste Generated by All Types of
Tanneries in 1983 (Projected)
44 Treatment and Disposal Technology Levels 150
for Complete Chrome Tannery
45 Treatment and Disposal Technology Levels 153
for Sheepskin Tannery
46 Treatment and Disposal Technology Levels 155
for Split Tannery
47 Treatment and Disposal •technology Levels 156
for Leather Finishers
48 Treatment and Disposal Technology Levels 158
for Beamhouse/Tanhouse Facility
49 Treatment and Disposal Technology Levels 160
for Retan/Finishers
50 Treatment and Disposal Technology Levels 162
and Associated Potentially Hazardous
Waste Quantities
51 Bases and Criteria for Cost Estimation 166
52 Contractor Hauling and Disposal Costs 169
53 Treatment and Disposal Costs - Typical 171
Complete Chrome Tannery Without
Primary and/or Secondary Wastewater
Treatment
54 Treatment and Disposal Costs - Typical I7'2
Complete Chrome Tannery With Primary
and/or Secondary Wastewater Treatment
55 Treatment and Disposal -Costs - Typical 173
Sheepskin Tannery
56 Treatment and Disposal Costs - Typical 174
Split Tannery
xii
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Table Page
57 Treatment and Disposal Costs - Typical 175
Leather Finisher
58 Treatment and Disposal Costs - Typical 175
Beamhouse/Tanhouse Facility
59 Treatment and Disposal Costs - Typical 177
Retan/Finisher
60 Annual Treatment and Disposal Costs 180
xiii
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LIST OF FIGURES
Figure Pag*
1 Distribution of Tanneries 4
2 Potentially Hazardous Solid 11
Waste Generated in 1974
3 Typical Tanning Process Steps 30
4 Example of Wastestream Matrix 51
5 Process Flow Diagram - Typical 63
Complete Chrome Tannery
6 Process Flow Diagram - Typical 81
Vegetable Tannery
7- Process Flow Diagram - Typical 87
Sheepskin Tannery
8 Process Flow Diagram - Typical 95
Split Tannery
9 Process Flow Diagram - Typical 103
Leather Finisher
10 Process Flow Diagram - Typical 111
Beamhouse/Tanhouse
11 Process Flow Diagram - Typical 118
Retan/Finisher
xiv
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SECTION 1.0
EXECUTIVE SUMMARY
1.1 Introduction
This industry study is one of a series by the Office
of Solid Waste Management Programs, Hazardous Waste
Management Division. The studies were conducted for
information purposes only and not in response to a Congressional
regulatory mandate. As such, the studies serve to provide
EPA with: (1) an initial data base concerning current and
projected types and quantities of industrial wastes and
applicable disposal methods and costs; (2) a data base for
technical assistance activities; and (3) as background for
guidelines development work pursuant to Sec. 209, Solid
Haste Disposal Act, as amended.
The definition of "potentially hazardous waste" in this
study was developed based upon contractor investigations and
professional judgment. This definition does not necessarily
reflect EPA thinking since such a definition, especially in
a regulatory context, must be broadly applicable to widely
differing types of waste streams. Obviously, the presence
of a toxic substance should not be the major determinant of
hazardousness if there were mechanisms to represent or
illustrate actual effects of wastes in specific environments.
Thus, the reader is cautioned that the data presented in
this report constitute only the contractor's assessment of
the hazardous waste management problem in this industry. EPA
reserves its judgments pending a specific legislative
mandate.
1.1.1 Coverage. Process solid waste in the leather
tanning and finishing industry is the subject of this study.
The tanning industry is designated by SIC 3111. Relevant
to this study are those establishments within SIC 3111 with
production facilities.
Process solid wastes (including liquid sludges) are
generated directly as a result of production operations and
destined for land disposal. Thus, solid waste associated
with in-plant storage or movement of material, e.g., broken
pallets, general office waste, and cafeteria waste, was not
a part of the project. Similarly, wastewater and air emissions
were not included; however, solids resulting from wastewater
pretreatment or treatment and residues collected by air
pollution control devices were included if disposed to the
land.
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1.1.2 Approach. Specific tasks of the project were
as follows:
Characterize the industry in terms of number, size,
and location of plants.
Determine the types, quantities, and sources of
total process solid wastes and potentially hazardous
wastes currently generated by tanneries and project
quantities for 1977 and 1983.
Sample and analyze the solid waste to determine the
presence and concentration of potentially hazardous
constituents.
. Define potentially hazardous solid wastes applicable
to the tanning industry, and characterize the process
waste streams as non-hazardous or potentially
hazardous using the definition.
Identify current and potential future methods of
treatment and disposal for the potentially hazardous
solid wastes and describe three technology levels:
Level I—most commonly used current technology.
Level II—best current technology in full-scale
operation
Level III—technology necessary to provide
adequate health and environmental protection.
Estimate the costs of potentially hazardous waste
treatment and disposal"for the industry.
1.1.3 Methodology. The collection of information
necessary to meet the above objectives required field visits
to various tanneries and the collection and analysis of solid
waste samples. Field visits to disposal sites serving tanneries
were also an integral part of the project. Tanneries were
selected on the basis that they represented the major types
of tanning operations carried on in this country and thus
generated solid wastes typical of the industry.
Field visits to tanneries were conducted by staff
personnel, sometimes augmented by industry or EPA officials.
During the visits, waste management information was collected
utilizing standardized data collection forms. Production
operations were examined, and solid waste samples were
collected at selected tanneries. The samples were shipped
to a laboratory for analysis. Land disposal sites were
visited whenever possible. A total of 23 sites which receive
tannery solid wastes were visited. Often tanneries were
selected for visits because they were known to have advanced
treatment technology or unique disposal methods. A total
of 41 tanneries were visited during the project. They
represented 14 percent of the plants in the industry and nearly
50 percent of the industry's production nationwide.
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1.2 Industry Characterization
1.2.1 Magnitude of the Industry. The total number of
establishments in the leather tanning and finishing industry
is 298. According to the U.S. Bureau of the Census, there are
517 establishments in the leather tanning and finishing
industry, SIC 3111.x However, many of the establishments
included in the Census report have no actual leather
processing facilities, and therefore were not included as a
part of the study. For purposes of this study, the following
types of facilities have been eliminated from the Census
figures:
Converters.
Double entries.
Hobbyists and taxidermists.
Other nonproduction establishments.
Most of the tanneries in this country are relatively
small, family owned businesses. Employment ranges from 5
to 500, and production ranges from less than 200 hides per
day to over 2,600 hides per day.2 The Bureau of the Census
reports the value of industry shipments in 1967 as $846 million
and in 1972 as $1,026 million.1 The Tanners' Council of
America estimates 1974 value of shipments at $1,026 million.
The sum of the production for all types of tanneries
in 1974 is estimated at 35.7 million equivalent hides.2 This
is the total of all hides put into production by all categories
of tanneries. Total output production for 1974 was
approximately 20 million equivalent hides.2 The difference
is due to the fact that hides may be counted twice. A single
hide put into production at a tannery is usually split
(sliced through its thickness) after partial processing.
This yields two pieces of leather, a grain side and a split.
The grain side may be sent to a leather finisher where it is
also counted as input. The split is sent to a split tannery
where it is counted as input. Input production is used
throughout this report.
1.2.2 Geographical Distribution. Tanning is one of
the oldest industries in this country, beginning in the New
England and Middle Atlantic States (EPA Regions I, II, and III)
during colonial times. The greatest concentration of tanneries
is still found in these areas. During the 19th and 20th
centuries, tanneries have tended to follow the source of their
raw materials—cattlehides. This gave rise to the location
of tanneries west of the Mississippi River. Currently,
there are tanneries in 34 states. Figure 1 illustrates the
geographical distribution of tanneries in the nation. As
shown, approximately 30 percent of all tanneries are located
in New York (EPA Region II) and Massachusetts (EPA Region I),
and 85 percent of all tanneries are located east of the
Mississippi River.
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FIGURE 1
DISTRIBUTION OF TANNERIES
States Containing No Tanneries
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1.2.3 Categorization Criteria. A combination of
criteria was used to categorize the tanning industry with
respect to its total process solid waste and potentially
hazardous solid waste generation. Major differences are
apparent between the two predominant types of tanning
processes—chrome tanning and vegetable tanning. Within
the chrome tanning category, processing differences based
upon the raw material (type of hide or skin) used and the
type of finished leather produced yielded additional
categories. A major operation conducted on a contract
basis is the finishing of leather. No actual tanning is
conducted by these establishments, and thus finishing is
another tannery category.
Trends in the industry were also taken into account in
the establishment of industry categories. Recently,
operational changes in the most common type of tannery
(complete chrome) have given rise to the development of
two new types of operations: the beamhouse/tanhouse facility
and the retan/finisher. Essentially, these are the operations
carried on in a complete chrome tannery with the processing
of the hides through the tanning operation conducted in the
beamhouse/tanhouse facility and the processes from retan
through leather finishing conducted by the retan/finishers.
Although these operations have been in existence for less
than 20 years, they already account for about 10 percent of
the total production in this country. It is expected that
this trend will continue.
In summary, the following industry categories were
developed for purposes of this study.
Category
Complete chrome tannery
Vegetable tannery
Sheepskin tannery
Split tannery
Rationale
The most common type of tanning
operation in the United States;
includes the chrome tanning of
cattlehides and pigskins.
The absence of chromium and other
heavy metals in tanning and
processing hides is unique to this
segment of the industry.
The importation of partially
processed sheepskins and unique
sequence of processing yields
waste streams notably different
from the complete chrome tannery.
Specialized operations on
previously tanned hides produce
waste streams with higher
generation rates than found in
complete chrome tanneries and the
lack of finishing operations
eliminates one or more waste
streams.
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Category Rationale
Leather finisher Usually a contract operation
specializing in the finishing of
leather with no tanning facilities.
Finishers normally have only
one or two of the waste streams
found in the complete chrome
tannery.
Beamhouse/tanhouse The two "halves" of the complete
facility and chrome tannery. A trend towards
Retan/finisher separating tanning operations
geographically with partial
processing near the source of the
raw material and completion in
another location gives rise to
these two categories.
1.3 Waste Characterization
1.3.1 Process Solid Wastes. Pieces of leather (containing
10 to 50 percent moisture) in various stages of processing,
and wastewater treatment sludges constitute the bulk of the
process solid wastes from tanneries. In order to produce the
quality products required by leather consuming industries,
tanneries trim off inferior portions of hides at many
steps in processing. Smaller pieces of leather wastes are
produced in shaving and buffing operations. Approximately
35 percent of all tannery solid waste is trimmings and
shavings of various types.
Another source of tannery wastes is the finishing
department. Finishes are sprayed or rolled onto leather
and the residue is considered to be a solid waste since it is
land disposed. Finish residues are usually slurries containing
10 to 50 percent solids. Waste finishes account for about 2
percent of tannery solid waste.
Wastewater treatment is the single largest source of
process solid waste. Almost all tanneries screen their
wastewater. Direct dischargers and some discharging wastewater
into municipal sewers have some form of primary or secondary
treatment (only direct dischargers use secondary treatment).
The screenings and sludges from these operations contain lime,
chromium compounds, pieces of leather, hair, and other
protein-like substances which are land disposed. Wastewater
screenings and sludge account for about 60 percent of tannery
solid waste.
Floor sweepings are the final source of process solid
waste. These include twine used to tie bundles of hides,
salt used to preserve the hides prior to tanning, and general
plant debris. Approximately 3 percent of tannery solid waste
is floor sweepings.
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Tables 1 through 3 provide estimates of the state,
EPA Region, and national quantities of tannery process solid
waste destined for land disposal. The data presented is
based on the quantity of solid waste generated at the 41
tanneries visited (in units of kg per equivalent hides).
Data for states with less than three tanneries has been
combined in order to protect the confidentiality of production
information.
As shown in Table 1, more tannery process solid wastes
and potentially hazardous solid wastes are generated in
Massachusetts than in any other state, followed by Wisconsin
and New York. Similarly, approximately one-half of the
total process and potentially hazardous solid waste generation
occurs in EPA Regions I and V. Minor amounts of solid waste
are generated in EPA Regions VI, VIII, and X. In most states,
the potentially hazardous solid waste generated represents
about 90 to 95 percent of the total process solid waste.
Significant exceptions ot this pattern occur in states such
as Pennsylvania, Georgia, Kentucky, and Virginia, where most
or all of the production occurs in vegetable tanneries. As
discussed below, vegetable tanneries do not generate potentially
hazardous solid waste.
Figure 2 diagramatically shows the relative quantity of
potentially hazardous waste currently (1974) generated in
each state. As indicated, Massachusetts and Wisconsin are the
only states which generate more than 20,000 metric tons per
year, and California, New York, and Maine are the only three
states which generate between 10,000 and 20,000 metric tons
per year. Tennessee is the only southern state (EPA Regions
IV and VI) which generates more than 1,000 metric tons per
year. West Virginia, Georgia, and Indiana have only vegetable
tanneries and therefore do not generate potentially hazardous
solid waste.
Tables 2 and 3 show the distribution by state of total
process and potentially hazardous waste generation projected
for 1977 and 1983, respectively. As indicated, waste generation
is projected to increase gradually through 1983 in all states
except those with a large proportion of vegetable tanneries.
This trend is anticipated since production of chrome tanned
cattlehides and pigskins is expected to increase, while
vegetable tanned and sheepskin leather production is expected
to decline. In addition, the proportion of total process
solid waste which is potentially hazardous is projected to
increase slightly as a result of increasingly stringent
wastewater pretreatment and direct discharge standards. Most
new wastewater treatment facilities are projected to be installed
at complete chrome tanneries and beamhouse/tanhouse facilities.
Consequently, increases in the portion of total process solid
waste which is potentially hazardous will be most notable
in states with a high proportion of other types of tanneries
(vegetable tanneries, leather finishers, etc.), such as
Pennsylvania.
-------
TABLE 1
TOTAL PROCESS AND POTENTIALLY HAZARDOUS SOLID WASTE
GENERATED BY ALL TYPES OF TANNERIES IN 1974
(metric tons per year, wet and dry basis)
State (s)
AK.WA
AZ.CA
CO.OT
DE
PL,GA
IL
IN, OH
**•"*
KY
LA.TX
ME,VT
ND,VA,WV
MA
MI
MN
MO
NH
NJ
NY
NC
OR
PA
TN
WI
Total
Region I
II
III
IV
V
VI
VII
VIII
IX
X
"reduction
(thousands of
equivalent hides)
28
1.870
221
230
169 H
1.631
20C
512
4:
11
7
17
2.630
1.150
8.273
1.147
898
774
1.670
1.340
4.020
21
-1
115
: .860
: .230
- .980
35,700
«!r17fl
1-740
2-040
1
107
1 ,99
n
•>•»!
1 B70
. 143
Total
Process
Solid
Waste
Wet
192
13,200
2.09
64
<
1,950
7.500
1,390
4.69
5,48
,i
!'
845
13,160
14, ;i
31. !(
7.(i
6,' :
7,87
10,11
3,41
)
)
)
16,20)
2.42
90
i
16,00)
8.43.
25,901
203,000
55,100
19,700
31,000
18,300
49,100
846
12.570
2.090
13,200
1.100
Or/.
61
4.380
562
212
442
2.490
332
2. 25(
1.2l(
22*
< .430
; .iso
isIooO
2,49(
1.98C
2,030
3.370
1.130
5.650
238
262
4.2K
2!38(
6,500
65,000
20,800
6,780
71600
4,270
15,800
227
562
4,380
322
Total
Potentially
Hazardous
Wastes
Wet
177
12,200
2r02*
SH
61
6.900
1S4
4.560
6
626
11,260
• Ui
29.600
7,250
S[980
7,380
9.266
3,1!IO
14;CI>0
3
600
5,570
4.620
23.800
151,000
50,100
17.800
6I290
4.680
44.100
626
11.900
2,020
12,200
777
Dry
48
3.620
49fi
18
2.066
51
I,lo6
0
3,420
3!
11.201
1,97' i
1,596
l!666
2,716
185
4,' 20
1
163
l.S8(
1.28C
6.730
45,200
17,300
s.2:c
!^3i^
12,: oo
:.Ss
2.770
49i "
3.626
211
Source:
Note:
SCS Engineers, except production information,which
is from Tanners' Council of America.
Totals may not add due to rounding.
Production is based on the sum of all hides put into
processing at all seven types of tanneries.
8
-------
TABLE 2
TOTAL PROCESS AND POTENTIALLY HAZARDOUS SOLID WASTE
GENERATED BY ALL TY?ES OF TANNERIES IN 1977 (PROJECTED)
(metric tons per year, wet and dry basis)
•••••— ^M~W«^^^^
State (s)
AK.WA
AZ.CA
CO.UT
DE
FL.GA
IL
IN, OH
IA,NE
KY
LA,TX
MEjVT
HD,VA,WV
MA
MI
MN
MO
NH
NJ
NY
NC
OR
PA
TN
WI
Total
Region I
II
III
IV
V
VI
VII
VIII
IX
X
Total
Process
Solid
Waste
Wet
215
14,900
2.581
717
1,840
8,350
1,340
5,840
5^150
908
14,400
13,500
34,600
8,790
7,320
9,600
11,100
3,980
17,600
2,280
964
16,100
8,850
29,300
220,000
60,100
21,600
30,300
18,100
55,100
908
15,440
2,580
14,900
1,180
Dry
68
4,920
689
232
417
2,750
321
1,530
1,140
258
4,600
3,000
14,100
2,760
2,230
2,470
3,700
1,280
6,110
505
281
4,290
1,840
9,550
69,100
22,450
7,390
7,520
3,900
17,600
258
4,000
689
4,920
349
Total
Potentially
Hazardous
Wastes
Wet
220
13,700
2,528
625
68
• 7,440
225
5,700
0
768
12,300
165
33,900
8,040
7,050
8,660
10,300
3,920
17,000
3
749
6,860
5,740
27,500
173,000
56,500
21,400
7,750
5,810
50,250
768
14,400
2,540
13,700
969
Dry
54
4,100
612
180
19
2,240
56
1,380
0
188
3,610
40
12,200
2,210
1,820
2,080
3,000
1,020
5,030
1
183
1,780 .
1,430 ;
7,640
51,000
18,800
6,050
2,000
1,450
14,000
188
3,460
612
4,100
237
Source: SCS Engineers
Note: Totals may'not add due to rounding.
-------
TABLE 3
TOTAL PROCESS AND POTENTIALLY HAZARDOUS SOLID WASTE
GENERATED BY ALL TYPES OF TANNERIES IN 1983 (PROJECTED)
(metric tons per year, wet and dry baaia)
State (s)
AK.HA
AZ,CA
CO.UT
DE
FL,GA
IL
IN, OH
IA,NE
KY
LA,TX
ME,VT
MD,VA,WV
HA
MI
MN
NO
NH
NJ
NY
NC
OR
PA
TN
WT
Total
Region I
II
III
IV
V
VI
VII
VIII
IX
X
Total
Process
Solid
Waste
Wet
287
20,200
4,000
943
1,750
11,100
1,344
9,130
4,870
. 1,350
18,600
12,800
43,300
11,700
10,100
14,600
14,500
5,570
22,900
2,150
1, 200
17,800
10.600
40 100
281,000
76,600
28,500
31,500
19,400
.74,300
1,350
23,700
4,000
20,200
1,490
Dry.
89
6,540
1,053
298
382
3,580
317
2,390
1,030
356
5,860
2,260
17,100
3,640
3,020
3,780
4,720
1,720
7,690
457
348
4,7?0
3,010
12.800
87,700
27,700
9,410
7,800
4,800
23,400
356
6,170
1,060
6,540
437
Total
Potentially
Hazardous
Wastes
Wet
269
19,100
3 a or
77
9,670
269
8,890
0
1,160
17,500
200
24,100
11,000
9,550
13,600
13,700
5,240
21,100
2
912
8,400
7,010
37.60Q
214,000
55,300
26,300
9,480
7,090
68,100
1,160
22,500
3,890
19, 100
1,180
Dry
75
5.600
MS
243
22
3,020
75
2,140
0
283
4,830
55
15,100
3,040
2,560
3,270
3,980
1,440
6,260
1
252
2,410
1,960
10.600
68,200
23,900
7,700
2,700
1,980
19.300
283
5,410
950
5,600
326
Source: SCS Engineers
Note: Totals may not add due to rounding.
10
-------
FIGURE 2
POTENTIALLY HAZARDOUS SOLID WASTE GENERATED IN 1974
Legend (metric tons/yr
wet weight basis)
0
0-1,000
1,000-10,000
10,000-20,000
20,000-30,000
-------
It is also worth noting that a comparison of Figure 1
and 2 indicates a general correlation between the number of
tanneries in a state and the quantity of potentially
hazardous solid wastes generated. Variations from this
general relationship occur principally due to concentrations
of vegetable tanneries (which do not generate potentially
hazardous wastes) and leather finishers (which generate
relatively small amounts of potentially hazardous wastes),
e.g., Pennsylvania and New York.
Chromium (III) is by far the most abundant potentially
hazardous constituent found in tannery wastes. Lead, copper,
and zinc are also present in the wastes. Estimates of the
nationwide total quantities of these heavy metals generated
in tannery wastes is shown below:
Potentially hazardous constituents
(metric tons per year)
Chromium (III) Zinc Lead Copper
1974 909 0.46 10.6 16.9
1977 1,000 0.59 11.9 19.6
1983 1,300 0.94 14.7 28.0
1.3.2 Potentially Hazardous Wastes. "Potentially
hazardous wastes" are defined as wastes or combinations of
wastes, which pose a substantial present or potential future
hazard to human health or living organisms because such
wastes are lethal, non-degradable, or persistent in nature;
may be biologically magnified; or otherwise cause or tend
to cause detrimental cumulative effects.3
Many of the substances of particular concern in this
study, primarily heavy metals, are prerequisites to life in
trace quantities, but are toxic at higher concentrations.
The uncertainty and confusion about what concentration levels
are hazardous arises because:
In the complete absence of certain elements, life
cannot exist.
. There is a vaguely defined intermediate concentration
range in which these substances are essential and/or
can be tolerated.
There is a higher level above which chronic and
acute toxicity may result.
Definition of Potentially Hazardous Haste. Scientific
studies of the environmental fate of tannery wastes following
land disposal have not been conducted, and in many instances
the chemical structure of tannery solid waste is not well
understood. As a result, it was necessary to select a
12
-------
recognized reference for identifying the concentration level
above which the presence of a hazardous constituent in
tannery waste makes the waste potentially hazardous. As
a guide as to what constitutes potentially hazardous
concentration levels in wastes destined for land disposal,
the geometric means of the background concentration levels
in soils in the United States of the toxic heavy metals
found in tannery wastes were used as the reference datum.4
Using this definition in conjunction with analyses of
tannery waste samples, the types of tannery wastes which
should be considered potentially hazardous were identified.
Table 4 lists the various types of potentially hazardous
wastes; the hazardous constituents present in each type
at concentration levels above the mean concentration in
soils; the results of tannery waste sampling and analyses;
and the relevant background soil values. As shown, four types
of tannery waste were identified which contain four hazardous
constituents at potentially hazardous concentration levels,
one type of waste with three hazardous constituents, one
type of waste with two hazardous constituents, and two types
of waste with a single hazardous constituent. Analyses were
made for other heavy metals, pesticides, and phenols; however,
none were found at potentially hazardous concentrations.
Several types of wastes which are not considered
potentially hazardous were also identified. Plant floor
sweepings and related miscellaneous solid waste were found
to be non-hazardous in all types of tanneries. In vegetable
tanneries, all types of solid waste generated are considered
non-hazardous since hazardous constituents were not found
at concentrations above the mean soil concentration. For
example, copper was found at an average concentration of
13.4 ppm (dry weight) in wastewater treatment residues from
four vegetable tanneries, whereas the geometric mean
concentration in U.S. soils is 18 ppm (dry weight).
Discussion of Potentially Hazardous Wastes. Although
the environmental effects of lead, zinc, and copper are
not completely understood, the phototoxicity of zinc and
copper to agricultural crops, the toxicity of lead to man,
and the toxicity of all three elements to various aquatic
organisms, is well established.
The only form of chromium of concern and interest in
this study is trivalent chromium, since other forms of
chromium are not used in the production of leather. The
toxicological information on trivalent chromium, however, is
conflicting. Some information is available on the
effects of trivalent chromium on plants which generally
indicates that low concentrations of trivalent chromium may
be essential, or possibly even beneficial, whereas higher
concentrations may be toxic. The effects vary with species
and with the specific chromium compound. The effects on
plant growth of adding chromium to the soil depend upon the
13
-------
7&3LE 4
POTENTIALLY HAZARDOUS TANNERY WASTES
Analytical Results
Waste Stream
Ho. of
Sample*
Hazardous
Constituent*
Concentration
(wot weight-
•g/lcg)
Concentration
Range*•
(wet weight-
s/kg)
Geometric Mean
Concentration in
U.S. Soils (dry
weight-mg/kg)
Chrome (blue) 10
trimmings «
shavings
Chrome fleshings 1
Unfinished chrome 9
leather trim
Buffing dust 12
Finishing residues 16
Finished leather
trim
,+3
Cr
Cr
Cu
Pb
Za
Cr*3
Cu
Pb
Za
Cr+3
Cu
Pb
Za
Cr
Pb
.+3
7,«00
4,000
16,900
90
120
60
5.700
960
ISO
160
3,300
40
8,400
ISO'
14,800
1,000
2,200-21,000
4,600-37,000
2.3-468
2.5-476
9.1-156
19-22,000
29-1,900
2-924
0.45-12.000
0.35-208
2.5-69,200
14-876
1,600-41,000
100-3,300
37
37
37
18
16
44
37
18
16
44
37
18
16
44
37
16
Sewer screenings
17
Pb
Sa
2,200
30
60
0.27-14,000
2-110
35-128
37
16
44
Wastewater treatment 27
residues (sludges)
Cr
Cu
Pb
Zn
+3
3,700
370
60
50
0.33-19,400
0.12-8,400
0.75-240
1.2-147
37
18
16
44
Sourcet Laboratory analytical results and Reference 21
Rote i Since tannery wastes are land disposed in a wet condition, i.e.,
containing moisture, reporting constituent concentrations on a
wet weight basis realistically portrays the waste streams'
chemical characteristics with respect to hazardous constituents.
Constituent concentrations in U.S. soils were not available on a
wet weight basis. Geometric mean values on a wet weight basis would
be slightly less than those reported above. Thus the method of
reporting the concentrations (wet or dry basis) does not impact
on the designation of a waste stream as non-hazardous or potentially
hazardous.
• For which analyses were made.
•• Range not shown when only one sample was analysed for the constituent.
14
-------
amount of chromium naturally present in the soil. In some
instances, crop yields have been improved by application of
chromium to soils; conversely, a number of observations have
been made of toxic effects of trivalent chromium on orange
and corn seedlings, oat and corn plants, and tobacco.4»5,6,7,8,9
Similarly, trivalent chromium has been reported in the
literature as toxic to a variety of aquatic species, including
sticklebacks, flathead minnows, polycelisnigra (flatworm),
Daphina and young eels.6'9 However, recent attempts to
repeat some of the earlier studies regarding the toxicity
of trivalent chromium to sticklebacks and other fish have
concluded that pH and/or the solubilizing agents used were
the cause of the reported toxicity.8
As the preceding paragraphs have indicated, the existing
information on the toxicity of trivalent chromium to plants
and aquatic organisms is contradictory in many instances.
However, trivalent chromium could ultimately be leached from
tannery wastes, and since it is reported by some researchers
as being toxic to various plants and aquatic organisms,
trivalent chromium is considered to be a hazardous
constituent of tannery solid waste.
1.4 Treatment and Disposal Technology
1.4.1 Treatment. Sludges from wastewater pretreatment/
treatment facilities are the only potentially hazardous
wastes which are currently treated prior to disposal.
Treatment consists of dewatering the sludges. The only
categories of tanneries with such facilities are the complete
chrome tanneries and the beamhouse/tanhouse facilities. This
is due to the fact that the beamhouse is the major source
of suspended solids in a tannery.
Sludge dewatering is accomplished using gravity (sequential
settling) or mechanical means. Three mechanical methods of
sludge dewatering are used by tanneries—vacuum filters,
centrifuges, and filter presses. All three are effective;
however, there seems to be a preference for filter presses
due to the slightly drier (40 percent solids) filter cake
produced. Gravity dewatering systems are also used to a very
limited extent, but the prevalence of this method of treatment
appears to be declining. One of the largest gravity dewatering
systems has recently been replaced with a filter press.
As restrictions on the wastewater discharges from tanneries
become more stringent, more tanneries will install wastewater
pretreatment facilities. This will lead to more widespread
use of mechanical dewatering of the sludge generated. The
complete chrome tanneries and the beamhouse/tanhouse facilities
will be the two types of operations most likely to install
sludge dewatering equipment.
15
-------
Sludge dewatering is the only type of solid waste
treatment applicable and appropriate for tannery wastes.
No exotic treatment such as detoxification or chemical
fixation is considered necessary.
1.4.2 Disposal. Approximately 60 percent of potentially
hazardous tannery waste is disposed in landfills. "San if .try
landfills" (as defined by FPA which provide for engineered
disposal and daily cover) accept 10 percent of the potentially
hazardous tannery waste. Engineered landfills which do not
provide daily cover accept about 25 percent of the waste. The
remaining landfills are converted dumps. Open dumps accept
about 25 percent of the waste. Dumps are most common in EPA
Region I and are normally municipally owned. Most of these
are being closed or converted to landfill operations.
Potentially hazardous waste (including sludge) is usually
mixed with municipal refuse, compacted, and covered. At
some disposal sites, wastewater treatment sludge is segregated
and placed in trenches or lagoons. Operational problems
include some reported difficulty in spreading and compacting
large quantities of waste (particularly blue trimmings and
shavings) that are mixed with municipal refuse.
Leaching of the heavy metals from potentially hazardous
waste is the primray environmental concern associated with
landfilling. A secondary problem is the flammability of some
finishing residues; however, only small quantities of this
waste are disposed at any one time.
The more advanced disposal technologies for potentially
hazardous waste examined during site visits included lined
trenches for wastewater pretreatment/treatment sludge, and
State-certified hazardous waste dipsosal facilities.
Tanneries normally use the least expensive site
available—normally a municipally-owned landfill or dump.
Tannery-owned facilities are usually operated because of the
plant's remote location or the fact that other disposal sites
will not accept the waste (usually sludges). It is estimated
that only 10 percent of all tanneries operate their own
disposal sites.
Industry treatment and disposal technologies are
classified herein as Level I, Level II, or Level III. Level
I is the most common practice currently employed. Level II
is the best technology currently employed. Level III
treatment and disposal technology is that which provides
adequate health and environmental protection. The
technologies for these three levels of treatment and disposal,
and the quantities and percentage of wastes going to each
level of technology, for the six tannery categories generating
potentially hazardous wastes are shown in Table 5. As indicated.
Level III technology is currently (1974) used only in two
categories of the industry, and only in situations where
Level II and Level III are the same. Using the data in
16
-------
TABLE 5
THP.ATMENT AND DISPOSAL TECIWOMXSV LEVF.tS AND
ASSOCIATED POTENTIALLY HAZARDOUS WASTE OUAMT1TIES
Category
Coxploto chrome
tannery
Sheepskin
tannery
Split tannery
Leather finisher
Beanhouso/
tanhouse
facility
Rotan/flnahor
Troatmont/Dlsoosal Technolotv
" Kvel 1 '
Landfill
Landfill
Dump
Landfill
Dewaterod
sludge,
disposed
In lund-
fill
Landfill
1 l.c veil I!
Dewater sludge.
all waste
disposed in
certified
hazardous waste
disposal
facility
Landfill
Landfill
Landfill
Countered
sludge
disposed in
11 nod tranches
Landfill
Lovol III
Sane as Level
II, landfill
with loaehato
collection
Landfill with
leachato
collection
Landfill with
leachato
collection
Landfill with
loachate
collection
Same as Level
II, or landfill
with lonchnte
collection
Landfill with
loachnte
collection
Current (1974) Distribution of Haste Cctwoon
Treatment/Disposal Tcchnolonipii
E.uvcl'1 "
metric tona/yr,
(w«t/dry)
52,000/14,000
2,500/800
11,200/5.500
540/180
12,600/3,000
2,500/1,300
1
50
CO
70
60
60
55
Loviil 11
metric tons/yr
{wot/dry>
4,200/1,200
2,500/800
4,800/2.400
540/180
4,300/1,000
2.500/1,300
I
4
60
30
60
20
55
LCVv'l 11.
metric tons/yr
(wot/Jry)
4,200/1,200
0
0
0
4,200/1,030
0
V
<
0
0
0
20
0
Source: SCS Engineers
-------
Table 5 and correcting for the overlap between technology
levels, it is estimated that 85 percent of tannery potentially
hazardous waste is going to Level I technology, 10 percent
to Level II, and 5 percent to Level III.
1.4.3 Alternatives to Disposal.
Municipal Sewage Treatment. Some tanneries are located
in communities where most of the wastewater received at the
municipal sewage treatment plant is discharged by tanneries.
These situations are somewhat unique to the tannery industry
and deserve mention.
This situation is particularly prevalent in New England
(EPA Region I), where three tanneries were visited which
provided 80 to 95 percent of the flow to municipal treatment
facilities. In other New England and New York (EPA Region II)
communities, up to 60 percent of the flow was contributed by
tanneries. Thus, the municipalities were essentially treating
tannery wastewater and generating and treating tannery sludge.
In the community in which the tannery contributed
95 percent of the flow, the primary treatment plant sludge was
dewatered using centrifuges and disposed in trenches at the-
city's landfill. In the two other communities visited, the
tanneries contributed about 80 percent of the flow. Both of
the treatment plants were constructed recently and neither
was producing any secondary sludge. Primary sludge was
dewatered with centrifuges. One operation was disposing
of the dewatered sludge in trenches, and the other treatment
plant was stockpiling the sludge near the plant until a
disposal site was found.
Source Reduction Through In-Plant Process Changes.
There are several in-plant processing changes in use by
varying numbers of tanneries. These changes primarily
contribute to economic advantages and secondarily impact on
waste generation. These processes are in various stages of
development from experimental through pilot plant and full
scale operation. However, none of the processes are in
widespread use in any of the tannery categories, let alone
the tanning industry as a whole.
It is doubtful that many of the in-plant processes
will come into widespread use by 1983. The impression
gathered from tannery officials during the course of this
project was that tanning is considered an art. Each tanner
feels that he knows the "tricks of the trade" as far as the
production of his particular leather is concerned. Tanners
strive to maintain a quality product of consistent color,
texture, pattern, etc., in order to retain their established
customers. Some tanners are not sure that they can reduce
their chemical usage, use reformulated finishes, reuse
chrome, etc., and still produce the same product, and thus
18
-------
are reluctant to make even minor changes in their processing.
Therefore, tanners will move slowly in altering their
processing procedures. Since the in-plant process changes
are not applicable to nor likely to be adopted by all
tanneries in a particular category, no attempt has been made
to suggest them to the entire industry. Consequently,
in-plant process changes which impact on the quantity or
nature of potentially hazardous waste have not been included
as any level of treatment/disposal technology.
Sale as By-products. Economic feasibility is currently
the primary factor affecting by-product utilization of
potentially hazardous waste. Following is a list of the
types of potentially hazardous wasteswhich are currently
saleable and by-product uses:
Waste stream
Blue trim and shavings
Solvent-based finish
residues
Leather trimmings
By-product use
Fertilizer
Hog feed supplement
Glue
Solvent recovery
Glue
Craftsman—small leather
articles
With the exception of solvent recovery, by-product
utilization of potentially hazardous waste is volatile and
dependent upon location. The major type of potentially
hazardous waste sold is blue trim and shavings. These
are, and have been, sold to producers of fertilizer, animal
feed supplements, and glue. These markets are apparently
declining as evidenced by the fact that, within the last
two decades, the number of fertilizer producers utilizing
leather waste has been reduced from 28 to 3. In addition,
glue manufacturing from leather waste has essentially ceased.
However, tanneries located in the Midwest are able to sell
their blue trim and shavings to a producer of fertilizer
used principally in citrus groves and to a lesser extent
in other orchards. Similarly, some tanneries also sell blue
trim and shavings for use as a hog feed supplement. If
possible, finsihed leather trimmings are sold to local
craftsmen or foreign countries for the manufacturing of
small leather goods.
Sale of potentially hazardous waste for by-product'
uses is encouraged as an alternative to disposal if the
ultimate use of the waste is environmentally sound. Blue
trim and shavings are considered potentially hazardous due
to their high trivalent chromium content. Information in
the literature indicates that trivalent chromium is hazardous
to aquatic organisms and to lower forms of terrestrial plant
19
-------
life, but not to mammals and higher plant forms. Consequently,
the use of blue trim and shavings as a hog feed supplement
is approved by the U.S. Department, of Agriculture (chromium
content not to exceed 275 ppm). Similarly, the use of this
waste as an. orchard fertilizer can be beneficial as long
as the application does not become excessive and ground
and surface water pollution does not result from the practice.
Use of the waste for other fertilizer applications, such
as vegetable crops, must be studied further before the
environmental adequacy of the practice is known.
1.5 Cost Analysis
The cost data presented in this report is based upon
actual costs reported by tanneries, and from prices quoted
by disposal contractors serving tanneries. As necessary,
additional informationis included from equipment suppliers,
published literature, government sources, and SCS files.
All cost information is given in December 1973 dollars,
and when necessary, have been adjusted to this basis using
the Chemical Engineering (CE) Plant Cost Index. For
purposes of comparing the total cost of potentially hazardous
waste treatment and disposal for the tanning industry to the
value added in manufacturing and the total value of shipments,
the latter indicators were converted to December 1973 dollars
using the wholesale price index furnished by the Bureau
of Labor Statistics.
1.5.1 Treatment. Sludges resulting from primary and/or
secondary wastewater treatment at beamhouse/tanhouse facilities
and some complete chrome tanneries are the only solid waste
generated- by the leather tanning industry which is treated
prior to disposal. The only treatment is dewatering, and it
is always conducted on-site.. The annual cost for sludge
dewatering at a typical complete chrome tannery with primary
and/or secondary wastewater treatment or a typical beamhpuse/
tanhouse facility generating 10,000 kg of dewatered sludge
per 1000 equivalent hides processed is $86,000 per year.
1.5.2 Disposal. All of the typical plants- for the
six categories of tanneries which generate potentially
hazardous solid waste utilize contractor service for hauling
and disposal. .Contractor hauling and disposal charges range
from $2 per metric ton of waste for open dumping to $46
per metric ton for a State-certified hazardous waste disposal
facility,-depending upon the type of disposal utilized,
the quantity of waste generated by a particular plant, and
the type of waste. Landfill disposal of potentially
hazardous waste is the most common disposal method in this
industry, and costs a typical tannery $10 per metric ton'.
20
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1.5.3 Summary and Discussion. A summary of the cost
estimates for the three levels of treatment and disposal
technology for typical plants in the six categories of
tanneries is presented in Table 6. As shown, there are
significant differences in cost for the typical plants of
the different categories of tanneries. These variations
are due to a variety of factors, including:
Plant production.
Contractor hauling and disposal costs.
Local and geological conditions.
Urban or rural location.
Equipment used.
Individual plant production varies widely for plants within
a given category, especially for complete chrome tanneries,
where the largest plant is more than 100 times as large as
the smallest plant. For tanneries generating relatively
small quantities of solid waste (a few hundred kilograms
daily), the cost of solid waste treatment and disposal per
metric ton of waste is approximately three times that of
plants which generate quantities more typical of operations
in most of the categories (more than one metric ton per day).
The other factors mentioned above are all site specific
considerations, and estimation of changes in cost must be
made on a case-by-case basis.
As shown, the total annual cost for Level I and Level
III is the same for a typical complete chrome tannery without
primary and/or secondary wastewater treatment. Although
the cost per metric ton of waste is higher for Level III,
due to higher costs for disposal in a landfill with leachate
collection, the total cost is the same since Level III
assumes that trimmings and shavings are sold as a by-product.
For a complete chrome tannery with primary and/or
secondary wastewater treatment, the total fixed cost is
due entirely to sludge dewatering. Sludge dewatering accounts
for approximately 90 percent of the increase in total annual
cost for complete chrome tanneries with primary and/or
secondary wastewater treatment, relative to complete chrome
tanneries without wastewater treatment facilities. The
other 10 percent of the increase in costs is the result of
sludge disposal charges.
Two different Level III treatment and disposal
technologies are shown for split tanneries. The more
expensive Level III technology (Alternative 1) is based on
disposal of the waste in a landfill with leachate collection.
The less expensive Level III technology (Alternative 2)
costs are based on the sale of trimmings and shavings and
the disposal of other potentially hazardous waste. The
large difference in the total cost of these two alternatives
arises because blue trimmings and shavings represent 90
21
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TABLTS 6
M
M
Category
Complete Chrome
Tannery, without sludge
(Production - 26o7oOO
equivalent hides/year)
Complete Chrome
Tannery wi^h sludge
(Production - 2(0,000
equlvalmt *4«>«/»M«>
Sheepskin Tannery
(Production - 200,000
equivalent hides/
y«e*)
Cost Item
Total Fixed
Total Annual
Cost/1000 equivalent
hides
Cost/metric tea of
waste*
Total Fixed
Total Annual
Cost/1000 equivalent
hides
Cost/metric tea of
waste*
Total Fixed
Total Annual
Cost/1000 equivalent
hides
Cost/Mtric ton of
waste*
Level Z
(S)
None
13,000
40
10
304,000
119,400
451
37
None
0,700
34
20
Level ZZ
(S)
None
10,000
30
10
304,000
131,000
504
46
Voae
6, .700
34
30
Level ZZZ (5)
Alt. 1
None
13,000
46
14
304,000
131,000
504
46
None
0,100
40
24
Alt. 2
—
...
...
•..
304,000
125,500
402
44
...
—
.—
...
-------
to
TABLE 6
(Continued)
Category
Split Tannery
(Production = 400,000
equivalent hides/
year)
Leather Finishers
(Production » 225,000
equivalent hides/
year)
Cost Item
Total Fived
Total Annual
Cost/1000 equivalent
hides
Cost/metric tons of
waste*
Total Fixed
Total Annual
Cost/1000 equivalent
hides
Cost/metric ton of
waste*
Level I Level II Level III ($)
($} ($} Alt. 1 Alt. 2
None None None None
7,000 3,600 48,000 4,300
17 9 121 11
2 20 14 24
None 'None None
1,100 1,100 1,500
4.9 4.9 6.6
31 31 41
Beamhouse/tanhouse
facility
(Production = 300,000
equivalent hides/
year)
Total Fixed
Total Annual
Cost/1000 equivalent
hides
Cost/metric ton of
waste*
304,000 304,000 304,000 304,000
115,800 121,800 121,800 129,800
390
38
406
41
406
41
426
43
-------
TABLE 6
Category
tetan/finianef
(Production • 675,000
equivalent aidoa/
year)
. Coat Xten
Total Fixed
Total Annual
Coat/1064 equivalent
hidee
Coat/aetrio ten of
vaate*
Laval X
t$)
Bone
12,000
18
10
Laval XX
IS)
Bone
8,000
12
20
Laval XXX
($)
Alt.- 1 Alt. 2
Bone
17,000
25
14
Bone
9.000
1)
24
I SCS Inginaara
• Vet voifkt aeaiav
-------
percent of the waste generated by a typical split tannery.
The cost per metric ton of waste actually disposed for
Alternative 2 is increased due to the substantially reduced
quantity of waste which must be collected and disposed.
A typical leather finisher generates less solid waste
than any other type of tannery. Consequently, the annual
contract hauling and disposal costs for all three
levels of technology are less than for any other categories.
However, the cost per metric ton is higher than for most
other categories due to the small volumes of waste which must
be collected and disposed.
Since wastewater treatment sludge is the only potentially
hazardous waste generated by a typical beamhouse/tanhouse
facility, all costs shown are the result of treatment and
disposal of sludge. The cost of treatment and disposal for
the most expensive Level III (Alternative 2) is only about
10 percent higher than for Level I. However, since about 90
percent of the total annual cost is the result of sludge
treatment, which is the same for all levels of technology,
the percentage increase in total cost to go from Level I
to Level III technology is not very substantial.
Table 7 summarizes the total costs of treatment and
disposal for each category of tannery and illustrates
the differences in costs discussed above. For complete
chrome tanneries with primary and/or secondary treatment
sludge, approximately 90 percent of the total annual
treatment and disposal costs are the result of wastewater
treatment sludge. For beamhouse/tanhouse facilities, 100
percent of the treatment and disposal costs are the result
of wastewater treatment sludge. As a result, approximately
65 percent of the cost of treatment and disposal for the
total industry for all three technology levels is a result
of wastewater sludge dewatering and disposal. For complete
chrome tanneries without primary and/or secondary wastewater
treatment sludge, the total annual treatment and disposal
costs for all levels of technology are substantially
higher than for other categories such as sheepskin, split
tanneries, retan/finishers and leather finishers because
the production of the complete chrome category is many times
larger.
Another important factor effecting the cost of treatment
and disposal technology for the total industry is the ability
of complete chrome tanneries (without primary sludge), retan/
finishers, and split tanneries to sell trimmings and shavings
as a by-product. For these three categories of tanneries,
the cost of treatment and disposal is less for Level II
(with sale) than Level I (without sale), with the result
that the total cost to the industry of Level I technology is
virtually the same as for Level II. Similarly, the difference
in cost between the most and least expensive Level III
technology is primarily a function of whether trimmings and
shavings are sold or land disposed.
25
-------
ANNUAL TRBATKBMT AMD DISPOSAL COSTS
(00e. 1973 dollars)
Tannery
Category
Chrome «/
sludge
Chrome v/o
sludge
Sheepskin
Split
Leather
finisher
Beamhouse/
Tanhouse
Facility
Retail/
Finisher
Total
Level I
1,524,000
675,000
84,000
60,000
27,000
812,000
37,000
3,219,000
Level IX
1,702,000
519,000
84,000
31,000
27,000
•54,000
25,000
3,242,000
Lew
Least costly
1,629,000
•75,000
101,000
37,000
37,000
•54,000
28,000
1,361,000
il III
Moaft costly
1,702,000
675,000
101,000
411,000
37,000
896,000
53,000
3,875,000
Source: SCS Engineers
26
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Using the distribution of production between the
various categories observed in 1974, the value added in
manufacturing (in December 1973 dollars) during 1974 was
$480 million, and total value of shipments was $1,010
million. Thus, the costs of the three levels of treatment
and disposal technology compared to the value added in
manufacturing and the value of shipments are as follows:
Treatment and Treatment and
disposal cost— disposal cost—
percent of value percent of value
Technology level added of shipments
I 0.67 0.32
II 0.68 0.32
III (least costly
alternatives) 0.70 0.33
III (most costly
alternatives) 0.81 0.38
Thus, it appears that there is little difference in
the overall costs between Level I and Level III technologies
(Table 7) and also in relative costs as percentages of
value added and value of shipments (as tabulated above)-
These figures are industry-wide averages, and the impact on
individual tanneries may be quite different than shown.
27
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SECTION 2.0
INDUSTRY CHARACTERIZATION
2.1 The Tanning Industry
2.1.1 Introduction to Tanning. Tanning, one of the
oldest arts known to man, is the process of converting the
skins and hides of animals into leather. Pictures carved
by Egyptians over 5,000 years ago depict tanning operations.
The Greeks had developed leather making into a well
established trade by the year 500 BC and in the 12th
century, tanners' guilds were organized in England and
Europe to regulate the manufacturing processes and advance
the art of leather making.10
Tanning involves a complex combination of mechanical
and chemical processes. The heart of the process is the
tanning operation itself in which organic or inorganic
materials become chemically bound to the protein structure
of the hide and preserve it from deterioration. The substances
used to accomplish the tanning process for viturally all
of the leather produced in this country are chromium or
extracts from the bark of trees, such as chestnut. These
tanning agents give rise to the two "predominant types of
tanning operations—chrome and vegetable tanning.
Chrome Tanning. Approximately 85 percent of the
leather produced in this country is chrome tanned.2 Chrome
tanning produces leather better suited for certain applications,
particularly for the upper parts of boots and shoes, and
requires less processing time than traditional vegetable
tanning.
While cattlehides are the most common raw material
for chrome tanning; sheepskins, calfskins, pigskins, and
other hides and skins are tanned in this manner. It should
be noted that the terms "hides" and "skins" refer to the
entire skins removed from an animal and used as a raw material
for tanning. "Hide" is used for large animals, e.g.,
cattlehide, horsehide. "Skin" is used for smaller animals,
e.g., pigskin, sheepskin, calfskin. The term "hide" will be
used hereafter unless a specific type of hide or skin is
being discussed.
The general steps required for chrome tanning of leather
are shown in Figure 3 and described briefly below. No two
tanneries are identical; each has its unique characteristics
and subprocesses; some perform only some of the processes
shown and ship their goods to another tannery to complete the
processing. The following description is intended to be
illustrative and to provide the layman with a general
29 Preceding
-------
FIGURE 3
TYPICAL TANNING PROCESS STEPS
CHROME TANNING
VEGETABLE TANNING
HIDES RECEIVED
| SOAKING |
(FLESHING)
1
I LIMING |
^
t
BATE
PICKLE
TAN
I SPLIT AND SHAVE\
RET AN
COLOR
FATLIQUOR
DRY
MECHANICAL
CONDITIONING
[FINISHING)
MEASURING AND
PACKAGING
IHIDES RECEIVED
[ LIMING
1
[MECHANICAL HAIR REMOVAL
--
[FLESHINGJ
[MECHANICAL CONDITIONING]
1
[MEASURING AND PACKAGING)
30
-------
understanding of the major processing steps.
Hides and skins are received from meatpacking plants
by truck or railroad car. Each cattlehide is tied in a
bundle weighing approximately 25 kg. The bundles are cut
open and the hides unfolded, inspected, and usually split
along the backbone, producing two sides from each hide.
Next follows a sequence of wet operations. The sides
are soaked in water to return some of the lost natural
moisture. The remaining flesh or fatty substance adhering to
the inside or flesh surface of the side is removed; these
fleshings are usually either rendered in the tannery or sold.
The cattlehides are then soaked in a lime and sulfide solution
which either loosens or dissolves the attached hair. In some
operations, the hair is only loosened through the caustic
action of the lime with the hair removed mechanically,
followed by washing, drying, and sale as a by-product (for
carpet pads or similar uses). However, the more common
approach for hair removal is to completely dissolve the hair
and discharge it to the wastewater stream.
Following hair removal, the hides are ready to be
prepared for the actual tanning operation. The hides are
placed into large rotating drums and are treated in turn with
an enzyme solution and then a salt-acid solution,, These
operations (called bating and pickling respectively) prepare
the hide for the tanning process. While still in the drum
after the discharge of the pickling solution, the hides are
tanned. A chromium sulfate solution is added to the drum
and the hides and chrome solution are mixed for periods of
up to 24 hours.
Following chrome tanning, all hides have a characteristic
blue color caused by the chrome tanning solution. Upon
removal from the tanning drums, excess moisture is removed
from the hides through a wringing operation.
Cattlehides are too thick for most purposes and therefore
the tanned hides are split, using a machine similar to a
horizontal band saw. The splitting operation produces a
grain side of more or less uniform thickness. One surface
of this grain side is the original outer surface of the
cattlehide and retains the natural grain. The splitting
operation also yields a thin, inner portion of the hide
known as a "split" or "blue drop." Splits have no graining
and are often used for suede garments. Both the grain side
and the split may be further processed to form a piece of
material of uniform thickness. This operation is called
shaving and results in the removal of small pieces of leather
with a consistency similar to very coarse sawdust.
Another series of wet operations gives the leather the
color and other properties desired in the finished material.
The tanned hides are placed into another drum for retanning,
coloring and fatliquoring. Retanning is a second, shorter
31
-------
tanning operation normally using a tanning agent other than
chromium. After the retanning solution is discharged from
the drum, a pigment is added in order to dye the leather to
the desired color. The coloring solution is also discharged
from the drum. Next a mixture of oils is added and the
hides and oil are rotated in the drum. This operation, called
fatliquoring, helps to produce the desired softness.
After removal from the retan, color, and fatliquor
drum, the leather is dried and physically conditioned. The
two most common approaches to this conditioning are staking
and buffing. Staking is a form of massaging which makes
the leather more plyable. Buffing is a light sanding
operation applied to either the grain surface or the underside
of a piece of leather. It is used to improve the nap of the
underside or to smooth out surface imperfections on the grain
surface.
One or more of several possible finishing steps are
then accomplished to give the leather the required pattern
gloss, or waterproof qualities. Usually all leather receives
at least one coat of a liquid finish material. Finishes are
either rolled or sprayed onto the leather. These operations
are followed by drying. Often three or more coats of finish
are applied to leather; each is followed by a drying cycle.
Other finishing operations include embossing, in which
patterns are pressed into the leather surface. Finally, the
surface area of each piece of leather is measured electronically
and the area stamped on the underside. The leather is then
packaged and stored for shipment.
Vegetable Tanning. Vegetable tanning employs the use
of extracts from the bark of various trees as the tanning
agent. Since the introduction of chrome tanning, vegetable
tanning has decreased in importance. Soles of shoes have
been traditionally vegetable tanned; however, since the
introduction of synthetic materials for shoe soles, vegetable
tanning has further decreased in importance. Vegetable tanning
is the process by which most leather shoe soles are tanned,
and it is also used to produce leather used in crafts.
Many of the basic steps used in the chrome tanning
process are also present in vegetable tanning. The sequence
in which these steps are employed is somewhat different, and
there are few finishing operations associated with vegetable
tanning. A processing diagram for vegetable tanning is
also shown in Figure 3.
The processing of hides prior to vegetable tanning begins
with a soak in a lime solution to loosen the hair. Hides are
then removed from the lime solution and the hair removed
mechanically. The hides are then soaked and rinsed, and the
fleshing operation is accomplished. Note that in the chrome
tanning process, fleshing preceded the hair removal operation.
32
-------
After fleshing, the hides are trimmed into a roughly
rectangular shape and then passed through a bate and pickle
operation similar to that used in the chrome tanning process.
Coloring, the next operation, is often done utilizing a weak
tanning solution. Normally vegetable tanned leather is not
highly colored. After coloring, the hides are placed into
vats containing the bark extract tanning solution and moved
from a strong tanning solution to a slightly weaker one,
then rinsed and partially dried.
True splitting is not usually a part of the vegetable
tanning process; however, an operation called leveling is
used to produce a uniformly thick piece of leather. Leveling
removes only the thickest portions of the underside of the
hide, and no "split" is produced. Next, the hide is oiled,
which is a process similar to the fatliquoring in chrome
tanning. Following oiling, the hide is dried and then
mechanically conditioned.
Virtually no finishing is done at vegetable tanneries.
Few, if any, spray finishes are applied and often the only
finishing process employed is pressing to yield a smooth grain
surface. Finally, the hides are measured, packaged, and stored
prior to shipment.
2.1.2 Background.
History in the United States. Tanning is one of the
oldest arts known in this country. Early explorers and
colonists noted that the Indians knew and practiced the art
of leather tanning. Early colonial tanneries were begun
in the New England States in the 1600's. Shortly after
colonial times, tanneries continued to be established in the
New England States and also in rural locations close to the
source of the bark necessary for the tanning solutions. During
the 19th and 20th centuries, tanneries moved west following
the westward movement of cattle. Today, leather tanning and
finishing plants are located in 34 states. However, tanneries
are still concentrated in their traditional areas of New
England and the Middle Atlantic States.2
Magnitude of the Industry. For the purposes of this
report, there are 298 different establishments in the leather
tanning and finishing industry which have production facilities.
This is 219 less than the number reported by the Bureau of
the Census.1 The difference arises from the accounting methods
used by the Bureau of the Census and from interpretation as
to which operations constitute actual production activity.
First, the Bureau of the Census data includes 76 converters.
These operations were not included as part of this industry
study because the converters have no production facilities.
They perform such functions as warehousing, contract measuring,
33
-------
and shipping. A second difference concerns small operations.
Establishments with one to four employees are usually
considered to be taxidermists or hobbyists and are not truly
part of the leather tanning and finishing industry. Finally
those companies conducting two or more activities from the
same location and other instances (not counted as converters)
where no production facilities exist were eliminated. The
Bureau of the Census requires reports from companies engaging
in different lines of activity at one location. This
duplication has been eliminated. Similarly, one-man sales
offices and the like were subtracted from the Bureau of the
Census figures. An alphabetical listing of the remaining
establishments, including their name and address, is included
as Appendix A.
Tanneries tend to be small when measured by the number
of employees. As noted above, the smallest operation
considered to be a viable part of the industry has at least
five employees. The largest plant in the industry employs
about 500 workers. Only 87 plants employ more than 100
workers.*
The facilities in which tanning operations are conducted
tend to be old. The majority of the plants are more than
50 years old, and few completely new plants have been built
in the last two decades.2 The age of plants in the tanning
and finishing industry is distributed as follows2:
Age of plant Percent of plants
Less than 10 years 1
10 to 14.9 years 1
15 to 19.9 years 3
20 to 29.9 years 4
30 to 50 years 18
Over 50 years 67
Data not available 6
TOO
Production in the tanning industry is normally measured
in terms of equivalent hides. An equivalent hide has an area
of 3.7 m2 (40 ft2). Production in 1974 by state is shown in
Table 8. In order to protect the confidentiality of
production information, states are combined when there are
less than three tanneries in a state. As shown, Massachusetts
has the most production, followed by Wisconsin and New York.
The total production of 35.7 million equivalent hides represents
the sum of the hides processed by the seven types of tanneries
discussed in Section 2.2.6. Cattlehides accounted for
approximately 90 percent or 32.1 million equivalent hides
with the remaining 3.6 million made up of sheep, pig, and
calfskins and all others.z
34
-------
TABLE 8
1974 TANNERY PRODUCTION BY STATE
Production
(thousands of equivalent hides
State(s) put into processing)
Alaska, Washington 28
Arizona, California 1,870
Colorado, Utah 220
Delaware 230
Florida, Georgia 169
Illinois 1,630
Indiana, Ohio 200
Iowa, Nebraska 512
Kentucky 437
Louisiana, Texas 107'
Maine, Vermont 2,630
Maryland, Virginia, West 1,150
Virginia
Massachusetts 8,270
Michigan 1,150
Minnesota 393
Missouri 774
New Hampshire 1,670
New Jersey 1,340
New York 4,020
North Carolina 211
Oregon 115
Pennsylvania 1,860
Tennessee 1,230
Wisconsin 493
Total 35,700
Region
Source :
Note:
I
II
III
IV
V
VI
VII
VIII
IX
X
12,600
5,370
3,240
2,040
8,850
107
1,290
221
1,870
143
Tanners' Council of America
Totals
may not add due to rounding.
35
-------
Value of shipments is another indicator of the magnitude
of an industry. The Bureau of the Census reports the value
of shipments for the leather tanning and finishing industry
in 1967 as $846 million and in 1972 at $1,026 million.1
The Tanners' Council estimates the value of shipments in 1974
also at $1,026 million and in 1975 at $1,118 million.2
Information on the value of shipments is not available on a
state-by-state basis.
Geographical Distribution. Although there are leather
tanning and finishing establishments in 34 states, the industry
is not widely dispersed. Table 9 illustrates the number of
tanning and finishing operations in each of the states.' The
industry's geographical concentration has been determined
by factors affecting population concentrations and the locations
of the sources of raw materials, i.e., meatpacking facilities.
Major regional areas in which tanneries are concentrated:
New England (EPA Region I)—Massachusetts, Maine, and
New Hampshire
Middle Atlantic (EPA Regions II and III)—New York,
New Jersey, and Pennsylvania
North Central (EPA Region V)—Wisconsin, Illinois, and
Minnesota
Pacific (EPA Region IX)—California
2.1.3 Industry Organization and Structure. The leather
tanning and finishing industry in the United States consists
almost exclusively of family-owned businesses. Few
corporations own more than one tannery. Only one firm is
listed on a stock exchange, and only a handful of companies
are subsidiaries or operating divisions of larger corporations.
Approximately nine tanneries are subsidiaries of larger firms
not primarily associated with the leather industry. One
tanning company is a subsidiary of a meatpacking company
while three shoe manufacturers have their own tanning
facilities. 2
The industry is not characterized by an appreciable
integration, either back to raw material supply or forward
to finished or fabricated leather products. Thus, tanneries
are not owned by leather product manufacturers, and they do
not tend to own sources of their raw material. Similarly,
the ownership of the tanneries by shoe manufacturers is not
common. In recent years there has been a trend to even less
integration. One major meatpacking firm and one leading shoe
manufacturer recently divested their tanning operations. Thus,
only the previously mentioned single instance of a meatpacker-
tannery combination and three examples of direct connections
between tanneries and shoe manufacturers remain.
36
-------
Tanneries tend to be specialized in the type of raw
material processed and leather produced. The first reason
for this lack of diversification stems from the fact that
tanning equipment and processes are specialized and not
readily interchangeable in terms of raw material and end
product. For example, some equipment suitable for the tanning
and finishing of pigskins or sheepskins cannot be used for
the larger cattlehides. The second reason is the fact that
shoe manufacturing has been and still is the principal consuming
industry. In 1962, shoes accounted for 83 percent of all
leather used. This ratio declined to 74 percent in 1972.2
This caused some tanneries to seek some diversification in
their production. Tanneries specializing in leather for
the upper parts of shoes (often called side leather tanneries)
attempted to modify their production techniques in order to
enter the growing garment leather market. However, this trend
does not reflect diversification of basic product line.
Rather, it indicates an effort to adapt available plant and
equipment to moderately different end use requirements.
2.1.4 Industry Trends and Future Developments.
Character and Quantity of Raw Material Supply. In the
United States there has been a large increase in the number
of cattlehides and pigskins that have become available for
processing into leather. This has been accompanied by a sharp
decline in the availability of sheep, goat, and calfskins.2
Increased consumption of beef has lead to a rise in the
number of cattlehides available for tanning. This number
has increased from 28 million hides anually to 38 million
in the period from 1957 to 1974.2 In the United States,
until recently, very few pigskins have been removed from the
animal prior to processing for meat. There are indications
that economic considerations are leading to the removal of
more pigskins prior to butchering, and it is estimated that
in 1974 as many as 4 million pigskins were available for
tanning.2
Concurrent with the increase in cattlehide and pigskin
supply in the United States, there has been a corresponding
decrease in the availability of goat and kidskins, sheep and
lambskins, and calfskins. Skins from goats and sheep have
been traditionally imported; however, it has become the
policy of the nations supplying most of these skins to encourage
the utilization of the skins locally, thus leaving few skins
available to U.S. tanners. Production of leather from these
skins has declined drastically in this country. Goat and
kid leather production was over 22 million skins (about 3.3
million equivalent hides) in 1957 and practically zero in 1974.
Sheep and lamb leather production also has shown a drastic
reduction.2 The worldwide change in taste from veal to beef
37
-------
has caused a decline in the availability of calfskins for
tanning. Calf leather production has declined from 9 million
skins in 1957 to less than 1.5 million in 1974.2
Other types of skins or hides processed in the United
States on a very limited basis include deer, elk, moose,
antelope, rabbit, horse, and shark. Cattlehides, however,
constitute an ever increasing percentage of the raw materials
for tanning in this country. Currently, nearly 90 percent of
all leather tanned is cattlehide leather.2
Development of Substitute Materials for Leather. The
development of a synthetic substitute for one type of leather
has caused a dramatic decrease in its production. Before the
introduction of synthetics immediately after World War II,
over 80 percent of all shoes had leather soles. By 1974,
only 14 percent of the shoes produced in the United States
had leather soles, the remainder using synthetic materials.
This caused a corresponding decline in the production of
vegetable tanned leather. In 1957, over 5 million hides were
vegetable tanned for the production of shoe soles. In 1974,
only slightly over 2 million were vegetable tanned.2
Competitive Economic Status of the Industry. In spite
of the fact that the United States has a plentiful supply of
cattlehides, American tanners have not been able to take
full advantage of this raw material. The development of shoe
and other leather consuming industries in countries with low
labor costs and government subsidies to their tanning
industries has put American tanners at an economic disadvantage
and has lead to a decline in this industry in the United
States. Consequently, there has been a decline in leather
demand by consuming industries in the United States. A
corresponding increase in the demand for American hides, i.e.,
not tanned, has developed in other countries to supply their
tanning industries. In 1974, the United States exported
more than half of the 38 million cattlehides produced.2
Economic and Technical Changes. In the past few years,
there has been a tendency to complete part of the leather
tanning operations near the source of the hides, i.e., near
the meatpacking activity, to reduce transportation expenses.
This has given rise to the development of two new types of
tanneries—called, for the purpose of this study, the
beamhouse/tanhouse facility and the re tan/finisher. Essentially,
these are the operations conducted in a complete chrome tannery
with the processing of the hides through the tanning operation
carried on in the beamhouse/tanhouse facility and the processes
from retain through leather finishing conducted by the
retan/finisher. The beamhouse/tanhouse facility receives
and processes cured or fresh hides (currently the trend is
toward more fresh hides) through the beaming and tanning
38
-------
operations. Following chrome tanning, the now blue hides
are shipped to the retan/finisher where the retanning and
finishing processes are completed. Some tanneries have
split their operations into two physically separated locations,
and there are some firms which specialize in one-half or the
other of this process. In 1974, approximately 10 percent of
the hides tanned in the United States passed through this
two-step process. It is estimated that this trend will
continue. ^
Environmental Considerations. Tighter restrictions
regarding wastewater discharge from tanneries either directly
to navigable waters or into municipal sewer systems may be
influencing some relocations and changes in the industry.
The development of the beamhouse/tanhouse facility dnd
retan/finisher is partly due to these considerations. Older
complete chrome tanneries located in the New England States
often do not have the land available to construct pretreatment
facilities necessary to remove the significant waste load
generated by their beamhouse operations, thus the beamhouse
and tanhouse could be physically moved to a location nearer
to the source of hides. These locations are also more readily
able to absorb the waste effluent from these operations,
i.e. , they have adequate wastewater treatment capacity or
on-site evaporative disposal can be practiced. Research is
underway to change operations and processes in order to reduce
water consumption and wastewater generation.
Trends. The foregoing description of industry trends
gives an indication as to the future developments that can be
expected in the leather tanning and finishing industry.
It can be predicted that changes will take place gradually
in response to the following factors:
Changes in the character and quantity of raw material
supplied will lead to increased production o'f
leather made from cattlehides in the United States.
The development of newer substitute materials for
leather will require experimentation and adapation
within the tanning industry in order to obtain
leather of different properties in order to
adequately respond to the requirements of changing
markets, i.e., the tanning industry will have to
innovate in order to maintain and solidify its
share of the market for similar materials.
Economic and technical changes as well as the
reaction to environmental considerations will result
in a continued trend to relocation of facilities
close to the source of cattlehide supply. This will
lead to a gradual growth in importance of those
operations having a beamhouse/tanhouse facility
in one location and a retan/finisher in another.
39
-------
2.2 Approaches to Characterizing Tanneries
2.2.1 Census of Manufactures. The Bureau of the Census
classified the leather tanning and finishing industry
(SIC 3111) into three types of establishments1:
Regular tanneries—establishments which perform
all or a part of the usual manufacturing functions
within one organization.
Converters—handlers or managers of hides being
processed into leather. Converters may own the
material in question but do not perform manufacturing
functions which are contracted in whole or part
to contract tanneries.
Contract tanneries—processors of materials owned
by another party, e.g., a converter. Contract
tanners may provide all manufacturing processes
or only selected steps in the processing chain,
e.g., contract finishing operations. The latter
situation is the most common.
It should be noted that the SIC classifications are not
mutually exclusive. Some firms in the industry act in one,
two, or all three of the above classifications. The Bureau
of the Census classified plants according to the category in
which the highest amount of wage and salary payments are
made.
2.2.2 Production. The Tanners' Council uses a
statistical unit called an equivalent hide to convert all
types of raw material used for leather into a common unit
of measure. This device allows the classification of all
plants by size regardless of whether cattlehide, sheepskin,
pigskin, or other raw material is processed. An equivalent
hide is equal to a surface area measurement of 3.7 m2
(40 ft2) . This unit of measurement was selected because
most hides tanned in the United States are cattlehides and
the average size of a cattlehide is approximately 3.7 m2
(40 ft2). Using production measured in equivalent hides,
the Tanners' Council has divided the industry in the following
manner:
Production in Percent of
Size equivalent hides No. of plants in
category per day plants the industry
X-S (extra 200 or less 67 22
small)
S (small) 201 to 600 114 37
M (medium) 601 to 1,200 60 21
L (large) 1,201 to 2,600 32 11
X-L (extra 2,600 or more 25 9
large)
40
-------
The distribution by state and EPA region using the
above production size categories is shown in Table 9.
It can be seen from this table that most of the extra small
and small tanneries are located in the historical tanning
areas of the New England and Middle Atlantic States (EPA
Regions I and II). The large and extra large plants are
located in the Midwest (EPA Regions V and VII) and Far West
(EPA Region IX), as well as in the New England and Middle
Atlantic States (EPA Regions I and II), and are near the
source of cattlehides.
2.2.3 Tanning Process. Essentially all of the leather
in the United States is produced by tanning with trivalent
chromium (Cr+3) or with extracts from the bark of certain
trees. These processes are commonly referred to as chrome
and vegetable tanning, respectively. Approximately 87 percent
of the 20.2 million equivalent hides tanned in this country
in 1974 were processed using chrome tanning.2 Essentially
all of the remaining 2.6 million equivalent hides were
vegetable tanned. Insignificantly small numbers of equivalent
hides were tanned for special purposes using alum, zirconium,
or other tanning materials.
Table 10 indicates the distribution of tanneries by
the type of tanning process employed. The chrome tanneries
make up 93 percent of the total number of tanneries. It should
be noted that the vegetable tanneries are often located in
sparsely populated Middle Atlantic (EPA Region III) and
Southern States (EPA Region IV) and, within those states,
they are often found in rural areas near the former source
of the barks required in their processes. Currently, most
vegetable tanneries in this country use imported bark
extracts for their tanning and do not rely on local sources.2
2.2.4 Raw Material. As noted earlier, cattlehide
is the most common raw material for the tanning industry.
It is followed by sheepskin and pigskin, with only small
numbers of other skins, e.g., calf, goat, reptile, etc.,
used as raw materials. Table 11 shows the distribution
of tanneries by raw material. It can be seen that the
cattlehide tanneries are widely dispersed as would be
expected by their predominance in the industry. Pigskin
tanneries are generally located in the Midwest near the
source of the raw material. Sheepskin tanneries are primarily
located in New England (EPA Region I), and New York (EPA
Region II). Although a few domestic sheepskins are tanned,
the majority are imported, primarily from New Zealand. Thus,
the location of sheepskin tanneries near seaports is
advantageous.
41
-------
TABLE 9
DISTRIBUTION OF TANNERIES BY SIZE
Region
IX
IX
VIII
IV
IV
' 1
V
VII
IV
VI
I
V
V
VII
VII
I
II
IV
'
X
IV
VI
VIII
I
III
I
III
V
Total
States Containing
Tanneries
Alaska
California
Colorado
Delaware
Florida
Georgia
Illinois
Kentucky
Maine
Massachusetts
Michigan
New riarapshire
New York
North Carolina
Ohio
Tennessee
Utah
Virginia
Washington
west Virginia
Wisconsin
Region I
II
III
IV
V
VI
VII
VIII
IX
X
Total
1
1
14
4
3
s
1
11
2
2
3
1
*
1
79
3
4
3
i
14
25
46
3
4
4
14
9
4
1
1
2
2
2
21
298
103
71
22
19
45
5
6
5
IS
7
xs
1
3
1
2
2
24
1 '
7
19
1
3
1
2
67
25
26
1
3
2
l
3
6
S
1
~T~
J
1
1
4
"T~
1
— T~
4 '
31
~T~*
2
1
— 5—
11
1C
~T™
4
"I"
s
3
"I"
"1
1
4
14
42
27
7
5
IS
5
4
4
4
l
M
~T—
r~
^|—
T'
-I"
•T~
— T~
1"
rr~
-T-
6
~r~
— T~
2
2 '
1
IT'
60
19
' IV
S
5
14
1"
3
L
-J—
~r~
—r~
—r~
~*r
— r~
i~
— r
— j-
— y
3
—2~
~r~
— r
— 3~
32
10
1
S
4
T
T
'2"~
XL
I
I"
S~
2
' 2 '
1
1
1"
3
2"
1
"3-
25
7
2
4
2
T
3
Source: Tanners' Council of America
XS (extra small)—200 or less.
S (small) —201 to 600.
M (medium) —601 to 1,200.
L (large) —1,201 to 2,600.
XL (extra large)—2,600 or more.
42
-------
TABLE 10
DISTRIBUTION OF TANNERIES BY TANNING PROCESS
Region
X
IX
IX
VIII
III
IV
IV
V
V
VII
IV
VI
I
III
I
V
V
VII
VII
I
II
II
IV
V
X
III
IV
VI
VIII
I
III
X
III
V
Total
States Containing
Tanneries
Alaska
Arizona
California
Colorado
Delaware
Florida
Georqia
Illinois
Indiana
Iowa
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Missouri
Nebraska
New Hampshire
New Jersey
New York
North Carolina
Ohio
Oregon
Pennsylvania
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Region I
II
III
IV
V
VI
VII
VIII
IX
X
Total
1
1
14
4
3
3
1
11
2
2
3
1
9
1
79
3
4
3
1
14
25
46
4
4
14
9
4
1
2
2
21
298
103
71
22
19
45
5
6
5
15
7
Chrome
1
1
14
4
3
3
11
2
1
9
79
3
4
2
1
14
25
46
1
4
3
11
7
3
1
1
1
2
21
278
103
71
15
11
43
4
5
5
15
6
Vegetable
1
2
3
1
1
2
1
3
2
1
1
2
20
0
0
7
8
2
1
1
0
0
1
Sourcei Tanners' Council of America
43
-------
TABLE 11
DISTRIBUTION OP TANNERIES BY RAH MATERIAL
Region
X
IX
IX
VIII
III
IV
IV
V
V
VII
IV
VI
I
III
I
V
V
VII
VII
I
II
II
IV
V
X
III
IV
VI
VIII
I
III
X
III
V
Total
Region
States Containing
Tanneries
Alaska
Arizona
California
Colorado
Delaware
Florida
Georgia
Illinois
Indiana
Iowa
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Missouri
Nebraska
New Hampshire
New Jersey
New York
north Carolina
onio
Oregon
Pennsylvania
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virgin! -
Wisconsin
I
II
III
IV
V
VI
VII
VIII
IX
X
Total
1
1
14
4
3
3
1
11
7
7
J
1
14
25
46
3
4
4
14
9
4
1
1
2
2
2
21
298
103
71
22
19
45
5
6
5
15
7
Cattle
hide
1
11
1
3
1
i
8
2
1
3
5
1
42
2
2
J
1
11
IS
11
3
4
J
11
5
3
1
1
1
2
12
171
59
26
18
13
30
3
5
2
12
3
Calf
skin
1
1
1
3
1
1
1
Sheep
skin
1
2
1
1
4
20
1
1
3
22
3
1
2
62
25
25
1
Pig*
akin
1
I
1
Other
1
1
3
2
1
IB
1
2
7
13
1
4
2
e
61
19
20
4
9
1
3
1
4
Source: Tanners' Council of America
* Although only one tannery in the country uses pigakin
as its principal rav material, approximately 20 have experimented
with pigskin and are developing processes and technologies for ita
use.
** Primarily specialized contract operations such as
finishing.
A f.
-------
2.2.5 Industry Categorization. None of the previously
discussed approaches to characterization can be used to
categorize the tanning industry for the purposes of this
study. The wastestreams generated currently and in the
future are functions of several factors including type
of tanning, production operations (dictated to some degree
by raw material and type of end product), and industry
trends. After considering these factors, the following
categories were developed:
Complete chrome tannery.
Vegetable tannery.
Sheepskin tannery.
Split tannery.
Leather finisher
Beamhouse/Tanhouse facility
Retan/Finisher
During the first tannery visits and after discussions
with industry officials, it became apparent that categories
to be used in this project would not be the SIC subdivisions
used by the Bureau of the Census.1 Objections to
categorization based upon SIC were noted in Section 2.2.1.
Similarly, a strict delineation based solely upon tanning
process, raw material used, product produced, size, or
age of the tannery was not appropriate since none of these
criteria adequately separated the industry into categories
useful in determining and projecting waste characteristics
and quantities. Therefore, the qualitative and quantitative
differences among the wastestreams generated in the various
types of tanneries served as the bases for characterizing
the industry's wastes.
The first category developed was based upon the type of
tanning agent, chrome or vegetable. The chrome tanneries
and specialty operations were then further subdivided. It
was found that cattlehide and pigskin tanneries produced
similar types of solid wastes and also had similar waste
generation factors, i.e., kg of waste produced per 1000
equivalent hides. Chrome sheepskin tanneries were notably
different. Since most sheepskins are imported partially
processed, little beaming is required. Additionally, the
practice of fleshing after tanning produces a unique
wastestream—chrome fleshings. Thus, based upon raw
material and subsequent wastestream generation, two
additional categories evolved—the complete chrome tannery
(including cattlehide and pigskin) and the sheepskin
tannery.
Another type of operation yielding considerably
different waste quantities than the complete chrome tannery
is the split tannery. In these operations, the chrome tanned
45
-------
split is trimmed, often resplit, and trimmed again before
going through the retan, color, and fatliquor cycle. The
sequence of trimming, splitting, and trimming yields higher
waste generation factors for trimmings and shavings than is
found in the complete chrome tannery. Another difference
between the complete chrome operation and the split tannery
is that the split tannery does essentially no finishing.
Thus, there is no finishing residue requiring land disposal.
Therefore, the split tannery was considered a separate
category.
Contract leather finishers make up the largest segment
of the contract operations conducted in the tanning
industry. Their operations are similar to the finishing
procedures used in complete chrome tanneries; however, some
unique operations are included for specialty leathers. Since
the finishers have no actual tanning operations, they were
designated a separate category.
Vegetable tanneries are notably different in their
processing steps and resultant solid wastestreams. The
absence of chromium and other heavy metals lead to the
presumption, later supported by analytical evidence, that
vegetable tanneries produced no potentially hazardous wastes
destined for land disposal.
Industry trends were also considered in the development
of the categories for this project. The trend most influencing
the types and quantities of solid waste produced in tanneries
is the development of the beamhouse/tanhouse facility and
retan/finisher. As noted earlier, these operations evolve
from the separation of the classical complete chrome tannery
into two segments. In the beamhouse/tanhouse facility, the
hide is received and processed through the tanning operation.
It is then transferred to the retan/finisher where processing
continues, beginning with the retan, color, and fatliquor
cycle, and ending with the finishing, measuring, and packaging
of the leather. Only a small number of beamhouse/tanhouse
operations currently produce "blue stock," or chrome tanned
leather which has not yet been retanned and finished.
However, a number of tanneries are investigating the
possibility of establishing their own remote beaming and
tanning operations. Several complete chrome tanneries have
experimented, with varying degrees of success and acceptability,
with using blue stock purchased from a beamhouse/tanhouse
facility. The trend for the establishment of these two types
of operations was taken into account for purposes of projecting
waste quantities in 1977 and 1983.
These seven categories were developed to provide as
accurately as possible a picture of the solid waste generated
in the leather tanning and finishing industry. They include
46
-------
as much of the industry as possible and yet minimize the
number of categories. In addition, the categories were
designed to account for production trends in order to
project the quantities of waste generated in 1977 and 1983.
Table 12 lists the number of establishments in each
category by state and EPA Region. As shown, all types of
tanneries, except beamhouse/tanhouse facilities and vegetable
tanneries, are located primarily in EPA Regions I, II, and V.
Vegetable tanneries are located primarily in EPA Regions III
and IV, and beamhouse/tanhouse facilities are distributed
quite evenly among EPA Regions V through IX.
47
-------
TABLE 12
DISTRIBUTION OP TANNERIES DY CATEGORY
Region
X
IX
IX
VIII
III
IV
IV
V
V
VII
IV
VI
I
III
I
V
V
VII
VII
I
II
II
IV
V
X
III
IV
VI
VIII
I
III
X
III
V
Total
Region
States Containing
Tanneries
Alaska
Arizona
Ca .ifornia
Colorado
Delaware
Florida
Georgia
Illinois
Indiana
Iowa
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Missouri
Nebraska
New Hampshire
New Jersey
New York
North Carolina
Ohio
Oregon
Pennsylvania
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
I
II
III
IV
V
VI
VII
VIII
IX
X
Total
1
1
14
4
3
3
1
11
2
2
3
1
9
1
79
3
4
3
1
14
25
46
3
4
4
14
9
4
1
1
2
2
2
21
298
103
71
22
19
45
5
6
5
15
7
Complete
Chrome
1
9
3
1
1
8
1
3
15
3
2
1
1
9
4
15
1
3
5
5
1
1
2
12
107
27
19
7
6
26
1
2
4
9
6
Vege-
table
1
1
2
3
1
1
2
1
3
2
1
1
2
21
7
8
3
1
1
1
Split
1
1
14
l
2
5
24
15
2
6
1
Beamhouso/
Tanhouso
1
1
1
1
1
1
1
7
1
10
1
2
Z
2
1
2
Rctan/
Finish
2
1
7
1
3
6
3
1
1
25
9
9
3
1
1
2
leather
Finish
1
2
1
1
29
1
1
16
10
1
3
1
1
68
31
26
2
2
6
1
Sheop
skin
2
1
4
14
;
~J
13
3
1
1
i
43
21
14
3
Z
1
1
1
Source: Tanners' Council of America
48
-------
SECTION 3.0
WASTE CHARACTERIZATION
3.1 Development of Typical Plants
In this section, production processes and the types
and quantities of process solid waste resulting from each
process are described for each category of the industry. A
definition of potentially hazardous waste is presented, and
the types and quantities of process solid waste currently
generated which are potentially hazardous and are destined
for land disposal are identified. Projections are made for
the quantities of solid waste anticipated to be produced
in 1977 and 1983. Waste quantity projections are based upon
estimates of changes in industry production, the effects
of air and water pollution control regulations, and various
in-plant process changes. In addition to waste quantities,
the quantities of hazardous constituents within the potentially
hazardous wastestreams are presented for 1974, 1977, and
1983.
In order to present the available information in a
concise and understandable manner, "typical" plants have
been identified for the major categories of tanneries. Mass
balance diagrams for these typical plants reflect general
operations as well as input and output of materials per
unit of production. It must be emphasized that tanneries,
even within the categories described in this section, vary
widely in size and operation, e.g., 100-fold differences.
All typical plants are located in urban areas, predominantly
in the East or Midwest (EPA Regions I, II, III, IV) and
utilize contract services for solid waste hauling and
disposal. All of the typical plants are 50 years old with
the exception of the beamhouse/tanhouse facility which is
15 years old.
3.1.1 Approach to Waste Characterization. Process
solid waste is defined, for this study, as solids, sludges,
and other waste generated directly as a result of the
manufacturing processes in the industry and normally disposed
to the land. These wastes primarily consist of small pieces
of leather in various stages of processing or sludges
collected from sewer sumps or wastewater treatment facilities.
Other items in the process wastestream include:
. Salt and string from the hide receiving areas.
Empty bags and drums from chemical mixing areas.
. Finishing residues (scrapings and sludges) from
finishing department.
General plant floor sweepings.
49
-------
Not included as process solid waste was:
Office and lunchroom waste.
Paper towels, etc. from restrooms.
In order to determine the types, quantities, and
characteristics of the process solid waste generated by the
tanning industry, 41 tanneries were visited. During the
tannery visits, the following types of information were
obtained:
Production.
Types and quantities of chemicals used.
Types and quantites of solid waste generated.
Analytical wastewater information, particularly
quantities discharged and solids content.
Information concerning air pollution control
devices and solids generated.
By-product sales data.
A total of 156 waste samples were collected from 28
of the 41 tanneries visited. These samples were
subsequently analyzed for a variety of hazardous organic
and inorganic constituents. An outline of the procedures
for collection, shipment, and analysis of the samples
is included in Appendix B.
Utilizing the data collected at the tanneries and the
laboratory analytical results, a matrix was developed for
each major type of wastestream found in tanneries. Figure
4 is an excerpt from one of the matrices. Examination
of the matrices showed clearly where variations in the
composition of a particular waste occurred as a result of the
type of tannery in which it was generated. Based upon this
and a consideration of production trends in the industry,
the seven categories of tanneries were identified. As an
example of the use of the matrix, the toxic, heavy metal
content in wastes from vegetable tanneries was at a level
below the selected threshold. This was the only group of
tanneries for which this was true and thus led to the
establishment of vegetable tanneries as a separate category.
In order to summarize the operations performed at each
of these seven categories of tanneries, mass balance
diagrams were developed and are included in Sections 3.3
through 3.9. Each diagram is divided into three sections
vertically. General processing steps are shown down the
center. The materials added are shown on the left and the
finished leather, by-products, and waste are shown at the
bottom and right. The figures shown are the kg of each
constituent (on a dry weight basis) per 1000 equivalent
hides.
50
-------
FIGURE 4
EXAMPLE OF WASTESTREAM MATRIX
Plant and Sample No.
Process
Production (hides/day)
Waste Quantity
(Ib/day) g|
-------
Utilizing the above data, information regarding
industry production and trends provided by the Tanners'
Council, and a criteria developed for defining potentially
hazardous waste (discussed in Section 3.2), the quantities
of total process solid waste and potentially hazardous
solid waste were estimated for 1974, 1977, and 1983. Waste
generation factors were developed for each wastestream and
hazardous constituent for each category of tannery. These
factors are in kg per 1000 equivalent hides and take into
account process changes which will vary the generation rates.
Production for each category of tannery in each state during
1974 was provided by the Tanners' Council and was projected
for 1977 and 1983.
Each of the seven tannery categories is discussed in
turn, in Section 3.3 through 3.9: The major points
included in each section are:
Plant operations (including the mass balance diagram).
Discussion of sources and quantities of potentially
hazardous and non-hazardous waste.
Factors affecting future solid waste generation.
Summary tables of waste quantities (both total
process and potentially hazardous solid waste).
3.2 Determination of Potentially Hazardous Waste
3.2.1 Criteria. "Potentially hazardous waste" is
defined as waste or combinations of waste which pose a
substantial present or potential hazard to human health or
living organisms because such waste is lethal, non-degradable,
or persistent in nature; may be biologically magnified; or
otherwise cause or tend to cause detrimental cumulative
effects.3 Waste is classified as potentially hazardous due
to the presence of hazardous constituents at a concentration
level above a selected threshold. Thus, the constituents
of the waste, e.g., specific, toxic, heavy metals, are
referred to as hazardous. These hazardous constituents make
a waste potentially hazardous if they occur in sufficient
concentration.
Potentially hazardous waste contain constituents which
are:
Radioactive.
Infectious.
Explosive.
Flammable.
Irritants or strong sensitizers.
Corrosive.
Toxic.
52
-------
Of the above listed characteristics which may make a
wastestreara potentially hazardous, toxicity is the most
significant to this study, and at the same time the most
difficult to define. The toxicity of a substance is largely
dependent upon the concentration levels under various
environmental conditions. An assessment of the degree of
hazard introduced by the disposal of waste containing naturally
occurring constituents is not a simple straight line or
exponentially increasing function starting from zero, as it
may be for many synthesized compounds. This results from the
fact that life forms have evolved in the presence of, and
acclimated to, these naturally occurring elements and their
compounds at the naturally occurring background concentration
levels in various environmental media. As a result, many
of the substances of particular concern in this study,
primarily heavy metals, are prerequisites to life in trace
quantities, but are toxic at higher concentrations.
The uncertainty and confusion about what concentration
levels are hazardous arises because:
In the complete absence of certain elements, life
cannot exist.
. There is a vaguely defined intermediate concentration
range in which these substances are essential and/or
can be tolerated.
There is a higher level above which chronic and acute
toxicity may result.
A clear definition of the threshold toxicity level of
a particular element or compound is further complicated by
the fact that these threshold concentration levels are:
Highly variable from one species to another.
Extremely dependent upon the medium or environment
in which they live, and on the medium of exposure
(water, soil, or air).
Altered by synergistic or antagonistic reactions
in a particular environment.
. Affected by such factors as temperature, pH, and
the presence of other ionic species.
Furthermore, the form in which an element occurs, e.g.,
as a mineral, as a pure element, or as a water soluble salt
or oxide, strongly influences its toxicity to various organisms.
Previous studies and lists of hazardous materials promulgated
by Federal agencies served as the basis for determining whether
a given wastestreara constituent should be considered
hazardous.
53
-------
3.2.2 Definition of Potentially Hazardous Waste.
Definitive information concerning the environmental fate
and subsequent effects of the hazardous constituents in the
solid waste generated by the leather tanning and finishing
industry is not available. Scientific studies of the
environmental fate of tannery solid waste following land
disposal have not been conducted, and in many instances the
chemical structure of tannery solid waste is not well
understood. As a result, it was necessary to select a
recognized, reasonable reference for identifying the
concentration level at which a hazardous constituent should
be present in order to consider a waste as potentially
hazardous. As a guide as to what constitutes potentially
hazardous concentration levels in waste destined for land
disposal, the geometric means of the background concentration
levels of these constituents in soils in the United States
were used as this reference.4 Table 13 lists these values for
heavy metals.
The geometric mean concentration in U.S. soils was
selected because the study was confined to and focused on
land disposal of tannery waste in this country. As noted
earlier, little is known of the environmental fate of tannery
waste following land disposal. The geometric mean soil
concentration gives the best indication of the concentration
of hazardous constituents in the soil environment which
plant and animal life can surely tolerate. However, increases
in the concentration of hazardous constituents above these
levels may result in an adverse impact on the environment.
Consequently, tannery waste with hazardous constituent
concentrations above the corresponding mean soil concentration
should be considered potentially hazardous until such time
as studies are conducted which indiate a different value
is environmentally sound.
During this study, waste samples were collected and
analyzed to determine the concentrations of potentially
hazardous constituents in all types of tannery solid waste.
The results of these analyses showed that copper, zinc, lead,
and trivalent chromium were present in various types of solid
waste at concentrations exceeding the geometric mean background
levels present in U.S. soils. The information available
in the relevant literature and previously contracted studies
indicates that copper, lead, zinc, and trivalent chromium
are moderately to highly toxic materials.7'11'12
Samples were analyzed for other heavy metals (mercury,
arsenic, zirconium, beryllium, cadmium, and selenium) and
other hazardous constituents (pesticides and phenols), but
none were found in significant quantities.
Eight types of solid waste from tanneries producing
chrome tanned leather were identified as being potentially
hazardous due to their heavy metal content. Additionally,
54
-------
TABLE 13
GEOMETRIC MEAN COMPOSITIONS, AND GEOMETRIC DEVIATIONS, OF SAMPLES OP SOILS
AMD OTHER SURFTCIAL MATERIALS IN THE CONTERMINOUS UNITED STATES
(GEOMETRIC MEANS REPORTED IN PARTS PER MILLION)
ui
01
The conterminous
United States
n* = 863
Element
Al
B
Ba
Be
Ca
Co
Cr
Cu
Fe
Ga
K
Kg
Mn
Ha
Hi
P
Pb
Ti
V
In
It
Geometric
mean
45,000
26
430
0.6
8,800
7
37
18
18,000
14
12,000
4,700
340
4,000
14
250
16
2,500
56
44
200
Geometric
deviation
2.41
2.05
2.06
2.49
3.92
2.21
2.32
2.28
2.30
2.11
2.71
3.19
2.70
4.11
2.26
2.74
1.96
1.87
2.16
1.86
1.90
Western United States
(west of 97th merMian)
n* ss 492
Geometric
mean
54,000
22
560
0.6
18,000
8
38
21
20,000
18
17,000
7,800
389
10,200
16
320
18
2,100
66
51
170
Geometric
deviation
2.02
2.09
1.80
2.47
2.93
2.01
2.16
2.00
1.90
l.?l
1.60
2.21
1.94
1.98
2.03
2.33
1.93
1.82
1.91
1.78
1.78
Eastern United States
(east of 97th meridian)
ri* ?=• 371
Geometric
mean
33,000
32
300
0.6
3,200
7
36
14
15,000
10
7,400
2,300
285
2,600
13
180
14
3,000
46
36
250
Geometric
deviation
2.70
1.92
2.19
2.53
2.87
2.55
2.52
2.54
2.76
2.53
3.56
3.39
3.65
4.11
2.60
3.03
1.96
1.84
2.41
1.89
1.95
Sources Reference 21
• n » Number of samples,
-------
the finishing residue wastestream (already categorized as
potentially hazardous because of its metal content) also
contains flammable solvents and is thus considered potentially
hazardous on two counts. The wastestreams categorized as
potentially hazardous are shown in Table 14. Also listed are
the concentrations (mean .and range) on a wet weight basis.
This is compared to the geometric mean concentration in U.S.
soils. The mean concentration of trivalent chromium in
all waste was well above the soil concentration, ranging from
59 to 457 times the mean concentration in U.S. soils.
3.2.3 Discussions of Hazardous Constituents-. Information
on the toxicity of copper, lead, zinc, and trivalent chromium
is summarized in Table 15. As the table indicates, all of
these metals have been shown to be moderately toxic (LDso
from 500 to 5,000 mg/kg) or very toxic (LD5p from 50 to 500
mg/kg), as a result of tests on experimental animals.
Although the environmental effects of lead, zinc, and
copper are not completely understood, the phototoxicity of
zinc and copper to agricultural crops, the toxicity of lead
to man, and the toxicity of all three elements to various
aquatic organisms, is well established. The toxicological
information on chromium, however, is conflicting. Of these
four elements, only lead is thought .to have detrimental
effects on human health in low to moderate concentrations, and
correspondingly only lead has a mandatory drinking water
standard. Zinc and copper have recommended limits. Hexavalent
chromium has a mandatory limit, but there is no stated limit
for trivalent chromium.13
Chromium. Chromium and its compounds take on unusual
importance in this study because of-their prevalent use in
the tanning process. Chromium occurs often, and in high
concentrations, in both wastewater and solid wastestreams.
The chrome tanning process employs basic trivalent chromium,
chromic sulfate (empirical formual Cr(OH)SO4). However, some
tanneries purchase sodium dichromate (hexavalent chromium)
as a raw material and reduce it to trivalent chromium
preparatory to usage. In its hexavalent state (as chromic
oxide, chromate, or dichromate), chromium is a strong
oxidizing agent which reacts readily with organic matter in
acidic solution. Complexes in which hexavalent chromium
would be stabilized against reduction by organic matter are
now known. All biologic interactions with chromate should
result in reduction to the trivalent form and later coordination
to organic molecules. This has been widely demonstrated by
the effect of chromate on skin, the interaction of dichromate
or chromates with nucleic acids and with the reaction and
fate of chromate injected into experimental animals.9
56
-------
TABLE 14
POTENTIALLY HAZARDOUS TANNERY HASTES
Anal'
Results
Waste Stream
Be. of
Samples
Hazardous
Constituent*
Concentration
(wet weight-
mg/kg)
concentration
Range**
(wet weight-
Geometric Mean
Concentration in
O.S. Soils (dry
weight-mg/kg)
Chrome (blue) 10
trimmings i
shavings
Chrome fleshings 1
Unfinished chrome 9
leather trim
Buffing dust 12
Finishing residues 1C
Finished leather
trim
Cr+3
+3
Cr
Cu
Pb
•n
Cu
Pb
In
Cr**
Cu
Pb
Sa
7,600
4,000
16.900
90
iao
60
5,700
960
ISO
160
3.500
40
8.400
ISO"
14.800
1,000
2,200-21,000
4.600-37,000
2.3-468
2.5-476
9.1-156
19-22,000
29-1,900
2-924
0.45-12.000
0.35-208
2.5-69.200
X4-87C
1.600-41.000
100-3.300
37
37
37
18
16
44
37
18
16
44
37
18
16
37
16
Sewer screenings
17
Pb
In
2.200
30
60
0.27-14.000
2-110
35-128
37
16
Mastewater treatment 27
residues (sludges)
Cr
Cu
Pb
Sn
,+S
3,700
370
60
50
0.33-19.400
0.12-8,400
0.75-240
1.2-147
37
18
16
44
Sourcet Laboratory analytical results and Reference 21
t Since tannery wastes ere land disposed in a wot condition, i.e.,
containing moisture, reporting constituent concentrations oa a
wet weight basis realistically portrays the waste streams*
chemical characteristics with respect to hazardous constituents.
Constituent concentrations in O.S. soils were not available on a
wet weight basis. Geometric mean values one wet weight basis would
be slightly less than those reported above. Thus the method of
reporting the concentration* (wet or dry basis) does not impact
on the designation of a waste stream as non-hasardous or potentially
hasardoua.
• For which analyses were made.
•• Range not shown when only one sample was anelysed for the constituent.
57
-------
TABLE 15
SUMMARY OF TOXICITY-RELATED INFORMATION FOR CHROMIUM (III) ,
LEAD, ZINC, AND COPPER
ui
00
LD50
TL
n
USPRS
Drinking
Water
Standard
Chromium (III)
Cr,(S04)3:
500 to 57000
mgAg
1.2 - 40 mg/1.
various species
under various
conditions.
None for Cr
(III); 0.05
mg/1 for Cr(VX)-
mandatory
Lead
Salts: 50 - 500
mg/kg
0.1 - 6.3 mg/1.
various species
of fish, 24 -
96 hours.
0.05 mg/1 -
mandatory
Zinc
Salts: 50 - 500
mgAg
0.1 - 13 mg/1.
Various species
of fish 24 -
96 hours.
5.0 mg/1
(recommended)
Copper
Salts: 50 - 500
mgAg
0.02 - 3.0 mg/1.
Various fish
under various
conditions.
1.0 mg/1
(recommended)
Sources References 15. 19
-------
This organic reduction of any residual hexavalent
chromium to the trivalent form during the tanning process
has been confirmed by analytical testing of a cross-section
of chromium containing wastestreams selected at random as
a part of this study. Eighteen such determinations were made
on the following samples:
Waste type No. of samples
Trimmings and shavings 3
Buffing dust 2
Finishing residues 3
Screenings 2
Wastewater treatment sludge 8
Hexavalent chromium concentrations in all 18 samples
analyzed were below the detection limit (0.05 mg/1).
Based on this, there is strong reason to believe that even
accidental spills of hexavalent chromium would be reduced
before leaving a tannery if conveyed through a portion of
the sewer system and/or treatment process. One instance
of hexavalent chromium appearing in tannery waste has been
reported.14 However, this isolated report has not been
confirmed. Thus, the only chromium compound of concern and
interest in this study is trivalent chromium.
Trivalent chromium is far less toxic than hexavalent
chromium based upon available information in the literature.5'6''
Since a large percentage of the chromium containing solid
wastestreams are now being land disposed, the concentration
ranges at which chromium impacts on plant and animal forms
is of crucial importance to this study. Some information
is available on the effects of chromium on plants which
generally indicates that low concentrations of chromium
appear to be beneficial, or possibly even essential, whereas
higher concentrations may be toxic. The effects vary with
species and with specific chromium compound. The effects
on plant growth of adding chromium to the soil depend upon
the amount of chromium naturally present in the soil. In
some instances, crop yields have been improved by application
of chromium to soils. The following examples have been
excerpted from the literature:
. The addition of chromic sulfate (Cr2(804)3) to 8oil
at 600,000 mg/ha (0.54 Ib/acre) improved the weight,
size, and sugar content of grapes by 21, 18, and 23
percent, respectively, while increasing the yield
by 205 to 245 kg/ha (183 to 219 Ib/acre),15
The application of a fertilizer containing 4,300
mg/kg chromium resulted in increased growth in
flax grown on sand.16
59
-------
Addition of chromous acetate in concentrations of
500 mg/1 or less had a beneficial effect on carrots,
barley, lupines, and cucumbers.17
Application of chromium (as the alum) at 40,000
mg/ha (0.036 Ib/acre) to a soil containing
extractable chromium at only 65 mg/kg increased
the yield of potatoes from 32.7 to 46.5 tons
per hectare (13.2 to 18.8 tons/acre).18 Similar
results were obtained for peas, carrots, and beets.19'20
. Applications of potassium dichrornate at 30,000 and
100,000 mg/m3 (0.03-lb/yd3) of soil increased the
yield of cucumbers.
. Chromium at 1 mg/1 in nutrient solution benefited
lettuce slightly.21
Chromium at 5 mg/kg increased the rate of
nitrification. Z1
Conversely, a number of observations have been made of toxic
effects of trivalent chromium as follows9:
Tolerated Toxic
concentration concentration
Plant (ppm) (ppm) Chemical form
Orange
seedlings 75 150 Chromium
Corn
seedlings .5 5 Chromic sulfate
Tomatoes, 16 — Chromium as
Oats, Kale, (yield Chromate
Potatoes reduced)
Oat 5-10 (produced 15-50 Chromium
Plants iron chlorosis) (chromic or
chromate)
Tobacco — 5 Chromate
Corn — 10 Chromate
in addition, toxicity has sometimes been associated
with trivalent chromium in plant tissues. In fruits,
vegetables, and grains concentrations from trace amounts
to 14 mg/kg (dry tissue) were generally tolerated; but
toxic effects appeared in corn with leaves containing
4 to 8 mg/kg and in oats with leaves containing 252 mg/kg.
Tobacco grown in serpentine soil with an atypically high
concentration of trivalent chromium showed toxic symptoms
when the leaves contained 18 to 34 (dry weight) mg/kg,
although no toxic effects were visible at 14 mg/kg. The
roots showed signs of toxic effects at 375 to 400 mg/kg.21
60
-------
Toxicity of trivalent chromium to various aquatic
organisms has also been reported in the literature and is
summarized in Table 16. 6'9 Conversely, recent attempts
to repeat some of the earlier studies regarding the toxicity
of trivalent chromium to sticklebacks and other fish have
ended with the conclusion that pH and/or the solubilizing
agents used were the cause of the reported toxicity.8
Since the predominant method of disposal of chromium
containing tannery waste is land disposal, concern for the
environmental impact of disposal centers on the propensity
of a chromium containing waste to leach, its relative
mobility, soil attenuation properties, and possible
contamination of groundwater supplies.
Because the escape of chromium containing leachate
into the groundwater or to a receiving water body is the
major concern, the Tanners' Council of America conducted
(as part of this study) leaching tests of various chromium
containing solid waste. These tests, using distilled water,
indicate that from 200 to 400 mg of trivalent chromium is
released from 1 kg of trimmings and shavings in periods
ranging from 24 to 72 hours.2
Other research has shown that chromium is relatively
unaffected by most organic acids but is solubilized slowly
by acetic acid. y Acetic acid is a major component of most
anaerobic fermentation or digestion processes within
landfills, comprising an estimated 30 to 60 percent of the
total organic acids produced. These two studies suggest
that trivalent chromium could ultimately be leached out of
the waste material.
As the preceding paragraphs have indicated, the existing
information on the toxicity of trivalent chromium to plants
and aquatic organisms is contradictory in many instances.
However, trivalent chromium could ultimately be leached
from tannery waste, and since it is reported by some
researchers as being toxic to various plants and aquatic
organisms, trivalent chromium is considered to be a hazardous
constituent of tannery solid waste.
3.3 Complete Chrome Tannery
3.3.1 Plant Operations. The basic processes used to
produce chrome tanned and finished leather are shown in
Figure 5. Brine cured, prefleshed cattlehides represent
approximately 70 percent of the raw material of the tanning
industry. The other 30 percent of the raw material utilized
is fresh and salt cured cattlehides or pigskins. As
received, hides contain about 50 percent moisture. After
receipt at the tannery, the hides are normally sided (cut
in half down the backbone) to facilitate processing, and
then soaked in water to return the natural moisture to the
61
-------
TABLE 16
TRIVALENT CHROMIUM TOXICITY TO
AQUATIC ORGANISMS
Concentration
of trivalent
chromium, mg/1
1.2
1.3
2.0
2.4
5.0
5.2
-
40
4C1.2
5
37
42
75
27
0.33
Compound
Used
Cr2(S04)3
Cr2(S04)3
Cr2(S04)3
Cr2(S04)3
Cr2(S04)3
KCr(S04)2
^1 w
Cr2(S04)3
• *9 ij
CrCl3
Cr (III)
Cr (III)
Cr (III)
Cr (III)
Cr (III)
Cr (III)
Organism
Sticklebacks
Sticklebacks
Sticklebacks
Sticklebacks
Sticklebacks
Young eels
Minnows
Daphnia magna
Scenedesmus
Microegma
Daphnia
Polycelisnigra
(flatworm)
Flathead
minnows
Daphnia
Remarks
Lethal limit.
Survived only 1 wk
Survived only 2 days
Lethal limit
Survived only 1 day
Survived an average
of 18.7 hours
Survived in dis-
tilled water only
6 hours
25° C Lake Erie
water
Toxic threshold
Toxic threshold
Toxic threshold
Toxic threshold in
48 hours of
exposure
96 hour XiC^g
Chronic. No effect
level for
reproduction
Source: References 6,9
62
-------
FIGURE 5
PROCESS FLOW DIAGRAM
TYPICAL COMPLETE CHROME TANNERY
(all units are kg/1000 equivalent hides on a dry weight basis
except solid wastes which are given on a wet/dry basis)
MATERIALS ADDED
CURED CATTLE HIDES
(12.300)
BACTERICIDES (2)1 4 .
LIME (900) V_ SIDE I
NA2S/NAHS (230) f~~ • ft SOAK [~
SODA ASH (450) | FLESH
£ |
CRQHSO DRY
WATER L SOLVFMT 1 TBlu
BASE FINISHES ( 1 000 If—* CONDI T ION
MISC. (100) J BUFF
y FINISH
TRIM
FINISHED LEATH
(5000)
xn FLESHINGS (800) J ',
SOLID
(550/
PROCESS
WASTES A M
450)
1
xrvTRIM (325/140) ^ ^
X|N SHAVINGS (430/400) A I
A SPL I TS
(7600/3400) J
1
J BY-PRODUCTS
JL^J* VOLATILES TO
f^^^*"^^ ATMOSPHERE (450)
ALEATHER
ABUFFING
TRIM ( 1 14/10O) g
DUST (27/25) 11
xKFINISHING RESIDUES (ISO/45) II
XINFINISHED LEATHCR TRIM Ij
* (220/200) "•
ER WASTEWATER f
r~ i
SCREENING
A
SEWER
SUMP
WASTEWATER
TO SEWER
(SOLIDS - 92
SCREENINGS (390/9O) J
' M
1
SLUDGE (2700/300) **
\
\
\
00) |
4
PROCESS SOLID WASTES
TO SANITARY LANDFILL
(5.410/1.750)
63
-------
hide fibers. Excess flesh and fatty substances which
adhere to the hides are removed mechanically, and the hides
are treated with lime and sodium sulfide to dissolve the
hair. The hides are then treated with an enzyme in order
to loosen the fiber structure ("bated"), pickled to prepare
the hide fibers for penetration of the tanning substance,
and then tanned with a solution of basic chromium sulfate
Cr(OH)SO,.
Following tanning, excess moisture is removed by
wringing, and the hides are then split to obtain a uniform
thickness, and shaved to obtain the exact thickness
desired. The resulting blue trimmings and shavings contain
about 60 percent moisture. Next, the hides are retanned
with vegetable extracts or synthetic tanning agents (syntans)
colored with a water soluble dye or pigment, and fatliquored
(a process in which oils are added to the hides to impart
the desired degree of flexibility). The hides are stretched
on a metal frame, pasted on large plates, or hung on racks,
and then dried in an oven or heated room. The resulting
leather is trimmed to remove ragged edges, physically
conditioned to soften the leather, and buffed to smooth
the grain surface or the flesh side of the hides. At this
point, the leather containing about 10 percent moisture may
be sold, but is normally finished with a water or solvent-
base preparation to improve wear, improve its water repellent
characteristics, and/or alter its color. The finished
leather (also with a 10 percent moisture content) is then
trimmed and measured, and is ready for sale. A typical
tannery in this category processed 260,000 equivalent hides
in 1974.2
Figure 5 also indicates the basic production operations
performed, the types and quantities of raw materials and
products involved, and the types and quantities of waste
products resulting from the production process.
3.3.2 Potentially Hazardous Solid Waste. Several kinds
of solid waste is generated.The potentially hazardous
wastestreams are discussed below.
Blue Trimmings and Shavings. Blue trimmings and shavings
are generated when tanned hides are split and shaved to
obtain a uniform thickness. Average generation rates are
325 (wet)/140 (dry) kg per 1000 equivalent hides for trimmings
and 930 (wet)/400 (dry) kg per 1000 equivalent hides for
shavings, which on a national basis, totals 19,500 (wet)/
8,850 (dry) metric tons per year. The latter figures were
calculated using production data supplied by the Tanners'
Council of America. Samples were collected from the shaving
machine and from fiber drums in the trimming department of
six complete chrome tanneries. Analysis of these samples
64
-------
indicated that this type of solid waste has an average
chromium concentration of 9,600 (wet)/22,300 (dry) mg/kg,
with a range of 10,000 to 28,000 mg/kg on a dry weight
basis.
Other naturally occurring hazardous constituents are
present only at concentrations below their respective average
background concentrations in soils, if at all. Synthetic
substances were not detected in this wastestream.
Unfinished Leather Trim. Following drying and before
finishing, the sides of leather are normally trimmed to
remove ragged edges which would interfere with the finishing
process. The average rate of generation of this waste
material is 114 (wet/100 (dry) kg per 1000 equivalent
hides, which on a national basis amounts to 1,900 (wet)/
1,650 (dry) metric tons per year. Analysis of samples
collected from the trimming departments of seven tanneries
indicated the presence of the following hazardous
constituents:
Avg. concentration Concentration rang?;
{mg/kg) (mg/kg)
Constituent Wet Dry Dry
Chromium 15,000 17,000 3,600 - 42,000
Lead 110 130 3 - 530
Buffing Dust. Buffing dust is produced when the dried
and trimmed leather is mechanically sanded to remove surface
imperfections or improve the nap of the flesh side. A
representative tannery in this category generates 27 (wet)/
25 (dry) kg per 1000 equivalent hides, and all complete chrome
tanneries generate a total of 443 (wet)/400 (dry) metric
tons per year. Analysis of samples taken from the dry
buffing dust collectors (cyclone collectors and bag houses)
at seven plants showed the presence of the following
hazardous constituents:
Avg. concentration Concentration range
(mg/kg) (mg/kg)
Constituent Wet Dry Dry
Chromium 20,000 22,000 1,200 - 60,000
Lead 71 77 44 - 120
Finishing Residues. Finishing residues are produced as
a result of water-wash air pollution control devices on spray
booths and from general cleaning of the finishing equipment.
A representative complete chrome tannery generates 150 (wet)/
45 (dry) kg per 1000 equivalent hides processed, which
65
-------
amounts to 2,460 (wet)/738 (dry) metric tons per year on
a national basis. Analysis of samples taken from the finishing
area in nine tanneries indicated the presence of the following
hazardous constituents:
Avg. concentration Concentration range
(mg//kg) (mg/kg)
Constituent Wet Dry
Chromium 525 1,700 <4 - 5,200
Lead 1,100 3,600 <10 - 17,000
Zinc 105 340 Not de- 1,400
tected
In addition, flammable organic solvents comprise
approximately 10 percent of the wet weight of this waste.
This amounts to 15 kg (wet) per 1000 equivalent hides
processed or 246 (wet) metric tons per year nationally.
These solvents also make this waste potentially hazardous.
Finished Leather Trim. The final operation performed
before packaging the finished leather for shipment is
trimming. A representative plant produces 220 (wet)/200 (dry)
kg per 1000 equivalent hides processed, which on a national
basis amounts to 3,610 (wet) /3, 280 (dry) metric tons per
year. Analyses of samples taken from the trimming and
shipping department of three plants indicated the presence
of the following hazardous constituents:
Avg. concentration Concentration range
(mg/kg) (mg/kg)
Constituent Wet _ Dry __ Dry _
Chromium 19,100 21,200 7,600 - 45,000
Lead 250 280 120 - 460
Wastewater Screenings. A representative complete
chrome tannery screens its wastewater prior to discharge
for further treatment. This process generates 390 (wet)/
90 (dry) kg of solid waste per 1000 equivalent hides processed,
which on a national basis amounts to 6,400 (wet) /I, 480 (dry)
metric tons per year. Samples were collected from the
wastewater screens at seven complete chrome tanneries. An
analysis of these samples indicates that the following
constituents are present in potentially hazardous concentrations:
66
-------
Avg. concentration Concentration range
(rag/kg) (mg/kg)
Constituent Wet Dry Dry
Chromium 965 4,200 5 - 14,000
Lead 40 176 43 - 190
Wastewater Treatment Sludges (from sewer sumps). A
representative complete chrome tannery utilizes sewer sumps
to remove solids from their wastewater prior to discharge,
and generates 2,700 (wet)/300 (dry) kg of wastewater solids.
per 1000 equivalent hides processed, which amount to
34,100 (wet)/3,800 (dry) metric tons per year from all
complete chrome tanneries in the Nation. Analyses of
samples taken from sewer sumps at seven plants indicated
that the following constituents are present in potentially
hazardous concentrations:
Avg. concentration Concentration range
(mg/kg) (mg/kg)
Constituent Wet Dry Dry
Chromium 2,700 24,000 280 - 75,000
Copper 190 1,700 20 - 13,300
Lead 25 230 40 - 380
Waste Treatment Sludges (from primary and/or secondary
treatment). A few aytpical complete chrome tanneries
utilize primary pretreatment (with a rectangular or circular
clarifier) prior to discharge to a municipal sewer. In a
very few instances, primary treatment is followed by secondary
treatment (activated sludge) prior to direct discharge.
Complete chrome tanneries with primary and/or secondary
wastewater treatment and kludge dewatering remove an average
of 10,000 (wet)/2,400 (dry) kg of wastewater sludge per 1000
equivalent hides processed, which on a national basis amounts
to 34,000 (wet)/8,100 (dry) metric tons per year. The
limited number of plants employing primary and/or secondary
wastewater treatment, and variations (unquantified) among
plants in the quantities of chemicals used, prevented the
development of separate generation factors for plants
utilizing primary treatment and those with both primary and
secondary treatment. Analysis of samples of primary and/or
secondary wastewater treatment sludge collected from the
treatment systems at seven plants indicated that the following
constituents are present in potentially hazardous concentrations:
67
-------
Avg. concentration Concentration range
(rag/kg) (mg/kg)
Constituent Wet Pry Pry
Chromium 7,700 38,800 15,500 - 75,000
Copper 420 2,000 50 - 5,800
Lead 65 310 <10 - 800
Approximately 20 percent of the complete chrome
tanneries employ primary and/or secondary treatment of their
wastewater, and most of the remaining 80 percent of this
category of the industry utilize sewer sumps to remove solids
from their wastewater. As a result, a total of 68,100 (wet)/
11,800 (dry) metric tons per year of sludge are currently
being generated from these sources nationally.
3.3.3 Non-Hazardous Solid Waste. Miscellaneous
process solid waste is generated at a rate of 500 (wet)/
450 (dry) kg per 1000 equivalent hides processed, which
amounts to 8,400 (wet)/7,600 (dry) metric tons per year on
a national basis. This waste is composed of empty fiber
drums and paper bags, strings cut off the hides, and general
plant floor sweepings, and they do not contain consitutents
at potentially hazardous concentrations. Fleshings generated
by nearly all chrome tanneries are sold; they were, therefore,
not considered as a solid waste.
3.3.4 Factors Affecting Future Solid Waste Generation.
Air Pollution Control. Air pollution control devices
are used to remove particulates produced by the spray
finishing process and to collect buffing dust. The complete
chrome tannery typically.has a water-wash system to remove
particulates from the finishing spray booth exhausts. The
particulates removed are currently a relatively minor source
of solid waste. It is anticipated that gradual installation
of water-wash collection systems in the few tanneries which
do not currently (1974) utilize them, and retrofit installation
of the more efficient collection systems which will be required
by air pollution regulations in some areas, will not result
in an increase in finishing residues by 1977, but will produce
an estimated 5 percent increase by 1983.^3
Buffing dust is currently being effectively collected at a
majority of complete chrome tanneries. Wet scrubbers, cyclones,
and bag houses are all utilized in tanneries, but wet scrubbers
are relatively uncommon. Installation of adequate and/or
more effective collection devices at tanneries not currently
utilizing effective collection systems will not result in a
63
-------
significant increase in the quantity of buffing dust destined
for land disposal by 1977, but will produce an estimated
10 percent increase by 1983.23
Water Pollution Control. Treatment of process
wastewater generates a substantial quantity of solid waste.
Most tanneries (88) in this category currently provide
rudimentary screens and sewer sumps for the removal of
wastewater solids, and 19 tanneries provide a significantly
increased degree of solids removal through the use of
screening, primary clarifiers and/or secondary treatment.
When 1977 and 1983 effluent limitations are implemented,
it is estimated that 25 percent and 45 percent, respectively,
of the complete chrome tanneries will provide primary and/or
secondary treatment of their wastewater. This yields an
approximate 81 percent increase in sludge by 1983, most of
which will be due to primary treatment.
Industry Trends. It is estimated that production of
leather by complete chrome tanneries will increase 6.2
percent by 1977 and 17 percent by 1983 relative to 1974 /
This estimate takes into account population growth, growth
trends for related consumer industries, projected changes
in imports and exports, and the availability of the necessary
raw material. It does not take into account any changes in
U.S. trade policy.
3.3.5 Typical Plant Summary. The current (1974) and
projected (1977 and 1983) waste generation factors of process
solid waste and the various types and quantities of potentially
hazardous solid waste generated by a typical complete chrome
tannery are summarized in Table 17. As indicated in the
table, the generation factors for 1974 and 1977 are identical.
Finishing residues and buffing dust are the only wastestreams
expected to have a higher generation rate in 1983.
3.3.6 EPA Region and National Waste Summary. Table 18
presents the total quantity of process solid waste and the
types and quantities of potentially hazardous waste, including
their respective hazardous constituents (on a dry weight basis
only), currently (1974) produced by complete chrome tanneries.
Quantities projected for 1977 and 1983 are presented in Tables
19 and 20, respectively. The methodology used to develop
these and similar tables is discussed in Appendix D. As the
tables indicate, more than one-half of the potentially
hazardous solid waste generated by complete chrome tanneries
are produced in Regions I and V. It is also noteworthy
that the total quantity of potentially hazardous waste is
expected to increase 17 percent by 1977 and 53 percent by
1983 when compared to 1974. Most of these increases will be
69
-------
TABLE 17
WASTE GENERATION FACTORS FOR A COMPLETE CHROME TANNERY
(All units are kg pier 1000 equivalent hides)
1974 C 1977*
Waste Type
Total Process Solid Waste
Total Potentially Hazardous
Solid Waste
Trinmings ft Shavings
Unfinished Leather
Trim
Buffing Dust
Finished Leather
Trim
Finishing Residues
Wastewater
Screenings
Wastewater Sludge
(from sewer sump)
Source: SCS Engineers
* No nrnr!f>fiaina i
Total
Cr
Total
Cr
Pb
Total
Cr
Pb
Total
Cr
Pb
Total
Cr
Pb
Zn
Total
Cr
Pb
Total
Cr
Pb
Cu
"hanaAa
Wet
5,410
4,860
1,260
114
27
220
150
390
2,700
APA Awn
Dry
1,750
1,300
540
12.1
100
1.71
0.31
25
0.54
0.0018
200
4.2
0.055
45
0.079
0.165
0.016
90
0.38
0.016 .
300
7.4
0.07
0.51
*>(•«• A<4 ho(
1983
Wet
5,420
4,870
1,260
114
30
220
158
390
2,700
t-WAAri 1 «7
Dry
1,760
1,310
540
12.1
100
1.71
0.13.
28
0.59
0.002
200
4.2
0.055
47
0.083
0.17
0.017
90
0.38
0.016
300
7.4
0.07
0.51
A
and 1977 that would change the generation factors. Thus
they are identical.
70
-------
TABLE 18
TOTAL PROCESS MR) POTENTIALLY BAIAKDOOS WASTE
GENERATED IN 1974 BY COMPLETE CHROME TANNERIES
(metric ton* per year, wet and dry Basis)
EPA
Reaion(8)
I
II
XXX
XV i VI
V
vxx «
vxxz
XX
X
TOTAL
State (•)
ME.VT
HA
MM
MY
KJ
?A,VA,DB
TM,FL,LA
OH, MM
MI
HI
XL
HE,MO,UT
CA
AK.MA
TQtal
Process
Solid
Waste
Wet
11100
13400
8870
12900
2030
6)70
S040
5500
7880
21200
7110
1420
9820
192
11)000
Dry.
3490
4220
2800
4070
640
2010
1600
1740
2490
6680
2250
447
1100
60.8
35600
Total
Potentially
Hazardous
Wastes
Wet
10200
12300
8160
11900
1860
5860
4640
5060
7250
19500
6540
1300
9040
177
104000
Dry.
2770
3350
2220
3230
507
1590
1260
1380
1970
5300
1780
354
2460
48.2
28200
Trim and shavings
Total
Potentially
Hazardous Constituent
wet
2030
2450
16)0
2370
372
1170
925
1010
14 SO
3880
1300
260
1800
3S.3
19SOO
pry.
870
1050
697
1010
159
501 •
396
432
619
1660
559
111
772
15.1
8850
Chtomiun
19.5
23.6
15.6
22.7
3.57
11.2
8.88
9.68
13.9
37.3
12.5
2.49
17.)
0.34
199
Unfinished leather trimmings
Total
Potentially
Hazardous Constituents
tfet
183
222
147
214
33.6
106
83.7
91.2
131
351
118
23.5
16)
).19
1900
Dry.
161
195
129
188
29.5
92.7
73.4
80.0
115
308
104
20.6
143
2.80
1650
ChroniuEi
2. 75
3.33
2.21
3.21
0.50
1.59
1.26
1.37
1.96
5.27
1.77
0.35
2.45
0.048
28.0
Lead
0.20
0.24
0.16
0.24
0.037
0.12
0.092
0.10
0.14
0.39
0.13
0.026
0.18
0.0035
2.06
-------
TABLE 18
(Continued)
SPA
Reg ion (s)
I
II
III
IV « VI
V
VII t
VIII
IX
X
TOTAL
State (s)
NE.VT
MA
NH
NY
NJ
PA.VA.DE
TN.FL.LA
OH.MN
HI
HI
IL
NE.MO.UT
CA
AK.HA
Buffing dust
Total
Potentially
Hazardous Constituents
wet
43.4
52.6
34.9
50.7
7.97
2S.O
19.8
21.6
31.0
83.1
27.9
S.S6
38.6
0.76
443
Dry
40.2
48.7
32.3
46.9
7.38
23-2
18.4
20.0
28.7
77.0
23. 9
5.15
35.8
0.7
400
Chromium
0.87
1.05
0.70
1.01
0.16
0.50
0.40
0.43
0.62
1.66
0.56
0.11
0.77
0.015
8.8S
Lead
0.0029
0.0035
0.0023
0.0033
0.00053
0.0017
0.0013
oiOD14
0.0020
0.0055
0.0018
0.00037
0.0026
0.000050
0.029
Finished leather trim
Total
Potentially
Hazardous Const:
Net
354
428
284
413
64.9
204
161
176
252
677
228
45.3
315
6.16
3610
SSI
322
389
258
375
59
185
147
160
229
616
207
41.2
286
5.6
3280
•
Chromium
6.76
8.18
5.42
7.88
1.24
3.89
3.08
3.36
4.82
12.9
4.35
0.87 '
6.01
0.12
68.9
tuents
Lead
0.088
0.11
0.071
0.10
0.016
0.051
0.040
0.044
0.063
0.17
0.057
0.011
0.079
0.0015
0.90
Finishing residues
Tota
Pote
Haia
Net
241
292
194
282
44.3
139
110
120
172
462
155
30.9
215
4.2
2460
1
ntially
rdous
Dry
72.4
87.6
58.1
84.5
13.3
41.7
33.0
36.0
51.3
139
46.6
9.27
64.4
1.26
738
Const
Chromium
0.13
0.15
0.10
0.15
0.023
0.073
0.058
0.063
0.090
0.24
0.082
0.016
0.11
0.0022
1.30
ituents
Lead
0.27
0.32
0.21
0.31
0.049
0.15
0.12
0.13
0.19
0.51
0.17
0.034
0.24
0.0046
2.71
line
0.725
o.c:
O.Ci
O.C4
0.004
0.015
o.o::
o.c::
0.013
0.04$
o.o:?
0.0033
0.5i€
0.00044
0.26
to
-------
TABLE IB
(Continued)
EPA
RcgioMs)
I
II
ZIZ
IV t VI
V
VII t
VIII
IX
X
TOTAL
Stated)
•MP,VT
MA
MH
NY
HJ
PA.VA.DE
TR.FL, LA
OH, MM
HI
MI
II
HE,MO,UT
CA
ajc.wa
ttastewater screenings
Total
Potentially
Hazardous Constituents
wet
628
759
503
732
115
362
286
312
447
1200
404
80.3
558
10. 9
(400
Or*
145
175
116
169
26.6
83.4
66.1
72
103
277
93.2
18. S
129
2.52
1480
Chromium
0.61
0.73
0.49
0.71
0.11
0.35
0.28
0.30
0.43
1.16
0.39
0.078
0.54
0.011
6.17
Lead
0.025
0.030
0.020
0.029
0.0046
0.015
0.012
0.013
0.018
0.048
0.016
0.0032
0.022
0.00044
0.25
Wastewater sludge
Total
Potentially
Hazardous Constituents
Wet
6690
8100
5370
7810
1230
3860
3050
3330.
4770
12800
4310
857
5950
116
68100
DTi
1160
1402
930
1350
212
667
528
576
826
2200
745
148
1030
20.2
11800
Chromium
24.8
30.0
19.9
28.9
4.54
14.3
11.3
12.3
17.7
47.4
15.9
3f17
22.0
0.43
252
Lead
0.22
0.27
0.18
0.26
0.040
0.13
0.10
0.11
0.16
0.42
0.14
0.028
0.20
0.0038
a. as
Copper
1.58
1.91
1.27
1.84
0.29
0.91
0.72
0.79
1.13
3.02
1.02
0.20
1.40
0.028
16.1
Source* BCB Inginears
-------
TABLE 19
TOTAL moss MID PonvrxALLY BASA«DOOS WASTE* AHTXCIPATED TO BE
GEHBftATBD » 1*77 BY COMPLETE CHMMT TANKERIES
'(netric tens per year, wet and dry basis)
EPA
Region (s)
I
iz
III
XV t VI
V
VZI t
vzxx
IX
•I
TOTAL
State (a)
ME.VT
HA
NH
mr'
NJ
PA,VA,DB
TH.FL.LA
OH, MS
NX
MX
XL
RE«MO»UT
CA
AR.vV
Total
. Process
Solid
waste
wet
12300
14900
9890
14400
2260
7100
5(20
613
8790
23600
7930
1580
11000
214
130000
DT£
•3880
!4690
13110
1
4520
711
'• 2230
1770
1930
2760
7420
2490
496
3450
67.5
39600
Total
Potentially
Hasardous
Waste.
Wet
12700
15300
10200
14800
2320
7300
5780
6300
9040
24300
. 8160
1620
,
11300
221
121000
Or*
3110
3760
249C
3620
569
1790
1420
154*0
2210
5940
2000
398
2760
- 54.0
31700
Trim and shavings
Total
Potentially
Ratardous Constituent
wet
2160
2610
1730
2520
. 39S
1240
984*
1070
1540
4130
1390
276
1920
37.5
22000
Dry,
920
1110
736
1070
168
.528
418
456'
654
1760
590
117
815
16.0
9450
Chromium
70.8
25.1
IS. 7
24.2
3.81
12.0
9.47
10.3
14.8
99.7
13.4
2.66
18.5
0.36
211
Unfinished leather trismings
Total
Potentially
Hasardous Constituents
Wet
195
236
156
227
35.7
112
88.6
'96.8
139
373
125
24.9
173
3.39
1990
Dry
171
206
137
199
31.3
98.3
77. -8
84.8
122
326
110
21.8
152
2.97
1740
Chroaiun
2.93
3.54
2.35
3.42
0.54
1.69
• 1.34
1.46
2.09
S.60
1.88
0.38
2.60
0.051
29.9
Lead
0.214
0.26
0.17
0.25
0.019
0.12
0.098
0.11
0.15
0.41
d.14
0.027
0.19
(.0037
2.18
-------
TABLE 19
(Continued)
"A
S=5ion<»)
I
II
:u
IV « VI
V
VII I
VIII
IX
X
TOTAL
State (s)
MS.VT
MA
NH
NIT
HJ
PA,VA,DG
TM,Ft,IA
OH,MN
HI
HI
II,
SE,«0,UT
CA
A*,t»
flufflne dust
Total
• Potentially
Hazardous Constituents
tfet
4.7
56-. S
37.4
54.4
8.56
26.9
21.3
33.2
33. i
89. J
10.0
5.97
41. S
1.11
47«
23C
43
52. 6
34.9
50.7
7.97
'25.0
19.8
21.6
31.0
B3.1
27.9
5. So
38.6
O.W
443
Chr enter.
0.92
1.11
0.74
1.07
0.17
O.S3
0.42
0.46
0.65
1.76
0.59
0.12
0.12
e.oi6
8.3«
bead
0.009
0.0037
0.0024
0.0036
1.00056
0.0018
0.0014
0.0015
O.G022
0.0058
0.0020
1.00039
0.0027
.000052
0.031
Finished leather trial
Total
Potentially
Hazardous Constltuenta
Wet
377
456
302
43»
69.0
217
172
187
2«B
720
242
48.2
395
6.55
3840
SSI
341
413
274
398
62.5
191
156
170
243
653 .
219
43.7
303
5.94
3480
Chromium
7.24
8.76
5.81
8.45
1.33
4.17
3.30
J.*0
5.16
13.9
4.66
0.93 •
6.44
0.13
73.9
Lead
0.093
0.11
0.075
0.11
0.017
0.054
0.043
0.046
0.067
0.18
0.060
0.012
0.083
1.0016
0.95
Finishing residues
Total
Potentially
B«e.*lo\:s
Wet
257
312
207
300
47.2
148
117
128
184
493
16«
33.0
229
4.48l
2630
D££
77.2
93.5
62.0
90.1
14.2
44.5
35.2
38.4
54.7
148
49.7
9.89
68.6
1.34
787
•• Constituents
Cranium
.0.13
0.16
0.11
0.16
0.025
0.078
0.061
0.067
0.096
0.26
0.087
0.017
0.12
0.0023
1.37
X.3Cd
0.28
0.34
0.23
0.33
0.052
0.16
0.13
0.14
0.20
0.54
0.18
0.036
0.25
0.0049
2.87
Zirc
0.021
0.033
0.022
0.031
0.0050
0.016
0.012
0.013
0.019
0.052
0.017
0.0035
0.024
1.00047
0.27
-4
Ui
-------
TABLE. 19
(Continued)
BPA
Rcoion(s)
z
11
zzz
IV t VI
V
VII t
VIII '
II
X
TOTAI
State (•)
KE,VT
HA
KH
HY
HJ
PA.VA.0B
m.ri.LA
GB.NH
MI
HI
IL
tlE.KO.UT
CA
AH .HA
.
Wastemter «er*enlnw
TOtel
Potentially
Rasardoue Constituents
*et
•66
806
534
777
122
384
304
331
47.1
197*
428
65.3
S«2
11.4
:«T»O
SSL
154
187
124
180
28.3
89.0
70.3
7C.8
118
2»C
•9.4 -.
1».8
137
t.89
1MO
Chrcaium
0.64
0.78
O.S2
0.7S
8.12
0.37
8.29
0.32
0.4«
1.23
0.41
0.082
O.S7
0.011
i.S7
£«£
0.017
0.012
0.021
0.031
0.9049
0.01S
0.012
0.013
0<019
0.051
8.011
0.0034
0.024
0.00047
0.29
MMtemtM ilu&a*
ifotal
Potentially
Raxardoaa * conn
Net
7710
*330
«1BO
8990
1410
4440
3S20
3830
5490
14700
49400
987
(890
134'
B3008
££
1348
1620
1070
15CO
245
769
«09
•64
9S2
2S60
8S9
171
1190-
23.2
13680
Chrcnium
28.5
34. >
22.9
33.2
S.32
16.4
13.0
14^2
20.3
54.8
18.3
3.65
25.3
0.90
290
ituente
L«ed
0.21
0.31
0.20 .
0.30
0.047
0.15
0.12
0.13
0.10
0.49
O.U
,0.033
0.23
0.0044
2.59
Copper
1.62
2.20
1.46
2.12
0.33
1.05
0.63
0.91
1.30
3.40
1.17
0.23
1.62
0.032
16 ;6
-------
TABLE 20
Tona PROCESS ABD POTERTIAU.Y HAZARDOUS HASTE ANTICIPATED TO
GENBMTBD ZH 1983 BY COMPUVR CRKMB TANNERIES
(••trie tana per year, wwt and dry basis)
EPA
Reoion»
X
,
II
zzt
IV ( VI
V
Vtl •
VtZI
IX
X
TOTAt
1
Stated!
ME,VT
MA
HH
HY
NJ
PA,VA,DB
TO, PL. LA
OH.KN
HZ
NZ
IL
«B,NO,m
CA
AX .Ml
, Total
Process
, Solid
• Haste
! Sgt
1SSOO
19940
11200
19200
3020
9490
7520
•190
11100
31500
10COO
2110
14600
287
16TOOO
pry.
Isiio
[6180
.4100
3960
. 936
'2940
!2330
2S40
3640
9770
3190
«S4
4540
88.9
snoo
! Total
j Potentially
; Hax*
Hast
Wet
' 15400
1 18700
; 12400
1 18000
i 2830
1
8900
7040
7680
11000
29500
9930
1980
13700
269
158000
rdous
e=
Dry.
4260
5150
3420
4970
781
2450
1940
2120*
3040
8150
2740
545
3790
74.1
43400
Trin and shavings
Total
Potentially
Hazardous
Wet
2370
2870
1900
2770
435
1370
1080
1180
1690
4540
1530
304
2110
41.3
24200
Dry.
1020
1230
816
1190
186
586
464
506
725
1950
654
130
904
17.7
10300
Chromium
22.8
27.6
18.3
2C.7
4.19
13.2
10.4
11.4
16.3
43.7
14.7
2.93
20.3
0.40
233
Unfinished leather triiminos
Total
Potentially .
. Met
; 214
259
' 172
250
39.2
' 123
97.6
' 106
153
410
138
27.4
190
3.72
2180
Dry.
188
228
151
220
34.5
108
85.9
93.6
134
360
121
24.1
167
3.28
1920
Chror.iun
.22
.89
.58.
.75
.59
1.85
1.47
1.6
2.29
6.16
2.07
0.41
2.86
0.056
32.8
Lead
0.23
0.28
0.19
0.27
0.043
0.14
0.11
0.12
0.17
0.45
0.15
0.030
0.21
0.0040
2.40
-------
TABLE 20
(Continued)
SPA
Region (8}
t
XX
XXX
XV • VI
V
VXX-a .
VIII
n
.. X
tana
Stated).
NE.VT
HA
NH
MT
. tu
M.VA.OI
18.rL,IA
ORfHN
MI
WI
XL
ra*M(OT
c*
M.MA.
!
Buff ino dust
Potentially
Hazardous
Wet
54.7
66.2
43.9
63.8
10.0
31.5
25.0
27.2
3f.O
105
35.2
7.00.
,40. •
o.9s
SSI
DTJt
51.5
62.3
41.3
60.1
9.44.
30.0
23. S
2S.6
36.7
98.5
33.1
6.59
«M
o.to
S2S
Constituents .
ChrOBittlQ
1.1
1.34
0.89
1.30
0.20
0.64
O.S1
o.ss
0.79
2.11
0..7?
0.14
0.99
0.01*
11. S
Lead
0.0036
0.0044
0.0029
0.0042
0.00067
0.0021
0.0017
' 4.0018
0.0026
0.0070
0.0029
0.00047
, 0.0032
0.000063
0.037
Finished leather trio
Total ,
Potentially |
Raiardous . ; Consti
wet
414
500
332
402
7S.O
230
109
206
29S
791
266
52.9
360
7.20
4220
2St
1 377
456
302
439
69.0
217
172
: 107
;s
- 242
40.2
33S
6.55
3040
' Chrorciun
7.88
9.54
6.33
9.20
1.45
4.54
3.60.
3.92
5.62
15.1
S.I.
1.01
7.01
0.14
00.3
tuents
Lead
0.10
0.13
0.083
0.12
0.019
0.059
0.047
0.051
0.073
0.20
0.066
0.013
0.092
0.0010
1.05
riniehir.9 residues
1 TOt)
• ?0t(
Has
Wet
294'
356
236.
343
34.0
170
•134
146
110
S63
»M
37.7
262
S.1X
3000
11 i
antially
irdeus " • Car.st
Drjr
. 88
107
71.0
103
16.2
51.0
40.4
44
63.1
169.
56 .'9
11.3
76.7
.1.54
903
Chrosi-jr.
' 0.15
0.19
0.12
«.10
0.020
0.009
0.071
0.077
0.11
0.23
0.099
0.020
0.14
0.0027 ,
LSI
Itucr.ts
-aid
0.32
' 0.39
0.26
0.38
0.059
0.19
0.15
0.16
0.33
0.62
0.21
0.041
0.29
0.0056
3.21
Zinc
0.031
0.037
0.025
0.034
O.OOS6
0.018
0.014
0.015
0.022
0.059'
0.020
0.0039
0.027
0.00053
O.il
-------
TABLE 20
(Continued)
SPA
Region (•)
I
11
III
IV C VI
V
VII t
VZIt
«
X
TOTAL
Stated)
ME,VT
MA
tra
NY
NJ
PA.VA.DB
TN.FL.IA
OH,HN
MI
MI
IL
NE,MO,UT
CA
AR.NK
Wastevater screenings
Total
Potentially
Hazardous Constituents
Wet
715
890
590
858
135
424
335
366
524
1410
473
94.1
654
It.t
7500
Dry,
169
204
136
197
31.0
97.3
77.1
84
120
323
109
21.6
150
2.94
1720
Chromium
0.71
0.86
0.57
0.83
0.13
0.41
0.32
0.35*
0.51
1.35
0.46
0.091
0.63
0.012
7.22
Lead
0.029
0.036
0.024
0.034
0.0054
0.017
0.013
0.015
0.021
0.056
0.019
0.0038
0.026
0.00051
0.30
Wastewater sludge
Total ,
Potentially
Hazardous Constituents
Met
11400
13800
9130
13300
2090
6560
S190
5660
«110
21800
7320
1460
10100
198
116000
Dry.
1970
2380
1580
2300
361
1130
898
979
1400
3770
1270
252
1750
34.3
20100
Chromium
42.2
51.0
33.8
49.2
7.73
24.3
19.2
21.0
30.1
80.7
27.1
5.40
37.5
0.734
429
Lead
0.37
a. 4$
0.30
0.44
0.069
0.22
0.17
0.19
0.27
0.72
0.24
0.048
0.33
0.0065
3.»2
Copper
2.69
3.25
2.16
3.13
0.49
1.55
1.23
1.34
1.92
5.14
1.73
0.34
2.39
0.047
27.4
SOUR* i 80S Engineers
-------
due to wider use of primary and secondary wastewater treatment
with attendant increased sludge generation as noted in
Sections 3.3.2 and 3.3.4.
3.4 Vegetable Tannery
3.4.1 Plant Operations. This portion of the industry
includes those plants which convert cattlehides to leather
using the vegetable tanning process.
Brine cured, prefieshed cattlehides are first soaked
after receipt at the tannery to return moisture tb the
hides. The hides are then treated with lime and Na2S, NaHS,
and soda ash to chemically destroy the hair folicles. The
hair is then removed mechanically from the hides, aster
which the flesh is! removed from the inner side of; the hide.
Following the fleshing operation, the hides are bftted (treated
with an enzyme);, pickled (treated with acid) , and then tanned.
The tanning process involves soaking the hides in.a slurry
of vegetable extracts for approximately two weeks^ i
The hides are then bleached in. order to lighten the
surface colors, Subsequently treated with fat^liqubrs (animal
and vegetable oils)" in. order to return some of. the natural
flexibility to the hide fibers, and then; dried. The resulting
leather is mechanically split to obtain a uniform thickness
and physically {conditioned to achieve the desired degree of
flexibility. The^ leather may then be buffed,to remove
unsightly imperfections and, trimmed to remove ragged edges
in final preparation for sale. A typical vegetable tannery
processed 151,000 equivalent hides in 1974.*
Figure 6 is. a process, flow diagram for a typical
vegetable tannery indicating the types and quantities of
raw materials and products involved, the basic production
operations performed, and the types and quantities of waste
resulting from the production process.
3.4.2 Process. Solid Waste.
Fleshings.* An average of approximately 70 percent of
the cattlehides received are prefieshed at the slaughterhouse.
Any one plant,may use prefleshed hides and hides which have
not been fleshed, or only one type. As a result, the quantity
of fleshings generated by plants vary widely. However, virtually
all vegetable-tanners -find it necessary tb fleSh hides which
they have received; thus, some fleshings are generated by
virtually all vegetable tanneries. A typical Vegetable
tannery generates fleshings at a rate of 3,000 (wet)/700 (dry)
kg per 1000 equivalent hides processed. Annually 9,500 (wet)/
2,200 (dry) metric tons of fleshings are produced. Analysis
of one sample collected from the pits below the fleshing
indicated that this wastestream is not potentially hazardous.
80
-------
FIGURE 6
PROCESS PLOW DIAGRAM
TYPICAL VEGETABLE TANNERY
(All units are kg/1000 equivalent hides on a dry weight basis
except solid wastes which are given on a wet/dry basis)
CURED CATTLE HIDES
(13.100)
MATERIALS AODED 1
•X *
LIME (1800) 1 LIME
SODA ASH ( 20) I FLESH
1 u
(NH4)_S04 . (500 A BATE
NACL (aoo) .PICKLE
ACIDS . (3OO) jS^ TAN
HEXAMETAPHOSPHATE (30O> ^T \
TANNING AGENTS (loon) ^ 4
SYNTANS (400) 9LEACH
FILLERS (1700) _ OIL
NAHC03 ( 50) ^* \
MISC. •aso^-X^ ^
N ^-^^*"**"^ DRV
OILS OOOjV,,**'11^*^ SPLIT
MISC. HOOtJ CONDITION
BUFF
TRIM
I 1
' HIDE TRIM (ISO) J
>Jk MAIR ( 7OO1 li
*t\ FLESH INir.S 9
H (3000/700)
1
FICKLED BP' ' tps a)
(1200)
I
1
_ 1
WASTE SPLITS & TRIM 1
I
1
«| fc
MISC.
PROCESS
SOLID WASTE
(390/300)
AOOX12AOI J
BUFFING DUST (!OO/9OfcJt I?
GOOD SPLITS («SO) ^^
1 PFPAL SALES
V WASTEWATER
LEATHER ' T
(10,500) s
S
T
1
ECONDARY
(700/1*0) _.
)0/1S»L J
T
DIRECT
DISCHARGE
PROCESS SOLID WASTE TO
SANITARY LANDFILL OR
OPEN DUMP
(12.200/2700)
81
-------
Haste Splits and Trimmings. Waste splits and trimmings
are composed of leather which is removed from the tanned
hide in order to obtain a uniform thickness and satisfy
purchaser's cutting requirements. A typical vegetable
tannery generated 1,400 (wet)/I,200 (dry) kg per 1000
equivalent hides processed which amounts to 4,400 (wet)/
3,800 (dry) metric tons per year nationwide. This waste
material is primarily animal protein which has been
cross-linked by vegetable tanning agents in order to eliminate
its susceptibility to bacteriological decomposition. Analysis
of three samples collected from below the splitting machines
and from fiber barrels in the trimming department indicated
that this wastestream is not potentially hazardous.
Buffing Dust. A typical vegetable tannery generates
100 (wet)/90 (dry) kg per 1000 equivalent hides processed
which amounts to 320 (wet)/290 (dry) metric tons annually
nationwide. Buffing dust is generated in sanding operations
performed to remove certain imperfections fromthe surface
of the leather. Analysis of three samples taken from the
buffing dust collection equipment indicated that this
wastestream is not potentially hazardous.
Wastewater Screenings. Virtually all vegetable
tanneries perform some kind of screening of their Wastewater.
prior to discharge or further treatment. A representative
vegetable tannery generates 2,800 (wet)/140 (dry) kg of
screenings per 1000 equivalent hides processed. Samples of
screenings, which were composed mostly of hair and flesh,
were collected from the wastewater screens at two tanneries.
Analysis of the two screening samples collected indicated
that this wastestream is not potentially hazardous.
Wastewater Treatment Sludges. A representative tannery
produces 7,000 (wet)/350 (dry) kg of sludge per 1000
equivalent hides processed which amounts to 22,100 (wet)/
1,100 (dry) metric tons annually nationwide. Sludge samples
were collected from lagoons at three vegetable tanneries.
Analysis of these samples indicated that this wastestream
is not potentially hazardous.
Miscellaneous Process Solid Waste. Miscellaneous
process solid waste is generated at a rate of 350 (wet)/
300 (dry) kg per 1000 equivalent hides processed, which oh
a national basis amounts to 1,100 (wet)/950 (dry) metric
tons per year. This waste is composed of fiber drums, paper
bags, wooden barrels in which the pickled skins are received,
and general plant floor sweepings, and they do not contain
constituents at potentially hazardous concentrations.
32
-------
3.4.3 Factors Affecting Future Solid Waste Generation.
Air Pollution Control. Most vegetable tanneries utilize
moderately effective equipment to collect the leather dust
which is produced by buffing, and this situation is not
expected to change by 1977. However, it is anticipated
that by 1983, retrofit installation of more effective buffing
dust collection devices at vegetable tanneries will result
in an increase of 15 percent in the quantity of buffing
dust destined for land disposal.23
Water Pollution Control. Screenings and wastewater
treatment sludges destined for land disposal are currently
generated as a result of wastewater treatment systems at
an average vegetable tannery. Since Federal effluent
limitation guidelines are currently under litigation, it
is anticipated that the type and extent of wastewater
treatment at vegetable tanneries will not change significantly
by 1977. However, it is anticipated that the improved
quality of wastewater discharged from vegetable tanneries
as the result of future Federal and State water pollution
control regulations will result in a 15 percent increase
in the quantity of vegetable tannery wastewater sludges
destined for land disposal by 1983.
On the other hand, it is anticipated that efforts will
be made to reduce chemical usage in vegetable tanneries by
1983. It is estimated that chemical conservation techniques
will nullify the increase in the quantity of sludge to be
generated by 1983 as a result of water pollution control
regulations.
Industry Trends. Vegetable t.anned leather is utilized
primarily for footwear. It is assumed that the growth and
consumption of footwear in the United States will be
approximately equal to the growth in population, which is
approximately 1 percent per year. It is also assumed that
the growth rate of the penetration of imported footwear
will increase 3 percent per year through 1983.2 Therefore,
the production of vegetable tanned leather in the United
States is expected to decrease at the rate of 2 percent
annually through 1983.
3.4.4 Typical Plant Waste Summary. The current (1974)
and projected (1977 and 1983)generation rates of process
solid waste in kg per 1000 equivalent hides processed by a
typical vegetable tannery, are as follows:
1974 and 1977 1983
Wet Dry Wet Dry
12,200 2,700 13,000 2,750
83
-------
As indicated, a typical vegetable tannery generates
more total process solid waste per 1000 equivalent hides
on a wet weight basis than any other type of tannery, although
none of the waste is potentially hazardous.
3.4.5 EPA Region and National Waste Summary. Table 21
presents the total quantity of process solid waste currently
(1974) produced, and the quantities projected for 1977 and
1983. It is noteworthy that vegetable tanneries produce more
process solid waste on a national basis than any other type
of tannery, except complete chrome tanneries.
3.5 Sheepskin Tannery
3.5.1 Plant Operations. The major raw material of
sheepskin tanneries is imported, pickled sheepskins. However,
some sheepskin tanneries which utilize fresh or cured
sheepskins as their raw material have beamhouses where
the hides are soaked, fleshed, and unhaired in preparation
for tanning.
Pickled sheepskins are normally received by the tannery
in 20 kg wooden barrels. The pickled skins are removed from
their shipping containers and placed in rotating wooden drums
in which they are degreased, normally with a solvent degreasing
system, and less frequently with water. In solvent degreasing
systems, the solvent is recovered and sold to be reprocessed.
In water degreasing systems, a detergent solution removes the
grease from the skins.
The degreased skins are then chrome tanned with a basic
chromic sulfate solution. In some cases, formaldehyde is
also used in the tanning process, which decreases the amount
of chromium required. Most of the formaldehyde is incorporated
into the leather with excess discharged as part of the wastewater.
If the skins require fleshing, they are removed from the
tanning drums and mechanically fleshed. Following fleshing,
or without being removed from the tanning drums if fleshing
is not required, the skins are retanned with vegetable
or synthetic tanning agents, colored with dyes and pigments,
and fatliquored. The fatliquoring process involves the
addition of oils to lubricate the fibers of the skins so
that after drying they will be able to slide over one
another. In addition to regulating the pliability of the
leather, the fatliquor increases its tensil strength.
Following fatliquoring, the skins are stretched on a
metal frame and then dried in an oven. The resulting leather
is conditioned mechanically to impart the desired degree of
softness. The skins are then mechanically sanded (buffed)
to remove imperfections in the grain surface, or to produce
the desired nap if the leather is to be a suede. Finally,
the leather is trimmed to remove ragged edges and packaged
for shipment to the customer. A typical sheepskin tannery
processed 200,000 equivalent hides in 1974.
3/1
-------
TABLE 21
TOTAL PROCESS AND POTENTIALLY HAZARDOUS WASTE
GENERATED BY VEGETABLE TANNERIES
(metric tons per year, wet and dry basis)
CO
ui
EPA
Reg ion ( s)
III
V
IV
VI, VIII «
X
TOTAL
State(s)
PA
VA,WV,MD
IN, OH
XY
GA,TN,NC
OR,TX,MO
1974
Total
Process
Solid
Waste
Wet
9890
14200
1180
5480
7740
1230
39700
Dry.
2190
3140
261
1210
1720
272
' 8790
1977
Total
Process
Solid
Waste
Wet
9300
13300
1110
5160
7280
1160
37300
Dry
2060
2950
246
1140
1610
256
8260
1983
Total
Process
Solid
Waste
Wet
8780
12600
1050
4870
6880
1090
35300
Dry
1860
2660
222
1030
1460
230
7460
Sourcei SCS Engineer*
-------
Figure 7, a process flow diagram for a typical
sheepskin tannery, indicates the basic production operations
performed, the types and quantities of raw materials and
products involved, and the typfs and quantities of waate
products resulting from proilurr ion pro
3.5.2 Potentially Hazardous Solid Haste. As indicated
in Figure 7, several kinds of solid waste is generated.
The potentially hazardous wastestreams are discussed below.
Fleshings. Mechanical fleshing of sheepskins to
remove excess fatty material from the flesh side of the
skin is normally performed immediately following chrome
tanning. The typical sheepskin tannery using pickled
sheepskin as the raw material generates 1,200 (wet)/300 (dry)
kg of fleshings per 1000 equivalent hides processed. On
a national basis, sheepskin tanneries produce 2,990 (wet)/
747 (dry) metric tons of fleshings per year.
Chrome fleshing sample's were collected from below
sheepskin fleshing machines at three tanneries. Although
the fleshings consist primarily of animal fat and protein,
analysis indicated that they also contain 4,030 (wet)/i6,300
(dry) mg/kg chromium.
Buffing Dust. Mechanical sanding (buffing) of sheepskin
leather produces 100 (wet)/90 (dry) kg of fine leather dust
per 1000 equivalent hides processed, which on a national
basis amounts to 140 (wet)/125 (dry) metric tons per year.
Samples were taken from the buffing dust collection devices
at three sheepskin tanneries. Analysis of these samples
indicated the presence of hazardous constituents as followst
Avg. concentration Concentration range
(mg/kg) (mgAg)
Constituent Wet Dry .Dry
Chromium 17,500 19,000 6,700 - 31,000
Lead 620 670 340 - 990
Copper 980 1,070 130 - 2,000
Zinc 280 310 Not de— 620
tected
Leather Trim. Sheepskins are normally trimmed befbre
packaging to remove the ragged edges from the skins. This
trimming operation produces 170 (wet)/I40 (dry) kg of leather
trim per 1000 equivalent hides processed at a typical
sheepskin tannery, which on a national basis amounts to
424 (wet)/349 (dry) metric tons per year. Samples were
collected from the fiber drums in the trimming departments
of two sheepskin tanneries. An analysis of these samples
86
-------
FIGURE 7
PROCESS PLOT* DIAGRAM
TYPICAL SHEEPSKIN TANNERY
(All units are kg/1000 equivalent hides on a dry weight basis
except solid wastes which are given on a wet/dry basis)
PICKLED SHEEPSKINS
MATERIALS
ADDED
NACL (8201
SOLVENT (RECYCLED)
TANNING AGENTS ( 90O 1
MISC. (200)
ACIDS
DYES
FATLIOUORS
RETAN MATERIALS
MISC.
(140)
( 70)
( 120)
(200)
(2400)
DECREASE -
CR TAN _
1 FLESH |_
RETAN
COLOR
IFATLIOUOR
i
DRY
CONDITION
BUFF
TRIM
1
1-
1
1
A
T
i
i
i
i
i
-ta
A
I
» GREASE SOLD
(200)
FLESHINGS
( 1200/300)
MISC. PROCESS
SOLID WASTES
(4SO/350)
iUFFING DUST (S6/SO)
TRIM (170/140)
,
"
-•
1
g|
LEATHER
(1200)
KASTEWATER
I
I SCREENING]
r
H
WASTEVATER
TO SEWER
(SOLIDS-2600)
PROCESS SOLID WASTE.
TO SANITARY LANDFILL
(2110/890)
87
-------
indicated the presence of the following hazardous
constituents:
Avg. concentration Concentration range
(rag/kg) (mg/kg)
Constituent Wet Dry Dry
Chromium 37,000 44,000 12,000 - 76,000
Lead 280 330 94 - 560
Copper 140 170 32 - 300
Wastewater Screenings. Essentially all sheepskin
tanneries screen their wastewater prior to discharge or
further treatment. A typical plant generates 230 (wet)/
50 (dry) kg per 1000 equivalent hides processed, which on
a national basis amounts to 574 (wet)/125 (dry) metric tons
per year. A sample was taken from the wastewater screens
at one sheepskin tannery. The screenings are composed
primarily of small pieces of leather which are torn off the
sheepskins at various points in the production process, and
contain the following hazardous constituents:
Avg. concentration
(mgAg)
Constituent Wet Dry
Chromium 7;200 33,000
Copper 50 220
3.5.3 Non-Hazardous - Solid Waste. Miscellaneous process
solid waste is generated at a rate of 390 (wet)/350 (dryj
kg per 1000 equivalent hides processed, which on a national.
basis amounts to 1,130 (wet)/870 (dry) metric tons per year.
This waste is composed of fiber drums, paper bags* wooden
barrels in which the pickled skins are received, and general
plant floor sweepings, and they do not contain constituents
at potentially hazardous concentrations.
3.5;4 Factors Affecting Future Solid Waste Generation.
Air Pollution Control. The only significant source of
air pollution from sheepskin tanneries is leather dust which
is generated by the buffing operation, and this is currently
(1974) being controlled adequately by most tanneries of this
type. Retrofit installation of more efficient collection
systems which may be required by air pollution control
regulations in certain areas are not expected to significantly
increase the quantity of buffing dust destined for land
disposal by 1977. However, it is estimated that more
efficient buffing dust collection systems will result in a
88
-------
10 percent increase in buffing dust destined for land
disposal by 1983."
Water Pollution Control. The only solid waste currently
generated as a result of wastewater treatment at most
sheepskin tanneries is screenings. Since Federal effluent
limitation guidelinesand pretreatment standards for the
tanning industry are currently under litigation, it is
anticipated that wastewater treatment at sheepskin tanneries
in 1977 will be limited to screening. However, it is
estimated that by 1983, as surcharges and pretreatment
guidelines are established, approximately 10 percent of
sheepskin tanneries will be using primary pretreatment to remove
solids from their wastewaters. Although this figure may
seem low, it should be noted that the only likely candidates
for primary pretreatment are the sheepskin tanneries with
high suspended solids in their wastewater, i.e., those few
operations with beamhouses . It is estimated that this will
result in the generation of 1,500 (wet)/ISO (dry) kg of sludge
per 1000 equivalent hides processed, which on a national
basis will amount to 236 (wet)/24 (dry) metric tons per year
(1983) from the 10 percent of sheepskin tanneries with
primary pretreatment.
Industry Trends. It is estimated that the production
of sheep leather will decrease at the rate of 5 percent per
year through 1983.2 This decrease in sheepskin leather
production is expected to result from increased importation
of sheepskin leather products. The supply of sheepskins
for tanning is decreasing as a result of these raw materials
being processed in the countries of origin.
3.5.5 Typical Plant Waste Summary. Table 22 presents
the current (1974) and projected(1977 and 1983) generation
factors for process solid waste and the various types of
potentially hazardous solid waste generated by a typical
sheepskin tannery. The increase in potentially hazardous
solid waste per 1000 equivalent hides anticipated for 1983
is primarily the result of the installation of a sewer sump
by a typical sheepskin tannery to remove wastewater solids
in order to reduce sewer surcharges.
3.5.6 EPA" Region and National Waste Summary. The
current (1974) quantity of process solid waste and the •
types and quantities of potentially hazardous waste, including
hazardous constituents, generated on an EPA Region and national
basis are presented in Table 23. Quantities projected for
1977 and 1983 are indicated in Tables 24 and 25 , respectively.
Examination of these tables shows that sheepskin tannery
waste generation is concentrated in Regions I and II. In
89
-------
TABLE 22
WASTE GENERATION FACTORS FOR A TYPICAL SHEEPSKIN TANNERY
(All units are kg per 1000 equivalent hides)
waste Type
Total Process Solid Waste
Total Potentially Haiardous
Solid Waste
Chrome Fleshing
Unfinished Leather
Trim
Buffing -Dust
Wastewater
Screenings
Wastewater Sludge
(from sewer sump)
Source: SCS Engineers
* ' Mo Tn*nr?A«ain« e
Total
Cr
Total
Cr
Cu
Pb
Total
Cr
Pb
Cu
Sn
Total
Cr
Cu
Total
Cr
Cu
Pb
•IkJUUCAB
1974 t
Wet
2,100
1,660
1,200
170
56
230
._
•vtt' AI>»^»«»
1977*
Dry
•90
540
300
4.8
140
0.63
0.048
0.024
50
0.98
0.035
0.055
0.016
50
1.66-
0.012
III
•»A
-------
TABLE 23
TOTAL PROCESS AMD POTENTIALLY HAZARDOUS HASTE
GENERATED IH 1974 BY SHEEPSKIN TANNERIES
(netxlc ton* pec year, net and dry baaia)
EPA
HvjlonUl
I
(I
(II
IV 1 VI
V I VII
TOTAL
StatQtB)
Mb. Ml
MA
•:v,::j
PA
.-L.TX
HI."!-:, i A
.
T'.l.il
Process
Solid
Vasto
Wot
1550
1440
1800
16S
88.6
219
»CO
Dry
603
608
757
69.1
17.4
92. «
2220
Tnt.il
Potentially
Haiardous
Haate>
Kgt
1220
1110
1410
110
69.6
172
4110
Or*
196
169
460
42.1
22.7
56.2
1150
Chrunu Clculiinuti
Total
Potentially
Hazardous Constituent
wet
881
820
1020
94.0
50.4
125
2990
pry.
220
205
255
21.5
12.6
11.2
747
Chromium
1.52
1.28
4.08
0.18
0.20
0.50
12.0
Un 1 1 n i •hjvi ]»%t9«.*F ^pi^*nif«a4
Total
Potentially
Hazardous Cons
Hat
125
116
145
13. 1
7.14
17.7
424
Dry.
101
9S.fi
119
11.0
S.88
14.6
349
Chromium
0.46
0.41
0.54
0.049
0.027
0.066
1.57
itcents
Copper
0.035
O.C11
0.041
0.0017
0.0020
0.035?
. 0.12
Leai
o.o:~
O.Ole
o.orc
0.0019
O.OOl.i
0.00:4
0.059
r.?A
i'eqionU)
I
II
XII
IV t VI
7 t VII
T07AI.
State IB)
MB. Nil
KA
»Y.NJ
PA
PL.TX
Hl.MJi.lA
Buffing duet
Total
Potentially
Hazardous Constituents
Ket
41.1
18.2
47.7
4.18
2.15
5.82
140
Dry.
36.7
J4.2
42.6
3.92
2.10
5.20
125
Chromlua
0.72
0.67
0.83
0.077
0.041
0.10
2.44
Lead
0.026
0.024
0.010
0.0027
0.0015
0.0016
0.087
Copper
0.040
0.019
0.0«7
0.0041
0.002)
0.0057
0.14
line
0.0115
0.011
0.011
o.ooia
0.00066
0.0016
0.039
waetewater acreeninos
total
Potentially
Hatardous Constituents
Wet
169
187
196
18.0
9.66
23.9
574
2DL
16.7
14.2
42.6
1.92
2.1
5.2
125
ChrcMJun
1.2!
1.11
1.41
0.11
0.070
0.17
4.13
Casper
O.OOS4
O.OOT4
0.0008
0.00090
O.OOi^i!
o.ooi:
0.0:9
Sourcei tCS Engineers
-------
TABLE 24
TOTAL PROCESS AND POTENTIALLY IIAXAROOUS KASTU ANTICIPATED TO BB
GENERATED IN 1977 BY SHEEPSKIN TANNERIES
(ooirlc tons pec year, vet- and dry basis)
a-k
"".iiori (s)
I
II
III
IV t VI
V-t VII
TOTAL
Ctato (s)
XK,NII
KA
:.v,:u
PA
!•:..«
UI.MM.IA
Total
Process
Solid .
Vaste i
HBB
1130
1240
1540
141
76
198
4520
Dry
562
521
651
59.6
12
79.2
1910
Total
Potentially
Hazardous
Waster
tfot
1040
914
1210
111
59.6
147
3540
pry.
J41
us*
393
36.2
19.4
48.1
1160
Chroma fleshings
Total
Potentially
Hazardous Constituent
Wot
757
706
878
80.4
41.2
107
2*70
SEX
189
176
210
20.1
10.8
26.7
•43
Chromium
1.03
2.82
3.51
0.32
0.17
0.43
10.3
Unfinished leather triisainos
Total
Potentially
Hazardous Cons
wot
107
100
124
11.4
6.12
15.1
364
pry.
88.3
82.3
102
9.18
5.04
12.5
300
Chronium
0.40
0.17
0.4C
0.042
0.023
0.056
1.35
.ituents
Copper
0.030
0,028
0.035
0.0032
0.0017
0.0042
0.10
tead
0.015
0.04
0.017
O.OOlf
0.00086
0.0021
0.077
vo
N>
EPA
I
II
in
IV t VI
V t VII
TOTAL
State (3)
NK.KII
MA
NV.IU
PA
FL.TX
NI.MN.IA
Baffin* dust
Total
Potentially.
Hasardous Constitu
35.3
12.9
41.0
3.75
2.02
4.98
120
31.6
36.6
3.35
1.80
4.45
107
Chrmitaa
0.62
O.S8
0.72
0.066
0.015
0.087
2.10
0.022
0.020
0.025
0.0023
0.0012
0.0031
0.074
Hit!
Copper
0.035
0.012
0.040
0.0037
0.0020
0.0049
0.12
0.0099
0.0092
0.012
0.0011
0.00057
0.0014
0.014
Kastemter screeair.es
to«'a
Potei
naso
145
135
168
15.4
8.28
20.5
492
I
itially
fdous Cor.sti
31.6
2*. 4
36.6
3.15
1.8
4.45
107
fluresiws
1.04
0.97
1.21
0.11
0.060
0.15
3.54
ttCIM
0.0073
0.00«*
0.0064
0.00077
0.00041
0.0010
0.025
Sourcei SCS Cnqineers
-------
TABLE 25
TOTAL PROCESS MID POTENTIALLY HMABDOUS HASTE ANTICIPATED TO
GENERATED IN 1983 BY SBBBPSKIH TAMMIES
(metric tens per year, net and dry basis)
10
EVA
PAIKMllK)
I
IZ
III
IV « VI
•V 6 VII
TOTAL
=====
itatcU)
.«E.:III
"A
«V.MJ
PA
fi.rx
fcl.YS. IA
=- - - —
Total
Process
Solid
Waste
Mot
1090
1010
1260
11«
62.1
154
3690
-
Orx
427
J93
495
49.6
24.4
60. 5
14 SO
- .
Total
Potentially
Haiardous
Waste*
Hot
8BO
819
1020
91.9
SO. 4
115
2990
1
Dry
26S
247
107
21.1
IS. 2
37. 5
900
Chroma flashings
TOUl
Potentially
Wet
555
S16
60
S9.2
31.8
70.6
1800
.— —
Drg
139
129
161
14.8
7.94
19.7
471
Chromium
2.22
2.06
2.S7
0.24
0.11
0.11
7. S3
Unfinished leather trianines
Total
Potentially
Net
78. S
73.1
91.1
8.38
4.49
11.1
267
Dry
64.6
60.1
74.9
6.89
1.70
9. IS
219
Chromium
0.29
0.27
0.14
0.011
0.017
0.042
1.00
Coaper
0.022
0.021
0.026
0.0014
0.0011
0.07S
Lead
0.011
0.010
0.012
0.0012
0.0006
0.017
'— - —
EPA
P«>qlon<3
I
11
III
IV • VI
V 4 VI
TOTAL
StatMri}
4R.NH
'.A
r;y.sj
PA
FL.TI
NI.1H.I A
Buffinq dust
T'«ta 1
latent tally
llizjr>un
H>-r.
t'i.1
28.0
14.9
1.21
1.72
4.2C
ioa
Oa
27.2
2S.1
II.?
2.90
l.SS
1.85
92.3
rhrociimn
O.S1
0.49
0.61
0.056
0.010
0.07S
1.79
Constituents
toad
0.019
0.017
0.022
0.0020
0.0011
9.0026
O.M3
Coi*»*r
0.029
0.027
0.014
0.0011
0.0017
0.0042
C.0999
(ine
0.00*4
0.0079
0.0098
>. 04090
1.00048
0.0012
0.0287
Nastewater screenings
Total
Potentially
Hazardous Constituents
Wet
106
99.0
121
11.1
«.09
15.1
Ml
Drg
21. S
21.9
27.2
2. SI
1.14
1.11
79.8
Chromiua
0.76
0.71
0.89
0.081
0.044
0.11
2.6
Cooper
O.OOS1
0.0049
0.0061
(.09056
». 00010
O.OOOS
0.018
Mastovater sludac
Total
Potentially
Hatardoaa Constituent*
Net
110
102
128
11.7
«.l
IS. 6
174
OTJL
11.0
10.2
12. •
1.17
0.61
1.S6
17.4
Chromiup
0.10
0.28
0.1S
0.032
0.017
0.042
1.01
Coppor
0.0:i
O.OCO
0.025
0.00:i
o.ooi:
0.0:30
0.072
Lead
0.0012
O.OOiO
0.0037
0.0003S
0.00019
0.00046
0.011
Sourcei SCS bi7iae*rs
-------
addition, the tables indicate that the total quantity of
potentially hazardous solid waste is anticipated to decrease
by 14 percent by 1977, and 30 percent by 1983, primarily
as a result of decreasing production.
3.6 Split Tannery
3.6.1 Plant Operations. Split tanneries purchase
splits or blue drops from complete chrome tanneries and
further process them into suede leather.
The production process of a typical split tannery is
summarized in Figure 8 and described below. Blue drops
are received at the split tannery wrapped in plastic to
insure that they do not dry out. The splits are trimmed to
remove portions which are too thin to process and then
sorted by thickness. The splits are then re-split to
obtain a uniform thickness, and subsequently shaved to obtain
the exact thickness desired. The -splits are then retanned,
colored, and fatliquored in a manner similar to that used
to produce chrome tanned grain leather. Following fatliquoring,
the splits are pasted on- large, plates or stretched on metal
frames and then dried in an oven. The- resulting suede
leather is buffed to improve the appearance and obtain a
uniform nap. After trimming off ragged edges, the splits
are ready for packaging and shipment to the customer. A
typical split tannery processed 400,000 equivalent hides in
1974.2
Figure 8 also shows the basic production operations
performed, the types and quantities of raw materials and
products involved, and the types and quantities of waste
products.
3.6.2 Potentially Hazardous Solid Haste. As indicated
£
en
in Figure 8, several kinds of solid waste is generated.
The potentially hazardous wastestreams are discussed below.
Trimmings, 'Splits, and Shavings. The initial trimming,
resplitting, and shaving operations generate a total of
8,200 (wet)/3,700 (dry) kg of solid waste per 1000 equivalent
hides processed at a typical split tannery, which on a
nationwide basis amounts to 29,100 (wet)/13,100 (dry) metric
tons per year of which 14,300 (wet)/6,460 (dry) is sold as
a by-product. Samples-were collected from the splitting
machines, shaving machines, and trimming department at six
tanneries. Analysis of these samples indicated an average
chromium concentration of 9,600 (wet)/22,300 (dry) ng/lngt
with a range of 10,000 to 28,000 mg/kg on-a dry weight basis.
94
-------
FIGURE 8
PROCESS PLOW DIAGRAM
TYPICAL SPLIT TANNERY
(All units are kg/1000 equivalent hides on a drv weight basis
except solid wastes which are given on a wet/dry basis)
MATERIALS APPEO
BLUE SPLITS
(6000)
DYES (350) I
RETAN 6 FATLIOUOR V_—••
MATERIALS (900) f
MISC. (300)J
r-A-,
iTRIMl TR!»
ISDRTl
[SPLIT] SPt,
1 SHAVE SHAV
1
RETAN
COLOR WAS1
FATLIQUOR
f ORY I
IBUFF G
TRIM 1
EOE LEATHER
(2500)
4 g
(8200/3700)
TS ,
t\nqs j Mtsr
PROCESS
(22S/200)
'EMATER JSCREENINC] SCREENINGS
" 1 (22/S)
WASTEWATER
TO SEWER
(SOLIDS 1OOO)
UFFING OUST (200/1901
RIM (?30y?0(J
J
1
1
1
1
1
J
1
1
1
1
J
T,
"•1
1
1
1
1
1
PROCESS SOLID WASTE
TO SANITARY LANDFILL
IS.860/4.290)
95
-------
Unfinished Leather Trim. Following buffing and before
packaging for shipment, suede leather is normally trimmed
to remove ragged edges. A typical split tannery generates
230 (wet)/200 (dry) kg of leather trim per 1000 equivalent
hides processed, which on a national basis amounts to
810 (wet)/715 (dry) metric tons per year. Samples were
collected from fiber drums or self-dumping hoppers in the
trimming departments of seven tanneries. Analysis of these
samples indicated the presence of the following hazardous
constituents:
Avg. concentration Concentration range
(mgAg) (mg/kg)
Constituent Wet Dry Dry
Chromium 19,000 21,000 7,600 - 45,000
Lead 250 280 120 - 460
Buffing Dust. Mechanical sanding of suede leather to
remove surface imperfections and to produce a uniform nap
generates fine particles of leather which must be disposed
of as solid waste. A typical split tannery produces
200 (wet)/ISO (dry) kg of buffing dust per 1000 equivalent
hides processed, which on a national basis amounts to
715 (wet)/639 (dry) metric tons per year. Samples were taken
from the buffing dust collection devices at seven split
tanneries. Analysis of these samples indicated the presence
of hazardous constituents as follows:
Avg. concentration Concentration range
(mg/kg) (mg/kg)
Constituent Wet Dry Dry
Chromium 20,000 22r000 1,200 - 60,000
Lead 71 77 44 - 120
Wastewater Screenings. Most split tanneries screen
their wastewater before discharge, and a typical split tannery
generates 22 (wet)/5 (dry) kg of screenings per 1000
equivalent hides processed, which on a national basis amounts
to 78 (wet)/I8 (dry) metric tons per year. Samples were
collected from the wastewater screens at seven tanneries.
The screenings primarily consist of relatively small pieces
of leather which have been torn off'the hides during
processing. Analysis of these samples indicated the presence
of hazardous constituents as follows:
96
-------
Avg. concentration Concentration range
(rag/kg) (ngAg)
Constituent Wet Dry Dry
Chromium 970 4,200 5 - 14,000
Lead 40 175 .43 - 190
3.6.3 Non-Hazardous Solid Waste. Miscellaneous process
solid waste is generated at a rate of 225 (wet)/200 (dry)
kg per 1000 equivalent hides processed, which on a national
basis amounts to 700 (wet)/650 (dry) metric tons per year.
This waste is composed of fiber drums, paper bags, wooden
pallets on which the splits are received, and general plant
floor sweepings, and they do not contain constituents at
potentially hazardous concentrations.
3.6.4 Factors Affecting Future Solid Waste Generation.
Air Pollution Control. Air pollution control devices are
utilized to collect the leather dust which is generated by
buffing. Buffing dust is currently being effectively
collected at a majority of split tanneries. Installation
of adequate and effective collection devices at tanneries
not currently utilizing effective collection systems, and
retrofit installations of more efficient collection systems
which may be required by air pollution control regulations
in certain areas, will not increase the quantity of buffing
dust destined for land disposal by 1977, but will result in
a 10 percent increase by 1983."
Water Pollution Control. The vast majority of split
tanneries discharge their wastewater to municipal sewer
systems with no treatment other than screening. Since the
suspended solids content of the wastewater from a split
tannery is relatively low, it is anticipated that split
tanneries will not find it cost-effective to install
pretreatment facilities. As a result, it is anticipated
that screening will continue to be the predominate type
of wastewater treatment in 1977 and 1983.
Industry Trends. Since the raw material utilized by the
split tanning portion of the leather tanning- industry-is
produced by complete chrome tanneries and retan/finishers,
it is anticipated that production from split tanneries will
follow the growth rate of the sum of the retan/finish and
complete chrome tannery operations. Thus, it is assumed
that the growth rate for split tannery production will be
2.6 percent per year through 1983.2
97
-------
3.6.5 Typical Plant Waste Summary. The current (1974)
and projected (1977 and 1983) generation factors for process
solid waste and the various types and quantities of potentially
hazardous solid waste generated by a typical split tannery
are summarized in Table 26. As the table indicates, the
generation factors for a typical split tannery are not expected
to change appreciably in the future.
3.6.6 EPA Region and National Waste Summary. Table
27 presents the total quantity of process solid waste and
the types and quantities of hazardous constituents, currently
(1974) generated by split tanneries. Quantities projected
for 1977 and 1983 are presented in Tables 28 and 29,
respectively. As indicated by the tables, the vast majority
of total process and potentially hazardous solid waste generated
by split tanneries is Region I. This is in large part due
to the fact that trimmings, splits, and shavings comprise
the vast majority of both total process and potentially
hazardous solid waste, and this type of waste is currently
sold as a by-product in Region V; however, there is no
market for these wastes in Region I.
3.7 Leather Finishers
3.7.1 Plant Operations. Tanneries in this category
normally function on a contract basis. Thus, finishers receive
unfinished leather from a customer, apply a finish to it,
and then return it to the customer, charging a fee for the
service. Finishes are normally applied either by hand or
in mechanical spray booths and may consist of either water
or solvent base preparations. In addition, the leather
is sometimes buffed to remove imperfections in the grain
surface or improve the nap of the flesh side. A typical
leather finisher processed 225,000 equivalent hides in 1974.
Figure 9 summarizes the basic production operations performed,
the types and quantities of raw materials and products
involved, and the types and quantities of'waste products.
3.7.2 Potentially Hazardous Solid Waste. As indicated
in Figure 9, three kinds of solid waste is generated. The
two potentially hazardous wastestreams are discussed below.
The data presented is based upon information collected during
visits to three contract finishers and 22 complete chrome
tanneries. The information from complete chrome tanneries
is included here because the finishing operations performed
in complete chrome tanneries and by contract finishers are
essentially the same. However, contractor finishers do not
have screens or other treatment works.
98
-------
TABLE 26
WASTE GENERATION FACTORS FOR A TYPICAL SPLIT TANNERY
(All units are kg per 1000 equivalent hides)
1974 I 1977*
Waste Type
Total Process Solid Waste
Total Potentially Hazardous
Solid Waste
Trimmings & Shavings
Unfinished Leather
Trial
Buffing Dust
Wastewater
Screenings
Total
Cr
Total
Cr
Pb
Total
Cr
Pb
Total
Cr
Pb
Wet
8,880
8,650
8,200
230
200
22
Dry
4,290
4,000
3,700
78.7
200
4.37
0.058
180
4.0
0.014
5
0.021
0.009
1983
Wet
8,900
8,670
8,200
230
220
22
Dry
4,310
4,110
3,700
78.7
200
4.37
0.058.
200
4.4
0.015
5
0.021
0.009
Sources SCS Engineers
' 80 processing changes are expected between 1974
and 1977 that would change the generation factors. Thus
they are identical.
99
-------
TABLE 27
TOTAL PMCBSS MB POnRZALU HMMD008 BMW
GENERATED IN 1974 BY SPLIT TMMSRXBS
(metric tens per year, vet and dry basis}
EPA
Region (s)
I
V t IX
TOTAL
State (s)
MA.MR
MX.IL.CA
Total
Process
Solid
Waste
wet
14500
2200
1C700
Dry
7100
14 SO
0550
Total
Potentially
Hazardous
waste.-
Wet
14100
1900
14000
DW
6700
1200
7900
Trimmings, splits • shavings*
Total
Potentially
Hasardoue Constituent
Wet
13300
1000
14300
pry.
6000
460
64CO
Chromium
130
10
140
Unfinished leather trlrring*
Potentially
Hazardous
Wet
370
440
010
toy.
330
30S
715
Constituents
Chroaius
7.10
0.41
15.51
Lead
0.10
0.11
O.*l
o
o
BPA
lion(s)
TOTAI,
Statelei
Bnff ia> duct
Potestialiy
330
71S
290
JiS.
439
e.S
-Li.
14.3
0.03
•.OS
Kasteiieter screentncs
Total
Potentially
" ceoetitueate
36
JL
7S
•.030
•.•71
.0014
.0031
tae ref leet that, taia
U aa!4 ia
-------
TABLE 28
TOtAL PltOCBSS AND POTENTIALLY HAZARDOUS HASTE* ANTICIPATED TO
GENERATED IB 1977 BY SKIT TANNERIES
(netrie tens per year, wet and dry basis)
EPA
Reaionfs)
I
V C XX
TOTAL
State lei
MA.NH
HI.XL.CA
Total
Process
Solid;
Haste
Net
19600
2520
uioo
pry.
7610
2470
10100
Total
Potentially
Hazardous
Waste;
S«
1S200
2050
17250
fitt
7270
1300
•570
Trimmings, splits t shavinas*
Total
Potei
Hasai
Met
14400
1110
15500
ttially
Dry.
6500
500
7000
Chromium
138
11
149
Unfinished leather trirwincs
Total
Potentially
Met
400
480
•00
pry.
350
415
7CS
Chroaiua
7.7
9.1
16.8
Leal
0.10
0.12
0.22
EPA
Reaioa(s)
I
v • n
TOTAL
• a
Stated)
NA.HH
VX.tL.CA
B
Buef im doit
Total
Potentially
Batardous Constituents
*££
150
415
7«
u—
S£Z
915
175
690
Quxftipm
7:0
0.1
1S.J
0.025
0.011
0.05C
Nastewater sereeninas
• Total
Potentially •
Batardous Constituents
Vet
39
4«
OS
Or*.
9
10
19
Chroaiun
0.037
0.044
O.OSI
jssai
,0015
0010
.OP33
-------
TABLE 29
TOTAL PROCESS AND POTENTIALLY HAZARDOUS WASTE ANTICIPATED TO BE
GENERATED IN 1983 BY SPLIT TANNERIES
(metric tons per year, wet and dry basis)
EPA
Region (a)
I
V i XX
TOTAL
State (s)
MA.NH
WI.IL.CA
Total
Process
solid
Haste
Wet
1B200
- 2950
aiiso*
Dry.
8800
• 2060
10060
Total
Potentially
aasardous
Waste.
Het
17700
2400
20100
Dry.
8400
1580
990Q
Trimmings, splits t shavings*
Total
Potentially
Hasardous Constituent
Hat
16800
1290
18090
pry.-
7S60
S80
8140
Chxo&ium
160
12
1T2
Unfinished leather triceincs
Total
Potentially:1
Hazardous Constituents
Wet
470
560
10JO
pry.
410
480
890
Chresiun
8.94
10.6
19.5
Lead
0.12
1 0.14
: 0.26
*•*
•State(s)
Total
Potentially
Wastewatev
Potentially
Basardons
Constituents'
I
v *; xx
MA.KH
WX.IL^CA
440
M3
40.
470
6.0"
10.4
0.011
0.017
41.5
59.0
fitt
9.75
11.5
0.041
0.050
.0010
.0021
TOTAL
963
070
17'. 2
0.068
99. J
21.J
0.002
.0039
Sources SC8 Engineers
reflect that this wast* is sold in
-------
FIGURE 9
PROCESS FLOW DIAGRAM
TYPICAL LEATHER FINISHER
(All units are kg/1000 equivalent hides on a dry weight basis
except solid wastes which are given on a wet/dry basis)
MATERIALS ADDED
PIGMENTS
WATER BASE FIN I
SOLVENT BASE
FINISH
MISC.
CRUST LEATHER
(5000)
FINISHED LEATHER
(5000)
BUFFING OUST (11/1O1
FINISHING RESIDUE (150X>
SOLVENTS t VOLATILES
TO AIR U50)
WASTEWATER TO SEWER
SOLIDS (600)
MISC. PROCESS SOLID
WASTES (85/75)
PROCESS SOLID WASTE
TO SANITARY-LANDFILL
(245/130)
103
-------
Buffing Dust. Buffing dust is produced when the dried
and trimmed leather is mechanically sanded to remove surface
imperfections or to improve the nap on the flesh side. A
typical tannery in this category generates 11 (wet)/10 (dry)
kg per 1000 equivalent hides processed, which on a national
basis totals 61 (wet)/56 (dry) metric tons per year. Analysis
of samples taken from the buffing dust collectors at seven
plants showed the presence of the following hazardous
constituents:
Avg. concentration Concentration range
(mg/kg) (mg/kg)
Constituent Wet Dry Dry
Chromium 20,000 22,000 1,200 - 60,000
Lead 71 77 44 - 120
Finishing Residues. Finishing residues are produced as
a result of air pollution control devices on spray booths
and from general cleaning of the finishing equipment. A
typical finisher generates 150 (wet)/45 (dry) kg per 1000
equivalent hides processed, which totals 832 (wet)/250 (dry)
metric tons per year on a national basis. Analysis of samples
taken from the finishing area in nine tanneries indicated
the presence of the following hazardous constituents:
Avg. concentration Concentration range
(mg/kg) (mg/kg)
Constituent Wet Dry Dry
Chromium 525 1,700 <4 - 5,200
Lead 1,100 3,600 <10 - 17,000
Zinc 105 340 (not de- 1,400
tected)
3.7.3 Non-Hazardous Solid Waste. Miscellaneous process
solid waste is generated at a rate of 80 (wet)/74 (dry) kg
per 1000 equivalent hides processed, which amounts to
440 (wet)/420 (dry) metric tons per year on a national basis.
This waste is composed primarily of fiber drums and general
plant floor sweepings, and they do not contain constituents
at potentially hazardous concentrations.
3.7.4 Factors Affecting Future Solid Waste Generation.
Air Pollution Control. Air pollution control devices
are used to remove particulates from the exhaust gases of
spray finishing booths and to collect the buffing dust which
is produced by the buffing machines. A finishing operation
typically has a water-wash system to remove particulates and
aerosols from the finishing spray booth exhaust. It is
104
-------
anticipated that the gradual installation of water-wash
collection systems in the very few tanneries which do not
currently (1974) utilize them, and retrofit installations
of more efficient collection systems which will be required
by air pollution regulations in certain areas, will not
result in an increase in finishing residues by 1977, but
will produce a 5 percent increase by 1983. 23
Finishers with buffing equipment also are equipped with
buffing dust collection devices. Installation of more
effective collection devices are anticipated to be required
by air quality regulations in certain areas; it is anticipated
that this will not result in an increase in finishing
residues in 1977, but will produce a 10 percent increase by
1983?^
Water Pollution Control. Currently (1974) , there is no
solid waste generated as a result of wastewater treatment
by most, finishers. Since the waste load resulting from
finishing operations is relatively low, as compared with
other tanning operations, it is anticipated that pretreatment
of wastewater from finishing plants will not be generally
practiced by 1977 or 1983. As a result, water pollution
control will not affect the quantity of solid waste destined
for land disposal from finishing operations.
Industry Trends. It is projected that there will be
a gradual decline in the production of firms engaged in
finishing only. This decline is based upon two trends in the
industry. The first is the general increased concentration
of both leather producing firms and their customers. Second,
and most important, is a decline in the amount of crust
leather which is being imported for finishing. It is
expected that production from firms engaged in finishing will
decline at the rate of 3 percent per year through 1983. 2
3.7.5 Typj-cal Plant Waste Summary. The current (1974)
and projected (1977 and 1983) generation factors for process
solid waste and the various types and quantities of
hazardous solid waste constituents generated by a typical
leather finishers are summarized in Table 30 . As indicated
in the table, a typical leather finisher currently produces
a relatively small quantity of both process and potentially
hazardous solid waste per 1000 equivalent hides as compared
to other types of tanneries, and this situation is not
anticipated to change significantly by 1983.
3.7.6 EPA Region and National Waste Summary. Table 31
presents the total quantity of process solid waste, and the
types and quantities of potentially hazardous waste, including
their respective hazardous constituents, currently (1974)
generated by leather finishers. Quantities projected for
1977 and 1983 are presented in Tables 32 and 33 , respectively.
105
-------
TABLE 30
WASTE GENERATION FACTORS FOR A TYPICAL LBATBB
Waste
Total Process Solid
Waste
Total Potentially Hasardous
Solid Waste
Buffing' Dust
Finishing Residues
Total
Cr
Pb
Total
Cr
Bn
Pb
1974
Wei
24S
1*1
11
ISO
i 1977* .
Dry
110
ss
10
0.22
0.0008
45
0.07>
0.016
0.17
R FIKI8
HER
_ 1983
wet
2SS
170
12
198
Dry
133
SO
-11
0.24
0.0009
'47
0.083
0.017
0.10
Sourcet SCS Engineers
• No. processing changes are''expected''between 1974
and 1977 that would change the generation factors. Thus
they are identical.
106
-------
TABLE 31
TOTJUPBOCBM MO PORVTXALLY HW
8BM8KATHD.ni 1974 BT LBATBSB
(••trie ton* per year, wot and dry baala)
EPA
Reqion(e)
I
tt
m
V
w « n
TOTAL
State (a}
MB.MA.m
BY
HJ
PA.DB
OH.tL.NS
TN.OC.CA
Total
7roce«>
Solid
«a*ta
net
•28
1S»
201
40. f
-------
TABLE 32
TOTAL HtOCBM
MO PonarrxAUT
1977
(Mtrie tone par yaar, vat and
MTXClMinn TO
SHxiu
dry bails)
EPA
Reqionls)
I
XZ
XXX
• V
XV a XX
< TOTAL
State (a)
MA.MH
m
BJ
M,BI
OH.XXuNX
TH.RC.CA
Total
Proeaai
Solid
Hat
747
J4S
186
37.0
61.3
51.0
1230
397
76.7
98.8
19.6
32.5
27. 0"
652
Total
Potentially
Haiardoua
Haata>
Wat
488
94.4
122
24.2
40.0
J3.3
•02
168
32.5
41.0
0.31
13.0
11.4
276
But f ino duat
Total
Potentially
Baaardoua Conatitaanta .
33.6
6.49
8.36
. 1.6«
, 2.75
2.29
55.2
30.5
5.9
7.6
1.51
2.5
2.08
50.1
0.67
0.13
0.17
0.033
0.055
0.046
. a. 10
Uad
0.0024
0.00046
0.00059
0.00012
0.00020
0.00016
0.0039
Viniahinv raaidooa
Total
Potentially
Hasardoua
Wet
458
08.5
114
22.7
37.5
31.2
. 752
SEX
137
26.6
34.2
6.00
11.3
9.36
225
Constituent*
Chroalua
0.24
0.047
0.060
0.012
0.020
0.016
0.39
line
0.040
0.0093
0.0,12
0.0024
0.0040
0.0033
0.079
0.50
0.097
0.11
0.02S
0.041
0.034
0.13
o
09
Sourcoi SCf
-------
TABLE 33
MB POTBMTIAU.T MIMD008 MUTE ANTICIPATED TO
GENERATED IB 1981 BY LEATHER HBI8RBRS
(metric tens per year* wet and dry baeia)
em
Region (s)
z
zz
zzz
V
ZV * IX
TOTAL
*
State (a)
MA.OT
KY
NJ
PA.DE
Oa.lL.WI
TM.HC.CA
Total
Process
Solid
Haste
Vet
649
125
162
32.1
53.8
44.4
1070
SSL
341
69.7
85.1
1«.9
28.3
23.3
5CO
Total
Potentially
Hazardous
wastes
Hat
433
83.2
108
21.4
35.8
29.6
711
SSL
149
28.6
126
7.39
12.3
10.2
333
Buffing dust
Total
Potentially
Hazardous Constituents
32.1
6.18
• 8.01
1.59
2.66
2.19
92.7
sat
29.1*
5.59
7.25
1.44
2.41
1.99
47.8
Chromium
0.64
0.12
0.16
0.032
0.093
0.044
1.09
Lead
0.0023
0.00044
0.00097
0.00011
0.00019
0.0001C
0.0037
Finishing residues
Total
Potentially
Hasardoua Constituents
Wet
412
79.3
103
20.4
34.2
28.2
(77
Or*
122
23.4
30.3
6.01
18.1
8.32
200
Chromium
0.22
0.042
0.054
0.011
0.018
0.019
0.36
Sine
0.043
0.0083
0.010
0.0021
0.0036
0.0030
0.071
Lead
0.45
0.087
0.11
0.022
0.038
0.031
0.74
o
\o
-------
More them one-half of the total process and potentially
hazardous solid waste generated by leather finishers are
produced in Region I. This situation is not anticipated
to change by 1983, although the quantity of total process
and potentially hazardous solid waste generated by leather
finishers is anticipated to decrease 20 percent by 1983.
3.8 Beamhouse/Tanhouse Facilities
3.8.1 Plant Operations. As shown in Figure 3-7,
beamhouse/tanhouse facilities produce chrome tanned "blue
stock" (hides which have been chrome tanned but not dried
and which are sold to other tanneries for retanning and
finishing). The production processes utilized to produce
blue stock are essentially identical to those used by
complete chrome tanneries to process leather through this
stage.
Brine cured, prefleshed cattlehides are the primary
raw material. After receipt, the hides are soaked in a
water solution in order to return the natural moisture to
the hide fibers. Excess fatty substances are removed
mechanically after which the hides are treated with lime and
sodium sulfide to dissolve the hair. The hides are then
treated with an enzyme to loosen the fiber structure and
subsequently pickled to reduce the pH and to prepare the
fiber for penetration of the tanning materials. The hides
are then tanned with a basic chromic sulfate solution, after
which they are rung to obtain a product with uniform
moisture content. The blue stock is then measured and stacked
on pallets which are wrapped in plastic to prevent loss
of moisture and shipped to the customer. A typical beamhouse/
tanhouse facility processed 300,000 equivalent hides in 1974.'
Figure 10 summarizes the basic production operations
performed, the types and quantities of raw materials and
products involved, and the types and quantities of waste
products resulting from the production process.
3.8.2 Potentially Hazardous Solid Waste. As indicated
in Figure 10, several kinds of solid waste is generated.
The only potentially hazardous wastestream is wastewater
treatment sludges.
Since the waste load of a beamhouse/tanhouse facility
is often more than 20,000 mg/1 total solids, a typical
tannery of this type provides primary clarifications of its
wastewater prior to discharge to municipal sewers. The sludge
which is produced by this process is dewatered and disposed
of as a solid waste. A typical plant generates 10,000'(wet)/
2,400 (dry) kg of dewatered sludge per 1000 equivalent hides
processed, which on a national basis amounts to 21,500 (wet)/
5,570 (dry) metric tons per year. Analysis of a sample taken
from the primary clarifier at one plant indicated the presence
of the following hazardous consitutents:
in
-------
FIGURE 10
PROCESS FLOW DIAGRAM
TYPICAL BEAMHOUSE/TANHOU5B
(All units are kg/1000 equivalent hides on a dry weight basis
except solid wastes which are given on a wet/dry basis)
MATERIALS ADDED
BACTER1CIDES (2
LIME (900
NA S/NAHS (230)
SODA ASH (4SO)
CROHSO*
(NHA)2S04
(1800)
(700)
(4SO)
NA FORMATE <360>
H2S04 (230)
MISC. (250)
CURED CATTLE HIDES
(12.300)
1
) 1 SOAK
) [ LIME
J 1
)1 BATE
1 ^f*9 PICKLE
) V^-"^ TAN
,'[ ^^
\J VR NG
< i
BLUE STOCK
(8900)
WASTEVA
TO SE«E
FLESHINGS ISOOJ ^ SOLD
gj
•ASTEXATER
PRIMARY |
CLARIFICATION 1
/
TER
R
\SLUDGE
(30.000/2.400)
IDEWATERING )-^DEMA
I
I
PROCESS SOLID WASTE
TO SANITARY' LANDFILL
on LAOOON
(f 1.1SO/2.650>
111
-------
Avg. concentration
(mg/Kg)
Constituent Wet Dry
Chromium 5,100 28,000
Lead 25 140
3.8.3 Non-Hazardous Solid Waste. Miscellaneous
process solid waste is generated at a rate of 250 (wet)/
225 (dry) kg per 1000 equivalent hides processed, which
amounts to 526 (wet)/473 (dry) metric tons per year on a
national basis. This waste is composed of fiber drums,
paper bags, strings cut off the blades, and general plant
floor sweepings, and they do not contain constituents at
potentially hazardous concentrations. Fleshings generated
by beamhouse/tanhouse facilities are soldi they were therefore,
not considered as a solid waste.
3.8.4 Factors Affecting Future Solid Waste Generation.
Air Pollution Control. Air pollution control devices
are not currently (1974) used by beamhouse/tanhouse facilities,
since spray finishing and buffing operations are not
performed. It is anticipated that this situation will remain
unchanged through 1977 and 1983.
Water Pollution Control. Primary clarification is
currently (1974) utilized by virtually all beamhouse/tanhouse
facilities to reduce the solids content of their wastewater
prior to discharge to a municipal treatment system, and it
is anticipated that this will continue to be the predominant
level of treatment through 1933. As new beamhouse/tanhouse
facilities are established, it is anticipated that by 1983
an estimated 15 to 20 percent additional waste per 1000
equivalent hides processed will be disposed to the land,
either in the form of sludge from primary (and possibly
secondary) treatment facilities or by evaporation lagoons
or other land disposal means.
information collected during this study indicates that
the quantities of chemicals used to perform specific
operations (i.e., tanning) vary considerably from one plant
to another. This variation is in part a result of successful
efforts at some tanneries to conserve chemicals. It is
anticipated that as the price of chemicals continues to
increase, more tanneries will reduce chemical usage, and
new tanneries will be planned 'so as to use less chemicals.
As a result of reducing chemical usage; the solids
content of the wastewater can be expected to decrease.
Consequently, less sludge will be generated as a result of
primary treatment of wastewater. It is anticipated that by
112
-------
1983, chemical conservation techniques will reduce the
quantity of sludge generated per 1000 equivalent hides
processed by 15 to 20 percent. Overall it is expected
that on a dry weight basis per 1000 equivalent hides processed,
the reduced quantity of sludge generated due to conservation
of chemicals will approximately equal the increased quantity
of waste destined for land disposal due to increased
treatment facility removal efficiencies and land treatment.
Industry Trends. Current industry opinion is that
beamhouse/tanhouse facility production will grow at a rate
of 8 percent per year, as a result of several considerations.'
First, the large beamhouse/tanhouse facilities observed had
more efficient operations than smaller complete chrome
tanneries. Secondly, it is anticipated that many of these
beamhouse/tanhouse facilities will be located close to the
source of the cattlehides (the West and Midwest) in order
to reduce shipping costs. Also, complete chrome tanneries
currently located in cities with increasingly stringent
pretreatment requirements were discussing the feasibility
of moving the beamhouse/tanhouse part of their operations to
other locations, while maintaining the retan and finishing
operations in their current location.
3.8.5 Typical Plant Waste Summary. The current (1974)
and projected (1977 and 1983) generation factors for process
solid waste and the various types of potentially hazardous
solid waste are tabulated below. These factors are in
units of kg per 1000 equivalent hides. No change in these
generation factors is anticipated through 1983.
Wet Dry
Total process solid waste 10,250 2,630
Total potentially hazardous
solid waste—dewatered
primary treatment sludges 10,000 2,400
Chromium 51
Lead 0.25
3.8.6 EPA Region and National Waste Summary. Table 34
presents the total quantity of process solid waste, and the
types and quantities of potentially hazardous waste, including
their respective hazardous constituents, currently (1974)
produced by beamhouse/tanhouse facilities. Quantities
projected for 1977 and 1983 are presented in Tables 35 and
36, respectively. As these tables indicate, the quantity
of process and potentially hazardous solid waste generated
by beamhouse/tanhouse facilities is expected to increase by
26 percent by 1977 and 100 percent by 1983. This increase
113
-------
TABLE 34
TOTAL PROCESS AND POTENTIALLY HAZARDOUS WASTE.
GENERATED IN 1974 BY BEAMHOUSE/TANHOUSB FACILITIES
(metric tons per year, wet and dry basis)
EPA
Region (s)
I, II, VI
ft IX
V ft VIII
TOTAL
'
State (s)
MA.NJ
AS.TX
MN,WI,
CO
Total
Process
Solid
Waste
Wet
4210
6310
11000
21500
ssssssss
Dry.
1090
1630
2850
5570
'.a
Total
Potentially
Hazardous
Waste"
wet
4110
6160
10800.
21100
=========
SEX
986
1480
I 2580
5050
Wastevater sludge
Total
Potentially
•Hasardous Constituents
Wet
4110
6160
10800
.21100
^••^•MMi^^MMH
Dry.
986
1480
2580
5050
SS5S5S8SS
Chromium
21.0
31,4
,
54.9
107
BBBBSBBBBSBSB
Lead
0.10
0.15
0.27
0.5)
SS8SSSS
Sources 8CS Engineers
-------
TABLE 35
TOTAL PROCESS AND POTENTIALLY HAZARDOUS HASTE ANTICIPATED TO BE
GENERATED IN 1977 BY BEAMHOUSE/TANHOUSE FACILITIES
(metric tons per year, wet and dry basis)
EPA
Region (s)
It II. VI
& IX
V & VIII
VII
TOTAL
State (s)
MA,NJ
AZ,TX
MN,WI.
CO
I A, MO
. Total
Process
Solid
Waste
Het
5300
7940
13900
27100
Dry
1370
2050
3590
7010
Total
Potentially
Hazardous
Waster-
Wet
5170
7750
13500
26400
Dry
1240
1860
3250
6350
Wastewater sludge
Total
Potentially
Hazardous Constituents
Wet
5170
7750
13500
26400
Dry
1240
1860
3250 •
6350
Chromium
26.3
39.4
68.9
135
Lead
0.13
0.19
0.34
0.66
U1
Sourcei SCS Engineers
-------
TABLE 36
TOTAL PROCESS AWD POTENTIALLY HAZARDOUS WASTE ANTICIPATED TO BE
RATED IN 1983 BT BBMUfODSE/TAHHOUSE 7ACXLXTIBS
(metric tons per year, wet and dry basis)
EPA
Region (s)
X.IX.VX
• XX
V t VXXX
VII
TOTAL
State (0)
MA,RJ
AB,TX
m*wi,
00
XA.MO
Total
Process
Solid
Haste
Met
•410
11600
22000
43000
Dry.
2170
3260
STOO
11100
Total
Potentially
Baia7^Mu •
Waste
Hat
8200
12300
21SOO
42000
fist
1970
2»SO
9160
10100
Haatevater sludae.
Total
Potentially
Bazardous ' ' Constitv
Hit
6200
12300
21SOO
42000
fist
1970
29SO
S160
10100
Chroaiom
41.9
62.6
110
21S
ents
Mad
0.21
0.31
O.S4
1.06
-------
is anticipated primarily as a result of increased production
by bearohouse/tanhouse facilities, and is expected to occur
in Western and Midwestern states.
3.9 Retan/Finishers
3.9.1 Plant Operations. The retan/finish portion of
industry includes those plants which purchase blue stock from
beamhouse/tanhouse facilities and process it into finished
leather. The basic processes utilized, as shown in Figure 11
are essentially identical to those used in the later stages
of the production process at a complete chrome tannery.
A retan/finisher receives blue stock on pallets wrapped
in plastic. After unpacking, it is normally sorted by
thickness and then split to a uniform thickness. Next, it
is shaved to obtain the exact thickness desired and retanned
with chrome, vegetable, and/or synthetic tanning materials.
Following retanning, the hides are colored and fatliguored.
The hides are stretched on a metal frame, pasted on large
plates, or hung on racks and dried. The resulting leather
is trimmed, physically conditioned to soften the leather,
and buffed to smooth the grain surface or the flesh side.
At this point, the leather is ready for finishing with a
water or solvent base preparation which is used to improve
wear and appearance. Following finishing, the leather is
trimmed, measured, and then packaged for shipment. A typical
retan/finisher processed 675,000 equivalent hides in 1974.
Figure 11 also indicates the basic production operations
performed, the types and quantities of raw materials and
products involved, and the types and quantities of waste
products resulting from the production process.
3.9.2 Potentially Hazardous Solid Waste. As indicated
in Figure 11,eight kinds of solid waste is generated by
retan/finishers. The potentially hazardous, wastestreams are
discussed below.
Blue Trimmings and Shavings. Blue trimmings and shavings
are generated when tanned hides are split and shaved to obtain
leather of a uniform thickness. A typical retan/finisher
generated 325 (wet)/I40 (dry) kg of trimmings per 1000 equivalent
hides processed and 930 (wet)/400 (dry) kg of shavings per
1000 equivalent hides processed, which on a national basis
totals 3,100 (wet)/I,300 (dry) metric tons per year. Samples
were collected from the shavings machines and fiber drums
in the trimming departments of six plants. Analysis of
these samples indicated that these wastes have an average
chromium concentration of 9,600 (wet)/22,300 (dry) mg/kg,
with a range of 10,000 to 28,000 mg/kg of a dry weight basis.
117
-------
FIGURE 11
FLOW DIAGRAM
TTMCA1. RETAN/FimSHBft
(All units are kg/1000 equivalent hides on a dry weight basis
' except solid wastes which are given on a wet/dry' Basis)
BLUE STOCK
IS900)
MATERIALS AOOEP
SPLIT
SHAVE
TRIM O*SSt4at
SHAVINGS (41OX*OOI
AS av-pmnuer
J
SVNTANS
FATLIQUORS
DYES » PIGMENTS
MISC.
WATFR t SOLVENT
BASE FINISHES '
MISC.
«730^
(SOOli^g
ISOOJf^
csobj
RET AN
COLOR
FATLIOUOR
JH
DRY •
TRIM
CONDITION
•BUFF
FINISH
TRIM '
ATILES TO
I«9O»
4/IOO>
FINISHING RESIDUES I I SO/451
FINISHED LEATHER
ISOOO)
SHI-:n LEATMCR TRIM
( 220/200 1
MISC. PROCESS
.ID WASTES ~
(2SO/22S)
SCRECMINfiS CAOX1OI
^
WASTEWATCR
. TO SEWER
(SOLIOS-ISOO)
PROCESS SOLID VASTC
TO SANITARY LANDFILL
f2086/1130)
118
-------
Unfinished Leather Trim. Following drying and before
finishing, the sides of leather are normally trimmed to
remove ragged edges which would otherwise interfere with
the finishing process. The average rate of generation of
this material is 114 (wet)/100 (dry) kg por 1000 equivalent.
hides, which on a national basis totals 380 (wet)/246 (dry)
metric tons per year. Analysis of samples collected from
the trimming departments of seven plants indicated the
presence of the following hazardous constituents:
Avg. concentration Concentration range
(mg/kg) (mg/kg)
Constituent Wet Dry Dry
Chromium 15,000 17,000 3.600 - 42,000
Lead 110 130 3 - 530
Buffing Dust. Buffing dust is produced when the dried
and trimmed leather is mechanically sanded to remove surface
imperfections and/or to improve the nap of the fleshed side
of the leather. A typical tannery in this category generates
27 (wet)/25 (dry) kg per 1000 equivalent hides, which on a
national basis totals 66 (wet)/61 (dry) metric tons per year.
Analysis of samples taken from the buffing dust collectors
at seven plants indicated the presence of the following
hazardous constituents:
Avg. concentration Concentration range
(mg/kg) (mgAg)
Constituent Wet Dry Dry
Chromium 20,000 22,000 1,200 - 60,000
Lead 71 77 44 - 120
Finished Leather Trim. The final operation performed
before packaging the finished leather for shipment is
trimming. A typical plant produces 220 (wet)/220 (dry) kg
per 1000 equivalent hides processed, which on a national
basis totals 541 (wet)/492 (dry) metric tons per year.
Analysis of samples collected from the trimming and shipping
departments of three plants indicated the presence of the
following hazardous constituents:
Avg. concentration Concentration range
(mgAg) (mgAg)
Constituent Wet Dry Dry
Chromium 19,100 21,200 7,600 - 45,000
Lead 250 280 120 - 460
119
-------
Finishing Residues. Finishing residues are produced as
a result of air pollution control devices on spray finishing
booths and from general cleaning of the finishing equipment.
A typical retan/finisher generates 150 (wet)/45 (dry) kg
per 1000 equivalent hides processed, which totals 369 (wet)/
111 (dry) metric tons per year on a national basis. Analysis
of samples-taken from the finishing area in nine plants
indicated the presence of the following hasardous constituents!
Avg. concentration Concentration range
(mg/kg) (mg/kg)
Constituent - Wet Dry Dry
Chromium 525 1,700 <4 - 5,'200
Lead . 1,100 3,600 <10 - 17,000
Xinc 105 340 (Hot de- 1,400
tected)
Wastewater Screenings. Retail/finishers normally screen
their wastewater. A typical plant, produces 40 (wet)/10 (dry)
kg per 1000 equivalent hides processed, which on a national
basis totals 98 (wet)/25 (dry) metric tons per year.
Analysis of samples collected from the wastewater screens
in seven plants Indicated the presence of the following
hazardous constituents! •
Avg. concentration. Concentration range
(mgAg) (mgAg)
Constituent Wet ~ Dry Dry
Chromium. 965 4,200 5 - 14,000
Lead' 40 176 43- 190
3.9.3 Non-Hazardous solid Waste.- Miscellaneous
process1 solid waste is generated at a rate of 250 (wet)/
225 (dry) kg per 1000 equivalent hides .processed, which
amounts to 525 (wet)/470 (dry) metric tons per year on a
national basis. This waste is composed of fiber drums,
paper bags, and general floor, .sweepings, and they do not
contain constituents at- potentially hasardous concentrations.
3.9.4 Factors Affecting Future Solid Haste Generation.
Air Pollution Control. Air pollution control devices -
are used to remove participates produced- by .the spray
finishing process and to. collect buffing dust; - The retan/
finisher typically has, a water-wash system^ to remove
particulates from the finishing spray booth, exhaust. The
particulates removed are currently .a relatively minor source
of solid waste. It is anticipated that gradual installation
120
-------
of water-wash collection systems in the few tanneries which
do not currently (1974) utilize them, and retrofit installation
of more efficient collection systems which will be required
by air pollution control regulations in certain areas, will
not result in a significant increase in finishing residues
by 1977, but will produce a 5 percent increase by 1983.23
Buffing dust is currently being effectively collected
at a majority of retan/finishers. Installation of adequate
and effective collection devices at tanneries not currently
utilizing effective collection systems will not increase
the quantity of buffing dust destined for land disposal
by 1977, but will result in a 10 percent increase by 1983. 23
Water Pollution Control. Screenings are the only type
of potentially hazardous solid waste currently generated
by retan/finishers as a result of wastewater treatment. Since
Federal effluent limitation guidelines for tanneries are
currently under litigation, no changes in solid waste generation
as a result of wastewater treatment are expected by 1977.
However, it is anticipated that by 1983, 25 percent of the
retan/finishers will utilize primary pretreatment to remove
wastewater solids. It is estimated that this will result
in 1000 (wet)/100 (dry) kg of sludge per 1000 equivalent
hides processed, which on a national basis will total 810 (wet)/
81 (dry) metric tons per year.
Industry Trends. The growth in the retan/finish
portion of the leather industry will basically parallel
the growth in the beamhouse/tanhouse portion of the industry,
except that a portion of the blue stock produced by the
beamhouse/tanhouse facilities will be exported. As a result,
the growth in the retan/finisher category is projected at
5 percent per year through 1983, compared to the 8 percent
per year projected increased for beamhouse/tanhouse facilities.2
3.9.5 Typical Plant Waste Summary. The current (1974)
and projected (1977 and 1983) generation factors for total
process solid waste and the various types and quantities
of potentially hazardous solid waste generated by a typical
retan/finisher are summarized in Table 37 . The increase
in potentially hazardous solid waste anticipated for 1983 is
primarily the result of the installation of sewer sumps by
a typical retan/finisher to renove wastewater solids.
3.9.6 EPA Region and National Waste Summary. Table 38
presents the total quantity of process solid waste and the
types and quantities of potentially hazardous waste, including
their respective hazardous constituents, currently (1974)
produced by retan/finishers. Quantities projected for 1977
and 1983 are presented in Tables 39 and 40, respectively.
121
-------
TABLE 37
MASTS GBNERATXOM FACTORS. FOR'A TYPICAL RtTAM/FIWIBWtR
units an kg per 1000 equivalent
v.
Waste Type ~ •
Total Process Solid W
Total .Potentially Basi
Solid Waste
•7
Trimiiigs t 'Shavings
Unfinished Leather
Trim
Buffing Dust
Finished Leather
Trim
Finishing Residues
Wastewater
Screenings
Wastewater Sludge',,
(from sewer sump)
iste
irdous '
Total
Cr
Total
Cr
Pb
Total!
Cr
Pb
Total
Cr.
Pb' .
Total
Cr
Pb
In
Total
Cr
Pb
Total
Cr
S
1974 4 1977V'
2,0*0 1,150
1,010 tao
1,3«0 540
— 12.1
114 100
— I.ft71
0.31
a- as
— 0.54
— 0.0010
220 200
— 4.2
— 0.055
ISO 45
•-• 0.079
— r 0.17
— O.OM
40 . 10
— 0.039
— O.OOlC
::: :E
1903
2,120 1.100
2.070 950
1.240 540
114 100
— 1.71
— 0.31
30 ao
— O.S9
— 0.002
aao ado
— 4.2
— O.OSS
ISO 47
— 0.00
— 0.10
— 0.017'
40 10
— 0.039
— 0.0010
is* ,*a
— 0.05
••*•» Q« OW
Sourcei SCS Engineers
• -No processing: .changes are-expected between 1974
and 1977 that would change the generation factors.
they are identical.
122
-------
TABLE 38
TOTAL PROCESS M0> POTB8T1ALLY RAMMOOS WASTF
GENERATED IB 1974 BY RBTAN/FINISHERS
(metric tons par year, «%t and dry basis)
BPA
Region (s)
I
IX
III
IV.VHX
TOTAL
State ( s)
MA.NH.ME
NY
NJ
PA
TO.WI.CA
Total
Process
Solid
Waste
wet
2320
1360
185
309
892
5070
Dry.
1290
756
103
172
496
2820
Total
Potentially
Hazardous
Wastes
Wet
2040
1190
163
272
784
4450
Dry.
1040
€07
82.8
138
398
2270
Trim and shavings
Total
Potentially
Basardous Constituent
Met
1420
832
113
189
546
3100
Dry.
608
356
48.6
81.0
234
1330
Chromium
13.6
7.99
1.09
1.82
5.24
29.7
Unfinished leather trimming*
Total
Potentially
Hazardous Constituents
Net
128
75.2
10.3
17.1
49.4
380
pry.
113
66
9
15
43
246
ChroBJuia
1.93
1.13
0.15
0.26
0.74
4.21
Lead
0.14
0.083
0.011
0.019
0.05;
0.31
EPA
Reg ion (s)
I
XX
ttt
xv.vtix
TOTAL
State (s)
MA,NH,MB
NY
HJ
PA
TN.HX.CA
riaishina residues
Total
Potentially
Basardous Constituents
vet
169
•9
13. $
.22.5
65. 0
36*
S0.7
26.7
4.05
6.75
19.5
111
Chroaiua
0.089
0.032
8.0071
0.012
0.034
0.19
Lead
0.19
0.11
0.01S
0.025
0.071
0.41
line '
0.018
0.010
0.0014
0.0024
0.0068
0.019
tfastewater. screenings
Total
Potentially
Hazardous Constitu
Met
45
26.4
3.6
6.0
17.3
98.3
sat
11.3
6.60
.90
l.SO
4.33
24.4
Chroaiun
0.044
0.026
0.0035
0.0058
0.017
0.096
ents
Lead
0.0018
0.0011
0.00014
0.00024
0.00069
0.00)9
-------
TABLE 38
(Continued)
5.
EPA
taafcmd)
I
SZ
III
XV.Vim
font
Stated)
;
NA.HR.NI
m
,93
>A
n.m.cft: ..
.
Buff lM dust
Vofca.
Potw
«*t
30.4
17. •
;a.43
4.05
'11.7
4<.a
itially .
. 28.2
14. S
2.2S
: I-.TS
' 10.1
u.s
•Chromium
0.41
0.34
0.04*
' O.OU
0.23
1.33
tead
0.0020
,0.0012
1.00014
1.00027
1.0007? .
0.0044
riniahca laattor trim
fatal
Potaatially
SSI
240
14S
19. •
32
ts.s
Ml
&EX
229
' 132
10'. 0
30.0
04.4
4ta
.^M^- M
CBraBlua
4.73
2.77
0.30
0.41
1.12
1 10.0
toad
0.0(2'
. 0.034
0.0090
0.0003
0.024*
0.1M
-------
TABLE 39
TOTAL PROCESS AID POTENTIALLY HAZARDOUS HASTE. ANTICIPATED TO
GENERATED IN 1977 BY RBTAN/PINISBERS
laetrle ten* per year, wet and dry basis)
CJ
in
EPA
Region (a)
X
XX
XXI
xv.vtxx
TOTAL
State (s)
MA,NH,MB
MX
8J
PA
TN.HX.CA
Total
Process
Solid
Haste
Net
2680
1570
214
358
1030
5850
1490
875
119
199
574
3260
Total
Potentially
Hazardous
Waste'
Net
2350
1380
188
315
907
5140
Or*
1200
'703
95.7
160
461
2620
Trim and shavinas
Total
Potentially
Hazardous Constituent
Hat.
1640
963
131
219
631
3580
prjt
702
413
56.2
94.0
271
1540
Chromium
15.7
9.24
1.26
2.11
6.06
34.4
Unfinished leather trimmings
Total
Potentially
Hazardous Constituents
Met
148
87.1
11.9
19.8
57.1
324
Dig .
130
76.4
10.4
17.4
50.1
284
Chromium
2.22
1.31
0.178
0.298
0.857
4.86
Lead
0.163
0.096
0.013
0.022
0.063
0.36
EPA
Reaionfsl
X
It
XXX
XV.V.XJC
TOTAL
•IBBBHBW^S^H^^SB^SBB
State (•)
NA.HH,MB
MT
Kf
PA
TS.W.CA
^^•^•••••^•l^MWMMMHMMMH^SSSS^SlSMieMSBeHSBiaM^^H^H^H^MMBVMHM^SM^S^
rinishiiM residues
Vote
Pott
Basa
Wet
195
115
1S.C
26.1
75.2
427
ntially
rdous Constituents
SB
59
14.4
4.66
•
7.83
22.5
128
Chromium
0.10
0.060 •
0.0082
0.014
0.040
0.22
Lead
0.2
0.13
0.017
0.029
0.083
8.46
ifee
0.021
0.012
0.0016
0.0026
0.0075
0.045
Maatewator. screeniiras
xotai
Potentially
Hazardous Constituents
Jet
52.0
30.6
4.16
6.96
20.0
114
fist
13.0
7.64
1.04
1.74
S.Ol
26.4
Chromium
0.0 JO
0.030
0.0040
0.0067
0.019
0.11
Lead
0.0021
0.0012
0.00017
0.00028
0.00080
0.0046
-------
TABLE 39
(Continued)
IPX
Reqion(t)
i
»
i» ,
< IV.Vtix
' *°W
State (a)
I MftfMRf MS
m
w
PA
i • ; ,<
n.vx.ca
j
Bof f iM 4u«t
Total
Potentially .
Baiardous Conttiti
Ha*
35.0
ao.e
Ml
4.70
19.3
7«.«
33. 0
lt.1
2.6
4.3J
1
>11.S
71. «
' fhroniun
0.70
0.41
O.OM
o.o»4
" '0.»7
1.53
imti
!£«
0.0023
0.0014
0.0001*
0.00091
t
' b.oooo*
0.0050
riaished laatter trim
Teta
Pott
Baia
££
206
IM
22.9
30.3.
' 110
02S
I
ntially
rdous
SEZ
260
153
20.0
94.0
100
M»
. phranim
5.44
3.21
1 0.44
| 0.79
2.10
. 11.9..
Ba«
0.072
0.042
0.0057
0.009*.
0.020
L ••*•
-------
TABLE 40
TOTAL PROCESS AHD POTENTIALLY HACARDOOS WASTE., ANTICIPATED TO BE
GENERATED IN 1983 BY RETAN/PINISHBRS
(metric tens per year, wet and dry basis)
EPA
I
II
III
IV.VSIX
TOTAL
State (a)
MA.NH.ME
NY
NJ
PA
TN.WI.CA
Total
Process
Solid
Waste
wet
3910
2290
312
521
1SOO
8530
pry.
2040
1200
163
272
785
4460
Total
Potentially
Hazardous
Wet
3470
2030
277
462
1330
7570
pry.
3470
965
132
219
633
5420
Trim and shavings
Total
.Potentially
Hazardous Constituent
Wet
2210
1290
176
294
849
4820
pry.
946
554
75.6
126
364
2070
Chromium
21.2
12.4
1.69
2.82
8.14
46.3
Unfinished leather tr innings
Total
Potentially
Hazardous
Wet
199
117
15.9
26.6
76.6
435
Dry.
176
103
14.0
23.4
67.5
384
Constituents
Chromiun
3.00
1.76
0.24
0.40
1.15
6.55
Lead
0.22
0.13
0.018
0.029
0.034
0.48
to
EPA
Region (•)
Z
IX
IZI
IV.VtIX
TOTAL
state (•)
MA,NH,MB
NY
HJ
PA
TN.HZ.CA
Buffing dust
Total
Potentially .
Hazardous Constituents
wet
50.7
29.7
4.05
6.75
19.5
111
pry.
46.2
27.1
3.69
6.15
17.8
101
Chromium
1.00
0.59
0.080
0.13
0.39
2.19
Lead
0.00332
0.0020
0.00027
0.00044
0.0013
0.0073
Finished leather trim
Total
Potentially
Hazardous Constituents
Wet
385
226
30.8
51.3
148
841
Dry. f
350
205
28.0
46.7
135
765
Chromiun
7.32
4.29
0.59
0.98
2.81
16.0
Lead
0.097
0.057
0.0077
0.013
0.037
0.21
-------
TABLE 40
EPA' _ ,
Region Cs)
X
XI
1X1
XV,V*IJ{
TOTAL
•. statoJklL
MA0HH,M2.
NY
US
PA , ;
"-"TO/WXjCA '
, " Finishing .xesldwoa
,. *etal--
Petontialiy
Hazardous w,uu& vA<*u<;j4u.a>
. We.t -
27li
159
21*7
36.2
104
591
Pry
81.3,
47. S
S.4S
ie.8
31.2
177
;'.. ChroaiUB
-0.14 :
0.084
O.Olt
S/^l§ •
«««8S5
,. . <*°n ..
• jssa*
•0.30-
0.175
;' 9.024. ...
•&. 0.40' ~
0.12 :
o.«s
3iHO
• 0.29
0.17
.0.623
"e.@w :
till'"
'-:*".«,,
Wastewater. ssrconinga
ffotal v
Potentially
"Jfazardous ' -Constituents •
Wet
74.3
43.6
S.,9'3
9.9'
28.6
163
2St
ia.i
.U.2
. 1*»3
-2.«S
7.3«
41.7
ehrgmiusi
:e»e73;
0.042
e.eoss.
ie.ei®'
Q.023
aui
Load
0.0029
o.@ei7
@.8G923
O.SCOSS
0.6011
o.eess
ISP*
rRe^|ohj»]
X
II
' III
my«iit:.
TOTAL
StatoCs)
HA.KB«MI
H¥
KJ
PA
TIL^JUCA
: - ' «*»»t«wat«r ilufl^«
TOtki • * ' "'
Potentially .
Bazairdous Con*titu«nt*
Met
^^*^^
282
16$
22. S
37.5
108
615
SOt
26.2
16.5
2.2S
3.7S
19. S
61,5
Chrmiua
8,76
0.45
0.061
0.10
0.29
, l.M
Cops«r
0,034
0.032
0.0043
0.0072
0.020
°-,H ,
2*£&
0.0071
0.0042
O.OOOS7
0.9009S
0.0027
^J0.016
«oare*t SCS
-------
As the tables indicate, the vast majority of retan/finish
solid waste is, and will continue to be, generated in four
Eastern states. The quantities of waste generated are
anticipated to increase 17 percent by 1977 and 69 percent
by 1983.
3.10 State and EPA Regional and National Waste Quantities
The quantities of total process and potentially hazardous
waste destined for land disposal are listed for 1974, 1977,
and 1983 in Tables 41 through 43 , respectively. All
categories of tanneries are grouped together, and state, EPA
Region, and national quantities are shown. The data
presented is based on the quantity of solid waste generated
at the 41 tanneries visited (in units of kg per equivalent
hide processed); the composition of the waste generated, as
determined by laboratory analysis (in rog per kg of waste);
and industry production data (in units of equivalent hides).
Data for states with less than three tanneries has been
combined in order to protect the confidentiality of production
information.
As shown in Table 41 , more tannery process solid waste
and potentially hazardous solid waste is generated in
Massachusetts than in any other state, followed by Wisconsin
and New York. Similarly, approximately one-half of the
total process and potentially hazardous solid waste generation
occurs in EPA Regions I and V. Minor amounts of solid waste
is generated in EPA Regions VI, VIII, and X. In most states,
the potentially hazardous solid waste generated represents
about 90 to 95 percent of the total process solid waste.
Significant exceptions to this pattern occur in skates such
as Pennsylvania, Georgia, Kentucky, and Virginia, where most
or all of the production occurs in vegetable tanneries.
Tables 42 and 43 show the distribution by state of
total process and potentially hazardous waste generation
projected for 1977 and 1983, respectively. As indicated,
waste generation is projected to increase gradually through
1983 in all states except those with a large proportion of
vegetable tanneries. This trend is anticipated since production
of chrome tanned cattlehides and pigskins is expected to
increase, while vegetable tanned and sheepskin leather
production is expected to decline.
On a dry weight basis, quantities of total process
solid waste will increase 37 percent and potentially hazardous
waste by 51 percent by 1983. Industry-wide production is
estimated to increase 12 percent bv 1983; however, production
for the industry segment generating potentially hazardous
waste (all tanneries with the exception of vegetable '
tanneries) will increase 14 percent.2
129
-------
TABLE 41
TOTAL PROCESS AND POTENTIALLY HAIAMNMS SOLID MAST!
GENERATED BT ALL TYPES OF TANNERIES in 1174
(metric tona per year, wet and dry basis)
Source i 8C8 Engineers, except production Inforaation vhteh is from Tanners* Council oC America
types of tanneries
Note i Totals way not add due to rounding.
Production is based on the sun of all hides pat into proMSsiaf at all
130
-------
TABLE 42
TOTAL PROCESS AND POTENTIALLY HAZARDOUS BOtID WASTE
GENERATED BY ALL TYPES OP TANNERIES IN 1977 {PROJECTED)
(metric tons per year, wet and dry baits)
State (s)
AK.NA
A .I:A
vrr
..GA
(] III
f '
.TX
i .VT
1 t.VA.WV
1
1
.
! !
1
!
' 1
•X
Total
Reeion 1
it
ill
IV
V
VI
V1I1
IX
X
Total
Process
Solid
Haste
Wot
215
14.900
Jl.SOl
717
1.0.4
8.3!
1.34
§.84
.l!
! H
1 .41
1 .M
.' J i
.7!
. 3J
£l ll
~v .^ i
3.' >i
17. il
2.21
I
16. 1
*. !
«'i it
i
i!
1
1
l!
o
0
1
1
II
-r
>o
10
ll
III
>4
ib
iO
III
220.000
60.100
21.61
30.31
18.11
Hfll
10
'0
10
0
908
i1. 580
14.900
1.1BO
pry.
68
4.920
689
232
417
2,750
: 21
l.!iJO
1.140
258
,600
,000
1 ,160
.760
.230
,470
.760
,280
Lilo
505
281
i j29ll
. ,s4iP
n , s'i'o"
69.100
22.450
7.390
7, 520
3,900
17 . 600
258
689
4.920
349
Total
Potentially
Hazardous
Hastes
Hot
220
13.100
i >8
7.440
225
5.7OO
0
768
12.:
DO
65
13.900
0.040
7.050
8,1
1Q. .1
3f',l
10
( 1
JO
17.000
9
749
6.860
5.74O
27 . 500
173.000
56.500
21.4
00
7,750
S. 810
5O.250
768
2.540
13.700
969
SSL
54
4,100
612
180
19
2.240
56
1.380
0
IBB
3,610
40
12,200
2,210
1,820
2.080
3,000
1,020
5.030
1
183
1,780
1,430
7.640
51.000
18.800
6.050
2,OOO
1,4 SO
14,000
188
612
4,100
237
Potentially lUsavdous Constituents
Chromiusi
1.07
82.4
1*1*
3.44
0.33
44. S
1.05
28.
3.8
70.
0.7
ZI
41!'.
36.
43.
ii.
19.
91!.
O.OO4
3.6
34.
ia.
153
1.000
375
111
39. O
2S.4
278
3.87
12.9
82.4
4.68
Sine
0.00040
D.O3O
0.00087
8. 655 5
6.OOO28
O.01B
0.O016
V.OO13
O
0.0OOS2
0.037
0.00OJG
0.1O
0.02O
0.013
0.O01O
O.026
0.018
A Oft*
01. 0002 5
0.O016
0.18
O.016
B. AM
0.50
0.16
0.O0J
0.19
0.V17
0.11
d. 00062
O.OOOB7
0.030
O.0021
tesi
o.ou
0.96
.070
O.OO42
O.50
d.v^/
0.16
0
0.025
O.98
O.012
2.08
0.63
0.46
O.24
0.75
0.36
1..55
0.0027
0.052
0.52
0.44
I ••
11.9
1.01
2..B1
O.60
0.90
3.6O
0.029
O.OBZ
O.9C
O.060
Copper
0.032
1.62
0.58
O.flO
O.OoSn
1.17
0.I^Jl
0.040
0
0.017
2.0J
0.024
2.0V
1.30
0.68
d.vss
l.«B
0.34
2.20
0
0.11
0.V3
0.11
\ Jol
19.6
~2.6»
1.06
0.S2
6.B6
B.O17
0.058
1.72
O.14
Source i SCS Ingii
•otei Totals s«y not add due to rounding.
131
-------
TABLE 43
TOTM, MOCRM MD •OtOfrtAUT
CBHERATEO BY ML TWU OT TMBMMB* » IMJ
(swtrie
Total
Process
Solid
Msste
•oareot 8CS Baginaon
it Totals
to
132
-------
Thus, part of the increased waste quantities can be attributed
to increased production. Much of the remainder of the increase
is due to increased generation of wastewater sludge. Complete
chrome tanneries will generate 68 percent more sludge in 1983
and sludge from beamhouse/tanhouse facilities will increase
100 percent. No other wastestream in these categories is
expected to increase so significantly; most will generate
from 10 to 25 percent more waste by 1983. Some wastestreams
in the retan/finisher category are projected to increase
more than 50 percent; however, their total quantities will
not make as significant an impact as the wastewater treatment
sludges.
133
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SECTION 4.0
TREATMENT AND DISPOSAL TECHNOLOGY
4.1 Introduction
Essentially all solid wastestreams generated by tanneries
using chrome as their tanning medium and those operations
limited to leather finishing were characterized in Section
3.0 as being potentially hazardous. In each instance, the
wastestream was designated as potentially hazardous on the
basis of its heavy metal content. Each of the wastestreams
had one or more of the heavy metals—lead, copper, zinc,
or trivalent chromium in concentrations greater than the
geometric mean concentration found in soils in this
country. One wastestream, finishing residues, was characterized
as potentially hazardous due to its content of flammable
solvents as well as from possible metal toxicity. Unless
noted otherwise, all discussion in this section of the report
pertains only to potentially hazardous process solid waste.
4.1.1 In-Plant Management. In-plant management of
solid waste is similar in most tanneries. Waste is collected
at the point of generation and placed (usually by hand) into
fiber or steel drums. Periodically the drums are moved to a
central loading area where they are unloaded into a tannery
or contractor-owned truck for hauling to a disposal site.
In some plants, notably split tanneries and some complete chrome
tanneries, conveyor or pneumatic systems are used to move
large quantities of blue trim and shavings to semi-trailers
or roll-off bins located outside the tannery building.
Wastewater treatment sludges accumulated in sewer sumps
are normally pumped out periodically into a contractor's
truck for disposal. Sludge from primary or secondary wastewater
treatment is pumped into tank trucks for hauling. If the
sludge is dewatered at the tannery, it is usually collected
in lugger containers or conveyed directly to a dump truck.
4.1.2 Collection and Hauling. Of the 41 tanneries
visited, 11 hauled their own waste to a disposal site and 30
utilized contractor services. Tanneries which haul their
own waste normally own dump trucks which are used for hauling
both solid waste and general supplies. Since the waste
(with the exception of wastewater treatment residues) is not
very dense, dump trucks with oversized bodies are often
used. Contract haulers normally use compactor trucks, although
roll-off containers, roll-off compactors, or dump trucks
are occasionally used.
Preceding page blank
135
-------
When contract haulers are used, tannery employees
normally take the waste from the point of generation to a
central pickup point in the tannery yard. When tanneries
haul their own waste, the truck picks up the waste at or near
the point of generation.
4.1.3 Treatment and Disposal. Treatment of potentially
hazardous waste in the leather tanning and finishing industry
is restricted to dewatering of wastewater treatment sludges.
Most tanneries which employ primary clarification and/or
secondary treatment of the wastewater utilize either
mechanical or non-mechanical equipment for dewatering the
resulting sludges. One tannery visited used gravity
thickening of sludge and 10 mechanical dewatering systems
(two vacuum filters, four filter presses, and four
centrifuges) were observed. The approaches to dewatering,
their effectiveness and extent of use are discussed in
Section 4.2
Potentially hazardous waste from tanneries is disposed
at three types of sites:
Dumps.
Landfills.
. Trenches, lagoons, pits, ponds, etc.
The dumps may or may not be burning. They are relatively
uncontrolled, are not covered, and little or no attempt
is made to protect the environment from their effects.
For purposes of this study, the term landfill includes:
Sanitary landfills (as defined later).
Engineered land disposal sites with cover applied
less than daily.
Dumps converted to landfills or non-engineered
landfills with cover applied less than daily.
Both publicly and privately owned landfills are utilized
by tanneries, and some sites are tannery owned. One landfill
visited during the course of the study was state certified
to receive hazardous waste.
Trenches, lagoons, and similar depressions are often
used for the disposal of potentially hazardous sludges and
slurries. They are normally only covered when completely
filled. Most sites utilizing this approach to disposal are
tannery owned. One trench disposal site visited was state
certified to receive tannery waste. It provided protection
of the groundwater and groundwater monitoring wells.
136
-------
Twenty-three disposal sites (.serving 113 tanneries)
currently receiving tannery waste were visited. Landfilling
was the most prevalent type of disposal operation seen,
and was the approach used by more tanneries than any other
disposal method. Open dumping was noted, especially in
New England (EPA Region I) where about 50 percent of tanneries
use this disposal mehtod. Only two tanneries disposed
of their waste in certified hazardous waste disposal
facilities. Further discussion of disposal practices is
included in Section 4.3
4.2 Present Treatment Technologies
Most tanneries which employ primary clarification and/or
secondary wastewater treatment find it both cost-effective
and desirable from the standpoint of disposal to dewater
the sludges produced. The water removed is normally
returned to the treatment system.
4.2.1 Non-Mechanical Dewatering. One tannery visited
utilized sequential settling to increase the solids content
of their wastewater treatment sludge prior to disposal. The
system consisted of a series of three tanks, following a
primary clarifier, in which the sludge is contained during
settling. The sludge settles in the first tank, the
supernatant from that tank is diverted to the sewer, and
the sludge from the first is conveyed to a second tank to
settle further, and the process is repeated a third time.
The clarifier plus the three settling tanks in series
produces a sludge with solids content of approximately 25
percent.
4.2.2 Mechanical Dewatering. Vacuum filter, filter
press, or centrifuge dewatering of wastewater treatment sludge
was employed by several of the tanneries visited. Vacuum
filters with either stainless steel or cloth membranes were
seen at two plants. They produced filter cakes of 25 to 30
percent solids. A ferric chloride solution (approximately
10 kg FeClo per 1000 kg of sludge at 25 percent solids) and a
saturated lime solution (approximately 45 kg lime per 1000
kg of sludge at 25 percent solids) were used as filter aids.
One tannery and three municipal treatment plants
(receiving between 80 and 95 percent of their flow from
tanneries) were visited which utilize centrifuges to dewater
primary or secondary wastewater treatment sludge. One
centrifuge was a basket-type, while the others were horizontal
decanter centrifuges. Use of a polymer yielded dewatered
sludge with about 25 percent solids. More details about the
municipal centrifuges and disposal of the solids generated
are included in Section 4.4.1.
Two tanneries visited used filter presses to dewater
sludge. A typical press has approximately 50 polypropylene
cloth—covered plates. Buffing dust is sometimes added as a
precoat and filter aid. A 40 to 50 percent solids filter
137
-------
cake is typically produced. The use of buffing dust as
a press aid reduces the number of different wastestreams
to be handled and stored for disposal. It also improves
the efficiency of the filter press, reducing the overall
quantity of waste requiring disposal.
4.3 Present Disposal Technologies
The 23 disposal sites visited during the course of
the study are characterized below with regard to operation
and ownership. The individual entries do not add to 23
since most of the landfill sites also included trenches
for sludge.
Operation
Method of Number Number of
disposal visited tanneries served
Dump 5 11
Landfill* 15 99
Trenches, etc.* 9 25
Agricultural
spreading 1 1
* One of which was state certified to receive
hazardous waste. These were not collocated.
Ownership
Number Number of
Owner visited tanneries served
Public 8 52
Tannery 5 5
Other private 10 56
4.3.1 Open Dumping. Open dumping of all types of
potentially hazardous waste into dumps and other uncontrolled
disposal areas is still a significant practice. Five dumps
receiving potentially hazardous waste from 11 tanneries
were visited; four were publicly owned; and one was owned
by a tannery. Leather trimmings, blue trim and shavings,
buffing dust, finishing residues and wastewater screenings
were all disposed at four of these dumps. Dewatered wastewater
treatment sludge was disposed at one of the sites, and one
dump received only finishing residues. Expanded to the
industry, it is estimated that 25 percent of the potentially
hazardous tannery solid waste was open dumped in 1974. It
is estimated that 90 percent of the dumps are publicly
138
-------
owned, 5 percent are privately owned and 5 percent are owned
by tanneries.
Host state and local officials and tanneries contacted
recognize the environmental inadequacy of open dumping as
a disposal method. Municipalities and tanneries commonly
cited economic considerations and lack of information on
adequate disposal methods as the reasons for the continued use
of open dumping. Due to the general awareness of the
environmental inadequacy of open dumping, it is anticipated
that this practice will be virtually eliminated by 1983.
4.3.2 Landfilling. Approximately 60 percent of
potentially hazardous waste is disposed in landfills. A
sanitary landfill may be defined as "a land disposal site
employing an engineered method of disposing of solid waste
on land in a manner that minimizes environmental hazards by
spreading the solid waste in thin layers, compacting the
solid waste to the smallest practical volume, and applying
cover material at the end of each operating day."24
Approximately 10 percent of the landfills currently (1974)
utilized by tanneries for potentially hazardous waste
disposal are "sanitary." An additional 25 percent of the
landfills used are engineered disposal sites but do not
provide daily cover. The remaining landfills are mostly
dumps which have been converted to landfills without being
engineered.
This study identified 15 landfills which accept
potentially hazardous waste from a total of 99 tanneries.
The ownership of these landfills is summarized as follows:
Number of
Type of operation Number tanneries served
Public 4 42
Tannery owned 4 4
Private 7 53
For the total industry, it is estimated that approximately
5 percent of the landfills utilized are owned by tanneries,
45 percent are publicly owned, and 50 percent are privately
owned. As can be seen, tanneries tend to prefer off-site
disposal if at all possible. However, some instances were
noted in which off-site disposal facilities would not accept
tannery waste. Reasons for refusal include the large volume
of some tannery waste and the lack of facilities to handle
tannery sludge which is often a liquid or slurry containing
less than 10 percent solids. Thus, a tannery is then forced
to operate its own disposal site. Public landfills are
preferred by tanneries to those privately owned because
of generally lower costs.
139
-------
Waste Types. Most landfills accept all types of tannery
waste, including wastewater treatment sludges. Potentially
hazardous waste (including sLudae) is usually mixed with
municipal refuse, compacted, and covered. Landfill operators
noted no particular difficulty in handling tannery waste
when it was mixed in this manner. However, large quantities
of only tannery waste, particularly blue trim and shavings,
were sometimes difficult to spread and compact. Landfills
accepting tannery sludge may either mix it with other refuse
(tannery and municipal) or segregate it. At sites mixing
the waste, operational difficulties have been encountered
if the sludge is not sufficiently dewatered. Landfill
equipment has become stuck in refuse/sludge landfills. However,
if the ratio at which the sludge is mixed with other refuse
in the landfill is appropriately controlled (as is the case
for the certified hazardous waste disposal facility described
later), operational difficulties are minimized. In one
instance, sludge (not dewatered) was dumped in a separate
area of a municipal landfill until it dried enough so that
it could be mixed with refuse.
Adequacy. Tannery representatives and local and State
government officials indicated that in their opinion sanitary
landfilling is an appropriate method of disposal for most
tannery waste. However, some felt that sanitary landfills
were not appropriate for the disposal of wastewater treatment
sludges. Due to the prevalence of and general satisfaction
with sanitary landfilling and lacking regulations to the
contrary, it is anticipated that virtually all waste, except
wastewater treatment sludges, will be disposed of in landfills
by 1983.
The potential for environmental damage as a result of
sanitary landfilling of potentially hazardous waste depends
upon the method of operation; the specific soil, geological
and climatological characteristics of the site; and the
composition and quantity of all of the solid waste disposed at
the landfill, not just the fraction hauled from the tanneries.
Although good engineering and site selection, in conjunction
with careful attention to operating procedures,.minimizes
the potential for leachate generation, it does not
eliminate the potential for surface or groundwater
contamination as a result of leachate generation.25 Data
is unavailable to determine the extent to which environmental
damage has resulted from landfilling of potentially
hazardous tannery waste. However, experience with tannery
waste and knowledge of landfill operation indicates that
the potential for environmental damage exists. s
140
-------
4.3.3 Certified Hazardous Waste Disposal Facilities.
In general, certified hazardous waste disposal facilities
have been developed through modification of conventional
sanitary landfills, or utilize trenches or pits. Additionally,
these sites have forms of groundwater protection and
operational procedures and safeguards required to properly
handle chemical waste. Such operations "provide complete
long-term protection for the quality of surface and subsurface
waters from hazardous waste deposited therein, and against
hazards to public health and the environment."27 Direct
contact between the waste and subsurface and surface water
must be prevented, and leachate contained and treated. In
addition, monitoring wells are often used for the sampling
of groundwater in order to detect any leachate contamination
as early as possible.
One of the privately owned certified hazardous waste
disposal facilities that was visited received all
potentially hazardous tannery waste, industrial and domestic
sludges, and municipal refuse. Loads of sludge are spread
between horizontal layers of municipal refuse at a mix rate
not to exceed 50 liters of sludge per m3 of dry material
(in order to minimize leachate formation). The perimeter
of the site is sealed with a compacted clay berm, and the 2.5
m deep lifts of solid waste are covered daily with clay,
thus the operations are similar to a sanitary landfill.
Leachate is collected and recirculated, and the gas
generated is vented to the atmosphere. Since annual
evaporation exceeds precipitation, leachate recirculation
provides adequate groundwater protection. All haulers
utilizing the site are required to have a permit for each
source of waste, describing the composition and quantity of
the waste. In addition, the site has monitoring wells which
are sampled quarterly by the appropriate state and local
agencies.
As discussed above in reference to landfills, the
environmental adequacy of a landfill depends upon its
design, location, operation, and the type and quantity of
waste being accepted. Unlike a landfill, however, a
certified hazardous waste disposal site, such as that
described in the preceding paragraph, provides assurance
of long-term protection of surface and subsurface waters
and against public health and environmental hazards from the
disposal of all types of potentially hazardous waste.
Based: upon interviews at 41 tanneries and other research,
it is estimated that 6 percent of the potentially hazardous
waste generated by tanneries is disposed of in this manner.
Most tanneries cited the limited availability of such sites
and the normally higher disposal charges as the primary
impediments to disposal of waste in certified hazardous
waste disposal facilities—a situation which is not expected
to change unless mandated by new regulations.
141
-------
4.3.4 Disposal in Lagoons t Trenches, Pits, and Ponds.
Lagoons, trenches, pits, and ponds are terms which are used
somewhat; Aftterjchangeably to refer to: natural Or manmade
depressionja.wluclt .are- used for/ the disposal of semi-solid
waste.-- This,. type of .'disposal differs- fronf landfilling
in that -.the waste J.« covered, only when the trench is filled.
This^study identified nine- sites of this type serving
a to taX, of 2£ .tanneries. Of the nine disposal sites, five
were tannery, owned , tw», were, private, and two were municipal.
Wastewatex treatment sludges. are- -the only potentially
hazardous waste .which, is ..disposed in lagoons. It is
estimated- that1 15 .pejrcefrt : of tannery" sludges which are
disposed , in lagoons ©retrenches* go to on-site facilities,
40 to pr^vate.sMes, and .-45 percent to municipal sites.
The environmental,. acceptability; of lagoons for the
disposal of semingelid waste is- dependent upon • the methods
and materials of construction, specif ic- local hydrogeological
conditions,. -and _ the ttypes of waste which 'are handled.
Unfortunately,, the potential for .significant contamination
of sxibsux f ace water-. s from .inadequately9 lined lagoons, both
old, and;>ne,wr. is :,4pErQcJ.able , due:. to improper location,
const rue U. on, and/or, .design.* •„ .Three Of the 'nine * lagoon
site^tid&Qtj^ed.; weore • constructed with1 compacted clay
liners.. ...jOne of- ^hqse; had monitoring wells afrid another
provided. fpr, treatment, of 'Ahe subsurface drainage from the
lagoon,.. > .jThe othe$r six sites, were constructed of native
earth matejrJtaliB <
The quantity .of. tannery sludge generated is estimated
to increase -7.8 , percent fro»'J.974 to 1983. It rs anticipated
that lpgoon«/ will continue vtO'be the primary irtethod of
disposal, for Cannery sludges ±f no' regulations to the
are imposed^ .
.4 .J8- 5 -. ., flgr.ieu-lturala.Spreaains. ' With reference to
potent^jLlyj- iiaza.rd^vs wasdb^, agricultural spreading refers
to the use of buffing dust and possibly other waste
consist^g pf relatively small:, leather particles as a
soil conditioner . • One, site was identified which received
settled, sludge from a , buffing/ dust ^wet" scrubber collection
device.' The-, buff ing du»t.» sludge -is dumped in piles- on the
edges of .^ejarn fields as /it is ..generated. The farmer spreads
the sl,u,3ge:, whenever he has an opportunity, and- the sludge"
is disced, into the.goii twice , a year. Growth of the corn
reportedly ^as ,ippjrovedr aincerthe, addition of the sludge.
Analy,3.4avof,.e3His!sidn>.s"p"ectrrosrcopy of -»slaiitpieS of corn
coJ,leat,ed<.friqm tjtie atr^a - receiving bti&f ing tfust sludge arid
from, a A ^adjacent farjniAdiicii deed-not -^receive" any tannery
waste^r i4i»d4.>qa'ted-.^:hat!,the concentration's o*f nicke^, total1
chromium r; j^ejad,^ artd:J.rojl :were -LO, i:2f 1C, and 5 timete greater
142
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respectively, in the corn taken from the field receiving
tannery waste. Since the significance of this observed
metal concentration phenomenon is unclear, the environmental
adequacy of this disposal practice is questionable.
In addition, buffing dust is considered to be a
potentially hazardous waste since it contains high
concentrations of lead, copper, and trivalent chromium.
Information is not currently available to determine if
land application of buffing dust will increase concentration
levels beyond acceptable levels or if ground and surface
water pollution will result. Consequently, this practice
cannot be considered environmentally acceptable until
further study is undertaken to determine the effects on
crop composition, soil fertility, and adjacent groundwater
and surface water quality.
4.4 Alternatives to Disposal
4.4.1 Municipal Sewage Treatment. Some tanneries are
located in communities where most of the wastewater received
at the municipal sewage treatment plant is discharged by
tanneries. These situations are somewhat unique to the
tannery industry and deserve mention.
The situation was particularly prevalent in New England
(EPA Region I) where three tanneries were visited which
provided 80 to 95 percent of the flow to municipal treatment
facilities. In other Mew England and New York (EPA Region
II) communities, up to 60 percent of the flow was contributed
by tanneries. Thus, the municipalities were treating
essentially tannery wastewater and generating and treating
tannery sludge.
In the community in which the tannery contributed 95
percent of the flow, the primary treatment plant sludge was
dewatered with horizontal, decanter-type centrifuges to
23 percent solids and disposed in trenches at the city's
landfill. In the two other communities, the tanneries
(a complete chrome tannery and a retan/finisher) contributed
about 80 percent of the flow. Both of the treatment plants
were constructed recently and neither was producing any
secondary sludge. Primary sludge was being dewatered
with decanter centrifuges with cakes about 25 to 28 percent
solids. One operation was disposing of sludge in trenches.
The other treatment plant was stockpiling the sludge near
the plant until a disposal site was found.
Neither of the secondary treatment plants was
experiencing major difficulties treating tannery wastewater.
The plant serving the complete chrome tannery was specifically
designed for tannery wastewater. It included a carbonation
tank followed by a second primary clarifier for the
precipitation of calcium carbonate (calcium from lime in
beamhouse waste). Influent to this plant has a BOD of over
2,500 mg/1 and effluent is approximately 100 mg/1 BOD.
143
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4.4.2 Source Reduction Through In-Plant Process Change.
Several tanneries have developed or are developing recovery
and reuse programs designed to reduce chemical consumption
and improve the quality of their wastewater. These programs
include systems for recovery and reuse of hide soaking
solutions, beamhouse sulfide liquors, and spent chrome
tanning liquors. As reliable systems are developed, it is
anticipated that the use of these recovery operations will
gradually become more widespread. The effect of this will
be a reduction in the quantity of wastewater treatment sludge
generated at tanneries utilizing primary clarification and/or
secondary wastewater treatment and which employ these
recovery and reuse systems.22
It may be possible to accomplish potentially hazardous
waste avoidance through the elimination of hazardous
constituents (with the exception of chromium) from the
chemicals used in the leather production process. Since
laboratory analysis of samples of cattlehides, sheepskin,
and pigskin before any tannery processing indicated that
lead, zinc, and copper are present at only natural background
levels, these metals appear in certain wastes as a result
of the production process. Tannery experts indicate that
these heavy metals are likely introduced in the retan, coJ,or,
and finish operations in the form of dyes and/or pigments.22*28
Contact with tanners and manufacturers of tannery chemicals
indicate that substitute products have been developed which
can be used in place of those containing lead, copper, and
zinc. Such substitutions have already been adopted for
chemicals containing mercury. However, the practice has not
been extended to pigments containing other hazardous
constituents because of the slightly different product
obtained, the increased expense associated with the use
of substitute organic dyes and pigments, and the general
reluctance to change. With the advent of regulations
governing the disposal of potentially hazardous waste, however,
tanneries may find it cost-effective to utilize substitute
organic dyes and pigments.
A few tanneries are looking to process and equipment
changes that will improve overall tannery efficiency and
coincidentally reduce waste quantities. "Splitting to
weight," the extremely accurate splitting of tanned leather,
is being employed by some tanneries to essentially eliminate
the shaving of entire sides to obtain uniform thickness.
Use of this technique reduces processing costs, increases
the value of splits produced and reduces the volume of
shavings requiring disposal.
The process, however, requires the use of sophisticated,
expensive equipment and was only seen in a few tanneries
visited during this project. It was the opinion of several
tanners that the widespread use of splitting to weight will
evolve slowly due to current investments in conventional
144
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splitting and shaving equipment, the high cost of the new
machines, and reluctance on the part of some tanneries to
change from traditional processes.
The segregation of wastewater streams within a tannery
could reduce the quantity of potentially hazardous waste
requiring land disposal. No hazardous constituents were
found in beamhouse waste. Thus, if beamhouse wastewater
(high in suspended solids) was segregated and separately
clarified, the resultant sludge would not be a potentially
hazardous waste, and in fact likely could be marketed as
a soil conditioner due to its protein and lime content.
One tannery is known to be using this approach. Wastestream
segregation would require widely varying amounts of plant
modification.
The process modifications described above are in
various stages of development from experimental through
pilot plant and full scale operation. However, none of
the processes are in widespread use in any of the tannery
categories, let alone the tanning industry as a whole. In
addition, it is doubtful that many of the in-plant processes
will come into widespread use by 1983.
The impression gathered from tannery officials during
the course of this project was that tanning is considered
an art. Each tanner feels that he knows the "tricks of
the trade" as far as the production of his particular leather
is concerned. Tanners strive to maintain a quality product
of consistent color, texture, pattern, etc., in order to
retain their established customers. Some tanners are not
sure that they can reduce their chemical usage, use •:
reformulated finishes, reuse chrome, etc., and still produce
the same product, and thus are reluctant to make even minor
changes in their processing.
Therefore, tanners will move slowly in altering their
processing procedures. Since the in-plant process changes
are not applicable to nor likely to be adopted by all
tanneries in a particular category, no attempt has been
made to suggest them to the entire industry. Consequently,
in-plant process changes which impact on the quantity or
nature of potentially hazardous waste have not been included
as any level of treatment/disposal technology.
4.4.3 Sale as By-Products. Economic feasibility is
currently the primary factor affecting by-product utilization
of potentially hazardous waste. Following is a list of the
types of potentially hazardous waste which are currently
saleable:
145
-------
Wastestream
By-product use
Blue-itrim and.-shavings
.Solvent-based if inish
-residues
leather i.trimmiisgs.
Fertilizer
Hog feed supplement
Glue
Solvent recovery
Glue
Grafts—-small:leather
articles
Withithe exception of 'solvent recovery, by-product
utilization of;potentially ^hazardous waste is volatile and
dependent ^upon? loeat^oru , finished and unfinished leather
trimmings are sometimes sold to foreign leather goods
manufacturers ijv countries such as Korea, Japan, Hong Kong,
and Taiwan, where, because of cheap labor, this material
can be haod-rsorted and manufactured into small leather
products;*-: However,'.this market depends, on a .variety of
unstable variables,'including freight-rates, hide prices,
labor .cost, and availability/ and market demand...
The major type of potentially? hazardous waste sold
is blue trim and shavings. These are, and have been, sold
to producers of: fertilizer', animal feed'supplements, and'
glue. These: markets are apparently declining as: evidenced
by the facts :that, within -±he". last-.two decades the number of
fertilizer producers .utilizing leather waste.has been reduced
from 28 to-3. In addition, glue manufacturing from leather
waste has ^essentially .ceased. ;• However, tanneries located
in the Midwest are abjleJto..sell their blue trim and shavings
to a .producer,of fertilizer-used principally in citrus .
groves:., and to •&-. lesser extent in other orchards. Similarly,
some tanneries also sell blue triro^andL shavings for use a
a hog .feed supplement> c;
:. Sale Qf- potentially hazardous,/ waste for; by-product
uses is gncoutagedas an alternative to disposal if the
ultimate-xuse ©f the; waste is. environmentally sound. Blue
trim, and rsfeavings are jEonsidered potentially hazardous due
to their |dgh,trivalent chromium,content. Information in,
the.literature indicates t^at fcrivalent chromium is hazardous
to aquatic organisms and, to'lower forms of terrestrial
plant life, but not to mammals and higher plant forms.
Consequentiy» the use:iof -blue trim;and shavings-as a hog
feed,.s»pp:lemen:'t is approved ,,bys 0SDA (chrpmium content not
to exc;e$d..,275 ppm) .v.,Similarly, the use of: this waste as
an orchard•;fertilizer is encouraged as long as the application
does not increase concentration levels beyond acceptable
levels and ground and surface water pollution does not
result from the practice. Use of the waste for other
146
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fertilizer applications, such as vegetable crops, must be
studied further before the environmental adequacy of the
practice is known.
4.5 Approach to the Selection of
Treatment and Disposal Technologies
4.5.1 Technology Levels. For purposes of this report,
three levels of technology for the treatment and disposal
of potentially hazardous solid waste from leather tanning
and finishing establishments were identified. These
technology levels are characterized as follows29:
Level I —Technology currently employed by typical
facilities, i.e., broad average present
treatment and disposal practice.
Level II —Best technology currently employed.
Identified technology at this level must
represent the soundest process from an
environmental and health standpoint currently
in use in at least one location. Installations
must be commercial scale; pilot and bench
scale installations are not suitable.
Level III—Technology necessary to provide adequate
health and environmental protection. Level
III technology may be more or less
sophisticated or may be identical with
Level I or II technology. At this level,
identified technology may include pilot
or bench scale processes, providing the
exact stage of development is identified.
The definition of Level III technology as defined in
this report represents contract judgment, and not that
of the EPA. This level of technology as defined for a
particular potentially hazardous wastestream and/or process
type is merely an attempt by the contractor to define an
environmentally acceptable technology. Thus, the technology
level defined should not be interpreted as a basis for
future regulations. It is not based on cost-benefit,
economic, or other analyses required to appropriately define
Level III technology.30
4.5.2 Treatment. Treatment is applicable to only
one wastestream from tanneries. Sludge from wastewater
pretreatment or treatment facilities can be dewatered.
Currently, tanneries in both the complete chrome and
beamhouse/tanhouse categories dewater sludge. The removal
of as much moisture as possible has lead to reduced on-site
storage requirements, improved hauling, more acceptable
disposal practices, and generally lower disposal cost. The
previously described approaches of gravity and mechanical
147
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dewatering appear to be the only treatment methods applicable
to wastewater treatment sludges. The single instance of
gravity dewatering is being replaced by a filter press.
Therefore, in those categories in which significant sludge
is generated, mechanical dewatering is suggested for
waste treatment.
4.5.3 Disposal. The potential hazard from tannery
waste so designated comes from the possibility of heavy
metals leaching from disposal sites and entering the
surface or groundwater system. Thus, Level III technology
will have to incorporate some safeguard to prevent leaching.
On the other hand, no special handling methods or equipment
are required at the disposal site for tannery waste.
Level III technology for disposal of potentially hazardous
waste is the use of landfills With a leachate collection
system and an environmentally acceptable means of treatment
and/or disposing of the leachate. This approach will
prevent any heavy metals leached from the waste from
entering the surface or groundwater system.
The other potential hazard associated with tannery
waste is the flammability of some finish residues. These
are disposed in relatively small quantities and on
infrequent bases, e.g., 200 to 400 liters (50 to 100 gal)
per week. Therefore, the normal, safe operation of a landfill
with leachate collection should provide adequate protection
from this potential hazard.
Tanneries generating potentially hazardous waste
predominantly use off-site disposal. This is also true of
the best current practices (Level II technology). Therefore,
'only off-site disposal is listed on the technology level
tables in Sections 4.6 through 4.11. However, equivalent
on-site disposal is also considered adequate.
4.5.4 Outline of Subsequent:Sections. The six categories
of tanneries generating potentially hazardous waste are
discussed in turn in Section 4.6 through 4.11. The data
presented in Section 3.0 for' each category of tannery are
summarized. Potentially hazardous wastestreams, their
hazardous constituents, waste generation factors, and
national totals for each waste' type are shown.
The three treatment and disposal technology levels
developed are presented for each category of tannery.
In some instances, more than one alternative is listed for
a single technology level. Each technology is evaluated
using the following criteria:
148
-------
Current usage in the industry.
Risk potential.
Environmental adequacy (present and future).
Monitoring techniques.
Limitations.
Impacts.
Implementation time.
Treatment and disposal technologies pertinent to
each category are discussed. The types and numbers of
operations are listed. These tables provide the basis for
the cost estimates presented in Section 5.0 for each
level of technology for each category of tannery.
4.6 Treatment and Disposal; Complete Chrome Tanneries.
The potentially hazardous waste currently (1974)
generated by complete chrome tanneries is summarized as
follows:
Wastestream
Trimmings and
shavings
Unfinished
leather trim
Buffing dust
Finished
leather trim
Finishing
residues
Wastewater
screenings
Sewer sump
: sludge
Dewatered
wastewater
or treatment
sludge
Potentially
hazardous
constituents
Cr
Cr, Pb, Cu
Cr, Pb
Cr, Pb, Zn
Cr, Pb, Zn
Cr, Pb
Cr, Cu, Pb, Zn
Generation
rate • (wet/dry
kg per 1000
eg. hides)
1,260/540
114/100
27/25
220/200
150/45
390/90
2,700/300
Nat't. total
(wet/dry
metric tons
per year)
21,000/9,100
1,900/1,700
460/420
3,700/3,400
2,500/760
6,600/1,500
37,000/4,100
Cr, Cu, Pb, Zn 10,000/2,400 100,000/24,000
Treatment and disposal technology levels for complete
chrome tanneries are presented in Table 44.
4.6.1 Treatment. The only type of potentially hazardous
solid waste from a complete chrome tannery which is
''normally treated is the sludge from wastewater treatment or
pretreatment facilities. The treatment utilized is
mechanical dewatering (filter press, vacuum filter and
centrifuge) which is discussed in Section 4.2 Individuals
149
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TABLE 44
COMPUTE CimOHl
UI
AJMUM of Matoi io«.ooo(Mt)/it.ooofdry) Mtcio
Pkyalcal aad OMloal PrapaMiMi Seal-Mild tad
Level 1
. Typea of *»<•• «n types
• tMhaolooy Ofl-alto laadflll
* ^SMT ••**"*?*
• % Ojf C*A^le%* CbffMO M
• f of cnaploto.CaWaa* U
. Mat
, . *
• rito o» toploaloo iltoM
-*-«"«•»" "•*"
• Pollnti«ii Nedarato
n.
• Moitortat Taehalajioa • Mno
. UMtatittoa Md riro kaiard and
•voMana «orter aafaiy.aad
larjo quMtitU*
of wakoa
*•>••>• «otar pollution pataatial
. ^U^u.i«iTiM uaiaiud
tona par yaar 11*741
aolid vitb tonie haavy Mtala (P».ta.C«.Crl. flanHftla aalvMta
Lavol IIZ
l***l Ii **«. i «it. i
t having*
II Other naataa
II talo aa a bv-prodoet
II Oavatar alodfaai oil naata*
to off-aita eaztlfiad aataidoua
vaato dlapooal faaility
II U
II «
II M
II • '
II Ml
»l *H
pofe la off-alto
linod trciichM at
UrJsIll wltb
lcjc!ut* ealloetko
II **lo aa a by>
product
II Off«aito laadflll
vitb teacbata
colloatlM
II «
II M
II 0
II •
II I*
II t
lall Ml
II »Ilgbt
Ull Ml
II MlfM
1.1.411 Ml
II Caeolloot
Ull CrauBdvatac walla
Ull foil cooditloao
1} voUtlla MIBM
l.I.tll Ml
Ull laotallod 1411 I yoara
II >ot applirakU
•ounoi MS
-------
experienced in tannery wastewater treatment prefer filter
presses for dewatering tannery wastewater treatment sludges.
Although centrifuges, vacuum filters, and filter presses
all seem to perform acceptably, the higher solids content
of sludge dewatered with a filter press may favor its
use in the future.
4.6.2 Disposal. All chrome tannery solid waste, with
the exception or sewer sump or wastewater treatment sludges,
is normally combined for disposal purposes. Nineteen disposal
sites receiving complete chrome tannery waste other than
sludges were visited:
On-site dump--1.
On-site landfill—1.
Private landfill—8.
Municipal dump—2.
Municipal landfill—7.
Both tanneries which operate on-site disposal facilities
also dispose of wastewater treatment sludges on-site. Zn
both cases, the land and equipment were purchased primarily
for sludge disposal.
Sixteen sites accepting sludge from complete chrome
tanneries were visited:
Private landfill—6.
Municipal landfill—3.
On-site (tannery) lagoons—4.
Private (off-site) lagoons —2.
Private certified hazardous waste disposal
facilities—1.
Pour tanneries operated on-site tiludge disposal facilities
because the local private or municipal disposal sites would
not accept tannery sludge.
It is estimated that on a national basis 15 percent
of the potentially hazardouswaste generated by complete
chrome tanneries currently (1974) is disposed of in on-site
facilities. Fifteen percent is disposed in off-site lagoons
or trenches; 16 percent is disposed in off-site dumps;
50 percent is diposed in off-site landfills* and 4 percent
is disposed in certified hazardous waste disposal facilities.
4.7 Treatment and Disposal; Sheepskin Tanneries
The types and quantities of potentially hazardous solid
waste generated by the sheepskin tanning industry are
summarized below:
151
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Wastestream
Chrome
fleshings
Buffing dust
Leather trim
Wastewater
screenings
Potentially
hazardous
constituents
Cr
Cr, Pb, Cu, Zn
Cr, Pb, Cu
Cr, Pb, Zn
Generation
rate (wet/dry
kg per 1000
eg. hides)
1,200/300
56/50
170/140
230/50
Nat'l. total
(wet/dry
metric tons
per year)
3,000/750
140/130
420/350
570/120
Treatment and disposal technology levels for sheepskin
tanneries are summarized in Table 45.
Sheepskin tanneries do not treat any of the potentially
hazardous solid waste generated. All of the potentially
hazardous waste listed above is normally combined in the
plant and disposed together. Six disposal sites receiving
potentially hazardous waste from sheepskin tanneries were
visited. One was a municipal dump, two were municipal
landfills, and three were private landfills. Since most of
the sheepskin tanneries are located on the East and West
Coasts in relatively urban areas, on-site waste disposal is
not normally utilized.
On a national basis, it is estimated that 40 percent
of potentially hazardous waste generated by sheepskin
tanneries currently (1974) is disposed in municipal dumps,
30 percent in municipal landfills, and 30 percent in
private landfills.
4.8 Treatment and Disposal; Split Tanneries
The four types of potentially hazardous waste which is
generated by split tanneries is summarized below:
Wastestream
Trimmings,
splits &
shavings
Buffing dust
Unfinished
leather
trim
Wastewater
screenings
Potentially
hazardous
constituents
Cr
Cr, Pb
Cr, Pb
Cr, Pb
Generation
rate (wet/dry
kg per 1000
eg. hides)
8,200/3,700
200/180
230/200
22/5
Nat'l. total
(wet/dry
metric tons
per year)
28,000/13,000
690/620
790/690
75/17
152
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TABLE 45
TUMMER MO DISPOSAL Tl
FOR SflEBSRIli TAMHBKY
Aoount of Mastei 4.100(wet)/I,)00(dry) aetrie ton* per year
Physical and Chevies! Propertiesi Solid, containing toale Heavy M*als (Pb,So,Cu)
Uy«l I Uxl II l*nl III
Types of Nastm All typu VMM M U**l X Ul types
•logy OM-eite Instill Oil-site Undf ill
with leaetete
eelleetiea
BstiMte «f current
ui
- » of Sheepskia
twweriee
- I of 8he«p«kia
Tanneries
Uek
• fire er faploeie*
• traaspertetiea
• Vellotiea
•0
2C
Nsalteriav
Uaitetiene ea«
i
Seleted
lapsets
•is*
PsU
fair
Corf eee and/or
pettaeiM potential
Inetelle4
9
0
flight
•li«
•il
iter welie
•oil conditions
-------
Treatment and 'disposal- technology levels' fior split
tanneries are summarized in- Table 46 .
None of the potentially hazardous waste from a split
tannery receives- treatment of any kind prior to disposal.
All split tannery waste is normally combined in -the plant
and disposed together. Three • disposal sites receiving
potentially .hazardous waste were visited; one was a municipal
landfill, and two were private landfills. Since split
tanneries are normally located in urban areas, virtually
all split tannery solid waste is disposed.9, off -site.
Available information indicates that; 70 percent of the
potentially hazardous waste generated by- split tanneries is
currently (1974 K being .disposed 'in municipal slumps and that
30 percent is c be ingr disposed in landfills, the high
percentage using dumps is due to the location of -these
operations — Mew England (EPA Region I) where dumps are common.
In addition, the split tanneries in the Midwest (EPA Regions
V and VII) are able to sell their trimmings and shavings
and thus they . are .not waste .
4 . 9 ^Treatment and Disposal ; Leather -Finishers
The potentially hazardous waste which is generated/ by
leather finishers is listed below: *
Generation Nat'>'^L. total
Potentially rate (wet/dry (wet/dry
hazardous kg per 1000 metric tons
Wastestream constituents eg. hides) per, year). i
Buffing 'dust £r> Pb 11/10 61/56
Finishing
residue Cr, Pb, Zn t
solvents 150/45 830/250
.Treatment and disposal ^technology "levels for 'leather
finishers are summarized in Arable 4?. '
^either of this potentially "hazardous waste is treated
prior to^; disposal. Instead, this ah:d Other waste ^non-process
waste from ?off ices, etc.) Sis? normally combined either during
collection spr [hauling: to the; disposal
' "
finee |eoss#ntially £ll> Leath'er "t ii&shers are located in
urban* areas >arid because 'finishers do not generate large
quantities of waste, off-site facilities are 4ised for all
waste disposal.
Three disposal sites receiving potentially hazardous
waste from finishers were visited, of which two were
municipal dumps, and one was a private landfill'. Although
use of municipal dumps is typical for their location,
disposal in dumps is not typical for leather finishers.
Therefore, estimates of the type of solid waste disposal
X&4,
-------
TABLE 46
TREATMENT ADO DISPOSAt TECHNOLOGY LEVELS
POR SPLIT TANNERY
Wl
Ul
ABbunt of Nestei U.000(wetl/7.900(dryl
Physical and Chemical
. Types of Mattes
. Technology
. Cstinate of
Current usate
- % of S;.lie
T«r.A«r :•••
- • of T« fineries
. Risk
• Piro or Explosion
• Transportation
- Pollution
. Present Adequacy
. Future Mi-quaey
. Monitoring Technio/ies
. tlmit«tl'jfia and
Problems
. non-Land Piloted
Injects
. Inploaantation Time
Propertiesi Solid.
Level I
All types
Off-site dumping
70
17
Nil
Slight
Moderate
Poor
Poor
*"
metric tons per year
Containing Tmic Heavy Metals (Pb and Crl
Level III
Level II Alt, i
11 Trimmings and All types
Shavings
at Other wastes
11 Sale as a by-product Off-site landfill
at Off-site landfill with Icachate
collection
1*2) 10 0
112) 7 0
11 Nil Nil
21 Nil
11 Ml Slight
at Slight
11 Ml Ml
at Moderate
11 EBcellent Good
at r-ir
***• '
11 Trimmings and Shavings
at Other wastes
11 Sale as a by-product
21 Off-Site landfill with
leachate collection
11 «
at o
it i
at o
uat MI
11 Ml
at Slight
uat MI
U2I Excellent
II Excellent Cood Uat Excellent
at Pair
Oroundwater veils at eroundMter wells
It Volatile sad Ceo* soil conditions
graphically concen-
trated market
11 Volatiband <«M>.*r«eh-
ically concentrate!
market
a) Soil conditions
Surfw and/or ground- a> Surface and/or ground-
water pollution potential ««« pollution potential
Installed
IMl Installed a years
2 year*
Sourest SC8 Engineers
-------
TABLE 47
1MKIMOT AM DISPOSAL
PC* uM«ft pnisms
af Maatai tOO(wat>/MO aa?rie taaa par yaar (1*94)
Thyaical and =ha*ieai *re?arbiaa- Baffiaa «aat aoataiaa
fialsM.fi raai«aaa =«-.t«in heavy -Mtal'a (Cr,Pa.Ba)i aad
ea«ala (Cr.fb)i
am f Unubl*
of Haataa
Taehnolofy
tatiaata of Corrane
• %'of finlahara
• t of riniahora
Kiak
• Fira ar Explaaiaa
- Traaapertafie«
• fellatiaa
Presc-nt
Putiira
Monitoring Taehniqua'a
Ltaitatiuna and
Non-Uteri' Moiatad
Impacta
Isplea-eatatioa Tima
fc»»al 1
t) MuCfiaa da
1) Maiafclaff
UI) Off«ai«« laadfiU
14X1
ua> «t
1) -SlioM
I) -
il
X) iliatrt
I)
»
il Pair
2) Poor
1) Pa'.-
X) roar
1) Soil condition*
X) fire bacard, aail
conditions and
work'ar 'aafoty
1*2) Surface and/or greuad-
vatar poilntioa potential
Xnataltad
111
1) Buffing «aat
XI Piaiabing raaiduaa
I) oer-aita landfill
Mitk laaehata
eatlaetiaa '
X) Off-ait*
0
0
1} Ml
2) Slight
1) Ml
X) Slight
UX) Ml
1) Excellent
X) Goad
1) Bxeallant
2)
1*2) Craundwatar walla
1*2) sail conditions
1»2) 2 yaara
Saurcai SCS Sagiaaara
• Buffing diiat'eeneaiaa aaavy
lai fiaiahiag
la.
156
-------
facilities utilized nationwide are based upon information
obtained for solid waste from complete chrome tanneries
(excluding wastewater sludges). Thus, on a national basis,
35 percent of the potentially hazardous waste generated
by finishers is currently (1974) disposed in municipal
landfills, 40 percent in municipal dumps and 25 percent
in private landfills.
Level III technology calls for finishing residues to
be disposed in certified hazardous waste disposal facilities.
This is because these sites are more likely able to handle
the potential fire hazard from the residues which make up
a larger proportion of a leather finisher's waste than that
of any other tannery category. However, if there are no
certified hazardous waste disposal facilities in the area,
landfills with leachate collection could be used for
disposal as long as the finishing residues are mixed in with
other waste so as to prevent flammability hazards.
•
4.10 Treatment and Disposal; Beamhouse/Tanhouse Facility
The potentially hazardous waste which is generated
by the beamhouse/tanhousefacility is:
Generation Nat'l. total
Potentially rate (wet/dry (wet/dry
hazardous kg per 1000 metric tons
Wastestream constituents eg. hides) per year)
Wastewater
sludge Cr, Cu, Pb, Zn 8,500/2,500 18,000/5,300
Treatment and disposal technology levels for beamhouse/
tanhouse facilities are summarized in Table 48.
4.10.1 Treatment. Wastewater treatment sludges are
normally treated prior to disposal. The only type of
treatment utilized is dewatering, and this is accomplished
on-site by non-mechanical (sequential settling) or
mechanical (filter press, vacuum filter or centrifuge)
means. Two beamhouse/tanhouse facilities which treat their
wastewater pretreatment sludge were visited. One used the
sequential settling and one used a filter press. In order
to reduce hauling and disposal charges by further reducing
the moisture content of the sludge, the plant currently
employing the sequential settling method of sludge dewatering
is in the process of installing a filter press. Both
plants indicated their preference for the use of filter
presses for sludge dewatering because they are reliable and
effective (yielding a 40 percent solids filter cake).
157
-------
TABLE 48
***
of Iteafeat )l,0«»f«a*l/S.tMM*y»
rhyaical and CbaaUal »co*artiMii MttdoM M^ at 'to
heavy «ofcala (ffV.ttl
'§•* fM* llt*«>
Type* of «••«••
in of C-«iM
fill i« »tf
Salt*'
Citmnt
• -% o(
Of
- • of
Tanhovs*
!>isk
M
a
Of BiplOMt
• TraiMportotiM
- POtlutiOA •'
•a
MI
rat*
ruturo Adoquaey
toir
tlaltatiinc and
imea* potlwtioa
•ail
Ia*taUo«
«iay*M in off-
•it* landfill
•itk l«aehata
0
•a
Ml
ll«0t
OTlU
years
TiM
Soureei SCS Bnginoora
158
-------
4.10.2 Disposal. One private disposal site which
accepts wastewater pretreatment sludge from a beamhouse/
tanhouse facility was visited. The site is state certified
to accept tannery waste. At this disposal site, the
sludge is placed in clay-lined trenches (Level II technology)
The bottom of the trenches are sloped to allow excess water
from the deposited sludge to drain to the low end. As this
liquid accumulates, it is pumped out of the trench into an
adjacent evaporative lagoon. When the trenches become
approximately one-half filled with sludge, they are
completely covered and sealed with the clay soil which was
originally excavated. The site has only recently been
put into operation and the first sludge trenches constructed
are still being filled. The site operators indicated that
they have not encountered any particular problems with
operation of the site.
On a national basis, it is estimated that 40 percent
of the potentially hazardous waste generated by beamhouse/
tanhouse facilities is disposed in facilities utilizing
trenches or lagoons and that 60 percent is disposed in
off-site landfills. It is known that by 1983 at least
one new beamhouse/tanhouse facility probably will be
operating with on-site evaporative lagoons.
4.11 Treatment and Disposal; Retan/Finishers
The six types of potentially hazardous waste generated
by retan/finishers is summarized below:
Wastestream
Trimmings 6
shavings
Unfinished
leather trim
Buffing dust
Finished
leather trim
Finishing
residues
Screenings
Potentially
hazardous
constituents
Cr
Cr, Cu, Pb
Cr, Pb
Cr, Pb, Zn
Cr, Pb, Zn
& organic
solvents
Cr, Pb
Generation
rates (wet/dry
kg per 1000
eg. hides)
1,300/540
110/100
27/25
220/200
150/45
40/10
Treatment and disposal technology levels for
finishers are summarized in Table 49 .
Nat'l. total
(wet/dry
metric tons
per year)
2,600/1,100
240/210
60/50
460/420
310/90
80/20
retan/
159
-------
TABLE 49
vn
AMD DISPOSAL TBCHSOLOCT LEVELS
FOR MTAN/PXNI8HRRS
Anouat of ttastoi 4.SOO(«ot)/2.300fdry) a*trio tons por yoar
Physical and Choaical Properties! Planaablo. sail-solid oad solid with tonic heavy metal• (Pb,Sn,Cu,Cr)
Level 111
Typos of Mastos
tavoi I
All typos
Off-sito landfill
• Istinato of Cotrott
Usa
-------
None of the above waste types are treated prior to
disposal. All of the waste is normally combined for disposal
purposes either during collection, hauling to the disposal
site, or in the disposal operation. Four disposal sites
receiving potentially hazardous waste generated by retan/
finishers were visited, of which two were municipal dumps
and two were municipal landfills.
Operations at one municipal dump have been altered
because of the acceptance of tannery waste. Until
recently, the tannery waste was mixed with municipal refuse.
When this mixture burned, (reportedly a frequent occurrence)
citizens complained about the obnoxious odor. To alleviate
this problem, the tannery now disposes its waste (primarily
blue trimmings and shavings) in a separate area of the dump.
Weekly, a crawler dozer spreads the waste and covers it
with imported cover material. This procedure prevents the
trimmings and shavings from burning.
It is estimated that on a national basis 35 percent
of the potentially hazardous waste generated by retan/finishers
is disposed at municipal landfills; 20 percent is disposed
at private landfills; 15 percent is disposed at on-site
facilities; and 30 percent is disposed at municipal dumps.
4.12 Treatment and Disposal Technologies
and Waste Quantity Summary
The treatment and disposal technologies and the current
(1974) distribution of waste between the three levels
of technology are summarized in Table 50 . As shown,
landfilling is the most common Level I and Level IX disposal
technology. For all categories of tanneries, a landfill
with leachate collection provides adequate environmental
protection (Level III). Other acceptable Level III disposal
technologies include landfills and lined trenches certified
for hazardous waste disposal.
Wastewater pretreatment/treatment sludge is the only
type of potentially hazardous waste which requires treatment
prior to disposal. Dewatering of the sludge prior to disposal
is the only type of treatment required. Sludge dewatering
is common at large tanneries which treat their wastewater,
and is included in all levels of technology for complete
chrome tanneries and beamhouse/tanhouse facilities which
generate sludge.
Comparison of the quantity of waste going to Level III
with the total quantity of potentially hazardous waste
generated reveals that only 6 percent is going to Level III.
Similarly, 12 percent is going to Level II and 87 percent
is going to Level I. Note that the sum of Level I, II, and
III percentages is greater than 100 due to overlaps between
the various levels, as shown in Table 50 .
161
-------
TABLE 50
—•*•----=—— -—
n MtfMtt ti
Mf«nUM BMMOOM
MO 0im9Kt nemetoov tcmi MB
9k
M
-------
As shown approximately 34 percent of the total quantity
of potentially hazardous waste generated by the tanning
industry comes from complete chrome tanneries and goes to
Level I (landfills). Similarly, 7 percent of the waste
comes from split tanneries and goes to Level I (dumps)
and 8 percent comes from beamhouse/tanhouse facilities and
goes to Level I (landfills).
Since about 34,000 metric tons (wet weight) of sludge
from complete chrome tanneries and 12,600 metric tons
(wet weight) of sludge from beamhouse/tanhouse facilities
goes to Level I disposal (landfills), 57 percent of the
waste going to Level I treatment and disposal technology
is wastewater treatment sludge. Similarly, 44 percent of
the waste (wet weight basis) going to Level XX and 95 percent
of the waste going to Level XIX is wastewater treatment
sludge.
163
-------
SECTION 5.0
COST ANALYSIS
In this section, the costs associated with the three
levels of potentially hazardous waste treatment and
disposal technology in the leather tanning industry are
developed. The cost information in this section is
primarily based on data collected during interviews with
tannery representatives. As necessary, additional
information is included from equipment suppliers, published
literature, and government sources. Wherever possible, the
cost data presented is from actual installations, and from
prices quoted by tannery solid waste disposal contractors.
The general assumptions and bases for the cost
analyses are presented in Section 5.1. The costs associated
with on-site treatment of potentially hazardous waste are
presented in Section 5.2, and the costs associated with
contractor hauling and disposal are presented in Section
5.3. The costs of the various levels of treatment and
disposal technology for typical plants from each of the six
categories of tanneries generating potentially hazardous
waste and for the industry as a whole are presented in
Section 5.4, and the variables which effect these costs
are discussed in Section 5.5. An example of the cost
calculation methodology utilized to develop the treatment
and disposal costs for the typical plants is presented in
Section 5.6.
5.1 Bases and Criteria for Cost Estimation
The basic information utilized to develop the cost
estimates presented in Section 5.4 is shown in Table 51
and discussed in the following paragraphs.
5.1.1 Capital Costs. As used in this analysis,
capital costs include all expenditures associated with the
development and installation of treatment and disposal
facilities. These costs include engineering consulting
services, equipment purchase and installation, electrical
and plumbing connections, buildings, start-up costs, and
land costs where applicable. Capital costs known for
specific plants were factored to account for capacity
differences and averaged to develop the costs for the
typical plants.
5.1.2 Interest Costs. It has been assumed that private
debt financing is used for treatment and disposal facility
investment. In addition, the cost of capital has been
assumed to be equal to 10 percent annual rate of interest on
investment.
Preceding pan blank
165
-------
TABLE 51
BASES AND CRITERIA FOR COST ESTIMATION
Cost of
Capital - 10 percent annual interest
Time Index - December 1973 dollars
Depreciation - Straight line over useful service life of
equipment
Estimated Equipment Lifei
.. mobile — 5 years
. stationary—10 years
Land Value - $50,000/ba (S20,000/ac>
Operating Costs>
Labor (including 33% fringe benefits) - $4.80 per hoar
Supervision (assumed) • 10 percent of labor
Maintenance » average of costs reported by applicable
tanneries visited
Materials • average of costs
Insurance and Taxes * 2 percent of capital
Electrical Power « $0.02 per
Contract Services » average of costs reported by
applicable tanneries visited'
Sourcei SCS Engineers
166
-------
5.1.3 Time Index for Costs. All cost estimates have
been adjusted to December 1973 dollars, using the Chemical
Engineering (CE) Plant Cost Index.
5.1.4 Useful Service Life. The useful aervlce life
of treatment and disposal erjii iiwuMit v.-iricN ttoptJiulltuj UIH-W
factors such as usage pattern and maintenance schedule.
Based upon information obtained from private industry
sources, the following generalizations have been made
with regard to the service life of treatment and disposal
equipment used in the leather tanning industry:
Lagoons—20 years.
. Mobile equipment—5 years.
Stationary equipment—10 years.
5.1.5 Depreciation. For the purposes of this cost
analysis, it has been assumed that the salvage or recovery
value of treatment and disposal equipment is zero at the
end of its useful service life. In order to annualize the
capital costs incurred by tanneries as a result of treatment
and disposal equipment, straight line depreciation has been
utilized over the useful life of the service equipment.
5.1.6 Operating Expenses. The annual costs associated
with operating the treatment and disposal facilities include
labor, supervision, maintenance, taxes, insurance, materials,
and energy. For purposes of clarity, costs associated
with energy consumption are itemized separately from other
operating expenses, as are maintenance costs. No interest
costs for operating capital are included in the operating
expenses.
5.2 On-Site Waste Treatment
Sludges resulting from primary and/or secondary
treatment of wastewater at beamhouse/tanhouse facilities
and some complete chrome tanneries are the only type of
potentially hazardous waste which receive treatment prior
to disposal. All sludge treatment is performed on-site,
except for tanneries discharging to municipal wastewater
treatment facilities, and consists of non-mechanical
(sequential settling) or mechanical dewatering systems.
Since only one tannery was identified which utilizes a
non-mechanical sludge dewatering system and this tannery
is currently in the process of replacing it with a filter
press, only mechanical systems are considered in these
cost estimates.
Filter presses, centrifuges, and vacuum filters are all
used in a variety of situations for dewatering tannery
wastewater treatment sludges. As a result, the cost information
167
-------
presented in Tables 54 and 58 for the typical complete
chrome tannery (with wastewater pretreatment) and the
beamhouse/tanhouse facility, respectively, is the average
of the costs associated with two filter press, one
centrifuge, and one vacuum filter systems. This cost
information was collected during visits to four tanneries
utilizing these systems.
5.3 Off-Site Disposal
The typical plants from all six categories of tanneries
which generate potentially hazardous waste hire contractors
to haul and dispose their waste off-site. Although a few
tanneries with wastewater treatment systems dispose
potentially hazardous waste on-site and other tanneries
haul their own waste, these practices are atypical for
all categories in the tanning industry.
The costs of contractor hauling and disposal of the
potentially hazardous waste are based on information
obtained from tanneries. Tannery quoted unit costs, which
are presented in Table 52 , range from $2 per metric ton
for disposal in an open dump to $10 per metric ton for
disposal (from a large complete chrome tannery) in a
state certified hazardous waste disposal site to $31 per
metric ton for disposal (from a small finisher) in a
landfill. The range in disposal costs are due to a variety
of factors, including, distance from the disposal site,
regional location, and the volume of waste generated by
a particular tannery. Adjusted costs are indicated in
Table 52 to:
Provide data where no tannery quoted costs were
available.
. Take into account diseconomies due to small
volumes .
Account for unusual quoted unit costs.
. Account for leachate collection at landfills.
Total costs are the overall hauling and disposal costs
for each type of waste and are the figures used in
subsequent cost estimates. Both tannery-quoted and
adjusted costs for dewatered sludge are shown and the total
cost is the same as the adjusted cost. This is due to
abnormally low tannery-quoted costs.
5.4 Treatment and Disposal Costs
A summary of the cost estimates for three levels of
treatment and disposal technology for a typical plant in
the six categories of tanneries which generate potentially
168
-------
TABLE 52
AMD DISPOSAL COJJTS
typical tannery
Solids
Coapleto chnsse tannery
w/o sludge
Sheepskin tannery
Split tannery
Leather finisher
•etan/fiaisher
Bowaterod Sludoo
Conpleta chrome tannery
with oludgo
•
facility
r
Diipo»l aetnad
Landfill
Landfill with loachato collection
Landfill
Landfill with loachato collection
Dunp (including tr innings and
Landfill with loachato collection
• including trineinga and
shavings
- without triBBiags and shavings
Landfill
Landfill with teachato collection
Certified hazardous waste disposal
facility
Landfill (including trlnaings and
shavings)
Landfill (without trioadngs and
•having*)
Landfill with loachato collection
- including trisnings and shavings
- without trissUnga and shavings
Landfill
Landfill with loachato collection
•Certified hasardous waste disposal
facility
Lined trenches
*r. 19f>
(Wl
OjUMOj
costs
IVI*I
,«bl
ai««>
•«'
Mc.»
,(f)
d^lljrn por
tt wi.iht l-.ii
Adjust^
cost a
I*
ao
a4
M
ad
M
«4
M
M
14
a4
10
14
»•
la
tM>trie ton
nis)
1 Total
costs
10
14
ao
>4
a
14
a4
19
44
10
ao
14
34
10
14
14
ia
CCS Engineer*
(a) Average of 11 tanneries.
(M Average of two aplit tannerios and ono complete
(e> Average of two finishers.
Average of throe complete chrone tanneries.
lol
conplote chrone
ono boaadwuso/tanhouso
tannery.
ise facility.
169
-------
hazardous waste is presented in Tables 53 through 59 .
The cost items shown in these tables include land, total
capital investment, annual capital cost, operation,
maintenance, energy and power,, contract services, total
annual cost, and total treatment"and disposal cost per
unit of product and of potentialJy, hazardous waste.
At the recommendation of the Tanners' Council of
America, the median tannery (with respect to production)
was, .chosen ~as= .the typical plant for each category.- Since
the .production of -the largest plant in a category is
over-1001time* tha't of a small plant, the median is chosen
as thevbest>estimate of a typical operation.
All typical plants are located In urban areas,.
preorcrainantly^ Regions I, II,
III, IV) and utilize contract services for solid' waste
haul|ng and disposal-; All of the typical plants are 50
years* old with the exception of the beamhouse/tanhouse
facility which is 15 years old.-
As shown, the total annual, cost- for Level I and LeveL
III is the same for "a typical complete chrome tannery without
primary and/or secondary was^ewavter:>treatment. Although
the cost per;metric ton of waste is higher for Level III,
due to higher costs for disposal in a landfill with leachate
collection, phe total cost,is the same: siiice Level III
assumes that trimmings and*" shavings': are "So" Id 'as a by-product*
whereas Level' I calls for landfilling of this waste.
For a complete chrome tannery1 with primary and/or
secondary waertewater treatment,•* the* total- fixed cost is
due entirely':to sludge dewatering... Sltidgcl,:dewatering
accounts for approximate!^--90 percent: of^idhe increase in the
total*; annual^cost for complete chrome1 tanneries with"
primary and/pr secondary wastewater treatment relative to •
complete chrome tanneries" without waXtetfatelr.'1 treatment
facilities. a,ffhe other 10 percent of the- increase in costs
is the result of sludge disposal charges.
•In the sheepskin tannery category, thV cost of Level
III technology is slightly higher than Levels I and.IX due
to €S^1c&ffir^n€ tttt leiacti&e'coi't&tion be provided
in Level III disposal technology. The cost per ton of waste
disposed for all .three level-s, iSt-approximately twice that-.
for complete chrome tannery without primary^ ahd^br secondary
wastewater treatment. This variation'-in cost per-tew arises
because substantially different <^ah£iVies ovf' waste are
generated by these two types of tanneries.
Two different Level III treatment and disposal
technologies are shown for split tanneries, one of which is
substantially more expensive than Level I and one which is
slightly less expensive. The cost shown for Level I is based
on open dumping of all the potentially hazardous waste
generated. The more expensive Level III technology
(Alternative 1) is based on disposal of the same quantity
170
-------
TABLE 53
TREATMENT MID DISPOSAL COSTS
TYPICAL CXJMPLfcTK CHROME TANNKRY
Iwithout primary and/or secondary wastewater t
Typical Plant
Characteristics
Annual Production
(1974)
260.000 equivalent
. hides/year
Urban.
gion I
factoring
tanning
V ft leather
finishing
Potentially
Identification of Hasardous
Mastestream(s) Constituent*
Trimmings t shavings Or
Unfinished leather
trtimings Cr.Pb
Buffing dust Cr.Pb
Finished leather
trim Cr.Pb
Finishing residues Cr.Pb,In
mastewater
iiings Cr.Pb
sludge Cr.Pb.Cu
Physical
•olid
•olid
•olid
•olid
•olid
Liquid
for
itmont/Dis-
1 (Met/dry
1000
1.240/S40
114/100
If/at
XIO/IOO
ISO/45
3M/M
2.TOO/300
treatment/Disposal
Costs/Levels
Annual contract haul-
ing t disposal
charges
Average treatment i
disposal cost
• per unit of
production
($/1000 hides)
• per metric ton
of waste*
Dollars (Deo. 1*731
13.000
4«
10
10,
11.
30
14
Description of Treatment/Disposal Technology i
Level I Off-site landfill
Level II Trimmings and shavings soldi other waste to off-site
landfill
Level III Trimmings and shavings soldi other waste t* off-site
landfill with leaehate collection
Sourcei SCS Engineers
• On a wet weight basis.
171
-------
TABLE 54
TYPICAL COMPLETE
(with primary aad/or secondary <
Production
11074i
Typical Plant
Characteristic*
140.000 equivalent
bides/year
I or V • leather
•touting
for
ification of
Tcantsl
Potentially
bttuenta'
Trinnings * shavings Cr
Unfinished leather
trimmings Cr.Pb
Buffing dust Cr.Pb
rinishsd leather
trim Cr.Pb
Finishing residues Cr.Pb.Sn
H«T»0f£dJ4jdJ|f^f}o>
•ings Cr.Pb
sludge Cr,Pb.Cu
1, MO/MO
IM/100
•olid
•olM
SM/MO
aso/«s
JM/M
10.000/1.400
Ttsntnent/Pisposal
Costs
total Pined
1 Costs
Capital Coats
- atiog
Services
Total Annualiced
Average treatment •
disposal cent
- par unit of
protection
. 19/1000 hides)
- per metric ton
of waste*
00.400
10.000
S.OOO
1.400
31.400
119.155
4S1
ST
00.400 00.400
10.OOO 10.000 10.000
•ttOOO ft •> 000 VdjOOO
1.400 1.400 1.400
4S.SOO 4S.100 _>Mgf
nniaY Dims UI.MI
peacriptioa of Treat
Level I Off-site landfill
level II Triasiings and shavings soldi other mttaa linoYMding
detMtcred •ludgnl to off-site certified hasardbos
waste disposal facility
level III Alt. It Sane as Level II
Alt. li Tristtings and shavings kOld as a by-productt
other Mastos to off«site landfill with' leacbate
collection
Sourcei SCS Rnginoers
• On a wet weight basis.
172
-------
TABLE 55
RBATMENT AND DISPOSAL COSTS
TYPICAL SHEEPSKIN TAHNBRV
Typical Plant
Characteristics
Annual Production
(1974)
200.000 equivalent
hides/year
Location
Manufacturing
Urban, Re* Sheepskin
gion I or II tanning
Identification off
•astestreaasU)
Chrome fleshings
Unfinished leather
trissiings
tuffing dust
Mastewater
lings
treatment/Disposal
Costs/Levels
Annual contract haul-
ing * disposal
charges 6.700
Average treatment ft
disposal cost
• per unit of
production
It/1000 hides) 34
- per metric ton
of waste* 20
nt for
Treatswnt/Dis-
posal (wet/dry
Hasardous
Constituents
Cr
Cr.Cu.Pb
Cr.Pb.Cu.Zn
Cr.cu
Level I
Physical
Pom
Slurry
Solid
Solid
Solid
Dollars IDec.
bevel ii
kg per 1000
hides)
1,200/300
170/140
S4VSO
2)0/50
1>7J)
Level HI
•.700
94
29
t.100
40
14
ription of Treatment/Disposal Technologyi
Level I Off-site landfill
Level II Off-site landfill
Level III Off-site landfill with leachate collection
Sourcet. SC8 Engineers
• On a wet weight basis.
173
-------
TABLE 56
TYPICAL SPLIT
II Plant
risties
Production
g«74)
Location
ing
400.000 equivalent Urban. Be-
hides/year ffion X
••tanning cattle
hid* splits
Sdiantification of
Mastestreaats)
ially
mis
tituents
Physical
YriBBihgs, splits
.• shavings
Unfinished leather
. trinnings
Buffing dust
screenings
f& jatstent/Diaposal
.. Cbsts/tevels
il contract haul-
ing • disposal
treataent «
disposal cost
- per unit of
production
(1/1000 hides)
- per Metric ton
of waste*
7.
0.200/1.700
Cr.Pb
Cr.Pb
Cr.Pb
•olid
•olid
Dollars -CDi
aio/aoo
aoo/ioo
aa/s
M. 19111
JLii
1,000 40,000 4,100
17
a
9
ao
m
14
11
24
ietion of
Level X Off-site dumping
level XX TrisBlngs 'and 'shavings sold as •
watts off-site landfill
1 XXX Alt. li Off-site landfill with leachate collection
Alt. at TrinaUngs and ahavings sold as a by-product}
other wastes to off-site landfill with leachate
collection
Sources SC8 Bngineera
• On a wet weight basis.
174
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TABLE 57
TREATMENT AND DISPOSAL COSTS
TYPICAL LEATHER FINISHER
Typical Plant
Characteristics
Annual Production
(19741
225,000 equivalent
hides/year
Location
Manufacturing
Process
Urban, Re- Leather
gion X or XI finishing
Mount for
Treatmnt/Dis-
Xdentification of
Mastestream(s)
Buffing dust
Finishing residues
Treatment/Disposal
Coats/Levels
Annual contract haul-
ing & disposal
charges
Average treatment 4
disposal cost
- per unit of
production
($/1000 hides)
- per metric ton
of waste*
Potentially
Hazardous
Constituents
Cr.Pb
Cr,Zn,Pb
Level I
Physical
Pom
Solid
Liquid
Dollars (Dee.
Level II
posal (wet/dry
kg per 1000
hides)
11/10
1SO/SS
1973)
Level III
1.100
1,100
1,SOO
4.90
31
4.90
31
€.60
41
Description of Treatment/Disposal Technology!
Level I Off-site landfill
Level XX Off-site landfill
Level XXX Off-site certified hazardous waste disposal facility
Sourcei SCS Engineers
• On a wet weight basis.
175
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TAPL«! 58
TREATMENT AND DISPOSAL COSTS
TYPICAL BEAMHOUSE/TANHOUSB FACILITY
Annual Production
(1974)
.Location
Manufacturing
Process
Typical Plant
Characteristics
300,000 equivalent--Mid-'or South- Cattlehide
hides/year western city chrome
tanning
Identification of
WastestreamCs)
Potentially
Hazardous.
Constituents-
Physical
' Form
Amount for
Treatment/Dis-
posal (yet/dry
kg per 1000
hides)
Nastewater sludge Cr.Pb
Sludge cake 10.000/2.400
Treatment/Di sposa 1
•j -Cbsta/LevelS
Of' „/ * "A-* V " '
InvestmenttiCosts
~~
Mrs (Dec. 1973)
Other Vf
Total .Fixed
Annual Costs
Capital Coats
Operating- • '- -•
Maintenance
Energy
Contract Services
Total AnriUaJUized
Average treatment ft
disposal cost
- per unit of
production
($/1000 hides)
- per metric ton
of waste*
Level I
4.000
300 ; OOP
3O4;OOO
•i 'Level 'II-
4.0.00
300. 000 *
304 ,-000
Level
Alt. 1
TTTOp
300.000
304', 000
III
Alt. '2
.4.000
300.000
304,000
60., 400
18,000
5.000
2,400
30.000
115,400
390
38
60,400
18,000
5.000
2.400
36.000
121/800
406
41
60.400 '
18.000'-
5.000.
2..4190 :
36.000
406.
41
60,400
18$000
5,000
2,.400
42.000
127,800
426
43
Description of Treatment/Disposal Technology!
.T.i ,.?•.. '
Level I Dewater and disposal in off-site landfill*
.' L . *s i. —
Level II Dewater and dispose in off-site lined,trenches. ,
«3iKa-? •_,j-»a<.,i: •„«..• ?-i-I ,•,-'•-• • - •
Level III Alt. 1: Dewater and dispose in off-site lined trenches
Alt. 2: pewater_Jand_di8pose.in..o£fr8ite landf-ill with.r.
"leachate collection "
Source: SCS Engineers
• wet weight basis.
176
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TABLE 59
TREATMENT AND DISPOSAL COSTS
TYPICAL RETAN/FINISHER
Typical Plant
Characteristics
Annual Production
(1974)
675,000 equivalent
hides/year
Local ion
Region I
or XX
Manufacturing
Process
Leather re-
tanning *
finishing
Amount for
Treatment/Dis-
Zdentification of
Hastestrearn(a >
Trimmings t
shavings
Unfinished leather
trim
Buffing dust
Finished leather
trim
Finishing
i _>sidues
Mastewater
screenings
Treatment/Disposal
Costs/Levels
Annual contract haul-
ing t disposal
charges 12.000
Average treatment t
disposal cost
- per unit of
production
(S/1000 hides) 18
• per metric ton
of waste* 10
Potentially
Hazardous
Constituents
Cr
Cr,Pb
Cr,Pb
Cr,Pb
Cr,Pb,Zn
Cr,Pb
Level Z
Physical
Form
Solid
Solid
Solid
Solid
Liquid
Solid
Dollars (Dec
Level II
posal (wet /dry
kg per 1000
hides)
1,260/540
114/100
27/25
220/200
150/45
40/10
. 1973)
Level III
Alt. 1 Alt. ;
8,000
12
20
17.000
25
14
9,000
13
24
Description of Treatment/Disposal Technology!
Level I Off-site landfill
Level XZ Trimmings and shavings soldi other waste to off-site
landfill
Level ZXX Alt. 1: Off-site landfill with leachate collection
Alt. 2: Trimmings and shavings sold as a by-product;
other waste to off-site landfill with leachate
collection
Sourcei SCS Engineers
* On a wet weight basis.
177
-------
of waste in a landfill with leachate dellection, which will
cost $12 per metric ton more than open dumping. The less
expensive Level III (Alternative 2) costs are based on the
sale of trimmings and shavings arid the disposal of other
potentially hazardous waste. The large difference in the
total cost of these two alternatives arises because blue
trim and shavings represent 90 percent of the waste generated
by a typical split tannery. The cost per ton of waste
actually disposed via Alternative 2 is increased due to the
substantially reduced quantity of waste which must be collected
and disposed.
A typical leather finisher generates less solid waste
than any other category in the industry. Consequently, the
annual contract hauling of the disposal costs for all three
levels of technology are less than for any other category.
However, the cost per metric ton is higher than for
most other categories due to the small volumes of waste
which must be collected and disposed.
Since wastewater treatment sludge is the only potentially
hazardous waste generated by a typical beamhouse/tanhouse
facility, all costs shown are the result of sludge treatment
and disposal. The cost of treatment and disposal for the
most expensive Level III (Alternative 2) is only about 10
percent higher than for Level I. However, since about 90
percent of the total annual cost is the result of sludge
treatment, 'which is the same for all levels of technology,
the percentage increase in total cost to go from Level I
to Level III technology is not very substantial.
A typical retan/finisher generates the same types of
waste in approximately the same quantity as a complete chrome
tannery without primary and/or secondary wastewater
treatment, except that the complete chrome tannery generates
sewer sump sludge. The cost per metric ton for Level II
technology for a typical retan/finisher is twice that for
Level I because the total quantity of potentially hazardous
waste being land disposed in Level II is only approximately
30 percent of that in Level I (due to sale of trimmings and
shavings as part of Level II technology). The more expensive
Level III technology (Alternative 1) reflects disposal of
all potentially hazardous waste, whereas the less expensive
Alternative 2 is based on the sale of trimmings and shavings
as a by-product and disposal of other waste.
To obtain the total cost of each level of treatment
and disposal technology for each category of the tanning
industry, the following equation was used:
Annual cost of Total annual category Annual cost of
technology level = production x technology level
for category Typical plant production for typical plant
178
-------
Using this relationship, Table 60 was developed to
summarize the total costs of treatment and disposal for
each category of tannery and illustrates the differences
in costs discussed above. For complete chrome tanneries
with primary and/or secondary treatment sludge, approximately
90 percent of the total annual treatment and disposal costs
are the result of wastewater treatment sludge. For beamhouse/
tanhouse facilities, 100 percent of the treatment and
disposal costs are the result of wastewater treatment
sludge. As a result, approximately 65 percent of the cost
of treatment and disposal for the total industry for all
three technology levels is a result of wastewater sludge
dewatering and disposal.
For complete chrome tanneries without primary and/or
secondary wastewater treatment sludge, the total annual
treatment and disposal costs for all levels of technology
are substantially higher than for other categories such as
sheepskin, split tanneries, retan/finishers and leather
finishers. This occurs since chrome tanneries produce more
leather and generate more potentially hazardous waste than
the other categories mentioned.
Another important factor effecting the cost of
treatment and disposal technology for the total industry is
the ability of complete chrome tanneries (without primary
sludge), retan/finishers, and split tanneries to sell blue
trim and shavings as a by-product. For these three
categories of tanneries, the cost of treatment and disposal
is less for Level II (with sale) than Level I (without
sale), with the result that the total cost to the industry
of Level I technology is virtually the same as for Level II.
Similarly, the difference in cost between the most and least
expensive Level III technology is primarily a function of
whether blue trim and shavings are sold or land disposed.
Using the distribution of production between the
various categories observed in 1974, the value added in
manufacturing (in December 1973 dollars) during 1974 was
$480 million, and total value of shipments was $1,010
million. Thus, the costs of the three levels of treatment
and disposal technology compared to the value added in
manufacturing and the value of shipments are as follows:
Treatment and Treatment and
disposal cost— disposal cost--
percent of value percent of value
Technology level added of shipments
I 0.67 0.32
II 0.68 0.32
III (least costly
alternatives) 0.70 0.33
III (most costly
alternatives) 0.81 0.38
179
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TABLE 60
ANNUAL TREATMENT AND DISPOSAL COSTS
(Dec. 1973 dollars)
Tannery
Category
Chrome w/
sludge
Chrome w/o
sludge
Sheepskin
Split
Leather
finisher
Beamhouse/
Tanhouse
Facility
Retan/
Finisher
Total
Level I
1, 524 f 000
675,000
84,000
60,000
27,000
812,000
37,000
3,219,000
Level II
1,702,000
519,000
84,000
31,000
27,000
854,000
25,000
3,242,000
Level
Least costly
1,629,000
675,000
101,000
37,000
37,000
854,000
28,000
3,361,000
III
Most costly
1,702,000
675,000
101,000
411,000
37,000
896,000
53,000
3,875,000
Source: SCS Engineers
180
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5.5 Variables Effecting Treatment and Disposal Costs
5.5.1 Size. The economies of scale in tanneries are
somewhat limited by the batch process nature of the tanning
operation, thus plants in the tanning industry vary widely
in size from a few thousand equivalent hides per year to
nearly one-half million. This range in production yields
a corresponding range in the quantities of potentially
hazardous waste generated per 1000 equivalent hides. This,
in turn, results in great variations in waste disposal
costs. For example, a small tannery with regular, contracted
hauling spends much more per metric ton of waste than does
a large tannery (the waste is collected under contract
hauling whether or not the container is full). Cost for a
retan/finisher and a leather finisher reveals the cost of
solid waste disposal per metric ton of waste may be three
times greater for plants producing relatively small
quantities of waste than for those producing more typical
quantities. These quantity-related differences were taken
into account (to the extent possible) in developing the
adjusted costs shown earlier in Table 52 .
5.5.2 Processing Operations. Processing operations
also vary greatly from plant to plant within any category
of the tanning industry. These variations depend to a
large extent upon the type of market to which a given
tannery is trying to make its product appear; i.e., a
tannery may intentionally generate more waste than normally
expected in pursuit of the production of high quality
products. No generalizations with respect to the effects
of these variations on treatment and disposal costs are
possible.
5.5.3 Location. Geographic location of tanneries
affects treatment and disposal costs in the sense that costs
are higher for those tanneries located in urban areas than
for those located in more rural settings. In addition,
tanneries in certain areas are able to dispose their waste in
municipal facilities where the cost of operating the
disposal facilities is included in their taxes. In rural
settings, the cost of treatment and disposal is estimated
to be approximately $3 per metric ton less than for a
typical plant. The adjustments made in Table 52 attempt
to account for some of the variations that are found.
If there are no nearby certified hazardous waste
disposal facilities or landfills with leachate collection
systems, a tannery would incur long distance hauling charges
which would increase their disposal cost, or the tannery
would have to establish its own disposal site, either on
the plant property, or at a remote site. Situations which
would require a tannery to haul its waste more than 50
miles to such a site are likely rare and have not been
included in the cost estimates presented.
181
-------
State and local regulations governing potentially
hazardous waste disposal impact on only a very few tanneries.
Thus, they do not have a significant effect on treatment
and disposal costs for the industry.
5.5.4 Method of Dewatering Sludge. The cost of
treatment and disposal of sludges is primarily dependent
upon the type of dewatering system utilized, the
effectiveness of the primary clarification system, and the
quantity of wastewater treated. Capital costs for sludge
treatment installations varies depending upon the type of
system used and the equipment manufacturer. Significant
variations in operating costs result from varying'chemical
usage which depends on the type of dewatering system. The
cost of operating different dewatering systems at four
tanneries varies from approximately $7,000 to $30,000 per
year, depending primarily upon the quantity and types of
chemicals used to aid in the dewatering process. Processes
associated with sludge dewatering may also vary as a
function of the effectiveness of the primary clarifier.
No information is available, however, to quantify the effects
that this might have on the costs presented for the
typical tanneries.
5.6 Sample Cost Calculation
For illustrative purposes, the following computation
of the costs of Levels I, II, and III technology are
presented for a complete chrome tannery.
5.6.1 Level I Technology; sludge dewatering and off-
site landfill
Capital costs. (December 1973 dollars)
Land requirements
Disposal is off-site. Treatment facilities require
approximately 0.08 ha (0.2 ac) of land. It is
assumed based on contractor experience that land
costs are $50,000/ha ($20,000/ac). Land costs are:
0.08 x $50,000 = $4,000
Equipment and installation
Wastes are hauled by a contractor, thus dewatering
equipment is the only equipment to be considered.
Interviews at four tanneries and contact with
equipment suppliers indicated that the average
price of an installed sludge dewatering unit
(the costs of a filter press, centrifuge and vacuum
filter are all taken into account) is $300,000 for
the typical plant.
132
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Interest costs, assumed at 10 percent of the capital
cost of $304,000 for the sludge dewatering system
and the land, is $30,400/year.
Using straight line depreciation for the expected
life of the equipment (10 years for $300,000
equipment), depreciation is $30,000/year.
Operating Costs
Labor
1 man, 20 hours per week, 50 weeks per year,
operating dewatering equipment at $3.60/hr plus
33 percent fringe benefits equals $4,800/year.
Supervision = 10 percent of labor cost (assumed) =
$500
Materials
The cost of materials varies significantly from
plant to plant ($2,000-$30,000) , depending on the
volume of production and the type of dewatering
equipment being utilized. It is estimated, based
on data collected for five tanneries, that the
typical tannery spends $6,700 per year on materials
(mostly chemicals) .
Maintenance = $5,000 per year, based on tannery
information
Insurance and taxes = 2 percent of capital cost =
$6,000
Energy = 60 hp x 8 hr/day x 250 day/yr x 0.746 kW/hp x
$0.02/kWh = $2,400
Contract services (with disposal in an off-site landfill)
= $10/metric ton (see Table 53 ) x 3,160 metric
tons/year = $31,600/year
Total annual costs $ (1973) /year
Capital costs $ 60,400
Operating
Labor $4,800
Supervision 480
Materials 6,700
Insurance and taxes 6,000 18,000
Maintenance 5,000
Energy 2,400
Contract services 31,600
Total annualized $117,400
Average Treatment and Disposal Costs
per unit of production (1000 equivalent hides)
$117,400/yr =
y
. h
260,000 eq. hides/yr
183
-------
jper, .metric .ton. of-waste
» $37
3,160 metric ton/yr
5.6; 2 Level II technology t trimmings' and shavings
' »rtifi<
'sold , all other waste to certified hazardous waste disposal
facility.
Land requirements, equipment* interest, operating,
maintenance,, and. energy costs are all the sane as for Level
Contract .services - $16/metric ton (see Table 52)
x 2,834 metric tons/year - $45,300/vear
Note that the sale of trimmings and shavings - reduces
the quantity of waste. Revenues from the sale of
trimmings and shavings (approximately $0.0i/kg) are
hot included in the calculations.
Total ... annual . costs $(1973) /year
Capital costs $ 60,400
"Operating 18,000
Maintenance . 5,000
Energy 2,400
Contract services ''45^300
Total annuali&ed 9131,100
Average Treatment arid Disposal Costs
per unit of ; production (1000 equivalent hide's)
• -j ,
131.100/yr .
___
.260,000 eq. hides/yr
per metric ton of waste
$131,100/yr . $46
2,834 metric. tons/yr
. 5.6,3... Level III Technology; Alternative 1— same as
Level zz . ' ^-Alternative 2--trimming8 'and shavings sold, other
wastes to -landfill with leachate collection.
Land .Requirements , equipment, interest, operating,
maintenance, rand energy costs are all 'the same as for Level
I.
Contract services = $14/metric ton (see Table 52 )
x 2,834 metric tons/year - $39 /700/year
Revenue from sale of trimmings and shavings is not
included in these calculations.
184
-------
Total annual costs $(1973)/year
Capital costs $ 60,400
Operating 18,000
Maintenance 5,000
Energy 2,400
Contract services 39,700
Total annualized $125,500
Average Treatment and Disposal Costs
per unit of production (1000 equivalent hides)
$125,500/yr = $482
260,000 eq. hides/yr
per metric ton of waste
$125,500/yr = $44
2,834 metric tons/yr
185
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SECTION 6.0
REFERENCES
1. U.S. Bureau of the Census. 1972 Census of Manufactures.
Industry series: Tanning, Industrial Leather
Goods; and Shoes. Series MC72(2)-31A.
Washington, D.C., U.S. Government Printing
Office, 1975. 27 p.
2. Personal communication'. E. L. Kilik, Tanners'
Council of America, to SCS Engineers, Inc.,
Reston, Virginia, June 1975 through Feb. 1976.
3. Environmental Protection Agency. Disposal of
Hazardous Wastes. Report to Congress.
Washington, D.C., U.S. Government Printing
Office. 1974.
4. Schaklette, H.T., J.C. Hamilton, J.E. Boernger, and
J. M. Bowles. Elemental composition of surficial
materials in the conterminous United States.
Statistical Studies in Field Geochemistry.
U.S. Geological Survey Professional Paper 574-D.
5. Christensen, H.E., ed. Toxic substances list, 1973
ed. Rockville, U.S. Department of Health,
Education, and Welfare (National Institute for
Occupational Safety and Health). 1973.
6. McKee, J.E. and H.W. Wolf, eds. Water quality criteria.
2nd ed. California State Water Resources
Control Board. 1971.
7. Gleason, M., R.E. Gosselin, H.C. Hodge, P.B. Smith.
Clinical toxicology of commercial products.
3rd ed. Baltimore, The Williams 6 Wilkins Co.
1969.
8. Personal communication. W.L. (Pete) Banks, Industrial
Advisor, Region VII, Environmental Protection
Agency, to SCS Engineers, Inc., Reston, Virginia,
Dec. 1975.
9. National Academy of Sciences. Chromium. Washington,
D.C. 1974.
10. Leather Facts. 1st ed. Peabody, Massachusetts, New
England Tanners Club, 1965. 40 p.
187
Preceding page blank
-------
11. Versar Inc. Assessment of industrial hazardous
waste practices, inorganic chemicals industry.
Environmental Protection Agency Contract No.
68-01-2246. Springfield, Virginia. March 1975.
.12. Versar, Inc. Assessment of industrial hazardous
. waste- practices : storage and primary batteries
industries. Environmental Protection Agency
Report (S«-l02c). Washington, D.C., U.S.
Government Print ing Office. 1975.
13. U.S. Department of Health, Education, and Welfare,
Public Health Service, Consumer 'Protection and
'Environmental Health Services, Environmental
Control Administration. Public health service
.drinking
-------
20. Bertrand, D. and A. deWolf. Le chrome, oligoelement
dynamique pour les vegetaux superieurs. C. R.
Acad. Sci. 26:5616-5617, 1965.
21. Pratt, P.P. Chromium. In Diagnostic Criteria for
Plants and Soils. ~TH.D. Chapman, ed.) Riverside,
University of California Division of Agricultural
Sciences. 1966. pp 136-141.
22. Personal communication. R. M. Lollar, Tanners' Council
of America, to SCS Engineers, Inc., Reston,
Virginia, June 1975 through February 1976.
23. Personal communication. M. Jackson, Particle Data
Laboratories, to SCS Engineers, Inc., Reston,
Virginia, Dec. 1975.
24. Thermal Processing and Land Disposal of Solid Waste
Guidelines. Federal Register, 39 (158): 28334,
Aug. 14, 1974.
25. Battelle Memorial Institute. Final Report; program
for the management of hazardous wastes.
Environmental Protection Agency. Richland,
Washington, D.C., July 1973.
26. SCS Engineers. Draft Final Report, Vol. II, Case Study
Site Reports, Sewage Treatment Solids Disposal by
Subsurface Land Application. Environmental
Protection Agency. Long Beach, California,
December 26, 1975.
27. Fields, T. and A. W. Lindsey, Landfill Disposal of
Hazardous Wastes: A Review of Literature and
Known Approaches. Environmental Protection Agency
Publication SW-165. Washington, D.C., U.S.
Government Printing Office, 1975.
28. Personal communication . J.D. Eye, Tanners' Council!
of America, to SCS Engineers, Inc., Reston,
Virginia, June 1975 through February 1976.
29. Personal communication. T. Fields, Jr., Office of
Solid Waste Management Programs, Environmental
Protection Agency, to SCS Engineers, Inc.,
Reston, Virginia, October 14, 1975.
30. Personal communication. W. Sanjour, Hazardous Waste
Management Division, Office of Solid Waste
Management Programs, Environmental Protection
Agency, to SCS Engineers, Inc., Reston, Virginia,
Jan. 27, 1976.
189
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31. Environmental Protection Agency. Contract Mo.
68-01-3261. July 9, 1975.
190
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SECTION 7.0
ACKNOWLEDGEMENTS
The conduct of this project was accomplished through
the efforts of the staff of SCS Engineers, Inc., Reston,
Virginia, and Long Beach, California. E. T. Conrad directed
the study with day-to-day project management by Gary L.
Mitchell. The Tanners' Council of America provided
significant input and assistance during the project.
The project staff is indebted to the U.S. Environmental
Protection Agency personnel in the Hazardous Waste
Management Division for their continuing interest, advice,
and guidance during the entire term of the study.
Particular thanks go to Allen C. Pearce, Project Officer,
and Timothy Fields, Jr., Acting Program Manager. Thanks
are also due to the management and other staff members of
the Office of Solid Waste Management Programs, Hazardous
Waste Management Division, who reviewed program progress
and assisted with constructive suggestions. It is the
opinion of the SCS staff that this project has been one
of the best examples of EPA/Contractor coordination in
the firm's history.
The project could not have been accomplished without
the cooperation of the owners and managers of the leather
tanning and finishing establishments visited as part of
this project. Their interest in the study and willingness
to provide necessary information greatly assisted in the
acquisition of data.
The Tanners' Council played an important role in the
study. As a major subcontractor, the Tanners' Council
provided much of the basic industry information, including
most of that which is included in the Industry Characterization
section. Additionally, the Tanners' Council assisted in
the selection of tanneries to be visited and elicited the
cooperation of member firms. Special thanks are extended
to Dr. Robert M. Lollar and Eugene L. Kilik of the Tanners'
Council.
Other subcontractors playing important roles in the
project were Dr. J. David Eye and Meryl R. Jackson. Dr.
Eye accompanied project teams on several plant visits and
provided critical review of several phases of the study
and resultant report. Meryl Jackson, the project's air
pollution consultant, visited several tanneries and provided
advice concerning the effects of air pollution control
equipment..
Laboratory analyses were performed by Daylin
Laboratories, Inc., of Los Angeles, California.
Particular thanks to Henry Espoy and Michael Gordon.
1D1
-------
Our appreciation is extended to the other staff
personnel of SCS Engineers, Inc., for their efforts during
this project. Specifically our thanks to:
David R. Bauer
Ronald J. Lofy
Robert D. Morrison
Michael W. McLaughlin
Cindi D. Culkin
Ginny B. Paul
Marcia Saunders
Dixi A. Russo
Thomas A. Winner
192
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SECTION 8.0
GLOSSARY
Back
Bate
Beaming
Bend :
Buffing :
Buffing dust:
Blue :
Coloring :
Dry Milling :
Equivalent :
Hides
A portion of hide formed by cutting the hide
longitudinally along the backbone, then
trimming off head and belly, leaving a bend
and shoulder.
The treatment of hides with enzymes prior to
tanning. Bating removes the lime used in
the hair removal processes and the enzymes
prepare the hide for the tanning solution by
destroying most of the remaining undesirable
constituents in the hide such as hair roots
and pigments.
The traditional name for the processes of flesh
and hair removal from skins and hides to be
tanned into leather. Beaming operations also
include one or more soaking steps to loosen or
dissolve hair.
A sole leather back with the shoulder trimmed
off.
A light sanding operation applied to the grain
or underside of leather and also to splits.
Buffing smooths the grain surface and improves
the nap of the underside of the leather.
Small pieces of leather removed in the buffing
operation. Buffing dust also includes small
particles of abrasive used in the operation
and is of a coarse powder consistency.
The state or condition of hides subsequent to
chrome tanning and prior to retanning. Hides
in this stage of processing are characteristically
blue in color.
The dying of leather to the desired color and
shade.
The rotating of leather in a large wooden drum
with no added chemicals or water. Dry
milling softens the leather.
A statistical term used by the Tanners' Council
of America to relate the production of tanneries
using various types of raw materials. An
193
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Fatliquor
Finishing
Fleshing
Fresh Hide
Grain Side
Head
Hide
Mechanical
Conditioning
equivalent hide is represented by 3.7 m2
(40 ft2) of surface area and is the
average size for a cattlehide.
The agitation of tanned hides in oils or
related fatty substances. Fatliquoring
regulates the softness and pliability of
the leather and also contributes to its
tensile strength.
The application of materials to the grain
surface of leather to provide abrasion
and stain resistance and to enhance color.
Finishes are usually sprayed or rolled
onto the leather followed by drying.
Finishes may be either water or organic
solvent based and normally more than one
finish coat is applied to the leather.
Other operations considered as part of
finishing include plating and embossing.
The mechanical removal of flesh and fatty
substances from the underside of a hide
prior to tanning. In the case of sheepskin
tanning, fleshing is often accomplished
after the tanning process.
Hide that has not been preserved by brining
or salting. Fresh hides are usually
received at tanneries within 24 to 48
hours of slaughter.
The outermost portion of a hide having
the characteristic natural graining
associated with the outer surface of a
hide or skin.
That part of the hide which is cut off
at the flare into the shoulder, i.e., the
hide formerly covering the head of the
animal.
The skin of a relatively large animal,
at least the size of mature cattle.
A generic term representing a number of
mechanical operations used to alter the
physical properties of the leather.
Operations included are staking, dry
milling, and buffing.
194
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Pickle
Plating
Retanning
Shaving
Shoe Leather
Shoulder
Side
The transforming of hides into an acid
environment prior to tanning. The hides
are agitated in a solution of sulfuric
acid and sodium chloride to reduce the
pH of the hides.
The pressing of grain leather to smooth
its surfaces. Plating may also be done
with an embossing plate which imprints
textured effects into the leather surface.
A second tanning process utilizing either
the natural tanning materials (chromium
or vegetable extracts) or synthetic
tanning agents. Retanning imparts
specialized properties to the leather.
1) An abrasive* mechanical action used to
correct errors in splitting and thus yield
a uniformly thick grain side or split.
2) The waste products generated during
the shaving operation. These are essentially
small pieces of the tanned hide, which
are approximately the size of wood
shavings.
This term embraces a variety of leathers.
Included are: (1) Sole Leather* made from
cattlehides and to a small extent from
horsehides and buffalo hides* which comprises
both the heavier grade* used for outer soles
of shoes and the lighter grades and offal
(heads* shoulders* and bellies)* used to a
greater or less extent for heels* insoles*
toecaps* etc.; (2) Upper Leather, made
principally from calfskins* goatskins*
cattlehides* horsehides* and other classes of
animal skins* going into shoe uppers; and (3)
miscellaneous shoe leathers* including welting,
lining stock* tongue stock* facing stock* etc.
That part, of the hide between the neck and the
main body of the hide.
A one-half of a hide produced by cutting the
hide down the backbone. Normally done to
facilitate processing using smaller equipment
than would be required if full hides were
processed.
195
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Skin
Split
Staking
Syntan
Tanning
Tear-Offs
Trimming
The pelt or skin of animals smaller than
mature cattle, e.g., pigskin, sheepskin,
calfskin.
1) The operation of separating a hide
into two layers, a grain side and a flesh
side ("split"). The process is accomplished
on a splitting machine similar to a
horizontal band saw which slices the hide
through its thickness leaving a relatively
uniformly thick outer, or grain side, and
a split of varying thickness.
2) The underside layer of a hide after
splitting. The split has no grain
characteristics and is often used for the
production of suede leather.
The mechanical massaging of leather to
soften it and make it more pliable.
Synthetic tanning materials, generally
used in combination with vegetable,
mineral or formaldehyde tannages. Syntans
are almost exclusively used in retanning
rather than tanning operations.
The process of converting a hide or skin
into leather by soaking it in a tanning
solution made of vegetable extracts, alum,
formaldehyde, or metals such as chromium
or zirconium.
Small pieces of leather, less than half
a skin, which are torn from a skin during
tanning operations.
1) The removal of the ragged edges and
inferior portions of hides and skins either
before or after tanning. Trimming is
normally accomplished by workers using knives,
2) The hide or leather scraps produced
during the trimming operation.
196
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SECTION 9.0
APPENDICES
197
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Appendix A
Alphabetical List of Establishments
in the Leather Tanning and Finishing Industry
A & B Tanning Corp.
101 Belmont Street
Brockton, MA 02401
A.L.M. Corp.
2-18 Mott Street
Newark, NJ 07105
Acme Sponge & Chamois Co., Inc.
855 E. Pine Street
Tarpon Springs, FL 33580
Adams Tanning Corp.
126 South Street
P. O. Box 5115
Newark, NJ 07105
Admiral Leather Corp.
203 Jansen Avenue
Johnstown, NY 12095
Algy Leather Co., Inc.
15 Mill Street
Danvers, MA 01923
Allen Leather, Inc.
62 Foundry
Wakefield, MA 01880
Bona Allen, Inc.
115 E. Main
Buford, GA 30518
Alliance Leather Finishing Co.
4 Union Street
Peabody, MA 01830
Allied "Leather Co.
324 E. Eleventh Street
Wilmington, DE 19899
L. Alperin Co.
17 Hale Street
Haverhill, MA 01830
Wm. Amer Co.
215 Willow Street
Philadelphia, PA 19123
American Lace & Leather
Co., Inc.
P. O. Box 121
Richmond, VA 23201
American Leather Mfg. Co.
2195 Elizabeth Avenue
Rahway, NJ 07065
Amoskeag Leather Finishing,
Inc.
S. Commercial Street
Manchester, NH 03101
Arizona Tanning Co.
P. O. Box 788
Chandler, AZ 85224
Armira Corp.
1113 Maryland Avenue
Sheboygan, WI 53081
Armira Corp.
Highway 18, North
Bolivar, TN 38008
Aztec Leather Corp.
195 McWhorter
Newark, NJ 07105
Preceding page blank
199
-------
B
BTH Tanning Corp.
122 W. 8th Avenue
Glover sville, .NY 12078
Badger State Tanning Corp.
305 N. 25th Street
Milwaukee, HI 53233
Barbour Welting Co., Inc.
932 Nx Montello
Brockton, MA 02403
A . Earth' -Leather Co >
(Div.( of .Caldwell Lace Leather)
New Albany, IN 47150
Beggs & Cobb Corp.
139 Lynnfield
Peabody,i MA 01960
frfi -Son, Inc-.
76 8,i 8th; Street-
Brooklyn, NY 11211
M . Berger-. Trading,
495 Main Street
Gloversville, NY 12078
Berlin Tanning Co., Inc.
235 S. WisGpnsinf
Berlin, WI ' 54923
Besse , Oaborn & Odell , Inc -
Spring Street
Clinton,, ^ME : 04 92-7 -
Bettencourt Tanning Co. , Inc.
340 Merrimack..
Lawrence /,& Sons, Inc.
Williamsport, MD 21795
200-
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Calanpro, Inc.
2466 Van Ness Avenue
P. O. Box 7166
National City, CA 92050
CaIdwe11 Lace Leather Co.
Auburn, KY 42216
California Tanning Co.
1905 Shenandoah Avenue
St. Louis, MO 63104
Calnap Tanning Co.
P. O. Box 2190
Napa, CA 94558
Camden Tanning Corp.
116 Washington
Camden, ME 04843
Carr Leather Co., Inc.
500 Boston
Lynn, MA 01903
Cayadutta Tanning Co., Inc.
98 Harrison
Gloversville, NY 12078
Chestnut Operating Co.
2nd & Chestnut
Reading, PA 19602
Chic Leather Co., Inc.
84 Wingate
Haverhill, MA 01830
Chicago Tanning Co.
1500 Cortland
Chicago, IL 60622
Cincinnati Kid, Inc.
920 West Ninth
Upland, CA 91786
Clark's Leather Splitting Co., Inc.
36 West Street
Gloversville, NY 12078
Coey Tanning Co.
Wartrace, TN 37138
Colonial Tanning Corp.
8-10 Wilson Street
Gloversville, NY 12078
The Colorado Tanning &
Fur Dressing Co.
1787 S. Broadway
Denver, CO 80210
Comet Leather Finishing
Co., Inc.
Fifth Street
Peabody Industrial Park,
MA 01960
Concord Leather & Skins
Corp.
Fifth Street
Peabody Industrial Park,
MA 01960
Conneaut Leather, Inc.
W. Adams
Conneaut, OH 44030
Coronet Leather Finishing,
Corp.
201 Central Street
Georgetown, MA 01830
Corpro Industries
Lubbock, TX 79408
Creese & Cook Co.
33 Water Street
Danvers, MA 01923
Crescent Leather Finishing
Townsend Avenue
Johnstown, NY 12095
Crown Leather Finishing Co,
422 N. Perry
Johnstown, NY 21095
201
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Cudahy Tanning Co.
5043 S. Packard
Cudahy, WI 53110
Cui
4400 Brighton Blvd.
Denver, CO 80202
E. Cuiranings Leather Co., Inc.
10 High Street
Lebanon, NH 03766
The Custom Tannery, Inc.
1170 Martin Avenue
Santa Clara, CA 95050
J. H. Elliott Leather Co.
356 Adams
Newark, NJ 07105
Ellithorp Tanning Co., Inc.
9-19 Grove
Gloversville, NY 12078
Elton Leather Corp.
47 Spring
Gloversville, NY 12078
Embossing Corp. of America
12 Winter Street
Peabody, MA 01960
Damascus Tanning Co.
Box 470
Coudersport, PA 16915
W. Dardano & Sons, Inc.
37 Grand
Canton, MA 02021
Donne11 & Mudge, Inc.
151 Canal
Salem, MA 01970
Drew Tanning of Brockton, Inc.
62 Watson
Brockton, MA 02401
Dudley Leather Co.
244 Broad
Lynn, MA 01901
Eagle Ottawa Leather Co.
200 N. Beechtree Road
Grand Haven, MI 49417
Eastern Tanning Co.
41 Hardy
Peabody, MA 01960
Eberle Tanning Co.
Church Street
Westfield, PA 16950
Fashion Tanning Co., Inc.
6 Van Road
Gloversville, NY 12078
Fashion Tanning Co.
126 W. Fulton
Johnstown, NY 12095
Fermon Tanning Co.
11-27 Walnut
Peabody, MA 01960
Fidelity Leather Mfg.
Co., Inc.
80 Lowell
Peabody, MA 01960
Flagg Tanning Corp.
624 W. Oregon
Milwaukee, WI 53204
Flavorland Industries, Inc,
Hide Processing Division
P. O. Box 190
Sergeant Bluff, IA 51054
Florida Tanning & Sponge
Co., Inc.
S. Walton
Tarpon Spring, FL 33589
J. Flynn & Sons
80 Boston Road
Salem, MA 01970
202
-------
S. B. Foot Tanning Co.
Red Wing, MN 55066
Foster Leather Co.
R-51 Canal
Salem, MA 01970
L. J. Frebel Sons Co., Inc
499 Main
Belleville, NJ 07109
Frielich Leather Corp.
Industrial Park
Haverhill, MA 01830
Frontier Leather Co.
1210 E. Pacific
P. O. Box 502
Sherwood, OR 97140
Frontier Tanning Co.
Box 122 Star Rt.
Anchorage, AK 99502
A. F. Gallun & Sons Corp.
1818 N. Water
Milwaukee, WI 53201
Garden State Tanning
Fleetwood, PA 19522
A. L. Gebhardt Co.
226 N. Water
Milwaukee, WI 53202
Geilich Tanning Co.
491 W. Water
Taunton, MA 02780
General Leather Finishing Co.
32 Varney
Salem, MA 01970
General Split Corp.
5050 S. Second Street
P. O. Box 491
Milwaukee, WI 53201
General Splitting Co.
28 Winter
Peabody, MA 01960
Genesco
Fort Worth, TX 76101
W. Gibb Leather Co.
54th & Grays Avenue
Philadelphia, PA 19143
Gloversville Embossing
Co., Inc.
28-30 E. llth Avenue
Gloversville, NY 12078
Glove City Abrading Co.,
Inc.
3 Harrison
Gloversville, NY 12078
Gloversville Leather Co.,
Inc.
318 W. Fulton
Gloversville, NY 12078
Gnecco & Grilk Tanning
Corp.
80 Foster
Peabody, MA 01960
Golden Wool Co.
3001 Sierra Pine
Los Angeles, CA 90023
O. F Goldsmith Leather Co.
63 Proctor
Salem, MA 01970
Goldstein Leather Co.
New Jersey R. R. Avenue
Newark, NJ 07102
Goliger Leather Co.
5 Hill
Gloversville, NY 12078
Granite State Leather, Inc
Fairmount
Nashua, NH 03060
Great Lakes Tanning Co.
4100 W. Aver Avenue
Milwaukee, WI 53216
'C3
-------
Greene Tanning Corp.
Hilton Hills NH 02852
Win. Greiner Co.
2252 N. Elston Avenue
Chicago, IL 60614
Gunnison Bros., Inc.
Box 166
Girard, PA 16417
Gunther Tanners 6 Master
Taxidermist
3200 Mariposa
Denver, CO 80202
Gutenstein & Co., Inc.
440 Frelinghuysen Avenue
Newark, NJ 07114
Gutman & Co.
1511 Webster Avenue
Chicago, IL 60614
H
H. D. C. Leather Co., Inc,
101 Foster
Peabody, HA 01960
H. L. S. Leather Co., Inc.
122-124 W. 8th Avenue
Gloversville, MY 12078
Hallmark Leather Co., Inc.
20 Walnut
Peabody, HA 01960
Harmony Buffing Co., Inc.
7 1/2 Mason
Box 428
Peabody, HA 01960
Harris & Tipograph, Inc.
725 Broadway
New York, NY 10003
A. Harvey Leather Finishing, Inc.
500-B Kennedy Blvd.
Somerdale, NJ 08083
Henry Leather Co.
150 Main
Peabody, HA 01960
Hermann Oak Leather Co.
4050 N. First
St. Louis, MO 63147
Rickey Leather Co.
Brighau Hill Road
Grafton, HA 01519
Highland Leather Corp.
Box 248
Sebring, FL 33870
Horween Leather Co.
2015 Elston Avenue
Chicago, IL 60614
E. F. Houghton & Co.
303 W. Lehigh Avenue
Philadelphia, PA 19133
Howes Leather Co., Inc.
Curwensville, PA 16833
and Frank, WV 24937
Hoty & Worthen Tanning Corp.
Railroad
Haverhill, HA 01830
Huch Leather Co.
H. Homer
Chicago, IL 60622
Ideal Finishing Co.
55-61 Boston
Salem, MA 01970
Ideal Leather Finishers
92-94 Spring
Gloversville, NY 12078
Independent Leather Mfg.,
Corp.
315-329 S. Main
Gloversville, NY 12078
204
-------
Irving Tanning Co.
Main
Hartland, MA 04943
JEC Tanning Co.
Ill Foster
Peabody, MA 01960
J. B. F. Industries, INc.
41 w. Eleventh Avenue
Gloversville, NY 12078
J. P. Tanning Co.
373 River Road
Haverhill, MA 01830
Jansha Tanning Co.
1355 State Avenue
Marysville, WA 98270
Johnstown Leather, Inc.
Railroad
Johnstown, NY 12095
S. Jonas Leather Mfg., Co.
174 Broadway
Brooklyn, NY 11211
R. Jones & Co., Inc.
5 Burr
Gloversville, NY 12078
Jones & Naudin Leather Corp.
87 S. Main Street
Gloversville. NY 12078
Jonish Leather Mfg., Co.
55 Mercer
New York, NY 10013
Karg Bros.
6-20 E. Fulton
Johnstown, NY 12095
Kirstein Leather Co.
72 Main
Saco, ME 04072
Kroy Tanning Co., Inc.
18 Goodhue
Salem, MA 01970
The Lackawanna Leather Co.
Richard Mine Road
Wharton, NJ 07885
The Lackawanna Leather Co.
California
The Lackawanna Leather Co.
North Carolina
Lackawanna of Omaha
2420 Z Street
Omaha, NB 68107
Lannon Mfg. Co., Inc.
W. Lincoln
Tullahoma, TN 37388
Law Tanning Co.
401 S. 74th Street
Milwaukee, WI 53204
A. C. Lawrence
(Div. of Estech)
25 & Central Avenue
Ashland, KY 41101
& Rt. 128,
Peabody, MA 01960
& Winchester, NH 03270
6 Hazelwood, NC 28738
6 Newport, TN 37821
& S. Paris, ME 04281
Lawrence Leather Finishing
Corp.
15 Union
Lawrence, MA 01840
Leach-Heckel Leather Co.
72 Flint
Salem, MA 01970
Leather Finishers, Inc.
222 Verona Avenue
Newark, NJ 07104
Leather Finishing Corp.
2615 W. Greves
Milwaukee, WI 53233
The Leather Group, Inc.
10 Burr
Gloversville, NY 12078
253
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Leather Line Co.
122 S. Main
Gloversvllle, NY 12078
Leavitt-Berner Tanning Corp.
114 N. Perry
Johnstown, NY 12095
Legallet Tanning Co.
1099 Quesada Avenue
San Francisco, CA 94124
Liberty Dressing, Corp.
Harrison Street
Gloversville, NY 12078
Liberty Rawhide
663 W. Hobble
Chicago, IL 60610
Loewengart 6 Co. * Inc..
Mercersburg, PA 17236
S. Lojko & Sons, Inc.
23 Oak
Peabody, MA 01960
Lomelis Bros. Splitting Co.
Shetland.Industrial Park
Salem, MA 01970
Los Angeles Tanning Co.
4101 Whiteside
Los Angeles, CA 90063
M
Masassee-Block Tanning Co.
1300 4th Street
Berkeley, CA 94710
Maro Leather Company
831 Broadway
Newark, NJ 07104
Marshall Leather Finishing
Co., Inc.
45 Wooster
New York, NY 10013
Masino Leather Co.
41 Hardy
Peabody, MA 01960
Mason Tanning Co., Inc.
4 Water
Salem, MA 01970
Mass Split, Inc.
55 Walnut
Peabody, MA 01960
Master Inc.
287 E. 6th
St. Paul, MN 55101
N. H. Mats Leather Co.,
Inc.
119 Foster
Peabody, MA 01960
McAdoo & Allen, Inc.
S. Hellertown
Quakertown, PA 18951
McLeod Leather 6 Belting
Co., inc.
P. O. Box 2310
910 Scott Avenue
Greensboro, NC 27402
Meeten & Beghardt, Inc.
1775 Egbert Avenue
San Francisco, CA 94124
R. E. Meyer t Sons, Inc.
5009 Grand Avenue
N. Bergen, NJ 07047
Michael*s Finishing Co.
9 Howley
Peabody, MA 01960
Mid-Tenn Tanning Co.
Industrial Parkway
Shelbyville, TN 37160
Middlesboro Tanning Co.
of Del., Inc.
P. O. Box 189
Middlesboro, KY 40965
Middletown Leather Co.,
Inc.
200 Valentine Street
Hackettstown, NJ 07840
206
-------
Midwest Tanning Co.
1200 Davis Avenue
S. Milwaukee, WI 53172
Missouri Belting
1021 S. Grand Blvd.
St. Louis, MO 63104
Moench Tanning Co., Inc.
P. O. Box 389
Gloversville, NY 12078
G. Moser Leather Co.
Silver
New Albany, IN 47150
Mucci Bros , Inc.
605 N. Third
Newark, NJ 07107
Muir & McDonald
100 Levens
Dallas, OR 97338
Murray Bros Tanning Co., Inc.
215 Salem
Woburn, MA 01801
N
National Leather Co.
465 E. 147th Street
Bronx, NY 10455
National Rawhide Mfg. Co.
1464 W. Webster Avenue
Chicago IL 60614
Nelson & Sons, Inc.
625 Humble Avenue
San Antonio, TX 78225
R. Newmann & Co.
300 Observer Highway
Hoboken, NJ 07030
S. Newmann Tannery
91 Golden
Newark, NJ 07103
New Braunfels Leather Co., Inc.
197 S. Seguin Avenue
New Braunfels, TX 78130
207
Newbury Tanning Corp.
12 Federal
Newburyport, MA 01950
N. J. Tanning Co., Inc.
410 Frelinghuysen Avenue
Newark, NJ 07114
Norwich Leather Co.
70 Brookside Avenue
Borckton, MA 02403
Nuco Leather Finishing
Co., Inc.
646 Grove, Rt. 1
Elizabeth, NJ 07200
O
Ocean Leather Corp.
42 Garden Street
Rahway, NJ 07065
Osmo Tanning & Mfg.
(Div. of Ranred Corp)
Box 151
Spartansburg, PA 16434
Page Belting Co.
Commercial
Concord, NH 03301
E. W. Parks Co.
70 Beacon
Worcester, MA 01608
Parsons Tanning Co.
Parsons, WV 26287
Pearse Leather Co., Inc.
7 Kershaw Avenue
Hampton, NH 03842
Peerless Tanning Co.
24 Briggs
Johnstown, NY 12095
Pfister & Vogel Tanning Co,
1531 N. Water Street
Milwaukee, WI 53201
-------
Phenny-Smidt Leather Co.
21 Caller
Peabody, MA 01960
Pierini Tanning & Dyeing Corp.
28 Paris
Rahway, NJ 07105
Pioneer Tanning Co., Inc
3 Tremont Place
Salem, MA 01970
W. B. Place & Co.
368 W. Sumner
Hartford, WI 53027
Plumer Leather Finishing Co.
1678 Leonard
Cleveland, OH 44113
Poetsch & Peterson
325 S. Maple Avenue
San Francisco, CA 94080
Pownal Tanning Co.
N. Pownal, VT 05260
Prime Tanning Co., Inc.
Sullivan
Berwick, MA 03901
Printz Tanning Co., Inc.
1530 Chestnut
Philadelphia, PA 19102
Progressive Leather Co.
16 Fowle
Woburn, MA 01801
Renco Leather Finishing
Co., Inc.
Harris Street
Gloversville, NY 12078
Rex Leather Finishing
Corp.
119 Foster
Peabody, MA 01960
Richard Leather Co., Inc,
9 Webb
Salem, MA 09170
J. J. Riley Co.
228 Salem
Woburn, MA 01801
Risedorph, Inc
14o W. 8th Avenue
Gloversville, NY 12078
Jos. Roller Co., Inc.
500 Chancellor Avenue
Irvington, NJ 07111
A. H. Ross & Son Co.
1229 N. North Branch
Chicago, IL 60622
R. Rueping Leather Co.
96 Doty
Fond du Lac, WI 54935
R. Rulison & Son, Inc.
Charles Street
Johnstown, NY 12095
Rapco Leather Co.
1010 Davis Road
S. Milwaukee, WI 53172
Raser Tanning Co.
757 Prospect Road
Ashtabula, OH 44004
Remis Industries
(Div. of Beggs & Cobb)
22-24 Johnson
Rahway, NJ 07105
Salem Embossing Co.
12 Hanson
Salem, MA 01970
Salem Suede, Inc.
9 Irving
Salem, MA 01970
Salz Leather
1040 River Street
Santa Cruz, CA 95060
20R
-------
Schaffell Tanning Corp.
W. Fulton
Gloversville, NY 12078
Scholze Tanning
3100 St. Elmo Avenue
Chattanooga, TN 37408
H. Schwarz Leather Co., Inc.
Garden PI. 6 River Road
Edgewater, NJ 07020
Seakas Leather Co.
4 Eagan Place
Peabody, MA 01960
Seal Tanning
(Div. of Beggs & Cobb)
Commercial Street
Manchester, NH 03101
Seidel Tanning Corp.
602 W. Oregon
Milwaukee, WI 53204
Seton Leather Co.
849 Broadway
Rahway, NJ 07104
Shawmut Tanning Corp,
45 Walnut
Peabody, MA 01960
Sheepskin Lining Co., Inc.
10 Cayadutta
Gloversville, NY 12078
Sidney Tanning Co.
218 N. Ohio Avenue
Sidney, OH 45365
Sierra Pine Tanning
3001 Sierra Pine Avenue
Los Angeles, CA 90023
Simco Leather Corp.
99 Pleasant Avenue
Johnstown, NY 12095
Sirois Bros., Inc.
73 Lowell
Peabody, MA 01960
Slip-Not Belting Corp.
432 E. Main
Kingsport, TN 37662
Spanish-American Skin Co.
11-13 Cayadutta
Gloversville, NY 12078
Stahlbrand Leather Co.
Rfd. 3
River Road
Bow, NH 03301
Star Leather
6-8 Division
Gloversville, NY 12078
Strauss Tanning Co., Inc.
145 Lowell
Peabody, MA 01960
Suncook Tanning Corp.
Pittsfield, NH 03263
Sunnyside Tannery
12687 S. E. Sunnyside Road
Clackamas, OR 97015
Superior Hat Leather Co.
119 Foster
Peabody, MA 01960
Sure-Tan, Inc.
1470 W. Webster
Chicago, IL 60614
C. Swartzburg Leather Co.
150 Main
Peabody, MA 01960
Sweet Home Tanning Co.
P. O. Box 454
Sweet Home, OR 97366
G. Swoboda & Son, Inc.
1027 N. Bodine
Philadelphia, PA 19123
209
-------
Tanners Degreasing Co., Inc.
325 Montvale Avenue
Woburn, MA 01801
Tanzer Leather Co.
4 Union
Peabody, MA 01960
Tennessee Tanning Co., Inc
915 Atlantic
Tullahoma, TN 37388
Thiele Tanning Co.
123 N. 27th
Milwaukee, WI 53208
Thru-Blu, Inc.
501 Maiden
S. St.Paul, MN 55075
Travel Leather Co., Inc.
42 Walnut
Peabody, MA 01960
Twin City Leather Co., Inc,
River Road
Gloversville, NY 12078
U
Uber Tanning Company
Owatonna, MN 55060
United Rawhide Mfg. Co.
1644 N. Ada
Chicago, IL 60622
United Tanners, Inc,
9 Orchard Street
Dover, NH 03820
V
Vernon Leather Co., Inc
2890 Sierra Pine Avenue
Los Angeles, CA 90023
Victory Tanning Corp.
123 Upton
Peabody, MA 01960
Virginia Oak Tannery, Inc,
Box 511
Luray, VA 22835
Volunteer Leather Co.
Kefauver Drive
Milan, TN 38258
W
Walnut Finishing Co.
57 Grove
Salem, MA 01970
Waterboro Co.
Depot Street
Waterboro, ME 04087
Weil & Eisendrath Co.
2221 Elston Avenue
Chicago, IL 60614
Weldon Leather Co.
Benicia Industrial Park
P. O. Box 583
Benicia, CA 94510
Wells Tanning Inc.
633 W. Center Street
N. Salt Lake, UT 84054
Western Leather Products
Corp.
904 E. Pearson
Milwaukee, WI 53202
Western Tanning Co.
P. O. Box 44
Delta, CO 81416
White Eagle Rawhide Mfg.
Co.
1652 N. Throop
Chicago, II 60622
Whitehall Leather Co.
Lake
Whitehall, MI 49461
210
-------
R. S. Widen Co.
Ashton Avenue
N. Adams, MA 01247
Wilmington Enameling Co.
P. O. Box 66
Wilmington, DE 19899
Wilton Tanning Co.
Box 55, Rt. 2
E. Wilton, ME 04234
Wisconsin Leather Co.
1830 S. Third Street
Milwaukee, WI 53204
Woburn Degreasing Co.
134 Bedford Road
Woburn, MA 01801
Woverine World Wide Co.
9341 Courtland Drive
Rockford, MI 49341
& 501 Musser
Muscantine, IA 52761
Wood & Hyde Leather Co.
69 Wood
Gloversville, NY 12078
Wyaocki Taxidermy & Leather
2451 N.W. 58th Street
Seattle, WA 98107
C. E. Zimmerman & Co.
2756 Toulouse
New Orleans, LA 70119
211
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Appendix B
Outline of Procedures for Field Visits/
Sample Collection, and Sample Analysis'
Development of Field Manual. Early in the project,
a field manual was developed for use by the project teams
visiting tanneries. The purpose of the manual was to
provide general direction to field teams prior to, during,
and after their plant visits. It contained general
instructions, data collection forms, and sample analysis
forms . This material ensured that the field engineers
collected complete information and enabled presentation
of the information in a uniform manner.
A plant visit outline was presented in the manual.
It listed the general steps to be followed by field teams
before, during, and after a plant visit. The outline
ensured that all field teams followed the same general
procedures in arranging for their visits and that all
necessary coordination between SCS, its subcontractors,
and EPA had been accomplished. The plant visit outline
included the following steps:
1. Group the selected plants geographically to
reduce travel time and costs.
2. Telephone the tanneries to reintroduce the project
(they have already been contacted by TCA), arrange
for a convenient visit date, assign a plant code
number. Coordinate with TCA when problems arise;
e.g., an important tannery is reluctant to cooperate.
3. Develop travel itineraries and advise EPA and
TCA of travel plans as soon as possible. Send
copies of itineraries to Dr. Eye and Meryl
Jackson when appropriate.
4. Send a visit confirmation letter or telephone
the tannery a few days prior to the planned
visit to remind them of the planned visit.
5. Complete the plant visit. Fill out the plant
visit data collection form as well as sampling
and analysis forms during the visit and dictate
supplementary memorandum for material that does
not lend itself to notation on the forms.
Complete the disposal site visit form when a
disposal site is visited.
2;.3 Preceding page blank
-------
6. Send a letter to each plant visited thanking them
for their cooperation in the project and
transmitting a typed copy of the plant visit data
form to the plant for their comments, corrections,
and for their general information. Also send
copies to the EPA Project Officer and TCA.
7. If samples were obtained at the plant, send copies
of the sample analyses to the plant upon receipt
from the analytical laboratory.
During each plant visit, the plant visit data collection
form was completed. Information areas included in the
data form are as follows:
1. Identification—plant and field team.
2. Processing
Production information
General processing block diagram
Specifics on the various types of operations
conducted at the plant. Space was provided
for detailed block diagrams in order to
show movement of hides and sources of process
solid wastes.
Information concerning by-product handling,
including a by-product sale summary tabulation.
3. Waste material
A sketch of wastewater pretreatment or treatment
facilities, plus methods used by the plant
to handle wastewater sludges.
Information concerning air pollution control
devices.
A listing of chemical containers coming into the
plant by chemical type, container size, number
received per month, and method of disposal.
A lengthy section concerning solid waste
handling and disposal. It included the
names and addresses of contract services,
storage and handling equipment within the
plant, energy consumption for solid waste
handling, labor costs, and equipment and
land costs for on-site treatment and disposal.
A sampling summary table.
A process solid waste summary table (these
latter two tables provided a ready reference
to the types and quantities of solid waste
produced within the plant and information
concerning the samples collected).
71 4
-------
A similar form was developed for the collection of
information at disposal sites accepting tannery solid
wastes. This form includes the following:
Identification information
Description of the disposal site
The number of tanneries served by the disposal
site
. The number and type of equipment used
General operating procedures
Number of workers
Measures used for environmental pollution control
Problems and suggestions as to how disposal
operations could be improved
Sampling Instructions. Particular emphasis was placed
on providing complete instruction for sampling tannery
wastes. By following these instructions, the project could
be assured that the samples would be representative of
tannery wastes within the limitations of the sampling
program and that the samples would have a minimum of
contamination and degradation during storage and shipment
to the laboratory. Separate sections of the sampling
instruction were devoted to:
Sampling equipment and materials
Sampling procedures
Packing and shipment of samples
Pages from the field engineer's manual concerning
sampling instructions and the sampling and analysis data
form are included for the benefit of the reader.
215
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SCS ENGINEERS
SAMPLING INSTRUCTIONS
In t roduct i on
The purpose of the field sampling program is to obtain
representative solid waste samples from each of the leather
tanning and/or finishing plants visited. The accuracy and
care taken during the sampling cannot be overemphasized—•
the accuracy of the analyses depend to a large extent on
the degree to which the sample is representative of the
whole from which it is taken. Refer to Table 1, Preliminary
Sampling Handling Summary, for examples of sample sources
and handling procedures.
Sampling Equipment and Materials
The following materials will be required by the field
sampling team.
1. One copy of "SCS Field Manual"
2. Styrofoam-lined corrugated shipping cartons and
sufficient blue ice for shipping samples requiring
refrigeration. The blue ice should be frozen
prior to obtaining the samples.
3. Adequate supply of glass, one liter wide-mouth
bottles and lids.
4. pH paper (wide range and 7-10 and 10-13 ranges)
to determine the approximate pH of the samples
taken.
5. Adhesive mailing labels and black waterproof marking
pen
6. Two rolls of fiber packing (strapping) tape
7. Notebooks for field notes and calculations
8. Supply of sampling and analysis data forms and
sample inventory forms
9. Some type of rubber footwear or heavy boots
10. Half gallon plastic pitcher for taking sludge
samples
216
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TABLE 1
PRELIMINARY SAMPLING SUMMARY
Sample Source
Location/Operation
Type of Sample
Preservation
Analyses to be Conducted
Hide cellar
Floor sweepings & trimmings
4°C for fresh hides
only, otherwise none
Metals, Pesticides, and Phenols
Beamhouse
Fleshings
Fresh hides
Salted hides
Limed (unhalred) hides
Hair removal
Hair-save residue
Hair-pulp residue
Trimmings
Fresh hides
Brined or salted hides
Limed (unhalred} hides
Floor sweepings
4°C
None
4°C 1f more than 48 hrs.
In transit to lab
4°C
4°C
None
4°C 1f more than 48 hrs.
In transit to lab
None
Metals and Pesticides
Metals and Pesticides
Metals. Pesticides and Sulfides
Metals, Pesticides and Sulfides
Metals, Pesticides and Sulfides
Metals and Pesticides
Metals and Pesticides
Metals, Pesticides and Sulfides
Metals, Phenols, and Pesticides
Tanhouse
Tanning residue
None
Metals, Phenols. Cyanides,
Sulfides. and Pesticides
Splits and shavings
None
Metals
-------
TABLE I (Continued)
PREimiNMY SWUNG SUWRY
Sample Source
Location/Operation Type of Sample
Floor sweepings
Retan, color. Residues
fatliquor
Floor sweepings
KJ
oo Finishing F1nsh1ng residues
Buffer dust
Air pollution filters
Floor sweepings
Other Screenings
Treatment plant sludges
Incinerator residue
Preservitlon
None
None
None
None
Hone
None
None
None
None
None
Analyses to be Conducted
Metals, Phenols, and Pesticides
Metals, Phenols, Sul fides, and
Pesticides
Metals and Phenols
Metals, Phenols. Acrylates.
Cyanides, and Sul fides
Metals, Phenols, and Acrylates
Metals, Phenols, and Acrylates
Metals and Phenols
Metals. Phenols. Sul fides, and
Pesticides
Metals. Phenols, Sul fides.
Cyanides, Pesticides, Acrylates
Metals
Source: SCS Engineers
-------
11. Garden trowel or similar small scoop
12. Rubber gloves
13. Knife or scissors
14. Coveralls, lab coat, etc.—optional
Sampling Procedure
1. Mark carefully on a gummed label, affixed to the outside
of each sample bottle, the appropriate identifying codes,
dates and so forth using a black, waterproof marking
pen (see Figure 1).
2. Assign a different sample identifier to each sample
taken at each plant. Sample identifiers are numbers
beginning with 1 which identify samples and indicate
the total number collected at the plant. The first
sample taken at a plant will be given sample identifier
1, and so forth. In the case of composited samples,
the identifier is associated with the sample container
which may contain two or more portions which make up
the sample.
2. Utilizing the trowel or pitcher, whichever is appropriate.
fill the sample container to approximately 80 percent
of total volume. Cap the bottle tightly. Avoid
spilling the sample material on the outside of the
containers to help minimize odor during sample
shipment.
3. Measure pH of sample
4. Complete two copies of Sampling and Analysis Data Form,
Exhibit A, and one copy of Sample Inventory Form, Exhibit
B.
5. Samples of fleshings or trimmings from fresh hides and
samples with a pH less than 12 which are to be analyzed
for sulfides should be stored and shipped at 3 to 4
degrees C. All other samples may be stored and shipped
at room temperature.
Packing and Shipment of Samples
All samples must be packed in corrugated boxes with adequate
padding material to avoid breakage. Plenty of crumpled
newspaper or other packing material will be placed below,
above, and around each sample bottle. Tops of the bottles
should be in the same direction.
219
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220
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EXHIBIT A
SCS ENGINEERS
LEATHER TANNING AND FINISHING
SAMPLING AND ANALYSIS DATA FORM
(to be sent with each sample)
Plant Code
Sample Identifier
Name of Sampler
Date Sampled
Type of hide: cattle
pig
other
sheep _
buffalo
Source of hide (be specific): domestic
Type of hide used: 1. fresh
Sample location
Type of sample: 1. Hair - save residue
foreign
brined
tanned
2. summer
salted
winter
(check)
2. Pulped hair residue
3. Fleshings
4. Trimmings
7. Treatment plant
sludge
5. Splits and shavings
6. -Tanning sludge
8. Buffer dust
9. Air pollution control
device
10. Screenings
11. Floor sweepings
12. Other
Refrigerated during shipment (circle one): Yes No Sample pH
Appearance: Color . Stratification __
Other
Other remarks:
Plant Code
Sample Identifier
Date received:
(cut here)
Receipt of Sample
(to be completed by laboratory • and returned to SCS)
Condition: Broken container
Box open
Sample temperature
Odor
Hold
Appearance: Color
Other
Other remarks:
Stratification
221
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Sampling and Analysis Data Form Plant Code
Page 2 Sample Identifier
Laboratory Results
(sampler must Indicate analyses To be performed)
Analyses to be
Conducted Parameter Results tops)
Wet BasisDry Basis
All Pesticides
Aldrln
Dieldrin •; HZZZZ
________________ Endrln _ _•'
Heptachlor • ~ • ___
Heptachlor Epoxide " '
DDT (Mixed Isomers) HZZI "
p.p-DDE
P. P-TDE
Methoxychlor __
Chlordane (alpha) __, '"'
Toxaphene _________ -
Strobane __ __
Llndane (gamma BHC) . '
Mlrex • ZZUZZ
Hexachlorophene " ~_' _
Hexachlorobenzene 2"
Dacthal . ___I________
Perthane ________ __——
Polychlorinated Biphenyls .
All Metals (by AA)
Cd
Cr
pb
"9
Be
; Zr •;- • HIZII
Phenol s __ • • ._
Cyanides ___ ~
; Sul fides _' -'•
Methyl aery late ZHHZH '
Ethyl acrylate _ '""
Acrylic acid __________ — — —
Moisture . _ '______
Emission Spec Report on Separate Fora
Other (specify)
222
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EXHIBIT B
SCS ENGINEERS
LEATHER TANNING AND FINISHING
SAMPLE INVENTORY FORM
Plant Name
Plant Code Date(s) Visited
Field Team
Type of Sample
Sample (describe process and sampling
Identifier situation) Remarks
223
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Samples requiring refrigeration should be packed, as
described above, in insulated containers. Styrofoam
sheets or an inexpensive strybfoan ice chest packed in the
corrugated box may be used. Don't forget to put the blue
ice in with the refrigerated'samples.
Include one copy of the Sampling and Analysis Data Form
for each sample shipped.
Tape the sample boxes securely with strapping tape. Affix
the mailing .label and mark the box "Fragile" and "This
Side Up" to keep the bottles upright.
Samples should be shipped prepaid to:
Daylin Laboratories
2800 Jewel Avenue
Los Angeles, California -90058
Shipment of refrigerated samples should be made by air unless
plant is within 2 days of Daylin Labs. Refrigerated samples
are to be sent such that they will arirve at Oaylin
Laboratory Monday through Friday-check estimated delivery
time.
Other samples should be shipped as soon as possible by
surface carrier if the samples will arrive within one week,
if not* ship by air. The following carriers are suggestedi
. United Parcel Service (UPS)
. REA
REA Air Express
Emery Air Freight
. Various airlines' air freight - check if
they will deliver
Field personnel should call Mr. Henry Espoy at 213/582-0981
with the following information as soon as possible after
sending the samples:
A. Number of samples and boxes shipped
B. Date and time shipped
C. Carrier used
D. Estimated time of delivery
224
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Laboratory Procedures. Samples were packaged and shipped
by air freight to Daylin Laboratories, Los Angeles, California,
for analysis. Upon receipt at Daylin, the box of samples
was immediately unpacked, the bottom portion of the first
page of each Sample and Analysis Data Form was filled out
by a Daylin technician, cut from the rest of the form, and
mailed back to SCS in order to verify receipt of samples.
The samples were grouped by code number where possible, and
Daylin job tickets were written up for each sample. Master
sample sheets were also prepared at this time and distributed
to the various departments to notify them of their work on
a given sample set.
The samples were first transferred to the main laboratory.
At this point, each individual sample was mixed thoroughly
to ensure homogeneity. Each individual sample was then
divided in sub-samples or portions which were labeled and
distributed to the respective analytical departments. At
least one sub-sample was frozen as a backup sample. Upon
receipt in the individual laboratories, the samples were
preserved by refrigeration or by chemical means, where a
specific analysis required preservation.
These samples were then subjected to a variety of chemical
analyses. The three major types of analytical procedures
used were atomic absorption, gas chromotography, and wet
chemical methods. The procedures used to prepare the samples
and references to the actual analytical procedures are
outlined below.
Metal Analysis by Atomic Absorption.
Sample Preparation. The method used to prepare samples
for the determination of mercury involved drying all solid
samples in a 60oc oven prior to analysis. All liquid samples
were held under refrigeration until analyzed.
The method of choice for the preparation of all other
metal samples was a wet digestion. A representative portion
of the sample is placed in a Griffin Beaker; then 3 mi
of concentrated sulfuric acid, and 10 ml of concentrated
nitric acid are added to the sample. The acid-sample mixture
is then heated on a hot plate until all organic .natter is
decomposed, and sample solution is effected. After digestion,
the sample is cooled, adjusted to a volume of 100 ml and
analyzed.
Sample Analysis. All metal analyses were performed
using the procedures found in Reference 1 with the
exception of zirconium. Appropriate page numbers in
Reference 1 are included for each metal.
-------
. Cadmium, pg 101-102
. Chromium, pg 105-106
. Copper, pg 108-109
. Lead, pg 112-113
. Mercury, pg 134-138
. Beryllium, pg 99-1QO
. Zinc, pg 155-156
. Zirconium, Analytical Method No. 41, Reference 2
Pesticide Residue Analysis by Gas Chromatography. The
procedures used cor the determination of pesticide residues
in the submitted samples are referenced below. Specifically
because of the detailed nature of the procedures, only the
principles of the methods developed by the Pood and Drug
Administration are presented below.3
Bach sample to be analyzed for pesticide residues was
subjected to an extraction and cleanup procedure following.
Sections 212.1 thru 212.17 of the Pesticides Analytical
Manual, Volume 1. Where require!due to the fat content of
the sample, procedures 211.1 thru 211.12a were followed to
partition the residues between petroleum ether and
acetonitrile.
The samples were initially extracted with acetonitrile
by blending at high speed for several minutes. The extraction
mixture was then filtered and the filtrate diluted with
water in a separatory funnel. Ten ml of saturated sodium
chloride solution was also added at this point. The residues
are then extracted into petroleum ether.
The concentrated residue obtained from the evaporation
of the sample was then subjected to cleanup on a Florisil
Column. Where the concentrate appeared to contain an
excessive amount of fatty material, the sample was partitioned
between acetonitrile and petroleum ether to remove excess
fat prior to separation on the Florisil Column. The various
residues were then eluted from the Florisil Column with mixed
petroleum and ethyl ethers. The recovered materials were
concentrated by evaporation, and analyzed by gas Chromatography.
226
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Chemical Methods of Analysis.
Sample Preparation. Upon receipt of the individual
subsamples, portions of the sample were removed for
preservation. When the cyanide, sulfide, or phenol analyses
could not be started upon receipt, the samples were
preserved using the procedures outlined under the methods
chosen.
Sample Analysis. The following procedures, except
for selenium, are taken directly from Standard Methods
for the Examination of Water and Waste Water, 13th Edition,
American Public Health Association, New York, 1971.4
. Moisture—procedure 224G, Method for the
determination of total residue by evaporation
on solid and semi-solid samples.
. Arsenic—procedure 104A, Silver Diethyldithiocarbonate
Method for the determination of arsenic.
. Cyanides—procedure 207, Method for the determination
of cyanide in wastes.
Phenols—procedure 222, Sections A,B, and C for the
determination of phenols in waste.
. Selenium—Cummins, L. M., J. L. Martin and D.D.
Maag. "An Improved Method for Determination of
Selenium in Biological Material," Analytical
Chemistry, 37, 430-31, 1965.
. Hexivalent chromium—procedure 307B, Diphenylcarbazide
cobrimetric method
Sulfides—procedure 228A, Titrimetric (Iodine)
method for the determination of sulfides.
227
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REFERENCES
1. Manual of Methods Cor Chemical Analysis of Water and
Wastes, Environmental Protection Agency, 1974,
EPA 625/6-74-003.
2. Atomic Absorption Analytical Methods, Jarrell-Ash
Division of Fisher Scientific Co., Waltham,
Massachusetts, March 1972.
3. Pesticide Analytical Manual, Volume 1, Methods which
Detect Multiple Residues. U.S. Department of
Health Education, and Welfare, Food and Drug
Administration, revised September 1972.
4. Standard Methods for the Examination of Water and
Wastewater, 13th Ed., American Public Health
Association, New York, 1971.
228
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Appendix C
Private Disposal Sites
Accepting Tannery Waste
EPA
Region
III
Name, City, State
Middlesex Disposal Co.
Billerica, HA
Burt Shaffer
(617) 884-3208
Charles George
Disposal Co.
Tyngsborough, MA
Charlie George
Elam Fox Estate
Oley, PA
Type of Tannery
Waste Accepted Remarks
Chrome
fleshings
All
Buffing dust
sludge
Land
spreading
on
agricultural
crops
F. R. & S. Landfill All
Baumstown, PA
Mr. Peiffer
Christman's Landfill All
Lenhardtsville, PA
Dennis Christxnan
CID Corporation All
Calumet City, IL
Richard Morehouse
Lake Landfill, Inc. All
(Browning-Ferris Ind.)
Northfield, IL
Bill Ketter
Carl Hansen
(312) 498-0863
Certified by
IL EPA to
accept
industrial
waste.
Leachate is
collected 6
recirculated
Northeast Gravel Co.
Rockford, MI
Buffing dust
& dewatered
primary sludge
229
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BPA
Region Name, City, State
Lauer Landfill
Washington County* WX
Type of Tannery
Waste Accepted
All
VZ1
Wheeling Disposal
Service
St. Joseph, HO
Clay" Buntrocfc
(816) 279-0815
Primary
sludge
State
permitted
for industrial
waste
Certified by
State to
accept
tannery waste
(clay-
lined trenches)
i pesticide
containers
(landfill)
XX
American Canyon
Landfill
Vallejo, CA
All
230
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Appendix D
Methodology for Projecting Waste Quantities
on a State, EPA Regional, and National Basis
During the conduct of this study, the following
methodology was used in order to develop estimates of the
quantities of the various types of process solid waste
generated by the tanning industry. Visits were conducted
to 41 tanneries during which information was obtained on
the quantities and the various types of solid waste produced,
and on the daily production at each tannery (in units of
hides per day). Based on the types, quantities, and
composition of the waste produced at the tanneries visited,
the tanning industry was divided into seven categories.
In order to arrive at quantities of solid waste
produced within each category on a state, EPA Regional,
or national basis, solid waste generation factors (kg per
unit of production) were calculated for each tannery
visited, and the resulting values were averaged for each
type of waste generated within each tannery category. For
example, based on the visits to 22 complete chrome
tanneries, it was determined that the average complete
chrome tannery generated 114 (wet)/I00 (dry) kg of
unfinished leather trim per 1000 equivalent hides
processed (see Table 17). Data to permit conversion
from "hides processed" to "equivalent hides processed" was
provided by the Tanners' Council.
In order to determine the quantity of solid waste
currently generated on a state, EPA Regional, or national
basis, each waste generation factor (developed as described
above) was multiplied by the production (in equivalent
hides per year) in each area. The result was expressed
in metric tons per year.
Waste quantity data for tanneries within a particular
category were reported by state, groups of states, EPA
Regions, and groups of EPA Regions in order to insure
confidentiality of tannery production data. In all instances,
individual state quantities were reported where possible
with the exception of situations where EPA Regions would
have to be "split," e.g., reporting New York and then
including New Jersey with another region.
For example, Table 23 reports the waste generated by
sheepskin tanneries in 1974. In EPA Region I, Massachusetts,
and in Region ill, Pennsylvania, were reported individually
because each has more than three sheepskin tanneries. Maine
and New Hampshire were grouped together because New Hampshire
has only two sheepskin tanneries. Similarly, all (both)
states in Region II were grouped together because New
Jersey has only one while New York has 13. Regions were
231
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•grouped together only when absolutely necessary to insure
confidentiality, e.g., EPA Regions XV and VX were
grouped together because Florida has two sheepskin tanneries
and Texas has one.
In some areas of the country, some tannery waste earn
be sold as a by-product whereas the same waste is land
disposed in other areas, e.g., blue trim and shavi
are currently sold in the Midwest, and to a lesser
along the Bast Coast. Thus, state and EPA Regional
generation tables reflect these variations, i.e., they
report only the waste requiring land disposal.
Both total process and potentially hasardoua waste
were calculated using consistent assumptions and
All national totals reflect the sum of individual entries.
Xn order to predict the quantity of each type of waste
which will be generated in 1977 and 1903, estimates were
made of the percent change expected for total production
for each category of tannery and for the effects of air
and water pollution control on the quantities of particular
types of waste. Estimates of the percent change anticipated
by 1977 and 1983 for each type of waste (based on these
three considerations) were then developed as a single
factor, which was multiplied by the quantity produced in
1973 in order to estimate the quantity to be produced
for 1977 and for 1983. A sample calculation is provided
below.
Sample Calculation—Current Annual Solid waste Generation.
Examples Quantity of unfinished leather trim destined for
land disposal in Region XX from complete chrome
tanneries•
Generation factors 114(wet)/100(dry) kg/1000
equivalent hides
Region XX Productions 1,430,000 eq. hides/year
114 (wet)/100(dry) x 1,430,000 • l«3(wet)/143(dry)
metric tons/year
Unfinished leather trim in EPA Region XXs
163 (wet)/143 (dry) metric tons/year (see Table 18)
Sample Calculation—1977 Projection.
Examples Unfinished leather trim from complete chrome
tanneries in Region XX
Factors i air pollution control—no effect
water pollution control—no effect
pr^uction_increaSie—fc 2% (from TCA)
TOTAL Brrm^ri TO .2%
232
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Calculation: 163/143 x 1.062 - 173 (vet)/I52 (dry)
Results 173 (wet)/152 (dry) metric tons/year
(see Table 19).
uo1460
233
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