GUIDANCE DOCUMENT
FOR
EFFLUENT DISCHARGES
FROM THE
AUTO AND OTHER LAUNDRIES
POINT SOURCE CATEGORY
Anne M. Gorsuch
Administrator
Jeffrey Denit, Acting Director
Effluent Guidelines Division
G. Edward Stigall, Chief
Inorganic Chemicals and Service Industries Branch
Elwood E. Martin
David Pepson
Project Officers
February 1982
DRAFT
Effluent Guidelines Division
Office of Water and Waste Management
U*S. Environmental Protection Agency
Washington, D.C. 20*60
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TABLE OF CONTENTS
Page
LIST OF FIGURES v
LIST OF TABLES vii
ACKNOWLEDGEMENTS »
1.0 EXECUTIVE SUMMARY 1
1.1 SUMMARY AND CONCLUSIONS 1
1.2 DISCHARGE GUIDANCE 1
2.0 INTRODUCTION 3
2.1 PURPOSE AND AUTHORITY 3
2.2 OVERVIEW OF THE INDUSTRY 5
2.3 SUMMARY OF METHODOLOGY 5
3.0 DESCRIPTION OF THE INDUSTRY 7
3.1 DEFINITION AND GROWTH TRENDS 7
3.1.1 Power Laundries, Family and
Commercial (SIC 7211) 7
3.1.2 Linen Supply (SIC 7213) 8
3.1.3 Diaper Service (SIC 721<0 8
3.1.4 Coin-Operated Laundries and Dry
Cleaning (SIC 7215) 9
3.1.5 Dry-Cleaning Plants Except Rug
Cleaning (SIC 7216) 9
3.1.6 Carpet and Upholstery Cleaners
(SIC 7217) 9
3.1.7 Industrial Laundries (SIC 7218) 10
3.1.8 Laundry and Garment Services Not
Elsewhere Classified (SIC 7219) 10
3.1.9 Car Washes (SIC 7542) 10
3.2 INDUSTRY PROCESSES 11
3.2.1 Laundering 11
3.2.2 Dry Cleaning 13
3.2.3 Dual Phase Processing 15
3.2.4 Carpet and Upholstery Cleaning 16
3.2.5 Auto Laundry 17
DRAFT
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Table of Contents - continued
Page
4.0 INDUSTRY SUBCATEGORIZATION IS
4.1 FACTORS CONSIDERED FOR SUBCATEGORIZATION IS
4.1.1 General Types of Cleaning Processes
Employed 18
4.1.2 Types of Garments and Flatwork
Articles Cleaned 20
4.1.3 Types of Laundering Chemicals Used 21
4.1.4 Age and Design of Equipment 23
4.1.5 Operating Schedules 23
4.1.6 Geographical Location 25
4.2 GENERAL CONCLUSIONS 25
5.0 WASTEWATER CHARACTERISTICS OF THE AUTO AND
OTHER LAUNDRIES INDUSTRY 26
5.1 WASTEWATER SOURCES AND QUANTITIES 26
5.1.1 Source of Wastewaters 26
5.1.2 Volumes of Wastewater Discharged 28
5.2 WASTEWATER CHARACTERISTICS' 31
5.2.1 Conventional and .Nonconventional
Pollutants 32
5.2.1.1 Industrial Laundries 34
5.2.1.2 Linen Supplies 36
5.2.1.3 Power Laundries, Family and
Commercial ' 39
5.2.1.4 Diaper Services 39
5.2.1.5 Coin-Operated Laundries 41
5.2.1.6 Carpet and Upholstery Cleaners 41
5.2.1.7 Dry-Cleaning Plants 41
5.2.1.8 Car Washes 41
5.2.2 Toxic Pollutants *1
5.2.2.1 Industrial Laundries 50
5.2.2.2 Linen Supplies 53
5.2.2.3 Power Laundries, Family and
Commercial 55
5.2.2.4 Diaper Services 55
5.2.2.5 Coin-Operated Laundries 55
5.2.2.6 Carpet and Upholstery Cleaners 59
5.2.2.7 Dry-Cleaning Plants 59
5.2.2.8 Car Washes 59
3.3 DISCHARGE TYPES 59
11
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Table of Contents - continued
Page
6.0 EXCLUSION OF SUBCATEGORIES FROM REGULATION 66
6.1 POWER LAUNDRIES, FAMILY AND COMMERCIAL 66
6.2 DIAPER SERVICES 66
6.3 COIN-OPERATED LAUNDRIES AND DRY-CLEANING 67
6.4 DRY-CLEANING PLANTS, EXCEPT RUG CLEANING 67
6.5 CARPET AND UPHOLSTERY CLEANING 67
6.6 CAR WASH ESTABLISHMENTS 68
6.7 INDUSTRIAL LAUNDRIES 6&
6.8 LINEN SUPPLY 69
7.0 CONTROL AND TREATMENT TECHNOLOGY 70
7.1 PRETREATMENT TECHNOLOGY 71
7.1.1 Conventional Technology 71
7.1.1.1 Solids Removal 71
7.1.1.2 Free Oil Removal. 73
7.1.1.3 Temperature Control 73
7.1.1.4 Capabilities of Conventional
Technology 73
7.1.2 Incompatible Pollutant Removal - Presently
Applied Technology 73
7.1.2.1 General Treatment Strategy 75
7.1.3 Incompatible Pollutant Removal -
Potentially Applicable Technology 79
7.1.3.1 Gravity Settling. 79
7.1.3.2 Filtration 81
7.1.3.3 Ultrafiltration 81
7.1.3.4 Diatomaceous Earth Filtration 82
7.1.3.5 Electrocoagulation 82
7.1.3.6 Other Technologies 83
7.1.4 Space Availability 83
7.2 TREATMENT FOR DIRECT DISCHARGE 83
7.2.1 Primary Treatment 85
7.2.2 Secondary Treatment 85
7.2.2.1 , Biological Treatment 85
7.2.2.2 Other Technologies 87
7.3 RECYCLE/REUSE TECHNOLOGY 89
7.4 SLUDGE HANDLING AND DISPOSAL 90
7.4.1 Sludge De water ing 90
7.4.1.1 Rotary Vacuum Filters 90
7.4.1.2 Screw Presses 91
7.4.2 Sludge Quantity 91
7.4.3 Disposal Techniques 91
iii
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Table of Contents - continued
Page
8.0 COSTS OF TREATMENT SYSTEMS 93
8.1 CAPITAL AND ANNUAL TREATMENT COSTS
ESTIMATE SUMMARY 93
8:2 COST BASIS 101
S.2.1 Dissolved Air Flotation Treatment Systems 101
8.2.1.1 Capital Cost Estimate 101
8.2.1.2 Annual Treatment Cost Estimates 101
8.2.2 Biological Treatment Systems. 108
8.2.2.1 Trickling Filters 108
8.2.2.1.1 Capital Cost Estimate 108
8.2.2.1.2 Annual Cost Estimate 108
8.2.2.2 Aerobic-Anaerobic Stabilization
Ponds 112
8.2.2.2.1, Capital Cost Estimate 112
8.2.2.2.2 Annual Cost Estimate 112
8.3 ENERGY CONSUMPTION 112
8.4 SLUDGE MANAGEMENT 112
8.5 OTHER.NpNWATEfr.QUAUTY ASPECTS 116
9.0 SELECTION OF APPROPRIATE CONTROL AND TREATMENT
TECHNOLOGY. AND DEVELOPMENT OF PERFORMANCE LEVELS 118
9.1 GUIDANCE FOR PRETREATMENT 118
9.1.1 Technology Basis 118
9.1.2 Pollutants. - US
9.1.3 Statistical Methodology 118
9.2 GUIDANCE FOR DIRECT DISCHARGE 13f
REFERENCES 135
APPENDIX A LAUNDRY WASTEWATER'TREAT ABILITY DATA A-l
APPENDIX B SURVEY OF THE AVAILABILITY OF SPACE FOR B-l
WASTEWATER TREATMENT AT INDUSTRIAL LAUNDRIES
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LIST OF FIGURES
7-1 DAF treatment system for laundry wastewater using recycle flow
pressurization ............................................... 76
8-1 Total capital cost estimates for pretreatment of laundry waste waters
with DAF .................................................. 96
8-2 Total annual cost estimates for pretreatment of. laundry waste waters
with DAF ............................ . ............. .. ... ..... 97
8-3 Total capital cost estimates for direct discharge treatment with DAF
treatment plus a trickling filter .or a stabilization pond ........... 99
8-4 Total annual cost estimates for direct discharge treatment of laundry
wastewaters ................................................ 100
8-5 Annual chemical costs for DAF treatment of laundry wastewaters . 103
8-6 Daily sludge generation rates for DAF treatment of laundry
wastewaters ...............................................
8-7 Annual sludge disposal savings for dewatered sludge versus annual
amortized cost of sludge •dewatering equipment ....... . .......... 106
8-8 Annual sludge disposal costs for DAF treatment of. laundry
wastewaters ................................. ............... 107
8-9 Capital cost for trickling filter treatment of laundry wastewaters . . 110
8-10 Total annual costs for trickling filter treatment of laundry
wastewaters ................................................ Ill
8-11 Capital costs for stabilization pond treatment of laundry
wastewaters ................................................ 113
8-12 Total annual costs for stabilization pond treatment of laundry
wastewaters ................................................
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UST OF TICURIS
9-1 Cumulative distribution of daily concentrations from industrial
laundry treated effluent ...................................... 123
9-2 Cumulative distribution of daily concentrations from industrial
laundry treated effluent ......................................
9-3 Cumulative distribution of daily concentrations from industrial
laundry treated effluent ................. ..... .......... ...... 1 25
9-4 Cumulative distribution of daily concentrations from industrial
laundry treated effluent ..... ..... ............................ 126
9-3 Estimated performance of proposed DAP treatment .............. 130
9-6 Estimated performance of proposed DAP treatment .............. 131
9-7 Estimated performance of proposed DAP treatment ..... ......... 132
9-8 Estimated performance of proposed DAP treatment ..... ......... 133
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LIST OF TABLES
1-1 Discharge Guidance 2
3-1 SIC Segments of the Laundry Industry 7
4-1 General Types of Cleaning Processes Used by Industrial Laundries,
Linen Supplies, and Power Laundries 19
4-2 General Types of Garments and Flatwork Articles Handled by
Industrial Laundries, Linen Supplies, and Power Laundries 20
4-3 Classification of Chemicals Used by Power Laundries, Linen
Supplies, Industrial Laundries, and Diaper Services 22
4-4 General Types of Chemicals Used in Laundering Selected Garments
and Flatwork Articles 24
5-1 Reported Process Wastewater Discharge Rates by Subcategory 29
5-2 Conventional and Nonconventionai Pollutant Concentrations in
Industrial Laundry Wastewaters 35
5-3 Conventional and Nonconventionai Pollutant Concentration in
Domestic Sewage 35
5-4 Variability of Conventional Pollutant Loadings in Wastewater from
One Industrial Laundry 37
5-5 Conventional and Nonconventionai Pollutant Concentrations in Linen
Laundry Wastewaters 38
5-6 Conventional and Nonconventionai Pollutant Concentrations in Power
Laundry Wastewaters 38
vii
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LIST OF TA5LL5 - continued
Page
5-7 Conventional and NonconventionaJ Pollutant Concentrations in
Diaper Laundry Waste waters 40
5-8 Conventional and NonconventionaJ Pollutant Concentrations in Coin-
Operated Laundry Wastewaters 40
5-9 Conventional and Nonconventional Pollutant Concentrations in
Wastewater from One Carpet-Cleaning Plant 42
5-10 Conventional and Nonconventional Pollutant Concentrations .in
Wastewater from One Dry-Cleaning Plant 42
5-11 Conventional and Nonconventional Pollutant Concentrations in
Rollover, Wand, and Tunnel Type Car Wash Wastewaters 43
5-12 Conventional and Nonconventional Pollutant Concentrations in
Tunnel Type Car Wash Raw Wash and Rinse Wastewaters 44
5-13 EPA Toxic Pollutants 45
5-14 Toxic Pollutant Concentrations and Loadings in Industrial
Laundry Wastewaters 51
5-15 Toxic Pollutants in Laundry Water Supplies 52
5-16 Toxic Pollutant Concentrations and Loadings in Linen
Laundry Wastewaters 54
5-17 Toxic Pollutant Concentrations and Loadings in Power Laundry
Wastewaters. 36
5-18 Toxic Pollutant Concentrations and Loadings in Diaper Laundry
Wastewaters 37
5-19 Toxic Pollutant Concentrations and Loadings in Coin-Operated Laundry
Wastewaters 5&
5-20 Toxic Pollutant Concentrations in Wastewater from One Carpet-Cleaning
Plant ~ 60
5-21 Toxic Pollutant Concentrations in Dry-Cleaning Plant Wastewaters. 61
viii
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LIST OF TABLES - continued
Page
5-22 Toxic Pollutant Concentrations and Loadings in Wand Type Car Wash
Raw Wastewaters 62
5-23 Toxic Pollutant Concentrations and Loadings in Rollover Type Car
Wash Raw Wastewaters 63
5-2* Toxic Pollutant Concentrations and Loadings in Tunnel Type Car Wash
Raw Wastewaters . 64
5-25 Number of Direct Dischargers in the Laundry Industry 65
7-1 Estimated Percent of Laundries Having Control Technology 72
7-2 Results of Conventional Treatment System , 74
7-3 Area Requirements for Laundry Wastewater Equalization 77
7-4 Summary of Pollutant Removal Efficiencies at Selected Plants Using
DAF Technology ~ ... 80
7-5 Area Requirements for PCS's 84
7-6 Characterization of Laundry Wastewater After Physical-Chemical
Treatment 86
7-7 Effluent Concentrations for Lagoons Treating Wastewater from Coin-Op
Laundries.. .-. 86
7-8 Performance for Trickling Filters Treating Wastewater from'Coin-Op'
Laundries 88
7-9 Sludge Quantities Resulting from the Physical-Chemical Treatment of
Industrial Laundry Wastewater 92
8-1 Treatment Options for Laundry Wastewaters 94
8-2 Capital and Annual Treatment Cost Estimates and Totals for
Pretreatment of Laundry Wastewaters with DAF 95
8-3 Capital and Annual Cost Estimates and Totals for Treatment of Laundry
Wastewaters for Direct Discharge (with Biological Treatment) 98
i*.
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LIST OF TABLES - continued
Page
Summary of Annual Treatment Cost Estimates for DAF Treatment of
Laundry Wastewater 109
8-5 Annual Electricity Consumption by Pretreatment 115
8-6 Annual Electricity Consumption at Laundries. 115
8-7 Amount of Sludge Generated per Year by Pretreatment 117
9-1 Achievable Performances by D.A.F 120
9-2 Statistical Summary of Treatment Data for Plant Z 120
9-3 Statistical Summary of Treatment Data for Seven Industrial
Laundries. 1.21
9-4 Statistical Summary of Treatment Data for All Industrial
Laundries. 121
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ACKNOWLEDGEMENTS
This technical document was prepared by Jacobs Environmental Division of
Jacobs Engineering Group Inc. of Pasadena, California, under the direction of
Mr. Henry Cruse, Vice President, and Ms. Bonnie Parrott, Project Manager. Major
contributors were Mr. Thomas Schaffer, Mr. Dennis Merklin, Mr. William Ray,
Dr. Ben Edmondson, and Ms. Jane Palmer.
Previous contractors providing substantial support data and draft reports were
Monsanto Research Corporation of Dayton, Ohio, and Colin A. Houston and
Associates Inc. of Mamaroneck, New York.
We would like to express our appreciation to the Institute of Industrial
Launderers, the Textile Rental Services Association of America, the International
Car Wash Association and numerous individual corporations for their cooperation
and assistance in providing, review and comments. The many company and plant
personnel who submitted information and opened their facilities to project members
are greatly appreciated.
xi
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SECTION 1
EXECUTIVE SUMMARY
1.1 SUMMARY AND CONCLUSIONS
To explore possible need for efiluent standards or guidelines, a study of the
Autos and Other Laundries industrial point source category was undertaken. The
industry was divided into the following segments:
o Industrial laundries
o Linen supply
o Power laundries, family and commercial
o Diaper service
o Dry cleaning plants, except rug cleaning
o Carpet and upholstery cleaning
o Coin-operated laundries and dry cleaning
o Laundry and garment services not elsewhere classified (NEC)
o Car wash establishments
Sampling and analysis of discharges from this industry showed that toxic
pollutants, both inorganic and organic, occur in wastewaters from all segments
(except NEC). The amount and toxicity of these pollutants, however, were
considered insignificant in all subcategories except industrial laundries and linen
supply laundries.
The number of facilities in this industry with treatment systems is small.
However, in cases where treatment systems have been installed, dissolved air
flotation (DAF) has been selected as providing the best treatment. DAF effectively
reduces both conventional and toxic pollutants. The use of various alternative
technologies for the removal of pollutants from this industry was considered not
feasible for various technological reasons (see Section 7).
Greater than 99 percent of the laundry industry discharges to publicly owned
treatment works. Only one direct discharger was identified in both the industrial
and linen supply subcategories.
1.2 DISCHARGE GUIDANCE
Achievable performance for new and existing sources is presented in
Table 1-1.
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TABLE 1-1. DISCHARGE GUIDANCE
Pollutant
Chromium
Copper
Lead
Zinc
TSS
BOD
Oil and Grease
Estimated
Long-Term
Average
mg/1
0.18
0.7*
0.93
0.7*
Daily
Variability
Factor(a)
4.0
2.7
3.7
4.4
Achievable
Performance
mg/1
24-hr, max. 30-day avg.
0.74
1.5
3.7
2.9
40
100
20
0.22
0.93
1.7
1.1
20
50
10
(a) Daily variability factor is the ratio of the estimated
95th percentile to the estimated long term average.
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SECTION 2
INTRODUCTION
The purpose of this document is to provide technical data required to develop
NPDE5 permits and pretreatment requirements for the Auto and Other Laundries
industry. For direct disharges, limits should be based on the hazards involved, the
removal efficiency of demonstrated technology, and compliance costs, using this
document for guidance. For pretreatment, the effect of pollutants on the operation
of a publicly owned treatment works (POTW) and the ability of the POTW to
effectively reduce pollutant concentrations must also be considered.
The information in this document is presented in the following manner. The
laundry industry is defined and described in Section 3 and subcategorized for
evaluation purposes into distinct segments in Section 4. Wastewaters resulting from
each of the industry subcategories are characterized in Section 5 in terms of flow,
pollutant concentration and load. Conventional pollutants and 129 toxic pollutants
are considered. The bases for exclusion from regulation are presented in Section 6.
In Section 7 control and treatment technologies, including both in-process and end-
of-pipe controls and alternatives, are discussed in relation to their applicability to
the appropriate subcategories. Capital and operating costs for the treatment
systems discussed in Section 7 are presented in Section 8. Section 9 describes
achievable effluent concentrations for the industry, as well as the bases for the
concentrations.
2.1 PURPOSE AND AUTHORITY
The Federal Water Pollution Control Act Amendments of 1972 established a
comprehensive program to "restore and maintain the chemical, physical, and
biological integrity of the Nation's waters" (Section 101(a)). To implement the Act,
EPA was to issue effluent limitation guidelines, pretreatment standards, and new
source performance standards for industry dischargers.
The Act included a timetable for issuing these guidelines. However, EPA was
unable to meet many of the deadlines and, as a result, in 1976, it was sued by
several environmental groups. In settling this lawsuit, EPA and the plaintiffs
executed a "Settlement Agreement," which was approved by the Court. This
Agreement required EPA to develop a program and adhere to a schedule in
promulgating effluent limitations guidelines, and pretreatment standards for 65
"priority" pollutants and classes of pollutants, for 21 major industries. See Natural
Resources Defense Council, Inc. v. Train, & ERC 2120 (D.D.C. 1976), modified, 12
ERC 1333 (D.D.C. 1979).
Many of the basic elements of this Settlement Agreement program were
incorporated into the Clean Water Act of 1977. Like the agreement, the Act
stressed control of toxic pollutants, including the 65 "priority" pollutants. In
addition, to strengthen the toxic control program, Section 3Q4(e) of the Act
authorizes the Administrator to prescribe "best management practices" (BMPs) to
prevent the release of toxic and hazardous pollutants from plant site runoff, spillage
or leaks, sludge or waste disposal, and drainage from raw material storage
associated with, or ancillary to, the manufacturing or treatment process.
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Under the Act, the EPA program is to set a number of different kinds of
effluent limitations, as follows:
Best Practicable Control Technology (BPT) limitations are generally based on
the average of the best existing performance by plants of various sizes, ages, and
unit processes within the industry or subcategory.
In establishing BPT limitations, EPA balances the total cost of applying the
technology against the effluent reduction benefits achievable. This is a limited
balancing, in that EPA is not required to quantify benefits in monetary terms.
Best Available Technology (BAT) limitations, in general, represent the best
existing performance in the industrial subcategory or category. The Act establishes
BAT as the principal national means of controlling the direct discharge of toxic and
nonconventional pollutants to navigable waters.
In arriving at BAT, the Agency retains considerable discretion in assigning the
weight to be accorded costs. EPA needs only to consider the cost of applying the
technology; no cost/benefit analysis is required.
Best Conventional Pollutant Control Technology (BCT) limitations are based
on the "best conventional pollutant control technology" for discharges of
conventional pollutants from existing sources. Section 304(a)(
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2.2 OVERVIEW OF THE INDUSTRY
The Auto and Other Laundries industry category consists of nine segments
which have been divided by the Standard Industrial Classification (SIC) system. The
segments are:
Power laundries, family and commercial
Linen supply
Diaper service
Coin-operated laundries and dry-cleaning
Dry-cleaning plants, except rug cleaning
Carpet and upholstery cleaning
Industrial laundries
Laundry and garment services not elsewhere classified
Car wash establishments
The above-listed segments consist of over 90,000 operating facilities primarily
engaged in the cleaning (dry or water-wash) of fabric-materials or vehicles.
Wastewaters generated in this industry thus consist of contaminants removed from
the cleaned material and chemicals added during the cleaning process.
2.3 SUMMARY OF METHODOLOGY
Background information on the basic segments of the Auto and Other
Laundries industry was obtained from literature, contacts with the industry and its
trade associations, previous reports and a mail survey of specific segments of the
industry.
Data on wastewater characteristics including sources and disposition of
wastewater, discharge quantities, and physical-chemical characteristics for each of
the eight industrial segments were obtained from NPDES monitoring reports,
municipal sewer district monitoring reports, a mail survey of approximately 250
laundries, trade association studies, and the sampling and analysis programs
conducted by the Agency.
Sampling Program - Sampling and analysis of wastewaters generated by the
Auto and Other Laundries industry was initiated by the Agency and its contractors
in 1975. These early programs concentrated primarily on conventional and
nonconventional pollutants and trace metals.
In 197S a sampling program was begun to determine the presence and
concentrations of the 129 toxic pollutants as defined by the Consent Decree, in
wastewaters from this industry. A total of ftO facilities were sampled for toxic as
well as conventional pollutants. Sampling was conducted using automatic time-
compositing equipment during operating hours at each facility. In most cases
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sampling was for one day only. At facilities where wastewater treatment were in
place, samples of both treatment influent and effluent were taken. One industrial
laundry facility using a DAF treatment system was sampled over a one-month period
to obtain data on the variability of this type of treatment system.
Processing of Data - Data on raw waste characteristics are summarized and
presented in Section 5 in terms of minimum, maximum, median and mean
concentration. Using average flow data, typical pollutant loads in pounds or
kilograms per day are also presented.
Data from plants with wastewater treatment systems in place are presented in
Appendix A and summarized in Section 7. For the development of achievable
performances, a statistical evaluation of these data was conducted and is presented
in Section 9.
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SECTION 3
DESCRIPTION OF THE INDUSTRY
3.1 DEFINITION AND GROWTH TRENDS
The Auto and Other Laundries industry can best be defined and characterized
by considering the various segments of which it is composed. The industry has been
divided into nine segments by the Standard Industrial Classiiication (SIC) system.
These segments, their SIC code numbers, and the approximate number of
establishments included in each segment are shown in Table 3-1.
TABLE 3-1. SIC SEGMENTS OF THE LAUNDRY INDUSTRY
Category title
SIC Approximate number
code number of establishments (1)
Power laudries, family
and commerial
Linen supply
Diaper service
Coin-operated laundries
and dry cleaning
Dry-cleaning plants
except rug cleaning
Carpet and upholstery
cleaning
Industrial laundries
Laundry and garment services,
not elsewhere classified
Car wash establishments
SIC 72 11
SIC 7213
SIC 72 R
SIC 7215
SIC 7216
SIC 721 7
SIC 7218
SIC 7219
SIC 7542
3,100
1,300
300
32,000
28,400
2,700
1,000
2,700
22,000
3.1.1 Power Laundries, Family and Commercial (SIC 7211)
Power laundries are defined as establishments primarily engaged in operating
mechanical laundries with steam or other power. Laundries using small power
equipment of household type are included in the Laundry and Garment Services Not
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Elsewhere Classified subcategory. Also excluded here are establishments that have
power laundries but are primarily engaged in specialty work, such as diaper
services, linen supplies, or industrial laundries.
In 1967 this category accounted for 11% of all laundry establishments and 20%
of all laundry receipts (2). In recent years power laundry receipts have declined
greatly. In the period from 1963 to 197* they declined by 64%, even though the
population and the gross national product (GNP) rose significantly (3). A major
reason cited for this decline is the development of wash and wear fabrics, which
eliminated much of the tedious finishing work (ironing in particular) associated with
doing laundry. This has encouraged the use of coin-op laundries, which are less
expensive, and the use of home laundry equipment, which is economically
competitive with, and more convenient than, coin-ops. To offset these losses,
power laundries are increasingly providing other services including coin-operated
laundry and dry cleaning, rug cleaning, dry cleaning, linen rental,
industrial laundering, and diaper services. However, there are no indications that
this trend will reverse itself in the near future, and it is expected that the decline
will continue until a point is reached where power laundries are supported by a
relatively small but stable portion of the population.
Currently 75% of power laundry receipts are from traditional family and
bachelor-type work, but almost 18% is derived from dry cleaning (2).
3.1.2 Linen Supply (SIC 7213)
Linen supplies are defined as establishments engaged primarily in supplying, on
a rental basis, laundered items such as bed linens, towels, table covers, napkins,
aprons, and uniforms. These establishments may operate their own power laundry
facilities or they may contract the actual laundering of the items they own.
Sales in the linen supply business have been increasing at a moderate rate
over the 1963-to-197<* period), but recent sales figures indicate that this
growth is leveling off (3). However, there is a possibility that in the future an
upswing in growth will be observed if energy prices continue to increase. This is
because linen supply laundries are more efficient in water, chemical, and energy
usage than are on-premise laundries. If energy prices increase to the point where
energy is a major cost item, it may become more economical for a linen user to
contract for linen supply services than to continue using an existing in-house
facility.
Major competitors in the linen supply market are disposable items, on-premise
laundries, and industrial and power laundries that engage in linen supply activities.
Disposable napkins, paper towels, and the use of paper place mats rather than table
cloths in particular have cut into the restaurant market. To compensate for these
losses many linen suppliers have expanded their services to include work
traditionally done by industrial laundries. Industrial type work may account for as
much as *0% of the work done by the linen supply business (W).
3.1.3 Diaper Service (SIC 7210)
Diaper services are defined as establishments primarily engaged in supplying
diapers (including disposables) and other baby linens to homes, usually on a rental
basis. Diaper services may or may not operate their own power laundry facilities.
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There are approximately 300 such firms in the U.S., which account for about 0.6%
of total laundry receipts (I).
The diaper service industry has not diversified as have many of the other
laundry categories. Traditionally they have rented diapers and other baby linens to
household users. This role has remained essentially unchanged except -chat
disposable diapers are now also supplied to customers. Approximately 95% of the
receipts are derived from the traditional sources (2). The number of establishments
and 'receipts for this industry have been declining due to the failing birth rate and
the increasing popularity of disposable diapers.
3.1.* Coin-Operated Laundries and Dry Cleaning (SIC 7215)
The coin-op category is made up of establishments primarily engaged in
providing coin-operated laundry and/or dry-cleaning equipment on their own
premises. Included are establishments known as "laundromats," "self-service dry
cleaners," etc. Also included are establishments that install and operate coin-
operated laundry machines in apartment houses, motels, etc.
Coin-ops were introduced in the 1950's and by 1960 had numbered 20,000
establishments. By L972 this figure had increased by 100% to 40,000 (3). Over the
past decade coin-op receipts have increased by 10% per year, and it is expected
that future growth will continue at a moderate rate.
Most coin-ops offer their customers other services besides self-service
washers, dryers and dry-cleaning equipment. These usually include the sale of
soaps, bags, hangers, candy, soft drinks, and cigarettes via vending machines.
However, these other services account for only 9% of coin-op receipts. In 1967 this
subcategory encompassed 28% of all laundry establishments and accounted for
almost 9% of total laundry revenues (2).
3.1.5 Dry-Cleaning Plants Except Rug Cleaning (SIC 7216)
Establishments belonging to SIC 7216 are defined as those primarily engaged in
dry cleaning or dyeing apparel and household fabrics, other than rugs, for the
general public. There are about 28,000 establishments in this category, most of
which are relatively small. Dry-cleaning plants accounted for 54% of all laundry
establishments and about 41% of all laundry receipts in 1967 (2).
The number of dry-cleaning establishments and real receipts in this segment of
the industry have both declined by 29% from 1963 to 1974 (3). This is largely due to
the new clothing fabrics developed over the past 20 years. Many of these fabrics do
not require dry cleaning or shed soil more easily and hence require it less often.
Dry cleaners have diversified into related fields such as shirt cleaning and
laundering in order' to provide customers with one-stop cleaning services.
Relatively recent developments are drapery, rug, and furniture cleaning and the
sale and/or rental oi working apparel.
3.1.6 Carpet and Upholstery Cleaners (SIC 7217)
Carpet and upholstery cleaners are defined as establishments primarily
engaged in cleaning carpets and upholstered furniture at a plant or on a customer's
-------
premises. It is estimated that 25% of :nese Dusir.e'-ses operate in-plant cleaning
facilities. The number of in-plant operations has declined significantly over the last
10 years with a corresponding growth in the on-location type cleaners. This is a
result of the increase in the use of wall-to-wall carpeting.
Firms in this category are not very diversified. Their basic services include
carpet and rug cleaning, repairing, and dyeing, and upholstered furniture cleaning.
Approximately 85% of the receipts are from these activities (2). A small number of
these firms offer in-piant dry-cleaning services for specialty items such as
Orientals, Aubussons, Savonneries, and tapestries.
3.1.7 Industrial Laundries (SIC 7218)
Industrial laundries are establishments primarily engaged in supplying
laundered or dry-cleaned work uniforms, wiping towels, safety equipment (gloves,
flame resistant clothing, etc.), dust covers and cloths, and similar items to
industrial or commercial users. These items may belong to the industrial
launderers and be supplied to users on a rental basis or they may be the customer's
own goods. Establishments included in this SIC category may or may not operate
their own laundry and dry-cleaning services.
Most industrial launderers offer their customers a variety of textile
maintenance services, but approximately 88% of the receipts are derived from the
activities defined above (2). Although there is some overlap in the work done by
industrial launderers and linen suppliers, industrial launderers in many cases can be
distinguished as they rent personalized garments fitted and labeled for the
individual, while linen suppliers provide rental garments by size. This distinction,
however, has been rapidly disappearing in recent years (45).
In 1967 this category accounted for l.*96 of all laundry plants and 12% of the
total receipts of the laundry industry (2). The average annual growth rate of
receipts dropped from approximately 11% during the 1963-to-1967 period to 6.6%
during the period from 1972 to 197* (3). Became of the nature of work processed,
receipts in this category are closely tied to the GNP.
3.1.8 Laundry and Garment Services Not Elsewhere Classified (SIC 7219)
This segment, Laundry and Garment Set vices NEC, is defined as those
establishments primarily engaged in furnishing other laundry services, including
repairing, altering, and storing clothes for individuals and the operation of Chinese,
French, and other hand laundries. Additional services provided by these firms
include fur garment cleaning, repairing, and storage; glove mending; hosiery repair,
pillow cleaning and renovating; and tailoring. There are approximately 2,700
establishments in this category, most of which are very small (1).
3.1.9 Car Washes (SIC 7542)
The auto laundry is comprised of facilities designed for the automatic or self-
service washing of vehicles including cars, vans, and pick-up trucks. There are three
types of car washes, tunnel, rollover, and wand, which will be described in 3.2.5.
10
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The industry, as a whole, continues to grow at a rate of 3-*% a year, although
the growth' rates for each of the three types of facilities will vary. The number of
new tunnel facilities has been fairly constant since their inception. The cost of land
in many cities has become a major part of the capital outlay for a new facility, and
thus the cost of these facilities may be prohibitive. Rollovers are primarily found at
service stations where oil companies have often used them as promotional devices,
sales, are therefore dependent on such things as the availability of gas. A company
will.not want to promote a product that is difficult to obtain, and so when a gas
crunch occurs, sales fall off. However, if different marketing techniques are used,
and .the carwash is not viewed as a promotional device but rather as an additional
source of income, sales should not be greatly affected.
The largest sales increase has been for the self-service wand type facilities.
The resurgence in sales is partly due to a general upgrading of both merchandise and
facilities. Furthermore, wand washes offer the highest return on the least
investment of the three types of facilities. The number of bays installed at a
location is generally based on market studies. These studies normally show that an
initial four bay set-up is the most economical.
Car wash manufacturers are generally optimistic concerning future sales of
auto washing equipment. As cars become more and more expensive, owners will
keep them for ionger periods of time, and must therefore take better care of them.
This better care will include maintaining the appearance of the auto. Also, in many
areas (e.g., apartment complex carports and driveways) people are no longer
permitted to wash their cars, and must take them to a carwash for cleaning.
3.2 INDUSTRY PROCESSES
The unit operations for this industry can be separated into those used at
laundries and those used for auto washing. There are four basic types of processes
employed within the laundry industry: water wash (laundering), dry cleaning, dual
phase processing, and carpet and upholstery cleaning. Auto washes consist of
tunnel, rollover, and wand type facilities. Brief descriptions of these processes are
provided below.
3.2.1 Laundering
The particular processes and types of equipment used in a laundry depend to a
considerable extent on the types of services offered.
Process—Upon entering a laundry, soiled materials are first sorted so that
items requiring similar processing can be grouped and weighed into washer loads.
Sorting may be done on the basis of fabric type, color, soil type, ownership, or type
of garment (for example, shirts are often separated from other types of laundry as
are hosiery and bed linens). During the sorting process, items requiring prespotting
and destaining are identified. Prior to laundering, stains such as blood or food soil
which may set as a result of the washing process must be removed. Other types of
stains may be removed either before or after washing. Destaining procedures vary
from simple soaking in cold water to the use of acids, bleaches, and/or multiple
organic solvents.
11
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Once a laundry load is put in a washing machine, it undergoes a series of
cycles in which various processing operations are carried out. The number and types
of operations performed at a given laundry are dependent on the types of items,
composition of the fabrics, and the soil classification. The first cycle is generally a
flush in which water is used to wet the fabrics and to remove loosely attached solids
and a portion of the water soluble soils. This may be followed by an optional cycle
known as the break. Here the garments are treated with an alkali solution to swell
cellulosic fibers so that soil is more easily removed. For the actual wash cycles
(sudsing), the multiple sudsing procedure in which faeries are agitated in repeated
changes of detergent solution until they are clean is widely accepted as the best
means of removing soil and preventing its redeppsition on the fabrics. In this
process, soiled garments are agitated in a soap solution until the rate of soil removal
per minute of running time has nearly leveled off to zero (5 minutes to 7 minutes).
This solution is then dumped except for approximately 2.5 x 10'3 m3 of solution per
kilogram of fabric (0.3 gal/lb), which is retained by the load. The retained water
holds soil in suspension that cannot be removed by rinsing with clear water. This is
because the rinse water would dilute the soap solution to such an extent that soil
would be redeposited rather than remain in solution. Therefore, a clean soap
solution is again added to the wash load and the above procedure is repeated until
the soil content of the wash solution is reduced to a minimum (4).
The sudsing cycles are usually followed by a bleach cycle where the detergent
solution is replaced by a bleach solution. A series of rinsing cycles are then
performed to reduce the alkali and soap content of the fabrics to a minimum. At
this point, depending on the nature of the load, a blueing or brightening cycle may
be included. Alternatively, brighteners are often included in other wash supplies
such as soaps, antichlors, or sours. The final operation is usually a souring
treatment. This involves reducing the pH of the final bath to about 5 to prevent
yellowing of fabrics caused by the presence of sodium bicarbonate during pressing.
After laundering, clothes retain a quantity of water equal to about 2.5 times
their dry weight. Most of this water is removed in a centrtfugelike device called an
extractor. A perforated basket located in a metallic shell is rotated at liigh speeds
so that a large percentage of the moisture is thrown off in a 5-minute to 15-minute
period. When removed from an extractor, fabrics generally retain moisture
equivalent to only 50% of their dry weight and are ready for pressing or other
finishing operations.
Equipment—Washers used in professional laundries can handle loads from 9 kg
(20 Ib) to «0 kg (1,000 lb). This equipment usually consists of a perforated
horizontal cylinder which rotates inside of a shell. Cylinders are equipped with ribs
that project toward the center and run the length of the cylinder. These serve to
lift fabrics as the cylinder rotates and then allow them to drop back into the
washing solution. The diameters of cylinders range from 0.6 m (2* in.) to 1.5 m (60
in.), and lengths vary from O.W m (18 in.) to 3.2 m (126 in.). Most washers are
equipped with thermometers for temperature control, gages for control of water
levels, timing devices, and reversing devices so that the direction of rotation can be
changed after every four or five revolutions (4).
Automatic washers are being used to a considerable extent. This equipment
allows the operator to load a washer, load supply compartments, start the machine,
and not return until the entire wash cycle has been completed. In some of this
12
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equipment, the top part of the shell opens to allow the cylinder to rise out and
automatically deposit the wash load into trucks or an adjacent extractor. However,
the current trend is toward combination washer-extractors so that laundry can be
washed and extracted in the same machine. While this saves the transfer operation
and the floor space occupied by an extractor, it also reduces the volume of laundry
that can be handled by a single machine because of the extra time required for the
extraction cycle.
Recently two other washer designs have become available: the tunnel washer
and modular washer. Tunnel washers provide continuous operation and can process
up to 750 kg of laundry per hour (1,870 Ib/hr). Tunnel washers employ the
counterflow process whereby water at tap temperature enters the system at the
discharge end for the final rinse and then flows through the rinse and suds bath
before being discharged to a drain. Live steam may be introduced at several points
along the tunnel to heat the water to the desired temperature for rinsing, bleaching,
and sudsing, or high temperature zones can be located within the tunnel to heat the
water.
This process is fully automatic. Water, steam, and laundry chemicals can be
mechanically injected into the system, and following washing, the work can be
moved by a conveyor to an extractor and then to a dryer. One point common to all
tunnel washers is the reduction in water use. In conventional washers 1.3 x 10~2 m3
to 4.2 x 1Q-3 m^ of water are used per kilogram of laundry processed (1.5 gal/lb to 5
gai/lb), while tunnels generally use 5.8 x 1Q~3 m^ to 1.3 x 10~2 m^ per kilogram of
laundry (0.7 gal/lb to 1.5 gal/lb) (6). Less water usage also results in using less
energy and chemical supplies. While these machines are becoming very popular in
Europe, their use in the U.S. is extremely limited.
Another innovation in wash equipment is the modular unit. It can be used
alone or in combination with other units to provide flexibility in machine capacity.
These washers are of a shell-less design, with agitation provided by 25% of the wash
solution surging in and out of the machine. Units of this design are loaded irocn the
top by hopper, sling, or conveyor and are unloaded through a front door. When
accompanied by conveyors, a hydraulic extractor, and a tumbler, a fully automatic
system may be achieved.
3.2.2 Dry Cleaning
Dry cleaning refers to the cleaning of fabrics in an organic-based solvent
rather than in an aqueous-based detergent solution. When certain hydrophilic fibers
are washed in water they swell and undergo a dimensional change that results in
wrinkles and shrinkage. This can be avoided by the use of dry-cleaning solvents or
solvent/detergent mixtures. There are two other advantages to dry cleaning.. The
solvents used in dry cleaning dissolve soils at low temperatures and under generally
mild conditions as opposed to the laundering process, which involves a complex
colloidal mechanism at high temperatures and the use of relatively harsh chemicals
such as alkalies and bleaches. Thus, dry cleaning results in considerably less wear on
a fabric. Dry cleaning also uses much less water than laundering. This results in
savings on both the cost of water and the cost of discharging to a sewer.
There are five types of laundries that use dry cleaning at least to some extent:
commercial dry cleaners (SIC 7216), industrial laundries (SIC 7218), power laundries
13
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(SIC 7211), linen supplies {SIC 7213), and coin-ops (SIC 7215). The general
processing steps undergone in a dry-cleaning plant are similar to those lor
laundering. They are (7);
(1) Items are marked and sorted.
(2) Prespotting is performed where needed.
(3) Garments are weighed into machine loads to prevent overloading.
.(<*) Loads are rotated in tumble-type washers in one or more solvent baths.
(5) Excess solvent is removed by extraction.
(6) Solvent remaining after extraction is removed in heated dryers (often
incorporated into a washer/extractor).
(7) Clean garments are inspected and spot cleaned if necessary.
(S) Finishing operations (pressing, steaming, etc.) are performed to restore
garments as near as passible to their original size, shale, feel, and
appearance.
(9) Individual orders are assembled and wrapped or bagged for customer
pick-up or delivery.
In addition to the above procedures, commercial dry cleaners may also offer
such services as water repellent treatment for rainwear, moth repellent treatment
for wools, leather cleaning, and resizing of garments.
The procedure used for industrial dry cleaning is similar to that listed above
except that there is less variety in the types of items handled and thus there is less
sorting involved. The procedure for coin-op dry cleaning is analogous to operating a
coin-op washing machine except that neither chemical addition by the customer nor
drying of the garments is required. Clothes are loaded into the machine prior to
cleaning and are removed already dried after cleaning.
Processes—There are three methods used in dry cleaning: charged system,
fresh soap added to each load, and no soap added (8). In the charged system, a
detergent and a small quantity of water (usually 0.5% to *%) are added to the dry-
cleaning solvent. The detergent forms discrete hydrophilic aggregates of molecules
(micelles) which are dispersed throughout the solvent. Water addd to this solution is
absorbed by the micelles, which then become capable of dissolving water-soluble
soils without danger of serious wrinkling or shrinkage of fabrics. In this type of
system the water-detergent concentration in the solvent must be maintained
throughout the washing process. This is accomplished by the use of conductivity
meters to automatically control the addition of water and detergent.
In the second method, the solvent is charged with a given amount of soap or
detergent at the beginning of each load and does not receive any additional charge
during the cleaning cycle. Since soap is not metered, the maximum quantity of
14
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water cannot be added without risk of damaging the fabrics and the solvent filtering
system. Therefore, maximum efficiency is not achieved with this system.
As the name implies, the no-soap method uses only dry-cleaning solvent.
Because of this, prespotting is necessary to remove water-soluble soils.
Equipment—Standard dry-cleaning equipment consists of a rotating cylinder in
a stationary shell as described in the previous section on laundering. However, dry-
cleaning equipment also includes one or more solvent stroage tanks, a filter system
for cleaning the solvent as it is used, a solvent/water separator, distillation
equipment for solvent purification, and, often, a device for recovering solvent
vapors (a condenser or an activated carbon filter).
Depending on the cleaning method used, dry-cleaning equipment may include
one or two solvent storage tanks and filtering systems. The latter is required with a
two-soivent-bath system, in which a pure solvent or solvent/detergent mixture is
used to clean the garments and then extracted, and the garments are rinsed in clean
solvent that is also extracted, as opposed to garment-treatment in a single solvent
or solvent/detergent mixture. In the two-bath system, contamination of the rinse
solvent is controlled by using it for make-up in the wash solvent tank.
A number of solvent filtering devices have been described in the literature (9-
11). These generally consist of diatomaceous earth, sometimes mixed with silicates
or activated carbon, coated onto a wire mesh screen, or of filter cartridges which
often incorporate a pleated paper filter around an activated carbon core. Solvents
trapped in the filter muck are often recovered by steam distillation of the used
filter materials in a "muck cooker." Recovery is completed by condensing the
distillation vapors and sending the condensate to the water/solvent separator.
Filters are efficient at removing suspended impurities and some soluble organics,
but in order to limit the buildup of odor-causing contaminants the solvent must be
distilled. Because distillation is relatively expensive, it is practiced only to prevent
solvent from becoming fouled rather than to produce a completely purified solvent
for each load. This is accomplished either by continuously distilling a small
slipstream of the circulating solvent as it comes from the filter or by periodically
distilling a portion when required due to odors or off colors. Because water and
perchloroethylene form an azeotropic mixture, they are codistilled and the
condensate must pass through the water/solvent separator (12).
When the more expensive chlorinated or fluorinated solvents are used it is
usually economically advantageous to recover the solvent that vaporizes during
drying of garments. Such solvents are recovered by condensation or trapped in
activated carbon and recovered by steam injection and subsequent condensation. In
either case the recovered solvent is fed to the water/solvent separator to remove
the water. In the separator, water and solvents are separated by the differences in
their specific weights. Water is decanted from the solvent after separation and
discharged. The solvent/water separator and the noncontact cooling water used for
condensation are the only two sources of wastewater from the dry-cleaning process.
3.2.3 Dual Phase Processing
Dual phase or dual stage processing is a cleaning method that employs a
water/detergent wash and a separate solvent wash. This method is used almost
exclusively by industrial laundries to clean items that contain large amounts of both
15
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water-soluble soils and oil and grease. Major items cleaned by this process are work
shirts (pants and overalls are usually cleaned by the charged system dry-cleaning
process) and wiping rags. The advantage of dual phase processing for shirts is that it
extends the life of garments made of polyester/cotton blends. If these garments
were only water washed, strong detergents and high temperatures that would result
in increased wear would have to be used. In the processing of wiping rags, an initial
solvent-cleaning step greatly reduces the pollutant loading of the subsequent
wash waters.
The order of processing is determined both by the reason dual phase processing
was selected and by the choice of solvent. When perc is used as the solvent in the
cleaning of work shirts, the water wash is done first to minimize solvent losses.
When petroleum-based solvents are used, the solvent cleaning step is usually done
first. Other factors which may affect the order include the type of soil and drying
energy requirements.
3.2.<> Carpet and Upholstery Cleaning
Rug and carpet cleaning may be done either on location or in a cleaning plant.
Over the last 20 years there has been a gradual shift from in-plant processing of
rugs and carpets to on-location cleaning. As a result, the majority of the rug and
carpet cleaning firms do only on-location work and subcontract in-plant cleaning to
a few centralized establishments still engaged in this business. Cleaning methods
used by both types of firms are described below.
On-location carpet cleaning is done by either the powder, dry foam, rotary
brush, or hot water extraction method (8). When using any of these methods the
carpet is usually vacuumed to remove loose soil and prespotted to remove stains
prior to cleaning. In the first method, a powder is worked into the carpet, left to
absorb soil, and then vacuumed up. Usually an absorbent clay or cellulosic-based
powder, such as sawdust, saturated with a volatile solvent is used to help dissolve
oily dirt and loosen paniculate matter. This process generates no wastewater. A
low water, high foam detergent solution is used for cleaning in the dry foam process.
The foam is worked into the carpet either by hand or machine and then extracted by
wet or dry vacuum. Cleaning by the rotary brush method consists of working a
detergent and water mixture into the carpet with a rotary brush machine followed
by vacuum extraction. In the hot water extraction process, a hot detergent solution
is injected into the carpet pile under pressure and then immediately wet vacuumed
out. All of the processes that involve a wet vacuum step generate a small quantity
of wastewater. This is usually disposed of on site when the capacity of the machine
is reached.
Depending on the size of the rug, in-plant cleaning may be done in a rug
cleaning machine or on a special cleaning floor for large area rugs too big to pass
through an automatic cleaning machine. In either case the preliminary cleaning
steps are similar. First, loose soil is removed by mechanically beating the carpet
with metal or leather straps or by use of a high speed vibrator while the rug is
positioned over a suction box with the pile down. This step may be omitted at some
plants or for some rugs. Stains are removed by prespotting with various solvents.
This is followed by a prewash in which a detergent solution is worked into the pile.
A high pressure sprayer, a rotary brush, or a combination of the two may be used for
this purpose.
16
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At this point the rug is either scrubbed by a rotary brush on a wash floor . id
then spray rinsed or it is fed over a cylinder or a flat bed through a detergent spray
at high or low pressure. If low pressure is used, the carpet passes through
reciprocating brushes to work the detergent into the pile. If high pressure is used,
teethed rollers or vibrator rolls are used to force the detergent solution into the
pile. This is followed by a squeegee roll that squeezes the detergent solution and
suspended soil out of the carpet. Thereafter, methods vary somewhat but most
systems then rinse the rug and send it through a second set of wringers.
After washing, rinsing, and wringing, rugs are removed to a drying room. Here
hot air at a temperature around 60°C is pulled across the rugs by large fans until
they are dry.
A few plants maintain rug dry-cleaning machines that are used only for very
delicate and dye-sensitive rugs and tapestries. The only wastewater discharged
from this process is the noncontact cooling water used to condense vapors from the
distillation unit and the small amount of moisture in the rug due to the relative
humidity at the time of processing. The latter is separated from the solvent in a
gravity separator and then discharged.
Upholstery cleaning is usually done on site and involves very little or no water,
so that no real effluent stream results. Processes used are absorption by a cellulosic
or clay-based powder, wet shampooing with a detergent solution, dry-cleaning, or
foam shampooing.
3.2.5 Auto Laundry
There are three main types of car washes: tunnels, rollovers and wands. All
three types use basically the same processes to wash the auto, however the type of
equipment used to accomplish this task varies.
Process—The first step in washing an auto is the application of detergents and
water and mechanically removing the dirt. This may be accomplished by brushes or
high-pressure streams of water. The auto is then rinsed with clean water to remove
the dirt and soap. Finally, the auto is dried either by a blower as in a tunnel or by
the owner in a wand-type facility.
Equipment—The tunnel wash is the largest of the three types and is usually
housed in a long building. The vehicle is pulled by a conveyor or driven through the
length of the building, passing through separate washing, waxing, rinsing, and drying
areas. A trench, usually running the length of the building, collects the waste
waters. Because of this design, it is possible to keep the wash and rinse waste
waters separate by installing a dam in the trench. This facilitates the treatment
and partial reuse of the waste waters.
At a rollover wash, the vehicle remains stationary while the equipment passes
over the car. Similar in design are the exterior pressure washes which utilize high-
pressure streams of water in lieu of brushes. At both types, all the wastewater is
collected in a single trench, usually situated beneath the car.
The car also remains stationary at a wand wash, but here the customer washes
his own car with a high pressure stream of water from a hand-held wand. As at a
rollover, both the wash and rinse waters are collected in a single trench or sump.
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SECTION 4
INDUSTRY SUBCATEGORIZATION
The auto and other laundries industry is composed of a large number ol
individual firms which provide services to a variety of customers. The mix of
customers that a laundry or auto wash serves, the volume of business that it does,
the particular chemicals, processes, and equipment used, and many other factors
have an effect on the volume and composition of the wastewater it generates. In
order to set effluent standards which are realistic, these differences must be
accounted for. This is accomplished by dividing the industry into individual
segments, or subcategories.
*.l FACTORS CONSIDERED FOR SUBCATEGORIZATION
4.1.1 General Types of Cleaning Processes Employed
The three general types of cleaning processes used in the laundry industry are
water wash, dual-phase, and dry cleaning. The degree to which each of these
processes are used in a given laundry establishment is a primary determinant of
wastewater volume and composition.
Table 4-1 summarizes data obtained by industry survey on the application of
these general types of cleaning processes in industrial laundries, linen supplies, and
power laundries.
Although dry cleaning is performed by most industrial laundries and a
significant percentage of linen supplies and power laundries, a large majority of the
' garments and flatwork articles handled by these establishments are water washed.
Dual-phase cleaning is only practiced to a significant extent in the industrial laundry
subcategory.
None of the 25 diaper services responding to the industry survey reported the
use of dual-phase or dry cleaning methods. Only 5 of 35 coin-operated laundries
surveyed during this study have self-service dry cleaning machines on their
premises. Where this type of service is offered by coin-operated laundries, it
usually accounts for only a small percentage of the total business. As explained in
Section 3, in-plant carpet cleaners do not use solvent washing techniques to a
significant extent either.
The dry cleaning plant segment (SIC 7216) of the laundry industry is the only
subcategory where the majority of the workload is dry cleaned rather than water
washed. Wastewaters discharged by these establishments are considerably different
in terms of volume and composition than the wastewaters discharged by other types
of laundries. These differences are illustrated in Section 5 of this report.
A small number of industrial laundries surveyed during this study dry clean the
majority of their workload. One industrial iaunderer reported that only 20% of the
total poundage processed at his plant is water washed. Even under these conditions,
however, the vast majority of the process wastewater originates from aqueous
rather than dry cleaning processes.
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TABLE *-l. GENERAL TYPES OF CLEANING PROCESS USED BY INDUSTRIAL LAUNDRIES,
LINEN SUPPLIES, AND POWER LAUNDRIES
Percent ol total poundage
Subcategory/Process
Industrial laundries
Water wash
Dual-phase
Petroleum solvent/water
Water /per chlorelhylene
Dry Cleaning
Linen supplies
Water wash
Dual -phase
Petroleum solvent/water
Water /perdiloroe thy lene
Dry Cleaning
Power laundries
Water wash
Dual-phase
Petroleum solvent/water
Water /uerchloroethylene
Number of
Number ol respondents
respondents using process
74
74
10
7
32
58
38
3
1
13
21
21
0
2
Minimum
19.3
0
0
0
80
0
0
0
59
0
0
Maximum
100
49
73
80.3
100
20
6
17
too
0
10
Mean lor
all respondents
Sl.l
3.1
2.2
12.9
97.3
0.)
O.I
7.1
94.7
0
0.3
Mean for
respondent
using proce
81.1
23.2
23.3
IS. 4
97.3
9.3
6
8.1
94.7
0
3.3
Dry cleaning
41
4.8
II.I
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t.1.2 Types of Garments and Flatwork Artl-i-as Cleaned
The nature and quantities of soil present on garments and flatwork articles
cleaned by laundries are primary determinants oi wastewater strength. Soil loading
is, in turn, determined from the environment in which these articles are used.
Table 4-2 identifies the general types and relative amounts of items cleaned
by industrial laundries, linen supplies, and power laundries, based on the results of an
industry survey.
TABLE 4-2. GENERAL TYPES OF GARMENTS AND FLATWORK
ARTICLES HANDLED BY INDUSTRIAL LAUNDRIES,
LINEN SUPPLIES, AND POWER LAUNDRIES
Percent of total poundage
for industry subcategory
Typea
Industrial garments
Industrial flatwork
Dust control items
Linen garments
Linen f Jatwork
Commercial and institutional
garments and flatwork ^
Family laundry
Diapers
OtherC
Industrial
laundries
45.0
22.0
16.0
1.1
4.7
<0.1
<0.1
0
11.1
Linen
supplies
5.2
2.1
4.2
7.8
69.0
6.8
0.3
1.8
2.8
Power
laundries
1.4
0.4
0.7
2.0
16.0
55.0
17.0
0.7
6.8
a Includes only water-wash and dual phase poundage, except where noted.
b Articles owned by the customer, not supplied on a rental basis.
c Includes dry-cleaned apparel and miscellaneous articles.
More than 80% of the total weight of material cleaned by industrial laundries
consists of industrial garments (i.e,, uniforms, coveralls, work shirts, and pants),
industrial flatwork items, particularly shop towels, and dust control items such as
mats, maps and tool covers. The major customers of industrial laundries are
chemical and manufacturing plants, automotive repair shops and service stations,
machine shops, printing establishments, and janitorial services. Garments and
flatwork articles used by these and other industrial laundry customers tend to be
more heavily soiled than the textiles cleaned by establishments in other
subcategories that service primarily nonindustrial customers.
Nearly 80% ol the work performed in the linen supply subcategory consists of
typical "linen" items such as napkins, tablecloths, bed sheets, pillowcases, towels,
aprons, and nonindustrial uniforms. Major linen supply customers include
20
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restaurants and food services, hospitals, motels, hotels, schools, other commercial
businesses 'and institutions. Linen garments and flatwork are usually much less
heavily soiled than their "industrial" counterparts, although restaurant linens can
be heavily laden with grease. Industrial garments, flatwork, and dust control it«:T;S
account for approximately 11 to 12% of the linen supply business (in terms of total
poundage).
Power laundries process many of the same types of items that are handled by
linen supplies. The major differentiation is that most of the articles cleaned by
power laundries are owned by the customer rather than by the laundry itself.
However, power laundries also wash a significant percentage of family-type
garments, unlike industrial laundries an'd linen supplies. Based on the survey
results, less than 3% of the total weight of material cleaned by power laundries is
"industrial-type" work.
As explained in Section 3, diapers and carpet account for the vast majority of
material cleaned in the diaper service and carpet cleaning segments of the industry,
respectively. Coin-operated laundries and commercial dry cleaners primarily cater
to individual customers and families.
Due to the nature and quantities of soil present on the major types of textiles
cleaned, industrial laundry wastewaters tend to be more heavily polluted than
wastewaters from other types of laundries. Linen supply wastewaters rank second in
strength on the average, followed by wastewaters from power laundries and diaper
services, carpet cleaners and coin-operated laundries, and dry cleaning plants. This
trend is illustrated in Section 5.
4.1.3 Types of Laundering Chemicals Used
Table
-------
TABLE 4-3. CLASSIFICATION OF CHEMICALS USED BY POWER
LAUNDRIES, LINEN SUPPLIES, INDUSTRIAL
LAUNDRIES, AND DIAPER SERVICES
Percentage of laundries which
report using each class of chemical
Chemical
class
Alkali*
Caustic Soda
Silicates
Phosphates
Soap •
Buiit Soap
Detergent
Bleach
Antichlor
Sour
Blueing and/or Brightener
Germicide or Bacteriostat
Mildew Inhibitor
Flame Retardant
Solvents
Dust and Treating Compounds
Starch
Power
laundries
67
25
17
4
50
38
67
100
29
96
29
25
4
13
33
13
88
Linen
supplies
67
23
30
11
33
39
81
95
44
98
9
37
68
16
25
58
84
Industrial
laundries
50
•28
28
18
14
28
73
77
30
76
15
18
17
32
44
55
49
Diaper
services
70
11
11
48
48
30
30
93
37
85
11
85
4
0
4
7
0
aOther than caustic soda.
The most obvious trends indicated by the data in Table 4-3 are:
o Phosphates and soaps are most widely used by diaper services, while
linen supplies and industrial laundries use synthetic detergents much
more frequently.
o Germicides and bacteriostats are most widely used by diaper services,
due to bacterial and viral contamination of diapers by feces.
o Mildew inhibitors are most commonly used for "linen supply" items,
which may be stored for extended periods of time.
o Solvents are most widely used in the industrial laundry subcategory
where dual-stage and dry cleaning operations are more prevalent.
o Flame retardants are also more widely used for Industrial-type garments.
o Dust and other specialty treating compounds are most commonly used by
industrial laundries and linen supplies.
22
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o Starch is used by the majority of power laundries and linen supplies, and
by approximately 50% of the industrial laundries surveyed.
The degree to which laundering chemicals such as sours, blueing and
brightening agents, germicides and bacteriostats, solvents, dust and specialty
treating compounds, etc., contribute to pollutant loadings in wastewater depends
upon the particular compounds selected and the quantities of these compounds that
are used in various washing applications.
The general types of laundering chemicals used in laundering selected
garments and flatwork articles are identified in Table 4-4. This information is based
on data from a -survey of industrial laundries, linen supplies, power laundries, and
diaper services. The quantity of each chemical used depends upon the particular
product employed, and widely varying usage rates were reported by different
laundry owners. In many cases, more than one generic type of laundering chemical
is contained in commercial formulations.
Because the same general types of chemicals are used in many different
washing applications and many different commercial formulations can be used
interchangeably, it is not possible to subcategorize the laundry industry on the basis
of chemical usage. The dry cleaning plant subcategory could be subdivided into
plants that use perchloroethylene solvent versus plants that use petroleum-based
solvents, however further subcategorization of this industry sector is not considered
critical due to the relatively small volumes of process wastewater that are
discharged by dry cleaning plants.
*.1.4 Age and Design of Equipment
Most of the new laundry equipment being marketed is of similar design to
older units except that they tend to be more automated and slightly more efficient
in the use of chemicals, water, and energy. One innovation in design is the counter
flow type of wash equipment which is popular in Europe but currently receives only
limited use in the U.S. This type of equipment has the potential to moderately
increase the strength of wastewaters simply because it uses considerably less water.
However, differences in wastewater quality and quantity due to the age of
wash equipment are generally very minor. Soils are removed from the laundry and
thus incorporated in the wastewater regardless of the age or type of equipment
employed. Therefore, any reduction in the mass of pollutants discharged will be
from reductions in or elimination of, the use of specific laundry chemicals. Since
there are substitutes available for most laundry chemicals which contain toxic
pollutants, the age of equipment is not significant in terms of pollutant discharge.
4.1.5 Operating Schedules
Most commercial laundries operate 5 days per week and approximately 8 to 10
hours per day. Coin-operated laundries, on the other hand, are open anywhere from
8 to 24 hours per day and are usually dosed only on holidays. However, some of the
larger linen supplies, power laundries, industrial laundries, and diaper services
operate 6 to 7 days per week and up to 24 hours per day.
Although the operating schedule of a laundry is significant in terms of
wastewater treatment system design capacity, it has no significance in relation to
23
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TABLE »-*. GENERAL TYPES OF CHEMICALS USED IN LAUNDERING SELECTED GARMENTS AND FLATWORK ARTICLES
Article
Shop towels
Industrial imlfornu
Vinyl mats
White table linen
Bed sheets
Colored apparel
Dt opera
Alkali*"
X
X
X
X
X
X
X
Ouillb
Silicates8 Soapb soap
X X
X
X
X
X
XXX
Bleach/
Delcrgenll* Solvent antichlor Dye
XX X
X
X
X X
X X
X X
Mildew
Sour Softener Starch Inhibitor
X
X XX
X X
X
X X
Germicide/
bacterioitat Salt
X
X
•Either alkali or silicates are normally used.
"Either soap, built soap, or detergent is normally used.
-------
wastewater characteristics. Effluent flow and composition vary from hour to hour
throughout'an operating day, however the overall waste characteristics depend upon
the types of garments cleaned and the types of cleaning process used rather than the
operating schedule.
*.1.6 Geographical Location
Laundries are found in all parts of the United States, but subcategorization on
this basis is not appropriate. Geographic location may be important in evaluating
treatment alternatives, however in this industry facilities are normally indoors.
t.2 GENERAL CONCLUSIONS
Subcategories selected for possible development of effluent limits or guidance
values for the°Auto and Other Laundries industry parallel the groupings established
by the Standard Industrial Classification (SIC) system. The segments selected are:
Power Laundries, Family and Commercial
Linen Supply
Diaper Service
Coin-Op Laundries and Dry Cleaning
Dry Cleaning Plants Except Rug Cleaning
Carpet and Upholstery Cleaning
Industrial Laundries
Classified
Car Washes
Although Laundry and Garment Services Not Elsewhere Classified is a segment
of the industry, they perform no cleaning operations and have no wastew,iter
discharge. For the purposes of this study, they are considered as a segment for
review but not as an actual subcategory.
The primary bases for the subcategorization scheme outlined above are (1)
differentiation by type of item to be washed, whether garments, diapers or autos,
and (2) the nature and quantities of soil present on these different items discussed
above. Soil loading is a primary determinant of wastewater composition., as
discussed in Section 5 of this report. The type of cleaning process used (e.g. water
wash versus dry cleaning) is also an important consideration in differentiating dry
cleaning plants (SIC 7216) from establishments in other industry subcategories. The
car wash subcategory is clearly demarked by the fact that only autos are cleaned at
these facilities.
25
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SECTION 5
WASTEWATER CHARACTERISTICS OF THE
AUTO AND OTHER LAUNDRIES INDUSTRY
This section identifies the sources, quantities and characteristics of
waste water discharged by the auto and other laundries industry. Subsection 5.1
discusses the various sources and quantities of wastewater in laundries and auto
washes. With regard to laundries, those using water-wash are contrasted with those
using solvent-cleaning processes with particular emphasis on process wastewaters.
Discharge rates are characterized in terms of m3/day (gal/day) and either nv/kg
(gal/lb) of material washed or m^/car (gal/car). Factors affecting wastewater ilow
variability between plants in different subcategories and between plants within the
same subcategory ars also discussed.
Subsection 5.2 identifies and discusses the characteristics of process
wastewaters in each industry subcategory. Ranges, median and mean concentrations
for seven conventional pollutant parameters and 129 toxic pollutants on the Consent
Decree list are presented and various factors that affect the concentrations of these
substances in laundry and auto wash wastewaters are discussed. In addition, the
toxic pollutant loads in kg/day of pollutants were calculated from the average flow
data found in Table 5-1 and presented along with concentration data.
5.1 WASTEWATER SOURCES AND QUANTITIES
5.1.1 Source of Wastewaters
Based on the industry survey results tabulated in Section 4, 95% or more of all
garments and flatwork handled in the linen supply, power laundry, diaper service,
carpet cleaning and coin-operated laundry subcategories are water-washed. Many
linen supplies, power laundries and coin-ops offer dry cleaning services, but this is
usually a very small fraction of the total business at these establishments. Dry
cleaning and dual-phase washing are more widely practiced in the industrial laundry
subcategory, but, here again, approximately 80% of the total workload is water-
washed.
For typical establishments in these subcategories, 70-»5% of the total water
metered into the plant is discharged as process wastewater. According to
representatives of the Linen Supply Association of America (LSAA), boiler
requirements account for 7 to 10% of the incoming water. Water remaining in the
textiles after extraction and subsequently evaporated during the drying cycle
accounts for 8 to 10% and miscellaneous uses (e.g., sanitary, equipment cleaning)
consume up to 10% of the total plant influent. The process effluent to fresh water
consumption ratio at any given laundry depends upon the types of cleaning and
finishing processes used and the types of garments and flatwork articles being
handled.
The total water-wash effluent includes each of the series of wash, rinse and
conditioning waters used in the process. Because the various laundry chemicals and
water added to and discharged from most washing machines are added and drained in
26
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batchwise fashion, effluent flow is quite va-:£2le. This variability is stabilized to a
certain extent in large laundries where many machines are operated in staggered
cycles; however, considerable flow variability still exists. Counterflow washing
machines, on the other hand, discharge the wastewater in a continuous fashion;
however, this type of equipment is rarely used in the United States.
Unlike laundries that water-wash the majority of their workload, commercial
(or industrial) dry-cleaning plants do not consume or discharge large quantities of
process water. In such plants, the major sources of wastewater are the noncontact
cooling water used to condense solvent vapors and the water used for sanitary or
other auxiliary purposes. The only sources of process wastewater are the following:
(1) trace quantities of water present in the fabric being cleaned, (2) small volumes
of water added to the solvent to remove sebaceous soils from the fabric, (3) solvent-
contaminated steam condensate from the regeneration of carbon columns used for
air pollution control and (4) solvent-contaminated steam condensate resulting ;:rom
the recovery of solvent from spent filter materials. Wastewater from each of these
sources is separated from the solvent by decantation and discharged directly to the
sewer. In all cases, extremely minor quantities of wastewater are involved.
•Many dry cleaning plants, particularly those using petroleum solvents rather
than perchloroethylenea, do not use carbon columns for air pollution control or
"muck cookers" for solvent recovery. In such plants, solvent-contaminated steam
condensate is not a source of process wastewater.
As previously stated, many linen supplies, power laundries, coin-ops and most
industrial laundries employ both water-wash and dry-cleaning processes. Typically,
the dry-cleaning process wastewaters generated in these plants are negligible in
comparison to the water-wash effluent. They may be combined with the water-wash
effluent for in-plant treatment and subsequent discharge, or discharged separately.
In the latter case, the dry-cleaning wastewaters are not subjected to the same in-
plant treatment (e.g.f lint screens, heat reclamation, etc.) as the water-wash
effluent; rather, they are discharged directly to the sewer connection or outfall.
The wastewaters from dual-phase processing (which is used to a significant
extent only in the industrial laundry subcategory) combine the characteristics of
water-wash and dry-cleaning effluents. When the solvent-wash cycle is performed
first (i.e., when petroleum solvents are used), the subsequent water-wash effluent is
contaminated by the solvent left in the fabric after extraction; otherwise, it is
treated in the plant and discharged in the same manner as any water-wash effluent.
When the water-wash cycle is performed first (i.e., when perchloroethylene solvent
is used), the total wastewater discharged from the process includes the water-wash
effluent plus the water remaining in the fabric after extraction, which is
subsequently removed from the solvent wash and decanted.
Perchloroethylene, tetrachlorethylene, and "Perc"
are simply different names for the same chemical.
27
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Water usage at auto washing facilities consists primarily of water used to wash
the autos. To wash the auto, detergent is added to water and is used for both
cleaning and brush lubrication purposes. After this water is used to clean the auto,
it is discharged as wastewater unless provisions have been made for recycle. In the
final operation the rinse water is used to dean the car of dirt and soap. This water
is also discharged unless provisions are made to recycle a portion of the flow.
5.1.2 Volumes of Wastewater Discharged
As indicated in the preceding subsection, considerably larger volumes of
wastewater are discharged from water-wash processes than from dry-cleaning
processes on a unit production basis. Commercial laundries typically consume
process water at a rate of 0.025 to 0.050 m3/kg (3 to 6 gal/lb) of material washed,
approximately 90% of which is discharged as wastewater. In the dry-cleaning
industry, however, water is usually added to the solvent bath at a rate of only 30 to
200 cm?/kg (0.004 to 0.023 gal/lb) of material washed (13). The fraction of this
water that is decanted from the solvent and discharged depends upon the particular
solvent-recovery system employed and varies from plant to plant. Other factors
that influence the total process-water discharge rate are listed below:
o Whether or not carbon columns are used for air pollution control and are
steam regenerated on site
o Whether or not solvent is recovered from spent filters by steaming
o The frequency at which these operations are performed and the quantity
of steam used per cycle
o The relative humidity and other conditions that affect the moisture
content of the fabrics being cleaned
Thus, the quantities of solvent-contaminated wastewater discharged from dry-
cleaning plants vary considerably across the industry. However, these discharge
rates are generally negligible (e.g., by a factor of 100) in comparison to
corresponding discharge rates for laundries in other industry subcategories that
water wash a comparable weight of material.
Table 5-1 lists the typical range and average of process water discharge rates
for establishments in the industrial laundry, linen supply, power laundry, diaper
service, coin-operated laundry, and the three types of auto laundry subcategories.
These figures are based on the industry survey data for process water consumption
and the assumption of 10% evaporative loss discussed in the preceding subsectiona.
In terms of total wastewater volume, linen supplies appear to be the major
dischargers followed by industrial laundries, power laundries, diaper services and
coin-operated laundries. Coin-ops are, by far, the smallest waste dischargers on a
plant-by-plant basis. In terms of wastewater volume per unit production, industrial
laundries tend to be the largest discharges at 0.038 m3/kg (4.6 gal/lb) of material
washed on the average. Average discharge rates for linen supplies, power laundries,
diaper services and coin-ops all fall in the 0.029 to 0.032 irWkg (3.4-3.8 gal/lb)
range**.
Similar data were not available for the in-plant and out-of-plant cleaning
segments of the carpet and upholstery cleaners subcategory.
Water consumption and discharge rates reported for coin-operated laundries
may be somewhat low due to the methods used to estimate the total poundage
of material washed.
28
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TABLE 5-1. REPORTED PROCESS WASTEWATER DISCHARGE RATES, BY SUBCATEGORY
to
—=======
Subcategory
Industrial laundries
Linen supplies
Power laundries
Diaper services
Coin-operated laundries
Car Washes3
Wand
Rollover
Tunnel
Minimum
0.008
(0.9)
0.014
(1.7)
0.018
(2.2)
0.006
(0.7)
0.007
(0.8)
m'/kR teal/lb)
Maximum
0.080
(9.6)
0.086
(10.3)
0.043
(5.1)
0.045
(5.4)
0.093
(11.2)
Average
0.040
(4.8)
0.033
(4.0)
0.029
(3.5)
0.029
(3.4)
0.032
(3.8)
0.13
(35)
0.15
(40)
0.30
(80)
. .
Minimum
32
(8,600)
14
(3,600)
6.8
(1,800)
12
(3,100)
0.9
(240)
m'/day fcpd)
Maximum
1,100
(290,000)
1,400
(360,000)
1,100
(290,000)
680
(180,000)
77
(20,000)
Average
260
(68,000)
410
(110,000)
230
(61,000)
160
• (41,000)
14
(3,600)
19.9
(5,250)
11.4
(3,000)
75.7
(20,000)
Flow per product is given as n.3 or (gal) per auto. Flow volumes are given as average estimates by the Industry. No
actual minimum or maximum values were measured.
-------
Wastewater discharge rates are affected by essentially the same factors that
affect process water consumption rates. The major factor affecting the total
volume of wastewater discharged is the quantity of garments and flatwork being
washed. Discharge per unit production rates are influenced by the types of
materials handled, the soil loading on these materials, individual washing machine
design and capacity, overall laundering capacity (larger laundries tend to be
somewhat more efficient in terms of water usage than smaller laundries) and the
degree to which wastewater recycle or reuse is practiced. In addition to the
aforementioned factors which influence process water consumption, wastewater
discharge rates are affected by the efficiency of the extractors used. In Table 5-1,
a universal wastewater-discharge-to-water-consumption ratio of 0.9 was assumed
because it is typical of the industry as a whole (according to LSAA representatives).
However, this assumption does not necessarily hold on a plant-by-plant basis.
Wastewater discharge rates for auto washes to a large degree depend upon the
type of facility, whether tunnel, rollover, or wand, and the number of autos washed.
A brief discussion of wastewater volumes for each type follows.
Tunnels; A tunnel wash has the capacity to handle SO-120 cars per hour,
although the actual number of cars processed is usually much lower. The number of
cars washed per day at a tunnel facility ranges from about 100 to 600, with the
average at about 250. When fresh water is used for all cleaning procedures, an
average of about 70 gallons per car is used. A large percentage of tunnel facilities
recycle their wash water, cutting their usage to about *0 gallons per car. Carry-out
and evaporation account for a water loss of 2-8 gallons per car. Tunnel washes then
use between W and 70 gallons per car depending on whether the facility recycles its
wastes or not. For the average facility, this amounts to between 10,000 and 17,500
gallons per day.
Rollovers: These facilities do a much smaller volume of business than do
.tunnels, washing, on the average, 75 cars per day, with a range of 10-150.
A typical rollover uses between 30 and 45 gallons of water per car depending
on the length of the cycle and the number of passes the equipment makes. Exterior
pressure washers may use as much as 90 gallons per car. The typical rollover will
discharge between 2,200 and 3,WO gallons per day with carry-out and evaporation
losses about the same as tunnels.
Wands; The number of bays at a self-service wand-wash may range from one
to over ten, with an average of about 5. Each bay can handle between 5 and 12 cars
an hour, depending on the length of the cycle and the number of cycles used. A
typical wand will provide 4 gallons of water per minute for 5 minutes, or 20 gallons
of water per cycle. The customer is usually able to choose from among wash, rinse
and wax modes and therefore the amount of water used for washing as opposed to
rinsing may vary. However, most people tend to use about 2/3 of the cycle for
washing and 1/3 for rinsing. Water losses at a wand wash may be greater than those
at tunnels or rollovers as the customer is able to point the wand in any direction,
causing water to be deposited in areas where it may not be collected in the sump.
Also, the high pressure (200-1000 psi) causes atomization of the water stream
leading to increased evaporation.
30
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There exist regional variations in the amount of water used at car washes.
These variations are the greatest where winter conditions in northern climates
often necessitate the use of salt and sand on the roads. Car washes in these areas
must deal with increased dirt loads consisting of ice, salt and grit. High volume
initial rinses are often used before the wash cycle and larger volume final rinses
may be necessary to remove any dissolved salts left on the car so that spotting is
minimized.
5.2 WASTEWATER CHARACTERISTICS
The characteristics of laundry wastewaters are influenced by three primary
factors: the general type of cleansing process employed (i.e., water versus solvent
wash), the types and quantity of soil present on the textiles being laundered and the
composition of the various chemical additives used in the process. Water -wash
effluents contain all of the soil and lint removed from the textiles, as well as the
laundry chemicals employed in the process. On the other hand, wastewaters from
dry-cleaning processes tend to contain water-soluble materials; lint, grit and
insoluble organic and inorganic compounds are largely removed by the solvent filter
or confined to the still bottoms. However, dry-cleaning effluents also contain
appreciable quantities of solvent, which are not normally present in water-wash
effluents. In car washes, the type of cleansing process (i.e., tunnel, rollover or
wand) will usually determine the concentration of various pollutants in raw waste
effluents due to the differing amounts of water used and thoroughness of the
cleaning process.
The types and quantities of soil present on the textiles or vehicles have a
major effect on effluent characteristics regardless of the cleaning method
employed. In water-wash processes, soil loading is the primary determinant of
wastewater strength and composition. This fact is clearly illustrated in subsequent
subsections of this chapter, in which the characteristics of wastewater from various
industry subcategories are compared. Industrial laundry wastewaters, for example,
contain considerably higher loadings than the effluents from coin-operated other
establishments processing nonindustrial garments and flatwork. Seasonal and
geographic differences also affect the types and quantities of soil
present, particulary in the car wash subcategory.
Although of lesser importance than soil loading, the choice of laundry formula
can also influence the characteristics of water-wash effluents. Several oi the
conventional and nonconventional pollutants and a few of the substances on the
toxic pollutant list are either present or suspected to be present in various
laundering chemicals. Choice of solvent is a major determinant of dry-cleaning
wastewater characteristics, as well. "Perc" (Perchloroethylene), the most popular
dry-cleaning solvent, is a toxic pollutant and several aromatic hydrocarbons on the
toxic pollutant list may be present in petroleum-based solvents.
Concentration data are presented in Subsections 5.2.1 and 5.2.2 for seven
conventional and nonconventional pollutants and each of the 129 toxic pollutants
found in auto and other laundry wastewaters. Minimum, maximum, median and
mean pollutant concentrations are shown for each industry subcategory and factors
affecting the variability in wastewater characteristics between subcategories,
between plants within a given subcategory and over a period of time at a given plant
are discussed. Where possible, the source(s) of each pollutant in the wastewater are
identified.
31
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As described in Section 2, the pollen*, concentration data were obtained from
industry trade association studies; Chics 53, Los Angeles and Dade County, Florida,
monitoring 'reports; industry survey questionaires; NPDES monitoring reports;
published and unpublished literature sources (14-22); and by sampling and analysis
performed in conjunction with this study. In the sampling and analysis programs,
plants were selected as being representative of each subcategory; no data is
available to indicate that the plants were not representative. In addition, the
number of plants sampled for each subcategory was considered valid in terms of the
subcategory characteristics.
5.2.1 .Conventional and NonconventionaJ Pollutants
The conventional and nonconventional pollutant parameters used to
characterize laundry wastewaters in this study include the following:
Conventional Nonconventional
o pH o Chemical oxygen demand (COD)
o 5-day biochemical oxygen o Phosphorus
demand (8005)
o Total organic carbon (TOO
o Total suspended solids (TSS)
o Oil and grease
The term pH is commonly used to describe the hydrogen ion -hydroxyl ion
balance in water. Numerical pH values are the negative, base-ten logarithms of
hydrogen ion concentrations in water and may range from 0 to 14. A pH of 7
indicates neutrality, while a pH below or above 7 indicates acidic or alkaline
conditions, respectively. The pH is often used as a surrogate indicator of excess
acidity or alkalinity in wastewater, although it is not a direct or linear measure of
either.
In composite auto and other laundry wastewater, the pH usually ranges from
8.0 to 11.0. These relatively high pH values are attributed to the use of alkali in the
break and suds cycles of the washing process.
Biochemical oxygen demand (BOD) is defined as the quantity of oxygen
required for biological and chemical oxidation of water-borne substances under
ambient conditions. The test for BOD is a standardized, bioassay procedure that
measures the amount of oxygen consumed by selected microorganisms in the
degradation of carbonaceous organic materials, ammonia and other oxidizable
nitrogen compounds under conditions similar to those that occur in the aquatic
environment. Thus, the BOD test does not measure the concentration of any
specific compound in wastewater; however, it does provide a relative measure of the
oxygen demand exerted on receiving waters by all biodegradable substances in a
wastewater stream.
Since many substances biodegrade very slowly under ambient and test
conditions, it is not feasible to measure the total biochemical oxygen demand of a
waste stream on a routine basis. Thus, the standardized test is designed to measure
5-day biochemical oxygen demand (8005). Approximately 60 to 80% of the
carbonaceous oxygen demand is measured by this test, which provides a suitable
indication of waste strength in most cases.
32
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In auto and other laundry wastewaters, BOD^ concentrations are attributable
to organic soils on the textiles or vehicles being laundered and to soaps, detergents,
starches and other organic process additives.
Chemical oxygen demand (COD) is defined as the quantity of oxygen required
to completely oxidize waterborne substances that may or may not be biodegradable.
The test is a "wet chemical" technique conducted under acidic conditions, in which
strong chemical oxidizing agents (i.e., potassium dichromate) are added to the
wastewater sample in the presence of certain inorganic catalysts. The COD test
measures all pollutants that are measured by the BOD^ test, as well as many
pollutants that are slowly biodegradable or nonbiodegradable. Thus, it provides an
upper-bound estimate of the oxygen demand that may be exerted on receiving
waters by a waste stream.
Total organic carbon {TOO is a direct measure of the total organic material
present in wastewater, as opposed to a measure of oxygen demand. The TOC test is
an instrumental technique that measures all carbonaceous organics, regardless of
their potential biodegradability*.
BOD$ provides a more direct measure of adverse water-quality impact and it
is used much more widely for regulatory purposes than either COD or TOC. Thus,
BODj is preferentially used to assess treatment system efficiency in Section 7.
However, COD and TOC data are also presented in the following pages for purposes
of comparison.
Total suspended solids (T55) include all organic and inorganic materials that
are insoluble in wastewater and that are retained by standard pore-size filters in the
gravimetric test procedure used. Like the pH, BOD^, COD and TOC tests, the
suspended solids test is a gross measure of wastewater strength (e.g., potential
impact on surface water turbidity); it does not measure the concentration at which
specific chemical compounds are present in wastewater. Lint, inorganic soils,
organic soils (such as oils and greases) and process additives all contribute to
suspended solids loadings in laundry effluents.
"Oil and grease" is a term that includes a wide variety of fatty acids, soaps,"
ester, fats, waxes and various petroleum products that can be extracted from
wastewater by certain organic solvents. Freon extraction is the preferred EPA
method for oil and grease; however, the hexane and ether solubles test are also used.
Oil and grease may be of animal, vegetable, or mineral (petroleum) origin and
may be free or dispersed in wastewater. In the auto and other laundry industry,
most oil and grease present in the wastewater is highly dispersed. The major
sources are soil on the articles being laundered, soap, solvents that are sometimes
added to wash formulas for heavily soiled items and oil from the laundering
equipment.
Certain organics that are strongly resistant to oxidation are not measured.
Thus, reported TOC values are slightly less than the theoretical TOC.
33
-------
Unlike the aforementioned pollut—: parameters, phosphorus is a specific
chemical element widely found in nature (although not in its elemental form). It is a
necessary nutrient for biological growth, but it can lead to eutrophication of surface
waters when discharged in large quantities. In auto and other laundry waste waters,
the major sources of phosphorus are phosphate detergent builders.
5.2.1.1 Industrial Laundries
Table 5-2 summarizes the conventional and nonconventional pollutant data
obtained for 73 industrial laundries. For purposes of comparison, Table 5-3 shows
the concentration ranges at which these same pollutants (excluding pH) are normally
present in domestic sewage (23).
In comparison to domestic sewage, industrial laundry wastewaters typically
contain high loading of 800$, COD, TOC, suspended solids and oil and grease. The
median BOD$ concentration in 51 industrial laundry effluents was 920 mg/1.
However, BODj concentrations as low as 91 mg/1 and as high as 7,800 mg/1 were
observed, which attests to the extreme variability in industrial laundry wastewater
strength.
The median TSS concentration in 69 wastewater effluents was 700 mg/1.
Suspended solids loadings were also quite variable, ranging from 6S mg/1 to 6,100
mg/1. Oil and grease concentrations ranged from 17 mg/1 to 7,900 mg/1 in 66
industrial laundry effluents, with a median value of 730 mg/1.
The mean concentrations of BOD^, TSS and oil and grease were *0 to 50%
higher than the corresponding median concentrations of these pollutants. This
reflects the fact that the concentration distribution for each of these pollutants is
skewed to the high end of the range.
High concentrations of oil and grease, suspended solids and biodegradable
organics in industrial laundry wastewaters are primarily attributable to the nature
of the workload handled by industrial laundries. Heavily soiled uniforms, shop
towels and gloves used in the chemical and manufacturing industries often comprise
a substantial portion of the business handled by these establishments.
The variability in waste strength from one industrial laundry ta another is also
at least partially attributable to the soil loading on the articles being water washed.
The highest pollutant loadings are found in wastewaters from plant processing a high
percentage of wiping towels used in print shops, machine shops, automotive repair
shops, chemical plants and other heavy industrial operations. Much lower pollutant
concentrations are found in the wastewaters from plants handling a high percentage
of uniforms and dust control items used in light manufacturing concerns. •
Factors such as water usage per pound of material washed and the application
of dual-phase or dry-cleaning processes also affect the concentrations at which
various pollutants are found in industrial laundry wastewaters. For example, oil,
grease and many other organic substances are more soluble in organic solvents than
in water and, thus, they are not present to a large extent in the wastewaters from
solvent cleaning processes.
34
-------
TABLE 5-2. CONVENTIONAL AND NONCONVENT1ONAL POLLUTANT
CONCENTRATIONS IN INDUSTRIAL LAUNDRY
WA5TEWATEKS
mg/1
Minimum Maximum
Pollutant Number
Minimum
cone.
Maximum
cone.
Median
cone.
Mean
cone.
pH
BOD^
COD
TOC
TS5
Oil and grease
Phosphorus
62
51
60
2^
69
66
12
7.5
91
330
130
68
17
1.3
11.9
7,800
7,000
6,800
6,100
7,900
41.6
10.5
920
3,SOO
1,200
700
730
9.1
10.*
1,300
5,000
1,400
1,000
1,000
12.2
TABLE 5-3. CONVENTIONAL AND NON-CONVENTIONAL
POLLUTANT CONCENTRATION
IN DOMESTIC SEWAGE (23)
Typical concentration
Pollutant range, mg/1
BOD5 100-300
COD 250-1,000
TOC 100-300
TSS 100-350
Oil and grease 50-150
Phosphorus 6-20
35
-------
In 62.composite wastewaters for which data were available, the pH ranged
from 7.5 to 11.9 with a median value of 10.5. These high pH values reflect the use
of alkali in the break and suds cycles of the washing process. Phosphorus
concentrations, which ranged from 1.3 mg/1 to *1.6 mgyl in 12 industrial laundry
effluents, are attributable to the variable usage of phosphate detergent builders.
However, the median phosphorus concentration of 9.L mg/1 falls well within the
concentration range normally associated with domestic sewage.
In addition to plant-to-plant variability, wastewater strength at any given
industrial laundry may be quite variable from day to day and from hour to hour.
This is caused by the changing nature of the workload and, on an instantaneous basis,
by the particular wash-cycle effluents that are being discharged. For example, the
initial rinse, break and washwaters contain much higher pollutant loadings than the
final rinse waters.
Table 5-4 presents pH, BOD^, TSS and oil and grease data for the wastewater
from one industrial laundry sampled on 30 separate days over a several year period.
These data clearly illustrate the fluctuating characteristics of industrial laundry
wastes.
5.2.1.2 Linen Supplies
Table 5-5 summarizes the conventional and nonconventional pollutant data
obtained for 60 linen supply laundries. Comparing these results with the data shown
in Tables 5-2 and 5-3, it appears that linen supply wastewaters typically contain
higher concentrations of BODs, COD, TOC, suspended solids and oil and grease than
does domestic sewage, but much lower concentrations of these pollutants than do
industrial laundry wastewaters.
In 50 linen laundry wastewaters, BOD$ concentrations ranged from 58 mg/1 to
1,500 mg/1. Suspended solids concentrations were also quite variable, ranging from
20 mg/1 to 1,200 mg/1 in 59 plant effluents. In 52 plant effluents, oil and grease
levels varied from 27 mg/1 to 910 mg/1. The median concentrations of BODs,
suspended solids and oil and grease in these wastewaters were 610 mg/1, 360 mg/1,
and 300 mg/1, respectively. Similar mean concentrations were observed.
These concentrations are 1.5 to 2.5 times lower than the median BOD5,
suspended solids and oil and grease concentrations shown in Table 5-3 for the
industrial laundry subcategory and 2 to 3.5 times lower than the corresponding mean
pollutant concentrations in industrial laundry wastewaters. This is attributed to the
lighter soil loading on items such as bed sheets, pillowcases, towels, napkins,
tablecloths and uniforms, which comprise the majority of the linen supply business.
Phosphorus and pH were found at similar levels in industrial laundry and linen supply
effluents, which reflects the fact that these pollutants are introduced to the
wastewater by process additives rather than by soil on the articles being laundered*,
As indicated in Section «, many linen supplies service industrial-type garments
and flatwork articles as well as the more traditional linen supply items. Plant-to-
plant differences in the amount of "industrial laundry" work performed is a major
a Actually, high pH is induced by process additives O.e.f alkali).
36
-------
TABLE 5-4. VARIABILITY Or CONVENTIONAL POLLUTANT
LOADINGS IN WASTEWATER FROM ONE
INDUSTRIAL LALNDRY
Day
pH
BOD
T5S
Oil and grease
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Minimum
Maximum
Mean
Standard deviation
11.9
12.0
12.6
11.6
12.2
11.8
11.8
10.0
11.5
11.6
11.7
11.4
11.6
10.7
10.8
10.9
10.7
10.1
10.4
10.2
11.0
12.0
11.9
9.4
10.2
...
...
_._
-—_
.._
9.4
12.6
11.2
0.8
1,700
...
2,500
...
—
...
—
...
...
...
—
—
...
710
650
1,300
...
690
_-.
940
680
—
.--
___
—
930
1,400
1,600
2,200
3,700
650
3,700
1,515
989
2,300
2,100
2,400
1,900
1,900
2,100
5,000
2,800
3,600
4,000
3,800
2,700
2,300
810
650
3,500
1,700
1,800
...
2,600
4,400
3,800
5,300
—
—
1,300
2,400
2,000
2,000
2,600
650
5,300
2,658
1,169
490
1,800
2,200
240
5,300
2,100
2,800
2,600
3,400
3,400
3,800
—
—
400
510
1,600
970
720
1,200
1,200
2,600
3,500
3,900
1,500
1,400
2,400
2,300
2,400
1,300
2,400
240
5,300
2,087
1,234
37
-------
TABLE 5-5. CONVENTIONAL AND NONCONVENTIONAL POLLUTANT
CONCENTRATIONS IN LINEN LAUNDRY WA5TEWATERS
mg/1
Pollutant
pH
BOD,
CODJ
TOC
TSS
Oil and grease
Phosphorus
Number
58
50
26
28
59
52
5
Minimum
cone.
7.5
58
300
2S
20
27
5.4
Maximum
cone.
12.3
1,500
4,000
1,200
1,200
910
48.5
Median
cone.
10.2
610
1,500
300
360
300
14.5
Mean
cone.
10.1
620
1,600
400
400
330
18.7
TABLE 5-6. CONVENTIONAL AND NONCONVENTIONAL POLLUTANT
CONCENTRATIONS IN POWER LAUNDRY WASTEWATER5
me/1
Pollutant
PH
BODS
COD?
TOC
TSS
Oil and grease
Phosphorus
Number
14
8
11
4
11
9
6
Minimum
cone.
6.5
110
190
58
50
3
<0.05
Maximum
cone.
11.1
940
1,400
240
410
370
23.5
Median
cone.
9.6
210
5SO
160
230
52
4.0
Mean
cone.
9..4
340
660
150
220
110
7.3
38
-------
cause for the variable pollutant concentrations noted above. However, BOD^, TSS,
and oil and grease loadings are also influenced by the particular types of "linen
supply work" performed. For example, the wastewaters from laundries washing a
high percentage of aprons, tablecloths, napkins, etc., used in restaurants contain
higher levels of oil and grease than do wastewaters from laundries washing a high
percentage of sheets or towels used in hotels.
Laundering chemicals were not considered as a major source of BOD^, TSS, or
oil and grease in industrial laundry wastewaters. However, detergents, soaps,
starches and other organic process chemicals contribute BOD to the wastewater;
soap is also a source of oil and grease. These pollutant sources are considerably
more significant in comparison to soil loading in the linen supply subcategory than in
the industrial laundry subcategory. Variable oil and grease concentrations in linen
laundry wastewaters are at least partially attributable to the fact that some
establishments use soap while others use synthetic detergents.
5.2.1.3 Power Laundries, Family and Commercial
Table 5-6 summarizes the conventional and nonconventional pollutant data
obtained for 14 power laundries. Comparing these data to the data shown in Tables
5-3 and 5-5, it appears that power laundry wastewaters typically contain lower
concentrations of BOD^, COD, TOC, suspended solids and oil and grease than either
industrial laundry or linen supply wastewaters. Much narrower ranges in concentra-
tion are also indicated.
Both of these observations are related to the types of customers serviced by
power laundries. Family wash has been traditionally the largest source of bjsiness
for these establishments, but many power laundries now service commercial
businesses, and service organizations. However, very little "industrial-type" work is
performed; hence, the soil loadings on garments washed in these laundries tend to be
light.
The median and mean concentrations of BOD^, COD, TOC, TSS, oil and grease
and phosphorus shown in Table 5-6 are comparable to the levels at which these
pollutants are found in domestic sewage. However, power laundry wastewaters tend
to be more alkaline than does domestic sewage due to the use of alkali in the
washing process. In 14 plant effluents for which data were available, the median
and mean pH values were 9.6 and 9.4, respectively.
5.2.1.4 Diaper Services
Table 5-7 summarizes the conventional and nonconventional pollutant data
obtained for 9 diaper service effluents.
In terms of BOD^, COO and oil and grease, these wastewaters appear to be
roughly equivalent to the wastewater discharged by power laundries. Higher
concentrations of TOC and phosphorus and lower concentrations of suspended solids
were present in the diaper service effluents, but these observations are based on
limited data and may not represent the entire industry.
Median and mean concentrations of all pollutants listed in Table 5-7, excluding
pH are roughly comparable to the levels at which these pollutants are present in
domestic wastewaters.
39
-------
TABLE 5-7. CONVENTIONAL ANL NONCONVENTIONAL POLLUTANT
CONCENTRATIONS IN DIAPER LAUNDRY WASTEWATERS
me/1
Pollutant
pH
BODS
COD5
TOC
TSS
Oil and grease
Phosphorus
Number
9
5
8
2
8
7
2
Minimum
cone.
7.0
160
230
3SO
80
19
15.5
Maximum
cone.
11.0
560
1,100
400
280
330
30.0
Median
cone.
10.4
240
520
390
130
85
22.8
Mean
cone.
9.9
320
580
390
150
120
22.8
TABLE 5-8. CONVENTIONAL AND NONCONVENTIONAL POLLUTANT
CONCENTRATIONS IN COIN-OPERATED LAUNDRY
WASTEWATERS
me/1
Pollutant
pH
BOD,
COr/
TOC
TSS
Oil and grease
Phosphorus
Number
29
31
18
1
28
13
2
Minimum
cone.
6.4
17
73
68
17
< 2
1.5
Maximum
cone.
9.2
500
930
68
630
74
18.0
Median
cone.
8.0
120
270
68
85
23
9.8
Mean
cone.
7.9
140
340
68
140
26
9.8
40
-------
5.2.1.5 Coin-Operated Laundries
Table 5-8 summarizes the conventional and nonconventional pollutant data
obtained for 33 coin-operated laundries. Based on the median and mean pollutant
concentrations shown in this table, coin-op wastewaters are less heavily polluted
than are the wastewaters from any of the four commercial laundry subcategories
previously discussed and they are comparable to low-strength domestic wastewatcrs.
Lightly-soiled family wash accounts for nearly all of the business at these
establishments.
5.2.1.6 Carpet and Upholstery Cleaners
Table 5-9 presents conventional and nonconventional pollutant data for one
carpet-cleaning plant sampled during the course of this study. Except for
phosphorus, all pollutant concentrations are comparable to or less than the median
and mean pollutant loadings shown for coin-operated laundry wastewaters in Table
5-8.
5.2.1.7 Dry-Cleaning Plants
Table 5-10 presents conventional and nonconventional pollutant data for one
commercial dry-cleaning plant using perchloroethylene solvent. All pollutant
concentrations are extremely low -- in the range of or below analytical detection
limits. The source of process wastewater at this plant was condensate from the
steam regeneration of carbon columns used for solvent vapor emission control.
5.2.1.8 Car Washes
Table 5-11 summarizes the conventional and nonconventional raw waste
pollutant data obtained for 6 rollover and 6 wand and 17 tunnel type car washes.
For purposes of comparison, Table 5-12 presents separate tunnel car wash data for
both wash and rinse wastewater. Based on median and mean pollutant
concentrations shown in these tables, wand type car wash wastewaters are more
heavily polluted than wastewaters from tunnel types and rollover type car wash
wastewater are the least polluted.
The median and mean concentrations of BOD5, TOC and phosphorus were
below the typical concentration range of pollutants present in domestic wastewater.
COD, T5S and oil and grease concentrations were equivalent to or below the
concentration in domestic sewage.
5.2.2 Toxic Pollutants
Table 5-13 lists the 129 toxic substances that are classified by the EPA as
toxic pollutants. The list includes 13 metals, cyanide, asbestos and 114 organic
compounds. In this study, auto and other laundry wastewaters were sampled and
analyzed for each of these pollutants except asbestos. Data were also collected for
total phenol and are included in this section. Although total phenol is not a specific
toxic pollutant, it is a convenient surrogate for the various phenolic compounds
listed as toxic pollutants.
41
-------
TABLE 5-9. CONVENTIONAL AND NONCONVENTIONAL POLLUTANT
CONCENTRATIONS IN WASTEWATER FROM ONE
CARPET-CLEANING PLANT
Pollutant concentration, mg/1
pH 7.1
BOD, 99
COD5 280
TOC *6
TSS 100
Oil and grease 19
Phosphorus 29.0
TABLE 5-10. CONVENTIONAL AND NONCONVENTIONAL POLLUTANT
CONCENTRATIONS IN WASTEWATER FROM ONE
DRY-CLEANING PLANT
PoJJutant concentration, mg/1
PH
BOD,
CODT
TOC
TSS
Oil and grease
Phosphorus
7.2
<2
8
2
3
<2
0.2
42
-------
TABLE Ml.
CONVENTIONAL AND NONCONVENTIONAL POLLUTANT
CONCENTRATIONS IN ROLLOVER, WAND AND TUNNEL
TYPE CAR WASH WA5TEWATERS.
Pollutant
Number3 Minimum Maximum Median Mean
Rollovers
pH
BOD5
COD
TOC
TSS
Oil and grease
Phosphorus
Wands
pH
BOD5
COD
TOC
TSS
Oil and grease
Phosphorus
Tunnels
PH
BOD5
COD
TOC
TSS
Oil and grease
Phosphorus
Concentrations (mg/1)
6
6
4
4
6
6
*
6
6
4
4
6
6
4
4
17
16
16
17
17
16
6.2
8.0
102
24
30
6.0
0.25
6.4
29
167
29
106
20
0.8
7.5
< 6.0
61
16
36
5.7
0.38
7.7
132
254
173
576
188
1.9
8.3
220
1120
160
2970
404
3.2
9.0
147
517
169
848
239
24
7.7
20
135
31
158
9.4
0.41
7.4
69
238
79
659
90
2.8
8.7
42
178
31
101
20
1.9
7.3
37
156
65
199
45
0.74
7.5
90
442
86
929
126
2.4
8.5
51
216
52
165
38
3.2
Number of data points
43
-------
TABLE 5-12.
CONVENTION-.l -.ND NONCONVENTIONAL POLLUTANT
CONCENTRATE \5 IN TUNNEL TYPE CAR WASH RAW
WASH AND RINSE WASTEWATERS
Concentration (me/1)
Pollutant
Numbera Minimum Maximum Median Mean
Raw Wash
pH
BOD5
COD
TOC
T5S
Oil and grease
Phosphorus
Raw Rinse
pH
BOD5
COD
TOC
TSS
Oil and grease
Phosphorus
15
15
14
14
15
15
14
13
13
12
12
13
13
12
7.1
18
96
16
28
4.8
0.4
7.3
8.0
64
11
19
5.8
< 0.2
10
191
653
210
882
655
27
9.4
153
376
100
153
114
18.0
8.0
45
204
66
121
17
2.3
8.0
53
166
27
54
43
0.92
8.3
59
261
70
195
68
4.0
8.1
59
184
32
62
39
2.8
Number of data points
44
-------
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116.
117.
IIS.
111.
170.
171.
172.
123.
171.
17).
176.
177.
121.
129.
•cndasull.iii and iiirlalralilci
a-nidi»iillaii-Alpna
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rmlojiill.in uillalc
•rndfin and metaliolilci
rndnn
cmtr in aUleliyde
•liclpl.irlilor and mclaliolilei
ln:|it, ii lilur
lirpi.iclilur cpniide
•lir,.M liluirx yi lolioane (all i joiner i)
.i-IUIl -Alpha
b-hllC.-lli 13
K-ltlli: Iliiidjiwl-Camma
d-HIIO-rVha
•pnlycliliwiiiiilrd liiplicnjrU (I'CU'l)
I'CI^- 1?*? ( Vochlor 12^2)
l'CI«-l2>li (Arorlilor 17 Id)
rcit-1771 (Aroclilor 1771)
l'(.^-l7)7(Ar«ililor 12)7)
l>rh-|7«aCI>-IOI6 (Aroclilor 1016)
•iDLipU-iie
••iniiiniHiy (luldl)
•aiu-iuc Iliildl)
'.ivbnloi (llbruusl
•In-ryllinin liolal)
•railiiiiuni (lolal)
•clii nin liolal)
•tnp|H-r (i«ul)
• i). innk (inial)
•k-ad (loull
•ini.ii.uiy (loial)
*nirkcl (loltil)
•»r|i-iiiinn (lolal)
•lil»cr (lolal)
•llullium (lolal)
•zinc lioi.il)
•7,1,7,8-lclinclilorodibcruo-p-
'*C rninnrtirfirff mn
t at liMed in ilic content
B1. pjricne
dcc're.
(»ndeicd02/0ti/9lilifc CR 10771
"•nclclrd Ol/Oi/SI, «b Fit 2766
-------
Several toxic pollutants are either known or suspected to be present in various
laundering qhemicals. These include:
o Zinc, present as zinc silicofluoride in sours and as zinc-2-pyridinethio in
germicides
o Phenolic compounds, several of which are used in germicides,
bacteriostats and dust treating compounds and as detergent additives
o Naphthalene, a constituent of naphtha-based oils used for dust treating
purposes (16) and various naphtha-based solvents
o Benzene, which is a major precursor of alkyl benzene sulfonate
detergents and which may be present in aromatic solvents used in the
industry
o Miscellaneous aromatic compounds present in petroleum-based solvents
o Poiynuclear aromatic hydrocarbons, which may be present in stilbene-
based fluorescent whiteners as manufacturing by-products (16)
o Perchloroethylene, or "perc", which is the most commonly used dry-
cleaning solvent
o Methylene chloride and trichloroethylene, which are major constituents
of at least one commercial solvent formulation
o Mercury, which is present at trace levels in caustic soda
Indirectly, chlorine bleaches may also contribute to toxic pollutant loadings in
wastewater by converting relatively harmless low-molecular-weight organics to
chlorinated organic substances.
These and other toxic pollutants may be present in the soil on the articles or
vehicles being washed, as well. This is likely to occur particularly in the industrial
laundry subcategory, due to the nature of the workload handled by these
establishments.
In the following paragraphs, specific toxic pollutants are discussed with regard
to their sources and their toxicity to humans and animals.
The toxic metals found most frequently and at the highest concentrations are
lead, zinc, copper and chromium. Because the raw waste concentrations observed
for these four metals are considered significant, lead, zinc, copper and chromium
have been selected for regulation. Other toxic metals are excluded from regulation
under Paragraph 8(a)(iii) of the Consent Decree because they are present only in
trace amounts and are neither causing or likely to cause toxic effects or because
they are present in amounts to small to be effectively reduced.
Lead - Lead is used in various solid forms both as a pure metal and in several
compounds. Lead appears in some natural waters, especially in those areas where
mountain limestone and galena are found and can also be introduced into water from
lead pipes by the action of the water on the lead.
Lead is a toxic material that is foreign to humans and animals. The most
common form of lead poisoning is called plumbism. Lead can be introduced into the
body from the atmosphere containing lead or from food and water. Lead cannot be
easily excreted and is cumulative in the body over long periods of time, eventually
causing lead poisoning with the ingestion of an excess of 0.6 mg per day over a
period of years. It has been recommended that 0.05 mg/1 lead not be exceeded in
public water supply sources.
46
-------
Fish and other marine life have had adverse effects from lead and lead salts in
their environment. Experiments have shown that small concentrations of heavy
metals, especially of lead, have caused a film of coagulated mucus to form first
over the gills and then over the entire body probably causing suffocation of the fish
due to this obstructive layer. Toxicity of lead is increased with a reduction of
dissolved oxygen concentration in the water.
Zinc - Occurring abundantly in rocks and ores, zinc is readily refined to a
stable~~pure metal and is used extensively as a metal, an alloy, and a plating
material. In addition, zinc salts are also used in paint pigments, dyes, and
insecticides. Many of these salts (for example, zinc chloride and zinc sulfate) are
highly soluable in water; hence, it is expected that zinc might occur in many
industrial wastes. On the other hand, some zinc salts (zinc carbonate, zinc oxide,
zinc sulf ide) are insoluble in water, and consequently, it is expected that some zinc
will precipitate and be removed readily in many natural waters.
In soft water, concentrations of zinc ranging from 0.1 to 1.0 mg/1 have been
reported to be lethal to fish. Zinc is thought to exert its toxic action by forming
insoluble compounds with the mucous that covers the gills, by damage to the gill
epithelium, or possibly by acting as an internal poison. The sensitivity of fish to
zinc varies with species, age, and condition, as well as with the physical and
chemical characteristics of the water. Some acclimatization to the presence of the
zinc is possible. It also has been observed that the effects of zinc poisoning may not
become apparent immediately so that fish removed from zinc-contaminated to zinc-
free water may die as long as *fS hours after the removal. The presence of copper in
water may increase the toxicity of zinc to aquatic organisms, while the presence of
calcium or hardness may decrease the relative toxicity.
Concentrations of zinc in excess of 5 mg/1 in public water supply sources cause
an undesirable taste which persists through conventional treatment. Zinc can have
an adverse effect on man and animals at high concentrations.
Chromium - Chromium is an elemental metal usually found as a chromite
The metal is normally processed by reducing the oxide with aluminum.
Chromium and its compounds are used extensively throughout industry. It is
used to harden steel and as an ingredient in other useful alloys. Chromium is also
used in the electroplating industry as an ornamental and corrosion resistent plating
on steel and can be used in pigments and as a pickling acid (chromic acid).
The two most prevalent chromium forms found in industry wastewaters are
hexavalent and trivalent chromium. Chromic acid used in industry is a hexavalent
chromium compound which is partially reduced to the trivalent form during use.
Chromium can exist as either trivalent or hexavalent compounds in raw waste
streams. Hexavalent chromium treatment involves reduction to the trivalent form
prior to removal of chromium from the waste stream as a hydroxide precipitate.
Chromium, in its various valence states, is hazardous to man. It can produce
lung tumors when inhaled and induces skin sensitizations. Large doses of chromates
have corrosive effects on the intestinal tract and can cause inflamation of the
kidneys. Levels of chromate ions that have no effect on man appear to be so low as
to prohibit determination to date. The recommendation for public water supplies is
that such supplies contain no more than 0.05 mg/1 total chromium.
47
-------
The toxicit of chromium salts to fish and other aquatic life varies widely with
the species, temperature, pH, valence of the chromium and synergistic or
antagonistic effects, especially that of hard water. Studies have shown that
trivalent chromium is more toxic to fish of some types than hexavalent chromium.
Other studies have shown opposite effects. Fish food organisms and other lower
forms of aquatic life are extremely sensitive to chromium and it also inhibits the
growth of algae.
•Copper - Copper is an elemental metal that is sometimes found free in nature
and is found in many minerals such as cuprite, malachite, asurite, chalcopyrite, and
bornite. Copper is obtained from these ores by smelting, leaching, and electrolysis.
Significant industrial uses are in the plating, electrical, plumbing, and heating
equipment industries. Copper is also commonly used with other minerals as an
insecticide and fungicide.
Traces of copper are found in all forms of plant and animal life, and it is an
essential trace element for nutrition. Copper is not considered to be a cumulative
systemic poison for humans as it is readily excreted by the body, but it can cause
symptoms of gastroenteritis, with nausea and intestinal irritations, at relatively low
dosages. The limiting factor in domestic water supplies is taste. Threshold
concentrations for taste have been generally reported in the range of 1.0 - 2.0 mg/1
of copper while concentrations of 5.0 to 7.5 mg/1 have made water completely
undrinkable. It has been recommended that the copper in public water supply
sources not exceed 1 mg/1.
Irrigation waters containing more than minute quantities of copper can be
detrimental to certain crops. The toxicity of copper to aquatic organisms varies
significantly, not only with the species, but also with the physical and chemical
characteristics of the water, including temperature, hardness, turbidity, and carbon
dioxide content.
Copper concentrations less than 1 mg/1 have been reported to be toxic,
particularly in soft water, to many kinds of fish, crustaceans, mollusks, insects,
phytoplankton and zooplankton. Concentrations of copper, for example, are
detrimental to some oysters above 0.1 mg/1. Oysters cultured in sea water
containing 0.13-0.5 mg/1 of copper deposted metal in their bodies and become unfit
as a food substance.
Others - Antimony, arsenic, cadmium, mercury, nickel, silver, and cyanide
were all frequently detected in industrial laundry wastewaters, but generally at
much lower concentrations than lead, zinc, copper, or chromium. Antimony,
arsenic, and nickel were found in one or more wastewater samples at concentrations
greater than 1.0 mg/1, but the median concentration of each of these metals was
below 0.5 mg/U Soil on the articles being laundered is considered to be the major
source of these contaminants since none of them were found at comparable median
levels in wastewaters from plants in the other industry subcategories.
The organic priority pollutants found most consistently in laundry wastewaters
were toluene, bis(2-ethylhexyl) phthalate, tetrachloroethylene, naphthalene,
chloroform, and benzene.
Toluene - Toluene is toxic to man, animal, and aquatic life; however, it is
apparently not inhibitory to POTW operation. Toluene at the 500 mg/J level has no
applicable effect on sludge digestion processes
48
-------
Toluene is widely used in the chemical industry as a precursor for benzene and
other intermediates, as a solvent for surface coatings, adhesives, inks, paints, etc.,
and as a gasoline additive. It may be present in various aromatic solvents used by
the laundry industry, especially by industrial laundries to aid in oil and grease
removal.
Bis(2-ethylhexyl) phthalate - Bis(2-ethylhexyl) phthalate is widely used as a
plasticizer in polyvinyl chloride plastics to impart flexibility. It is also used as a
pesticide carrier, in cosmetics, fragrances, industrial oils, and insect repellents to a
lesser extent. Leaching of textile coating formulations is a potential source of
bis(2-ethylhexyl) phthalate in laundry waste waters.
Perchloroethylene - Perchloroethylene is used in metal degreasing
applications, as a scouring and sizing agent in the textile industry, and as a raw
material in the production of C2 fluorocarbons. However, it is most widely used as
a dry cleaning solvent. This is the most probable source of perchloroethylene in
laundry wastewaters.
Perchloroethylene is toxic to man and other animals, and has been implicated
as a carginogen in mice. Very limited data are available on the fate and potential
adverse effects of this compound in POTW's; however, one investigator reports that
perchloroethylene is inhibitory to the anaerobic sludge digestion process at
concentrations of 20 mg/1 or higher (47,48).
Naphthalene - Naphthalene is known to be toxic to man, other animals, and a
number of fish species. At concentrations of 2500 mg/1, naphthalene is toxic to
sewage treatment plant organisms (49).
Naphthalene is used in the production of phthalic anhydride; insecticides; dye,
pigment, and rubber processing chemical intermediates; leather tanning agents; and
moth repellents. Naphthalene is also present in naphtha-based solvents and dust
treating oils used by the laundry industry, particularly by industrial laundries.
Chloroform - Chloroform (CHC^J is toxic to man, other mammals, and fish
and is a suspected carcinogen in animals. Apparently, chloroform is not inhibitory
to activated sludge processes (49). However, various investigators have reported
that chloroform is inhibitory to anaerobic digestion processes at concentrations (in
sludge) ranging from 0.1 to 20 mg/1 (22,50-53).
Chloroform is used in the production of fluorocarbon refrigerants, and as a
solvent for fats, oils, rubbbers, alkaloids, waxes, and resins. Chloroform is
ubiquitous in city water supplies, due to chlorination of low molecular weight
organics in water treatment processes.
Benzene - Benzene is toxic to man, other mammals, and fish, and is a
suspected carcinogen in man. Apparently, benzene has little or no adverse effect on
the activated sludge process, although it can seriously retard sludge digestion at a
concentration of 1000 mg/1 (47).
Benzene is primarily used by the chemical industry as a raw material for
ethylbenzene, cumene, cyclohexane, aniline, chlorobenzenes, maleic anhydride,
synthetic detergents, and other chemicals. It has been widely used as a solvent in
the past, but this market has been phased out to a large extent due to the suspected
carcinogenicity of benzene.
49
-------
Others •• Fourteen other organic c .o-::y pollutants were detected in at least
one industrial laundry wastewater at co,-.-_?-!iraTions greater than 0.1 mg/1. These
include carbon tetrachloride, 1,1,1-trichioroethane, dichlorobenzenes (ortho-and
para isomers), 2,4-dimethylphenoJ, ethylbenzene, methyJene chloride, isophorone, N-
nitrosodiphenylamine, phjenol, butyl benzyl phthalate, di-n-butyl phthalate, di-n-
octyl phthalate, anthracene, and trichloroethylene. The frequency and maximum
concentration at which each of these compounds was detected are shown in the
following subsections.
Other than the six compounds discussed in the preceding pages, no organic
priority pollutants were found at more than 0.1 mg/1 in linen supply, power laundry,
diaper service, carpet cleaning, or coin-operated laundry wastewaters.
In the following pages, toxic pollutant concentration data are presented for
wastewaters from each industry subcategory. Priority pollutant concentrations in
auto and other laundry water supplies are also identified to provide an indication of
the background levels at which the various compounds are normally present. All
organic toxic pollutant data are based on sampling and- analysis performed in
conjunction with the Effluent Guidelines study and the results of an earlier study
(54). Metals, cyanide and total phenol data were also obtained from industry survey
and trade association reports, Chicago MSD monitoring reports and literature
sources (11,55,56).
3.2.2.1 Industrial Laundries
Table 5-14 summarizes the toxic pollutant data collected for the industrial
laundry subcategory. It identifies the maximum, median and mean concentrations at
which each pollutant was found and the number of plant wastewaters in which these
pollutants were detected as well as the daily load of each pollutant in kg/day. For
purposes of comparison, Table 5-15 presents similar data for laundry water supply
samples collected and analyzed over the course of this program.
Nine of the thirteen toxic pollutant metals were found in more than 50% of
the industrial laundry effluents. Lead, zinc, chromium and copper were detected in
virtually all of the samples and were present at higher concentrations than any of
the other metals. The median concentrations of lead, zinc, copper and chromimum
were 4.6 mg/1, 3.0 mg/1, 1.5 mg/1 and 0.47 mg/1, respectively. The corresponding
mean concentrations of these metals were 4,5 mg/i, 3.0 mg/1 and 1.7 mg/1. Nickel,
antimony, cadmium, arsenic, silver and mercury were also detected in the majority
of the plant wastewaters, but generally at much lower concentrations.
With the possible exception of zinc and mercury, the presence of these metals
in industrial laundry wastewater is largely attributable to soil on the articles being
washed. For example, several industrial laundry owners surveyed during the course
of this study identified print shop towels as a major source of lead in their
wastewaters.
Cyanide and total phenols were detected in most of the laundry wastewaters.
With few exceptions, however, cyanide was found only at low levels. The median
cyanide concentration was 0.057 mg/1, which is in the range of the detection limit.
The mean cyanide concentration was 0.13 mg/1. Somewhat higher phenol
concentrations were noted, probably due to the presence of these compounds in
various laundry chemicals and possibly due to soil contamination since phenol and its
derivatives are widely used in industry.
50
-------
TABLE 3-l». TOXIC POLLUTANT CONCENTRATIONS AND LOADINGS IN INDUSTRIAL
LAUNDRY WA5TEWATEK
Pollutant
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Cyanide (Total)
Phenols (Total)
Benzene
Carbon Tecracfilonde
1,1, 1-Tr ichloroe thane
2-Cliloronaphthalene
Chloroform
2-Chloropnenol
Dichtoro&enzenes
2,4-Dichlorophenol
2,4-Dimetriylphenol
dtliylbenzeiie
Biil2-cnioroiiopropyl) ether
BisU-ciiloroeUoxy) methane
Mutnylene chloride
Uicniurobromoine thane
TriUilorofluoromelhane
liOptiorone
Naphthalene
Z-Nitrcphenol
N-NJ irosodjphenyJamjne
Phenol
Uis(2-ethylhe»yl) phihaiate
Butyl benzyl phihaiate
Di-n-butyl phthdlate
Di-n-octyl phtnaJate
Anihracene/phenanthrene
Teiracnloroethylene
Toluene
TncMoroethylene
Number*
7/8
6/6
7/7
a/8
S/S
8/8
»/3
K/8
1/2
2/
-------
TABLE 5-15. TOXIC POLLUTANT CONCENTRATIOf IN LAUNDRY
WATER SUPPLIES
Maximum
Pollutant
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Phenol (total)
Benzene
Chlorobenzene
1,1,1 -Tr ichJoroethane
2,4,6-Trichlorophenol
Chloroform.
2-Chlorophenol
Dichlorobenzenes
1,1-Dichloroethylene
1 ,2-tr ans-Dichloroethylene
2,4-Dichlorophenol
Ethylbenzene
Methylene chloride
Dichlorobromomethane
Trichlorofluormethane
Chlorodibromomethane
Isophorone
Naphthalene
Phenol
Bis(2-ethylhexyl)phthalate
Butyl benzyl phthalate
Di-n-butyl phthalate
Di-n-octyl phthalate
Diethyl phthalate
Dimethyl phthalate
Anthracene /phenanthrene
Tetrachloroethy lene
Toluene
Trichloroethylene
a Ratio indicates the
Number*
7/29
4/29
9/31
18/31
23/31
12/31
10/31
6/31
2/28
3/31
2/28
22/31
13/29
4/33
1/33
5/33
1/36
22/33
1/36
2/36
4/33
1/33
2/36
2/33
16/33
15/33
2/33
8/33
1/36
2/36
5/36
25/36
3/36
20/36
3/36
7/36
3/36
1/36
15/33
13/33
4/33
number of samples
found as compared to the total number of
D Blanks indicate valu
IBS below analytical
cone.
0.027
0.011
0.020
0.080
0.30
0.10
0.008
0.060
0.004
0.030
0.006
0.30
0.032
0.040
0.002
0.14
<0.010
0.14
<0.010
<0.010
<0.010
"0.049
<0.010
"0.005
14.7
0.088
0.13
0.020
<0.010
<0.010
<0.010
"1.2
<0.010
"0.014
<0.010
<0.010
<0.010
<0.010
"0.42
0.14
<0.010
mg/l
Median
cone.''
<0.010
<0.001
<0.002
0.010
0.030
<0.020
<0.0001
<0.005
<0.001
<0.005
<0.005
0.094
<0.002
0.012
<0.010
<0.010
on which the specific
samples
detectic
analyzed.
>n limits. Api
Mean
cone.'1
<0.010
<0.001
<0.002
0.016
0.048
<0.020
<0.0004
0.006
<0.001
<0.005
<0.005
0.072
0.006
<0.002
<0.005
< 0.000 3
<0.025
<0.0003
< 0.0006
< 0.0006
0.0003
<0.60
0.009
0.005
<0.002
<0.0003
< 0.0006
-------
A total of 28 specific organic toxic pollutants were detected in one or more of
the industrial laundry effluents analyzed for these substances. Most of the
compounds fall into one of four categories: aromatic hydrocarbons and their
chlorinated derivatives, low-molecular-weight halogenated aliphatics, phenol and
derivatives thereof and phthalate esters.
Five organic toxic pollutants were detected in more than 50% of the
wastewater samples: toluene, perchloroethylene, ethylbenzene, chloroform and
phenol.
' Naphthalene, bis(2-ethylhexyl) phthaJate and methylene chloride were also
found in 50% of the plant effluents.
Obviously, organic toxic pollutant loadings vary considerably from one
industrial laundry to another. Perchloroethylene concentrations, for example,
ranged from 0.001 mg/1 to 0.88 mg/1. One factor affecting this variability is the
amount of "perc" dry cleaning performed by different industrial laundries. For other
pollutants such as benzene, methylene chloride, naphthalene, trichloroethylene and
toluene3, concentrations in wastewater may also be at least partially related to the
use of various process chemicals. However, these and other organic toxic pollutants
found in industrial laundry waste waters are widely used in the chemical and
manufacturing industries; hence, soil on the articles being laundered is a potential
major source of wastewater contamination and pollutant concentration variability.
The types of garments being washed may also influence the concentrations of
bis(2-ethylhexyl) phthalate and related esters in laundry wastewaters. The
phthalates are used in many textile coating formulations and could leach from these
fabrics into the wastewater. Vinyl mats, which are high-volume items in the
industrial laundry subcategory, are particularly likely sources of phthalate esters.
Bis (2-ethylhexyl) phthalate is the most widely used plasticizer in polyvinyl chloride
products.
The use of chlorine bleach is a probable source of many of the low-molecular-
weight chlorocarbons listed in Table 5-1
-------
TABLE 3-1*. TOXIC POLLUTANT CONCENTRATIONS AND LOADINGS
IN UNEN LAUNDRY WASTSWATERS
m«/t
Maximum Median
Pollutant
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Cyanide
Phenol (tool)
1,1,1-Trichloroethane
Chloroform
2,4-Dichlorophenol
Ethylbenzene
Methylene chloride
Naphthalene
Phenol
Bis(2-ethylhexyU phihaJate
Butyl benzyl phtrtalate
Di-n-outyl phthalate
Di-n-octyt phthaiate
Diethyl phthatate
Dimethyl phthalate
Anthracene/pnenanthrene
Perchloroethylene
Toluene
Number*
5/7
4/7
3/36
20/36
13/13
27/36
12/36
19/36
1/7
ft/7
1/7
36/37
J/7
7/7
1/3
»/3
2/3
l/J
2/3
1/3
V3
ft/3
2/3
3/3
1/3
1/3
1/3
3/3
2/3
*/5
* Ratio indicate* trie number of samples in
cone.
0.037
0.026
0.12
0.93
3.3
3.0
0.031
0.30
0.003
0.047
0.006
2.3
0.077
0.26
<0.010
"0.18
<0.010
"0.011
0.092
1.2
0.030
9.0
<0.010
"0.026
<0.003
<0.<303
?0.003
~0.016
<0.010
"0.099
cone.0
0.007
0.006
<0.002
0.0»6
0.21
0.24
<0.0002
0.02S
<0.002
O.OQ2
<0.003
0.70
0.033
0.12
0.020
<0.010
"0.16
<0.010
-------
mean concentrations of both pollutants u.ers considerably lower in the linen laundry
wastewaters. No more than trace level: of cyanide were detected in any of the
samples.
Sixteen organic toxic pollutants were detected in at least one of five Linen
laundry effluents analyzed for these compounds. With few exceptions, these were
the same compounds found in the industrial laundry wastewaters. Much lower
concentrations were observed in the linen supply effluents, however; oniy bis(2-
ethylhexyi) phthaiate, naphthalene and chloroform were found in any of the
effluents at concentrations greater than 0.1 mg/1.
5.2.2.3 Power Laundries, Family and Commercial
Table 5-17 summarizes the toxic pollutant data collected for establishments in
the power laundry subcategory. Only five of the toxic pollutant metals (antimony,
zinc, lead, copper and chromium) were present in any of the effluent samples at
concentrations greater than 0.1 mg/1. Except for zinc and copper, median
concentrations of these metals were all much less than 0.1 mg/1, in the range of
detection limits. In general, the concentrations of these pollutants were lower than
the concentrations shown in Table 5-16 for linen supply wastewaters.
Phenols (total) were detected in each of five power laundry effluents analyzed
at concentrations up to 0.97 mg/1; however, the median phenol concentration was
only 0.073 mg/1. Cyanide was detected in only one of five effluent samples at
extemely low concentration.
Twenty-five organic toxic pollutants were present in one or more of the four
wastewaters analyzed for these compounds, but only bis(2-ethy!hexyl) phthaiate and
perchloroethylene were found in any of the samples at concentrations greater than
0.1 mg/1.
5.2.2.4 Diaper Services
Table 5-18 summarizes the toxic pollutant data collected for the diaper
service subcategory. Seven of the toxic pollutant metals were detected in at least
one sample, but only zinc was present at more than 0,1 mg/! in any of the samples.
Zinc concentrations ranged from 1.5 mg/1 to 10.0 in five diaper laundry
wastewaters, possibly due to the use of zinc silicofluoride sours,
No other toxic pollutants were found at significant levels, which is
understandable in light of the types of soil present on diapers.
5.2.2.5 Coin-Operated Laundries
Table 5-19 summarizes the toxic pollutant data obtained for three coin-
operated laundry wastewaters. Eight toxic pollutant metals, phenol (total) and 12
organic toxic pollutants were detected in at least one of these effluent samples, but
only zinc, total phenol and bis(2-ethylhexyl) phthaiate were present at
concentrations greater than 0.1 mg/1 in any of the samples. This attests to the
innocuous types and quantities of soil present on family-type wash, which accounts
for virtually 10096 of the coin-op business.
55
-------
TABLE 5-17. TOXIC POLLUTANT CONCENTRATIONS AND
LOADINGS IN POWER LAUNDRY VASTEWATCRS
Maximum
Pollutant
Antimony
Arsenic
Cadmium
Chromium
Capper
Lead
Mercury
Nickel
Sliver
line
Cyanide
Phenol (total)
1,1,1-TricMcroethane
Chloroform
2-CMoropnenol
Dicnlorooenzenes
2,4-Dichlorophenoi
2,4-Oimethyiohenol
Fluoranthene
Methylene chloride
Naphthalene
Pencachlorophenol
Phenol
Bis(2-ethylhexyl) phthalate
Butyl benzyl phSialats
Di-o-butyl pnthalats
Di-n-ocryl phthalate
Diethyt phthaiate
Antnracene/phenanthrene
Pyrene
PtrchloroethyLene
Toluene
TriCTioroetfiylene
Chlordane
4f»'-DOT
«,»'-ODE
Heptachlor
Number*
5/6
2/6
3/5
6/7
7/7
6/7
5/8
4/7
2/7
6/6
1/3
5/5
1/H
J/»
2/*
I/"
1/&
2/»
I/"
I/ft
2/4
2/u
3/o
ft/4
ft/4
»/a
3/ft
I/ft
2/ft
1/4
3/4
I/ft
2/ft
l/»
I/ft
1/4
l/»
• Ratio indicates the number of samples in
cone.
0.37
0.020
0.046
0.36
0.37
0.43
0.003
0.050
O.OOS
0.5*
0.02S
0.97
0.002
0.041
O.C01
-------
TABLE 5-18. TOXIC POLLUTANT CONCENTRATIONS AND LOADINGS IN DIAPER
LAUNDRY WASTEWATERS
Ul
Pollutant
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Zinc
Cyanide
Phenol (total)
Chloroform
Phenol
Number3
2/H
1/5
'»/'*
2/'f
1/3
2h
5/5
1/2
3/3
1/1
l/l
Maximum
cone.
O.O'iO
0.022
0.10
0.035
0.0009
0.10
10.0
0.060
O.OcSO
0.072
Q.03S
rriR/l
Median
conc.b
<0.006
<0.010
O.OKO
<0.02<»
<0.0009
<0.035
'(.0
<0.050
0.036
~ ~ m*
Mean
conc.b
O.OM
<0.010
O.QTi
<0.02';
<0.0009
<0.035
5.7
<0.050
0.0'JO
...
kR/day
avg/facility
0.0018
<0.016
0.013
<0.0038
<0.00014
<0.0056
0.91
<0.008
0.0064
a
b
Ratio indicates the number ol samples in which the specific pollutant was found as compared to the
total number of samples analyzed,
IManks indicate values below analytical detection limits. Appendix A lists representative detection
limits (or each organic priority pollutant.
-------
TABLE 5-19.
TOXIC POLLUTANT CONCENTRATIONS AND LOADINGS
IN COIN-OPERATED LAUNDRY WASTEWATERS
Ul
CO
Pollutant
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Zinc
Phenol (total)
Benzene
Chloroform
1,1-Dichloroethylcne
1 ,2-trans-Dichlorocthylene
Mcthylene chloride
nichlorobromomethane
Chlorodibrornorncihane
llis(2-ethylhcxyl) phlhulate
Oi-n-butyl phtha'.ate
Diethyl phthalnte
Perchlorocthylene
Toluene
Number3
2/3
1/3
1/3
1/3
3/3
7/3
2/3
3/3
1/3
1/3
2/3
1/3
1/3
1/3
1/3
1/3
2/2
1/2
1/2
1/3
1/3
Maximum
cone.
0.016
0.011
0.023
0.005
0.070
0.072
0.002
0.67
0.30
0.014
0.070
0.003
0.005
0.006
0.019
0.012
0.8'»
0.055
0.025
0.025
0.001
TT1K/I
Median
conc.b
0.013
<0.010
<0.002
<0.005
0.070
0.036
0.002
0.16
0,002
<0.020
0.80
0.028
0.012
Mean
cone.'1
0.010
<0.010
O.OOS
<0.005
0.067
0.036
0.001
0.31
0.10
0.005
0.030
0.002
0.006
0.004
0.80
0.028
0.012
0.008
0.0003
kfi/day
avg/facility
0.00014
-------
5.2.2.6 Carpet and Upholstery Cleaners
Toxic pollutant data for one carpet-cleaning plant are shown in Table 5-20.
Zinc, copper, lead and tetrachloroethylene were the only pollutants found at a
concentration greater than 0.1 mg/1.
5.2.2.7 Dry-Cleaning Plants
Table 5-21 presents toxic pollutant data for two commercial dry-cleaning
plant wastewaters. Both of the plants use perchloroethylene solvent.
As expected, both wastewater effluents contained perchloroethylene.
However, the concentration of "perc" differed by more than an order of magnitude,
from 0.2 mg/1 to 58.6 mg/1, in the two effluents. Seventeen other organic toxic
pollutants were detected in one of the wastewater samples, but none was found in
both effluents.
Chlorinated ethanes, ethylenes and chloroform were the only toxic pollutants
other than "perc" that were found at concentrations greater than 0.05 mg/l.
5.2.2.8 Car Washes
Three tables present and summarize toxic pollutant data from the three types
of car wash facilities. Table 5-22 summarizes wand facilities, Table 5-23
summarizes rollover facilities and Table 5-24 summarizes tunnel facilities. These
tables present the maximum, median and mean concentrations of each toxic
pollutant found in the raw waste samples and the number of wastewater samples in
which these pollutants were detected as well as the daily load of each pollutant in
kg/day.
Lead and zinc were present in all samples fro-n each of the three types of
facilities. These toxic pollutant metals exhibited the highest concentrations
although the average ranged only from .5 mg/1 to 1.0 mg/1 for lead and QA mg/1 to
1.5 mg/1 for zinc. The only other metals of significance were copper and nickel
which were found in almost every sample. Their mean concentrations averaged less
than 0.2 mg/1.
Several toxic pollutant organics were found in the wastewaters from car
washes. No pollutant was present in concentrations greater than 1.0 mg/1, and
virtually all had mean concentrations below .05 mg/1. As with the conventional
pollutants, the wand type facilities had the highest number and concentrations of
pollutants.
5.3 DISCHARGE TYPES
Because auto and other laundry facilities are almost exclusively confined to
urban and suburban areas where their customers are located, more than 99 percent
of all facilities discharge to publicly owned treatment works (POTW). Table 5-25
lists the approximate number and percentage of direct dischargers in each
subcategory in comparison to the total number of .establishments. The reported
number of direct dischargers is based on NPDES permit applications under the SIC
code for each subcategory. The actual number may differ slightly. For example, a
follow-up telephone survey of industrial and linen supply direct dischargers revealed
that out of seven permit applications on file only one site remains a direct
discharger.
59
-------
TABLE 5-20. TOXIC POLLUTANT CONCENTRATIONS IN
WASTEWATER FROM ONE CARPET CLEANING
PLANT
Concentration
Pollutant mg/1
Antimony 0.00*
Arsenic 0.008
Chromium 0.050
Copper 0.20
Lead 0.10
Mercury 0.001
Zinc 0.60
Chloroform <0.010
Bis(2-3ethylhexyl) phthalate 0.02*
Di-n-butyl phthalate <0.013
Tetrachloroethylene 0.23
60
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TABLE 5-21. TOXIC POLLUTANT CONCENTRATIONS IN
DRY CLEANING PLANT WA5TEWATER5
Concentration,
Pollutant Plant 1 Plant 2
Copper
Lead
Phenol (total)
Benzene
Chlorobenzene
1,2-Dichloroethane
1,1,1 -Tr ichloroethane
1 , 1 ,2-Trichloroe thane
Chloroform
1 , 1 -Dichlor oethy lene
1 ,2-trans- Dichloroethy lene
Methylene chloride
Dichlorofaromomethane
Chlorodibromomethane
Naphthalene
Phenol
Bis(2-ethylhexyl) phthalate
Di-n-butyl phthalate
Diethyl phthalate
Perchloroethylene
Trichloroethylene
0.050
0.0*0
<0.005
0.030
<0.010
<0.010
-------
TABLE 3-22 TOXIC POLLUTANT CONCENTRATIONS AND LOADINGS IN WAND TYPE CAR
WASH RAW WASTED ATERS
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Oiromium
Copper
™ rr
Lead
Mercury
Nickel
Selenium
Silver
Thallium
line
Chloroform
Fluoranthene
Methylene chloride
Dichlorobromomethane
Trichlorofluoromethane
Chlorodibromometnane
Naphthalene
*-nitrophenol
2,4-dinitrophenol
Bis(2-«thylhe*yi) phthalate
Butyl benzyl phthalate
Di-n-outyl phthalate
Di-n-octyl phthalate
Benzo(a) anthracene
Benzo(a) pyrene
Benzo(k) fluoranthene
Anthacene
Phenanthrene
Pyrene
Trichloroethylene
Number*
2/2
3/6
1/6
6/6
6/6
4/4
6/6
4/6
6/6
0/6
0/6
0/6
6/6
1/2
1/2
2/2
1/2
1/2
1/2
1/2
1/2
1/2
2/2
2/2
1/2
1/2
1/2
1/2
1/2
1/2
1/2
1/2
1/2
Maximum
cone.
0.017
1.6
0.016
0.092
0.27
0.36
4.2
0.026
0.39
2.*
0.023
0.01»
0.6^
0.033
0.12
0.012
0.17
0.01*
0.019
1.0
0.031
0.013
0.016
0.012
0.012
0.012
0.017
0.017
O.OIl
0.013
m«/l
Median
conc.b
0.016.
0.0014
<0.001
0.029
0.074
o.«s
1.6
0.00053
0.12
1.3
Mean
cone.*
0.014
0.26
O.OC27
0.043
0.099
0.34
2.0
0.0048
0.13
•
-
-
1.3
0.042
0.007
0.33
0.016
0.06
0.006
O.OS3
0.007
0.0095
0.54
0.022
0.0073
0.008
0.006
0.006
0.006
O.OOS5
0.0033
0.0055
0.0065
ke/da*
avg/facility
0.00023
0.0052
0.000054
0.00036
0.002
0.011
0.04
O.OOG096
0.003
0.03
O.OOOS4
0.00014
0.0066
0.00032
0.0012
0.00012
0.0017
0.00014
0.00019
0.011
O.C0044
0.90015
0.00016
0.00012
0.00012
0.00012
0.00017
0.00017
O.OC011
0.00013
Ratio indicates die number of samples in which the specific pollutant was found as compared to the
total number of samples analyzed.
Blanks indicate values below analytical detection limits. Appendix A lists r<
limits for each organic priority pollutant.
iresentative detection
62
-------
TABLE 5-23 TOXIC POLLUTANT CONCENTRATIONS AND LOADINGS IN ROLLOVER TYPE
CAR WASH RAW WASTEWATERS
OJ
Pollutant
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
Chloroform
4-nitrophenol
Bis(2-ethylhexyl) phthalate
Di-n-octyl phthalate
Methylene chloride
Number3
2/2
1/6
0/6
5/6
5/6
4/4
6/6
1/6
6/6
0/2
0/2
0/2
6/6
1/2
1/2
1/2
1/2
1/2
Maximum
cone.
0.0025
0.0005
0.040
0.11
0.230
1.1
0.0006
0.20
1.0
0.037
0.015
0.031
0.016
0.47
mR/1
Median
cone.''
0.0022
<0.0005
0.008
0.013
0.09
0.47
<0.0001
0.11
0.42
Mean
cone.'*
0.0022
0.00008
-
0.013
0.027
0.11
0.50
0.0001
0.11
0.42
0.018
0.0075
0.016
0.008
0.24
kg/day
avg/facility
0.000025
0.00000091
0.00015
0.00031
0.0013
0.0057
0.0000011
0.0013
0.0048
0.0002
0.000086
0.00018
0.000091
0.0027
Ratio indicates the number of samples in which the specific pollutant was found as compared to the
total number of samples analyzed.
Blanks indicate values below analytical detection limits. Appendix A lists representative detection
limits for each organic priority pollutant.
-------
TABLE 5-24. TOXIC POLLUTANT COMENT RAT IONS AND LOADINGS IN TUNNEL
TYPE CAR WASH RAW WASTEWATERS
Pollutant
Antimony
Arsenic
Beryl 1 7 urn
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thai 1 i urn
Zinc
Numbe r
I/I
4/17
0/17
17/17
17/17
8/8
17/17
6/17
17/17
0/1
0/1
0/1
17/17
Max i mum
Cone b
0.0045
0.016
—
0.066
1.7
0.3
2.2
0.0005
0.69
—
--
—
1.5
mg/1
Median.
Cone
~
<0.01
—
0.014
0.026
0.10
0.55
<0.0001
0.13
—
—
—
0.55
Mean
Cone
—
0.0018
—
0.022
0.14
0.15
0.78
0.00011
0.19
—
—
--
0.70
kg/day
Avg/
Facility
—
0.00014
—
0.0017
0.011
0.011
0.059
0.0000083
0.014
—
—
—
0.053
Bis(2-ethylhexyl)
phthalate 1/1
Methylene
chloride
4-nitrophenol
1/1
1/1
0.027
0.011
0.011
a Ratio indicates the number of samples in which the specific pollutant was
found as compared to the total number of samples analyzed.
b Blanks indicate values below analytical detection limits. Appendix A
representative detection limits for each organic toxic pollutant.
64
-------
TABLE 5-25 NUMBER OF DIRECT DISCHARGERS IN THE LAUNDRY INDUSTRY
Subcategory
Industrial
Laundries
Linen supply
Power laundries
Diaper services
Total
Number
1,000
1,300
3,100
300
Direct
Number
0
1
16
0
Dischargers
Percent
0
0.1
0.5
0
Carpet and upholstery
cleaners 2,700 2 0.1
Coin-operated
laundries 32,000 1^0 0.»
Dry cleaning
plants 28,400 6 <0.1
Car washes 22,000 100 0.5
65
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SECTION 6
EXCLUSION OF SUBCATEGOR1ES FROM REGULATION
This section presents the bases for excluding from regulation all subcategories
in the Auto and other Laundries point source category.
6.1 POWER LAUNDRIES, FAMILY AND COMMERCIAL
Summary of Determinations - It has been determined that no further effort
will be given to developing regulations for this subcategory. The bases for this
determination are Paragraph S(a)(iv) of the Consent Decree, which states "the
amount and toxicity of each pollutant in the discharge does not justify developing
national regulations" and Paragraph 8(b)(ii) which states "the toxicity and the
amount of incompatible pollutants (taken together) introduced by such point sources
into treatment works that are publicly owned is so insignificant as not to justify
developing a pretreatment regulation."
Production Process and Effluents - Power laundries are establishments
primarily engaged in operating mechanical laundries with steam or other power.
The average wastewater discharge for this subcategory is 230 nrWday per facility.
The average total toxic metals is less than 0.23 kg/day per facility, which consists
primarily of zinc, 0.099 kg/day per facility, copper, 0.037 kg/day per facility, and
antimony, 0.037 kg/day per facility. Of the toxic organics, phenol is the major
constituent with the average facility discharging 0.071 kg/day.
Plants - There are some 3,100 power laundry facilities in the country.
Status of Regulations - There are no existing regulations for this subcategory.
6.2 DIAPER SERVICES
Summary of Determinations - It has been determined that no further effort
will be given to developing regulations for this subcategory. The bases for this
determination are Paragraph 8(a)(iv) of the Consent Decree, which states "the
amount and toxicity of each pollutant in the discharge does not justify developing
national regulations" and Paragraph S(b)(ii) which states "the toxicity and the
amount of incompatible pollutants (taken together) introduced by such point sources
into treatment works that are publicly owned is so insignificant as not to justify
developing a pretreatment regulation."
Production Process and Effluents - Diaper services are establishments
primarily engaged in supplying diapers (including disposables) and other baby linens
to homes. The average wastewater discharge rate for this subcategory is 160
m3/day per facility. The average total toxic metals for this subcategory is 0.95
kg/day per facility, which consists primarily of zinc, 0.91 kg/day per facility. Toxic
organics were found in only very small quantities.
Plants - There are some 300 diaper service establishments in the country.
Status of Regulations - There are no existing regulations for this subcategory.
66
-------
6.3 COIN-OPERATED LAUNDRIES AND DRY-CLEANING
Summary of Determinations - It has been determined that no further effort
will be given to developing regulations for this subcategory. The bases for this
determination are Paragraph 8(a)(iv) of the Consent Decree, which states "the
amount and toxicity of each pollutant in the discharge does not justify developing
national regulations" and Paragraph 8(b)(ii) which states "the toxicity and the
amount of incompatible pollutants (taken together) introduced by such point sources
into treatment works that are publicly owned is so insignificant as not to justify
developing a pretreatment regulation."
Production Process and Effluents - The coin-op category is made up of
establishments primarily engaged in providing coin-operated laundry and/or dry-
cleaning equipment on their own premises. Wastewater flows from coin-op
establishments average 1* m3/day. Total average toxic metal discharge is 0.01
kg/day per facility, most of which is zinc, 0.00*3 kg/day per facility. Toxic organics
are present only in very small quantities.
Plants - There are approximately 32,000 coin-op facilities in the country.
Status of Regulations - There are no existing regulations for this subcategory.
6.4 DRY-CLEANING PLANTS, EXCEPT RUG CLEANING
Summary of Determinations - It has been determined that no further effort
will be given to developing regulations for this subcategory. The bases for this
determination are Paragraph 8{a)(iv) of the Consent Decree, which states "the
amount and toxicity of each pollutant in the discharge does not justify developing
national regulations" and Paragraph 8(b)(n) which states "the toxicity and the
amount of incompatible pollutants (taken together) introduced by such point sources
into treatment works that are publicly owned is so insignificant as not to justify
developing a pretreatment regulation."
Production Process and Effluents - The dry-cleaning subcategory consists of
establishments engaged in dry cleaning or dyeing apparel and household fabrics,
other than rugs, for the general public. Wastewater discharge from the dry-cleaning
industry is very small. Average total toxic metals is less than 0.01 kg/day per
facility and total toxic organics is less than 0.59 kg/day per facility.
Plants - There are some 28,400 dry-cleaning plants in the country.
Status of Regulations - There are no existirig regulations for this subcategory.
6.5 CARPET AND UPHOLSTERY CLEANING
Summary of Determinations - It has been determined that no further effort
will be given to developing regulations for this subcategory. The bases for this
determination are Paragraph 8(aXiv) of the Consent Decree, which states "the
amount and toxicity of each pollutant in the discharge does not justify developing
national regulations" and Paragraph 8(b)(ii) which states "the toxicity and the
amount of incompatible pollutants (taken together) introduced by such point sources
into treatment works that are publicly owned is so insignificant as not to justify
developing a pretreatment regulation."
67
-------
Production Process and Effluents - Carpet and upholstery cleaners are
establishments primarily engaged in cleaning carpets and upholstered furniture at a
plant or on a customer's premises. Wastewater flows from this subcategory are
extremely small. Average total toxic metals is less than 0.073 kg/day per facility,
with the primary constituents being zinc and copper.
Plants - There are some 2,700 carpet cleaning establishments in the country.
Status of Regulations - There are no existing regulations for this subcategory,
6.6 CAR WASH ESTABLISHMENTS
Summary of Determinations - It has been determined that no further effort
will be given to developing regulations for this subcategory. The bases for this
determination are Paragraph 8(a)(iv> of the Consent Decree, which states "the
amount and toxicity of each pollutant in the discharge does not justify developing
national regulations" and Paragraph 8(b)(ii) which states "the toxicity and the
amount of incompatible pollutants (taken together) introduced by such point sources
into treatment works that are publicly owned is so insignificant as not to justify
developing a pretreatment regulation."
Production Process and Effluents - The car wash subcategory is comprised of
facilities designed for the automatic or self-service washing of vehicles including
cars, vans, and pick-up trucks. There are three types of car washes, tunnel,
rollover, and wand which were described in Section 3.2.5. Average wastewater
flows for tunnels, rollovers, and wands are 75.7, 11.4, and 19.9 m^/day, respectively.
Average toxic metals is less than 0.17 kg/day per facility for tunnels, less than 0.12
kg/day per facility for wands, and less than 0.15 kg/day per facility for rollovers. In
all cases, zinc and lead were the major constituents of the total toxic metals. Toxic
or games were found in very small quantities.
Plants - There are some 22,000 car wash establishments of which an estimated
15,000 are tunnel, 3,500 are wand, and 3,500 are rollover.
Status of Regulations - There are no existing regulations for this subcategory.
6.7 INDUSTRIAL LAUNDRIES
Summary of Determinations - It has been determined that no further effort
will be given to developing regulations for this subcategory. The basis for this
determination is • Paragraph 8(a)(i) of the Consent Decree which states that a
subcategory can be excluded from regulation if 95 percent or more of all point
sources in the subcategory introduce into POTW only pollutants which are
susceptible to treatment and do not interfere with, pass through, and are not
otherwise incompatible with the POTW. All industrial laundries discharge to a
POTW.
Production Process and Effluents • Industrial laundries clean garments and
other materials from a variety of industrial activities. Consequently, toxic
pollutant loads generated in this subcategory are the highest in the industry. The
major toxic pollutants are the toxic metals chromium (trivalent), copper, lead, and
zinc. The total amount of these toxic metal pollutants averages 2.7 kg/day/facility.
If EPA were to promulgate effluent limitations for this subcategory, the limitations
68
-------
would be based on dissolved air flotation technology, which reduces the toxic metal
pollutants by 61 percent. This is a less efficient removal than is currently provided
for these pollutants by the POTW. Accordingly, the pollutants are susceptible to
treatment and do not pass through the POTW. The toxic organic pollutants found
during screening and verification sampling for this subcategory were common
industrial solvents, all of which (with two exceptions) were detected at average
concentrations of less than one part per million. The two exceptions were
ethyibenzene and naphthalene which were detected at a high level at only one plant
each and were uniquely related only to those two sources.
Plants - There are approximately 1,000 industrial laundry facilities in the
country.
Status of Regulations - There are no existing regulations for this subcategory.
6.8 LINEN SUPPLY
Summary of Determinations - It has been determined that no further effort
will be given to developing regulations for this subcategory. The basis for ::his
determination is Paragraph 8(a)(i) of the Consent Decree which states that a
subcategory can be excluded from regulation if 95 percent or more of all point
sources in the subcategory introduce into POTW only pollutants which are
susceptible to treatment and do not interfere with, pass through, and are not
otherwise incompatible with the POTW. All but one linen supply discharge to a
POTW.
Production Process and Effluents - Linen supplies are defined as
establishments primarily engaged in supplying laundered items such as linens,
towels, napkins and uniforms. The major toxic pollutants found at linen laundries
are the same as those found at industrial laundries but at lower concentrations.
(The total amount of toxic metal pollutants averages less than 0.8 kg/day /facility).
The source of these pollutants is the same as the industrial laundry, that is, the
small amount of industrial laundry work done at linen laundries. Since the amount
of industrial laundry done is small at linen laundries, the concentrations and amounts
of pollutants are only about 40 percent of the concentrations and amounts found at
industrial laundries.
Plants - There are approximately 1,300 linen supply facilities in the country.
Status of Regulations - There are no existing regulations for this subcategory.
69
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SECT "ON 7
CONTROL AND TREATMENT TECHNOLOGY
Technology applicable to the control and treatment of laundry wastewaters is
described in this section. Description and evaluation of all technology are based on
treatment system applicability in removing various pollutants prior to discharge to
POTW's or before direct discharge to navigable waterways. Those pollutants found
most consistently and/or at the highest concentration, as presented in Section 5, are
used as a basis for evaluation of current and potentially applicable technology. The
following subjects are discussed in this section:
o Pretreatment technology
o Treatment for direct discharge
o Recycle/reuse technology
o Sludge handling and disposal
Pretreatment of laundry wastewater for discharge to a POTW is dassifed into
three types: (1) conventional, in-piant controls, (2) physical-chemical treatment
systems presently applied, and (3) potentially applicable treatment technology.
Conventional controls are designed to remove gross pollutants such as lint and sand
which obstruct piping and sewer drains, disrupting laundry operations and increasing
plant maintenance costs. In addition, heat reclaimers may be used to reduce the
temperature of the effluent through preheating of incoming fresh water. Physical-
chemical treatment systems (PCS's) are designed to meet regulations established for
the control of pollutants which may include oil and grease and heavy metals, and
high pH as defined by sewer ordinances for various municipal districts. Some
physical-chemical systems are designed for the expressed purpose of reclaiming
laundry wastewater for use in the wash process.
Controls required for direct discharge of laundry wastewaters are specified, in
this section, as a combination of physical-chemical treatment and on-site biological
treatment. Further removal of the pollutants mentioned above is required in
addition to reducing levels of BOD and TSS before direct discharge. Assessment of
the capabilities of small-scale biological systems for treatment of laundry
wastewater is based on limited data from coin-operated laundries.
Recycling or reusing laundry wastewater can achieve a reduction in the
volume of effluent per unit mass of laundry washed. In cases where recycle or reuse
is practiced, effluents from various systems treating laundry wastewater are mixed
with incoming fresh water and then recycled through the wash process. An example
of one reuse practice is utilization of untreated rinse water from one washload as
initial washwater for a second washload. The technical feasibility of recycling
laundry wastewater is discussed in Section 7.3.
Sludges resulting from the treatment of laundry wastewater must be handled
and disposed of. Dewatering equipment, for the purpose of reducing sludge volume,
is described in Section 7.4. Ultimate disposal of laundry sludge is accomplished by
landfilling or incineration.
70
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7.1 PRETREATMENT TECHNOLOGY
Since greater than 99% of all laundries discharge to POTW's removal of
incompatible pollutants is of major concern when describing wastewater controls for
the laundry industry. The extent and type of control practiced by individual
laundries has been dependent on local sewer ordinances, geographic location, POTW
limitations, and economic considerations. In Table 7-1, the number of plants in each
laundry subcategory having various control technologies is estimated from the
technical survey.
7.1.1 Conventional Technology
Generally, conventional technology is designed to remove gross pollutants such
as lint, sand, grit, and free oil. Heat reclaimers are used to recover heat from the
wastewater prior to discharge in order to preheat incoming fresh water.
Conventional equipment for the control of solids, free oil, and temperature is
described in the following subsections.
7.1.1.1 Solids Removal
Bar screens, lint screens, and catch basins (settling pits) are devices used to
remove sand, grit, lint, and other noncolioidal solids from laundry wastewater.
Solids removal is typically accomplished in many laundries to prevent the
obstruction of piping and drains, thus ensuring constant hydraulic capacity.
Bar screens are constructed of flat steel bars welded together in a grid
pattern. Rectangular spaces formed by the steel grid are 6.3 mm (0.25 in.) by 19
mm (0.75 in.) in area and are designed to allow the free flow of effluent v/hile
removing large objects composed of paper, wood, etc., from the wastewater stream.
In the laundry industry, bar screens are usually cleaned by hand.
Lint screens are usually installed after bar screens and will remove lint and
other particles such as sand and grit. Lint screens at laundries are generally of
cylindrical or rectangular design, are constructed of wire mesh or perforated metal
plate, and have openings 9.5 mm (0.37 in.) to 3.2 mm (0.12 in.) in width. They are
manually or mechanically cleaned. Hand cleaning of a lint screen is accomplished
by directing a stream of water from a hose against the screen in a direction opposite
to the wastewater flow. Mechanical removal of accumulated debris is mainly
accomplished by rotating or vibrating the lint screen to allow the trapped lint to fall
off and be collected. Automatic water jets may also be used to aid in the removal
of trapped lint from screens.
Catch basins are also used in combination with lint screens to remove sand and
grit from laundry wastewater. Catch basins are typically built below ground and
have a hydraulic detention time of between 15 and 40 minutes. Basins rely on the
difference in the specific gravities of solids versus water to achieve particle
settling. The effectiveness of solids settling will depend upon the characteristics of
the particular laundry wastewater and the hydraulic detention time of the catch
basin. The percent of total solids removed will generally increase, to a maximum,
with increasing detention time.
71
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TABLE 7-1. ESTIMATED PERCENT OF LAUNDRIES (BASED-ON
TECHNICAL SURVEY DATA) HAVING CONTROL
TECHNOLOGY
Control technology
Pretr'eatment technology
(Number of responses)
Bar screens
Lint screens
Catch basins
Heat reclaimers
Oil skimmers
Equalization tanks
pH adjustment
Physical-chemical systems0
Otherd
Industrial
laundries
(7«0
2.7
70
72
70
15
1.2*
K3*
8.1
Linen supply
laundries
(59)
.1
81
78
81
0
2.1°
.1
0.3b
3.»
Estimate based on 13 physical-chemical systems operating at the 1,013 industrial
laundry indirect discharges. Also, 12 of these systems have equalization tanks.
Estimate based on 5 physical-chemical systems with equalization operating at
the 1,308 linen supply indirect discharges, plus the 1.7% of linen supplies that
have equalization tanks based on survey responses.
Major unit operations consist of chemical addition and floe removal by dissolved
air flotation.
Other includes filtration, separators, oil hold back devices, and miscellaneous
operations.
72
-------
Holding tanks with detention times of 2 to 4 hours are considered adequate for
providing flow equalization of laundry effluent. Detention times of this magnitude
will usually provide the maximum removal of suspended solids achievable without
resorting to additional technology such as physical-chemical treatment. Physical,
chemical, and biological reactions can also occur in an equalization tank, which may
cause reductions in pollutant concentrations (46). Details on the functions of How
equalization are given as part of the general description of dissolved air flotation
treatment.
7.1.1.2 Free Oil Removal
Oils and greases in laundry wastewater are compounds that can be separated
from water by freon, hexane, and/or ether extraction. Non-emulsified or free oil
may comprise a portion of the total oil and grease in a particular laundry
wastewater. Data collected from industrial laundries indicate that 5% to 10% of
the total oil and grease loading may be free oil.
Free oil removal technology relies on differences in specific gravities of oils
and grease versus water (24). Treatment techniques involve retention of the oily
water in a holding tank allowing gravity separation of the oily material from water
to occur. The floating oils are then skimmed from the water surface.
7.1.1.3 Temperature Control
Heat reclaimers are used in the laundry industry to preheat incoming fresh
water prior to its use in the wash process. Preheating is accomplished with
reclaimers by noncontact heat transfer from laundry wastewater. As a result,
laundry effluent temperatures are reduced from 60°C-70°C (140°F-I60°F) to 27°C-
38°C (SO°F-iOO°F). Preheating of washwater with heat reclaimers reduces the
amount of fuel needed to heat fresh water.
7.1.1.4 Capabilities of Conventional Technology
Data are provided in Table 7-2 for control equipment presently in place at
three laundries. The system, consisting of bar screen, lint screen, catch basin and
heat reclaimer, was selected as typical because it is in place at 70 percent or more
of industrial and linen supply laundries as presented in Table 7-1 survey data.
The data in Table 7-2 indicate that the effectiveness of conventional
treatment in removing pollutants is variable and the results are basically
inconclusive. Median removal rates ranged from zero to 32 percent for conventional
and toxic pollutants. For the purpose of evaluating other treatment technologies,
conventional treatment is assumed to be in place providing for the removal of gross
pollutants only.
7.1.2 Incompatible Pollutant Removal — Presently Applied Technology
Laundries operating under regulations that limit the discharge of incompatible
pollutants are currently using dissolved air flotation systems (DAF5) for wastewater
treatment. This system is described in the following section.
73
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TABLE 7-2. RESULTS OF CONVENTIONAL TREATMENT SYSTEM la»b
Pollutant
parameter
Oil and grease
BOD5
TSS
Copper
Lead
Zinc
Number
of data
_ points
9
9
9
8
9
5
Washroom
discharge,
median
concen-
tration,
mR/L
620
310
500
0.12
0.52
0.45
Range,
190 -
170 -
210 -
0.03 -
0.22 -
0.38 -
mg/L
1,350
660
1,300
0.69
2.4
0.86
Sewer
discharge,
median
concen-
tration,
mR/L
480
300
480
0.10
0.27
0.42
Ranpe,
140 -
190 -
270 -
0.01 -
0.05 -
0.005 -
mK/L
1,360
970
1,600
0.42
1.3
0.83
Median, %
removal
19
6
0
28
32
0
Range, %
0 -
0 -
0 -
0 -
0 -
0 -
65
IS
20
66
91
99
aOata based on sampling results from three laundries.
''System uses a bar screen, lint screen, catch basin and heat reclaimer.
-------
7.1.2.1 General Treatment Strategy
DAF treatment of laundry wastewater is comprised of the following unit
operations: flow equalization, chemical addition, floe removal, and sludge disposal.
Figure 7-1 is a block diagram for laundry wastewater pretreatment using DAF
technology. Conventional controls, such as iint screens and catch basins are
considered to be already installed in laundries and will not be discussed further.
Equalization tanks were briefly described under conventional equipment, however
their use in the laundry industry has been mainly restricted to providing constant
flow to DAF systems.
Flow Equalization - Equalized flow is defined as the constant flow of laundry
wastewater through the treatment system. Flow is constant if it is maintained at
approximately the same level during the entire period of operation of the DAF
system. For laundries this period of time is usually 8 to 10 hours. A secondary
objective of equalization is to dampen the mass flow variation of wastewater
contaminants by blending (25). Reductions in the variation of flow and pollutant
concentrations will minimize the required capabilities of a particular treatment
system. Because laundry wastewater flows and pollutant concentrations can vary by
orders of magnitude during a day's operation, flow equalization prior to DAF
treatment is a recommended technique.
Equalization tanks currently in use at laundries are of steel or concrete
construction and are built above or below ground. Hydraulic detention tim« for
laundry wastewater equalization is usually 2 to * hours, dependent on washroom
operation, building space limitations, and design criteria of the DAF system.
Equalization tanks at laundries require cleaning on a regular basis to remove settled
solids and grease deposits. The approximate areas required for equalization tanks
are given in Table 7-3 for 2-hr and 4-hr detention times of various wastewater
flowrates.
Chemical Addition - Pollutants, such as oil and heavy metals in laundry
wastewater, are usually in the form of colloidal suspensions which cannot be
effectively treated solely by physical techniques. Chemical addition is thus used to
aggregate the colloidal material into particles that can be physically removed by
flotation, sedimentation, or filtration.
Emulsified oil and grease is aggregated by chemical addition through the
processes of coagulation and/or acidification in conjunction with flocculation
mechanisms. Coagulation involves the use of chemical additives that destabilize the
colloidal material either by reducing the electrostatic repulsive forces between
colloids or by forming positively charged hydrous oxides which are absorbed on the
surface of the colloid (2b, 27). Other pollutants such as lead, copper, and zinc,
which exist as colloids in laundry wastewater are also destabilized by coagulation.
Acidification of oil and grease colloids is accomplished by lowering the pH to a point
where the emulsion is "broken", thus allowing dispersed oil droplets to aggregate
(2*). Coagulation and acidification may both be used in a DAF system to treat
laundry wastewater.
Flocculation - Flocculation is defined as particle transport and contact
occuring as a result of colloidal destabilization (coagulation). Particle transport
occurs due to thermal motion, bulk fluid motion (accomplished by mechanical
75
-------
CHEMICAL
FEED
SKIMMERS
INFLUENT-
EQUALIZATION
TANK
i
MIX
TANK
SLUDGE
PIT
FLOTATION
m
SLUDGE
WEIR
RECYCLE
EFFLUENT
COMPRESSED
AIR
Figure 7-1. DAP treatment system for laundry wastewater using
recycle flow pressurization.
-------
TABLE 7-3 AREA REQUIREMENTS FOR LAUNDRY
WASTEWATER EQUALIZATION
Selected
flowrate,
m^/day
(gai/day)
570
(150,000)
3SO
(100,000)
2SO
(75,000)
190
(50,000)
38
(10,000)
19
(5,000)
Tank
capacity,
nv
teal)
detention
Tank
area.b
m-3
(ft2)
timea'c
Two-hour
210 100
(56,000) (1,100)
130
(35,500)
110
(2S,000)
71
(18,700)
15
(4,000)
8
(2,000)
63
(680)
50
(530)
33
(360)
7
(75)
4
(40)
Tank
capacity,
nv
(gal)
detention time'
Four-hour
360
(94,000)
240
(62,500)
ISO
(47,000)
120
(31,000)
23
(6,000)
11
(3,000)
170
(1,800)
no
(1,200)
84
(900)
56
(600)
11
(115)
6
(60)
In determining required tank capacity an additional hour detention time
was factored into the calculation. Variations in wastewater flow over a
normal day's operation are assumed to be minimal for this example;
therefore, tank sizes shown should be considered the minimum required
for laundry wastewater flow equalization.
Tank area has been determined assuming a tank water level of 7 ft.
Based on 10-hour day.
77
-------
stirring), and differential settling (26). In all cases floes properly formed from
interpartide contact are then capable of being removed by physical means.
Destabilization of colloidal suspensions in laundry wastewater is accomplished
by adding coagulant chemicals at prescribed rates to the raw wastewater. Coagu-
lants currently in use at laundries are listed below:
Aluminum sulfate (Alum, Al2 ($0^)3)
Calcium chloride (CaCl2)
Ferric sulfate (Fe2(SO4h)
Ferrous sulfate (Fe(SO^))
Cationic polyelectrolytes
Floe particles that form as a result of chemical coagulation contain the
colloidal material intended for removal. Since proper floe formation is dependent
on various particle transport mechanisms (flocculation), the physical design of
chemical addition equipment must provide adequate time and mixing for
interpartide contacts during coagulation.
Design parameters considered important in achieving proper particle contact
indude hydraulic detention time in the mix tank and the physical methods used for
mixing. Generally, the required detention time for flocculation is inversely
proportional to solids concentration (26). Baffles are generally used in mix tanks to
provide adequate partide contact through mixing. Additional mixing is also
provided through turbulence that occurs during stream pressurization due to
pumping and air injection. The main purpose of stream pressurization is for floe
removal by dissolved air flotation. This operation is discussed in the following
section.
Dissolved Air Flotation - In the pretreatment of laundry effluents, floe is
brought to the surface of a thickener unit by means of dissolved air flotation (DAF).
DAF is accomplished by pressurizing all or part of the effluent stream with air at *0
psig to 80 psig. Since the pressure exerted on the wastewafir is greater than
atmospheric, the saturation point of air in water is raised, allowing excess air to
become dissolved. After the additional air is dissolved in the wastewater, the
pressure is reduced back to atmospheric, forcing dissolved air out of solution in the
form of minute bubbles throughout the entire volume of the liquid (23). These
bubbles become attached to floe partides causing them to rise 10 the surface of a
flotation tank (thickener), where the floe solids can be skimmed off by rotating
troughs or moving blades.
The principal components of a DAF unit are a pressurizing pump, retention
tank, pressure-reducing valve, air injector, and a flotation tank. .For laundry
wastewater, two modes of pressurization are currently in use: full flow
pressurization (FFP) and recyde pressurization (RP). In FFP the entire effluent
stream is pressurized. In RP a stream of treated water is drawn from the flotation
tank, ranging in volume from 50% to 120% of the effluent stream; this recyde
stream is pressurized and mixed with the effluent as it enters the flotation tank.
Factors that affect the design of a DAF unit indude feed solids concentration,
hydraulic loading rate, and partide rise velocity (28). Airsolids ratios are
frequently used to determine the design criteria for DAF systems. This ratio is
78
-------
defined as the weight of compressed air utilized during pressurization compared to
the weight'of solids entering the flotation tank (23). Typical airrsolids ratios for
DAF units are in the range of 0.005 to 0.1 (23, 27). Higher air:solids ratios can
cause floe shearing due to increased turbulence, resulting in an overall loss of
system efficiency.
The operating variables, ainsolids ratio, hydraulic loading rate, and solids
loading rate have a direct effect on the performance of a DAF unit. For effective
treatment it will usually be necessary- to conduct tests at the particular laundry
before installation of a full-scale DAF unit since large variations exist in
contaminant loadings and hydraulic loadings between laundries.
Pretreatment technology using DAF is being practiced at a number of
industrial and linen supply laundries. The results of sampling of wastewaters at If
of these operational systems are presented in Appendix C. Table 7-4 summarizes
the removal efficiencies of selected industrial laundry DAF systems in terms of
percent removal and treated effluent quality for conventional and toxic pollutants.
The data in Table 7-4 indicate that DAF treatment is effective Ln reducing
toxic metals. Average lead and zinc removals were greater than 90 percent.
Copper removal averaged 75 percent and chromium removal averaged greater than
57 percent. Detracting from the efficiency of the DAF system, however, are the
variations that exist between different plants and among the various pollutants. For
example, chromium removal ranged from 41.8 percent at Plant D to 99.7 percent at
Plant L, and the concentration of chromium at the same plants was 0.57 mg/1 and
0.005 mg/1, respectively. This variability in the effectiveness of the same
treatment technology is believed to be the result of varying system parameters such
as air flow, chemical addition, and raw waste characteristics.
The data also shows that the DAF system is effective in removing toxic
organic pollutants from laundry wastewater. The removal of total toxic organics
was significant with an average removal of 77 percent and a range of 53.9 percent
to 92.7 percent. Although DAF systems are not designed to remove organics, the
removal of oil and grease accomplishes an incidental removal of toxic organics
soluble in the oil. Quantifying effluent quality in terms of toxic organics is
difficult, however, because of the variations in specific organics found from plant to
plant, the range of solubilities of those organics, and the variations in oil and grease
removal that can occur with the DAF system.
7.1.3 Incompatible Pollutant Removal - Potentially Applicable Technology
Technologies not used on a commercial scale but applicable to laundry
wastewater treatment include gravity settling, multimedia filtration, ultrafiltration,
diatomaceous earth filtration, and eiectrocoagulation. These technologies include
processes which may replace certain unit operations (such as gravity settling
replacing DAF) or which may replace the entire physical-chemical process (such as
ultrafiltration replacing a DAF system).
7.1.3.1 Gravity Settling
Gravity settling or sedimentation may also be used to remove floe panicles
from the laundry wastewater. After chemical addition, wastewater flows into a
-------
TABLE 7-4
SUMMARY OP POLLUTANT REMOVAL EFFICIENCIES AT
SELECTED PLANTS USING DAP TECHNOLOGY
POLLUTANTS
TSS
BOO
COD
OltftGrcMe
Antimony
Cadmium
Chromium
Copper
CD
^) Lead
t II r 1 1 • 1
nKftcel
Zinc
Total Teak Organlci
PLANTS
A
7*. 9
•
JO
79.7
»9.t
>98.2
•3.1
66.7
97.)
21.6
93.8
„.•
•9/1
98
3.200
1*3
«O.OI
<0.001
0.17
0.5
O.I)
0.15
0.1)
1.)
B
93.1
•
6). 8
36.8
b
86.)
»l.9
79.1
97.6
66.7
9J.6
>3.9
•9/1
tB
l.)00
190
<0.01
0.02)
«0.l)
0.3)
0.1)
<0.05
0.2
*.2
C
87.7
•
62.)
77.6
b
>9B.)
•8.3
71.7
98.)
b
97.*
e
•g/l
6*
1,100
170
«0.01
<0.001
0.61
0.3*
0.067
96.7
66.7
10.0
97.7
>93.8
97.0
*
•9/1
18
5*0
1.100
8%
0.029
<0.001
O.I
0.2
0.07
<0.005
0.06
L og/l
73.0 1*0
82.1 250
7*.» 910
93.6 28
89. • 0.018
96.7 <0.002
99.7 cO.OOS
97.3 O.I
99.8 -0.01
93.0 cO.OOS
93.0 0.10
92.7 0.61
Z mg/t
•2.0 510
33.6 770
•
•7.2 360
0 0.09
•
•7.8 O.IJ
•O.I 0.86
6*.6 0.38
33.7 0.10
63.2 0.77
•
t k»»l
79.7
60.6
67.0
72.3
>J0.9
>9).»
»7.l
73.2
93.*
70.0
92.0
77.1
• Not Aratrud
b DtU Point Not Used (Influent <0.0) mg/l)
c Clfhienl Grater than kifhienl. Sujpecled Simpllrg Error.
-------
tank (clarifier) having sufficient detents::n time to allow floe particles to settle.
Moving scrapers located at the bottom oi :he tank collect the settled floe and
discharge it to a sludge collection tank.
At present, pretreatment of laundry wastewater incorporates DAF rather than
gravity settling for floe removal. A system utilizing sedimentation is currently
treating the effluent from one institutional laundry (with a workload comparable to
that "of a power laundry) for direct discharge. It is difficult to compare the
effectiveness of these two techniques, since available data involving laundry
applications are limited. DAF units generally operate at surface loading rates four
to eight times higher than gravity settlers. That is, the detention time required and
thus the capacity or volume of the DAF unit would be significantly less than a
gravity settler. Since laundries often have little space for treatment equipment, a
PCS with DAF is normally chosen due to the significant difference in required tank
volumes.
7.1.3.2 Filtration
Further removal of floe from laundry wastewater may be accomplished by
multimedia filtration. In general, those systems whose main purpose is to recyle
part of the laundry effluent utilize filtration, while systems discharging all treated
effluent to a POTW do not incorporate filtration. Variability in final effluent
quality due to floe carryover or very fine floe particles may be reduced by the use
of a multimedia filter.
Filters are sealed cylindrical tanks containing layers of filter media of
different specific gravities and particle sizes. Media are arranged so that the
heaviest material of the finest grade rests at the bottom of the tank. Wastewater is
pumped under pressure through the top of the filter, coming in contact first with a
coarse medium of low specific gravity. As water flows through the filter it
encounters media of increasingly finer grades and greater densities. Total head loss
across the filter increases as particles become trapped in the media. When head loss
raches a predetermined level, the influent flow is shut off and the filter is
backwashed with air and water in the direction opposite to influent flow (27).
As previously cited, however, a certain amount of variability in the efficiency
of a DAF system exists, and increases in effluent oil and grease will readily clog or
block a filter. For this reason, filtration following DAF is not considered feasible
for general application in this industry.
7.1.3.3 UltrafjJtration
Ultrafiltration is a process in which wastewater is pumped through a
semipermeable polymeric membrane at an operating pressure of SO psig to 100 psig.
Water and most dissolved materials pass through the membrane, while suspended
solids and other colloidal materials such as emulsified oils are retained and
concentrated. The capacity of a UF membrane to pass water is an important design
criterion. The rate of filtration is termed flux, which is the volume of water
permeated per unit membrane area per unit time, usually expressed as gallons per
square foot.
81
-------
Bench-scale and pilot scale tests have been performed to determine the
effectiveness of UF in treating laundry wastewaters (14). Results have indicated
that although pollutant removal rates are on the order of 95 percent for metals and
conventional pollutants, clogging and fouling of the membrane reduced membrane
flux to levels too low for industrial application.
From a technical standpoint UF systems with tubular modules have advantages
over physical-chemical systems utilizing chemical addition and DAF. UF does not
incorporate coagulation; thus it does not require chemical additives. In terms of
space requirements, UF systems would require less space than comparable physical-
chemical systems with DAF. This is due to the number of unit operations involved
in each system; these are chemical addition, DAF, and possible filtration for PCS's,
versus filtration for UF systems.
When considering the cost of treatment, however comparison of the two
technologies is less well defined. Since the cost of UF treatment is largely
dependent on flux, it will be necessary to evaluate UF systems on a full-scale level.
At this time there has been no long-term operation of a UF system at an actual
laundry.
7.1.3.* Diatomaceous Earth Filtration
Diatomaceous earth (DE) filters have been applied to treatment of laundry
wastewater. In DE filtration a thin layer of precoat is formed on a porous septum in
order to strain out suspended solids in the effluent (27). A cake is formed on the
filter by deposition of suspended solids and DE, which is added to the effluent at a
constant rate. Head loss through the cake increases as filtration progresses; reverse
water flow is initiated when a preset maximum head loss is reached. Generally, DE
filtration is capable of excellent removal of suspended solids but not of colloidal
matter (27).
Treatment of wastewater at a linen supply laundry was accomplished by DE
filtration. Effluent from an equalization tank was injected with DE and a
proprietary oil adsorbent, then pumped through precoated pressure filters. The
system provided moderate removal rates, 32 percent BOD, 65 percent TSS, 43
percent oil and grease and 40 percent metals. The system, although once in
f ullscale operation, it has since been replaced by a treatment system using calcium
chloride coagulation and DAF.
7.1.3.5 Electrocoagulation
An eiectrocoagulation (EC) process has been pilot tested on a laundry waste-
water. In EC, an electric current is continuously conducted through a tank
functioning in a plug-flow mode. Current is provided by electrodes immersed in the
wastewater. EC system are designed to treat laundry wastewater through two
mechanisms. With the first, electrolysis induces coagulation by neutralizing or
Imparting a positive charge to negatively charged colloidal material. With the
second, microbubbies formed as a result of electrolysis float the resulting floe to
the surface of the contained effluent where it can be skimmed off (30).
In the pilot tests chemical addition was required prior to electrolysis to
achieve removal of incompatible pollutants. Alum, sulfuric acid, and polymer were
82
-------
added. Removal rates included 80 percent oil and grease, 53 percent BOD and T5S,
and 05 percent metals.
Theoretically, EC processes are capable of performing both coagulation and
floe flotation. In practice, however, chemical addition of the type described for
physical-chemical treatment is necessary to achieve an effluent quality comparable
to that achieved by presently applied technologies.
7.1.3.6 Other Technologies
Other treatment technologies have been laboratory or pilot tested on laundry
wastewaters with varying degrees of success. These technologies include reverse
osmosis, foam separation, distillation, and carbon adsorption (22, 31-33). In general,
these techniques were found either not applicable to removal of pollutants found in
laundry wastewater or are considered not economically comparable to technologies
previously described.
The use of carbon adsorption and steam stripping technologies following DAF
treatment was investigated specifically for the further removal of toxic organics.
Steam stripping was not considered technologically viable because of the boiling
point characteristics of many of the toxic organics found in laundry wastes.
Although volatile and semivolatile organics would be substantially removed by
stripping, organics with high boiling points, i.e., phthalates would not be reduced.
Carbon adsorption following DAF was also not considered technologically feasible
due to the characteristics of DAF effluent. Oil and grease levels found in typical
DAF effluents are sufficiently high that a filtration step would be required prior to
carbon adsorption to prevent fouling of the carbon.
7.1.4 Space Availability
Since laundries may have limited additional space for treatment equipment, it
is important to note the space required for PCS's. Average space requirements for
physical-chemical treatment by DAF are presented in Table 7-5 for selected
effluent flowrates. Chemical addition and floe removal equipment are the essential
hardware required; equalization tanks are assumed below grade.
A site survey of 45 industrial laundry sites concluded that space is generally
available for the installation of treatment equipment (See Appendix B). Less than
10 percent of facilities would have major problems installing equipment. The costs
associated with space allocation were estimated from the survey. These costs were
included in site preparation charges as a part of capital costs presented in Section 8.
7.2 TREATMENT FOR DIRECT DISCHARGE
As indicated in Section 5, an extremely limited number of laundries are direct
dischargers. Only one linen supply laundry is known to be a direct discharger. No
industrial laundries are known to be direct dischargers. A survey of the industry
identified 23 coin-operated laundries and one institutional laundry (with a workload
similar to that of a power laundry) that operate waste water treatment systems.
Thus, technical data on the performance of laundry wastewater treatment systems
(other than the pretreatment systems discussed in the preceding subsection) are
83
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TABLE 7-5 AREA REQUIREMENTS FOR PCS's
Required area
Exemplary flbwrate, for system,
m3/day (gal/day) m^ (ft?)
570 (150,000) <»5 (500)
380 (100,000) 27 (300)
280 (75,000) 23 (250)
190 (50,000) 18 (200)
38 (10,000) 8 (85)
19 (5,000) 5 (55)
aBased on a maximum height of 3.05 m (10 ft).
b
Based on a 10-hr, day.
84
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quite limited. Hypothetical treatment systems for the direct discharge of linen
supply and 'industrial laundry effluents are described in the following subsections,
7.2.1 Primary Treatment
Pollutants typically found in laundry wastewater are identified in Section 5 of
this, report. Based on information provided there, pollutants which may require
control before direct discharge include oil and grease, pH, BOD, TSS, lead, copper,
chromium, and zinc. Treatment technologies capable of controlling these
parameters are classified as either physical-chemical or biological.
A previous study has concluded that biological systems cannot effectively
treat industrial strength laundry wastewater (17). One possible explanation for this
ineffectiveness is the inability of biological systems to cope with high concen-
trations of oil and grease, which may be found in linen supply and industrial laundry
effluents (see Section 5). Studies have indicated that systems incorporating
trickling filters or activiated sludge can effectively treat effluents with emulsified
oil concentrations of 100 mg/1 or less (3*, 35). Median oil and grease concentrations
found in linen supply and industrial laundry wastewaters were 300 mg/1 and 720
mg/1, respectively. Microbial metabolism, a primary mechanism for pollutant
removal by biological systems, may be inhibited by oily materials due to the low
solubility of oil, the chemical configuration of oil molecules, and the nature of
microbial surface (36).
Since biological systems are limited in their capability, two stages, primary
and secondary treatment systems may be considered necessary for linen supply and
industrial laundry effluents being directly discharged. Noting the removals of
pollutants for pretreatment DAF is considered an effective primary treatment
technology and is used as the basis far primary treatment prior to direct discharge.
7.2.2 Secondary Treatment
Considering the pollutant concentrations shown in Appendix C for wasteuater
after physical-chemical treatment, secondary treatment may be required before
linen supply and industrial laundry effluents can be discharged to surface waters.
Biological techniques are considered suitable for secondary treatment of these
effluents. This assumption is based on limited performance data from coin-operated
laundries currently operating small-scale biological units.
7.2.2.1 Biological Treatment
Two biological units, trickling filters and facultative lagoons, are consicered
for potential secondary treatment of laundry effluents. Selection of this particular
equipment is mainly based on survey information from coin-op laundries. A general
characterization of industrial and/or linen supply laundry wastewater after primary
treatment is given in Table 7-6. The indicated BOD loading of 300 mg/1 was used
for developing design parameters for biological systems incorporating either
facultative lagoons or trickling filters.
Wastewater from primary treatment is considered similar to raw wastewater
from coin-op laundries (see Table 5-8). Since certain parameters such as BOD are
85
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TABLE 7-6 CHARACTERIZATION OF LAUNDRY
WASTEWATER AFTER PHYSICAL-CHEMICAL TREATMENT
Estimated
concentrations
after P-C
treatment,
Pollutant mg/L
Oil and grease
BODs
T5S
Phosphorus
Copper
Lead
Zinc
PH
70
300
100
0.*
0.2
0.1
0.4
7.0
TABLE 7-7 EFFLUENT CONCENTRATIONS FOR LAGOONS TREATING
WASTEWATER FROM COIN-OP LAUNDRIES3
Pollutant
Parameter
BOD5
TSS
pH
Phosphorus
Oil and grease
Number of
data points
10
10
5
1
1
Median
effluent
concentration,
mg/1
20
S3
9.3
0.02
2.5
Range
mg/1
1 - 130
1* - 273
8 - 9.9
--
—-
aData are from three coin-op laundries; average effluent flow rates
were reported as 3 m^/day (770 gpd), 5.7 m3/day (1,500 gpd), and 25
m*/day (6,500 gpd).
86
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somewhat higher for primary treated was*ewater, the biological system for linen
supply and industrial laundries must be designed accordingly.
Stabilization Pond - An aerobic/anaerobic (facultative) stabilization pond
(lagoon) has been considered for secondary treatment of laundry waste water. In this
system, surface aerators are used to mix the effluent in the upper portion of the
lagoon. Oxygen supplied to this area from aerator action is used by aerobic
microorganisms for metabolic waste conversion and BOD reduction. Incoming solids
and solids (microorganism cell tissue) formed during conversion settle to the lower
regipn of the lagoon where anerobic decomposition occurs, resulting in further BOD
reduction. Final effluent from this type of lagoon is generally more highly
stabilized than effluent from completely aerobic systems (23).
Table 7-7 presents effluent concentration data for three lagoons operated by
coin-op laundries. These data were taken from NPDES monitoring reports, and no
influent concentration data were available. Thus, the data serve only as relative
indicators of achievable effluent quality (in terms of BOD^, suspended solids,
phosphorus, and oil and grease).
Tricking Filters - Trickling filters are also considered viable secondary
treatment. A trickling filter consists of a circular basin filled with permeable
media to which microorganisms are attached and through which the laundry effluent
is percolated (23). The filter medium may consist of plastic chips or rocks; the
effluent is distributed over the top of the media by means of a rotary distributor
(23).
Microorganisms attached to the filter medium degrade the organic material
present in the wastewater, resulting in an initial reduction in effluent BOD. Solids
formed during filter action are earned with the percolating effluent through the
underdrain to a settling tank. Settling of solids in the tank is an additional
mechanism for BOD reduction.
Survey data showing the reduction of various pollutants by trickling filter
systems are given in Table 7-8 for two coin-op laundries. Average flowrate for one
laundry is 15 m^/day (4,000 gpd); flowrate for the other laundry is not available
from survey data.
7.2.2.2 Other Technologies
Secondary treatment of laundry wastewater by carbon- adsorption has been
tested on a pilot scale. Effluent from the UF unit described in Section 7.1.3 was
continuously directed through a carbon column during testing procedures. Removal
of dissolved organics by activated carbon occurs through adsorption, a process where
physical and chemical attractive forces bind organic molecules to a highly porous
carbon surface. Generally, low molecular weight or highly soluble organics are less
readily removed from wastewater by carbon than organics of low solubility and/or
high molecular weight.
Limited performance data developed during a two-week pilot-scale test of
activated carbon treating laundry wastewater from a UF unit (14) showed that
carbon did not further reduce BOD concentrations. Thus, activated carbon is not
considered as applicable for secondary treatment.
87
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TABLE 7-8 PERFORMANCE FOR TRICKLING FILTERS TREATING
WASTEWATER FROM COIN-OP LAUNDRIES*
Raw Waslewater
Pollutant
Parameter
BOD
T5S
PM
Number
of data
17
17
II
concentration
median
•HR/I
163
91
8.3
Range,
IT1R/I
12 - £00
30 - »,3W
8.1 - 9.3
Median effluent
concentration,
rne/l
32
7.7
Range, Median, %
ing/l removal
1.3 - IjkZ 79
0.9 - 282 M
7.» - 8.3 --•»
RanRe
0 -
0 -
I *
99
99
-_b
•Data from two coin-op laimdrlesi average effluent tlowrate reported as I} m'/day (4,000 gpdlj Itowrate lor other laundry unknown.
*>Nol applicable.
00
03
-------
7.3 RECYCLE/REUSE TECHNOLOGY
Due to the rising costs of fuel and water incurred by laundry facilities, a few
operators are presently reusing or recycling their wastewater. For purposes of
discussion, reuse is defined as the use of untreated wastewater in a second
application that is different from the orginal. Recycle is defined as the treatment
of laundry wastewater by physical-chemical means enabling it to be used again in
the washing process. Both reuse and recycle techniques are discussed in the
following sections.
Reuse - In reuse strategies, laundry wastewater from one or more rinse cycles
is introduced into the wash process in the initial flush, break, and/or suds cycles.
Holding tanks are used for storage of rinse waters until a subsequent laod of laundry
is ready for washing. Fresh water is added to the rinse water in amounts that
provide an adequate quality of water for use in a preliminary wash stage. A laundry
operator will typically arrange his loads so that wastewaters from lightly soiled
articles can be reused on more heavily soiled loads. Before reuse, wastewaters may
be treated by conventional techniques such as lint screens or catch basins.
Recycle - In order to recycle an equalized flow of laundry wastewater,
physical-chemical treatment techniques are employed to achieve a water quality
acceptable for use as a washing medium. Quality specifications are difficult to
define since laundry personnel are not in agreement as to what constitutes
acceptable water quality or the means of achieving such quality. Laundry
wastewater recycling is a comparatively new concept; only a very small number of
laundries (approximately 7) are practicing effluent recycle. Thus it is difficult to
determine the technical feasibility of effluent recycle on a large scale.
Two physical-chemical treatment systems are currently being used for laundry
wastewater recycle. These systems use alum or polyelectrolyte for chemical
coagulation, followed by dissolved air flotation and filtration for floe removal.
Treated effluent is usually stored in an insulated holding tank and pumped to
the washing machines as required. Recycled water is mixed with fresh water before
being used in the wash process. In present applications, 60% to 80% of this mixture
is recycled to keep dissolved solids concentrations at an acceptable level as part of
achieving the overall water quality necessary for laundering. Laundries with these
recycle systems report that the treated water is acceptable for recycle purposes so
long as the necessary dilution is provided.
Recycle of industrial-strength laundry effluent is being practiced at only one
or two facilities with prototype treatment units. Therefore, the technical
feasibility of laundry effluent recycle on an industry-wide basis has not been proven.
Potential technical problems involving recycle which may require further
consideration are listed below:
o Specific contaminants such as dyes and solvents may render the treated
effluent unacceptable for recycle.
o Increased concentrations of dissolved solids in recycle water may render
it unsuitable for certain laundering applications unless high dilution
89
-------
ratios are used. Higher dilution ratios reduce the economic
attractiveness of recycling.
o Influent streams to recycle systems generally contain higher pollutant
loadings than influents to once-through treatment systems employing
similar treatment technology. This observation was made by one recycle
system manufacturer contacted during this study. Recycle systems, thus
may not achieve the effluent quality possible with once-through systems
when treating comparable strength effluents.
7.* SLUDGE HANDLING AND DISPOSAL
Solid waste (sludge) is produced as a result of physical-chemical and/or
biological treatment of laundry wastewater. In a DAF system, floe formed by
coagulation is collected in the DAF unit, resulting in a sludge having a solids content
of 5% to 8% by weight. This sludge is composed of coagulant chemical precipitates
and pollutants removed from the wastewater. Biological sludges result from
microbial growth and decay. In the following section only solid waste from DAF is
discussed because no information was available on sludges resulting from the
biological treatment of laundry wastewater.
7.4.1 Sludge Dewatering
Sludges from DAF units are typically in a liquid state with a solids content of
5% to 8% by weight. Dewatering techniques serve to reduce the overall volume of
solid waste produced, converting sludge into a more solid form. Dewatering will
usually make handling and disposal of sludges easier and less costly for the laundry
operator. Certain laundries with DAF currently use rotary vacuum filters or screen
presses for dewatering purposes. A sludge cake with a solids content of between
20% and 30% is produced with these devices.
7.4.1.1 Rotary Vacuum Filters
A vacuum filter consists of a cylindrical rotating drum partially submerged in
a vat of sludge. Sludge adheres to a cloth or steel mesh filter that makes up the
drum surface. Vacuum imparted to the inside of the rotating drum draws water
from the sludge through the filter material to the drum interior where it collects
and is either discharged as final effluent or directed back to the equalization tank.
The resulting dewatered sludge (filter cake) is scraped from the filter and collected.
The ability of a rotary filter to dewater laundry sludge depends on the
following conditions:
o Type and concentration of contaminants in the laundry effluent being
treated,
o Type and quantity of chemicals used for physical-chemical treatment,
and
o Design capabilities of the dewatering equipment.
90
-------
Laundries currently employing rotary filters report sludge cakes having
between 20% and 30% solids by weight. In instances where laundry effluents have
high solvent concentrations it has been reported that the resulting sludges are
relatively more difficult to dewater by rotary vacuum filtration.
7.*. 1.2 Screw Presses
A screw press is used at one commercial laundry to dewater sludge from a
DAF unit. Before entering the press, sludge is conditioned by addition of a polymer
that chemically alters its characteristics, enhancing separation of water from solid
material. A rotating screw acts to compress the incoming sludge, squeezing out
water; the resulting sludge cake is approximately 20% solids by weight.
7A.2 Sludge Quantity
The amount of sludge produced as a result of DAF treatment of laundry
wastewater was estimated to determine the sludge disposal costs given in Section 8.
Based on the median concentrations of oil and grease and TS5 in industrial laundry
effluents, before and after treatment, it was assumed that a 90% reduction in the'ie
parameters was typical for a DAF. This assumption and respective coagulant feed
rates of 1,200 mg/1 and 1,800 mg/1 for industrial laundry wastewaters were used to
calculate sludge production. Solids content in sludge from a DAF unit was assumed
to be 5% solids by weight. Table 7-9 gives the production of DAF sludge and
dewatered sludge at various flowrates for industrial laundries.
7.*.3 Disposal Techniques
Most laundries operating DAF systems employ the services of an outside
contractor for disposal of sludge. The contractor may use a sanitary landfill or an
incinerator to achieve final disposal. It is reported from site surveys that present
contractors predominantly use sanitary landfills for final disposal of laundry sludges.
However, if laundry sludge is found to be hazardous as defined by the Resource
Conservation and Recovery Act (RCRA), then the sludge must be disposed of in
RCRA approved landfills.
91
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TABLE 7-9 SLUDGE QUANTITIES RESULTING FROM THE
PHYSICAL-CHEMICAL TREATMENT OF
INDUSTRIAL LAUNDRY WASTEWATER3
Sludge Production Dewatered
from DAF unit3 sludgeb
kg/day m3/day m^/day
(Ib/day) (yd3/day) (yd^/day)
2,300 (5,000) 46 (60) 9.0 (12)
1,400 (3,120) 28 (37) 6 (8)
680 (1,500) 14 (18) 3 (4)
400 (875) 7.6 (10) 1.5 (2)
170 (375) 3.4 (4.5) 0.8 (1)
57 (125) 1.1 (1.5) 0.2 (0.3)
12 (50) 0.5 (0.6) 0.07 (0.1)
aBased on sludge solids content of 5% by weight.
b&ased on sludge solids content of 25% by weight.
92
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SECTION 8
COSTS OF TREATMENT SYSTEMS
This section presents capital and annual cost estimates for treatment of
laundry wastewater. The treatment technologies selected for cost estimation
purposes are briefly reviewed. Capital and annual cost estimates for pretreatment
and direct discharge treatment of laundry wastewaters are presented in graphic and
tabular form. Selected flowrates based on industry data are used in the tables. The
costs are in fourth quarter, 197S dollars. The basis for capital and annual costs for
each component system is presented. Energy, sludge management, air pollution and
other nonwater quality environmental considerations are addressed.
Technologies for pretreatment and direct discharge treatment of laundry
wastewaters were discussed in Section 7. Technologies presently applied in the
laundries industry were selected for cost estimation purposes. Dissolved air
flotation (DAF) treatment was described as applicable technology for pretreatent of
laundry wastewaters. In addition, DAF plus biological treatment was described ELS
applicable technology for direct discharge treatment of laundry wastewater. The
DAF treatment systems considered incorporate chemical addition and floe-removal
techniques to remove pollutants. Trickling filters and stabilization ponds were the
biological treatment systems considered. Pollutant removal capabilities of DAF and
biological treatment systems were discussed in Section 7.
Differences in pollutant loadings affect operating costs but not capital costs
of DAF treatment systems; in addition they affect capital costs of treatment for
direct discharge. Typical pollutant loadings, as found in industrial laundries, were
used for cost estimation purposes.
8,1 CAPITAL AND ANNUAL TREATMENT COSTS ESTIMATE SUMMARY
Table 8-1 presents treatment technologies considered for cost estimation
purposes for the pretreatment and the direct discharge treatment of laundry
wastewaters. These technologies are DAF treatment for pretreatment, and DAF
plus biological treatment (either a stabilization pond or a trickling filter) for direct
discharge. These treatment systems are combinations of various alternatives that
affect capital costs, such as type of biological system.
Table 8-2 presents and summarizes, for selected flowrates, capital and annual
cost estimates for the pretreatment of laundry wastewater with DAF. Figure g-i
graphically presents total capital cost estimates versus flowrate while Figure 8-2
presents total annual costs versus flowrate for the pretreatment of laundry
wastewaters. Data points shown in the figures were developed from vendor quotes
and estimates for various flowrates.
Table 8-3 presents and summarizes, for selected flowrates, capital and annual
cost estimates for the direct discharge treatment of wastewaters with DAF and
either a stabilization pond or a trickling filter. Figure 8-3 presents graphically total
capital cost estimates versus flowrate while Figure 8-4 presents total annual cost
estimates versus flowrate. Total annual costs and total capital costs differ
significantly between DAF treatment with stabilization ponds and trickling filters
93
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TABLE 8-1. TREATMENT OPTIONS FOR LAUNDRY WASTEWATER5
Pretreatment Direct Discharge treatment
System
Physical-
chemical
Option Systems
DAF Physical-
chemical
plus
biological
Options*
(Physical-
chemical system
using DAF) plus
trickling filter or
stabilization
pond.
aOptions are combinations of various alternatives that affect capital costs.
94
-------
TABLE 8-2. CAPITAL AND ANNUAL TREATMENT COST ESTIMATES AND
TOTALS FOR PRETREATMENT OF LAUNDRY WASTEWATERS WITH DAF
VO
UI
Cost, 103
Flowrate, m'/day (I03 gpd)
Component
Total capital cost estimate:
Capital cost
Total1*
Total annual cost estimate:
Amortization
Chemicals
Sludge disposal
Electricity
Operating labor
Maintenance
Insurance
Monitoring
Technical support
Totalb
760
<200)
300
300
49
55
19
6.6
16
6.0
3.0
l.l
6.0
163
470
(125)
235
235
38
34
12
4.2
16
4.7
2. it
1.1
6.0
121
230
(60)
169
169
27
16
5.6
2.0
16
3.1
1.7
1.1
6.0
79
130
(35)
128
128
21
9.6
3.1
1.2
16
2.6
1.3
1.1
6.0
62
57
(15)
67.3
67.3
11.0
4.1
7.0
0.5
16
1.4
0.7
1.1
6.0
48
19
(5)
47.7
47.7
7.8
1.4
2.3
0.2
16
1.0
0.5
1.1
6.0
36
7.6
(2)
42.6
42.6
7.0
0.5
1.0
0.1
16
0.8
0.4
1.1
6.0
33
aFourth quarter, 1978 dollars.
^Totals shown may not correspond to added values due to rounding.
-------
10
(2> (3) (4) (51(6) (8) (10) (20)
I 1.
in
o
(40) (60) (80)(100) <200)
A fcifn All I.
en
o
a in
o o
a uio o
ooo o
FLOWRATE,
Figure 8-1,
Total capital cost estimates for pretreatraent of laundry wastewaters
with DAF.
-------
300
200
to-
rn
O
8
100
80
CO
50
4O
3O
20
10
(1)
* * L
* *
*
(2) (3) (4) (5){6) (8) (10)
(20) (40) (60) (80H100) (200)
l » » i t 1 i I—I—i_j
Ul
O
Ul
O
M ro
o in
f fUt 01 ^1 00
O 1SIO O O O
o oo o o o
FLOWRATE, m3/day (103 gpd)
Figure 0-2.
Total annual cost estimates for pretreatraent of laundry wastewaters
with DAF.
-------
TABLE 8-3. CAPITAL AND ANNUAL COST ESTIMATES AND TOTALS FOR TREATMENT OF
LAUNDRY WASTEWATERS FOR DIRECT DISCHARGE (WITH BIOLOGICAL TREATMENT)
Options and
flowrutes
m'/day
(10s gpd)
Trickling Pond
750 (200)
470 (125)
230 (60)
130 (35)
57 (15)
19 (5)
7.6 (2)
Stabilization Pond
760 (200)
470 (125)
230 (60)
130 (35)
57 (15)
19 (5)
7.6 (2)
Annual costs, 10* $a
Capital costs, 10s $a
Physical-
chemical
255
205
150
115
58
43
39
225
205
150
115
58
43
39
Biological
treatment
850
500
330
200
HO
95
90
330
230
130
90
55
30
25
Total
1,100
750
480
320
200
140
130
555
435
280
205
115
75
65
Amortization
Physical -
chemical
42
33
24
19
9.5
7.0
6.4
42
33
24
19
9.5
7.0
6.4
Biological
treatment
100
63
39
23
16
11
11
39
27
15
11
6.4
3.5
2.9
OMI
Physical-
chemical
111
80
51
41
37
28
26
no
80
51
41
37
28
26
Biological
treatment
51
32
20
12
8.4
5.7
5.4
34
24
17
13
9.2
6.7
6.2
t_
Totalb
300
210
130
95
70
50
50
225
165
105
84
62
45
42
aFourth quartert 1978 dollars.
^Tables shown may not correspond to added values due to rounding.
-------
VD
vO
TRICKLING FILTER
STABILIZATION POND
100
(1)
(2) (3) (4) (5) (6) (0) (10)
(20)
(40) (60) (80M100)
(200)
M
O
Ul O
o o
f- Ul OT ^ OB
m o o o o
o o o o o
FLOWRATE, rn^/day (103 gpd)
Figure 8-3.
Total capital cost estimates for direct rtJscharqe treatment with
L'AF treatment plus a trickling filter or a stabilization pond.
-------
o
o
300
200
TRICKLING FILTER
STABILIZATION POND
(2)
(3) (4) (5|(6) (8)(10)
(20)
(40) (60) (80)(100)
(200)
I I
M
O
in
o
o
o
•f f in
o in o
en vj QO
o o o
o o o
FLOWRATE, m3/«3ay (103 gpd)
Figure 8-4. Total annual cost estimates for direct discharge treatment of laundry
wastewaters.
-------
because of the significant differences be:veen the capital and annual costs between
stabilization ponds and trickling filters.
8.2 COST BASIS
Total capital cost estimates include equipment costs, freight charges, site
preparation costs, installation costs, indirect charges for engineering and
construction, startup costs, and contingency allowance. Estimates do not include
allowances for working capital. Working capital costs will be insignificant because
large "product" and raw material inventories are not maintained.
Capital costs estimates were developed separately for DAF treatment
systems and biological treatment systems.
All costs are given in fourth quarter 197S dollars. Costs are based on
information, quotes, and estimates from vendors, industry associations, and the
literature. The data were aggregated and averaged where possible.
S.2.1 Dissolved Air Rotation Treatment Systems
A DAF treatment system was selected for cost estimation as the pretreatment
system for laundry wastewaters discharged to POTW's and as part of the treatment
system for the direct discharge of laundry wastewaters to receiving waters. The
DAF treatment system considered incorporates chemical addition and floe-removal
techniques to remove pollutants.
8.2.1.1 Capital Cost Estimate
Capital costs include equipment costs, freight charges, site preparation costs,
installation costs, indirect charges for engineering and construction, start-up
charges, and a 10% contingency allowance. The allowance was used to cover
potential price increases, construction delays, and other unforeseen expenses.
Allowance for working capital was not included because it will be insignificant.
The data points were determined using vendor-supplied quotes and estimates
for equipment, freight, installation, and start-up expenses. These vendors specialize
in treatment systems for laundries, and the majority of the systems offered are
turnkey systems or packaged, skid-mounted systems. Therefore, no component cost
breakdown (such as equipment, piping, installation, engineering, etc.) is possible
because of the nature of the quotes and estimates used.
8.2.1.2 Annual Treatment Cost Estimates
Annual costs Include amortization, operating, maintenance, insurance,
monitoring, and technical support charges.
Amortization - The annual amortization was determined from the total capital
cost estimate using the following equation:
101
-------
Annual amortization, $/yr = CRF x A (8-0
where CRF = capital recovery factor, 0.163 (86)
A = capital cost estimate, $
A 10% annual interest rate, 10-year equipment life, and no salvage value were
assumed.
Chemical Costs - Chemical dosage rates for various systems of chemical
additives were evaluated following input from industry. These rates along with
literature sources (57), chemical supply vendors' estimates, treatment system
vendors' estimates, and chemical costs for systems in operation at laundries were
aggregated to produce a range of chemical costs, from $0.063/m* of water treated
to $0.«/m3 Of water treated ($0.2^/1,000 gal. of water treated to $1.62/1,000 gal.
of water treated).
The most significant factor in determining the range of chemical costs was the
variations in the cost per kilogram (pound) or cubic meter (gallon) of the chemical to
be used. Therefore, local prevailing prices for chemicals will affect the chemical
cost per unit of water treated more significantly than will the system of chemical
additives chosen.
The average chemical costs of $0.28/m3 of water treated ($1.05/1,000 gal. of
water treated) were developed by averaging the chemical costs incurred by
industrial laundries and linen supply laundries, respectively, having DAF treatment
systems.
Figure 8-5 presents the relationship between annual chemical costs and
flowrates for the DAF treatment of laundry wastewaters. Based on laundry industry
data, 260 operating days/year are used to calculate annual charges.
Sludge Disposal Costs - Sludge disposal costs include the cost for the removal
of the sludge from laundry premises and the hauling of sludge to an approved
landfill. The sludge may or may not be dewatered depending on the economics of
dewatering. Disposal may or may not be performed by contract labor. Costs were
compiled from estimates and costs provided by the laundries industry, costs incurred
by laundries operating DAF treatment systems, and the literature (58).
Costs for sludge disposal range from $0.018/m3 of sludge to $65/m3 of sludge
($0.01<*/yd3 of sludge to $50/yd3 of sludge) with an average cost of $7.SO/nr> of
sludge (56/yd3 Of sludge).
Daily sludge generation rates are presented in Figure 8-6. The information
was developed in Section 7. Dewatering of sludge to reduce volume, and therefore
disposal charges, will be economical when the annual savings from the reducea
volume of sludge for disposal equals or exceeds the annual amortized cost of
dewatering equipment. This will be the lowest economical flowrate for sludge
dewatering. Labor and maintenance charges are not specifically quantifiable from
the estimates supplied by the laundries having these treatment systems. Graprung
the annual amortized equipment costs and the annual disposal charge savings for
dewatered sludge shows that sludge dewatering becomes economical at 6* m-Vday
102
-------
I 1
(4) (61 (a) (10)
(20
.! J__L I 1 L-L.!
(4JJ (60i (SCI (ICO) (2COJ
> i it i i i i i i
zo
too
uo
sc xc
Figure 8-5. Annual chemical costs for DAJ treatment of laundry
wastewaters.
103
-------
ID
(2)
(4) (6) (8) (10)
(20)
(40) (601(80)1100)
i i i i i i
(200)
100
IX 20190X0
FLOWRATE,m3/day(103SP
-------
(17,000 gpd), as shown in Figure 8-7. Based on laundry industry data, 260 operating
days/year are used to calculate annual costs.
Figure 8-8 presents annual sludge disposal cost estimates versus flowrate for
the DAF treatment of laundry waste waters. The average cost for sludge disposal is
$O.W/m3 of water treated ($1.80/1,000 gal. of water treated) for sludge not
dewatered and $0.09
-------
100
'80
60
40
20
10
8
6
4
8 2
II
0.8
0.6
0.4
0.2
0.1
(1)
DISPOSAL
SAVINGS
FOR
DEWATERED
SLUDGE
AMORTIZED COST OF /
SLUDGE DEWATER ING
FLOWRATES ABOVE WHICH
SLUDGE DEWATERING IS
ECONOMICALLY JUSTIFIED
J—I \ 1 1 t I
i i i » i t
(21
(4) (6) (8) (10)
(20)
140) (60) (80) (100) (200)
i 11
i i
iw as ao »
R.OWRATE.m'wayllo'spd)
Figure 8-7.
Annual sludge disposal savings for dewatered
sludge versus annual amortized cost of
sludge dewatering equipment.
106
-------
100
80
60
40
20
10
8
1/1
S 2
1
as
0.6
0.4
0.2
0.1
(1)
WITHOUT
DEWATERING
FLOIVRATES WHERE THE
ANNUAL AMORTIZED
COST OF SLUOGE
DEWATERING EQUIPMENT
EQUALS THE SAVINGS IN
YEARLY DISPOSAL COST
tSEE PREVIOUS FIGURE)
THEREFORE ECONOMICALLY
JUSTIFYING THE USE OF
SLUDGE DEWATERING
WITH
DEWATERING
' i I i i i i
L
' i i i i i i i
(2) (41 (6) 18) UQ)
i
(20)
(40) (60) (80X100) (2CO)
j_
i
uo MO so so
aOWHATE,m3Way(103gpd)
Figure 6-8. Annual sludge disposal* costs for DAJ treatment of
laundry wastewaters.
Only sludge disposal costs are shown on graph.
ing equipment cost not included.
Sludge dewater-
107
-------
variable ranging from zero dollars pe.:c for the service, ii it is performed by
employees in addition to their other duties, to perhaps 5% to 10% of the capital
cost.
Technical support costs were estimated to be $6,000 annually for DAF
treatment of laundry wastewaters; this is independent of flowrate.
Summary of Annual DAF Treatment Cost Estimates - Table 8-4 summarizes
the annual cost for the DAF treatment of laundry wastewaters.
JL2.2- Biological Treatment Systems
Biological treatment systems were selected for cost estimation as part of the
direct discharge treatment technology for laundry wastewaters. Biological and DAF
treatment together comprise the direct discharge treatment for laundry
wastewaters.
Trickling filters and aerobic-anaerobic stabilization ponds were the biological
systems selected.
Trickling Filters
8.2.2.1.1 Capital Cost Estimate
Capital costs include equipment costs, freight charges, installation costs,
indirect charges, start-up charges, and contingency. Working capital is not included
because it is insignificant.
Major equipment component costs, such as filter media, rotary distributor,
underdrain material, containment panels, holding tank, and clarification tank were
obtained from vendors. The delivered, installed cost of this equipment was
multiplied by a factor of 1.75 to estimate the additional piping, instrumentation,
start-up, indirect, and contingency charges for an add-on system to the physical-
chemical treatment system. A factor of 2.00 was used to estimate the total capital
cost of an independent treatment system. Figure 8-9 illustrates the capital costs
versus flowrate relationship for the trickling filter treatment of laundry
wastewaters.
8.2.2.1.2 Annual Cost Estimate
Amortization - Annual costs for trickling filters include amortization,
operating, maintenance, and insurance charges. Figure 8-10 illustrates the
relationship between annual costs and flowrates. The annual amortization was
determined using Equation 8-1 with capital recovery factor equal to 0.117 (62). A
10% annual interest rate, 20-year equipment life, and no salvage value were
assumed.
Operating. Maintenance, and Insurance Charges - Operating, maintenance, and
insurance (OM1) charges were estimated as 6% annually of the trickling filter capital
cost based on literature sources (39,60).
108
-------
TABLE 8-4 SUMMARY OF ANNUAL TREATMENT COST ESTIMATES FOR
DAF TREATMENT OF LAUNDRY WA5TEWATER
Component costs
Annual cost
Amortization
Chemicals
Sludge disposal, dewatered
Sludge disposal, undewatered
Electricity
Operating labor
Maintenance
Insurance
Monitoring
Technical support
0.163 (capital cost)
($0.2S/m3)a(flow)b
($0.094m3)c(flow)b
($0.48/m3)d(flow)b
($0.03/m3)e(flow)b
$16,000
Q.02(capital cost)
0.01 (capital cost)
$1,100
$6,000
a Range of $0.063/m3 of water treated to $0.43/m3 of water treated.
b Flow equals m3/day times 260 operating days^year.
c Range of $0.00012/m3 of water treated to $0.<*5/m3 01 water treated and
$0.00022/m3 of water treated to $0.78/m3 of water treated, respectively.
d Range of $0.00061/m3 of water treated to $220/m3 of water treated, and
$0.0011/m^ of water treated to $4.00/m3, respectively.
e Range of $0.02l/m3 of water treated to $0.066/m3 of water treated.
f Range of $0.032/m3 of water treated to $0.32/m3 of water treated.
S Range of $0.008/m3 of water treated to $0.*9/m3 Of water treated.
h Range up to $0.87/m3 of water treated.
109
-------
1,000
800 h
600
400
200
to
i—
i/>
O
o
100
80
60
(1)
INDEPENDENT
SYSTEM
ADD-ON
SYSTEM
' i i i i i
i i i i
(2) (3) 14) (6) (8) (10)
(20)
(40) (60) (80) (100) (200)
i i I LJJ 1—L_J
20
100
150 200
300 40Q4SOWO 600100 BOO
ROWRATE, m3/day UO3 gpd)
Figure 8-9. Capital cost for trickling filter treatment of laundry wastewaters.
-------
200
CO
O
o
100
80
60
40
20
10
INDEPENDENT
SYSTEM
ADD-ON
SYSTEM
i i i i
(1)
(2) (3) (4) (6) (8) (10)
(20)
(40) (60) (80) (100) (200)
I I
100
130 200
300 400*0500600700800
Figure 8-10.
ROWRATE,m3/day(103gpd)
Total annual costs for trickling filter
treatment of laundry wastewaters.
-------
S.2.2.2 Aerobic-Anaerobic Stabilization F>v :'s
8.2.2.2.1 Capital Cost Estimate
Capital costs include the items previously discussed. The costs of major
components such as aerators, concrete work, pond liner, excavation, and a
chjorinator were obtained from vendors. The cost of these items was multiplied by
a factor of 2.00 lor an add-on to DAP treatment, and by a factor of 2.25 for an
independent system to estimate additional charges for piping, instrumentation,
installation, indirects, etc. Figure 8-11 illustrates the capital cost versus flowrate
relationship.
8.2.2.2.2 Annual Cost Estimate
Annual costs of stabilization ponds versus ilowrates are illustrated in Figure
8-12.
Amortization - The annual amortization was determined using Equation 8-1
with capital recovery factor equal to 0.117. A 10% annual interest rate, 20-year
equipment life, and no salvage value were assumed.
Operating, Maintenance, and Insurance Charges - Operating, maintenance, and
insurance charges were estimated as 10% of the stabilization pond capital cost
based on literature sources (60,61).
8.3 ENERGY CONSUMPTION
The total annual electricity consumption for pretreatment in the subcategories
for which pretreatment may be necessary, industrial laundry and linen supply
subcategories, was estimated and is presented in Table 8-5. The electricity usage
per cubic meter of water treated (per 1,000 gal of water treated) was determined
from the cost of electricity for pretreatment ($0.13/1,000 gal as previously
developed) and an estimate of the average unit cost for electricity ($0.0*/KWH).
An estimate for the electricity consumption in both subcategories from an
industry trade association is 80 M3/kg of laundry (10 KWH/100 Ib of laundry). Using
the same information, estimates of electricity consumption were developed and are
presented in Table 8-6. The increase in electricity usage if all laundries were to
install pretreatment systems (and none presently had them) is also estimated. The
increase in electricity consumption in industrial laundries and linen supplies would
be 20% and 17%, respectively.
Of course, these estimates are only crude approximations of the actual
increases in electrical consumption that would be incurred if all industrial laundries
and linen supplies were to install pretreatment systems. It is also important to note
that these percent increases apply to electrical power only, and not to total energy
consumption (which includes fuel for steam generation).
8.* SLUDGE MANAGEMENT
Present sludge disposal practices consist of contracting with a hauler/landfill
operator to provide for disposal. The sludge may or may not be dewatered before
112
-------
INDEPENDENT
SYSTEM
Ill
(21
(3) (4) (5) (6) (8) (10)
(401 160) (BO) (lOOt
(200)
J—L.
100
no wo
too
FLOWRA1E, m3/(lay U03qpd)
Figure 8-ia
Capital costs for stabilization pond
treatment of laundry wastewaters.
-------
o
»—«
U-T
O
U
100
80
60
40
20
10
8
6
INDEPENDENT
SYSTEM
ADD-ON
SYSTEM
i i i t i
t t I I I I t
(1)
(2) (3) (4) (6) (SJ(IO)
(20)
140) (60) (SO)(ICO) I2CO
SO
100
IK 200
30;
Figure 8-12.
Total annual costs for stabilization pond
treatment of 'laundry wastewaters.
114
-------
TABLE 8-5. ANNUAL ELECTRICITY CONSUMPTION
BY PRETREATMENT
Subcategory
Industrial
laundry
Linen
supply
Approximate
number of
indirect
dischargers
1,000
1,300
Annual electricity
consumption by
treatment,
P3 (10s KWH)
0.23 (64)
0.55 (150)
Electricity usage
per 1,000 gal of
water treated,
M3 (KWH)
12 (3.3)
12 (3.3)
TABLE 8-6. ANNUAL ELECTRICITY CONSUMPTION
AT LAUNDRIES
Subcategory
Industrial
laundry
Linen supply
Number of
indirect
dischargers
1,000
1,300
Annual
consumption
P3/y(106KWy)
1.2 (320)
3.2 (890)
Increase in
consumption
if pretreatment
technology used,
percent
20
17
115
-------
disposal. Presently, screw presses and vacuum filters are used to dewater sludge.
The quantities of sludge generated per year by pretreatment are estimated in Table
8-7, assuming all laundries installed these systems and none presently had them, and
that all sludge is either dewatered or all is not dewatered. Using the amount of
sludge generated per 1,000 gallons of water treated, the average number of gallons
of water used per laundry per year, and the number of indirect dischargers in the
subcategory, the amount of sludge generated per year for subcategories in which
pretreatment may be necessary was estimated.
New developments in sludge handling practices are underway in the Chicago
area. Recent legislation has required that the generation and disposal of industrial
waste be monitored by a set of forms (manifests). Monitoring is required from the
time of sludge generation to its ultimate disposal, and copies of the forms are
provided to each handler and to the sanitary district at each step. The system has
not been in effect for a time sufficient to permit the assessment of costs incurred
by industry.
The sludge composition is discussed in Section 7 and corresponds to pollutants
removed from the laundry wastewater plus additive chemicals.
W OTHER NONWATER QUALITY ASPECTS
Presently, there are no other known, significant, nonwater quality
environmental impacts in terms of noise, radiation, or health from the selected
treatment technologies.
The nonwater quality aspects relating to air pollution that do not concern just
the automatic and other laundries industry are 1) a possible stripping of volatile
toxic pollutants in the treatment systems, and 2) release of air pollutants from
sludge incineration. Release of volatile toxic compounds by stripping is
theoretically possible, but it has not been measured at this time. The possible
impact on air quality has not been evaluated. The second aspect to be considered is
the release of air pollutants, especially heavy metals, as paniculate or vapor if the
sludge produced from laundry wastewater treatment is incinerated. This is not
presently practiced as a disposal method, and the possible air quality impact has not
been evaluated.
116
-------
TABLE 8-7 AMOUNT OF SLUDGE GENERATED PER YEAR BY
PRETREATMENT
Subcategory
Number of
indirect
dischargers
Sludge generated
m3/m3 of water
treated (yd3 1,000
gal. of water
treated
m3/yr
(106 yd^/yr)
Industrial
laundry
Linen
supply
1,000
1,300
0.061a
(0.30)
0.012b
(0.060)
(0.17)
0.0069^
(0.03ft)
t.5
(6.0)
0.91
(1.2)
6.2
(8.1)
(1.6)
aSludge not dewatered.
^Sludge dewatered.
117
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SECTION 9
SELECTION OF APPROPRIATE CONTROL AND TREATMENT TECHNOLOGY
AND DEVELOPMENT OF PERFORMANCE LEVELS
In the industrial laundry and linen supply subcategories all plants but one are
known to discharge to POTWs. For reasons listed in Section 6, the Agency has
decided not to impose regulations upon these two subcategories, but to present the
results of this study as guidance to writers of permits and requirements at the local
level.
9.1 GUIDANCE FOR PRETREATMENT
Achievable performance by dissolved air flotation is presented in Table 9-1.
The methodology used to determine the achievable performance is presented in the
following subsections.
9.1.1 Technology Basis
The treatment technology basis for industrial and linen supply laundries is
dissolved air flotation (DAF). The technology includes flow equalization, chemical
addition, and floe removal. Although only a limited number of laundry facilities
currently pretreat their wastewaters, DAF is the most commonly applied technology
in the industry. The DAF system has shown to be effective in reducing toxic as well
as conventional pollutants.
The Agency investigated other technologies potentially applicable for the
treatment of laundry wastewaters. These technologies, which included
ultrafiltration, electrocoagulation, filtration and carbon adsorption, were rejected
because of limited performance data or for technological reasons. Filtration and
adsorption technologies were rejected primarily because the oil and grease found in
laundry wastes tend to clog or bind such units.
9.1.2 Pollutants
The primary toxic pollutants studied for achievable performance are
chromium, copper, lead, and zinc. These four metals are found most frequently and
at the highest concentrations in both industrial laundry and linen supply
wastewaters.
The Agency considered estimating achievable removals for major toxic
organics but decided not to for the following reasons. Although DAF effectively
removes organics, it is difficult to quantify that removal because it is often related
to the removal of oil and grease. In addition, technologies that might further
remove organics following DAF, and possibly allow for a numerical limitation were
rejected for technological reasons based on the characteristics of DAF effluent.
9.1.3 Statistical Methodology
Statistical analyses were performed on the laboratory measurements of four
toxic metals; copper, chromium, lead, and zinc found in the treated effluent waste
stream. Statistical calculations for variability factors of daily measurements for
these parameters, are included herein, as well as probability performance curves for
30-day averages.
118
-------
Data -Sources - Data used in the development of achievable performance for
industrial and linen supply laundries are from the sampling and analysis of
wastewater discharges at eight industrial laundries currently operating DAF
treatment systems. Analytical data are presented in Appendix A. A total of 33
data points (daily samples) were used for statistical analyses; 23 from one laundry
and ten from seven other laundries.
Prestatistical Data Treatment - In recording of actual data, certain- data
values were entered as "less than" detectability limits. In these cases, the sample of
monitoring data has been "censored" in the process of data recording since only the
threshold value has been retained (i.e., if a pollutant concentration was reported as
<0.050 mg/l, the value of 0.050 mg/1 was used). In the statistical analysis of
monitoring data, censored data values were included with measured values in the
sample. This practice provides a reasonable approach, both for assessing industry's
capability to perform and environmental concerns for valid pollutant limitations.
Since censoring was done for "less than" bounds, any bias from their inclusion would
cause a slight increase in the long-term average, moderately affecting (in the
direction of leniency toward industry) the estimate of long-term average pollution
levels.
The measurements obtained for each parameter were screened by statistical
methods for spurious or non-representative values. For this test of outliers as well
as other statistical analyses reported herein daily observations of pollutant levels
were assumed to follow the lognormal distribution. Under this assumption the
logarithms of these measurements follow a normal distribution.
The extreme values, i.e., maximum and minimum, were subjected to a
students' t-test for outliers. The test consisted of calculating a t-statistic, given by:
t = max ((Xmax - y)/Sy, (y - XminJ/Sy)
where:
/max is the logarithm of the datum corresponding to the largest pollutant
measurement, and Xmin is the logarithm of the smallest.
y is the arithmetic mean of the sample logarithms.
Sy is the standard deviation of the sample logarithms.
Where the calculated t-statistic exceeded the 99th percentile of the student's
t distribution appropriate for the particular sample size, that value was rejected as
not belonging to the sample. Whenever an extreme value, either maximum or
minimum was rejected in the test for outliers, the sample statistics were
recomputed with the remaining data, and the screening for outliers performed once
more. The procedure for computing statistics, screening for outliers, rejection of
outliers, if any, and recomputation of statistics continued iteratively until no
outliers were found.
Statistical Analysis - Standard statistical measures of pollution levels in DAF-
treated effluents are tabulated and recorded in Tables 9-2 - 9-4. These include
minimum (Min), arithmetic sample average (Avg), sample maximum (Max),
arithmetic standard deviation (Stdv), and sample coefficient of variation (C.Var).
119
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TABLE 9-1. ACHIEVABLE PERFORMANCE BY D.A.F.
Pollutant
Chromium
Copper
Lead
Zinc
M^M^^^^^M^^^BVM^BBWHM^M^HB
Estimated
Long-Term
Average
mg/1
0.18
0.7*
0.93
0.7*
Daily
Variability
Factor(l)
4.0
2.7
3.7
4.4
Proposed
Limitations
mg/1
24-hr, max.
0.74
1.5
3.7
2.9
30-day avg.
0.22
0.93
1.7
1.1
(1) Daily variability factor is the ratio of the estimated 99th percentile to the
estimated long-term average.
TABLE 9-2 STATISTICAL SUMMARY OF TREATMENT DATA FOR
PLANT Z
Parameter (mg/1)
Cu
Cr(T)
Pb
Zn
No
19
18
19
19
Min
0.50
0.04
0.04
0.09
Avg
0.86
0.13.
0.98
0.77
Max
1.32
0.20
2.48
2.15
Stvd
0.23
0.04
0.73
0.60
C.Var
0.27
0.34
0.74
0.77
120
-------
TABLE 9-3. STATISTICAL SUMMARY OF TREATMENT DATA FOR SEVEN
INDUSTRIAL LAUNDRIES
Parameter (mg/1)
Cu
Cr(T)
Pb
Zn
TABLE 9-4
Parameter (mg/1)
Cu
Cr(T)
Pb
Zn
No
9
8
9
&
STATISTICAL
INDUSTRIAL
No
28
26
28
27
Min
0.09
0.03
0.02
0.06
Avg
0.3
-------
POLLUTANT: Copper
Proposed Daily Maximum Limitation (mg/1)
1.5
All Data
Plant "Z"
Long Term Average
Standard Deviation of Daily Measurements
99th percentile (Z=2.33)
Number of Observations
0.74
0.3425
1.78
2S
0.86
0.2334
1.54
19
00
£
o
CJ
u
U
LOWER CONFIDENCE BAND
UPPER CONFIDENCE BAND
DATA
Percentage
Figure 9-1. Cumulative Distribution of Daily Concentrations from Industrial
Laundry Treated Effluent
123
-------
POLLUTANT: Chromium
Proposed Daily Maximum Limitation (mg/1)
0.74
All Data
Plant "Z"
Long Term Average
Standard Deviation of Daily Measurements
99th percentile (Z=2.33)
Number of Observations
0.18
0.1474
.74
26
0.13
0.0438
.26
IS
o
V
-------
POLLUTANT: Zinc
Proposed Daily Maximum Limitation (mg/1)
2.9
All Data
Plant "Z"
Long Term Average
Standard Deviation of Daily Measurements
99th percentiJe (Z=2.33)
Number of Observations
0.7f
0.5752
2.90
27
0.87
0.5972
3.01
19
oo
£
o
~
ro
L.
«-
V
I
o
u
UPPER CC»JFIDENCI BAND
Percentage
Figure 9-4. Cumulative Distribution of Daily Concentrations from Industrial
Laundry Treated Effluent
126
-------
In the analysis of daily data, tne innerent variability of measured pollutant
levels in the effluent stream from the laundry industry must be incorporated in
calculating upper limits for daily pollutant discharge levels. Even well treated and
controlled plants may experience some days when atypicaliy high level of pollutant
discharge is present in their waste stream. Such variations may be due to a variety
of factors, such as short-term maladjustments in treatment facilities, variation in
flow, or pollutant load, or changes in the influent stream. To allow for this
variability, performance standards must necessarily be set above the plant's long-
term average performance and occasional, infrequent excessive discharges
permitted. Since pollutant concentration is often expressed in terms of average
level, it is convenient to describe standards of performance and allow variability in
term of multiples of this average. Such a method of computing limitation standards
as multiples of average level performance is used. The ratio of the pollutant
performance level to the estimated long-term average is commonly called the
"variability factor".
This factor is useful with lognormally distributed pollutant levels because its
value is independent of the long-term average, depending only upon the day-to-day-
variability of the process and the expected number of excessive discharge periods.
For a lognormal population, the variability factor (P/A), the performance standard
P, and the long-term average A, are related by:
ln(P/A) = S'(Z - S'/2)
where:
1. "In" represent the natural logarithm (base e) of a numerical quantity.
2. S' is the estimated standard deviation of the logarithms of pollutant level
measurements.
3. Z is a factor derived from the standard normal distribution. Z is chosen
as Z = 2.33 so as to give performance limitations which provide a balance
between appropriate consideration of day to day variation in a properly
operating plant and the necessity to insure that a plant is functioning
properly.
This Z-value corresponds to the 99th percentiie of the lognormal distribution
meaning that only 1 percent of the pollutant observations taken from a plant with
proper operation of treatment facilities would be greater than the performance
standard, P. This percentiie is equivalent to allowing a plant in normal operation 3
to * exceedances per year.
Calculation of Variability Factors
As mentioned above, statistical analysis of daily pollution level measurements
was based on the assumption that these data, (XI, X2,...Xn), follow a lognormal
distribution. Following this assumption, if Yi=ln(Xi), where ln(Xi) represents the
natural logarithm or log base e of the pollution measurements,then the Yi; i=l,2,...n
are each normally distributed. If A' and S1 are the mean and standard deviation of
Y=ln(X) respectively, then the probability of k percent that an individual Y will not
exceed A'+ZS', where Z is the k-th percentiie of the standard normal distribution,
e.g. 2-2.33, Is the 99-th percentiie of the standard normal distribution. It follows
127
-------
that A'+Z5' is the natural logarithm of the k-th percentile of X and that the
probability is k percent that X will not exceed a performance standard P=
exp(A'+ZS')^ It is also known that the average value of X is A= exp(A'+S'(SY2)). The
variability factor VF, is obtained by dividing P by A, hence,
VF * P/A = exp(5'(Z - S'/2)), and
ln(VF) = ln(P/A) = S'(Z - S'/2)
To estimate the VF for a particular set of monitoring data, 5' may be
calculated as the square root of ln(1.0 + (CV)2), where the sample coefficient of
variation, CV = S/X, is the ratio of sample standard deviation to sample average.
Example Calculation of Variability Factors for 24-Hour Data
Given the following descriptive statistics for a particular parameter, as might
be found for copper (mg/1) in Table 9-3.
No. Min Avg Max Stdv CV
2l" 0.09 0.69 1.32 0.34 0.49
Calculate the estimated standard deviation of logarithms
(S1)2 = In (1.0+ 0.492) = 0.219
5' = 0.468
Then
ln(P/A) = 0.468(2.33 - 0.468/2) = 0.981
The variability Factor VF is,
VF = P/A = exp (0.981) = 2.67
The performance standard P;
P = A(VF) = A(P/A) = (0.69X2.67) = 1.84 mg/1
The statistical interpretation of P, the performance standard, is that one
estimates that 99 percent of the daily pollution level measurements will not exceed
P. For large data sets, P is roughly equivalent to an upper 99 percent confidence
bound for an individual daily measurement.
Graphs of the cumulative distribution of sample results for each of these four
toxic metals being regulated are given in Figures 9-1 through 9-4. These graphs plot
cumulative relative frequency in the sample vs logarithm of pollutant concentration,
and are so scaled that a lognormally distributed variable plots as a straight line.
128
-------
ASSUMPTIONS CONCERNING 30-DAY AVERAGE POLLUTANT LEVEL
MEASUREMENTS
Although individual pollution concentration measurements are assumed
lognormally distributed, that distribution does not extend to the statistical behavior
of averages, in this case where 30-day averages are to be used. However, if
averages are taken over a "reasonably large" number of days, a statistical principle,
the Central Limit theorem, assures that probabilities pertaining to such averages
may be computed using the normal probability distribution. A 30-day average
contains enough individual daily measurements to insure that the normal probability
performance, even when daily values are lognormally distributed.
To assess the treatability level for the industrial laundry treatment technology
of DAF, the "probability performance" was calculated for each parameter in the
treated effluent stream. This quantity is the probability that a given stream will
have a 30-day average pollutant level (mg/1) that is within or less than a given level.
This amounts to the probability that a plant employing the proposed treatment will
produce a 30-day average concentration less than the corresponding level. Where a
pollutant discharge level is measured by the average concentration in thirty
individual daily measurements (the 30-day average), the probability performance is
the estimate of the proportion or fraction of the 30-day averages that will be less
than or equal to the given pollutant concentration.
COMPUTATIONAL PROCEDURES FOR ESTIMATES OF 30-DAY AVERAGE
PERFORMANCE
To compute the maximum likelihood estimates (MLE's) of probability
performance, it is necessary to compute the MLE's of the long-term average
pollution level and the long-term standard deviation of pollution level using
logarithms of the individual measurements of data. The maximum likelihood
estimates of the mean logarithm and standard deviation of logarithms are done using
standard statistical formulae.
These estimates are computed and used to obtain the MLE's of the long-term
average, A, and long-term standard deviation, 5, of the pollutant concentration.
Dividing the estimated long-term standard deviation, 5, by the square root of the
number of days (30) in the average, gives S*. the estimated standard error of the 30-
day average, and which can be used in computing probability performance. For any
pollutant level, P, the estimated probability performance, is computed as:
Probability (30-day average does not exceed P) = Pr(z)
where z = (P-AJ/S*
and Pr(z) = probability that a standardized normal value does not exceed z.
Included with the technical analysis of each toxic metal are the probability
performance curves, Figures 9-5 through 9-S and estimates of long-term averages
for each parameter. Note that the estimate of long-term pollution average is
obtained by maximum likelihood methods from the lognormal distribution and does
not necessarily equal the sample arithmetic average given in Tables 9-2 to 9-4.
129
-------
POLLUTANT: Copper
Proposed Maximum 30-Day Average (mg/1)
0.93
Estimated Long Term Average
Standard Error of the 30-Day Average
95th percentile (Z=1.64)
Number of Observations
All Data
0.7*
0.1095
0.92
28
Plant "Z"
O.S6
0.042
0.93
19
1.0
.2 °-9
u
0.8
V
>- u
*%
c-- 0.6
< (J
Estimated Probability That
Average Does Not Exceed a
o o o o o o
• •••••
o i-« K> u* •** en
y
S
?
0
7
.6
I
/
IA
J
/
MT
.
/
0
2
/
/
•
/
/
.7
— -«
(
/
^
/
i
/
/
b
^
/'
/
/
4
1
l/
f
j
/
h
•-,
^i
f
/
L
r^
/
ALL
0.8 0.
^
^^j
s=1
DATA
9 1
••
.0 1
.1
Concentration (mg/1)
Figure 9-5. Estimated Performance of Proposed DAF Treatment
130
-------
POLLUTANT: Chromium
Proposed Maximum 30-Day Average (mg/1)
0.22
All Data Plant "Z"
Estimated Long Term Average 0.18 0.13
Standard Error of the 30-Day Average 0.0253 0.0096
95th percentile (Z=1.64) 0.22 0.15
Number of Observations 26 18
Estimated Probability That Any 30-Day
Average Does Not Exceed a Given Concentration
O OOOOO OOOM
* ..••• •• ••
H NJUJ .u ui cr> j co u> o
^
^
;
/
2
0.
/
/
i —
1
1
1
?
1
1
1
**»•
K-"
J
t
/
^
^ *
i/
/
i~
/
/
S~\
1
I
1
- .PLANT Z
^
/
\
£
'
/
2
y
/
/
/
£
/
k
Z
7
i
^
/
/
i
LL DATA
12 0.14 0.16 0.18 0.;
>
^
/
x4
>o o.:
^
k
^^-
S»
•^
>2
Concentration (mg/1)
Figure 9-6. Estimated Performance of Proposed DAF Treatment
131
-------
POLLUTANT: Lead
Proposed Maximum 30-Day Average (mg/1)
1.7
Estimated Long Term Average
Standard Error of the 30-Day Average
95th percentile (Z=1.6<0
Number of Observations
All Data
0.93
0.4615
1.69
28
Plant "Z"
1.15
0.3121
1.66
19
3-Day
Concentration
o o OH
• • • •
-J CO U> 0
f\ C
£> 0.6
. o
= tu 0.4
13 *-
m o
•S2 0.3
t- f
"2 Q n ?
v U . ^-
*•* flj
« gi,
J2
tS Si 0.1
ID ^
^
^
^
.
^
^f
ALL
•
/
J
«^*I
°'° 0.
/
L
^
1
DATA 1
;
r
^
7
5
/
/
[
/
j
/
/
f
/
/
2
)
i
I
/
Z
3
*
j
/
/
/
«_
^
/
/
/
— —
/
V
f
x
r
j
?
-PLANT
^
Z
1.0 1.5
?2
2.
^^
0 2.
5
3.0
Concentration (mg/1)
Figure 9-7. Estimated Performance of Proposed DAF Treatment
132
-------
POLLUTANT: Zinc
Proposed Maximum 30-Day Average (mg/1)
1.1
All Data Plant "Z"
Estimated Long Term Average 0.74 0.87
Standard Error of the 30-Day Average 0.2113 0.2142
95th percentile (Z= 1.64) 1.09 1.22
Number of Observations 27 19
1.0
c.
% 0.9
id
t_
5 0.8
>• <->
JO c
O o
ciu 0.7
<*> c
rw V
c >
< (3 0.6
£ g 0.5
>N U
••- X
Estimated Probabi
Average Does Not
o o o o c
• • . « .
O M W LJ *
ALL
^
^X
DATA
/
?
\S\
0
/
/
1
I
/
/
I
/
— »•
/
/
12
/I ,
1
j
/
/
/
/
1
2
/
/
;
_
2
X
1
/
^
* !
•^-
>^
-PLANT
x*
Z
i
.5 1.0 1.5 2.0 2.5
Concentration (mg/1)
Figure 9-8. Estimated Performance of Proposed DAF Treatment
133
-------
Where a parameter curve is quite "steep", i.e., for those parameters that show
a sharp increase in probability (of a 30-day average not exceeding a given value) for
a small increase in pollution concentration, this is primarily due to a relatively small
coefficient of variation. In other words, the steepness of the curve is directly
related to the degree of consistency in the sample resuhs.
9.2 GUIDANCE FOR DIRECT DISCHARGES
Because only one direct discharger was identified in the linen supply and
industrial laundry subcategories, the Agency did not develop data for the achievable
performance of treatment technologies for direct dischargers. However, the
Agency feels that the applicable technology would be DAF followed by biological
treatment for the further reduction of conventional pollutants. Trickling filters or
stabilization ponds (facultative lagoons) would be effective biological treatment
options.
Pollutants to be controlled would include those selected for pretreatment
(chromium, lead, copper and zinc) and the major conventional pollutants found in
laundry wastes: TSS, BOD and oil and grease. Conventional pollutant
concentrations presented in Table 1-1 reflect the discharge limitations currently
imposed on the one known direct discharger. The Agency has determined that these
concentrations are achievable using the technologies of DAF and biological
treatment.
134
-------
REFERENCES
1. Draft Preliminary Qualitative Economic Assessment of Effluent Limitations
in the Laundries Industry. Contract 68-01-4618, U.S. Environmental
Protection Agency, Washington, D.C. (Preliminary document submitted to
EPA by Energy and Environmental Analysis, Inc., September 8, 1977.) 25 pp.
2. Economic Effects of Water Pollution Control on the Laundry Industry, Phase
II. Contract 68-01-2*12, U.S. Environmental Protection Agency,
Washington, D.C. (Preliminary document submitted to EPA by Colin A.
Houston 3e Associates, Inc., April 15, 1974.) 207 pp.
3. Preliminary Quantitative Economic Assessment of Effluent Limitations in the
Laundries Industry. Contract 68-01-4618, U.S. Environmental Protection
Agency, Washington, D,C. (Preliminary document submitted to EPA by
Energy and Environmental Analysis, Inc., January 10, 1978.) 72 pp.
4. Johnson, K.C. Laundering. In: Kirk-Othmer Encyclopedia of Chemical
Technology, Second Edition, Vol. 12. John Wiley dc Sons, Inc., New York, New
York, 1967. pp. 197-207.
5. Osos, G. R. Successful Steam Tunnel Finishing. Linen Supply News, 61(2):90-
92, 1977.
6. Wile, J. L. Latest Development Rundown on Washroom Machinery 4
Supplies. Institutional Laundry, 16(8):20-22, 1972.
7. Martin, A. R., F. Loibl, G. E. Leonhardt, and H. E. Reeves. Drycleaning. In:
Kirk-Othmer Encyclopedia of Chemical Technology, Second Edition, Vol. 7.
John Wiley & Sons, Inc., New York, New York, 1965. pp. 307-326.
8. Development Document for Effluent Limitations Guidelines and New Source
Performance Standards for the Auto and Other Laundries Category, Part I.
U.S. Environmental Protection Agency, Washington, D.C. (EPA draft
document, January 1977.)
9. Powder Power Puts Profit in Solvent Recovery. Laundry Cleaning World,
1(2):18-19, 1973.
10. Bee, B. Increasing Solvent Mileage. Coinamatic Age, 34(4):38, 1976.
11. McCoy, J.R. Solvent Filtration with Cartridge Type Filters. Coinamatic
Age, 34(4):28-30, 1976.
12. Hasenclever, K.D. The Basis of Effective Drycleaning Distillation. Power
Laundry & Cleaning News, pp. 15-17, June 1977.
13. An "update" on workwear processing in the USA. Power Laundry and
Cleaning News, November 11, 1977.
135
-------
References - continued
14. KJep\>r, M. H., R. L. Goldsmith, and A. Z. Gollen. Demonstration of
Ultrafiitration and Carbon Adsorption for Treatment of Industrial Laundering
Wastewater. EPA-600/2-78-177, U.S. Environmental Protection Agency,
Cincinnati, Ohio, August 1978. 121 pp.
15. Rosenthal, B. L. et al. Industrial Laundry Waste Water Treatment Study.
Project #48, Massachusetts Health Research Institute, Inc., Boston,
Massachusetts, April 1964. 93 pp.
16. Cogely, D. R. and B. A. Weschler. Occurrence and Treatability of Priority
Pollutants in Industrial Laundry Wastewaters. Draft Final Report. Grant No.
5-804367-01, U.S. Environmental Protection Agency, Cincinnati, Ohio.
January 1978. 110pp.
17. Douglas, G. Modular Wastewater Treatment System Demonstration for the
Textile Maintenance Industry. EPA-660/2-73-037, U.S. Environmental
Protection Agency, Washington, D.C., January 1974. 342 pp.
18. Van Hess, W., E. W. Lard, and Dr. R. Me Minn. A Continuous Shipboard
Laundry Wastewater Treatment and Recycling System. David W. Taylor
Naval Ship Research and Development Center, Annapolis, Maryland. 19 pp.
19. Guarino, V. J.f and R. A. Bambenek. Development and Testing of a
Wastewater Recycler and Heater. EPA-600/2-76-289. U.S. Environmental
Protection Agency, Cincinnati, Ohio. December 1976. 106 pp.
20. Lent, D. 5. Treatment of Power Laundry Wastewater Utilizing Powdered
Activated Carbon and Cationic Polyelectrolytes. In: Proceedings of the 30th
Industrial Waste Conference, Purdue University, Lafayette, Indiana, May
1975. Ann Arbor Science Publishers, Inc., Ann Arbor, Michigan. January
1976.
21. Galonion, G. E., and D. B. Aulenback. Phosphate Removal from Laundry
Wastewater. Journal of the Water Pollution Control Federation, 45(8):170S-
1717. August 1973.
22. Aulenback, D. D., P. C. Town, and M. Chilson. Treatment of Laundromat
Wastes. EPA-R2-73-I08, U.S. Environmental Protection Agency,
Washington, D.C., February 1973. 65 pp.
23. Wastewater Engineering, Collection, Treatment, and Disposal. Metcalf and
Eddy, Inc., McGraw-Hill Book Company, New York, New York, 1972. 782 pp.
24. Patterson, I. W. Wastewater Treatment Technology. Ann Arbor Science
Publishers, Inc., Ann Arbor, Michigan, 1975. pp 175-189.
25. Process Design Manual for Upgrading Existing Wastewater Treatment Plants.
Technology Transfer, U.S. Environmental Protection Agency, Cincinnati,
Ohio, October 1974.
26. O'Melia, C.R. Coagulation and Flocculation. In: Physicochemical Processes
for Water Quality Control, Chapter 2, W. J. Webster, Jr., ed. Wiley-
Interscience, New York, New York, 1972. pp. 61-91.
136
-------
References - continued
27. Process Design Manual for Suspended Solids Removal -Technology Transfer,
U.S. Environmental Protection Agency, Cincinnati, Ohio, January 1975. pp.
4-1, 4-2.
28. Wastewater Treatment Plant Design, Manual of Practice No. 8. Water
Pollution Control Federation, Washington, D.C., 1977. 560 pp.
29. Pinto, S.D., Ultrafiltration for Dewatering of Waste Emulsified Oils, In:
Proceedings, First International Conference, Lubrication Challenges in
Metalworking and Processing, IIT Research Institute, Chicago, Illinois, 1973.
4pp.
30. Ramirez, E. R. Electrocoagulation Clarified Food Wastewater. Deeds and
Data, Water Pollution Control Federation, April 1975. 3 pp.
31. Minturn, R. £., J. S. Johnson, Jr., W. M. Schofield, and D. K. Todd.
Hyperfiltration of Laundry Wastes. Water Research, 8(ll):921-926, 1974.
32. Grives, R. B., and J. L. Bewley. Treating Laundry Wastes by Foam
Separation. Journal of the Water Pollution Control Federation, 45(3):470-
479, 1973.
33. McCarthy, J. J., and R. H. Chyvek. Evaluation of a Vapor Compression
Distillation Unit for Laundry Wastewater Reuse. Technical Report 7711, U.S.
Army Medical Research and Development Command, Washington, D.C.,
August 1977. 45 pp.
34. Baker, R. J. Degan, and R. Weston. Pilot Plant Studies of the Biological
Treatment of Petroleum Refinery Wastes. In: Proceedings of the
Pennsylvania Sewage Wastes Association, August 1952.
35. Coe, R. Bench-Scale Biological Oxidation of Refinery Wastes with Activated
Sludge. Sewage Industrial Wastes, 24(6):1952.
36. Tabakin, R. B., R. Trattner, and P. N. Chevemisinoff. Oil/Water Separation
Technology: The Option Available, Part 2. Water and Sewage Works,
125(8):72-75, 1978.
37. Process Design Manual for Sludge Treatment and Disposal. Technology
Transfer, U.S. Environmental Protection Agency, Cincinnati, Ohio, October
1974. pp. 7-1/7-94.
38. Federal Register. 43(243}:58956-58957, December 18, 1978.
39. Meredith, D. C., K. W. Wong, R. W. Woodhead, and R. H. Wortman. Design
and Planning of Engineering Systems. Prentice-Hall, Inc., Englewood Cliffs,
New Jersey, 1973. 393 pp.
40. Current Prices of Chemicals and Related Materials. Chemical Marketing
Reporter, 215(3):40-49.
41. Parker, R. S., Jr. Assessment of Dissolved Air Flotation Sludge Management
Options in Industrial Laundry Wastewater Treatment. (Draft) Contract No.
117
-------
References - continued
S-804367-Q1. U.S. Environmental Protection Agency, Cincinnati, Ohio,
October 197S. 48 pp.
42. Van Note, R. H., P. V. Hebert, R. M. PateJ, C. Chupek, and L. Feldman. A
Guide of the Selection oi Cost-Effective Wastewater Treatment Systems.
EPA-430/9-75-002, U.S. Environmental Protection Agency, Washington,
D.C., July 1975.
43. Peters, M.S. and K. D. Timmerhaus. Plant Design and Economics for
Chemical Engineers. McGraw-Hill Book Company, New York, New York,
1968, 850pp.
44. Pound, C. £., R. W. Cites, and 0. A. Griff es. Cost of Wastewater Treatment
by Land Application. EPA-430/9-75-003, U.S. Environmental Protection
Agency, Washington, D.C., June 1975. 156 pp.
45. Letter from Institute of Industrial Launderers to Environmental Protection
Agency; October 31, 1979.
46. Nemerow, N. L. Liquid Waste of Industry, Theories, Practices, and
Treatment. Addison-Westey Publishing Company, Reading, Massachusetts,
1971. 584pp.
47. Federal Guidelines, State and Local Pretreatment Programs. Volume 1.
EPA-430/9-76-Q17a, U.S. Environmental Protection Agency, Washington,
D.C., January 1977. 196 pp.
48. Beychok, M. R,, Aqueous Wastes from Petroleum and Petrochemical Plants,
John Wiley & Sons, N.Y., 1967.
49. NIH-EPA Chemical Information System, The Oil and Hazardous Materials -
Technical Assistance Data System (OHMTADS), May 21, 1979.
50. "Anaerobic Processes - Literature Review", Ghosh, S., Journal of the Water
Pollution Control Federation, Vol. 44, No. 6, June 1972. p. 948.
51. "Inhibition of Anaerobic Digestion of Sewage Sludge by Chlorinated
Hydrocarbons," Swan wick, J. D. and Margaret FouJkes, Water Pollution
Control. Vol. 70, 1971. p. 58.
52. "The Effect of Chloroform in Sewage on the Production of Gas from
Laboratory Digesters," Stickley, D. P., Water Pollution Control^ Vol. 69,
1970. p. 585.
S3. "Combined Treatment of Chemical Wastes and Domestic Sewage in
Germany", Bischofsberger, Wolfgang, Proceedings of the 24th Industrial
Waste Conference (1969). Purdue University, p. 920.
54. Ryer, F. V. Soap. In: Kirk-Othmer Encyclopedia of Chemical Technology,
Second Edition, Vol. 18. John WUey & Sons, Inc., New York, New York, 1969.
pp. 415-432.
138
-------
References - continued
55. Schwartz, A. M. Detergency. In: Kirk-Othmer Encyclopedia of Chemical
Technology, Second Edition, Vol. 6. John Wiley & Sons, Inc., New York, New
York, 1965. pp. 853-895.
56. Zweidler, R., H. Hausermann, and 3. R. Geigy. Brighteners, Optical. In:
Kirk-Othmer Encyclopedia of Chemical Technology, Second Edition, Vol. 3.
John Wiley & Sons, Inc., New York, New York, 196f. pp. 737-750.
57. Current Prices of Chemicals and Related Materials. Chemical Marketing
Reporter, 215(3):*
-------
APPENDIX A
LAUNDRY WASTEWATER TREATABIUTY DATA
In the following tables, A-l through A-20, treatability data for the various
systems described in Section 7 are given:
o The data in Tables A-l through A-6 are given for industrial laundries
utilizing calcium chloride coagulation and OAF.
o The data in Tables A-7 through A-ll are given for linen supply and
commercial laundries utilizing polyelectrolyte coagulation, DAP,
filtration and wastewater recycle.
o The data in Tables A-12 and A-13 are given for an industrial laundry
utilizing alum coagulation, DAF, filtration, and wastewater recycle.
o The data in Tables A-14 and A-l5 are given for an industrial laundry
utilizing ferrous sulfate coagulation and DAF.
o The data in Tables A-l6 and A-17 are given for a linen laundry utilizing
ferric sulfate coagulation and DAF.
o The data in Tables A-IS and A-19 are given for a service laundry which is
a direct discharger. The treatment system utilizes alum coagulation,
clarification, carbon adsorption, filtration and
chlorination/dechlorination.
o The data in Table A-20 is given for an industrial laundry utilizing calcium
chloride coagulation and DAF.
A-l
-------
TABLE 'A-l. PLANT A
Concentration, mg/1
City
Pollutant Water
COO
TOC
TSS
Oil and pease
Phosphorus
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Nickei
Selenium
Thallium
Zinc
Cyanide
Phenol (total)
Benzene
Carson tetrachlaride
1,1,1-Trichloroethane
2,4,4-TrictUorophefwl
Chloratorm 0.0008
Dichiorebenzenes
2,4-Dimethyiphenol
Ethylbenzene
Methylene chloride 0.007
Diehlar obromomethane 0 . 00 3
Naphthalene
Pentachlorophenol
Phenol m
6u(2-«thylhexyl)phthalate 0.012
Butyl benzyl phthalate
Qi-n-Butyl phthaiate 0.0007
Di-n-Octyl phthaiate - »
Anthracene/phenanthrene - '
Tetncnleroethylene 0.010
Toluene 0.010
T_:.d.i..««^vhwl_Mi _
Influent
6,400
1,700
390
131
869
313
3%
11.6
0.094
0.010
0.11
0.«8
1.5
4.S
0.33
JL 0.001
< O.OhO
3.7
0.037
0.78
0.003
0.002
0.018
.
0.0007
l.l
0.46
0.025
0.002
-
».s
-
0.098
1.2
0.31
0.092
0.13
0.38
0.32
0.36
0.004
Effluent
3,200
690
98
1*4
1*9
123
133
1.7
< 0.010
0.002
< 0.002
0.27
0.30
0.13
0.23
0.002
0.030
0.23
0.034
0.76
0.003
0.001
O.OU
0.003
0.0008
0.26
-
0.04ft
0.002
•
0.84
0.017
0.042
0.22
0.019
0.033
0.066
0.33
0.38
0.006
A-2
-------
TABLE A-:. PLAOT B
Concentration mg/1
Pollutant
pH
COD
T5S
Oil and grease
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Thallium
Zinc
Phenol (total)
Chloroform
Ethylbenzene
Methylene chloride
Dichlorobromomethane
Isophorane
Naphthalene
N-Nitrosodiphenylamine
Phenol
Bis(2-ethyihexyi)phthalate
Di-n- Butyl phthaiate
Diethyl phthaiate
Tetrachloroethylene
Toluene
Trichloroethylene
City
Water
7.0
<0.020
<0.010
0.005
<0.050
<0.025
<0.010
< 0.0002
<0.050
0.002
0.055
0.030
-
0.020
0.015
-
-
-
-
1.2
0.005
0.005
0.007
-
-
Influent
11.6
3,800
700
440
0.041
0.012
0.017
0.27
1.6
9.*
0.002
0.15
-------
TABLE R-3. PLANT C
Concentration, mg/1
Pollutant
pH
COD
T5S
Oil and grease
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Silver
Zinc
Phenol (total)
Chloroform
Ethylbenzene
Methyiene chloride
Dichlorobromomethane
Naphthalene
Phenol
Bis{2-ethylhexyl)phthalate
Tetrachloroethyiene
Toluene
City
water
7.3
<0.020
0.011
<0.002
<0.050
<0.025
<0.010
< 0.0002
<0.050
-------
TABLE A-4. PLANT D
Concentration, mg/1
Pollutant
pH
BOD.
CODJ
TOC
T55
Oil and grease
Antimony
Cadmium
Chromium
Copper
Lead
Nickel
Zinc
Cyanide
Benzene
Ethylbenzene
Bis(2-ethylhexyl)phtnalate
Tetrachloroethylene
Toluene
City
water
7.7
<2
<5
2
<5
<5
<0.10
<0.00l
0.010
0.026
< 0.020
<0.01
0.094
-
0.040
-
-
-
0.010
Influent
11.7
2,400
7,100
1,800
940
1,600
0.16
0.070
0.98
1.7
5.4
0.08
2.7
0.28
0.13
17.5
2.6
0.030
2.6
Effluent
9.3
1,000
2,000
500
100
230
0.31
0.003
0.57
0.15
0.11
-
-
0.29
0.20
-
1.0
0.98
0.90
A-5
-------
TABLE A-5. PLANT £
Pollutant
BOD,
coir
TOC
TSS
Oil and grease
Phosphorus
Antimony
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Silver
Zinc
Cyanide
Phenol (total)
City
water
<20
_
-
0.005
<0.005
0.050
<0.020
<0.0001
<0.005
<0.001
<0.060
0.050
Contration mg/1
Influent
1,700
4,900
460
900
230
13
0.12
0.011
0.060
0.30
1.0
3.0
<0.003
"0.080
0.008
2.0
0.24
0.10
Effluent
540
1,100
270
18
84
23
0.029
-
cO.002
0.10
0.20
0.070
0.002
<0.005
0.019
0.060
0.53
0.32
A-6
-------
TABLE A-6. PLANT F
(DATA OBTAINED FROM-LINEN SUPPLY ASSOCIATION OF AMERICA)
Pollutant
BOD,
TSS
Oil and grease
TOG
pll
Cadmium
Chromium
Lead
Meicurf
Nickel
Zliic
Influent
460
420
174
70
II
0.03
0.13
2.6
<0.0002
<0.02
1.0
Day 1
effluent
4)0
10
9)
128
6.3
O.I
0.11
<0.03
<0.0002
<0.02
0.10
Day
Inllurnl
2,030
830
422
223
11.4
0.0)
I.I
7.9
< 0.0002
<0.02
3.1
2
Effluent
610
240
107
167
7.3
O.I*
0.3
0.3
<0.0002
<0.02
0.2
Concentration,
Oar 1
Influent
73)
920
212
222
11.6
0.03
0.99
3.)
<0.0002
<0.02
1.9
mg/l
Eflluent
160
100
10
164
7.2
0.09
0.37
<0.03
<0.0002
<0.02
0.2S
ttaf
Influent
360
too
366
43.3
II.)
<0.002
0.336
4.9
<0.0002
<0.02
1.1
4
Ellluent
130
60
4)
9)
7.0
0.0)
0.17
0.2
<0.0002
<0.02
0.2
DDT
Influent
3(0
910
1.190
1)4
11,4
O.I)
0.64
6.)
<0.0002
<0.02
3.)
,
Effluent
2<0
2)0
9
224
6.9
'0.002
0.29
0.7
-------
TABLE R-7. PLANT G
Concentration, mg/l
Pollutant
pH
BOO*
COD
TOC
TSS
Oil and create
Choiphorut
Antimony
Arunlc
Cadmium
Chromium
Copper
Mercury
Nickel
Selenium
Silver
Ztnc
Cyanide
Phenol (tollO
Benxene
Qilorolorm
2-Chloranhenol
2,4-Dlchlcirophenol
2,4-OltMlhrlptKMl
Elhylbehiene
Methytanc chlorMe
Naphthalene
2-Nllropheml
Phenol
UI-rt-Butyl phthalale
Methyl etithalate
Anthracene jpie nanthrene
Tetrachloroelhylene
Toluene
TrkhloroethyleM
Ifcptachlor
City
Wale*
;.)
-------
TABLE A-8. PLANT H
Concentration, mg/1
Pollutant
pH
BOD,
COD^
T5S
Oil and grease
Cadmium
Chromium
Copper
Lead
Nickel
Zinc
Phenol (total)
Chloroform
Methylene chloride
Dichlorobromomethane
Phenol
Bis(2-ethylhexyl)phthaiate
Toluene
City
water
7.1
<6
2
<1
36
0.0003
<0.010
0.005
<0.003
<0.010
0.16
<0.001
0.006
0.007
0.008
-
-
0.007
Influent
10.9
850
2, WO
250
WO
0.010
0.060
0.15
0.11
0.025
0.43
0.13
0.020
-
-
0.030
9.0
0.025
Effluent
11.0
900
2,600
280
220
0.007
0.20
0.19
0.21
0.048
0.56
0.16
0.023
-
-
0.048
0.80
0.014
A-9
-------
TABLE A-9. PLANT Z
Concentration, mg/1
Pollutant
pH
BOD,
COD^
Oil and grease
Antimony
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Zinc
Phenol (total)
Chloroform
Methylene chloride
Bis(2-ethylhexyl)phthalate
Toluene
City
water
7.4
<5
96
30
<0.002
0.0002
0.025
0.030
0.001
O.OOS
0.010
0.010
<0.001
0.020
-
0.020
0.017
Influent
9.9
780
1,700
400
0.014
0.003
0.038
0.095
0.038
<0.0005
<0.010
0.17
0.26
0.18
0.035
-
0.080
Effluent
9.6
820
490
no
0.010
0.003
0.015
0.070
0.047
<0.0005
<0.010
0.065
0.055
0.022
0.030
-
0.040
A-10
-------
TABLE A-10. PLANT I
(DATA OBTAINED FROM LINEN SUPPLY ASSOCIATION OF AMERICA)
Day 1
Pollutant
BOOj
TSS
Oil and grease
Cadmium
Chromium
Lead
Nickel
pll
Merctrr
Zinc
TOC
kiiluent
721
390
420
<0.002
<0.02
-------
TABLE
City
Pollutant water
Oil and grease 0
BOD. i
3
COD <10
TOC 2.5
TSS <1
Phosphorus 0 .OS
Cyanide (total) <0.002
Phenol (total) 0.005
Antimony
Cadmium < 0.002
Chromium 0.014
Copper 0.021
L«ad <0.022
Nickel <0.036
Silver
-------
TABLE A-12. PLANT K
u>
Concentration, tng/l
Day 1
Pollutant
oH
r *
Oil and pease
BOD.
COO
roc
TSS
Phosphorui
Cyanide (lota))
Phenol (total)
Antimony
Arienlc
Cadmium
Chromium
CoiiAef
^" IT^*
Lead
Mercury
Nickel
Selenium
Stiver
Zinc
Acroleln
Caibun lelraddorlde
CM or obelize ne
1,1 ,1-Trlchloroe thane
Z-CMoroiuphlhalene
Oilorolorm
Elhylbenzen*
rfcornodlcM or oine thane
Trlchlorolluoromelliane
Naphllialene
phenol
Bls(2-elhylheiiyl)phlhalate
Dulyl benzyl phthalaie
ni-n-nulylphlhalile
nl-n-Octyl phllialate
Anlhracene/lilKnanlhrene
TetracMoroeth|rlene
Toluene
City
water
-------
TABLE A-13. PLANT K
(DATA OBTAINED FROM -EQUIPMENT" MANUFACTURER)
Concentration, ms/1
BOD
COD
Oil and grease
pH
Chlorine as Cl
Total dissolved solids
Total suspended solids
Volatile dissolved solids
Volatile suspended solids
Mercury
Cadmium
Lead
Sulfate, as 5O<»
Arsenic
Cyanide
Phenol
Total coliform, per 100 ml
Color, APHA color units
Carbonate, as €03
Silicate, as SiO^
Calcium
Iron
Aluminum
Nickel
Zinc
Chromium
Total organic carbon
Copper
Antimony
Alkalinity as CaCO3
Ammonia nitrogen, as N
Nitrate nitrogen, as N
Sodium
Carbon dioxide, as CO2
Influent
180
1,290
175
10.64
<0.01
3,558
51
712
20
0.0010
0.02
0.10
1,590
<0.05
<0.01
0.0
-------
TABLE A-14. PLANT L
OncmlitlM. M|A
air
ran
Cllhlrnl
tlllwl
MbMt
Illluml
kflwnl
1.1
roc
ru
pii.~ii.o-
la i
l.roo
».io*
I.1M
}!•
110
ir
Cj.
Ckranlwi
fnr
Wnci>f
Hckil
W»n
IbK
rimobniiH*
l.l.l- fllcMotMll
1.1-McMgfMd
<».00t
<• ODI
<0 004
•O.OW
i.ooal
<• M>
<0 Nl
fO •»
• .It
a.aoM
* n
OOll
• •H
o ai*
ou
10
ll.t
on)
• oto
i« OOt
"la
IIB
II
• ai
• 041
» *
• Oil
I.OIl
a. OH
ii>»ui>
-*-f»,t pMh.Ul.
• lit
• Nf
.Ml
10.1
I.4H
100
«ao
if
•.Ml
•.II
•.II
0.011
O.OM
IT
1.0
O.MI
•.M
•ir
•.DM
•.Mi
•.MM
I.D
HO
*M
MO
H
U
O.It
«» 010
1.1
• •II
• •II
«0 Ml
•0 001
••«*> R
<• ooi
o.n>
a.on
I^B.OIO
• DM
• .Oil
•••II
• II
•.II
• .OH
• 0)1
<0 IW
t an
•.on
R Rejected as outlier for calculations in Section 9.
-------
TABLE A-15. PLANT L
(DATA OBTAINED PROM LINEN SUPPLY ASSOCIATION OP AMERICA)
Concentration. mn/I
n»« 1 111* 2
Pollutant
BOD)
TSS
Oil and greate
Lead
Mercury
Nickel
Cadmium
ptl
Zinc
Chromium
TOC
Influent
7)7
»«
W
|)
<0.0002
<0.02
0.07
IO.C
2.1
O.M
1*7
Effluent
1)
100
12
0.)
<0.0002
<0.02
-------
TABLE A-16. PLANT M
Concentration, mg/l
Pollutant
pH
BOD*
COD
TOC
TSS
Oil and grease
Phosphorus.
Antimony
Arsenic
Chromium
Capper
Lead
Mercury
Silver
Zinc
Clly
Water
7.0
0. 001
0.006
~0.60
Cltliwnl
J.J
210
420
ISO
56
24
0.3)
0.00)
0.008
<0.00)
0.30
(0.020
0.001
-------
TABLE A-17. PLANT H
OS
PolhilanI
BOO,
TSS
Oil and grease
tead
Mercurf
Nickel
Cadmium
Zinc
Ovomluni
TOC
PH
Day
hllucnl
1,790
•90
389
0.6
<0.0001
O.II
303
7.0
Day 2
hllucnl
2,700
«20
111
0.3
< 0.0002
-------
TABLE A-18. PLflNT N
TOC
TSS
BODS
Cyanide
Phenol
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Nickel
Zinc
Concentration, mg/1
Pollutant
City
water
Raw
wastewater
darifier
effluent
Filter
effluent
0.020
0.005
0.005*
<0.001
<0.002
0.60
A-19
-------
TABLE A-19. PLANT N
Concentration, mg/1
Pollutant
Oil and grease
BOD,
j
COD
TOC
TSS
Phosphorus
Cyanide (total)
Phenol (total) '
Cadmium
Chromium
Copper
Lead
Nickel
Silver
Zinc
Phenol
1 , 1 ,2,2-Tetrachloroethane
Chloroform
Methylene chloride
Dichlorobromomethane
Cnlorodibromometnane
Pentachlorophenol
Phenol
Bis(2-ethylhexyi) phthalate
Butyl benzyl phthalate
DL-n-Butyl phthalate
Di-n-Octyi phthalate
Oiethyl phthalate
Tetrachloroethylene
Toluene
Trichloroethylene
Raw
waste water
17
7
20
16
157
137
215
143
240
63
40
7.0
< 0.002
0.038
0.051
0.039
0.138
0.071
0.055
O.OL4
0.609
0.0018
-
-
-
•
0.0006
-
_
-
0.002
0.005
0.0005
Clariiier
effluent
7
1
5
3
60
45
89
34
125
40
46
1.6
< 0.002
0.028
0.012
0.034
0.03L
0.066
0.050
0.011
0.244
0.002
-
0.07
0.038
-
-
-
0.002
0.067
0.36
0.007
0.005
0.10
0.003
0.012
Carbon
effluent
9
12
2
50
30
45
17
136
38
78
2.0
< 0.002
0.029
0.015
0.036
0.042
0.065
< 0.036
0.007
0.212
O.OOL
-
0.018
0.003
-
-
0.003
0.001
0.023
0.017
0.005
0.004
0.003
0.032
0.004
0.005
Filter
effluent
3
0
0
0
41
11
24
15
59
21
37
0.9
< 0.002
0.013
0.014
0.025
0.032
0,031
0.037
0.007
0.244
0.0007
0.095
-
0.010
-
-
-
0.016
0.004
0.003
0.002
0.031
0.006
0.003
A-20
-------
TABLE A-20. PLANT Z
(RESULTS IN mq/1)
KJ
OaV
1- tnlluenl
cCllucnt
2- Influent
diluent
)- Influent
ellluenl
»- InHiieirf
diluent
)- Inlluent
ellluenl
6- Inlluent
diluent
7- Inlluent
ellluent
•- Influent
el fluent
9- Inlluenl
effluent
10-lnlkicnl
ellluent
II- Influent
ellluent
12- Inlluenl
ellluenl
II- Influent
ellluent
14- Inlluent
effluent
19-liifl.ienl
ellluent
16-lnEluenl
ellluent
17- Inlluent
ellluent
IS- Inlluent
ellluenl
19-lnfluenl
eltluent
20- Inlluenl
ellluent
21 -Influent
ellluent
22-lnfluetil
ellluenl
21-lnfhient
ellluenl
Suspended
pll Solids
11.7 1100
9.) R DOQ R
II. T 9)0
10.
II.
10.
II.
r.
II.
10.
II.
10.
II.
10.
II.
9.
II.
II.
II.
1.
R 1070 R
1076
R mo R
9*0
140
jao
240
90
36
1300
BOO
860
270
11)0
3)0
1)00
320
9.1 tint
a.
li.
i.
•
•j ^
li'
u.
li.
8.
10.
10.
II.
s.
u.
ga
II.
7.
II.
II.
II.
II.
II.
370
18*0
7*0
1310
460
9'iO
710
900
110
960
700
1640
)90
1100
790
II tD
240
710
)2)
970
710
780
2.} R 440
11.1 940
9.7 R 170 R
BOD
1270
1144 R
1)40
1110 R
1)40
1479 R
1068
tit
mi
641
1129
496
17(1
992
1098
7)9
1980
670
12)0
820
700
397
1100
1080
170)
809
976
f>7l
960
7)0
2418
10))
2410
976
1MO
12)0
916
702
1144
814
«7SO
1910
30)0 R
710
270
310
140
570
290
490
260
1032
Ml
690
)n
«I3
217
>80
)60
1930
170
600
250
7M
220
1)30
)40
770
290 R
Copper
1.70
I.30R
1.60
1.10 R
1.67
1.10 R
1.40
0.50
1.30
0.63
HO
0.))
1.60
1.10
1.66
0.77
l.)l
1.00
2.00
1.7)
1.90
0.6)
2.00
I.W
1.70
0.66
1.60
0.8)
l.)l
0.9&
1.44
0.92
1.79
1.72
1.43
0.88
1.52
0.79
1.42
0.80
1.42
0.70
1.09
0.86
1.7)
1.30 R
Chromium
0.26
O.I4R
0.22
0.19 R
0.07
0.0) R
0.0*
0.02
0.23
0.10
0.19
0.0*
0.2)
0.14
0.20
0.14
0.2)
0.17
0.22
O.I)
0.29
0.10
0.30
0.70
0.3)
0.19
0.30
O.I)
0.23
0.16
0.19
0.09
0.21
0.12
0.27
0.18
0.22
0.13
0.21
0.08
0.19
0.08
0.17
0.09
0.31
O.I4H
Lead
4.70
3.01 R
4.90
2.80 R
4. 55
3.80 R
3.70
0.18
4.20
0.40
3.30
0.13
1.40
1.33
3.80
0.)}
2.70
0.13
3.90
1.20
4.00
0.20
4.20
1.60
3.90
0.30
4.00
0.4)
3.61
1.26
3.4B
2.06
3.48
1.70
4.13
2.48
4.37
1.2)
3.44
0.12
4.70
1.48
4.0)
I.4S
4.39
3.92 R
Zinc
4.10
2.60 R
1.20
2.30 R
4.00
3.40 R
3.30
0.13
4.00
0.50
2.90
0.12
3.40
1.10
3.20-
0.10
2.33
0.3)
3.00
0.76
2.63
0.09
3.30
1.06
3.60
0.12
3.30
0.40
3.11
I.OO-
3.17
1.78
3.25
l.)l
3.3)
2.1)
3.42
0.81
3.93
0.6S
3.36
I.OB
3.13
0.98
3.22
3.I4R
Nickel
0.13
0.14 R
0.18
O.I) R
0.14
0.14 R
0.12
<0.0i
O.I)
0.09
O.I)
<0.0)
0.19
0.06
0.12
0.08
0.10
0.06
0.10
0.09
0.13
<0.0)
0.14
0.12
0.14
0.08
0.10
0.06
O.I)
0.13
O.lf
O.I)
0.17
0.12
0.16
0.16
0.13
0.10
0.16
0.10
0.13
0.07
0.10
0.16
0.20
o.i) R
Antimony
0.08)
0.13 R
0.072
0.17 R
0.08K
0.10 R
0.091
0.110
0.071
0.14
0.066
0.091
0.072
0.074
0.060
0.14
0.069
0.091
0.094
0.084
0.078
0.074
0.091
0.04)
0.091
0.12
0.11
0.0)8
0.076
O.OfiO
0.091
0.094
0.076
0.091
0.14
0.12
0.10
0.063
0.11
0.0))
0.11
0.91 R
0.078
0.12
0.091
0.0 CO
R Rejected as outlier for calculations in Section 9.
-------
APPENDIX B
SURVEY OF THE AVAILABILITY OF SPACE FOR
WASTEWATER TREATMENT AT INDUSTRIAL LAUNDRIES
A study to determine the availability of space for the installation of
equipment for treatment of industrial laundering wastewater was conducted by the
Jacobs Environmental Division of Jacobs Engineering Group Inc. under EPA Mission
Contract No. 68-01-5767. The study consisted of a survey of <*5 randomly selected
sites located in major metropolitan areas of the United States. The sites were
visited to gather information on plant size, plant operations and wastewater volumes
and to assess the availability of space for wastewater treatment. Where space was
not readily available, an estimate of the cost of preparing space or acquiring new
space was made.
1.0 PURPOSE
The purpose of this study was to provide an estimate of the percentage of
industrial launderers with available space, interior or exterior, for the installation of
treatment systems and to provide a breakdown of costs expected to be incurred by
facilities lacking readily available space.
A worst-case cost estimate, previously prepared, indicated that costs for
treatment of laundry wastes could be prohibitive if space for equipment was not
available. Since input from industry sources indicated that space was generally not
available, it was evident that a site survey of the industry was necessary.
2.0 SURVEY APPROACH
2.1 Target Population: Linen Supply and Industrial Launderers
The original design of the survey was to encompass sampling from Industrial
Launderers (SIC 7218) and Linen Supply (SIC 7213). In order to ascertain the
composition and extent of these two segments of the laundry industry, reference
was made to two sources; e.g., County Business Patterns and the EPA Draft
Development Document for Autos and Other Laundries. Table 2-1 presents the total
number of U.S. establishments from these sources.
B-l
-------
TABLE 2-1. REFERENCED NUMBER OF ESTABLISHMENTS IN U.S.
INDUSTRIAL LAUNDERERS (SIC 7218)
LINEN SUPPLY (SIC 7213)
Primary SIC
. „————.- Reference
7213 7218
U67 913 County Business Patterns, 1976
1300 1000 EPA Draft Development Document,
1978
B-2
-------
It was recognized during the initial planning of the survey
that the most severe economic impact due to lack of space for
treatment systems would more likely occur in metropolitan or
land-congested areas. Therefore, a decision was made to initiate
the survey in concentrated metropolitan centers. It was also
felt that industrial launderers and linen suppliers would be
found to be located near these centers approximately to the
degree that population is concentrated.
The Standard Metropolitan Statistical Area (SMSA) was chosen
as the geographic unit on which to base the sample design., It
has been estimated that at least 75 percent of the U.S.
population is located within SMSAs. For a given metropolitan
area, an SMSA may include a more representative, cross section
than units having political boundaries such as cities or
counties.
Since a major component of survey costs for this study was
travel to the SMSA rather than travel within a metropolitan area,
the five largest SMSAs which include the cities of New York, Los
Angeles, Philadelphia, Chicago, and Detroit were chosen for
survey. This provided sampling of laundries in areas of heaviest
population concentration while covering the largest fraction of
the laundry industry for a-given number of trips.
Since it was necessary to formulate a survey design and plan
which would encompass all industrial .launderers and linen supply
including those not having SIC 7218 or 7213 a.s primary
classifications, the sampling frame was based on information from
two sources: telephone directory yellow pages and Dun and
Bradstreet Market Identifiers data base. Both sources were
required because little overlap was found to exist between the
two sources. Table 2-2 shows the state of knowledge concerning
establishments in these two industries.
It can be seen from the above table that one industrial
laundry or linen supply in seven (14.2%) is located in one of the
five largest SMSAs.
2.2 Target Population: Industrial Laundries
During the course of the study, emphasis was directed toward
industrial laundering as the target population since this
industry generates larger pollutant loads and is more likely to
be regulated. Since many linen supply establishments also have
industrial laundering as a secondary or other SIC operation,
however, linen supplies were not excluded from the list of
potential survey sites.
B-3
-------
TABLE 2-2. NUMBER OF ESTABLISHMENTS* IN FIVE LARGEST STANDARD
METROPOLITAN STATISTICAL AREAS
INDUSTRIAL LAUNDERERS (SIC 7218)
LINEN SUPPLY (SIC 7213)
Standard
Metropolitan Dun&Bradstreet
Statistical Market
Area identifiers
New York
Los Angeles
Philadelphia
Chicago
Detroit
Subtotal
Remainder of U.S.
In SMS A
Outside SMS A
National Total
118
75
45
60
53
351
1414
705
2470
Telephone Both D&B Net
Directory and Composite
Yellow Yellow Sampling
Pages Pages Frame
117 72 163
88 26 137
79 22 102
69 29 100
64 27 90
417 176 592
* Establishments which declare SIC 7218 or SIC 7213 as primary
through sixth Standard Industrial Classification to D&B
Marketing Services.
B-4
-------
Because the target pope Is-!•:•: c-r.sizrtsc cf both telephone
directory listings and Dun & r-r^s-rsst data with little overlap,
,md since there was no •* ? to classify telephone listings,
estimates of the number of industrial laundry establishments were
made by using the fraction previously indicated for Dun &
Bradstreet. Table 2-3 shows these estimates.
It can be seen that from this estimate approximately 18
percent of all U.S. industrial launderers occur in one of the
five largest SMSAs.
2.3 Site Selection
To assure that all industrial laundering facilities were
included in the target population for potential site surveys, the
total known list of facilities in both SIC 7213 and SIC 7218 in
the five SMSAs was used for the sampling frame. Facilities were
numbered, and, from a list of random numbers, were assigned an
order from which to be chosen to be surveyed.
Through telephone contacts, sites were either scheduled for
survey visits or eliminated from the survey. When requested,
Section 308 letters were sent to scheduled sites. The following
criteria were used for scheduling sites:
a) Must not be a small operator; must have
at least ten employees.
b) Must have industrial laundering as at least
ten percent of plant operation.
Table 2-4 shows the number of sites contacted and scheduled
for survey. Los Angeles sites were randomly selected and
contacted from telephone directory listings before Dun and
Bradstreet listings were available.
2.4 Site Survey
For consistency, a survey form was developed for use by the
field survey personnel. The form includes information regarding
plant production, waste water generation, existing treatment and
space available for treatment units. A copy of the form is
attached. In addition to completing the forms, survey personnel
prepared diagrams indicating potential locations for treatment
systems.
The treatment system for which space requirements were
B-5
-------
TABLE 2-3. NUMBER OF INDUSTRIAL LAUNDERiiRS* IN FIVE
LARGEST SMSAs. (SIC 7218)
fBB9iS«S8S39S8S83
Standard
Metropolitan
Statistical
Araa
AC€a
New York
Los Angeles
Philadelphia
Chicago
Detroit
Subtotal
Remainder of U.
In SMSA
Outside SMSA
National Total
Dun & Bradstreet
Market
Identifiers
SIC 7218 SIC 7218
and only
SIC 7213
118 35
75 27
45 15
60 29
53 26
351 132
S.
1414 419
705 185
2470 736
Net
Composite
Sampling
IP *p am a
f t BU1C
163
137
102
100
90
592
Estimated
Industry
Total Number
of Establishments
%f ± bw W 0 mf A * ^ • l»H » & * *• ^
(SIC 7218 only)
48
49
34
48
44
223
708
312
1243
* Establishments which have SI 721B as primary through sixth
Standard Industrial Classification.
B-6
-------
TABLE 2-4. NUMBER OF LAUNDRY SITES CONTACTED
AND SCHEDULED
SMSA Composite Contacted Scheduled
Sampling Frame
New York
Los Angeles
Philadelphia
Chicago
Detroit
163
137
102
100
90
93
28
43
44
42
14
12
9
8
7
Total 592 250 50
B-7
-------
developed is system la: equalization fallowed by dissolved air
flotation (DAP). The following units and equipr snt are included:
o equalization tank (above or below grade)
o dissolved air flotation (DAF)
o sludge handling or vacuum filtration unit
(only necessary for.flows over 48,000 gpd)
o chemical storage
Table 2-5 presents space requirements for this system for a
range of industrial laundry waste water flows. For sites where
other operations take place, i.e., linen supply, diaper service,
etc., only the flow from industrial laundering was considered for
treatment.
Where adequate space was not readily available inside or
outside a laundry facility, the possibility of relocating
equipment to provide space was examined. Where no space could be
provided, the possibility of acquiring adjacent property for the
location of treatment equipment was examined.
Although 50 sites were scheduled, only 45 were successfully
surveyed. Once the survey personnel were in the field, two sites
were found to not fit the required criteria; i.e., did not
conduct industrial laundering despite telephone confirmation of
such, and three sites refused admittance despite receipt of
Section 308 letters. Table 2-6 shows the breakdown of sites
visited and actually surveyed.
3.0 SURVEY RESULTS
Tables 3-1 through 3-5 present data on individual sites
surveyed in the five SMSAs.
The following items are presented in the tables:
o Number of employees - total number of plant employees
including office staff and drivers.
o Percent industrial - where other operations take place
at the same facility, this figure represents the
percent of total production (pounds per year)
attributed to industrial laundry.
o Industrial production - pounds per year processed.
B-B
-------
TABLE 2-5. SPACE REQUIREMENTS FOR TREATMENT OF
INDUSTRIAL LAUNDERING WASTE WATER
Industrial Laundering
Waste Water Flow
(gpd)
Space Requirement
for Treatment (sq.ft.)*
2,400
4,800
7,200
9,600
14,400
2 4,.00.0
36,000
48,000
72,000
96,000
120,000
135,000
150,000
250,000
40
54
70
84
LOS
107
160
200
250
300
400-
450
500
800
* Assuming equalization tanks below grade,
B-9
-------
TABLE 2-6. INDUSTRIAL LAUNDERING SITES SCHEDULED
AND SURVEYED (SIC 7218)
— m3«3 —3383 = 888883888 =38SSSS=S383aS33S8S8=SSSB3tS = SS8S««B388S88S338S3S
Number of Sites Eliml- Number of
Sites nated in Sites Refusing Sites
SMSA Scheduled Field Admittance Surveyed
New York 14 1 2 11
Los Angeles 12 12
Philadelphia 9 18
Chicago 81 7
Detroit 7 ?
Totals 50 2 3 45
B-10
-------
TABLE 3-1. SURVEY RESULTS - NEW YORK
Code | No. Pet * Production Industrial Sep. Existing. EqualIz. Required. Available Cose
Em pi . Indus t Lb/Year Plow Stream Treatment Capacity Equipment Space
Gal/Day
2
H
N
N
N
N
N
N
N
N
N
N
N
1
2
3
4
5
6
7
8
9
10
11
136
44
60
187
25
15
13
73
217
12
50
90
100
100
10
100
100
100
100
10
100
10
4,000,
355,
1,900,
850,
130,
450,
127,
1,870,
1,400,
40,
130,
000
600
000
000
000
000
000
000
000
000
000
40
5
68
10
2
8
2
24
B
1
2
,000 NO 1 2,000
,000
,000 1 3,000
,600 NO 1 15,000
,500
,000
,000
,000
,500 NO 1 15,000
,741
,500 NO 1 10,000
1
2
1
2
1
2
2
1
2
1
3
1
2
1
2
2
1
2
1
2
INT
INT
— —
EXT
EXT
EXT
EXT
INT
INT
TNT
INT
6
3
3
3
5
3
4
4
-------
TABLE 3-2. SURVEY RESULTS - LOS ANGELES
Coda I No. Pet . Production Industrial Sep. Existing. Equaliz. Required. Available Cost
Em pi Indust Lb/Year Plow Stream Treatment Capacity Equipment Space -Items
Gal/Day
L
L
L
L
S1"
L
L
L
L
L
L
L
1
2
3
4
5
6
7
8
9
10
11
12
45
62
16
40
20
36
50
70
48
70
52
40
100
95
100
20
100
100
25
100
40
40
100
100
1,000,
3,750,
151,
900,
1,070,
1,143.
1,065,
3,795,
000
000
800
000
000
000
000
000
560,000
520,000
3,120,000
1,200,000
16,000
19,000 NO
4,500
10,600 NO
8,500
13,100
11,000 YES
82,000
11,200 NO
19,000
42,000
15,000
1
1
1
1
1
1
1
1
1
1
1
1
10,
5,
3,
50,
2,
5,
1,
18,
2,
5,
000
000
000
000
500
000
500
000
000
600
1,200
2
2
2
1
2
2
1
2
2
1
2
2
1
2
2
1
2
EXT
EXT
EXT
INT
EXT
EXT
EXT
EXT
EXT
EXT
EXT
EXT
-------
TABLE 3-3. SURVEY RESULTS - PHILADELPHIA
Coda | No. Pet . Production Industrial Sep. Existing. Equallz. Required. Available Cost
Empi Indust Lb/Year Flow Stream Treatment Capacity Equipment Space Items
'Gal/Day
p 1
P '2
P 3
P 4
P 5
T 6
P 7
P 8
70
BO
100
175
60
64
43
51
100
100
100
40
100
100
100
30
2,700,
1.716,
•5,100V
6,240,
750,
1,872,
654,
1,650,
000
000
000
000
000
000
000
000
28,000
20,000
60,000,
75,500 NO
20,000
26,000
14,000
36,000 NO
1
1
1
2
1
1
1
1
1
7
1
5
5
10
9
1
,000
,000
,600
,000
700
,000
,000
,350
1
2
1
2
1
Z
1
2
2
2
1
2
EXT
EXT
EXT
INT
INT
INT
EXT
INT
3
3
3
4
4
3
-------
TABLE 3-4. SURVEY RESULTS - CHICAGO
Code I No. Pet . Production Industrial Sep. Existing. Equaliz. Required. Available Cost
Empl Indust Lb/Year Flow Stream Treatment Capacity Equipment Space Items
Gal/Day
r.
C 1
C 2
C 3
C 4
C 5
C 6
C 7
130
300
29
80
100
50
100
25
30
100
100
100
100
100
2,540,
B, 514,
762.
1,404,
624,
1,900,
6,175,
000
000
000
000
000
000
000
30,000 NO
150,000 YES
10,000
20 ',000
40,000
45,000
76,000
1
1
2
1
2
1
2
1
2
1
1
2
30,
75,
5,
1*
7,
30,
50,
000
000
000
BOO
500
000
000
2
1
2
1
2
1
2
1
2
1
2
1
2
EXT
INT
INT
INT
EXT
EXT
EXT
3
4
''
3
3
3
-------
TABLE 3-5. SURVEY RESULTS - DETROIT
Code f No. Pet . Production Industrial Sep. Existing. Equaliz. Required. Available Cost
Em pi Indust Lb/Year Flow Stream Treatment Capacity Equipment Space Items
Gal/Day
D 1 300 100 11,000,000 250,000
D 2 500 100 10..000.000 135,000
D 3 IB 100 500,000
D 4 60 15 936,000
«
CDS 200 100 500,000
D 6 12 40 122,000
D 7 55 100 520,000
50,000
35,000
16,000
15,000 NO
70,000
6,000 NO
50,000
1
1
1
1
1
15,000
25,000
5,500
17,000
6,000
1
2
2
1
2
1
2
2
1
2
1
2
EXT
INT
EXT
INT
EXT
EXT
INT
3
4
3
4
J
3
-------
o Industrial vaste water -iG« -
water attributed to industrial production. Where
flow was'hot known*,* it was assumed to be proportional
>.o industrial production.
o -Separate-streams - where other operations take place,
existence or not of "Segregated waste flows was
identified.
o Existing 'treatment - equalization, dissolved
air flotation.(2)
o Equalization capacity - where equalization exists,
the capacity is presented.
o Required equipment -.an, identification of
which units would be required at each site. Where
equalization already exists but is not of sufficient
capacity-or could- not be used because of mixing with
other wastes (i.e., lin;en wastes) , it is indicated as
being required. Note; Most sites in Chicago have
treatment In .piacTTctriirindustrial l.a.qndry wastes due to a
recent* municipal regulation. Required [treatment units
in the table reflect units added .as a result of local
regul-atlon's;
o Space available - indicates interior or exterior
o Cost items'- an-identification of specific cost
items related to the location of a treatment system.
The- items' include:
_3 - housing required for. exterior location,
4 - interior -modification required such as
relocating equipment or interior constraints
to excavation,
5 - acquisition :of; additional, property,
6 - relocation of facility when no adjacent land is
available. .
3.1 Cost Estimates
Foil-owing-the., survey, the. costs for making or acquiring
.space -for efaeh- si±e not having readily -available space were
developed.
o Sousing - a'fc £25 per square foot.,,, con's t ruction of an
enclosure to house a.DAP unit.
B-16
-------
I
o Equipment relocation - all but one site requiring
relocation were for air.or equipment:. One. site in
Chicago required relocation of aajor equipment and the
cost estimate is from plant management. For sites where
interior excavation would be required, an estimate of
excess labor costs was made based on excavation volume.
o Acquisition of additional property - only one site
required such. An estimate of property values in the
area was obtained from local authorities.
o Relocation of facility - one site, surrounded by streets
could not acquire additional space. No cost estimate was
made for relocating should it be required.
Table 3-6 summarizes1 the survey findings by the type of
locational costs to.be incurred by sites in each- SMSA.
Tab-le 3-7. pr.ese.nts the estimated costs to be -incurred by
surveyed ' facilities ' without readily available, space. Also
included' in'the 'liable are-estimated capital cojsfes .pf treatment
for each facility as presented in the development document, and
the subsequent, .percent increase in that cost due to additional
locational costs'*
Not. included..in the cost estimates: •.for any facilities are
costs for segregating "waste streams-or the. additional,, "'cost for
placing equalization tanks below grade. The cost-of segregating
industrial laundry wastes where other operations take place would
be minor, but could hamper operations at som-e small facilities.
The additional cost of below grade equalization is estimated at a
maximum of 10 percent of the cost of an .equalization tank above
ground.
3.2 Statistical Analysis'of Survey Results.
From the random sample of the five largest SMSAs, confidence
interval estimates were computed for the fraction of the industry
which is expected to be impacted by locational.-costs for waste
water treatment.
Stratified'sampling parameters for each- of • the ...five SMS As
were given in Table 2-3. Results of the survey.-were given , in
Table 3-6. For the purpose of interval estimates, thosepdatV in
Table 3-6 are. recapped in Table 3-8 in terms of extensive,
moderate, or no co's't impact -traceable $o> Vocational
considerations.
Using standard stratified sampling estimation techniques
B-17
-------
TABLE 3-6. SUMMARY--OF PROVISIONAL COSTS FOR INDUSTRIAL LAUNDERERS
TO ACCOMMODATE WASTE .TREATMENT SYSTEMS
SMSA Number .
Facilities None
Visited
Modifications Required
Interior Exterior
NY
LA
Phil.
Detroit
Chicago
Survey
Total
Average
per
Laundry
Facility
Exten- Land and Reloca-
Minor sive Housing Housing tion
11
12
8
7
7
45
4
12
2
1
1
2(32,000)
3 {$13,500) 1 ($35, 400) (1)
2($11,000) 4{$38,700)
2($8,500) 4($57,000)
1($5,000) 1($10Q,000)4($47,90;Q)
20 7 1 15 1. (1)
($26,500) ($100,000) ($157,000) ($35,400)
$3790 $100,000
$10,500 $35,400
(1)
No cost estimate made.
B-1B
-------
TABLE 3-7. INCREASE IN CAPITAL COSTS DUE TO
ADDITIONAL LOCATIONAL COSTS
saeseassss:
Facility
N-3
N-4
N-5
N-6
N-7
N-9
N-ll
P-l
P-2
P-3
P-4
P-5
P-7
C-l
C-2
C-4
C-5
C-6
C-7
D-l
D-2
D-3
D-4
D-5
D-6
Industrial
Flow (gpd)
68,000
10,600
2,500
8,000
2,000
8,500
2,500
28,000
20,000
60 , oao
75,500
20,000
14,000
30,000
150,000
20,000
40,000
45,000
76,000
250/000
135,000
16,000-
15,000
70,000
6,000
Approximate
Capital Cost
of Treatment
160,000
.52,oog
38,000
45,000
35,000
46,000
38,000
95,000
73,000
150,000
165,000
73,000
58,000
100,000
215,000
73,000
120,000
130,000
165,000
280,000
208,000
60,J)00
58,000
160,000
43,000
Additional
Location's! :
Cost
*
7i350
3,750
35,400
2,400
1,000
1,000
10,000
7,35"0
14,000
g,5«fd
2,500
7,350
10,000
100,000
5,000
10,900
10,900
16,100
31, .250
7, -500
7,500
1,'OOff
14,000
4,400
Percent
Increase of
Gap. Cost
*
14
10
79
7
2
3
10
10
9
5
3
13
10
46
7
9
8
10
11
4
12
•2
9
10
* This site had no space and could not acquire adjacent
land. No cost estimate was made.
B-19
-------
TABLE 3-8. SUMMARY OF SAMPLE PROPORTIONS AFFECTED BY SPACE
REQUIREMENTS FOR EFFLUENT TREATMENT SYSTEMS (SIC 7218 ONLY)
SMSA Stratum
Size
NY 48
LA 49
Phil. 34
Chicago 43
Detroit 44
Sub .total 223
Remainder.
of U.S. 1020
Total 1243
Sam pi e
Size
11
12
8
7
7
45
Sampl ing.
Fraction
.229
.244
.235
.146
.159
.20?
I
None
4
12
2
1
1
20
.ocational (
Moderate
5
0
6
5
6
22
:osts
Extensive
2
0
0
1
0
3
B-20,
-------
based upon correction factors for finite strata, one obtains the
following statistics:
p = 0.0699; estimated fraction of five SMSAs
with extensive locatiofial costs.
s « 0.0370; standard error of estimate p
T • 16; estimated number of laundries out of
223 with extensive locational costs.
The estimate p, above/ is - the point estimate. Assuming
normal approximation to the sampling distribution of p, one can
calculate an upper confidence limit for P, the fraction .of the
five SMS As affected. Since confidence intervals 'depend upon the
degree of confidence specified, the following alternate interval
estimates are obtained:
Pr(0
-------
small as well-as-large ieriiities.
o Approximately seven percent o£ the industrial
laundry facilities in the five SMSAs will incur
extensive locational costs.
o Approximately. «»3 percent of the industrial laundry
facilities in the five SMSAs will incur zero to
moderate locational costs.
Although the results of the" survey may not.necessarily be
reflected nationwide, it can be assumed that the sampling frame
of aajor metropolitan areas represents an-upper bound of impact
and that .natiQnvi.de, this impact may be even less.
B-22
-------
Personnel.
UDNDJIXES stucrex FOBM
Name of Facility:
Address:
Telephone :_
Contact:
Title:
1. Classification of Primary Business
SIC 7213 Linen Supply
SIC 7218 Industrial Laundry
2. Plant Operation
a. Total number of Employees
b. Hours of Washroom Operation
c. Days/Yr. of Washroom Operation
3. Processes Used Approximate number of pounds processed annually
a. Water Wash Only
b. Dual-Process
c. Dry Cleaning Only
4. Annual Plant Production
a. Annual Poundage Processed
1. Percent Linen Supply
2. Percent Industrial
3^ Percent Other
(Family, Institutional, Diaper Service, Etc.)
4. Have you bad any recent increases or decreases in
the percent of Industrial Laundry handled?
How much? Cpast year)
B-23
-------
S. Do you have the capability to handle future increases
in the percent of Industrial Laundry? ___
HOW much? __
S. Hater Psage and Flow Patterns
a. Hater Source
1. City
2. Well J
LS XL
3. Other .**—
b. Estimate of daily water use 'ffir laundering GPD
Source '(toeter reading, water biU,, guess, etc.)
c. PeaJe'washvatBr-fiow--ia gallons per miiiute GPM
Source. (sanitary, distric surcharge, meter reading, et
d. Duration, of peak flow
e. Battem of flow
6. Effluent Discharge
a. if both Linen Supply and Industrial Laundering are done:
1. Are wastewater streams separate?
•2. If not, how .can this be accomplished?
b. •Method, of .Discharge •
1.. Sa.onin.icipal sewer connection
2.. Dire.etly to surface water
7. Ing-Slant Controls
1. lint screwi
2. Catch, basin or sunp (size)
B-24
-------
3. Screen at bottom of catch basin
4. Heat Reclaimer
5. Other (specify)
Wastewater Treatment
a* Is vasfcewater treatment practiced?
b. If "yes", please describe; _
c. Is wastewater recycled?
1. What percent?
9. Space Availability
(Please diagram all areas)
a. Readily available space (clear, unused areas)
1. Location (interior, exterior, basement. 'roof, etc.)
2. Distance from washroom equipment or. available tank
Distance from sewer connection
3. Availability of power and distance from power supply
Availability of lights _
Availability of heat _
4, Will housing be. necessary? __
b. If space is not readily available, then existing space, that could be
made-available.
1. Location
2. Distance from equipment and sewer
B-25
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3. Availability of utilities and distance from power twpply.
4. Necessary modifications (briefly describe)
a. Movement of light equipment_ _—_—.
b. Movement of heavy equipment
c. Breaking through concrete
Walls
Floor
d. Can equipment necessary for performing
modifications gain access to the area
If not, what will have to be done to permit access
e. Bow will implementation, of. modifications Impact
plant operation?
f. Hill housing of equipment be necessary?
c. If no space is availableitthen, space that can be acquired;
1. Renting ,
Leasing
or Purchase
a. Location
b. Distance from equipment and sewer
c. Availability of utilities
10. Summary of Cost Itmes (piping, reinforcements, etc.)
B-26
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