United States
Environmental Protection
Agency
Office Of Water
(4303)
EPA 821-R-95-006
January 1995
&EPA Development Document For
Proposed Effluent Limitations
Guidelines And Standards For
The Centralized Waste
Treatment Industry
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DEVELOPMENT DOCUMENT
FOR
PROPOSED EFFLUENT LIMITATIONS
GUIDELINES AND STANDARDS
FOR THE
CENTRALIZED WASTE TREATMENT INDUSTRY
Carol M. Browner
Administrator
Robert Perciasepe
Assistant Administrator, Office of Water
Thomas P. O'Farrell
Director, Engineering and Analysis Division
Elwood H. Forsht
Chief, Chemicals and Metals Branch
Written and Prepared by:
Debra S. DiCianna
Project Manager
January 1995
U.S. Environmental Protection Agency
Office of Water
Washington, DC 20460
Additional Support by Contract No. 68-C1-0006
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TABLE OF CONTENTS
EXECUTIVE SUMMARY ES-1
SECTION 1 STATUTORY REQUIREMENTS 1-1
1.1 LEGAL AUTHORITY 1-1
1.1.1 Best Practicable Control Technology Currently Available (BPT)
(Section 304(b)(1) of the CWA) 1-1
1.1.2 Best Conventional Pollutant Control Technology (BCT)
(Section 304(a)(4) of the CWA) 1-2
1.1.3 Best Available Technology Economically Achievable (BAT)
(Sections 304(b)(2)(B) of the CWA) 1-3
1.1.4 New Source Performance Standards (NSPS) (Section 306 of the
CWA) ...1-3
1.1.5 Pretreatment Standards for Existing Sources (PSES)
(Section 307(b) of the CWA) 1-4
1.1.6 Pretreatment Standards for New Sources (PSNS) (Section 307(b)
of the CWA) 1-4
1.2 SECTION 304(M) REQUIREMENTS AND LITIGATION 1-5
SECTION 2 DATA COLLECTION 2-1
2.1 CLEAN WATER ACT SECTION 308 QUESTIONNAIRES 2-1
2.1.1 Development of Questionnaires 2-1
2.1.2 Distribution of Questionnaires 2-4
2.2 SAMPLING PROGRAM 2-5
2.2.1 Pre-1989 Sampling Program 2-5
2.2.2 1989 -1993 Sampling Program 2-6
2.2.3 1994 Sampling Program 2-9
SECTION 3 DESCRIPTION OF THE INDUSTRY 3-1
3.1 GENERAL INFORMATION 3-2
3.2 WASTES RECEIPTS 3-3
3.2.1 Waste Receipt Types 3-4
3.2.2 Procedures for Receipt of Wastes 3-6
3.3 DISCHARGE INFORMATION 3-8
3.4 TREATMENT RESIDUALS 3-9
3.5 INDUSTRY SUBCATEGORIZATION 3-10
3.5.1 Development of Subcategorization Scheme 3-11
3.5.2 Proposed Subcategories 3-12
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TABLE OF CONTENTS (continued)
SECTION 4 WASTEWATER USE AND WASTEWATER CHARACTERIZATION .. 4-1
4.1 WATER USE AND SOURCES OF WASTEWATER 4-1
4.2 WATER USE BY DISCHARGE 4-4
4.3 WATER USE BY SUBCATEGORY 4-5
4.4 WASTEWATER CHARACTERIZATION 4-6
4.4.1 Pollutant Parameters 4-7
4.4.2 Priority and Non-Conventional Pollutants 4-9
4.5 WASTEWATER POLLUTANT DISCHARGES . 4-13
4.5.1 Metals Subcategory Current Performance 4-13
4.5.2 Oils Subcategory Current Performance 4-18
4.5.3 Organics Subcategory Current Performance 4-21
SECTION 5 POLLUTANTS AND POLLUTANT PARAMETERS
SELECTED FOR REGULATION 5-1
5.1 POLLUTANT PARAMETERS 5-1
5.2 PRIORITY AND NON-CONVENTIONAL POLLUTANTS 5-2
5.3 SELECTION OF POLLUTANTS TO BE REGULATED FOR PSES AND
PSNS 5-6
5.3.1 Pass-Through Analysis Approach 5-7
5.3.2 50 POTW Study Data Base 5-8
5.3.3 RREL Treatability Data Base 5-9
5.3.4 Final POTW Data Editing 5-9
5.3.5 Final Pass-Through Analysis Results 5-14
5.4 REFRENCES 5-19
SECTION 6 WASTEWATER TREATMENT TECHNOLOGIES 6-1
6.1 PHYSICAL/CHEMICALTTHERMAL WASTEWATER TREATMENT
TECHNOLOGIES 6-1
6.1.1 Chemical Precipitation 6-2
6.1.2 Clarification 6-10
6.1.3 Plate and Frame Pressure Filtration 6-12
6.1.4 Emulsion Breaking 6-14
6.1.5 Equalization 6-16
6.1.6 Air Stripping 6-17
6.1.7 Multi-media Filtration 6-21
6.1.8 Carbon Adsorption 6-24
6.1.9 Cyanide Destruction 6-30
6.1.10 Chromium Reduction 6-33
6.1.11 Electrolytic Recovery 6-36
6.1.12 Ion Exchange 6-37
6.1.13 Gravity Separation 6-41
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TABLE OF CONTENTS (continued)
6:1.14 Dissolved Air Flotation 6-42
6.2 BIOLOGICAL WASTEWATER TREATMENT TECHNOLOGIES 6-45
6.2.1 Sequencing Batch Reactors 6-47
6.2.2 Biotowers 6-50
6.2.3 Activated Sludge 6-52
6.3 ADVANCED WASTEWATER TREATMENT TECHNOLOGIES 6-54
6.3.1 Ultrafiltration 6-54
6.3.2 Reverse Osmosis 6-57
6.3.3 Lancy Filtration 6-60
6.3.4 Liquid Carbon Dioxide Extraction 6-62
6.4 SLUDGE TREATMENT AND DISPOSAL 6-63
6.4.1 Plate and Frame Pressure Filtration 6-66
6.4.2 Belt Pressure Filtration 6-68
6.4.3 Vacuum Filtration 6-70
6.4.4 Filter Cake Disposal 6-72
6.5 REFERENCES 6-73
SECTION 7 COST OF TREATMENT TECHNOLOGIES 7-1
7.1 COSTS DEVELOPMENT 7-1
7.1.1 Technology Costs 7-1
7.1.2 Option Costs 7-4
7.2 PHYSICAL/CHEMICAL/THERMAL WASTEWATER TREATMENT
TECHNOLOGY COSTS 7-4
7.2.1 Chemical Precipitation ; 7-4
7.2.2 Clarification 7-14
7.2.3 Plate and Frame Pressure Filtration - Liquid Stream 7-16
7.2.4 Equalization 7-20
7.2.5 Air Stripping 7-21
7.2.6 Multi-Media Filtration 7-23
7.2.7 Carbon Adsorption 7-24
7.2.8 Cyanide Destruction 7-26
7.2.9 Chromium Reduction 7-28
7.3 BIOLOGICAL WASTEWATER TREATMENT TECHNOLOGY
COSTS 7-30
7.3.1 Sequencing Batch Reactors 7-30
7.4 ADVANCED WASTEWATER TREATMENT TECHNOLOGY
COSTS 7-31
7.4.1 Ultrafiltration 7-31
7.4.2 Reverse Osmosis 7-33
7.5 SLUDGE TREATMENT AND DISPOSAL COSTS 7-34
7.5.1 Plate and Frame Pressure Filtration - Sludge Stream 7-34
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TABLE OF CONTENTS (continued)
7.5.2 Filter Cake Disposal 7-36
7.6 ADDITIONAL COSTS 7-38
7.6.1 Retrofit Costs 7-38
7.6.2 Monitoring Costs 7-38
7.6.3 RCRA Permit Modification Costs 7-40
7.6.4 Land Costs 7-41
7.7 REFERENCES 7-44
SECTION 8 DEVELOPMENT OF LIMITATIONS AND STANDARDS 8-1
8.1 ESTABLISHMENT OF BPT 8-1
8.1.1 Rationale for Metals Subcategory BPT Limitations 8-3
8.1.2 Rationale for Oils Subcategory BPT Limitations 8-9
8 1.3 Rationale for Organics Subcategory BPT Limitations 8-14
8-2 BCT 8-19
8.3 BAT 8-19
8.4 NSPS 8-20
8.5 PSES • 8-21
8.6 PSNS 8'22
8.7 COST OF TECHNOLOGY OPTIONS 8-22
8.7.1 Proposed BPT Costs 8-23
8.7.2 Proposed BCT/BAT Costs 8-24
8.7.3 Proposed PSES Costs 8-24
8.8 POLLUTANT REDUCTIONS 8-25
8.8.1 Conventional Pollutant Reductions 8-25
8.8.2 Priority and Nonconventional Pollutant Reductions 8-26
SECTION 9 NON-WATER QUALITY IMPACTS 9-1
9.1 AIR POLLUTION 9-1
9.2 SOLID AND OTHER AQUEOUS WASTE 9-2
9.2.1 Filter Cake 9-3
9.2.2 Reverse Osmosis Concentrate 9-4
9.2.3 Ultrafiltration Concentrate 9-5
9.2.4 Spent Carbon 9"5
9.2.5 Air Stripper Oxidizer Catalyst 9-6
9.3 ENERGY REQUIREMENTS 9-7
9.4 LABOR REQUIREMENTS 9-8
IV
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TABLE OF CONTENTS (continued)
SECTION 10 IMPLEMENTATION 10-1
10.1 APPLICABLE WASTE STREAMS 10-1
10.2 DETERMINATION OF SUBCATEGORIES 10-2
10.3 ESTABLISHING LIMITATIONS AND STANDARDS FOR FACILITY
DISCHARGES 10-4
10.3.1 Facilities with One Operation 10-4
10.3.2 Facilities with Operations Classified in Multiple Subcategories 10-5
Appendix A RCRA And Waste Form Codes Reported by Facilities in 1989
Appendix B Initial Pollutants Included in Sampling Program
Appendix C Acronyms and Definitions
Index
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LIST OF TABLES
ES-1 Technology Basis for BPT Effluent Limitations ES-3
ES-2 Cost of Implementing Regulations [in millions of 1993 dollars] ES-4
3-1 RCRA Codes Reported by Facilities in 1989 3-4
3-2 Waste Form Codes Reported by Facilities in 1989 3-5
3-3 Quantity of Waste Received for Treatment 3-6
3-4 Distribution of Facility Discharge 3-8,
3-5 Quantity of Wastewater Discharged in 1989 3-9
3-6 Quantity of Treatment Residuals in 1989 3-10
4-1 Comparison of total facility discharge to total CWT discharge 4-4
4-2 Summary of Wastewater by Subcategory 4-6
4-3 Influent Concentrations Ranges for Selected Pollutant Parameters 4-8
4-4 Range of Metal Pollutant Influent Concentrations (mg/l) 4-10
4-5 Range of Organic Pollutant Influent Concentrations (mg/l) 4-11
4-6 Metals Subcategory Current Performance 4-16
4-7 Oils Subcategory Current Performance 4-19
4-8 Organics Subcategory Current Performance 4-22
5-1 Pollutants Selected for Regulation 5-3
5-2 Pollutants Excluded from Regulation Due to the Concentration Detected .... 5-4
5-3 Pollutants Excluded from Regulation Due to Lack of Detection or Analysis
at the Technology Option Facility 5-5
5-4 Pollutants Excluded from Regulation Due to Ineffective Treatment 5-6
5-5 Generic Removals for Group C: Hydrocarbons 5-11
5-6 Generic Removals for Group Q: Ethers 5-11
5-7 Final POTW Removals for CWT Pollutants 5-12
5-8 Volatile Override Analysis for CWT Pollutants 5-15
5-9 Final Pass-Through Results for Metals Subcategory Option 3 5-16
5-10 Final Pass-Through Results for Oils Subcategory Options 2 and 3 5-17
5-11 Final Pass-Through Results for Organics Subcategory Option 1 5-18
6-1 Chemical Precipitation System Performance Data for CWT QID 059 ... 6-6
6-2 Chemical Precipitation System Performance Data for CWT QID 105 6-6
6-3 Chemical Precipitation System Performance Data for CWT QID 230 6-7
6-4 Selective Metals Precipitation (Solid Metals Recovery) System
Performance Data for CWT QID 130 6-7
VI
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LIST OF TABLES (continued)
6-5 Selective Metals Precipitation (Liquid Metals Recovery) System
Performance Data for CWT QID 130 6-8
6-6 Secondary Precipitation System Performance Data for CWT QID 130 ...... 6-8
6-7 Tertiary Precipitation System Performance Data for CWT QID 130 6-9
6-8 Overall Metals Precipitation System Performance Data for CWT QID 130 ... 6-9
6-9 Air Stripping System Performance Data 6-21
6-10 Carbon Adsorption System Performance Data for Organics Subcategory .. 6-28
6-11 Carbon Adsorption System Performance Data for Oils Subcategory 6-29
6-12 Sequencing Batch Reactor System Performance Data 6-49
6-13 Ultrafiltration System Performance Data 6-56
6-14 Reverse Osmosis System Performance Data 6-59
6-15 Lancy Filtration System Performance Data 6-62
6-16 Liquid CO2 Extraction System Performance Data 6-65
7-1 Standard Capital Cost Factors 7-2
7-2 Standard O & M Cost Factors 7-3
7-3 CWT Subcategory Options 7-5
7-4 Monitoring Costs for the CWT Industry Cost Exercise 7-40
7-5 RCRA Permit Modification Costs Reported in WTI Questionnaire 7-41
7-6 State Land Costs for the CWT Industry Cost Exercise 7-43
8-1 BPT Effluent Limitations for the Metals Subcategory 8-6
8-2 BPT Effluent Limitations for the Oils Subcategory (mg/l) 8-11
8-3 BPT Effluent Limitations for the Organics Subcategory (mg/l) 8-16
8-4 Cost of Implementing Proposed BPT Regulations [in millions of 1993 dollars]8-23
8-5 Cost of Implementing Proposed PSES Regulations [in millions of 1993 dollar8}24
8-6 Reduction in Direct Discharge of Priority and Nonconventional Pollutants After
Implementation of Proposed BPT/BAT Regulations 8-27
8-7 Reduction in Indirect Discharge of Priority and Nonconventional Pollutants After
Implementation of Proposed PSES Regulations 8-28
9-1 Air Pollution Reductions for the CWT Industry 9-2
9-2 Filter Cake Generation for the CWT Industry . 9-4
9-3 Reverse Osmosis Concentrate Generation for the CWT Industry 9-4
9-4 Ultrafiltration Concentrate Generation for the CWT Industry 9-5
9-5 Activated Carbon Requirements for the CWT Industry 9-6
9-6 Air Stripper Oxidizer Catalyst Requirements for the CWT Industry . 9-6
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LIST OF TABLES (continued)
9-7 Energy Requirements for the CWT Industry 9-7
9-8 Labor Requirements for the CWT Industry 9-8
10-1 Pollutant Concentrations for Determination of Subcategory 10-3
VIII
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LIST OF FIGURES
3-1
3-2
4-3
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
6-9
6-10
6-11
6-12
6-13
6-14
6-15
6-16
6-17
6-18
6-19
6-20
6-21
6-22
6-23
6-24
Distribution of Centralized Waste Treatment Facilities
Waste Receipt Procedures
Example of Non-CWT Wastewater Addition
Chemical Precipitation System Diagram
Clarification System Diagram
Plate and Frame Pressure Filtration System Diagram
Emulsion Breaking System Diagram
Equalization System Diagram
Air Stripping System Diagram
Multi-Media Filtration System Diagram
Carbon Adsorption System Diagram
Cyanide Destruction System Diagram
Chromium Reduction System Diagram
Electrolytic Recovery System Diagram
Ion Exchange System Diagram
Gravity Separation System Diagram
Dissolved Air Flotation System Diagram
Sequencing Batch Reactor System Diagram
Biotower System Diagram
Activated Sludge System Diagram
Ultrafiltration System Diagram
Reverse Osmosis System Diagram
Lancy Filtration System Diagram
Liquid CO2 Extraction System Diagram
Plate and Frame Pressure Filtration System Diagram
Belt Pressure Filtration System Diagram
Vacuum Filtration System Diagram
3-2
3-7
4-13
6-4
6-11
6-13
6-15
6-18
6-19
6-23
6-25
6-31
6-35
6-38
6-40
6-43
6-44
6-48
6-51
6-53
6-55
6-58
6-61
6-64
6-67
6-69
6-71
IX
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EXECUTIVE SUMMARY
EPA is proposing technology-based limits for the discharge of pollutants into
navigable waters of the United States and into publicly-owned treatment works by existing
and new facilities that are engaged in the treatment of industrial waste from off-site
facilities - the Centralized Waste Treatment Point Source Category. This proposed
regulation would establish effluent limitations guidelines for direct dischargers based on
the following treatment technologies: "best practicable control technology" (BPT), "best
conventional pollutant control technology" (BCT), and "best available technology
economically achievable" (BAT). New source performance standards are based on "best
demonstrated technology." The proposal also would establish pretreatment standards for
new and existing indirect dischargers.
EPA identified 85 facilities which are included in the Centralized Waste Treatment
Industry. The proposed effluent limitations guidelines and standards are intended to cover
wastewater discharges resulting from treatment of, or recovery of components from,
hazardous and non-hazardous industrial waste received from off-site facilities by tanker
truck, trailer/roll-off bins, drums, barges, or other forms of shipment. Any discharges
generated from the treatment of wastes received through an open or enclosed conduit (i.e.,
pipeline, channels, ditches, trenches, etc.) from the original source of waste generation are
not included in the regulation. EPA has estimated that the proposed regulation will apply
to 72 facilities which discharge wastewater. Sixteen facilities discharge wastewater
directly; and 56 discharge indirectly to publicly-owned treatment works (POTW). Facilities
in the Centralized Waste Treatment Industry accept many types of wastes for treatment
or recovery. The proposed regulation applies to the following activities:
Subcategory A: Discharges from operations which treat, or treat and recover
metals from, metal-bearing waste received from off-site,
ES-1
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Subcategory B: Discharges from operations which treat, or treat and recover
oil from, oily waste received from off-site, and
Subcategory C: Discharges from operations which treat, or treat and recover
organics from, other organic-bearing waste received from off-site.
Such operations would include facilities whose exclusive operation is the treatment of off-
site generated industrial waste as well as industrial or manufacturing facilities that also
accept waste from off-site for centralized treatment.
The EPA evaluated various treatment technologies in developing the effluent
limitations and standards. Table ES-1 lists the treatment technologies that are proposed
for BPT limitations. Two options are being proposed for the Oils Subcategory because
limitations for the less expensive proposed option are significantly less stringent than
limitations for other industries. However, the more stringent treatment option has a greater
cost The treatment technologies proposed for BPT are the same treatment technologies
proposed for BCT, BAT, NSPS, PSES, and PSNS.
After identifying treatment technologies, the EPA developed a model for calculating
facility costs to upgrade present facility operations to the technology options proposed.
Table ES-2 presents the capital and annual operating and maintenance costs associated
with the proposed technology options. In addition to the costs for upgrading facility
operations, costs were also calculated for modifying RCRA permits for facilities which
accept hazardous waste for treatment and for the additional monitoring requirements for
the proposed regulation. Overall, the proposed technology options are estimated to have
an annualized cost of $49 million for the less stringent Regulatory Option 1 and $74 million
for the more stringent Regulatory Option 2.
ES-2
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Table ES-1. Technology Basis for BPT Effluent Limitations
Proposed Subpart
Name of Subcategory
Technology Basis
Metal-Bearing Waste
Treatment and
Recovery
Selective Metals Precipitation,
Pressure Filtration, Secondary
Precipitation, Solid-Liquid
Separation, and Tertiary
Precipitation
For Metal-Bearing Waste which
includes concentrated Cyanide
streams:
Pretreatment by Alkaline
Chlorination at specific operating
conditions
B
Oily Waste Treatment
and Recovery
Regulatory Option 1: Ultrafiltration
Regulatory Option 2:
Ultrafiltration, Carbon Adsorption,
and Reverse Osmosis
Organic Waste
Treatment and
Recovery
Equalization, Air Stripping,
Biological Treatment, and
Multimedia Filtration
ES-3
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Table ES-2. Cost of Implementing Regulations [in millions of 1993 dollars]
Subcategory
Metals Treatment and Recovery
Oils Treatment and Recovery -
Regulatory Option 1
Oils Treatment and Recovery -
Regulatory Option 2
Organics Treatment and Recovery
Regulatory Option 1
Regulatory Option 2
Number of
Facilities3
44
35
35
22
72
72
Capital
Costs
43.9
5.23
16.8
12.4
61.5
73.1
Annual O&M
Costs
33.5
3.15
29.7
4.5
41.2
67.7
The total number of facilities is less than the sum of the number of facilities in each
subcategory, because many facilities may operate in more than one subcategory.
EPA estimated the amount of pollutant reductions that would result for each of the
proposed technology options. Currently, 262.1 million pounds of pollutants are estimated
to be discharge directly and indirectly to POTWs. The proposed regulation would
decrease the amount of pollutants currently discharge by 129 millions pounds of pollutants
for Regulatory Option 1 and 146 million pounds for Regulatory Option 2.
ES-4
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SECTION 1
STATUTORY REQUIREMENTS
Effluent limitations guidelines and standards for the Centralized Waste Treatment
Industry are being proposed under the authority of Sections 301, 304, 306, 307, and 501
of the Clean Water Act (the Federal Water Pollution Control Act Amendments of 1972, 33
U.S.C. 1251 et seq., as amended by the Clean Water Act of 1977, Pub. L. 95-217, and the
Water Quality Act of 1987, Pub. L. 100-4), also referred to as "the Act."
1.1 LEGAL 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 is to issue
effluent limitations guidelines and standards for industrial discharges. These guidelines
and standards are summarized briefly in the following sections.
1.1.1 Best Practicable Control Technology Currently Available (BPT)
(Section 304(b)(1) of the CWA)
In the guidelines, EPA defines BPT effluent limits for conventional, priority, and
non-conventional pollutants. In specifying BPT, EPA looks at a number of factors. EPA
first considers the cost of achieving effluent reductions in relation to the effluent reduction
benefits. The Agency next considers: 1) the age of the equipment and facilities, the
processes employed and any required process changes, engineering aspects of the
control technologies, non-water quality environmental impacts (including energy
requirements), and such other factors as the Agency deems appropriate (CWA
§304(b)(1)(B)). Traditionally, EPA establishes BPT effluent limitations based on the
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average of the best performances of facilities within the industry of various ages, sizes,
processes or other common characteristics. Where, however, existing performance within
a category or subcategory is uniformly inadequate, EPA may require higher levels of
control than currently in place in an industrial category (or subcategory) if the Agency
determines that the technology can be practically applied. BPT may be transferred from
a different subcategory or category.
In the initial stages of EPA CWA regulation, EPA efforts emphasized the
achievement of BPT limitations for control of the "classical" pollutants (e.g., TSS, pH,
BODS). However, nothing on the face of the statute explicitly restricted BPT limitation to
such pollutants. Following passage of the Clean Water Act of 1977 with its requirement
for points sources to achieve best available technology limitations to control discharges
of toxic pollutants, EPA shifted its focus to address the listed priority pollutants under the
guidelines program. BPT guidelines continue to include limitations to address all
pollutants.
1.1.2 Best Conventional Pollutant Control Technology (BCT)
(Section 304(a)(4) of the CWA)
The 1977 Amendments added Section 301(b)(2)(E) to the Act establishing BCT for
discharges of conventional pollutants from existing industrial point sources. Section
304(a)(4) designated the following as conventional pollutants: Biochemical oxygen
demanding pollutants (BOD), total suspended solids,(TSS), fecal coliforrn, pH, and any
additional pollutants defined by the Administrator as conventional. The Administrator
designated oil and grease as an additional conventional pollutant on July 30, 1979 (44 FR
44501). BCT is not an additional limitation, but replaces BAT for the control of
conventional pollutants. In addition to other factors specified in Section 304(b)(4)(B), the
Act requires that BCT limitations be established in light of a two-part "cost-effectiveness"
test [American Paper Institute v. EPA, 660 F.2d 954 (4th Cir. 1981)]. EPA's current
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methodology for the general development of BCT limitations was issued in 1986 (51 FR
24974; July9, 1986).
1.1.3 Best Available Technology Economically Achievable (BAT)
(Sections 304(b)(2)(B) of the CWA)
In general, BAT effluent limitations guidelines represent the best economically
achievable performance of plants in the industrial subcategory or category. The CWA
establishes BAT as a principle means of controlling the direct discharge of priority and
non-conventional pollutants to waters of the United States. The factors considered in
assessing BAT include the cost of achieving BAT effluent reductions, the age of equipment
and facilities involved, the process employed, potential process changes, and non-water
quality environmental impacts, including energy requirements. The Agency retains
considerable discretion in assigning the weight to be accorded these factors. Unlike BPT
limitations, BAT limitations may be based on effluent reductions attainable through
changes in a facility's processes and operations. As with BPT, where existing performance
is uniformly inadequate, BAT may require a higher level of performance than is currently
being achieved based on technology transferred from a different subcategory or category.
BAT may be based upon process changes or internal controls, even when these
technologies are not common industry practice.
1.1.4 New Source Performance Standards (NSPS) (Section 306 of the CWA)
NSPS reflect effluent reductions that are achievable based on the best available
demonstrated treatment technology. New plants have the opportunity to install the best
and most efficient production processes and wastewater treatment technologies. As a
result, NSPS should represent, the most stringent controls attainable through the
application of the best available control technology for all pollutants (i.e., conventional,
nonconventional, and toxic pollutants). In establishing NSPS, EPA is directed to take into
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consideration the cost of achieving the effluent reduction and any non-water quality
environmental impacts and energy requirements.
1.1.5 Pretreatment Standards for Existing Sources (PSES)
(Section 307(b) of the CWA)
PSES are designed to prevent the discharge of pollutants that pass-through,
interfere-with, or are otherwise incompatible with the operation of publicly-owned treatment
works (POTW). The CWA authorizes EPA to establish pretreatmenl: standards for
pollutants that pass-through POTWs or interfere with treatment processes or sludge
disposal methods at POTWs. Pretreatment standards are technology-based and
analogous to BAT effluent limitations guidelines.
The General Pretreatment Regulations, which set forth the framework for the
implementation of categorical pretreatment standards, are found in 40 CFR Part 403.
Those regulations contain a definition of pass-through that addresses localized rather than
national instances of pass-through and establishes pretreatment standards that apply to
all non-domestic dischargers (52 FR 1586).
1.1.6 Pretreatment Standards for New Sources (PSNS) (Section 307(b) of the CWA)
Like PSES, PSNS are designed to prevent the discharges of pollutants that pass-
through, interfere-with, or are otherwise incompatible with the operation of POTWs. PSNS
are to be issued at the same time as NSPS. New indirect dischargers have the opportunity
to incorporate into their plants the best available demonstrated technologies. The Agency
considers the same factors in promulgating PSNS as it considers in promulgating NSPS.
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1.2 SECTION 304(M) REQUIREMENTS AND LITIGATION
Section 304(m) of the Clean Water Act (33 U.S.C. 1314(m)), added by the Water
Quality Act of 1987, requires EPA to establish schedules for (I) reviewing and revising
existing effluent limitations guidelines and standards ("effluent guidelines"), and (ii)
promulgating new effluent guidelines. On January 2, 1990, EPA established an Effluent
Guidelines Plan (55 FR 80), in which schedules were established for developing new and
revised effluent guidelines for several industrial categories. One of the industries for which
the Agency established a schedule was the Waste Treatment Industry Phase I -
Centralized Waste Treatment.
Natural Resources Defense Council, Inc. (NRDC) and Public Citizen, Inc.
challenged the Effluent Guidelines Plan in a suit filed in U.S. District Court for the District
of Columbia (NRDC et al v. Reilly, Civ. No. 89-2980). The plaintiffs charged that EPA's
plan did not meet the requirements of Section 304(m). A Consent Decree in this litigation
was entered by the Court on January 31, 1992. The Decree requires, among other things,
that EPA propose effluent guidelines for the subcategories of the Centralized Waste
Treatment Industry by April 1994, and take final action by January 1996. In March 1994,
due to project delays, an unopposed motion was filed to the court to extend the proposal
until December 1994 and promulgation until September 1996.
1-5
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SECTION 2
DATA COLLECTION
EPA has gathered and evaluated technical and economic data from various sources
in the course of developing the effluent limitations guidelines and standards for the
Centralized Waste Treatment Industry. These data sources include:
Responses to EPA's "1991 Waste Treatment Industry Questionnaire,"
Responses to EPA's "Detailed Monitoring Questionnaire,"
EPA's 1990 - 1994 sampling of selected Centralized Waste Treatment
facilities,
• Literature data, and
Other EPA studies of Treatment, Storage, Disposal, and Recycling facilities.
EPA has used data from these sources to profile the industry with respect to:
wastes received for treatment or recovery, treatment/recovery processes, geographical
distribution, and wastewater and solid waste disposal practices. EPA then characterized
the wastewater generated by treatment/recovery operations through an evaluation of water
usage, type of discharge or disposal, and the occurrence of conventional, non-
conventional, and priority pollutants.
2.1 CLEAN WATER ACT SECTION 308 QUESTIONNAIRES
2.1.1 Development of Questionnaires
A major source of information and data used in developing effluent limitations
guidelines and standards is industry responses to questionnaires distributed by EPA under
the Authority of Section 308 of the Clean Water Act. These questionnaires typically
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request information concerning treatment processes, wastes received for treatment, and
disposal practices as well as wastewater treatment system performance data.
Questionnaires also request financial and economic data for use in assessing economic
impacts and the economic achievability of technology options.
EPA used its experience with previous questionnaires to develop two
questionnaires (the 1991 Waste Treatment Industry Questionnaire and the Detailed
Monitoring Questionnaire) for this study. The 1991 Waste Treatment Industry
Questionnaire was designed to request 1989 technical, economic, and financial data to
describe industrial operations adequately from a census of the industry. The Detailed
Monitoring Questionnaire was designed to elicit daily analytical data from a limited number
of facilities which would be chosen after receipt and review of the 1991 Waste Treatment
Industry Questionnaire responses.
For the 1991 Waste Treatment Industry Questionnaire, EPA wanted to minimize the
burden to Centralized Waste Treatment facilities because these facilities are also required
to complete extensive paperwork under the Resource Conservation and Recovery Act.
A questionnaire was developed for which recipients could use information reported in their
1989 Hazardous Waste Biennial Report to complete specific tables as well as any other
readily accessible data. The questionnaire specifically requested information on:
• treatment/recovery processes,
• types of waste received for treatment,
• wastewater and solid waste disposal practices,
ancillary waste management operations,
• summary analytical monitoring data,
the degree of co-treatment (treatment of waste received from off-site with
other on-site industrial waste),
• cost of waste treatment/recovery processes, and
the extent of wastewater recycling or reuse at facilities.
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In the 1991 Waste Treatment Industry Questionnaire, EPA requested summary
monitoring data from all recipients, but summary information is not sufficient for
determining limitations and industry variability. Therefore, the Detailed Monitoring
Questionnaire was designed to collect daily analytical data from a limited number of
facilities. Facilities would be chosen to complete the Detailed Monitoring Questionnaire
based on technical information submitted in the 1991 Waste Treatment Industry
Questionnaire, such as on-site treatment technologies, types of waste accepted for
treatment, and present permit limitations. The burden was also minimized in the Detailed
Monitoring Questionnaire by tailoring the questionnaire to the facility operations.
Due to the lack of monitoring data on the wastewater treatment system influent,
waste receipt data for a six-week period was also requested in the Detailed Monitoring
Questionnaire. Waste receipt data are forms containing information on specific shipments
of waste. A limit of six weeks was placed on this request to minimize the burden to
facilities responding as well as to request a manageable set of data.
EPA sent draft questionnaires to industry trade associations, treatment facilities who
had expressed interest, and environmental groups for review and comment. A pre-test of
the 1991 Waste Treatment Industry Questionnaire was also conducted at nine Centralized
Waste Treatment facilities to determine if the type of information necessary would be
received from the questions posed as well as to determine if questions were designed to
minimize the burden to facilities. A pre-test of the Detailed Monitoring Questionnaire was
not possible due to project schedule limitations.
Based on comments from the reviewers, EPA determined the draft questionnaire
required minor adjustments in the technical section, but extensive revisions were required
for the economic and financial section. These revisions were required because this data
collection effort was the first attempt at requesting information from a service industry as
opposed to a manufacturing-based industry.
As required by the Paperwork Reduction Act, 44 U.S.C. 3501 et seq., EPA
submitted the questionnaire package (including the revised 1991 Waste Treatment
Industry Questionnaire and the Detailed Monitoring Questionnaire) to the Office of
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Management and Budget (OMB) for review, and published a notice in the Federal Register
to announce the questionnaire was available for review and comment (55 FR 45161). EPA
also redistributed the questionnaire package to industry trade associations, Centralized
Waste Treatment Industry facilities, and environmental groups that had provided
comments on the previous draft and to any others who requested a copy of the
questionnaire package.
No additional comments were received. In fact, one industry trade association
submitted comments to OMB in favor of the questionnaire and requested OMB's immediate
clearance. OMB cleared the entire questionnaire package for distribution on April 10,
1991.
2.1.2 Distribution of Questionnaires
EPA identified 455 facilities as possible Centralized Waste Treatment facilities from
various sources, such as the respondent list to the Survey of Treatment, Storage,
Disposal, and Recycling Facilities, companies listed in the Environmental Information (El)
Directory, companies listed in major city telephone directories under environmental
services, and facilities listed in the Toxic Release Inventory (TRI) data which receive waste
from off-site.
Under the authority of Section 308 of the Act, EPA distributed the 1991 Waste
Treatment Industry Questionnaire to all 455 facilities in the EPA facility database. EPA
received responses from 413 facilities (a 91 % response rate). In general, after review of
the responses, EPA concluded that 326 facilities were not in the scope of the proposed
regulation either because they were closed or the facility did not meet the profile of a CWT
facility. The responses indicated that 89 respondents received waste from off-site for
treatment or recovery. Four of the 89 received waste via a conduit (e.g., pipeline,
trenches, or ditches) from the original source of waste generation and are not covered
under the proposed regulation. Therefore, 85 facilities were identified as being in the
Centralized Waste Treatment Industry.
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In addition to information obtained through the 1991 Waste Treatment Industry
Questionnaire, information was also obtained through follow-up phone calls and written
requests for clarification of questionnaire responses.
After receipt of 1991 Waste Treatment Industry Questionnaire responses,
information was reviewed and nineteen facilities were chosen to complete the Detailed
Monitoring Questionnaire based on: types and quantities of wastes received for treatment;
quantity of on-site generated wastewater not resulting from treatment or recovery of off-site
generated waste; treatment/recovery technologies operated; wastewater discharge
options; and present wastewater permit limitations.
2.2 SAMPLING PROGRAM
2.2.1 Pre-1989 Sampling Program
From 1986 to 1987, twelve facilities were sampled to characterize the waste
streams and on-site treatment technology performance at hazardous waste incinerators,
Subtitle C and D landfills, and facilities which receive waste from off-site for treatment as
a part of the Hazardous Waste Treatment Industry Study. All of the facilities in this
sampling program had multiple operations, such as incineration and commercial
wastewater treatment. The sampling program did not focus on characterizing the
individual waste streams from different operations. Therefore, the data collected cannot
be used for the characterization of Centralized Waste Treatment wastewater, assessment
of treatment performance, or the development of limitations and standards. Information
collected in the study is presented in the Preliminary Data Summary for the Hazardous
Waste Treatment Industry (EPA 440/1 -89/100).
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2.2.2
1989 - 1993 Sampling Program
2.2.2.1
Facility Selection
Between 1989 and 1993, EPA visited 26 of the 85 centralized waste treatment
facilities. During each visit, EPA gathered the following information:
the process for accepting waste for treatment or recovery,
the types of waste accepted for treatment,
design and operating procedures for treatment technologies,
• general facility management practices,
wastewater discharge options,
solid waste disposal practices, and
• other facility operations.
After reviewing the information received during facility site visits, the EPA chose the
facilities to be sampled by assessing whether the wastewater treatment system (1) was
effective in removing pollutants; (2) treated wastes received from a variety of sources, (3)
employed either novel treatment technologies or applied traditional treatment technologies
in a novel manner, and (4) applied waste management practices that increased the
effectiveness of the treatment unit.
The EPA also needed to determine if the CWT portion of the facility flow was
adequate to assess the treatment system performance for CWT waste streams. For many
facilities, the CWT operations were minor portions of the overall site operation. In such
cases, when the CWT waste stream is commingled prior to treatment, characterizing the
CWT waste stream and assessing the treatment performance in respect to a CWT waste
stream would be difficult and therefore could not be used to establish effluent limitations
guidelines and standards for the Centralized Waste Treatment Industry.
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Another important aspect, when selecting facilities for the sampling program was
the quantity of non-CWT wastewater treatment with CWT wastewater. For example, many
facilities treated metal-bearing and oily waste in the same treatment system. The EPA
needed to assess if these pollutants were being removed when these waste streams were
treated in the same treatment system or if dilution was occurring.
Based on information received during the visits and responses to the 1991 Waste
Treatment Industry Questionnaire, EPA selected eight of the 26 facilities to be included
in the wastewater sampling program for establishing limitations and standards. An
additional facility was sampled to characterize the wastes received and treatment
processes of a facility that treated only non-hazardous waste. The other 17 facilities
visited were not sampled, because they did not meet the criteria listed above.
Based on information received, EPA chose six facilities to be sampled to assess the
performance at facilities which treated metal-bearing waste. All of the facilities visited
used metals precipitation as a means for treatment, but each of the systems was unique
due to the chemicals used and actual treatment set-up. Most facilities precipitated metals
in batches. Similar waste receipts were mixed and the metals were precipitated in a one
step process. One facility separated each waste shipment into separate treatment tanks
to facilitate the precipitation of specific metals and then transferred the batch to another
tank to precipitate additional metals. Another facility had a continuous system for
precipitation: whereas, the wastewater flowed from one treatment chamber to another and
in each chamber different chemicals were used.
For oily wastes, three facilities were sampled to characterize the waste streams and
assess the treatment performance. All three facilities used chemical emulsion-breaking
processes to initially separate oil-water mixtures. For two of the three facilities, the
wastewater from emulsion-breaking was commingled with metal-bearing CWT wastewater
prior to further treatment. One facility treated the wastewater from emulsion-breaking in
a system specifically designed to treat oily wastes and the oily wastewater was not
commingled with other waste streams. No other facilities were identified for sampling
because most of the facilities accepted other types of waste for treatment and did not
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operate treatment systems specifically designed for treatment of oily wastes as in the case
with two of the facilities sampled.
Two organic waste treatment facilities were sampled to characterize the waste
streams and assess treatment performance. One facility treated the organic waste stream
by the following sequence of treatment technologies; two air-strippers in series equipped
with air pollution control devices, biological treatment in a Sequential Batch Reactor,
multimedia filtration, and final polishing by carbon adsorption units. The other facility
utilized a patented CO2 extraction process to recover organic compounds for use as fuel
and treated the resulting wastewater via carbon adsorption. No further facilities were
identified for sampling because most of the facilities treating organic waste have other
industrial operations and the portion of CWT waste was minor in comparison to the overall
facility flow.
2.2.2.2
Sampling Episodes
After a facility was chosen to participate in the sampling program, a draft sampling
plan was prepared which described the location of sample points and analysis to be
performed at specific sample points as well as the procedures to be followed during the
sampling episode. Prior to sampling, a copy of the draft sampling plan was provided to the
facility for review and comment to ensure the EPA properly described and understood
facility operations. All comments were incorporated into the final sampling plan. During
the sampling episode, teams of EPA employees and contractors collected and preserved
samples. Samples were sent to EPA approved laboratories for analysis. Samples were
collected at influent, intermediate, and effluent points. Facilities were given the option to
split samples with the EPA, but most facilities declined. Following the sampling episode,
a draft sampling report was prepared that included descriptions of the treatment/recovery
processes, sampling procedures, and analytical results. After all information was
gathered, the reports were provided to facilities for review and comment. Corrections were
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incorporated into the final report. The facilities also identified any information in the draft
sampling report that were to be considered Confidential Business Information.
At the initial two sampling episodes, the entire spectrum of chemical compounds for
which there are EPA-approved analytical methods were analyzed (more than 480
compounds). All compounds were analyzed because no data was received from facilities
to narrow the list of analytes. After a review of initial analytical data, the number of
constituents analyzed was decreased to 320 by omitting analysis for dioxins/furans,
pesticides/herbicides, methanol, ethanol, and formaldehyde. Pesticides/herbicides were
analyzed on a limited basis depending on the treatment chemicals used at facilities.
Dioxin/furan analysis was performed on a limited basis for solid/filter cake samples to
assess possible environmental impacts.
Data was collected for a variety of treatment systems handling a variety of wastes.
Information on the waste stream characteristics is included in Section 4 and treatment
system performance is included in Section 6.
2.2.3 1994 Sampling Program
In 1994, an additional four facilities were visited to identify the types of waste
presently being accepted at oily waste treatment facilities. These facilities were not in
operation at the time the questionnaire was mailed, and they specialize in the treatment
of bilge waters and unstable oil-water mixtures. In the 1989 -1993 sampling program, oily
waste treatment facilities were characterized as treating concentrated, stable oil-water
emulsions. According to information received from permit writers, the industry trend has
been in the area of bilge water treatment. From these site visits, one facility was chosen
to be sampled based on the on-site treatment and type of oily waste accepted for
treatment. At the time of proposal, the analytical data could not be reviewed, but are
included in the regulatory record. The information collected will be used for re-evaluating
EPA's characterization of the oily wastes accepted for treatment. EPA will re-assess the
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pollutant concentrations detected at oily waste treatment facilities as well as evaluate
additional treatment technologies.
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SECTION 3
DESCRIPTION OF THE INDUSTRY
Development of a Centralized Waste Treatment Industry is a probable outgrowth
of the increased pollution control measures required by CWA and RCRA requirements.
In order to comply with CWA discharge limits, industries covered by categorical regulations
installed new (or upgraded existing) wastewater treatment facilities in order to treat their
process wastewater. But the wastewater treatment produced a residual sludge which
required further treatment before disposal under RCRA requirements. Furthermore, many
industrial process by-products were now, for regulatory purposes, classified as either
RCRA listed or characteristic hazardous wastes which required special handling or
treatment before disposal. Therefore, a market for waste management was developed due
to the demand of waste management services.
In the early 1990's, this industry experienced a slow down because many existing
facilities were designed to handle larger quantities of wastes than the market produced.
Generally, reduced economic activity, in combination with pollution prevention measures,
resulted in a decrease in the amount of waste sent off-site for treatment. Also, the
available capacity in the industry reflected industry anticipation that upcoming
environmental regulations would be increasingly stringent and thereby increase the
demand for waste management services. As a result, when demand failed to materialize
as expected, competition among facilities increased. This resulted in facilities operating
below capacity and experiencing economic and financial difficulties. This trend may be
changing at the present. Recently, participants in the March 1994 public meeting for this
proposal stated that the industry is experiencing new growth due to increasing
environmental regulations.
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3.1 GENERAL INFORMATION
In 1989, EPA identified 85 facilities that accept by any form of shipment hazardous
or non-hazardous industrial waste from off-site for treatment or recovery. The distribution
of the 85 Centralized Waste Treatment facilities in the United States is pressented in Figure
3-1. Most facilities are located in the eastern half of the United States with the highest
concentration in the Mid-West. Many facilities are located close to large industrial areas
to facilitate the transfer of waste from manufacturing facilities.
Most facilities receive waste via tanker truck. However, other forms of shipment are
used for transporting wastes, such as trailers/roll-off boxes, drums, and barges. In the
data collection, EPA identified four facilities which were receiving all of the waste from off-
site via a pipeline. In evaluating the operations and waste accepted at such facilities, EPA
determined that their operation was not similar to a facility which received waste by other
Figure 3-1. Distribution of Centralized Waste Treatment Facilities
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forms of shipment and therefore would not be included in the scope of the proposed
effluent limitations guidelines and standards.
The wastes sent by way of a conduit (i.e., pipeline, trenches, ditches, etc.) for
treatment were characterized as process wastewater from existing categorical industries,
not concentrated, difficult-to-treat wastes. Therefore, Best Professional Judgment (BPJ)
discharge permits for facilities accepting waste via a conduit should be developed using
the categorical standards from the industries which are sending the waste.
Many facilities have other industrial operations on-site in addition to a Centralized
Waste Treatment facility. These industrial processes include other waste management
operations (i.e., landfills, incinerators, solidification or fuel blending processes, etc.) or
manufacturing operations. Approximately, 14 facilities are manufacturers of products. The
most common manufacturing industries represented are organic chemicals and inorganic
chemicals. The effect of the addition of other industrial wastewater is only discussed if the
other industrial wastewater is co-treated with Centralized Waste Treatment wastewater.
For these types of facilities, in general, CWT wastewater accounts for only 7% of the
overall facility flow.
Some information normally used to describe an industry was not available for this
study. For example, U.S. Department of Commerce, Bureau of the Census Standard
Industrial Classification (SIC) codes are typically used by industries to describe a facility
operation. No SIC codes exist for the Centralized Waste Treatment Industry. Some
facilities have chosen 4959 as the SIC code, Sanitary Services, Not Elsewhere Classified.
This classification, however, actually pertains to services such as beach maintenance, oil
spill clean-up, snowplowing, etc.
3.2 WASTES RECEIPTS
As previously explained, EPA also collected various information was collected
pertaining to the types of waste accepted for treatment. Seventy-two out of the 85
Centralized Waste Treatment facilities are RCRA-permitted treatment, storage, and
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disposal facilities (TSDFs). Therefore, a majority of facilities was able to use information
reported in the 1989 Biennial Hazardous Waste Report to classify the wastes accepted for
treatment by the appropriate RCRA and Waste Form Codes.
Most of the waste treated at Centralized Waste Treatment facilities is characterized
as highly-concentrated and consequently difficult-to-treat. The concentration of pollutants
detected in the raw wastewater was the highest detected in existing categorical
regulations.
3.2.1 Waste Receipt Types
Facilities received a wide variety of hazardous and non-hazardous industrial waste
for treatment in the Centralized Waste Treatment Industry. For hazardous wastes, RCRA
Codes are often used to categorize wastes. The RCRA codes reported in the 1991 Waste
Treatment Industry Questionnaire are listed in Table 3-1. Most of the RCRA codes do not
contain information regarding the waste characteristics such as chemical constituent or
concentration of chemical constituents.
Table 3-1. RCRA Codes Reported by Facilities in 1989.
RCRA Codes
D001
D002
D003
D004
D005
D006
D007
D008
D009
D010
D011
D012
D017
D035
F001
F002
F003
F004
F005
F006
FOOT
F008
F009
F010
F011
F012
F019
F039
K001
K011
K013
K014
K015
K016
K031
K035
K044
K045
K048
K049
K050
K051
K052
K061
K063
K064
K086
K093
K094
K098
K103
K104
P011
P012
P013
P020
P022
P028
P029
P030
P040
P044
P048
P050
P063
P064
P069
P071
P074
P078
P087
P089
P098
P104
P106
P121
P123
U002
U003
U008
U009
U012
U013
U019
U020
U031
U044
U045
U052
U054
U057
U069
U080
U092
U098
U105
U106
U107
U113
U118
U122
U125
U134
U135
U139
U140
1)150
U151
U154
U159
U161
U162
U188
U190
U205
U210
U213
U220
U226
U228
U239
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In the Hazardous Waste Biennial Report, Waste Form Codes are used to further
characterize the wastes received for treatment. The Waste Form Codes reported by
Centralized Waste Treatment facilities are listed in Table 3-2% Definitions of the RCRA
Codes and Waste Form Codes are listed in Appendix A. Some facilities, especially those
that treat non-hazardous waste, did not report the Waste Form Code information due to
the variety and complexity of their operations.
Table 3-2. Waste Form Codes Reported by Facilities in 1989.
Waste Form
B001
B101
B102
B103
B104
B105
B106
B107
B108
B109
B110
B111
B112
B113
B114
B115
B1.16
B117
B119
B201
B202
B203
B204
B205
B206
B207
B208
B209
B210
B211
B219
B305
B306
B307
B308
B309
Codes
B310
B312
B313
B315
B316
B319
B501
B502
B504
B505
B506
B507
B508
B510
B511
B513
B515
B518
B519
B601
B603
B604
B605
B607
B608
B609
In Table 3-3, information on the quantity of hazardous and non-hazardous industrial
waste received for treatment or recovery is compiled. Many facilities which are permitted
to accept hazardous wastes also treat or recover a large quantity of non-hazardous
wastes. For purposes of the proposed effluent limitations guidelines and standards,
"hazardous wastes" are those defined by RCRA as hazardous. State-defined hazardous
wastes, such as waste oils, are classified as non-hazardous for the purposes of this study.
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Table 3-3. Quantity of Waste Received for Treatment
Type of Waste
Hazardous
Non-Hazardous
Quantity of Waste (gal/yr)
Total
506,415,098
384,316,949
Average
8,052,183
12,974,482
Minimum
1,200
5,825
Maximum
85,200,000
232,599,789
An additional potential source of information on the characterization of the wastes
treated at a CWT operation is descriptive data from the generator of a v/aste. However,
most CWT facilities did not collect information on the process for which the waste was
generated. In general, based on information collected for these guidelines and standards,
the most common forms of waste receipts were sludges from tank bottoms or treatment
processes, rinse water from cleaning operations, and soil and wastewater from remediation
activities.
3.2.2 Procedures for Receipt of Wastes
In the process of gathering information, the procedures for accepting a waste for
treatment or recovery were studied. The same general procedure is used for most
facilities. The process is outlined in Figure 3-2.
In general, facilities require the waste generator to provide extensive paper work
on the waste, such as analytical data, descriptive characteristics and chain of custody
reports. Generators must also supply a sample of the waste stream to be treated with
corresponding laboratory analysis. Then, the Centralized Waste Treatment facility
performs further analysis and bench-scale treatability studies to determine if the waste can
be handled in their treatment/recovery system. If the facility determines it can handle the
waste, a price for the treatment of the given sample is established. After a price for
treatment is established, the generator may then begin to transport the approved waste
stream to the treatment facility.
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Sample of Waste
Sent to Facility
Waste Profile and
Bench Scale
Treatability Tests
are Performed
Treatment Scheme
is Developed
Cost for Treatment
is Determined
Company Makes Decision
on Treatmentof Waste
Waste is Shipped
to Facility for Treatment
Shipment is Analyzed to
Determine if Waste
Matches Initial Sample
Figure 3-2. Waste Receipt Procedures
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Upon receipt of the waste shipment, a sample is taken for analysis. The analysis
is compared to the original sample. If the analysis matches, the shipment is approved for
treatment. If the analysis does not match, a new price for treatment may be determined
or the shipment may be refused for treatment.
3.3 DISCHARGE INFORMATION
In general, three basic options are available for disposal of wastewater treatment
effluent: direct, indirect, and zero( or alternative) discharge. Direct dischargers are
facilities that discharge effluent directly into a surface water. Indirect dischargers are
facilities which discharge effluent to a publicly-owned treatment works (POTW). Zero or
alternative dischargers do not generate a wastewater nor do they discharge to a surface
water or POTW. The types of zero or alternative discharge identified as employed in the
Centralized Waste Treatment Industry are underground injection control (UIC), off-site
transfer for further treatment, and evaporation. Table 3-4 lists the number of dischargers
for each discharge option.
Table 3-4. Distribution of Facility Discharge
Discharge Option
Direct
Indirect
Direct and UIC
UIC
Off-Site
Evaporate
No Wastewater Generated
No. of Facilities
15
56
1
4
6
2
1
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In 1989, more than 3.0 billion gallons of wastewater were generated for disposal.
Average facility information is presented in Table 3-5 for each discharge option. The
proposed effluent limitations guidelines and standards for the Centralized Waste
Treatment Industry do not apply to facilities with a zero or alternative discharge.
Table 3-5. Quantity of Wastewater Discharged in 1989
Discharge
Option
Direct
Indirect
UIC
Off-Site
Evaporate
Quantity Discharged in 1989 (gal)
Total
2,314,110,276
702,286,054
119,737,220
2,498,944
1,728,213
Average
144,631,892
12,540,822
24,912,424
416,491
864,106
Minimum
20,605
2,718
4,736,000
9,112
730,000
Maximum
1,169,975,506
155,655,000
51,529,663
1,408,810
998,213
3.4 TREATMENT RESIDUALS
Various types of residuals were generated from the treatment or recovery
processes. In 1989, more than 1.1 billion pounds of treatment residuals were generated.
Information on the quantity of treatment residuals and disposal practices by facilities is
presented in Table 3-6. The disposal practice used depends on the residual content.
Metal-bearing residuals are most predominately disposed in Subtitle C or D landfills. The
regulatory classification of the landfill used is dependent on the quantity of metals present
in the residual and their ability to leach from the residual. Oily treatment residuals are
typically reused for fuel in on-site or off-site operations. Organic residuals are usually sent
to incinerators for disposal.
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Table 3-6. Quantity of Treatment Residuals in 1989
Disposal Practice
Subtitle C Landfill
(33)
Subtitle D Landfill
(31)
Land Application
(2)
Hauled Off-Site
(16)
Recycled Off-Site
(17)
Incineration
(10)
Sold as Product
(4)
Quantity of Treatment Residual in 1989 (Ibs)
Total
2,582,347,377
684,071,793
15,800
163,014,881
816,971,414
5,754,400
59,796,396
Average
- 7,646,890
22,147,611
7,900
10,188,430
48,057,142
575,440
14,949,099
Minimum
75
9
5,780
5,984
300
548
332,000
Maximum
80,053,988
135,142,804
10,020
103,025,422
791,096,475
3,532,314
49,668,281
Note: The number of facilities using each disposal practice is listed in parentheses.
3.5 INDUSTRY SUBCATEGORIZATION
Division of a point source category into groupings entitled "subcategories" provides
a mechanism for addressing variations between products, raw materials, processes, and
other parameters which result in distinctly different effluent characteristics. Regulation of
a category by subcategory provides that each has a uniform set of effluent limitations
which take into account technology achievability and economic impacts unique to that
subcategory.
The factors considered in the subcategorization of the Centralized Waste Treatment
Point Source Category include:
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Type of waste received for treatment,
Treatment process,
Nature of wastewater generated,
Facility size,
Facility age,
Facility location,
Non-water quality impact characteristics, and
Treatment technologies and costs.
EPA evaluated these factors and determined that subcategorization is appropriate
for this industry. These evaluations are discussed in detail in the following section.
3.5.1 Development of Subcategorization Scheme
In establishing the subcategories set forth in this rulemaking, EPA took into account
all information it was able to collect and develop with respect to the following factors:
waste type received; treatment process; nature of wastewater generated; dominant waste
streams; facility size, age, and location; non-water quality impact characteristics; and
treatment technologies and costs.
In this industry, a wide variety of wastes are treated at a typical facility. Facilities
employ different waste treatment technologies tailored to the specific type of waste being
treated in a given day. The operation of a facility changes daily depending on the type of
waste accepted for treatment. Due to changing markets facilities may change the facility
operation frequently. Therefore, many of the traditional subcategorization bases for
facilities manufacturing products on a consistent basis are not applicable to this industry.
EPA concluded a number of factors did not provide an appropriate basis for
subcategorization, because the industry must change to meet the market and regulatory
demands. The Agency concluded that the age of a facility should not be a basis for
subcategorization because many older facilities have unilaterally improved or modified
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their treatment process over time. Facility size is also not a useful basis for
subcategorization for the Centralized Waste Treatment Industry because there is only
limited scale economics associated with waste treatment. Wastes can be treated to the
same level regardless of the facility size., Likewise, facility location is not a good basis for
subcategorization; no consistent differences in wastewater treatment performance or costs
exist because of geographical location. Although non-water quality characteristics (solid
waste and air emission effects) are of concern to EPA, these characteristics did not
constitute a basis for subcategorization. Environmental impacts from solid waste disposal
and from the transport of potentially hazardous wastewater are a result of individual facility
practices and EPA could not identify practices that apply uniformly across different
segments of the industry. Treatment costs do not appear to be a basis for
subcategorization because costs will vary and are dependent on the waste stream
variables such as flow rates, wastewater quality, and pollutant loadings. Therefore,
treatment costs were not used as a factor in determining subcategories.
EPA identified only one factor with primary significance for subcategorizing the
Centralized Waste Treatment Industry: type of waste received for treatment or recovery.
This factor encompasses many of the other subcategorization factors. The type of
treatment processes used, nature of wastewater generated, solids generated, and air
emissions directly correlate to the type of waste received for treatment or recovery.
Therefore, the type of waste received for treatment or recovery was determined to be the
appropriate basis for subcategorization of this industry.
3.5.2 Proposed Subcategories
Based on the type of wastes accepted for treatment or recovery, EPA has defined
three subcategories for the Centralized Waste Treatment Industry.
Subcategory A:
Operations which treat, or treat and recover metal from,
metal-bearing waste received from off-site,
3-12
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Subcategory B:
Subcategory C:
Operations which treat, or treat and recover oil from,
oily waste received from off-site, and
Operations which treat, or treat and recover organics
from, organic-bearing waste received from off-site.
3.5.2.1
Metal-Bearing Waste Treatment and Recovery Subcategory
This Subcategory applies to discharges resulting from the treatment or recovery of
metal-bearing waste. Currently, 56 facilities have been identified as treating metal-bearing
wastes in some cases for recovery of metals for sale in commerce or for return to industrial
processes. EPA proposes to regulate the conventional, priority, and non-conventional
pollutants in this Subcategory. This Subcategory also includes facilities which treat highly-
concentrated, complex cyanides.
3.5.2.2
Oily Waste Treatment and Recovery Subcategory
This subcategory applies to discharges resulting from the treatment or recovery of
oily waste. Currently, 35 facilities have been identified as treating and recovering oily
waste. EPA proposes to regulate conventional, priority, and non-conventional pollutants
in this subcategory. Most of the waste accepted for treatment and recovery in 1989 was
stable oil-water emulsions resulting from cleaning fluids and lubricants which are difficult
to treat. Other types of oily waste accepted for treatment include bilge waters and tank
cleaning wastewater.
3-13
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3.5.2.3
Organic Waste Treatment and Recovery Subcategory
This subcategory applies to discharges resulting from the treatment and recovery
of organic waste. Currently, 22 facilities operate organic waste treatment processes.
Organic recycling processes, such as solvent recycling, are not included in this regulation.
The wastes accepted for treatment in this subcategory are typically less concentrated than
the wastes treated in the other subcategories. Wastes from clean-up of groundwater and
landfill leachate are the most predominate source of wastewater. EPA proposes to
regulate the conventional, priority, and non-conventional pollutants in this subcategory.
3-14
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SECTION 4
WASTEWATER USE AND WASTEWATER CHARACTERIZATION
In 1991, under authority of Section 308 of the Clean Water Act, the Environmental
Protection Agency (EPA) distributed the "1991 Waste Treatment Industry Questionnaire,"
to 455 facilities that EPA had tentatively identified as possible Centralized Waste
Treatment facilities. Responses to the questionnaire indicated that 85 facilities received
hazardous and non-hazardous industrial waste from off-site for treatment or recovery via
any form of shipment in 1989. This section presents information on water use at these
facilities. This section also presents information on wastewater characteristics for the
Centralized Waste Treatment facilities that were sampled by EPA and for those facilities
that provided self-monitoring data.
4.1 WATER USE AND SOURCES OF WASTEWATER
The Centralized Waste Treatment Industry accepts for treatment large volumes of
waste and wastewater from off-site facilities. Water use and wastewater generation occur
at various points in a CWT facility's operations.
Wastewater treated at CWT facilities, as noted, includes off-site wastes and
wastewater from on-site operations. In general, the primary Centralized Waste Treatment
wastewater sources are: waste receipts, solubilization wastewater, tanker truck/drums/roll-
off box washes, equipment washes, air pollution control scrubber blow-down, laboratory-
derived wastewater, and contaminated stormwater. CWT facilities do not generate
"process wastewater" (Process wastewater is defined in 40 CFR 122.2 as "any water
which, during manufacturing or processing, comes into direct contact with or results from
the production or use of any raw material, by-product, intermediate product, finished
product, or waste product.") in the traditional sense. The term is used for manufacturing
or processing operations. Because the Centralized Waste Treatment Industry operations
do not include or result in "manufacturing processes" or "products," EPA refers to the
4-1
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wastewater treated in the Centralized Waste Treatment Industry by the terms "waste
receipts" for those wastes received from off-site for treatment and "CWT wastewater" for
the water which comes into contact with the waste received or waste processing or
handling areas as well as waste receipts.
Approximately 2.0 billion gallons of wastewater are generated annually by
Centralized Waste Treatment facilities. For most of the individual CWT wastewater
sources, it is difficult to determine specific quantities of each wastewater due to facilities
mixing the wastewater from different sources prior to treatment. The sources of CWT
wastewater are listed below.
Waste Receipts. Most of the waste received from customers comes in a
liquid form and constitutes a large portion of the wastewater treated at a
CWT facility. Other wastewater sources include wastewater from contact
with the waste at receipt or during subsequent handling.
• Solubilization Water. Some wastes are received in a solid form. Water may
be added to the waste to render it treatable.
Waste Oil Emulsion-Breaking Wastewater. The emulsion breaking process
separates difficult water-oil emulsions and generates a "bottom" or water
phase. Approximately 99.2 million gallons of wastewater were generated
from emulsion-breaking processes in 1989.
Tanker Truck/Drum/Roll-Off Box Washes. Water is used to clean the interior
and exterior of equipment used for transporting wastes. The amount of
wastewater generated was difficult to assess because the wash water is
normally added to the wastes or used as solubilization water.
4-2
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Equipment Washes. Water is used to clean waste treatment equipment
during unit shut downs or in between batches of waste.
Air Pollution Control Scrubber Blow-Down. Water or acidic or basic solution
is used in air emission control scrubbers to control fumes from treatment
tanks, storage tanks, and other process equipment. '
Laboratory-Derived Wastewater. Water is used in on-site laboratories which
characterize the incoming waste streams and monitor on-site treatment
performance.
Contaminated Stormwater. This is stormwater which comes in direct contact
with the waste.or waste handling and treatment areas.
The major volume of wastewater effluent discharged from the Centralized Waste
Treatment Industry is stormwater. Approximately 100 million gallons are discharged
annually. Stormwater may be contaminated by contact with receipts or the waste
processing area or it may be noncontaminated. Most of the wastewater monitoring data
submitted by facilities in the 1991 Waste Treatment Industry Questionnaire included
noncontaminated stormwater.
Many facilities also have other on-site industrial operations, i.e., organic
manufacturing. Waste streams from other industrial processes may be mixed with
Centralized Waste Treatment process wastewater prior to or after treatment. These other
industrial waste streams are not included as wastewater sources reviewed for effluent
limitations guidelines and standards for the Centralized Waste Treatment Industry. The
monitoring data received from facilities with other industrial waste streams were reviewed
to determine if the discharge streams for which data were submitted included other
industrial wastewater. In cases where the waste streams included other industrial waste,
the monitoring data were adjusted to remove the effect of the other industrial waste stream.
4-3
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4.2 WATER USE BY DISCHARGE
A summary of the CWT wastewater flow by type of discharge was presented in
Table 3-5 for the 85 CWT facilities. This information is based upon data collected in the
1991 Waste Treatment Industry Questionnaire. The discharge options are direct, indirect,
or zero discharge. '"Zero" discharge methods include no discharge, no wastewater
generation, land application, deep well injection, evaporation, and off-site disposal or
treatment. One facility discharges wastewater by direct discharge and deep well injection.
A large portion of wastewater discharges from the Centralized Waste Treatment
Industry is not generated by the CWT operations. As previously explained, facilities may
also have other industrial operations which generate non-CWT wastewater and that
wastewater may be treated with CWT waste streams. The quantity of non-CWT
wastewater, noncontaminated stormwater and other industrial waste streams, is
summarized in Table 4-1. Direct dischargers are the most affected by the addition of non-
CWT wastewater, because most of these facilities have other industrial operations.
Table 4-1. Comparison of total facility discharge to total CWT discharge.
Quantity Discharged
Total
Average
Minimum
Maximum
Total Facility Discharge
(gal/yr)
20,155,462,039
279,936,973
7,748
12,775,000,000
Total CWT Discharge
(gal/yr)
3,016,396,330
41,894,393
2,718
1,169,975,506
4-4
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4.3 WATER USE BY SUBCATEGORY
Off-site waste receipt quantities were used to estimate the quantity of wastewater
per subcategory. The quantity of waste receipts for each subcategory was calculated from
the estimate of waste received from off-site submitted for the 1991 Waste Treatment
Industry Questionnaire. As discussed in Section 4, waste receipts were divided into
subcategories by the waste form codes and RCRA codes.
Other sources of wastewater were apportioned to each subcategory by reviewing
treatment diagrams indicating the origination of the waste stream. In cases where CWT
wastewater could not be separated by subcategory, such as laboratory and truck rinsing
wastewater, the CWT wastewater was divided on the basis of the subcategory breakdown.
For example, the laboratory wastewater for a facility 70% in the Metals Subcategory and
30% in the Oils Subcategory was estimated to be 70% Metals Subcategory wastewater
and 30% Oil Subcategory wastewater.
Table 4-2 summarizes the amount of CWT and non-CWT wastewater by
subcategory. As previously discussed, many CWT facilities also have other industrial
operations. Wastewater from these other industrial operations on-site is commingled with
CWT wastewater prior to treatment. The amount of other industrial wastewater for each
subcategory is also presented in Table 4-2. As illustrated in Table 4-2, the Centralized
Waste Treatment wastewater for facilities in the Organics Subcategory is a minor portion
of the facility operation. Most Organics Subcategory facilities have other industrial
operations such as organics manufacturing. Facilities began accepting waste for
treatment because sufficient capacity existed in the treatment system.
4-5
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Table 4-2. Summary of Wastewater by Subcategory
Type of
Wastewater
Subcategory
Wastewater
Non-CWT
Wastewater
Number of
Facilities
Quantity of Wastewater (gal/yr)
Metal-bearing
Waste
Subcategory
41,795,489,977
19,131,768,908
56
Oily Waste
Subcategory
226,735,481
4,732,004,637
35
Organic Waste
Subcategory
1,359,815,755
19,220,128,314
21
4.4 WASTEWATER CHARACTERIZATION
A majority of the information reported in this section was collected from the EPA
Sampling Programs for the Centralized Waste Treatment Industry as discussed in
Section 3. Supplemental information was provided by self-monitoring data supplied in the
1991 Waste Treatment Industry Questionnaire, the Detailed Monitoring Questionnaire, and
the Waste Receipt information. The self-monitoring data were not used as extensively as
planned because many waste streams for which data were supplied included non-CWT
wastewater, and therefore, the data were not useful in properly characterizing Centralized
Waste Treatment operations. Also, the self-monitoring data were only available for a
limited number of pollutants in comparison to the scope of pollutants studied in the
Sampling Program.
The data presented in the following sections were collected at influent points to
treatment systems. The concentrations presented are lower than the original waste receipt
concentrations as a result of the commingling of a variety of waste streams. In most cases,
EPA could not collect samples from individual waste shipments because of physical
4-6
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constraints as well as the excessive analytical costs associated with the necessary
analysis.
4.4.1 Pollutant Parameters
Different pollutant parameters are used to characterize raw wastewater and
wastewater discharged by Centralized Waste Treatment facilities. These include:
Total Suspended Solids (TSS),
Biochemical Oxygen Demand (BOD5),
pH, and
Oil and Grease.
Total solids in wastewater is defined as the residue remaining upon evaporation at
just above the boiling point. Total suspended solids (TSS) is the portion of the total solids
that can be filtered out of the solution using a 1 micron filter. Raw wastewater TSS content
is a function of the type and form of waste accepted for treatment. (Typically, the higher
the TSS content the more concentrated the waste stream.) TSS can also be a function of
a number of other external factors, including stormwater runoff and runoff from storage
areas. The total solids are composed of matter which is settleable, in suspension, or in
solution and can be organic, inorganics, or a mixture of both. Settleable portions of the
suspended solids can be removed in a variety of ways, such as during the metals
precipitation process or by multimedia filtration, depending on a facility's operation. In the
Centralized Waste Treatment Industry, raw wastewater TSS is a function of the form in
which a waste is received for treatment, such as a solid or liquid. Wastewater that results
from the solubilization of solid waste receipts tends to have higher TSS values than waste
received in a liquid form. The highest TSS values detected in the Centralized Waste
Treatment Industry were found in the Metals Subcategory. Metal-bearing waste contain
high TSS levels, due to the industrial waste source as well as many waste receipts being
4-7
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accepted in solid form. A summary of the raw wastewater TSS levels is presented in
Table 4-3.
Table 4-3. Influent Concentrations Ranges for Selected Pollutant Parameters
Pollutant
Parameter
TSS
BOD*
Oil &_Grease
Influent Concentration Range (mg/l)
Metals
Subcategory
Min
86
4
3
Max
152,767
30,000
5995
Oils Subcategory
Min
190
4,520
49?
Max
22,258
10,067
180000
Organics
Subcategory
Min
44
4,100
16
Max
3,700
48,675
626
BOD5 is one of the most important gauges of pollution potential of a wastewater and
varies with the amount of biodegradable matter that can be assimilated by biological
organisms under aerobic conditions. The nature of chemicals discharged into wastewater
effects the BODS due to the differences in susceptibility of different molecular structures
to microbiological degradation. Compounds with lower susceptibility to decompose by
microorganisms tend to exhibit lower BOD5 values, even though the total organic loading
may be much higher than compounds exhibiting substantially higher BOD5 values.
The pH of a solution is a unitless measurement which represents the acidity or
alkalinity of a wastewater stream (or aqueous solution), based on the dissociation of the
acid or base in the solution into hydrogen (H+) or hydroxide (OH') ions, respectively. Raw
wastewater pH is a function of the source of waste receipts. This parameter can vary
widely from facility to facility and can be extremely variable in a single facility's raw
wastewater, depending on wastewater sources. Fluctuations in pH are readily reduced by
equalization followed by neutralization. Control of pH is necessary to achieve proper
removal of pollutants in treatment systems such as metals precipitation.
4-8
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Raw wastewater Oil and Grease is an important parameter in Centralized Waste
Treatment Industry wastewater, especially for the Oils Subcategory. Oil and Grease can
interfere with the operation of wastewater treatment plants and, if not removed prior to
discharge, can interfere with biological life streams and/or create films along surface
waters.
4.4.2 Priority and Non-Conventional Pollutants
As discussed previously, most of the data presented in this section was collected
during the EPA Sampling Program for the Centralized Waste Treatment Industry. The
pollutants detected at Centralized Waste Treatment facilities were dependent on the type
of waste accepted for treatment at a facility. The most predominant group of pollutants
detected was metals. Metals were detected in all samples collected. The concentration
of metals in raw wastewater was the highest found in industrial wastewater samples in
comparison to existing effluent limitations guidelines and standards. A summary of the
metal pollutants in raw wastewater by subcategory is presented in Table 4-4.
Organic pollutants were detected at varying amounts dependent on the subcategory
of the facility sampled. In the Metals subcategory, organic compounds were detected at
low levels since the organic compounds were incidental components of the waste receipts.
The type of organics detected at Oils and Organics Subcategory facilities varied
depending on the subcategory. Organic compounds in the Oils subcategory were more
petroleum-based, such as alkanes and glycols, than in the Organics Subcategory. A
summary of the organic pollutants in raw wastewater by subcategory is presented in
Table 4-5.
4-9
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Table 4-4. Range of Metal Pollutant Influent Concentrations (mg/l)
Pollutant
Aluminum
Antimony
Arsenic
Barium
Boron
Cadmium
Chromium - Hexavalent
Chromium -Total
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Phosphorus
Potassium
Selenium
Silicon
Silver
Sulfur
Tin
Titanium
Vanadium
Zinc
Metals Subcategory
Win
2.867
0.015
0.030
0.016
3.123
0.019
0.011
0.102
0.064
0.199
4.450
0.208
3.210
0.067
0.001
0.120
0.581
5.931
147.1
0.014
1.990
0.076
708.55
0.145
0.020
0.086
0.600
Max
2,090
1,160
25.961
27.709
1,420
307
40,000
16,300
232
21,000
3,745
4,390
1,360
102.63
3.100
849
1,700
456
8,895
1.520
1,330
6.060
24,100
15,100
7,500
264
7,735
Oils Subcategory
Min
1.200
0.027
0.059
0.398
31.363
0.038
0.363
0.551
1.200
43.60
0.607
22.40
1
0.5
0.733
0.313
0.011
0.033
0.592
0.264
10.349
Max
192.58
0.242
0.487
7.049
1,710
0.498
7.178
0.868
80.482
567.69
21.725
247.12
20.386
0.007
12.400
62.824
0.029
7.740
6.216
1.407
94.543
Organics Subcategory
Min
1.498
0.066
0.047
0.009
3.070
0.009
0.063
0.026
0.224
2.360
0.094
6.310
0.179
0.001
0.290
0.069
3
1,010
1.550
972
0.200
0.020
0.516
Max
157.94
1.540
0.634
2.190
103.33
0.049
1.265
0.731
2.690
88.828
0.687
23.800
1.513
0.007
6.950
2.610
15.900
1,240
3.600
1,990
2.530
20.559
2.352
4-10
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Table 4-5. Range of Organic Pollutant Influent Concentrations (mg/l)
Pollutant
1 ,1 ,1 ,2-Tetrachloroethane
1 ,1 ,1-Trichloroethane
1 ,1 ,2-Trichloroethane
1 ,1-Dichloroethane
1 ,1 -Dichloroethene
1 ,2.3-Trichloropropane
1 ,2-Dibromoethane
1 ,2-Dichloroethane
2,3,4,6-Tetrachlorophenol
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
2-Butanone
2-Picoline
2-Propanone
4-Chloro-3-Methylphenol
4-Methyl-2-Pentanone
Acetophenone
Benzene
Benzoic acid
Benzvl alcohol
Bromodichloromethane
Carbon disulfide
Chlorobenzene
Chloroform
Diethvl Ether
Diphenyl Ether
Ethvl Benzene
Metals Subcategory
Min
0.066
0.010
0.410
0.065
0.105
1.880
0.281
0.014
0.193
0.012
0.556
Max
0.628
0.043
2.879
8.135
64.797
13.947
5.568
0.111
39.281
0.337
1.394
Oils Subcategory
Min
0.111
0.057
2.395
4.148
0.070
5.450
0.057
Max
14.455
178.75
2,099.3
83.825
20.425
32.158
18.579
Organics Subcategory
Min
0.249
0.181
0.776
0.070
0.112
0.100
3.081
1.394
1.189
0.114
0.148
1.731
0.054
2.977
0.893
0.336
0.097
3.008
2.022
0.026
0.070
2.819
0.182
0.016
Max
0.644
3.195
1.859
0.108
0.118
0.220
6.094
10.681
1.734
0.226
0.203
322.89
0.125
447,722.0
4.038
0.739
6.203
15.760
13.651
0.073
0.101
10.621
0.211
3.813
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Table 4-5. Range of Organic Pollutant Influent Concentrations (mg/l) (continued)
Pollutant
HexanoicAcid
Isophorone
Methylene Chloride
m-Xylene
Naphthalene
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
n-Hexadecane
n-Octadecane
n-Tetradecane
n,n-Dimethylformamide
o+p-Xylene
o-Cresol
3entachlorophenol
3henol
Pyridine
p-Cresol
Tetrachloroethene
Tetrachloromethane
Toluene
Trans-1 ,2-dichloroethene
Trichloroethene
Trichlorofluoromethane
Tripropyleneglycol Methyl Ether
Vinyl Chloride
Metals
Min
0.414
2.144
0.050
0.018
0.045
0.142
0.088
0.062
0.086
0.040
0.032
0.144
0.011
0.061
0.011
0.080
0.015
Max
5.969
2.295
0.734
1.141
2.926
14.086
4.844
20.253
24.369
11.760
27.366
5.090
0.950
7.739
1.378
8.700
0.350
Oils
Min
0.807
0.179
0.117
0.266
0.133
0.901
0.312
0.246
0.795
0.369
0.769
0.063
1.695
0.137
0.477
30.587
Max
14.890
6.019
32.639
579.22
3.954
472.57
319.08
2.530
1,368.0
901.92
2,560.5
14.820
12.325
12.789
99.209
383.15
Organics
Min
1.111
0.060
33.113
0.056
0.112
0.023
0.013
0.180
0.657
0.553
0.132
0.220
2.235
1.391
0.148
1.171
1.194
0.024
0.290
Max
4.963
2.266
13.256
2.500
1.253
264.45
1.671
14.313
1.354
19.453
16.715
6.457
6.808
3.222
3,761.7
1.818
9.897
0.034
0.485
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4.5 WASTEWATER POLLUTANT DISCHARGES
\ '•
As previously discussed, most of the effluent monitoring data received from facilities
included non-CWT wastewater, such as other industrial waste streams and stormwater.
Due to the lack of effluent data for CWT wastewater, the EPA had to develop various
methods to estimate the current wastewater pollutant discharge. This section describes
the various methodologies used to estimate current performance.
4.5.1 Metals Subcategory Current Performance
As illustrated in Figure 4-1, most of the data supplied by Metals Subcategory
facilities represented data that included non-CWT wastewater in the form of
noncontaminated stormwater and other industrial stormwater added prior to discharge.
Therefore, the amount of a pollutant in the final effluent would be equal to the amount of
the pollutant in CWT process and the corresponding amount in the non-CWT process as
demonstrated in Equation 4.1.
CWT
Opera
Non-CWT
ation Operation
—
CWT
NON-CWT
TOTAL
Figure 4-3 Example of Non-CWT Wastewater Addition
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z * FTOTAL-x * FCWT+y * FNON _CWT
(4-1)
where:
z = Concentration of Pollutant in Final Effluent (mg/l),
FTOTAL = Total flow at Final Effluent (liters),
x = Concentration of Pollutant in CWT Process Effluent (mg/l),
FCWT ~ Total flow at CWT Process Effluent (liters),
y = Concentration of Pollutant in Final Effluent (mg/l), and
FNON-CWT = Total flow at Non-CWT Effluent (liters),
The EPA assimilated a database of the available monitoring data for facility effluent
discharges. For each facility, the EPA estimated the portion of non-CWT wastewater in
the facility discharge and calculated the Centralized Waste Treatment effluent
concentration by applying the following formulas (Eqns. 4-2 and 4-3) depending on the
source of the non-CWT wastewater. For facilities where the source of non-CWT
wastewater was stormwater, the following equation was used:
z*F
TOTAL
CWT
(4-1)
4-14
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For facilities in which the source of non-CWT wastewater was other industrial wastewater,
the following equation was used:
z*F
x=-
TOTAL
CWT
+.5*F
(4-1)
NON-CWT
In Equation 4-1, the value of variable y is dependent on the source of the non-CWT
wastewater. If the non-CWT wastewater was non-contaminated stormwater, the
noncontaminated stormwater was assumed to be significantly lower in concentration in
comparison to the process wastewater, and thus, y was set equal to 0. If the non-CWT
wastewater was other industrial wastewater, the other industrial wastewater was assumed
to be half as concentrated as CWT wastewater, and thus, the variable y was set equal to
.5*x. EPA concluded this value was a reasonable assumption. A comparison of
Centralized Waste Treatment raw wastewater with other promulgated industrial effluent
guidelines showed that Centralized Waste Treatment Industry raw wastewater was
significantly more concentrated that other industrial wastewater, in some instances 10
times more concentrated.
When possible, a facility's current performance was based upon information for
which data were reported. From the information submitted, average discharge
concentrations were calculated for each pollutant. Average discharge concentrations were
only calculated if more than two data points were available. For facilities that did not
submit analytical data, the average discharge concentration for the subcategory was used.
The estimated current performance for facilities in the Metals Subcategory is
presented in Table 4-6.
4-15
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Table 4-6. Metals Subcategory Current Performance
Pollutant
Current Discharge Concentration (mg/l)
Classicals
BOO;
Total Cyanide
Oil & Grease
TSS
1,904.58
77.84
270.42
1,371.02
Metals
Aluminum
Antimony
Arsenic
Barium
Boron
Cadmium
Chromium - Hexavalent
Chromium - Total
Cobalt
Copper
Iron
Lead
Manganese
Mercury
Molybdenum
Nickel
Selenium
Silver
Thallium
Tin
Titanium
Vanadium
Zinc
1.38
2.34
0.81
3.67
40.59
0.32
1.83
2.30
0.38
1.35
12.53
0.40
1.80
0.03
12.63
1.91
0.15
0.42
0.26
24.74
1.08
9.71
2.55
4-16
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Table 4-6. Metals Subcategory Current Performance (continued)
Pollutant
Current Discharge Concentration (mg/I)
Organics
1 , 1 , 1-Trichloroethane
1,1-Dichloroethane
1 , 1 -Dichloroethene
1 ,4-Dioxane
2-Butanone
2-Methylnaphthalene
2-Propanone
4-Chloro-3-methylphenoI
4-Methyl-2-pentanone
Acetophenone
Benzole acid
Benzyl alcohol
Biphenyl
Bis(2-ethylhexyl)phthalate
Carbon disulfide
Diphenyl ether
Ethyl benzene
Hexanoic acid
Methylene chloride
Naphthalene
n,n-DimethyIformamide
o+p-Xylene
Phenol
Styrene
Tetrachloroethene
Toluene
0.08
0.01
0.07
1.49
0.59
0.13
5.53
0.13
0.36
0.07
1.95
0.17
0.07
0.04
0.04
0.11
0.02
0.36
0.03
0.18
0.12
0.04
0.64
0.47
0.03
0.20
4-17
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4.5.2 Oils Subcategory Current Performance
The types of oils that are accepted for treatment can be characterized as stable or
unstable oil-water emulsion. Stable oil-water emulsions are difficult to separate because
the emulsions were created to make a specific product, such as lubricants and coolants.
Chemical emulsion-breaking is necessary to separate the mixture. Unstable oil-water
emulsions are more easy to separate than stable emulsions. Gravitational settling is
usually sufficient to separate the oil. and water phases. The wastewater generated from
chemical emulsion-breaking and settling requires treatment prior to discharge. From the
information gathered at facilities, the effluent from chemical-emulsion breaking was
characterized to be similar to the unstable oil-water emulsions prior to settling.
Most facilities in the Oils Subcategory have operations that are also categorized in
other Centralized Waste Treatment Industry subcategories. In most cases, waste receipts
were treated in a Chemical Emulsion-Breaking unit, and then commingled with the other
Subcategory wastewater. In reviewing data collected after emulsion-breaking and at the
point of mixing the waste streams, most pollutants of concern for the Oils Subcategory
were found at non-detect levels at the point of mixing. Therefore, it was apparent that the
pollutants of concern were being diluted prior to treatment.
The EPA estimated the current performance of most Oils Subcategory facilities to
be equivalent to the chemical emulsion breaking effluent. Credit was riot given for oily
wastewater commingled with other wastewater because dilution was normally the form of
treatment. A summary of the estimated current performance for the Oils Subcategory is
presented in Table 4-7.
4-18
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Table 4-7. Oils Subcategory Current Performance
Pollutant
Current Discharge
Concentration (mg/l)
Classical
BOD5
Oil and Grease
TSS
7,164.49
29,396.88
7,209.98
Metals
Aluminum
Antimony
Arsenic
Barium
Boron
Cadmium
Chromium
Cobalt
Copper
Iron
Lead
Manganese
Molybdenum
Nickel
Silver
Tin
Titanium
Zinc
48.93
1.34
0.22
2.53
239.36
0.24
2.20
0.72
15.79
232.26
8.15
7.39
3.05
26.44
1.08
2.10
0.38
42.00
Organics
1,1,1 -Trichloroethane
2-Butanone
2-Propanone
3.64
20.10
221.07
4-19
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Table 4-7. Oils Subcategory Current Performance (continued)
Pollutant
Current Discharge
Concentration (mg/l)
Organics (continued)
4-Chloro-3-Methylphenol
Benzene
Benzoic acid
Ethyl benzene
Hexanoic acid
Methylene chloride
m-Xylene
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
n-Hexadecane
n-Octadecane
n-Tetradecane
o+p-Xylene
Phenol
Tetrachloroethene
Toluene
Tripropyleneglycol Methyl Ether
22.31
8.25
16.81
6.61
5.38
1.47
11.37
91.78
3.03
70.39
42.69
3.08
153.22
95.36
282.72
5.19
4.59
2.16
33.95
86.47
4-20
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4.5.3 Organics Subcategory Current Performance
The problems in estimating current performance for the Organics Subcategory are
similar to that of the Metals Subcategory. Most Organics Subcategory facilities have other
industrial operations. The percentage of CWT wastewater in the overall facility flow was
minimal as was the amount of monitoring data submitted in the questionnaire. Therefore,
the EPA estimated performance based upon the treatment technologies in place.
Four different classifications were used to determine the current performance of
facilities in the Organics Subcategory. The first classification was used for facilities with
no treatment in place to reduce the pollutants in the organic waste stream. The average
raw waste concentration of pollutants was used for facilities in this classification. The
second classification was used for facilities which only had multi-media or sand filtration
as the on-site treatment technology for the organic waste stream. For these facilities, a
20 percent removal of TSS and metal compounds and no removal of other classical and
organic pollutants was assumed to occur from the raw waste concentration levels. The
third classification was used for facilities with multi-media or sand filtration units followed
by carbon adsorption. Removal of 20 percent for classical pollutants, 10 percent for metal
compounds, and 50 percent for organic pollutants from the raw wastewater were
estimated. The percent removals used were based on estimates of the treatment unit
effectiveness. The current performance for the remaining facilities was based on analytical
data collected for biological systems with and without multi-media or sand filtration units.
A summary of the current performance for the Organics Subcategory is presented
in Table 4-8.
4-21
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Table 4-8. Organics Subcategory Current Performance
Pollutant
Current Discharge Concentration
(mg/l)
Classicais
BOD,;
Total Cyanide
Oil & Grease
TSS
2,288.61
1.76
9.63
224.69
Metals
Aluminum
Antimony
Arsenic
Barium
Boron
Chromium
Cobalt
Copper
Iodine
Iron
Lead
Lithium
Manganese
Mercury
Molybdenum
Nickel
Phosphorus
Silicon
Strontium
Sulfur
Tin
2.04
0.22
0.10
1.94
4.89
0.11
0.27
0.32
7.60
3.50
0.09
14.91
0.38
0.02
0.52
3.37
3.14
2.28
4.67
841.15
0.97
4-22
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Table 4-8. Organics Subcategory Current Performance (continued)
Pollutant
Current Discharge Concentration
(mall)
Metals (continued)
Titanium
Zinc
0.21
0.25
Organics
1,1,1 ,2-Tetrachloroethane
1,1,1 -Trichloroethane
1 ,1 ,2-Trichloroethane
1,1-Dichloroethane
1,1-Dichloroethene
1 ,2,3-Trichloropropane
1 ,2-Dibromoethane
1 ,2-Dichlorobenzene
1 ,2-Dichloroethane
2,3,4,6-TetrachlorophenoI .
2,3-Dichloroaniline
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
2,4-Dimethyl phenol
2-Butanone
2-Chlorophenol
2-Hexanone
2-Picoline
2-Propanone
4-Methyl-2-pentanone
Acetophenone
Benzene
Benzoic acid
0.16
0.18
0.30
0.16
0.15
0.15
0.20
0.06
0.25
3.52
0.10
0.39
0.72
0.04,
3.05
0.06
1.19
0.20
164.89
0.79
0.04
0.20
0.36
4-23
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Table 4-8. Organics Subcategory Current Performance (continued)
Pollutant
Current Discharge Concentration
(mg/I)
Organics (continued)
Bromodichloromethane
Carbon disulfide
Chlorobenzene
Chloroform
Diethyl ether
Ethyl benzene
Hexanoic acid
Isophorone
Methylene chloride
m-Xylene
Naphthalene
n.n-Dimethylformamide
o&p-Xylene
o-Cresol
Pentachlorophenol
Phenol
Pyridine
p-Cresol
Tetrachloroethene
Tetrachloromethane
Toluene
trans-1 ,2-DichIoroethene
Trichloroethene
Trichlorofluoromethane
Vinyl Chloride
0.15
0.22
0.15
0.64
0.76
0.17
0.19
0.05
42.07
0.17
0.04
0.77
0.16
0.17
1.79
0.36
0.18
0.10
0.61
0.18
15.75
0.25
0.92
0.16
0.19
4-24
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SECTIONS
POLLUTANTS AND POLLUTANT PARAMETERS
SELECTED FOR REGULATION
As previously discussed, EPA evaluated all available data characterizing
wastewater for this industry in order to determine the pollutants of concern for the
Centralized Waste Treatment Industry. This section discusses the pollutants and pollutant
parameters detected in the Centralized Waste Treatment Industry.
5.1 POLLUTANT PARAMETERS
Pollutant parameters, which include conventional pollutants, such as TSS and Oil
and Grease, and non-conventional pollutant parameters, such as chemical oxygen
demand (COD) arid total organic carbon (TOC), are general indicators of water quality
rather than markers of specific compounds. Because most of the industry are indirect
dischargers, they are not subject to limitations for conventional pollutants normally
included in direct discharge permits but not in indirect discharge permits.
The pollutant parameters proposed for regulating are a function of the subcategory.
In the Metals Subcategory, the most important pollutant parameter is total suspended
solids because of the correlation to treatment unit effectiveness. In general, TSS is an
important parameter for all subcategories because of its correlation to the type of waste
accepted for treatment, and will be covered for all subcategories. Oil and Grease is
proposed for regulation for the Metals Subcategory because of its ability to interfere with
the performance of metals treatment systems. Oil and Grease is an extremely important
measure for estimating treatment unit performance for the Oils Subcategory. The most
important parameter for the Organics Subcategory is BOD5 because it measures
biodegradability of organic compounds.
5-1
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5.2 PRIORITY AND NON-CONVENTIONAL POLLUTANTS
In the beginning of the industry study, more than 480 priority and non-conventional
pollutants, listed in Appendix B, were analyzed. These pollutants are a combination of all
pollutants for which the EPA has approved analytical methods, including RCRA and TSCA
compounds. After the initial two sampling episode, Dioxins/Furans and
Pesticides/Herbicides were no longer analyzed because they were not detected in the
waste streams at treatable concentrations. CWT facilities that are RCRA permitted
operations are prohibited from receiving either dioxins/furans or pesticides/herbicides
because the RCRA required treatment for these compounds is incineration.
The priority and non-conventional pollutants to be regulated were determined by
a series of data reviews. Analytical data from raw wastewater samples collected during
the EPA Sampling Program were reviewed to determine the number of times a pollutant
was detected at treatable levels. In most cases, treatable levels were set at 10 times the
minimum level. This would ensure that pollutants detected only at trace amounts would
not be regulated. Regulation would not be required because most pollutants found at trace
amounts will be indirectly controlled through regulation of other pollutants by the proposed
regulations.
The initial pollutants of concern for each subcategory were derived from the
pollutants which were detected at a treatable level a minimum of three times in the
subcategory raw waste stream. A minimum number of times (3) for detection was
established such that a pollutant infrequently detected would not be regulated for the
entire subcategory. The final list of pollutants to be regulated was later refined depending
on the quantity of pollutant detected and the ability of a pollutant to be controlled
depending upon the regulation of other pollutants.
After evaluating all of these factors, the Agency selected for regulation 63
pollutants. The final list of pollutants to be regulated for each subcategory is presented
in Table 5-1.
5-2
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Table 5-1
Pollutants Selected for Regulation
Metals Subcategory
Oils Subcategory
Organics Subcategory
Aluminum
Antimony
Arsenic
Barium
Cadmium
Chromium
Cobalt
Copper
Hexavalent Chromium
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Silver
Tin
Titanium
Total Cyanide
Zinc
1,1,1-Trichloroethane
2-Propanone
4-chloro-3-methyl phenol
Aluminum
Barium
Benzene
Butanone
Cadmium
Chromium
Copper
Ethyl Benzene
Iron
Lead
Manganese
Methylene Chloride
m-Xylene
Nickel
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
n-Hexadecane
n-Octadecane
n-Tetradecane
o&p-Xylene
Tetrachloroethene
Tin
Toluene
Tripropyleneglycol
Zinc
1,1,1,2-Tetrachloroethane
1,1,1 -Trichloroethane
1,1,2-Trichloroethene
1,1-Dichloroethane
1,2,3-Trichloropropane
1,2-Dibromoethane
1,2-Dichloroethane
2,3-Dichloroaniline
2-Propanone
4-Methyl-2-Pentanone
Acetophenone
Aluminum
Antimony
Barium
Benzene
Benzoic Acid
Butanone
Carbon Disulfide
Chloroform
Diethyl Ether
Hexanoic Acid
Lead
Methylene Chloride
Molybdenum
m-Xylene
o-Cresol
p-Cresol
Phenol
Pyridine,
Tetrachloroethene
Tetrachloromethane
Toluene
trans-1,2-DichIoroethene
Trichloroethene
Vinyl Chloride
Zinc
EPA is not selecting pollutants for regulation for various reasons. The initial
determination of pollutants to be included in the regulation was the number of times the
pollutant was detected in raw wastewater samples. After these pollutants were removed,
5-3
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pollutants used as treatment chemicals were also removed from all data. Calcium,
Sodium, Potassium, and Phosphorus were the pollutants found in treatment chemicals
removed from the regulated list for all subcategories. These pollutants are added to the
process and are not toxic to water. Pollutants were also removed from the list to be
regulated if the pollutant was only detected at one facility, and therefore, not present
throughout the industry. The only pollutants excluded from regulation due to the
presence at an isolated facility were Gallium and Strontium from the Organics
Subcategory.
Additional pollutants were removed from the regulated list if the average influent
concentration detected was below a treatable level. For most pollutants, the
concentration level for was set at 100 ug/l or 10 times the analytical minimum level. For
Mercury, the concentration was less than 5ug/l due to the toxicity of Mercury in water.
These pollutants are presented in Table 5-2.
Table 5-2
Pollutants Excluded from Regulation Due to the Concentration Detected
Metals Subcategory
Beryllium
Yttrium
Endosulfan Sulfate
Oils Subcategory
Antimony
Arsenic
Beryllium
Mercury
Selenium
Yttrium
Organics Subcategory
Arsenic
Cadmium
Mercury
Titanium
Yttrium
1,1-Dichloroethane
1,2-Dimethyl phenol
2-Chl9ropheriol
2-Hexanone
2-Picoline
Benzyl Alcohol
Bromodichloromethane
Chlorobenzene
Ethyl Benzene
Isophorone
Naphthalene
n,n-Dimethylformamide
o&p-Xylene
Trichlorofluoromethane
Endosulfan Sulfate
5-4
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Pollutants were also excluded from regulation when they were not detected or
analyzed at the facilities used for the proposed technology option. Some pollutants were
excluded from analysis to reduce the costs of sampling episodes. The pollutants
excluded from analysis were found at concentrations similar to the treatability levels
discussed previously and are not toxic at these concentrations. These pollutants are
listed in Table 5-3.
Table 5-3
Pollutants Excluded from Regulation Due to Lack of Detection or Analysis at
the Technology Option Facility
Metals Subcategory
Oils Subcategory
Organics Subcategory
Cerium
Gallium
Indium
Iodine
Iridium
Lithium
Lutetium
Neodymium
Niobium
Osmium
Praseodymium
Rhenium
Selenium
Silicon
Strontium
Sulfur
Tantalum
Tellurium
Thallium
Thorium
Tungsten
Uranium
Ytterbium
Zirconium
All organic pollutants
None
None
5-5
-------
Additional pollutants were excluded from regulation because the technology option
proposed was not effective in treating the pollutant (i.e., pollutant concentrations increase
across the treatment system). These pollutants are listed in Table 5-4.
Table 5-4
Pollutants Excluded from Regulation Due to ineffective Treatment
Metals Subcategory
Oils Subcategory
Organics Subcategory
None
Benzoic Acid
Hexanoic Acid
Phenol
2,3,4,6-
Tetrachlorophenol
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
Boron
Iodine
Lithium
Magnesium
Manganese
Nickel
Pentachlorophenol
Tin
5.3 SELECTION OF POLLUTANTS TO BE REGULATED FOR PSES AND PSNS
Indirect dischargers in the CWT Industry send their wastewater streams to a
POTW for further treatment, unlike direct dischargers, whose wastewater will receive no
further treatment once it leaves their facility. Therefore, the levels of pollutants allowable
in the wastewater of an indirect discharger are dependent upon 1) whether a given
pollutant "passes through" the POTWs treatment system or 2) whether additional
treatment provided by the POTW will result in removal of the pollutant to a level
equivalent to that obtained through treatment by a direct discharger.
5-6
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5.3.1 Pass-Through Analysis Approach
To establish PSES, EPA must first determine which of the CWT pollutants of
concern (identified earlier in this section) pass through, interfere with, or are incompatible
with the operation of POTWs (including interferences with sludge practices). EPA
determines pollutant pass-through by comparing the percentage removed by POTWs with
the percentage removed by direct dischargers using BPT/BAT technology. A pollutant
"passes through" POTWs when the average percentage removed by well-operated
POTWs nationwide (those meeting secondary treatment requirements) is less than the
percentage removed by CWT direct dischargers complying with BPT/BAT limitations for
a given pollutant. EPA has assumed, for the purposes of this analysis and based upon
the data it received, that the untreated wastewater at indirect discharge facilities is not
significantly different than that from direct discharge facilities.
This approach to the definition of pass-through satisfies two competing objectives
set by Congress: (1) that standards for indirect dischargers be equivalent to standards
for direct dischargers and (2) that the treatment capability and performance of the POTW
be recognized and taken into account in regulating the discharge of pollutants from
indirect dischargers. Rather than compare the mass or concentration of pollutants
discharged by the POTW with the mass or concentration of pollutants discharged by a
BAT facility, EPA compares the percentage of the pollutants removed by the facility with
the POTW removal. EPA takes this approach because a comparison of mass or
concentration of pollutants in a POTW effluent with pollutants in a BAT facility's effluent
would not take into account the mass of pollutants discharged to the POTW from non-
industrial sources nor the dilution of the pollutants in the POTW effluent to lower
concentrations from the addition of large amounts of non-industrial wastewater.
5-7
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5.3.2 50 POTW Study Data Base
For previous effluent guidelines efforts, a study of 50 well-operated POTWs was
used to establish POTW removals for comparison with facility removals for the pass-
through analysis. The earlier work done with this data base included an in-depth
comparison of data editing scenarios. The main concern with using the data is the
possibility that low calculated POTW removals might simply reflect low influent
concentrations, and would not be true measures of treatment effectiveness. The editing
rules used in this guideline were devised to minimize this possibility.
First, a POTW/pollutant combination must have at least three influent values to be
kept in the analysis. Then, because the data base includes influent levels that are close
to the pollutants' analytical nominal detection limits (NOMDLs), the POTW data were
edited to eliminate average POTW/pollutant influent levels less than 10 times the
NOMDLs and the corresponding effluent data, except in the cases where the average
influent concentration did not exceed 10 times the NOMDL. In these cases, the data were
edited to eliminate average POTW/pollutant influent values less than 20 ^gl\ and the
corresponding effluent data. With regard to industry data, EPA considers influent levels
in excess of 10 times the pollutant's NOMDL at a facility to be appropriate for use in
setting effluent limitations. Secondly, EPA has historically found that pollutants with low
influent concentrations (less than 20 //g/l) have shown corresponding effluent
concentrations that were consistently below the NOMDL and could not be quantified.
The remaining averaged POTW/pollutant influent values and the corresponding
averaged effluent values were used to calculate the average removal for each
POTW/pollutant. The median percent removal achieved for each pollutant was
determined from these averaged POTW/pollutant values.
5-8
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5.3.3 RREL Treatability Data Base
Due to the large number of pollutants considered for this industry, additional data
from the EPA Risk Reduction Engineering Laboratory (RREL) Treatability Database were
used to supplement the 50 POTW Study data. Due to the organization of this data base,
the editing rules used for the POTW data base were modified appropriately.
For each of the pollutants, data from the liquid waste portion of the RREL
Treatability Database were obtained. These files were edited so that only treatment
technology data for activated sludge, aerobic lagoons, and activated sludge with filtration
remained. These technologies are representative of typical POTW secondary treatment
operations. The files were further edited to include only information pertaining to
domestic or industrial wastewater, unless only other types of wastewater data were
available. Only full-scale or pilot-scale data were used; bench-scale data were edited
out. Only data from a paper in a peer-reviewed journal or government report or data base
were retained; all lesser-quality references were deleted. Additionally, the retained
references were reviewed and non-applicable study data were accordingly eliminated.
Because the data base is organized into groupings of influent values, the influent editing
rules used for the 50 POTW Study data base could not be applied here.
From the remaining pollutant removal data, the average percent removal for each
pollutant was calculated.
5.3.4 Final POTW Data Editing
For each pollutant, the edited percent removals from the 50 POTW Study and
RREL Treatability Data Base were compared. The final percent removal for each
pollutant was chosen based on a data hierarchy, which was related to the quality of the
data source. This hierarchy was:
5-9
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1. 50 POTW Study data (10 times NOMDL edit);
2. 50 POTW Study data (20 //g/l edit);
3. RREL Treatability data (domestic wastewater only edit, if three or more data
points);
4. RREL Treatability data (domestic and industrial wastewater edit); then
5. Generic pollutant group removal data (see discussion below).
After the editing of the 50 POTW and RREL Treatability data was finished, there
were some CWT pollutants for which no data were available. To determine average
removals for these pollutants, all of the CWT pollutants were assigned to a generic group
by chemical structure. These groups were:
A. Inorganic Elements;
B. Halogenated Hydrocarbons;
C. Hydrocarbons;
D. Aromatic Hydrocarbons;
E. Halogenated Aromatics;
F. Organic Acids;
G. Aromatic Alcohols;
H. Phenolics;
I. Halogenated Phenolics;
J. Pesticides;
K. Heterocyclics;
L. Ketones;
M. Aromatic Ketones;
N. Cyclic Ketones;
O. Polyaromatic Hydrocarbons;
P. Phthalates;
Q. Ethers; and
R. Amides.
All of the available removals for the pollutants within a given group were averaged;
this average removal was then assigned to any pollutant within that group that did not
previously have a removal value. After the final selection of CWT pollutants to be
regulated, the only generic removals that were applicable were for Groups C
5-10
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(Hydrocarbons) and Q (Ethers); these group removals are presented in Tables 5-5 and
5-6, respectively. The final POTW removals for the CWT pollutants, determined via the
data use hierarchy, are presented in Table 5-7.
Table 5-5. Generic Removals for Group C: Hydrocarbons
Pollutant Parameter
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
n-Hexadecane
n-Octadecane
n-Tetradecane
Average Group Removal
Removal (%)
9.00
88.00
95.05
92.40
_
-
«.
_
71.11
Source of Data
RREL - All Wastewater Edit
RREL - AH Wastewater Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
_
-
.
-
-
Table 5-6. Generic Removals for Group Q: Ethers
Pollutant Parameter
Diethyl Ether
Diphenyl Ether
Tripropyleneglycol Methyl Ether
Average Group Removal
Removal (%)
7.00
86.53
_
46.77
Source of Data
RREL - All Wastewater Edit
RREL - All Wastewater Edit
_
'
5-11
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Table 5-7. Final POTW Removals for CWT Pollutants
Pollutant Parameter
1 .1 ,1 ,2-Tetrachloroethane
1 ,1 ,1-Trichloroethane
1 ,1 ,2-Triehloroethane
1,1-Dichloroethene
1 ,2,3-TrichIoropropane
1 ,2-Dibromoethane
1 ,2-Dichloroethane
2,3-Dichloroaniline
2-Propanone
4-Chloro-3-methylphenol
4-MethyI-2-pentanone
Acetophenone
Aluminum
Antimony
Arsenic
Barium
Benzene
Benzole Acid
Butanone
Cadmium
Carbon Disulfide
Chloroform
Chromium
Cobalt
Copper
Diethyl Ether
Ethyl Benzene
Hexavalent Chromium
Hexanoic Acid
Iron
Lead
Maqnesium
Removal (%)
23.00
90.45
55.98
75.34
5.00
17.00
89.03
41.00
83.75
63.00
87.87
95.34
16.81
71.13
90.89
90.20
94.76
80.50
91.83
90.05
84.00
73.44
91.25
4.81
84.11
7.00
93.79
5.68
84.00
83.00
91.83
31.83
Source of Data
RREL - All Wastewater Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW ->20,wg/l Edit
50 POTW ->20M9/I Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
50 POTW - 1 0 x NOMDL Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
50 POTW - 1 0 x NOMDL Edit
RREL - All Wastewater Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
RREL - All Wastewater Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
RREL - All Wastewater Edit
RREL - Domestic Wastewater Edit
50 POTW - 1 0 x NOMDL Edit
RREL - All Wastewater Edit
5-12
-------
Table 5-7. Final POTW Removals for CWT Pollutants (continued)
Pollutant Parameter
Manganese
Mercury
Methyle'ne Chloride
Molybdenum
m-Xylene
Nickel
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
n-Hexadecane
n-Octadecane
n-Tetradecane
o&p-Xylene
o-Cresol
Phenol
Pyridine
p-Cresol
Silver
Tetrachloroethene
Tetrachloromethane
Tin
Titanium
Toluene
Total Cyanide
trans-1 ,2-Dichloroethene
Trichloroethene
Tripropyleneglycol Methyl Ether
Vinyl Chloride
Zinc
Removal (%)
40.60
90.16
54.28
52.17
65.40
51.44
9.00
88.00
95.05
92.40
71.11
71.11
71.11
71.11
95.07
52.50
95.25
95.40
71.67
92.42
84.61
87.94
65.20
68.77
96.18
70.44
70.88
86.85
46.77
93.49
77.97
Source of Data
RREL - All Wastewater Edit
50 POTW - 10 x NOMDL Edit
50 POTW - 10 x NOMDL Edit
RREL - Domestic Wastewater Edit
RREL - All Wastewater Edit
50 POTW - 1 0 x NOMDL Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
Generic removal-Group C
Generic removal-Group C
Generic removal-Group C
Generic removal-Group C
RREL - Domestic Wastewater Edit
RREL - All Wastewater Edit
50 POTW - 1 0 x NOMDL Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
RREL - All Wastewater Edit
RREL - All Wastewater Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
50 POTW - >20 ua/\ Edit
50 POTW - 1 0 x NOMDL Edit
Generic removal-Group Q
50 POTW - 1 0 x NOMDL Edit
50 POTW - 1 0 x NOMDL Edit
5-13
-------
5.3.5 Final Pass-Through Analysis Results
For each CWT option/pollutant, the daily removals were calculated using the
BPT/BAT data. Then, the average overall BPT/BAT removal was calculated for each
pollutant from the daily removals. The averaging of daily removals is appropriate for this
industry as the BPT/BAT treatment technologies typically have retention times of less
than one day. For the final pass-through analysis, the final POTW removal determined
for each CWT pollutant was compared to the percent removal achieved for that pollutant
using the BPT/BAT option treatment technologies.
Those pollutants that were deemed to not pass though were then subjected to a
volatile override test. A volatile override was applied where the overall percent removal
estimated at a POTW included in substantial part the emission of the pollutant to the air
rather than actual treatment. Therefore, even though the POTW removal data indicated
that a volatile pollutant would not pass through, the volatile override warranted
establishment of PSES for that pollutant.
The Henry's Law Constant for a pollutant gives a qualitative indication of its
volatility. For pollutants with values less than 10"7 atm-m?mole, the chemical is less
volatile than water; for pollutants around 10'3, volatilization from water will be rapid. The
cut-off used for the volatile override was a Henry's Law Constant of 2.4 x 10'5 atm-
nrrVmole, or 1CT3 mg/m3/mg/m3. EPA considers this cut-off to be a conservative edit for
pollutants of medium to high volatility.
For the CWT pass-through analysis, 12 organic pollutants were found to not pass
through after the preliminary analysis, and were therefore reviewed for volatility. The
Henry's Law Constants for these pollutants are presented in Table 5-8. Of these 12
pollutants, eight were affected by the volatile override; therefore, these pollutants are
now considered to pass through POTWs.
5-14
-------
Table 5-8. Volatile Override Analysis for CWT Pollutants
Pollutant Parameter
1 , 1 , 1-Trichloroethane
2-Butanone
2-Propanone
Benzene
Carbon Disulfide
Methylene Chloride
o&p-Xylene
Phenol
Pyridine
Toluene
Tripropyleneglycol Methyl Ether
Vinyl Chloride
Henry's Law Constant
(atm-m3/mole)
4.8 *10'3
2.7 *10'5
2.1 * ID'5
5.6 *10'3
1.2 *10'2
3.2 *10'3
7.0 *10'3
1.3*10*
2.1 * 10-6
5.9 * 10'3
No data available
2.8 *10'2
Volatile Override
Yes
Yes
No
Yes
Yes
Yes
Yes
No
No
Yes
No
Yes
Of the 87 pollutants regulated under BAT, 78 were found to pass through for
Regulatory Option 1 (the combination of Metals Option 3, Oils Option 2, and Organics
Option 1), and 81 were found to pass through under Regulatory Option 2 (the combination
of Metals Option 3, Oils Option 3, and Organics Option 1), and are proposed for PSES.
The final pass-through analysis results for the CWT Metals, Oils, and Organics
Subcategory Options are presented in Tables 5-9, 5-10, and 5-11, respectively.
5-15
-------
Table 5-9. Final Pass-Through Results for Metals Subcategory Option 3
Pollutant Parameter
Aluminum
Antimony
Arsenic
Barium
Cadmium
Chromium
Cobalt
Copper
Hexavalent
Chromium
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Silver
Tin
Titanium
Total Cyanide
Zinc
Option 3
Removal
(%)
99.99
99.76
99.88
85.58
99.93
99.99
99.20
100.00
98.55
99.96
99.97
99.81
99.97
99.81
99.67
99.55
99.90
99.98
95
99.99
POTW
Removal
(%)
16.81
71.13
90.89
90.20
90.05
91.25
4.81
84.11
5.68
83.00
91.83
31.83
40.60
90.16
51.44
92.42
65.20
68.77
70.44
77.97
Prelim.
Pass-
Through
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Volatile
Override
_
_
_
NA
_
_
_
_
-
_
_
_
_
_
_
..
_
_
-
Final
Pass-
Through
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
5-16
-------
Table 5-10. Final Pass-Through Results for Oils Subcategory Options 2 and 3
Pollutant Parameter
1 ,1 ,1-Trichioroethane
2-Propanone
4-Chloro-3-methylphenol
Aluminum
Barium
Benzene
Butanone
Cadmium
Chromium
Copper
Ethyl Benzene
Iron
Lead
Manganese
Methylene Chloride
m-Xy!ene
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
n-Hexadecane
n-Octadecane
n-Tetradecane
Nickel
o&p-Xylene
Tetrachloroethene
Tin
Toluene
Tripropyleneglycol Methyl
Ether
Zinc
Option
Removal (%)
2
80.21
96.38
80.60
97.48
99.37
64.53
96.37
97.46
84.67
99.66
94.20
93.24
92.57
80.60
51.74
95.08
99.90
97.77
99.85
99.69
97.81
99.76
99.13
99.37
24.40
94.03
91.29
82.87
83.23
27.12
68.82
3
97.71
95.97
98.40
99.80
99.96
93.89
95.63
99.20
99.77
99.96
99.63
99.92
99.72
99.66
81.30
99.80
99.96
99.02
99.94
99.86
99.04
99.89
99.62
99.72
98.37
99.73
99.13
94.35
98.53
82.46
98.51
POTW
Removal
(%)
90.45
83.75
63.00
16.81
90.20
94.76
91.83
90.05
91.25
84.11
93.79
83.00
91.83
40.60
54.28
65.40
9.00
88.00
95.05
92.40
71.11
71.11
71.11
71.11
51.44
95.07
84.61
65.20
96.18
46.77
77.97
Prelim
Pass-
Throuqh
2
No
Yes
Yes
Yes
Yes
No
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
No
No
No
3
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Volatile
Override
Yes
-
--
-
-
Yes
-
-
NA
-
-
-
-
-
Yes
-
-
-
-
-
-
-
-
-
NA
Yes
'
-
Yes
NV
NA
Final
Pass-
Through
2
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
No
No
3
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
5-17
-------
Table 5-11. Final Pass-Through Results for Organics Subcategory Option 1
Pollutant Parameter
1 ,1 ,1 ,2-TetrachIoroethane
1 ,1 ,1-TrichIoroethane
1 ,1 ,2-Triehloroethane
1 ,1-DichIoroethene
1 ,2,3-TrichIoropropane
1,2-Dibromoethane
1 ,2-Dichloroethane
2,3-Dichloroaniline
2-Propanone
4-MethyI-2-pentanone
Acetophenone
Aluminum
Antimony
Barium
Benzene
Benzoic Acid
Butanone
Carbon Disulfide
Chloroform
Diethyl Ether
Hexanoic Acid
Lead
Methylene Chloride
Molybdenum
m-Xylene
o-Cresol
Phenol
Pyridine
p-Cresol
Tetrachloroethene
Tetrachloromethane
Toluene
trans-1 ,2-Dichloroethene
Trichloroethene
Vinyl Chloride
Zinc
Option 1
Removal
(%)
98.86
91.78
93.71
89.70
95.82
99.74
99.17
67.33
79.44
96.00
97.38
83.57
72.13
94.29
91.40
96.88
69.80
68.01
96.22
69.83
90.43
66.49
97.29
75.38
91.09
99.84
90.34
60.17
92.32
93.60
99.80
98.18
95.82
92.28
92.19
73.75
POTW
Removal
(%)
23.00
90.45
55.98
75.34
5.00
17.00
89.03
41.00
83.75
87.87
95.34
16.81
71.13
90.20
94.76
80.50
91.83
84.00
73.44
7.00
84.00
91.83
54.28
52.17
65.40
52.50
95.25
95.40
71.67
84.61
87.94
96.18
70.88
86.85
93.49
77.97
Prelim Pass-
Through
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Volatile
Override
-
-
-
-
-
-
-
-
No
-
-
-
-
-
Yes
-
Yes
Yes
-
-
_
NA
-
-
-
-
No
No
-
-
-
_
-
-
Yes
NA
Final Pass-
Through
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
5-18
-------
5.4 REFERENCES
Howard, Philip H., Environmental Fate and Exposure for Organic Chemicals - Volume I -
Large Production and Priority Pollutants, Lewis Publishers, Inc., Chelsea Ml, 1989.
Stecher, Paul G., et al., Editor, The Merck Index - 8th Edition, Merck & Co., Inc., Rahway,
NJ, 1968.
U.S. EPA, Development Document for Effluent Limitations Guidelines and Standards for
the Organic Chemicals, Plastics and Synthetic Fibers Point Source Category - EPA 440/1-
87/009, Washington, DC, October 1987.
U.S. EPA, 50 POTW Study Data Base, 1978-80.
U.S. EPA, Methods for Chemical Analysis of Water and Wastewater, Cincinnati, OH,
1979.
U?S. EPA, Risk Reduction Engineering Laboratory (RREL) Treatability Data Base -
Version 5.0 (Draft), Cincinnati, OH, 1994.
Weast, Robert C., Editor, Handbook of Chemistry and Physics - 55th Edition, CRC Press,
Inc., Cleveland, OH, 1974.
5-19
-------
-------
SECTION 6
WASTEWATER TREATMENT TECHNOLOGIES
This section discusses the technologies available for the treatment of wastewater
generated by the CWT Industry. Many of these technologies are currently in operation
at CWT facilities; the others were chosen for inclusion in this discussion based on their
potential for application in treating the CWT pollutants of concern.
The processes presented here include both those that remove pollutant
contaminants in wastewater and those that destroy them. If a wastewater treatment
technology that removes, rather than destroys, a pollutant is selected, then a treatment
residual will be generated. In many instances, this residual is in the form of a sludge,
which is typically further treated on-site to prepare it for disposal. Subsection 6.4
discusses technologies which can be used to dewater sludges to concentrate them prior
to disposal. Other types of treatment residuals, such as spent activated carbon and filter
media, are generally sent off-site to a vendor facility for management.
6.1 PHYSICAL/CHEMICAL/THERMAL
TECHNOLOGIES
WASTEWATER TREATMENT
The wastewater treatment technologies presented in this subsection comprise the
majority of operations found at CWT facilities. These technologies are generally efficient
and cost-effective. Included among these technologies are processes, such as filtration,
which utilize physical interactions to achieve pollutant removal, and others, such as
chemical precipitation, which utilize a chemical reaction to change the form of a pollutant
so that it can be removed from the waste stream. Other technologies, such as the
thermal destruction of cyanide, use heat to destroy pollutants.
6-1
-------
6.1.1
Chemical Precipitation
6.1.1.1
Technology Description
Chemical precipitation is used for the removal of metal compounds from
wastewater. In the chemical precipitation process, soluble metallic ions and certain
anions are converted to insoluble forms, which precipitate from the solution. The
precipitated metals are subsequently removed from the wastewater stream by liquid
filtration or clarification. The performance of the process is affected by chemical
interactions, temperature, pH, solubility, and mixing effects.
Various chemicals can be used as precipitants; these include caustic (NaOH), lime
(Ca(OH)2), soda ash, sulfide, ferrous sulfate, and acid. Hydroxide precipitation is effective
in removing such metals as antimony, arsenic, chromium, copper, lead, mercury, nickel,
and zinc. Sulfide precipitation primarily removes mercury, lead, and silver.
Hydroxide precipitation using lime or caustic is the most commonly-used means
of chemical precipitation, and of these, lime is used more often than caustic. The chief
advantage of lime over caustic is its lower cost. However, lime is more difficult to handle
and feed, as it must be slaked, slurried, and mixed, and can plug the feed system lines.
Lime also produces a larger volume of sludge, and the sludge is generally not suitable
for reclamation due to its homogeneous nature. Also, dewatered metal sludge is typically
sold to smelters for reuse, and the calcium compounds in lime precipitation sludge
interfere with smelting. The metals from caustic precipitation sludge can often be
recovered. The reaction mechanism for precipitation of a divalent metal using lime is
shown below:
NT + Ca(OH)2 -> M(OH)2 + Ca++
And, the reaction mechanism for precipitation of a divalent metal using caustic is:
IVT + 2NaOH -» M(OH)2 + 2Na+
6-2
-------
In addition to the type of treatment chemical chosen, another important design
factor in the chemical precipitation operation is pH. Metal hydroxides are amphoteric,
meaning that they can react chemically as acids or bases. As such, their solubilities
increase toward both lower and higher pH levels. Therefore, there is an optimum pH for
precipitation for each metal, which corresponds to its point of minimum solubility. Another
key consideration in a chemical precipitation application is the detention time, which is
specific to the wastewater being treated and the desired effluent quality. It may take from
less than an hour to several days to achieve adequate precipitation of the dissolved metal
compounds.
Chemical precipitation is a two-step process. It is typically performed in batch
operations where the wastewater is first mixed with the treatment chemical in a tank. The
mixing is typically achieved by mechanical means such as mixers or recirculation
pumping. Then, the wastewater undergoes a separation/dewatering process such as
clarification or filtration, where the precipitated metals are removed from solution. In a
clarification system, a flocculant is sometimes added to aid in the settling process. The
resulting sludge from the clarifier or filter must be further treated, disposed, or recycled.
A typical chemical precipitation system is shown in Figure 6-1<
The batch operation aspect of chemical precipitation makes it an easily-adapted
process for the CWT Industry, where the waste receipts can be highly variable. A facility
can hold its wastes and segregate them by pollutant content for treatment. This type of
waste treatment management, called selective metals precipitation, can be implemented
in order to concentrate on one or two major pollutants of concern. This application of
chemical precipitation uses several tanks to allow the facility to segregate its wastes into
smaller batches, thereby avoiding interference with other incoming waste receipts and
increasing treatment efficiency. These specific operations would also produce specific
sludges containing only the target metals, making them suitable for reclamation.
6-3
-------
Treatment Chemical
i
Wastewater
Influent
I
Chemical Controller
CO
- Treated
Effluent
Chemical Precipitation Tank
Figure 6-1. Chemical Precipitation System Diagram
6-4
-------
6.1.1.2 Treatment Performance
The effluent quality achievable with chemical precipitation depends upon the metals
present in the wastewater and the process operating conditions. It is a demonstrated and
widely-used technology, often removing metal pollutants down to levels of 1 jig/l or less.
According to the WTI Questionnaire data base, there are 184 individual
applications of chemical precipitation in the CWT Industry. Often a single facility will use
several chemical precipitation applications, depending upon the type of waste being
treated. Four specialized applications of chemical precipitation were identified as BPT for
the Metals Subcategory of the CWT Industry; these are hydroxide chemical precipitation
and selective metals precipitation followed by secondary precipitation, then tertiary
precipitation.
During the CWT project, EPA conducted sampling at three facilities (CWT QIDs
059, 105, and 230) that use hydroxide chemical precipitation systems. At QID 059, the
chemical precipitation effluent was sent through a filter press. The effluents from the
chemical precipitation systems at QIDs 105 and 230 were treated in clarifiers. The
performance data obtained for these applications are presented in Tables 6-1, 6-2, and
6-3. As these data show, the systems at QIDs 059 and 105 achieved high metals
removals, in the 90 to 99.99 percent range. The data for QID 230 shows poorer
performance.
EPA also sampled one facility (CWT QID 130) that operates selective metals
precipitation processes (for both solid and liquid waste receipts), followed by secondary
and tertiary precipitation systems. The effluents from the selective metals precipitation
processes and the secondary precipitation system were filtered, and the effluent from the
tertiary precipitation system was clarified. The sampling data for these individual systems
are presented in Tables 6-4, 6-5, 6-6, and 6-7. The sampling data for the overall metals
treatment train at QID 130 (selective metals precipitation, secondary precipitation, and
tertiary precipitation) is presented in Table 6-8. As this table shows, the overall system
at QID 130 achieved removals of greater than 99 percent for each of the 10 metals
presented.
6-5
-------
Table 6-1. Chemical Precipitation System Performance Data for CWT QID 059
Parameter
Aluminum
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Silver
Zinc
Influent Avg (u.g/1)
620,080
244
228,772
286,191
6,702
33,596
1,458
972,600
1,845
90,040
Effluent Avg (|ig/l)
2,125
5 (ND)
384
60
50
72
86
90,834
91
2,257
Removal (%)
99.66
97.95
99.83
99.98
99.25
99.79
94.10
90.66
95.08
97.49
Table 6-2. Chemical Precipitation System Performance Data for CWT QID 105
Parameter
Aluminum
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Silver
Zinc
Influent Avg (jig/l)
400,030
48,065
3,652,458
454,740
84,462
26,175
106
631 ,996
2,488
473,078
Effluent Avg (|ig/l)
12,133
217
3,300
16,300
480 (ND)
53
0.2 (ND)
4,243
53
2,427
Removal (%)
96.97
99.55
99.91
96.42
99.43
99.80
99.81
99.33
97.89
99.49
ND = Not detected
6-6
-------
Table 6-3. Chemical Precipitation System Performance Data for CWT QID 230
Parameter
Aluminum
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Zinc
Influent Avg (|ig/l)
37,648
22
317
28,136
415
2,214
5
970
167,583
Effluent Avg (ng/l)
1 1 ,837
17 (ND)
37 (ND)
259
250 (ND)
65
2(ND)
169
1,287
Removal (%)
68.56
23.77
88.33
99.08
39.69
97.05
57.45
82.55
99.23
ND = Not detected
Table 6-4. Selective Metals Precipitation (Solid Metals Recovery) System Performance
Data for CWT QID 130
Parameter
Copper
Lead
Zinc
Influent Avg (|ig/l)
4,228,071
487,786
7,196,571
Effluent Avg (|j,g/l)
19,880
7,334
57,218
Removal (%)
99.53
98.50
99.20
6-7
-------
Table 6-5. Selective Metals Precipitation (Liquid Metals Recovery) System
Performance Data for CWT QID 130
Parameter
Chromium
Copper
Nickel
Silver
Minimum Batch
Removal (%)
(103.39)
28.01
93.95
(4.69)
Maximum Batch
Removal (%)
93.34
97.85
99.99
99.87
Average Batch
Removal (%)
26.70
66.08
97.73
55.35
Table 6-6. Secondary Precipitation System Performance Data for CWT QID 130
Parameter
Aluminum
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Silver
Zinc
Influent Avg (|j,g/l)
7,679
1,500
21 1 ,924
412,750
3,119
2,346
19
48,883
280
28,949
Effluent Avg (|ig/l)
337
101
690
970
308
61
1
1,060
4(ND)
845
Removal (%)
95.61
93.25
99.67
99.77
90.14
97.40
93.49
97.83
98.57
97.08
ND = Not detected
6-8
-------
Table 6-7. Tertiary Precipitation System Performance Data for CWT QID 130
Parameter
Aluminum
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Zinc
Influent Avg (u.g/1)
337
101
690
970
308
61
1
1,060
845
Effluent Avg (|j.g/l)
97
82
37
145
50
12
0.20 (ND)
1,251
167
Removal (%)
71.32
18.85
94.63
85.06
83.75
80.96
83.87
(18.07)
80.29
Table 6-8. Overall Metals Precipitation System Performance Data for CWT QID 130
Parameter
Aluminum
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Silver
Zinc
Influent Avg (p.g/1)
534,585
129,687
585,899
2,927,792
244,667
45,274
75
510,184
757
3,601,529
Effluent Avg (ng/l)
97
82
37
145
50
12
0.20 (ND)
1 ,251
4(ND)
167
Removal (%)
99.98
99.94
99.99
99.99
99.98
99.97
99.73
99.75
99.47
99.99
ND = Not detected
6-9
-------
6.1.2
Clarification
6.1.2.1
Technology Description
Clarification systems provide continuous, low-cost separation and removal of
suspended solids from water by the use of gravity. Clarification is used to remove
particulates, flocculated impurities, and precipitates. These systems typically follow
wastewater treatment processes which generate suspended solids, such as chemical
precipitation and biological treatment.
Clarification units are often preceded by a flocculation step to promote settling.
The flocculation process involves the addition of a treatment chemical, or flocculant, to
the wastewater. There are three different types of flocculants: inorganic electrolytes,
natural organic polymers, and synthetic polyelectrolytes. The flocculant is rapidly mixed
with the wastewater to disperse it uniformly. The duration of the rapid mix step is very
short, usually about one to two minutes. Slow and moderate mixing is provided to allow
the particles to agglomerate into larger, heavier, more settleable particles.
In the clarifier, the wastewater is allowed to flow slowly and uniformly, permitting
the solids more dense than water to settle to the bottom. The clarified wastewater is
discharged by flowing from the top of the clarifier over a weir. Conventional clarifiers
typically consist of a circular or rectangular tank. There are more specialized types of
clarifiers which incorporate tubes, plates, or lamellar networks to increase the settling
area. The sludge which accumulates at the bottom is periodically removed and must be
dewatered and disposed. A circular clarification system is illustrated in Figure 6-2.
6.1.2.2
Treatment Performance
According to the WTI Questionnaire data base, there are 35
clarification/flocculation systems in operation in the CWT Industry. CWT QID 105, which
was sampled by EPA during this rulemaking project, employs a clarifier which treats the
wastewater from hydroxide metals precipitation. This clarifier reduces an influent stream
6-10
-------
Skimming Scraper
Overflow
Influent
Effluent
Skimmings Removal
Sludge Removal
Figure 6-2. Clarification System Diagram
6-11
-------
of approximately 40,000 mg/l TSS (four percent solids) to an effluent of 500 mg/l. The
collected sludge TSS concentration is about 200,000 mg/l or 20 percent solids.
6.1.3
Plate and Frame Pressure Filtration
6.1.3.1
Technology Description
Plate and frame pressure filtration systems are used for the removal of solids from
waste streams. The liquid stream plate and frame pressure filtration system is identical
to the system used for the sludge stream (Subsection 6.4.1) with the exception of a lower
solids level in the influent stream. The same equipment is used for both applications, with
the difference being in the sizing of the sludge and liquid units. A plate and frame filter
press is shown in Figure 6-3.
A plate and frame filter press consists of a number of filter plates or trays
connected to a frame and pressed together between a fixed end and a moving end. Filter
cloth is mounted on the face of each plate. The sludge is pumped into the unit under
pressure while the plates are pressed together. The solids are retained in the cavities
of the filter press and begin to attach to the filter cloth until a cake is formed. The water,
or filtrate passes through the filter cloth and is discharged from a drainage port in the
bottom of the press. The sludge influent is pumped into the system until the cavities are
filled. Pressure is applied to the plates until the flow of filtrate stops.
At the end of the cycle, the pressure is released and the plates are separated.
The filter cake drops into a hopper below the press. The filter cake can then be disposed
in a landfill. The filter cloth is washed before the next cycle begins.
The key advantage of plate and frame pressure filtration is that it can produce a
drier filter cake than is possible with the other methods of sludge dewatering. The batch
operation of the plate and frame filter press makes it a practical choice for the filtration
of a batch chemical precipitation process effluent. Therefore, it is well-suited for use in
the CWT Industry. However, its batch operating mode results in greater operating labor
requirements.
6-12
-------
Fixed End
Sludge
Influent
Filtrate
Filter Cloth
Filter Cake
Applied
< Force
Plate Assembly
Figure 6-3. Plate and Frame Pressure Filtration System Diagram
6-13
-------
6.1.3.2
Treatment Performance
Respondents to the WTI Questionnaire reported that 34 plate and frame filter
presses (treating liquid and sludge streams) are in operation in the CWT Industry. In a
typical plate and frame pressure filtration unit, the filter cake has a dry solids content
between 30 and 50 percent.
6.1.4
Emulsion Breaking
6.1.4.1
Technology Description
Emulsion breaking is used to treat emulsified oil/water mixtures. An emulsion, by
definition, is either stable or unstable. A stable emulsion is one where the droplets of the
dispersed phase are so small that settling and coalescence would occur very slowly or
not at all. An unstable emulsion, or dispersion, settles very rapidly and does not require
treatment to break the emulsion. Stable emulsions .are often intentionally formed by
chemical addition to stabilize the oil mixture for a specific application. Some examples
of stable emulsified oils are coolants, lubricants, and antioxidants. •
Emulsion breaking is achieved by the addition of chemicals and/or heat to the
waste oil mixture. The most commonly-used method of emulsion breaking is acid-
cracking with or without heat addition. Sulfuric or hydrochloric acid is added to the tank
containing the oil mixture until the pH reaches 1 or 2. A coagulant is also added. The
tank contents are agitated for mixing. After the emulsion bond is broken, the oil residue
is allowed to float to the top of the tank. At this point, heat (100 to 150° F) may be
applied to speed the separation process. The oil is then skimmed off by mechanical
means, or the water is decanted from the bottom of the tank. The oil residue is then
further processed or disposed. A diagram of an emulsion breaking system is presented
in Rgure 6-4.
6-14
-------
Chemical
Addition
Wastewater
Influent
T.
" r ->"'** ~
-. f < ',
„ Mixing „
Tanfe
•• ^ v fff
V.V.*.
jjf
r
Oil
Residue
Sludge
Treated
Effluent
Figure 6-4. Emulsion Breaking System Diagram
6-15
-------
An advantage of the emulsion breaking process is the high removals that are
possible. A disadvantage, however, is the high operating costs for treatment chemicals
and heat generation. One way to minimize operating costs is to pretreat the oil/water
mixture to physically separate any free oil that may be present before emulsion breaking
is performed.
6.1.4.2
Treatment Performance
Emulsion breaking is a highly effective treatment technology for separating oil from
water. Typically, emulsions of five to 10 percent oil can be reduced to about 0.01
percent. Emulsion breaking is a common process in the CWT Industry; it is used by
most of the facilities identified as belonging in the Oils Subcategory. As such, EPA has
concluded that it is the baseline, current performance technology for the Oils Subcategory
for those facilities that treat emulsified oily wastes.
6.1.5 Equalization
6.1.5.1 Technology Description
Waste treatment facilities often need to equalize wastes by holding them in a tank
for a certain period of time to get a stable waste stream which is easier to treat. In the
CWT Industry, equalization is frequently used to minimize the variability of incoming
wastes prior to certain treatment operations. Equalization is found at facilities identified
in all of the CWT subcategories.
The equalization tank serves many functions. The influent flow is equalized so that
the effluent is discharged to downstream processes at a uniform rate. This levels out the
effect of peak and minimum flows. Additionally, waste contaminants are blended together
to provide a more constant discharge to the treatment system. This is accomplished by
mixing smaller volumes of concentrated wastes with larger volumes at lower
concentrations. For example, the pH can be controlled to prevent fluctuations which
6-16
-------
could upset the efficiency of downstream treatment system units by mixing acid and
alkaline wastes in the equalization tank. Equalization tanks are usually equipped with
mixing where the dampening of pollutant concentrations is desired. An equalization
system is shown in Figure 6-5.
6.1.5.2
Treatment Performance
According to the WTI Questionnaire response data base, there are 81 equalization
systems in the CWT Industry. Of these, 36 are unstirred and 45 are stirred or aerated.
No performance data were obtained for these systems.
6.1.6 Air Stripping
6.1.6.1 Technology Description
Air stripping is an effective treatment method for removing dissolved volatile
organic compounds from wastewater. The removal is accomplished by passing high
volumes of air through the agitated wastewater stream. The process results in a
contaminated off-gas stream which, depending upon air emissions standards, usually
requires air pollution control equipment.
Stripping can performed in tanks or in spray or packed towers. Treatment in
packed towers is the most efficient application. The packing typically consists of plastic
rings or saddles. The two types of towers that are commonly-used, cross-flow and
countercurrent, differ in design only in the location of the air inlets. In the cross-flow
tower, the air is drawn through the sides for the total height of the packing. The
countercurrent tower draws the entire air flow from the bottom. The cross-flow towers
have been found to be more susceptible to scaling problems and are less efficient than
the countercurrent towers. A countercurrent air stripper is shown in Figure 6-6.
The driving force of the air stripping mass-transfer operation is the difference in
concentrations between the air and liquid streams. Pollutants are transferred from the
6-17
-------
Wastewater
Influent
D
CO
Equalization
Tank
r
[Equalized
Effluent
Figure 6-5. Equalization System Diagram
6-18
-------
Wastewater
Influent
Blower
Off-gas
Distributor
Support
Treated
Effluent
Figure 6-6. Air Stripping System Diagram
6-19
-------
more concentrated wastewater stream to the less concentrated air stream until equilibrium
is reached; this equilibrium relationship is known as Henry's Law. The strippability of a
pollutant is expressed as its Henry's Law Constant, which is a function of both its volatility
and solubility.
Air strippers are designed according to the strippability of the pollutants to be
removed. For evaluation purposes, the organic pollutants were divided into three general
strippability ranges (low, medium, and high) according to their Henry's Law Constants.
The low strippability group (Henry's Law Constants of 10"3 [mg/m3 air]/[mg/m3 water] and
lower) are not effectively removed. Pollutants in the medium (10~1 to 10"3) and high (10"1
and greater) groups are effectively stripped. Pollutants with lower Henry's law constants
require greater column height, more trays or packing material, greater pressure and
temperature, and more frequent cleaning than pollutants with a higher strippability.
The air stripping process is adversely affected by low temperatures. Air strippers
experience lower efficiencies at lower temperatures, with the possibility of freezing within
the tower. For this reason, depending on the location of the tower, it may be necessary
to preheat the wastewater and the air feed streams. The column and packing materials
must be cleaned regularly to ensure that low effluent levels are attained.
6.1.6.2
Treatment Performance
Air stripping has proved to be an effective process in the removal of volatile
pollutants from wastewater. It is generally limited to influent concentrations of less than
100 mg/l organics. Well-designed and operated systems can achieve over 99 percent
removals.
One facility in the CWT Industry uses an air stripper to treat an organic-bearing
waste stream. This operation at CWT QID 059 was sampled by EPA, and these results
are presented in Table 6-9. The highly volatile constituent toluene had an average
influent concentration of 551 |ig/l and an effluent level of 10 ng/j (98.2 percent removal).
The pollutant 1,2-dichloroethane had an average influent level of 2,211 \ig/\ and an
effluent level of 10 \ig/\ (99.6 percent removal).
6-20
-------
Table 6-9. Air Stripping System Performance Data
Parameter
1 ,1 ,2-Trichloroethane
1 ,2-Dichloroethane
Chloroform
Methylene Chloride
Tetrachloroethene
Tetrachloromethane
Toluene
Trans-1 ,2-dichloroethene
Trichloroethene
Vinyl Chloride
Influent
Avg
(WO
2,481
2,736
11,615
32,217
6,973
5,527
551
2,211
9,332
555
Stripper #1
Effluent
Avg frig/l)
95
37
50
98
8
40
10 (ND)
16
41
10 (ND)
Stripper #2
Effluent
Avg (|ig/l)
19
29
30
385
12
12
10 (ND)
10 (ND)
22
10 (ND)
Removal (%)
(Influent to
Stripper #2)
99.24
98.93
99.75
98.80
99.83
99.79
98.18
99.55
99.76
98.20
ND = Not detected
6.1.7
Multi-media Filtration
6.1.7.1
Technology Description
Multi-media, or granular bed, filtration is used for achieving supplemental removal
of residual suspended solids from the effluent of chemical and biological treatment
processes. In granular bed filtration, the wastewater stream is sent through a bed
containing one or more layers of different granular materials. The solids are retained in
the voids between the media particles while the wastewater passes through the bed.
Typical media used in granular bed filters include anthracite coal, sand, and garnet.
These media can be used alone, such as in sand filtration, or in a multi-media
combination. Multi-media filters are designed such that the individual layers of media
6-21
-------
remain fairly discrete. This is accomplished by selecting appropriate filter loading rates,
media grain size, and bed density.
A multi-media filter operates with the finer, denser media at the bottom and the
coarser, less dense media at the top. A common arrangement is garnet at the bottom
of the bed, sand, in the.middle,,and anthracite coal at the top. Some mixing of these
layers occurs and is anticipated. During filtration, the removal of the suspended solids
is accomplished by a complex process involving one or more mechanisms, such as
straining, sedimentation, interception, impaction, and adsorption. The medium size is the
principal characteristic that affects the filtration operation. If the medium is too small,
much of the driving force will be wasted in overcoming the frictional resistance of the filter
bed. If the medium is too large, small particles will travel through the bed, preventing
optimum filtration.
The flow pattern of multi-media filters is usually top-to-bottom. Upflow filters,
horizontal filters, and biflow filters are also used. A top-to-bottom multi-media filter is
represented in Figure 6-7. The classic multi-media filter operates by gravity; however,
pressure filters are occasionally used.
The complete filtration process involves two phases: filtration and backwashing.
As the filter becomes filled with trapped solids, the efficiency of the filtration process falls
off. Head loss is a measure of solids trapped in the filter. As the head loss across the
filter bed increases to a limiting value, the end of the filter run is reached and the filter
must be backwashed to remove the suspended solids in the bed. During backwashing,
the flow through the filter is reversed so that the solids trapped in the media are dislodged
and can exit the filter. The bed may also be agitated with air to aid in solids removal.
The backwash water is then recycled back into the wastewater feed stream.
An important feature in filtration and backwashing is the underdrain. The
underdrain is the support structure for the filtration bed. The underdrain provides an area
for the accumulation of the filtered water without it being clogged from the filtered solids
or the media particles. During backwash, the underdrain provides even flow distribution
over the bed.
6-22
-------
Coarse Media-
Finer Media
Finest Media
Support
Underdrain Chamber
Wastewater Influent
Backwash
Coat
Silica Sand
Backwash
Treated Effluent
Figure 6-7. Multi-Media Filtration System Diagram
6-23
-------
6.1.7.2
Treatment Performance
Respondents to the WTI Questionnaire report that there are 10 sand filters and 9
multi-media filters in use in the CWT Industry. A multi-media filter, installed following a
biological treatment system at CWT QID 059, was sampled by EPA for this project. The
results of this sampling show that the average TSS concentration was reduced from 1,164
to 198 mg/l, providing a 83 percent removal. This reduced the BOD5 of the waste stream
from 17,622 to 1,700 mg/l, or by 90 percent. The COD was reduced from 53,451 to
2,400 mg/l, or by 96 percent.
6.1.8 Carbon Adsorption
6.1.8.1 Technology Description
Activated carbon adsorption is a demonstrated treatment technology for the
removal of organic pollutants from wastewater. Most applications use granular activated
carbon (GAG) in column reactors. Sometimes powdered activated carbon (PAC) is used
alone or in conjunction with another process, such as biological treatment. However,
GAG is the more commonly-used method; a diagram of a downflow fixed-bed GAG
system is presented in Figure 6-8.
The mechanism of adsorption is a combination of physical, chemical, and
electrostatic interactions between the activated carbon and the adsorbate, although the
attraction is primarily physical. Activated carbon can be made from many carbonaceous
sources including coal, coke, peat, wood, and coconut shells.
The key design parameter is adsorption capacity; this is a measurement of the
mass of contaminant adsorbed per unit mass of carbon, and is a function of the
compound being adsorbed, the type of carbon used, and the process design and
operating conditions. In general, the adsorption capacity is inversely proportional to the
adsorbate solubility. Nonpolar, high molecular weight organics with low solubility are
readily adsorbed. Polar, low molecular weight organics with high solubilities are more
6-24
-------
Fresh
Carbon
Fill
Collector/
Distributor
Spent
Carbon
Discharge
Wastewater
Influent
Backwash
Backwash
Treated
Effluent
Figure 6-8. Carbon Adsorption System Diagram
6-25
-------
poorly adsorbed. Competitive adsorption of other compounds has an effect on
adsorption. The carbon may preferentially adsorb one compound over another; this
competition could result in an adsorbed compound being desorbed from the carbon.
In a fixed-bed system, the pollutants are removed in increasing amounts as the
wastewater flows through the bed. In the upper area of the bed, the pollutants are rapidly
adsorbed. As more wastewater passes through the bed, this rapid adsorption zone
increases until it reaches the bottom of the bed. At this point, all of the available
adsorption sites are filled and the carbon is said to be exhausted. This condition can be
detected by an increase in the effluent pollutant concentration, and is called breakthrough.
GAG systems are usually comprised of several beds operated in series. This
design allows the first bed to go to exhaustion, while the other beds still have the capacity
to treat to an acceptable effluent quality. The carbon in the first bed is replaced, and the
second bed then becomes the lead bed. The GAG system piping is designed to allow
switching of bed order.
After the carbon is exhausted, it can be removed and regenerated. Usually heat
or steam is used to reverse the adsorption process. The light organic compounds are
volatilized and the heavy organic compounds are pyrolyzed. Spent carbon can also be
regenerated by contacting it with a solvent which dissolves the adsorbed pollutants.
Depending on system size and economics, some facilities may choose to dispose of the
spent carbon instead of regenerating it. For very large applications, an on-site
regeneration facility is sometimes constructed. For smaller applications, such as in the
CWT Industry, it is generally cost-effective to use a vendor service to deliver regenerated
carbon and remove the spent carbon. These vendors transport the spent carbon to their
centralized facilities for regeneration.
6.1.8.2 Treatment Performance
GAG adsorption is a widely-used wastewater treatment technology. Generally, the
COD of the waste stream can be reduced to less than 10 mg/l and the BOD to less than
2 mg/l. Removal efficiencies typically are in the range of 30 to 90 percent.
6-26
-------
According to the WT1 Questionnaire data base, there are 11 GAG applications in
the CWT Industry, treating both organic and oily waste streams. During this rulemaking
project, EPA sampled GAG systems at two Organics Subcategory facilities (CWT QID 059
and 090) and one Oils Subcategory facility (CWT QID 409). The data obtained from
these sampling efforts are presented in Tables 6-10 and 6-11.
As these results show, the sampled GAG systems did not perform as well as would
be expected. The COD reductions for three of the units were very low (0.2,1.5, and 23.8
percent), with the organics unit at QID 090 showing an increase in COD. In general, the
data for the unit at QID 090 show that many pollutants were not detected in the influent,
with very high analytical method detection levels. This makes it difficult to gauge the
performance for this unit on an individual pollutant basis. The COD data, however, show
that the overall performance of this unit is poor.
Poor GAG system performance can sometimes be attributed to competitive
adsorption between compounds in the waste stream. The pollutant methylene chloride
is often used as a measure of adsorption competition in a GAG system. This is because
it is readily adsorbed, and also desorbed by competitive compounds. The two oils units
showed very low methylene chloride removals of 18.8 and 49.4 percent; these beds may
have been subject to competitive adsorption effects. Conversely, the two organics units
demonstrated methylene removals of 87.0 and 89.5 percent; these numbers are in the
range of expected performance.
Another possible explanation for the poor performance of these units is the effect"
of the pollutant parameter oil and grease. The commonly-applied limit on oil and grease
loading to a GAG system is 10 mg/l. Oil and grease can coat the carbon particles,
thereby inhibiting the adsorption process. The two oils units and the organics unit at QID
090 had oil and grease loadings of 2,489, 49, and 76 mg/l, respectively. And, all three
of these systems showed oil and grease removals in the 60 to 85 percent range. This
indicates that the carbon beds may have been adversely effected by oil and grease
coating. The organics unit at QID 059 had a significantly lower oil and grease loading of
6 mg/l, which is below the 10 mg/l limit.
6-27
-------
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6-29
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Judging from the data collected, all of these GAG systems have TSS-related
problems. The commonly-used TSS loading limit to a GAG system is 50 mg/l. Solids can
plug the bed, resulting in excessive head loss. Both of the organics units had TSS
loadings (198 and 1,505 mg/i) in excess of this limit. The two oils units had TSS loadings
of 6 and 1 mg/l, well below the limit. However, the effluents from the oils units showed
increases in wastewater TSS concentrations; this is not expected, as well-operated GAG
units usually provide filtration.
All of the wastewaters from the sampled GAG systems showed increases in metals
concentrations. This may be a result of pH fluctuations within the units solubilizing metals
in the waste stream. Overall, the poor performance of the CWT GAG units may have
been caused by the inherent difficulty of operating carbon adsorption units for variable
waste streams.
6.1.9 Cyanide Destruction
6.1.9.1 Technology Description
Cyanide is a very toxic pollutant and, therefore, wastes containing cyanide are an
important environmental concern. The major portion of cyanide-bearing wastes are
produced by electroplating and metal finishing operations.
Three procedures used to perform cyanide destruction are discussed here; these
are alkaline chlorination with gaseous chlorine, alkaline chlorination with sodium
hypochlorite, and confidential business information (CBI) cyanide destruction. A diagram
of an alkaline chlorination system is presented in Figure 6-9. Alkaline chlorination can
destroy free dissolved hydrogen cyanide and can oxidize all simple and some complex
inorganic cyanides; however, it cannot effectively oxidize stable iron, copper, and nickel
cyanide complexes. The addition of heat to the alkaline chlorination process can facilitate
the more complete destruction of total cyanides.
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Caustic Feed
Wastewater
Influent .
Hypochlorite or Chlorine Feed
Figure 6-9. Cyanide Destruction System Diagram
Treated
Effluent
6-31
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In alkaline chlorination using gaseous chlorine, the oxidation process is
accomplished by direct addition of chlorine (CI2) as the oxidizer and sodium hydroxide
(NaOH) to maintain pH levels. The reaction mechanism is:
NaCN + CI2
2NaCNO + 3CL +
+ 2NaOH
6NaOH -
NaCNO + 2NaCI + HO
2NaHCO,
N2 + 6NaCI + 2H2O
The destruction of the cyanide takes place in two stages. The primary reaction is
the partial oxidation of the cyanide to cyanate at a pH above 9. In the second stage, the
pH is lowered to the 8 to 8.5 range for the oxidation of the cyanate to nitrogen and
carbon dioxide (as sodium bicarbonate). Each part of cyanide requires 2.73 parts of
chlorine to convert it to cyanate and an additional 4.1 parts ofchlorine to oxidize the
cyanate to nitrogen and carbon dioxide. At least 1.125 parts of sodium hydroxide is
required to control the pH with each stage.
Alkaline chlorination can also be conducted with sodium hypochlorite (NaOCI) as
the oxidizer. The oxidation of cyanide waste using sodium hypochlorite is similar to the
gaseous chlorine process. The reaction mechanism is:
NaCN + NaOCI -> NaCNO + NaCI
2NaCNO + SNaOCI
H2O
2NaHCO
N
SMaCI
In the first step, cyanide is oxidized to cyanate with the pH maintained in the range
of 9 to 11 . The second step oxidizes cyanate to carbon dioxide (as sodium bicarbonate)
and nitrogen at a controlled pH of 8.5. The amount of sodium hypochlorite and sodium
hydroxide needed to perform the oxidation is 7.5 parts and 8 parts per part of cyanide,
respectively.
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6.1.9.2
Treatment Performance
Respondents to the WTI Questionnaire report that there are 30 cyanide destruction
operations in-place in the CWT Industry. Of these, one is a thermal unit, one is the CBI
unit, and the rest are chemical reagent systems. During this project, EPA sampled one
of each of three cyanide treatment applications discussed in this subsection.
The alkaline chlorination process using gaseous chlorine was sampled at CWT QID
255. The average amenable cyanide concentration was reduced from 1,563 mg/l in the
influent to 64.7 mg/l in the effluent; this is a 96 percent removal. The average total
cyanide concentration was reduced from 1,721 mg/l in the influent to 354.9 mg/I in the
effluent; this equals a removal of 79 percent.
The sodium hypochlorite system, operated at an extended retention time, was
sampled at CWT QID 105. The average influent concentration of amenable cyanide was
1,548 mg/l; this was reduced by 82 percent to an effluent concentration of 276.1 mg/l.
The average influent concentration of total cyanide was 4,634 mg/i; this was reduced by
97 percent to 135.7 mg/l.
The CBI system was sampled at CWT QID 450. The average influent amenable
cyanide concentration was 3,317 mg/l and the effluent concentration was 8.2 mg/l, giving
a removal of 99.8 percent. This system reduced the average total cyanide concentration
from 6,467 to 10.4 mg/l; this is equal to a 99.8 percent removal.
6.1.10
Chromium Reduction
6.1.10.1 Technology Description
Reduction is a chemical reaction in which electrons are transferred from one
chemical to another. The main application of chemical reduction in wastewater treatment
is the reduction of hexavalent chromium to trivalent chromium. The reduction enables the
trivalent chromium to be precipitated from solution in conjunction with other metallic salts.
Sulfur dioxide, sodium bisulfite, sodium metabisulfite, and ferrous sulfate are strong
6-33
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reducing agents and are commonly used in industrial wastewater treatment applications.
Two types of chromium reduction are discussed here; these are reduction through the
use of sodium metabisulfite or sodium bisulfite and reduction through the use of gaseous
sulfur dioxide. A diagram of a chromium reduction system is presented in Figure 6-10.
These chromium reduction reactions are reactions are favored by a low pH of 2
to 3. At pH levels above 5, the reduction rate is slow. Oxidizing agents such as
dissolved oxygen and ferric iron interfere with the reduction process by consuming the
reducing agent. After the reduction process, the trivalent chromium is removed by
chemical precipitation.
Chromium reduction using sodium metabisulfite (Na2S2O5) and sodium bisulfite
(NaHSOg) are essentially similar. The mechanism for the reaction using sodium bisulfite
as the reducing agent is:
3NaHS03 + 3H2SO4
2H2CrO4
Cr2(SO4)3 + 3NaHSO4 + 5H2O
The hexavalent chromium is reduced to trivalent chromium using sodium
metabisulfite, with sulfuric acid used to lower the pH of the solution. The amount of
sodium metabisulfite needed to reduce the hexavalent chromium is reported as 3 parts
of sodium bisulfite per part of chromium, while the amount of sulfuric acid is 1 part per
part of chromium. The theoretical retention time is about 30 to 60 minutes.
A second process uses sulfur dioxide (SO2) as the reducing agent. The reaction
mechanism is:
3SO
3H2O
3H2SO3
3HSO
2H2Cr04
Cr2(SO4)3
5H2O
The hexavalent chromium is reduced to trivalent chromium using sulfur dioxide,
with sulfuric acid used to lower the pH of the solution. The amount of sulfur dioxide
needed to reduce the hexavalent chromium is reported as 1 .9 parts of sulfur dioxide per
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Sulfuric
Acid
Treatment
Chemical
pH Controller
Wastewater
Influent
Chemical Controller
Treated
Effluent
Reaction Tank
Figure 6-10.
Chromium Reduction System Diagram
6-35
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part of chromium, while the amount of sulfuric acid is 1 part per part of chromium. At a
pH of 3, the theoretical retention time is approximately 30 to 45 minutes.
6.1.10.2 Treatment Performance
According to the WTI Questionnaire response data base, chromium reduction
operations are conducted at 38 facilities in the CWT Industry. Of these 38 facilities, there
are four sulfur dioxide processes, 21 sodium bisulfite processes, and two sodium
metabisulfite processes. The remaining systems use various other reducing agents. As
part of this rulemaking project, EPA sampled one of each of the two types of reduction
processes discussed in this subsection.
For the chromium reduction process using sodium metabisulfite, sampling was
conducted at CWT QID 067. Only one batch was sampled at this facility; the influent
hexavalent chromium concentration was 10 |ig/l and the effluent concentration was 285
|ig/l. This shows an increase in hexavalent chromium concentration.
The chromium reduction process using sulfur dioxide was sampled at CWT QID
255. The average influent hexavalent chromium concentration was 940,253 ng/l; the
average effluent concentration was 30 |ig/l. This shows a reduction of 99.99 percent.
6.1.11 Electrolytic Recovery
6.1.11.1 Technology Description
Electrolytic recovery is used for the reclamation of metals from wastewater. It is
a common technology in the electroplating, mining, and electronic industries. It is used
for the recovery of copper, zinc, silver, cadmium, gold, and other heavy metals. Nickel
is poorly recovered due to its low standard potential.
The electrolytic recovery process uses an oxidation and reduction reaction.
Conductive electrodes (anodes and cathodes) are immersed in the metal-bearing
wastewater, with electrical energy applied to them. At the cathode, a metal ion is reduced
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to its elemental form (electron-consuming reaction). At the same time, gases such as
oxygen, hydrogen, or nitrogen form at the anode (electron-producing reaction). After the
metal coating on the cathode reaches a desired thickness, it may be removed and
recovered. The metal-plated cathode can then be used as the anode.
The equipment consists of an electrochemical reactor with electrodes, a gas-
venting system, recirculation pumps, and a power supply. A diagram of an electrolytic
recovery system is presented in Figure 6-11. Electrochemical reactors are typically
designed to produce high flow rates to increase the process efficiency.
A conventional electrolytic recovery system is effective for the recovery of metals
from relatively high-concentration wastewater. A specialized adaptation of electrolytic
recovery, called extended surface electrolysis, or ESE, operates effectively at lower
concentration levels. The ESE system uses a spiral cell containing a flow-through
cathode which has a very open structure and therefore a lower resistance to fluid flow.
This also provides a larger electrode surface. ESE systems are often used for the
recovery of copper, lead, mercury, silver, and gold.
6.1.11.2
Treatment Performance
Respondents to the WTI Questionnaire report that there are three electrolytic
recovery units in operation in the CWT Industry. No performance data were obtained for
these units.
6.1.12
Ion Exchange
6.1.12.1 Technology Description
Ion exchange is commonly used for the removal of heavy metals from relatively
low-concentration waste streams, such as electroplating wastewater. A key advantage
of the ion exchange process is that it allows for the recovery and reuse of the metal
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M+++2e-
Deposited
Metal
Porous Insulating Separator
2(
-------
contaminants. Ion exchange can also be designed to be selective to certain metals, and
can provide effective removal from wastewater having high background contaminant
levels. A disadvantage is that the resins can be fouled by some organic substances.
In an ion exchange system, the wastewater stream is passed through a bed of
resin. The resin contains bound groups of ionic charge on its surface, which are
exchanged for ions of the same charge in the wastewater. Resins are classified by type,
either cationic or anionic; the selection is dependent upon the wastewater contaminant
to be removed. A commonly-used resin is polystyrene copolymerized with
divinylbenzene.
The ion exchange process involves four steps: treatment, backwash, regeneration,
and rinse. During the treatment step, wastewater is passed through the resin bed. The
ion exchange process continues until pollutant breakthrough occurs. The resin is then
backwashed to reclassify the bed and to remove suspended solids. During the
regeneration step, the resin is contacted with either an acidic or alkaline solution
containing the ion originally present in the resin. This "reverses" the ion exchange
process and removes the metal ions from the resin. The bed is then rinsed to remove
residual regenerating solution. The resulting contaminated regenerating solution must be
further processed for reuse or disposal. Depending upon system size and economics,
some facilities choose to remove the spent resin and replace it with resin regenerated off-
site instead of regenerating the resin in-place.
Ion exchange equipment ranges from simple, inexpensive systems such as
domestic water softeners, to large, continuous industrial applications. The most
commonly-encountered industrial setup is a fixed-bed resin in a vertical column, where
the resin is regenerated in-place. A diagram of this type of system is presented in Figure
6-12. These systems can be designed so that the regenerant flow is concurrent or
countercurrent to the treatment flow. A countercurrent design, although more complex
to operate, provides a higher treatment efficiency. The beds can contain a single type
of resin for selective treatment, or the beds can be mixed to provide for more complete
deionization of the waste stream. Often, individual beds containing different resins are
arranged in series, which makes regeneration easier than in the mixed bed system.
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Wastewater
Influent
Used
Regenerant
Regenierant
Solution
Distributor
Support
Treated
Effluent
Figure 6-12.
Ion Exchange System Diagram
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6.1.12.2 Treatment Performance
r- "ij-
Ion exchange is very effective in the treatment of low-concentration metal-bearing
wastewater. A common application, chromic acid recovery, has a demonstrated
performance of 99.5 percent. Sampling data from the Metal Finishing Industry Study
showed a removal of copper from rinsewater of over 99 percent, and nickel removals
from 82 to 96 percent.
According to the WTI Questionnaire data base, one facility (CWT QID 255)
reported using the ion exchange process. No performance data were obtained for this
application.
6.1.13 Gravity Separation
6.1.13.1 Technology Description
Gravity separation is a simple, economical, and widely-used method for the
treatment of certain oily wastewater. It is effective in the removal of free and dispersed
oils and grease from oil/water mixtures. It is not applicable to the removal of emulsified
or soluble oils. Many facilities use gravity separation as a pretreatment step to remove
free oils prior to emulsion breaking treatment.
It is necessary to determine the nature of the oily waste stream to be treated
before a treatment technology can be selected. The primary factors to be considered
include: the concentration of oil in the waste stream and the size of the oil droplets; the
specific gravity of the oil compared to that of the wastewater; and the presence of
surfactants or chemical emulsifiers. Free, or dispersed oils are present in the wastewater
as discrete droplets with little or no water attached to them. These droplets will easily rise
to the surface of the oil/water mixture due to their low specific gravity. Large droplets rise
more readily than do small droplets.
Once the oil has risen to surface of the wastewater, it must be removed. This is
done mechanically via skimmers, baffles, plates, slotted pipes, or dip tubes. Because
6-41
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gravity separation is such a widely-used technology, there is an abundance of equipment
configurations available. A very common unit is the API (American Petroleum Institute)
separator, shown in Figure 6-13. This unit uses an overflow and an underflow baffle to
skim the floating oil layer from the surface. The resulting oilyTesidue from a gravity
separator must then be further processed or disposed.
6.1.13.2
Treatment Performance
Gravity separation is a demonstrated and effective method for removing free oils
and grease from wastewater. Depending upon the nature of the waste stream and the
equipment application, gravity separation with mechanical removal can remove over 99
percent of the free oil concentration. There are 18 gravity separation/skimming
applications and four plate/tube coalescers used in the CWT Industry. No performance
data were obtained for these systems.
6.1.14
Dissolved Air Flotation
6.1.14.1 Technology Description
Flotation is the process of influencing suspended particles to rise to the surface of
a tank where they can be collected and removed. Gas bubbles are introduced into the
wastewater and attach themselves to the particles, thereby reducing their specific gravity
and causing them to float. Flotation processes are utilized because they effectively
reduce the sedimentation times of suspended solids that have a specific gravity slightly
greater than 1.0.
Dissolved air flotation (DAF) is a one of several flotation techniques employed in
the treatment of wastewater. DAF is commonly used to extract free and dispersed oil and
grease from oily wastewater. For wastes containing emulsified oils, DAF applied after
emulsion breaking can improve treatment performance and shorten retention time. A flow
diagram of a DAF system is presented in Figure 6-14.
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Oil Retention
Baffle
o
Wastewater
Influent
Diffusion Device £!•
(vertical baffle) Skimmer
so
I I i I I I ^-^
^v
Scraper
Sludge
Hopper
Oil
Retention
Baffle
Treated
Effluent
Figure 6-13.
Gravity Separation System Diagram
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Float Removal Device
Treated
Effluent
Float
Wastewater
Influent
(Saturated
with Air)
^ Sludge (If Produced)
Figure 6-14. Dissolved Air Flotation System Diagram
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In DAF, air is injected into the wastewater stream while it is under pressure in a
pipeline. When the wastewater enters the flotation tank, the pressure is reduced and fine
air bubbles are released. These bubbles make contact with the suspended particles via
two separate mechanisms. If a flocculant is used, the rising air bubbles can be trapped
inside of the flocculated masses as they increase in size. The other type of contact is
adhesion, which is a result of the intermolecular attraction between the solid particle and
the air bubble.
The performance of the DAF unit relies on having adequate air bubbles present
to float all of the suspended solids to the surface of the tank. Partial flotation of solids
will occur if inadequate or excessive amounts of air bubbles are present. Therefore, the
air-to-solids ratio in the DAF unit determines the effluent quality and the solids
concentration in the float.
6.1.14.2
Treatment Performance
DAF technology is a well-demonstrated and an effective method of treating certain
oily wastewater. Respondents to the WTI Questionnaire report that there were five DAF
units in operation in the CWT Industry; no performance data were obtained for these
units.
6.2 BIOLOGICAL WASTEWATER TREATMENT TECHNOLOGIES
A portion of the CWT Industry accepts waste receipts containing organic pollutants,
which are often amenable to biological degradation. This subset of CWT facilities is
referred to as the Organics Subcategory.
Biological treatment systems use microbes which consume, and thereby destroy,
organic compounds as a food source. In addition to the carbon supplied by the organic
pollutants, these microbes also need energy and supplemental nutrients, such as nitrogen
and phosphorus, for growth. Aerobic microbes require oxygen to grow, whereas
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anaerobic microbes are destroyed by oxygen. An adaptive type of anaerobic microbe,
a facultative anaerobe, can grow with or without oxygen.
The success of biological treatment is also dependent on other factors, such as
the pH and temperature of the wastewater, the nature of the pollutants, the nutrient
requirements of the microbes, the presence of other inhibiting pollutants, and variations
in the feed stream loading. Certain compounds, such as heavy metals, are toxic to the
microorganisms and must be removed from the waste stream prior to biological treatment.
Load variations are a major concern, especially in the _CWT Industry, where waste
receipts vary overtime in both concentration and volume.
There are several adaptations of biological treatment. These adaptations differ in
three basic ways. First, a system can be aerobic, anaerobic, or facultative. Second, the
microorganisms can either be attached to a surface (as in a trickling filter), or be
unattached in a liquid suspension (as in an activated sludge system). The third difference
is whether the system operation is batch or continuous. In this industry, commercial
facilities which receive all of their wastes from off-site are restricted to consideration of
a batch process, which is not effected by waste load variations. Continuous biological
treatment systems, such as conventional activated sludge systems, are typically only
found at CWT facilities which receive their wastes from both on-site and off-site sources.
At many of these facilities, on-site manufacturing operations produce a relatively constant
waste stream that can support a continuous biological treatment system. The effect of
the off-site waste receipt variability is dampened by the presence of the on-site waste
stream.
According to the WTI Questionnaire data base, there are 12 activated sludge
systems (one with PAC addition), four aerobic systems, two facultative systems, one
denitrification system, one sequencing batch reactor (SBR), two biotowers, one surface
impoundment, and one land application system in the CWT Industry. There were no
anaerobic processes reported. The types of biological treatment processes which are
found in the CWT Industry and are discussed in this subsection are SBRs, biotowers, and
activated sludge systems.
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6.2.1
Sequencing Batch Reactors
6.2.1.1
Technology Description
A sequencing batch reactor (SBR) is a suspended growth system in which
wastewater is mixed with existing biological floe in an aeration basin. SBRs are unique
in that a single tank acts as an equalization tank, an aeration tank, and a clarifier. An
SBR is operated on a batch basis where the wastewater is mixed and aerated with the
biological floe for a specific period of time. The contents of the basin are allowed to settle
and the supernatant is decanted. The batch operation of an SBR makes it a feasible
biological treatment option for the CWT Industry, where the wastewater volumes and
characteristics are often highly variable. An SBR is shown in Figure 6-15.
The SBR has a four cycle process: fill, react, settle, and decant. The fill cycle has
three phases. The first phase, called static fill, introduces the wastewater to the system
under static conditions. This is the anaerobic period for biological phosphorus uptake.
The second phase of the fill cycle is where the wastewater is mixed to eliminate the scum
layer and prepare the microorganisms to receive oxygen. In the third phase, aeration is
added if aerobic conditions are desired. The react cycle is a time-dependent process that
continually mixes and aerates the wastewater while allowing the biological degradation
process to complete. The settling cycle utilizes a large surface area and a lower settling
rate to allow settling under quiescent conditions. During the decant cycle, approximately
one-third of the tank volume is decanted by subsurface withdrawal. This treated, clarified
effluent can then be further treated or discharged.
Excess biomass is periodically removed from the SBR when the quantity exceeds
that needed for operation. The sludge that is removed from the SBR can be reduced in
volume by thickening using a filter press. The sludge can be disposed in a landfill or
used as an agricultural fertilizer.
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Process
Cycle
Fill
React
Settle
Decant
Figure 6-15.
Sequencing Batch Reactor System Diagram
6-48
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6.2.1.2
Treatment Performance
According to the WTI Questionnaire respondents, one SBR was in operation in the
CWT Industry. EPA sampled'this application at CWT QID 059; the sampling results are
given in Table 6-12. This SBR reduced the average BOD5 concentration from 4,800 to
1,750 mg/l, for a 63.5 percent removal. The average nitrate-nitrite (as N) concentration
was reduced from 46.6 to 1.5 mg/l, for a 96.8 percent removal. The pollutants phenol
and carbon disulfide were reduced by 82 and 90.3 percent, respectively. The effluent
from this SBR was further treated in a carbon adsorption system.
Table 6-12. Sequencing Batch Reactor System Performance Data
Parameter
BOD5
COD
D-COD
TOG
2-Propanone
Ammonia as N
Carbon Disulfide
Nitrate-Nitrite as N
Pentachlorophenol
Phenol
Influent Avg (|ig/l)
4,800,000
6,525,000
53,500,000
2,225,000
10,608
992,500
158
46,550
949
2,000
Effluent Avg
(Hfl/l)
1 ,750,000
3,525,000
28,500,000
1 ,047,500
2,558
1 ,050,000
15
1,475
814
359
Removal (%)
63.54
45.98
46.73
52.92
75.88
(5.79)
90.32
96.83
14.24
82.03
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6.2.2
Biotowers
6.2.2.1
Technology Description
A biological treatment tower, or biotower, is an adaptation of biological treatment
which can be operated in a continuous or semi-continuous manner. A waste stream is
inoculated with bacteria and is passed through a packed reactor where biological
degradation occurs. The system is operated in a one-pass, flow-through configuration.
A diagram of a biotower is presented in Figure 6-16.
The biotower is a tank which is packed approximately two-thirds full with plastic
honeycomb waffles. These waffles provide an increased reaction surface area. An
inoculum is prepared which consists of a commercially-available freeze-dried bacteria
culture which has been rehydrated in water. A separate nutrient solution consisting of
ammonia and phosphorus is also prepared. The inoculum, nutrient solution, and
wastewater stream are fed into the bottom of the biotower. They are mixed and passed
up through the packing by air blowers. The treated effluent exits from the top of the
biotower.
After biological treatment, the effluent is sent to a separator where a flocculant is
added to aid in settling of the solids. The settled solids can then be dewatered and
disposed.
6.2.2.2
Treatment Performance
There are two biotowers in operation in the CWT Industry. One system treats a
waste stream which is primarily composed of leachate from an on-site landfill operation.
No performance data was obtained for this application. The other system at CWT QID
130 treats high-TOC wastewater from a metals recovery operation. EPA conducted
sampling at this facility during the CWT project; the biotower performance data that were
collected shows poor performance of the unit. No significant BOD5, COD, or TOG
removals were recorded during the sampling period.
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Inoculum
Nutrient
Solution
Wastewater
Influent
Treated
Effluent
Blower
Figure 6-16.
Biotower System Diagram
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6.2.3
Activated Sludge
6.2.3.1
Technology Description
The activated sludge process is a continuous-flow, aerobic biological process. The
microorganisms are in kept in suspension in the wastewater by mixing. This suspension
is called a mixed liquor. The microorganisms oxidize soluble and suspended organics to
carbon dioxide and water using oxygen. Types of activated sludge systems include
extended aeration, contact stabilization, high-rate modified aeration, step aeration, and
oxygen-activated sludge.
The principal design parameters for an activated sludge system are the mixed
liquor suspended solids (MLSS) of the system and the biological oxygen demand (BOD)
or chemical oxygen demand (COD) of the influent stream. The MLSS is a measure of
the quantity of microorganisms available for biodegradation, while the BOD or COD is a
measure of the organic loading to the system. Other key design parameters are the
detention time, the length of time that the wastewater must remain in contact with the
microorganisms to achieve the desired level of treatment, and F/M, the food-to-
microorganism ratio. F/M is the loading rate of BOD (or food) applied to the MLSS (or
microorganisms).
A diagram of a conventional activated sludge system is shown in Figure 6-17. The
system consists of an aeration basin, which is both aerated and mixed. An activated
sludge system is typically followed by a secondary clarifier to remove the suspended
solids. The resulting sludge from the secondary clarifier must then be dewatered and
disposed.
6.2.3.2
Treatment Performance
Respondents to the WTI Questionnaire report that there are 12 conventional
activated sludge systems in operation in the CWT Industry. These applications are
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Secondary
Clarification
Wastewater
Influent
Aeration
Basin
Treated
Effluent
Recycled Sludge
Waste
Excess
Sludge
Figure 6-17.
Activated Sludge System Diagram
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primarily found at facilities that treat on-site wastes in conjunction with off-site waste
receipts. No performance data were obtained for activated sludge systems.
6.3 ADVANCED WASTEWATER TREATMENT TECHNOLOGIES
The technologies presented here can be used as independent operations or as
advanced wastewater treatment processes to remove the pollutants remaining after
preliminary treatment. These operations are not as commonly-found as those discussed
in the preceding subsections.
6.3.1
Ultrafiltration
6.3.1.1
Technology Description
Ultrafiltration (UF) is used for the treatment of metal-finishing wastewater and oily
wastes. It can remove substances with molecular weights greater than 500, including
suspended solids, oil and grease, large organic molecules, and complexed heavy metals.
UF is used when the solute molecules are greater than ten times the size of the solvent
molecules, and are less than one-half micron. In the CWT Industry, UF is applied in the
treatment of oil/water emulsions. Oil/water emulsions contain both soluble and insoluble
oil. Typically the insoluble oil is removed from the emulsion by gravity separation assisted
by chemical addition. The soluble oil is then removed by UF. Oily wastewater containing
0.1 to 10 percent oil can be effectively treated by UF. A UF system is typically used as
an in-plant treatment technology, treating the oil/water emulsion prior to mixing with other
wastewater. A UF system is shown in Figure 6-18.
In UF, a semi-permeable microporous membrane performs the separation.
Wastewater is sent through membrane modules under pressure. Water and low-
molecular-weight solutes (for example, salts and some surfactants) pass through the
membrane and are removed as permeate. Emulsified oil and suspended solids are
rejected by the membrane and are removed as concentrate. The concentrate is
6-54
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Permeate (Treated Effluent)
Wastewater
Feed
Concentrate
Membrane Cross-section
Figure 6-18. Ultrafiltration System Diagram
6-55
-------
recirculated through the membrane unit until the flow of permeate drops. The permeate
can either be discharged or passed along to another treatment unit. The concentrate is
contained and held for further treatment or disposal.
The primary design consideration in UF is the membrane selection. A membrane
pore size is chosen based on the size of the contaminant particles targeted for removal.
Other design parameters to be considered are the solids concentration, viscosity, and
temperature of the feed stream, and the membrane permeability and thickness.
6.3.1.2
Treatment Performance
According to the WTI Questionnaire data base, there are three UF applications
in the CWT Industry. A UF system which treats oily wastewater at CWT QID 409 was
sampled by EPA; these results are presented in Table 6-13. This system removed 87.5
percent of the influent oil and grease and 99.9 percent of the TSS. Several organic and
metal pollutants were over 90 percent removed.
Table 6-13. Ultrafiltration System Performance Data
Parameter
Barium
2-Butanone
COD
Copper
Ethylbenzene
Lead
m-Xylene
n-Decane
Oil & Grease
TSS
Influent Avg (|ig/l)
2,790
39,276
54,976,900
14,101
12,220
9,930
19,585
55,561
19',926,350
6,388,400
Effluent Avg (|ig/l)
18
1,426
9,601 ,850
48
734
738
1,019
60
2,489,185
6,300
Removal (%)
99.36
96.37
82.53
99.66
94.00
92.57
94.80
99.89
87.51
99.90
6-56
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6.3.2
Reverse Osmosis
6.3.2.1
Technology Description
Reverse osmosis (RO) is a process for separating dissolved solids from=water. It
is commonly used to treat oily or metal-bearing wastewater. RO is applicable when the
solute molecules are approximately the same size as the solvent molecules. A semi-
permeable, microporous membrane and pressure are used to perform the separation.
RO systems are typically used as end-of-pipe polishing processes, prior to final discharge
of the treated wastewater.
Osmosis is the diffusion of a solvent (such as water) across a semi-permeable
membrane from a less concentrated solution into a more concentrated solution. In the
reverse osmosis process, pressure greater than the normal osmotic pressure is applied
to the more concentrated solution (the waste stream being treated), forcing the purified
water through the membrane and into the less concentrated stream which is called the
permeate. The low-molecular-weight solutes (for example, salts and some surfactants)
do not pass through the membrane. They are referred to as concentrate. The
concentrate is recirculated through the membrane unit until the flow of permeate drops.
The permeate can either be discharged or passed along to another treatment unit. The
concentrate is contained and held for further treatment or disposal. An RO system is
shown in Figure 6-19.
The performance of an RO system is dependent upon the dissolved solids
concentration and temperature of the feed stream, the applied pressure, and the type of
membrane selected. The key RO membrane properties to be considered are: selectivity
for water over ions, permeation rate, and durability. RO modules are available in various
membrane configurations, such as spiral-wound, tubular, hollow-fiber, and plate and
frame. In addition to the membrane modules, other capital items needed for an RO
installation include pumps, piping, instrumentation, and storage tanks. The major
operating cost is attributed to membrane replacement.
6-57
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Permeate (Treated Effluent)
Wastewater
Feed
Concentrate
Membrane Cross-section
Figure 6-19. Reverse Osmosis System Diagram
6-58
-------
6.3.2.2
Treatment Performance
Respondents to the WTI Questionnaire reported that there were three RO systems
in operation in the CWT Industry. A spiral-wound RO system treating an oily waste
stream at CWT QID 409 was sampled by EPA. The performance data obtained are
presented in Table 6-14. As the data show, this unit reduced the average oil and grease
concentration by 87.4 percent. Many of the metal pollutants were also effectively
removed, most notably aluminum, barium, calcium, chromium, cobalt, iron, magnesium,
manganese, nickel, and titanium, all of which were over 98 percent reduced.
Table 6-14. Reverse Osmosis System Performance Data
Parameter
Oil & Grease
Aluminum
Chromium
Cobalt
Iron
Lead
Magnesium
Manganese
Nickel
Zinc
Influent LTA (jig/l)
386,928
3,785
254
441
15,494
986
25,162
1,164
43,862
5,396
Effluent LTA (ng/l)
48,898
32
. 4(ND)
4
147
28
292
16
820
201
Removal (%)
87.36
99.15
98.43
99.09
99.05
97.16
98.84
98.63
98.13
96.28
LTA = Long-term average
ND = Not detected
6-59
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6.3.3
Lancy Filtration
6.3.3.1
Technology Description
The Lancy Sorption Filter System is a patented method for the continuous recovery
of heavy metals. Metals not removed by conventional waste treatment technologies can
be reduced to low concentrations by the Lancy sorption filtration process.
In the first stage of the Lancy filtration process, a soluble sulfide is added to the
wastewater in a reaction tank, converting most of the heavy metals to sulfides. From the
sulfide reaction tank, the solution is passed through the sorption filter media. Precipitated
metal sulfides and other suspended solids are filtered out. Any remaining soluble metals
are absorbed by the media. Excess soluble sulfides are also removed from the waste
stream.
The Lancy filtration process can reportedly reduce zinc, silver, copper, lead, and
cadmium to less than 0.05 mg/l and mercury to less than 2 (ig/l. In addition to the
effective removal of heavy metals, the system has a high solids filtration capacity and a
fully automatic, continuous operation. The system continuously recycles and reuses the
same filter media thereby saving on operating costs. The system can be installed with
a choice of media discharge - slurry or solid cake. The Lancy Sorption Filtration System
is shown in Figure 6-20.
6.3.3.2
Treatment Performance
A Lancy sorption filtration application at CWT QID 255 was sampled by EPA. This
unit is a polishing treatment for the effluent from a chemical precipitation, clarification, and
sand filtration treatment sequence. The data from this system are presented in Table 6-
15. These data show, that of the target metals, mercury was reduced to a concentration
of 2 jig/l. None of the other target metals, however, were reduced to concentrations as
low as 0.05 mg/l. In fact, many of the pollutant concentrations actually increased. This
6-60
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Wastewater
Influent
Recycle
Recycle
Tank
Treated ^^
Effluenr
Sorption
Filter
2
Media Dischar
Figure 6-20.
Lancy Filtration System Diagram
6-61
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poor performance may not be representative of the normal operation of this Lancy
application, as the unit was being tested during the sampling episode.
Table 6-15. Lancy Filtration System Performance Data
Parameter
TSS
Cadmium
Chromium
Copper
Hexavalent
Chromium
Lead
Manganese
Mercury
Silver
Zinc
Influent LTA (|ig/l)
638,900
120
461
1,382
73
631
1,396
15
142
4,047
Effluent LTA (|ig/l)
471 ,600
58
306
252
34
536
75
2
138
974
Removal (%)
26.19
51.67
33.62
81.77
53.42
15.05
94.63
86.67
2.82
75.93
6.3.4
LTA = Long-term average
Liquid Carbon Dioxide Extraction
6.3.4.1
Technology Description
Liquid carbon dioxide (CO2) extraction is used to extract and recover organic
contaminants from aqueous waste streams. A licensed, commercial application of this
technology is utilized in the CWT Industry under the name "Clean Extraction System
(CES)". The process can be effective in the removal of organic substances such as
hydrocarbons, aldehydes and ketones, nitriles, halogenated compounds, phenols, esters,
and heterocyclics. It is not effective in the removal of some compounds which are very
6-62
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water-soluble, such as ethylene glycol, and low molecular weight alcohols. It can provide
an alternative in the treatment of waste streams which historically have been incinerated.
The waste stream is fed into the top of a pressurized extraction tower containing
perforated plates, where it is contacted-with a countercurrent stream of liquefied CO2.
The organic contaminants in the waste stream are dissolved in the CO2; this extract is
then sent to a separator, where the CO2 is redistilled. The distilled CO2 vapor is
compressed and reused. The concentrated organics bottoms from the separator can then
be disposed or recovered. The treated wastewater stream which exits the extractor
(raffinate) is pressure-reduced, and may be further treated for residual organics removal
if necessary to meet discharge standards. A diagram of the CES is presented in Figure
6-21.
6.3.4.2 Treatment Performance
Pilot-scale operational data for a commercial CES unit are presented in Table 6-16.
This information was submitted to EPA by the CWT company which operates the system.
These data show high removals for a variety of organic compounds ranging up to 99.99
plus percent for methylene chloride. The commercial CWT CES unit was sampled by
EPA during this rulemaking effort. The percent removals achieved during the sampling
episode are also presented in Table 6-16. These removals are not as high as those
reported for the pilot-scale unit.
6.4 SLUDGE TREATMENT AND DISPOSAL
There are several waste treatment processes used in the CWT Industry which
generate a sludge. These processes include chemical precipitation of metals,
clarification, and biological treatment. Some oily waste treatment processes, such as
emulsion breaking and dissolved air flotation, also produce sludges. These sludges
typically contain between one and five percent solids. They require dewatering to
concentrate them and prepare them for transport and/or disposal.
6-63
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Extract
Vapor CO2
Feed
Makeup
CO,
Extractor
T
Water
Liquid CO2
T
Separator
Compressor
Organics
Figure 6-21. Liquid CO2 Extraction System Diagram
6-64
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1
8
c
CO
E
o
t
Q.
E
c
.0
•*J
CJ
2
s
o
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CO
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Average (nr
CO
lg
CO
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UJ ^"
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Parameter
CO
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en
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en en
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0
O
O
CD
Q
"Z.
c3"
0
o
in
CN
in
eri
en
o
o
o
Chloroform
CO
CO
Q
o
CM
CD'
CO
en
cri
en
o
o
o
in
CM
V
2-Dichloroetha
T-
cn
cq~
CD
a
o'
o
CM
O
co'
in in
CD h-
CO* CO*
en en
CD
5S
o
CO CO
**~"
Ethylbenzene
CD
CO*
CO
CM
CO*
T—
in
CO
CO
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en
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CD
0
0
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CO
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en
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2-Butanone
m
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CO
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CD
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Toluene
TJ
11
o
6-65
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Sludges are dewatered using pressure, which is caused by applied force, gravity,
vacuum, or centrifugal force. There are several widely-used, commercially-available
methods for sludge dewatering. The methods which are found in the CWT Industry and
are discussed in this subsection are: plate and frame pressure filtration, belt pressure
filtration, and vacuum filtration. A plate and frame filter press can produce the driest filter
cake of these three systems, followed by the belt press, and lastly, the vacuum filter.
In some instances, depending upon the nature of the sludge and the dewatering
process used, the sludge may first be stabilized, conditioned, and/or thickened prior to
dewatering. Certain sludges require stabilization (via chemical addition or biological
digestion) because they have an objectionable odor or are a health threat. Sludges
produced by the CWT Industry usually do not fall into this category. Sludge conditioning
is used to improve dewaterability; it can be accomplished via the addition of heat or
chemicals. Sludge thickening, or concentration, reduces the volume of sludge to be
dewatered and is accomplished by gravity settling, flotation, or centrifugation.
6.4.1
Plate and Frame Pressure Filtration
6.4.1.1
Technology Description
Plate and frame pressure filtration systems are used for the removal of solids from
waste streams. The sludge stream plate and frame pressure filtration system is identical
to the system used for the liquid stream (Subsection 6.1.3) with the exception of the
increase of higher solids level in the influent stream. The same equipment is used for
both applications, with the difference being in the sizing of the sludge and liquid units.
A plate and frame filter press is shown in Figure 6-22.
A plate and frame filter press consists of a number of filter plates or trays
connected to a frame and pressed together between a fixed end and a moving end. Filter
cloth is mounted on the face of each plate. The sludge is pumped into the unit under
pressure while the plates are pressed together. The solids are retained in the cavities
of the filter press and begin to attach to the filter cloth until a cake is formed. The water,
6-66
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Fixed End
Sludge
Influent
Filtrate •<—I
Filter Cloth
Filter Cake
Applied
xForce
Plate Assembly
Figure 6-22. Plate and Frame Pressure Filtration System Diagram
6-67
-------
or filtrate passes through the filter cloth and is discharged from a drainage port in the
bottom of the press. The sludge influent is pumped into the system until the cavities are
filled. Pressure is applied to the plates until the flow of filtrate stops.
At the end of the cycle, the pressure is released and the plates are separated.
The filter cake drops into a hopper below the press. The filter cake can then be disposed
in a landfill. The filter cloth is washed before the next cycle begins.
The key advantage of plate and frame pressure filtration is that it can produce a
drier filter cake than is possible with the other methods of sludge dewatering. It is well-
suited for use in the CWT Industry as it is a batch process. However, its batch operation
results in greater operating labor requirements.
6.4.1.2
Treatment Performance
Respondents to the WTI Questionnaire reported that 34 plate and frame filter
presses (treating liquid and sludge streams) are used in the CWT Industry. In a typical
plate and frame pressure filtration unit, the filter cake can exhibit a dry solids content
between 30 and 50 percent.
6.4.2
Belt Pressure Filtration
6.4.2.1
Technology Description
A belt pressure filtration system uses gravity followed by mechanical compression
and shear force to produce a sludge filter cake. Belt filter presses are continuous
systems which are commonly used to dewater biological treatment sludge. Most belt filter
installations are preceded by a flocculation step, where polymer is added to create a
sludge which has the strength to withstand being compressed between the belts without
being squeezed out. A typical belt filter press is illustrated in Figure 6-23.
During the press operation, the sludge stream is fed onto the first of two moving
cloth filter belts. The sludge is gravity-thickened as the water drains through the belt. As
6-68
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Sludge
Influent
Drainage Compression
Zone Zone
Wash Water
Shear
Zone
Filter
Cake
Figure 6-23.
Belt Pressure Filtration System Diagram
6-69
-------
the belt holding the sludge advances, it approaches a second moving belt. As the first
and second belts move closer together, the sludge is compressed between them. The
pressure is increased as the two belts travel together over and under a series of rollers.
The turning of the belts around the rollers shear the cake which furthers the dewatering
process. At the end of the roller pass, the belts move apart and the cake drops off. The
feed belt is washed before the sludge feed point. The dropped filter cake can then be
disposed.
The advantages of a belt filtration system are its lower labor requirements and
lower power consumption. On the minus side, belt filter presses produce a poorer quality
filtrate, and require a relatively large volume of belt wash water.
6.4.2.2
Treatment Performance
Typical belt filtration applications can dewater an undigested activated sludge to
a cake containing 15 to 25 percent solids. Heat-treated, digested sludges can be reduced
to a cake of up to 50 percent solids. According to the WTI Questionnaire data base,
there are six belt filter presses in-place in the CWT Industry; however, no performance
data were obtained for these systems.
6.4.3
Vacuum Filtration
6.4.3.1
Technology Description
A commonly-used process for dewatering sludge is rotary vacuum filtration. These
filters come in drum, coil, and belt configurations. The filter medium can be made of
cloth, coil springs, or wire-mesh fabric. A typical application is a rotary vacuum belt filter;
a diagram of this equipment is shown in Figure 6-24.
A continuous belt of filter fabric is wound around a horizontal rotating drum and
rollers. The drum is perforated and is connected to a vacuum. The drum is partially
immersed in a shallow tank containing the sludge. As the drum rotates, the vacuum
6-70
-------
Vacuum
Source
Filter Cake
Discharge
/
Media
Spray Wash
Figure 6-24.
Vacuum Filtration System Diagram
6-71
-------
which is applied to the inside of the drum draws the sludge onto the filter fabric. The
water from the sludge passes through the filter and into the drum, where it exits via a
discharge port. As the fabric leaves the drum and passes over the roller, the vacuum is
released. The filter cake drops off of the belt as it turns around the roller. The filter cake
can then be disposed.
Because vacuum filtration systems are relatively expensive to operate, they are
usually preceded by a thickening step which reduces the volume of sludge to be
dewatered. It is a continuous process and therefore requires less operator attention.
6.4.3.2
Treatment Performance
Vacuum filtration can reduce activated sludge to a cake containing 12 to 20
percent solids. Lime sludge can be reduced to a cake of 25 to 40 percent solids.
According to the WTI Questionnaire respondents, there are 10 vacuum filtration
installations in the CWT Industry. No performance data were obtained for these
installations.
6.4.4
Filter Cake Disposal
After a sludge is dewatered, the resultant filter cake must be disposed. The most
common method of filter cake management used in the CWT Industry is transport to an
off-site landfill for disposal. Other disposal options are incineration or land application.
Land application is usually restricted to biological treatment residuals.
6-72
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6.5 REFERENCES
Standard Methods for Examination of Water and Wastewater. 15th Edition, Washington
D. C.
Henricks, David, Inspectors Guide for Evaluation of Municipal Wastewater Treatment
Plants. Culp/Wesner/Culp, El Dorado Hills, CA, 1979.
Technical Practice Committee, Operation of Wastewater Treatment Plants, MOP/11,
Washington, D. C., 1976.
Clark, Viesman, and Hasner, Water Supply and Pollution Control. Harper and Row
Publishers, N.Y., N.Y., 1977.
Environmental Engineering Division, Computer Assisted Procedure For the Design and
Evaluation of Wastewater Treatment Systems (CAPDET), U. S. Army Engineer
Waterways Experiment Station, Vicksburg, Mississippi, 1981.
1991 Waste Treatment Industry Questionnaire. U. S. Environmental Protection Agency,
Washington, D. C.
Osmonics, Historical Perspective of Ultrafiltration and Reverse Osmosis Membrane
Development. Minnetonka, Minn., 1984.
Organic Chemicals and Plastics and Synthetic Fibers (OCPSR Cost Document. SAIC,
1987.
Effluent Guidelines Division, Development Document for Effluent Limitations Guidelines
& Standards for the Metal Finishing . Point Source Category, Office of Water Regulation
& Standards, U.S. EPA, Washington, DC, June 1983.
Effluent Guidelines Division, Development Document For Effluent Limitations Guidelines
and Standards for the Organic Chemicals Plastics and Synthetic Fibers (OCPSF),
Volume II, Point Source Category, EPA 440/1-87/009, Washington, D.C., October 1987.
Engineering News Record (ENR). McGraw-Hill Co., N.Y., N.Y., March 30, 1992.
Comparative Statistics of Industrial and Office Real Estate Markets, Society of Industrial
and Office Realtors of the National Association of Realtors, Washington, DC, 1990.
Effluent Guidelines Division, Development Document for Effluent Limitations Guidelines
& Standards for the Pesticides Industry., Point Source Category, EPA 440/1-85/079,
Washington, D.G., October, 1985.
6-73
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Peters, M., and Timmerhaus, K., Plant Design and Economics for Chemical Engineers,
McGraw-Hill, New York, N.Y., 1991.
Chemical Marketing Reporter. Schnell Publishing Company, Inc., N.Y,., N.Y., May 10,
1993.
Palmer, S.K., Breton, M.A., Nunno, T.J., Sullivan,. D.M., and Supprenaut, N.F.,
Metal/Cyanide Containing Wastes Treatment Technologies. Alliance Technical Corp.,
Bedford, MA, 1988.
Freeman, H.M., Standard Handbook of Hazardous Waste Treatment and Disposal, U.S.
EPA, McGraw-Hill, N.Y., N.Y., 1989.
Corbitt, Robert, Standard Handbook of Environmental Engineering. McGraw-Hill
Publishing Co., N.Y., N.Y., 1990.
Perry, H.. Chemical Engineers Handbook. 5th Edition. McGraw-Hill, N.Y., N.Y., 1973.
Development Document for BAT. Pretreatment Technology and New Source Performance
Technology for the Pesticide Chemical Industry. USEPA, 4/92.
Vestergaard, Clean Harbors Technology Corporation to SAIC - letter dated 10/13/93.
6-74
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SECTION 7
COST OF TREATMENT TECHNOLOGIES
This section presents the costs estimated for compliance with the CWT effluent
limitations guidelines and standards. Subsection 7.1 provides a general description of
how the individual treatment technology and regulatory option costs were developed. In
Subsections 7.2 through 7.5, the development of capital costs, operating and
maintenance (O & M) costs, and land requirements for each of the specific wastewater
and sludge treatment technologies is described in detail.
Additional compliance costs to be incurred by facilities, which are not dependent
upon a regulatory option or treatment technology, are presented in Subsection 7.6.
These additional items are retrofit costs, monitoring costs, RCRA permit modification
costs, and land costs.
7.1 COSTS DEVELOPMENT
7.1.1 Technology Costs
Cost information for the technologies selected is available from several sources.
The first source of information is the data base developed from the 1991 Waste
Treatment Industry (WTI) Questionnaire responses. A second source of information is
the Organic Chemical and Plastics and Synthetic Fibers (OCPSF) industrial effluent
limitations guidelines and standards development document, which utilizes the 1983 U.S.
Army Corps of Engineers' Computer Assisted Procedure for Design and Evaluation of
Wastewater Treatment Systems (CAPDET). A third source is engineering literature. The
fourth source of information is the CWT sampling facilities. The fifth source of information
is vendors' quotations. Vendors' recommendations were used extensively in the costing
of the various technologies. The data from the WTI Questionnaire contained a limited
amount of process cost information, and was used wherever possible.
7-1
-------
The total costs developed include the capital costs of the investment, annual O & M
costs, land requirement costs, sludge disposal costs, monitoring costs, RCRA permit
modification costs, and retrofit costs. All of the costs were either scaled up or scaled down
to 1989 dollars using the Engineering News Record (ENR) Construction Cost Index, as
1989 is the base year for the WTI Questionnaire.
The capital costs for the technologies are primarily based on vendors' quotations.
The equipment costs typically include the cost of the treatment unit and some ancillary
equipment associated with that technology. Investment costs added to the equipment cost
include piping, instrumentation and controls, pumps, installation, engineering, and
contingency. The standard factors used to estimate the capital costs are listed in
Table 7-1.
Table 7-1. Standard Capital Cost Factors
Factor
Equipment Cost
Installation
Piping
Instrumentation and Controls
Total Construction Cost (TCC)
Engineering
Contingency
Total Indirect Cost
Total Capital Cost
Capital Cost
Technology-Specific Cost
25 to 55 percent of equipment cost
31 to 66 percent of equipment cost
6 to 30 percent of equipment cost
Equipment + Installation + Piping +
Instrumentation and Controls
1 5 percent of TCC
15 percent of TCC
Engineering + Contingency
Total Construction Cost + Total Indirect Cost
The annual O & M costs for the various systems were derived from the vendors'
information or from engineering literature. The annual O & M cost is comprised of
energy, maintenance, taxes and insurance, labor, treatment chemicals (if needed), and
7-2
-------
residuals management (also if needed). The standard factors used to estimate the
O & M costs are listed in Table 7-2. All of the parameters used in costing the CWT
Industry are explained further in this section.
Table 7-2. Standard O & M Cost Factors
Factor
Maintenance
Taxes and Insurance
Labor
Electricity
Residuals Management
Granular Activated Carbon
Lime (Calcium Hydroxide)
Polymer
Sodium Hydroxide (100 percent
solution)
Sodium Hydroxide (50 percent
solution)
Sodium Hypochlorite
Sulfur Dioxide
Sulfuric Acid
Total O & M Cost
O & M Cost (1989 $)
4 percent of Total Capital Cost
2 percent of Total Capital Cost
$30,300 to $31 ,200 per man-year
$0.08 per kilowatt-hour
Technology-Specific Cost
$0.70 per pound
$57 per ton
$3.38 per pound
$560 per ton
$275 per ton
$0.64 per pound
$230 per ton
$80 per ton
Maintenance + Taxes and Insurance + Labor +
Electricity + Chemicals + Residuals
7-3
-------
7.1.2 Option Costs
Engineering costs were developed for each of the individual treatment technologies
which comprise the CWT regulatory options. These technology-specific costs, broken
down into capital, O & M, and land components, are explained further in this section.
To estimate the cost of an entire regulatory option, it is necessary to sum the costs
of the individual treatment technologies which make up that option. In some instances,
an option consists of only one treatment technology; for those cases, the option cost is
equal to the technology cost.
The CWT subcategory regulatory options are described in Table 7-3. The
treatment technologies included in each option are listed, and the subsections which
contain the corresponding cost information are indicated.
7.2 PHYSICAL/CHEMICAL/THERMAL WASTEWATER TREATMENT TECHNOLOGY
COSTS
7.2.1 Chemical Precipitation
Chemical precipitation systems are used to remove dissolved metals from
wastewater. Lime and caustic were selected as the precipitants because of their
effectiveness in removing dissolved metals. The chemical precipitation capital and O & M
costs were calculated for a flow rate range of 0.000001 to 5.0 MGD.
7.2.1.1
Chemical Precipitation - Metals Option 1
The CWT Metals Option 1 chemical precipitation system equipment consists of a
mixed reaction tank with pumps, a treatment chemical feed system, and an unmixed
wastewater holding tank. The system is operated on a batch basis, treating one batch
per day, five days per week. The average chemical precipitation batch duration reported
by respondents to the WTI Questionnaire was four hours. Therefore, a one batch per day
7-4
-------
Table 7-3. CWT Subcategory Options
Subcategory/Option
Metals 1
Metals 2
Metals 3
Metals - Hexavalent Chromium
Waste Pretreatment
Metals - Cyanide Waste
Pretreatment
Oils 2
Oils 3
Oils 4
Organics 1
Organics 2
Treatment Technology
Chemical Precipitation
Liquid Filtration or
Clarification/Sludge Filtration
Selective Metals Precipitation
Liquid Filtration
Secondary Precipitation
Liquid Filtration or
Clarification/Sludge Filtration
Metals Option 2 Technologies
Tertiary Precipitation
Clarification
pH Adjustment
Chromium Reduction using Sulfur
Dioxide
Cyanide Destruction at Special
Operating Conditions
Ultrafiltration
Oils Option 2 Technology
Carbon Adsorption
Reverse Osmosis
Oils Option 3 Technologies
Carbon Adsorption
Equalization
Air Stripping
Sequencing Batch Reactor
Multi-Media Filtration
Organics Option 1 Technologies
Carbon Adsorption
Subsection
7.2.1.1
7.2.3.1 or
7.2.2/7.5.1
7.2.1.2
7.2.3.2
7.2.1.3
7.2.3.2 or
7.2.2/7.5.1
(above)
7.2.1.4
7.2.2
7.2.1.4
7.2.9
7.2.8
7.4.1
(above)
7.2.7
7.4.2
(above)
7.2.7
7.2.4
7.2.5
7.3.1
7.2.6
(above)
7.2.7
7-5
-------
treatment schedule would provide sufficient time for the average facility to pump, treat,
and test its waste. A holding tank, equal to the daily waste volume, up to a maximum
size of 5,000 gallons (equivalent to one tank truck receipt), was prpvided to allow facilities
flexibility in managing waste receipts.
Total capital cost estimates were developed for the Metals Option 1 chemical
precipitation systems. For facilities with no chemical precipitation system in-place, the
components of the chemical precipitation system included the precipitation tank with a
mixer, pumps, and a feed system. In addition, the holding tank equal to the size of the
precipitation tank, up to 5,000 gallons, was also included. These cost estimates were
obtained from manufacturers' recommendations.
For facilities that already have a precipitation tank (treatment in-place), a capital
cost upgrade was determined; this consists of the cost of a holding tank only.
The resulting chemical precipitation capital cost and capital upgrade cost equations
for Metals Option 1 are presented as Equations 7-1 and 7-2, respectively.
ln(Y1) = 14.019 + 0.481 ln(X) - 0.00307(ln(X))2 (7-1)
In(Y1) = 10.671 - 0.083ln(X) - 0.032(ln(X))2 (7-2)
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989$).
where:
The O & M cost estimates for facilities with no treatment in-place were based on
estimated energy usage, maintenance, labor, taxes and insurance, and chemical usage
cost. The energy costs included electricity, lighting, and controls. The labor cost was
approximated at two hours per batch.
Chemical cost estimates were calculated based on stoichiometric, pH adjustment,
and buffer adjustment requirements. For facilities with no chemical precipitation in-place,
the stoichiometric requirements were based on the amount of chemicals required to
precipitate each of the metals from the Metals Subcategory average raw influent
7-6
-------
concentrations to Metals Option 1 levels. The chemicals used were lime at 75 percent
of the required removals and caustic at 25 percent of the required removals. The pH
adjustment and buffer adjustment requirements were estimated to be 50 percent of the
stoichiometric requirement. Finally, a 10 percent excess of chemical dosage was added.
The O & M cost equation for Metals Option 1 chemical precipitation is:
where:
ln(Y2)= 15.206 + 1.091ln(X) + 0.05(ln(X))2 (7-3)
X = Flow Rate (MGD) and
Y2 = O &M Cost (1989$).
An O & M upgrade cost was estimated for facilities with the chemical precipitation
treatment in-piace. It was assumed that these facilities already meet current Metals
Subcategory performance levels. The ratio of current-to-Metals Option 1 versus raw-to-
current levels is approximately 0.03, therefore, the energy, maintenance, and labor
components of the O & M upgrade cost were calculated at three percent of the total
O & M cost for these components. Taxes and insurance were based on the total capital
cost for the holding tank.
Chemical upgrade costs were calculated based on current-to-Metals Option 1
removals with no additional chemicals used for pH .adjustment and solution buffering, as
these steps would be part of the in-place treatment system. A 10 percent excess of
chemical dosage was added to the stoichiometric requirements.
The O & M upgrade cost equation for Metals Option 1 chemical precipitation is:
ln(Y2)= 11.702 + 1.006ln(X) + 0.044(ln(X))2
(7-4)
where:
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
7-7
-------
Land requirements for the chemical precipitation systems were estimated for
facilities with no chemical precipitation in-place and for facilities requiring only an upgrade.
The land requirements were obtained by adding a perimeter of 20 feet around the
equipment dimensions. These data were plotted and the land area equation was
determined. The land requirement and land requirement upgrade equations for metals
Option 1 chemical precipitation are presented as Equations 7-5 and 7-6, respectively.
ln(Y3) = -1.019 + 0.299In(X) + 0.015(ln(X))2
ln(Y3)= -2.866 - 0.023ln(X) - 0.006(ln(X))2
(7-5)
(7-6)
where:
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
7.2.1.2
Selective Metals Precipitation - Metals Option 2
The CWT Metals Option 2 selective metals precipitation system equipment consists
of four mixed reaction tanks, each sized for 25 percent of the total daily flow, with pumps
and treatment chemical feed systems. Four tanks are included to allow the facility to
segregate its wastes into smaller batches, thereby facilitating metals recovery and
avoiding interference with other incoming waste receipts. A four batch per day treatment
schedule was used, where the sum of four batch volumes equal the facility's daily
incoming waste volume.
Capital cost estimates forthe selective metals precipitation systems were estimated
using the same methodology as outlined for the Metals Option 1 chemical precipitation
systems. However, four precipitation tanks were costed, each tank sized to receive 25
percent of the overall flow.
The capital cost equation for Metals Option 2 selective metals precipitation is:
In(Y1) = 14.461 + 0.544ln(X) + 0.0000047(ln(X))2
7-8
(7-7)
-------
where:
X = Flow Rate (MGD) and
Y1 = Capital-Cost (1989 $).
The O & M cost estimates for the selective metals precipitation system for facilities
with no chemical precipitation treatment in-place were estimated using the same
methodology as outlined for Metals Option 1. However, since the proposed design
included four tanks instead of one, the labor cost was estimated at four times the labor cost
of the single chemical precipitation unit. Maintenance and taxes and insurance were
based on the total capital cost. Energy requirements were estimated the same as for the
Metals Option 1 chemical precipitation systems since energy is related to the flow of the
system.
Treatment chemical costs were estimated based on the same principles as for
Metals Option 1 chemical precipitation. The stoichiometric requirements were calculated
based on the Metals Subcategory average raw influent concentrations to Metals Option 1
removal levels. The chemicals used were caustic at 40 percent of the required removals
and lime at 60 percent of the required removals.
For facilities with chemical precipitation in-place, an O & M upgrade cost was
estimated using the same methodology as for Metals Option 1 with the exception of the
chemical costs. Chemical costs were estimated using a different methodology since these
facilities already meet Metals Option 1 levels. The in-place treatment system is assumed
to use a dosage ratio of 25 percent caustic and 75 percent lime to achieve the raw influent
to current performance removals. The selective metals precipitation upgrade requires
these facilities to change their existing dosage mix to 40 percent caustic and 60 percent
lime to reach current performance levels, then apply the full 40 percent/60 percent dosage
to further achieve the current performance to Metals Option 1 removals. The increase
in caustic cost (to increase from 25 percent to 40 percent) minus the lime credit (to
decrease from 75 percent to 60 percent) were accounted for in the in-place
treatment removals from raw to current levels. Metals Option 2 uses a higher percentage
7-9
-------
of caustic than does Metals Option 1 because the sludge resulting from caustic
precipitation facilitates metals recovery.
The O & M cost and O & M upgrade cost equations for Metals Option 2 selective
metals precipitation are presented as Equations 7-8 and 7-9, respectively.
ln(Y2) = 15.566 + 0.999ln(X) + 0.049(ln(X))2 (7-8)
ln(Y2) = 14.276 + 0.789ln(X) + 0.041 (ln(X))2 (7-9)
where:
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
The land requirements for selective metals precipitation were calculated based on
the equipment dimensions. The system dimensions were scaled up to represent the total
land required for the system plus peripherals (pumps, controls, access areas, etc.). The
rule-of-thumb used to scale the dimensions adds a 20-foot perimeter around the unit.
The land requirement equation for Metals Option 2 selective metals precipitation is:
where:
In(Y3) = -0.575 + 0.420In(X) + 0.025(ln(X))2
•
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
(7-10)
7.2.1.3
Secondary Precipitation - Metals Option 2
The CWT Metals Option 2 secondary precipitation system follows the selective
metals precipitation/filtration step. This equipment consists of a mixed reaction tank with
pumps and a treatment chemical feed system, sized for the full daily batch volume.
The capital cost estimates for the secondary precipitation treatment systems were
estimated using the same methodology as outlined for Metals Option 1. However, in this
7-10
-------
case, no costs were included for a holding tank. These cost estimates are for those
facilities that have no chemical precipitation, in-plaee.. For the facilities that already have
chemical precipitation in-place, the capital cost for the secondary precipitation treatment
systems were assumed to be zero. These in-place chemical precipitation systems would
serve as_ secondary precipitation systems after the installation of upstream selective
metals precipitation units.
The capital cost equation for Metals Option 2 secondary precipitation is:
where:
In (Y1) = 13.829 + 0.544ln(X) + 0.00000496(ln(X))2 (7-11)
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989 $).
O & M cost estimates were developed for the secondary precipitation treatment
systems for facilities with and without chemical precipitation in-place. For facilities with
no treatment in-place, the annual O & M costs were developed using the same
methodology used for Metals Option 1. However, the chemical cost estimates were
based on stoichiometric requirements only. Lime was used to precipitate the metals from
Metals Option 1 to Metals Option 2 levels with a 10 percent excess dosage factor.
For facilities with chemical precipitation in-place, an O & M upgrade cost was
calculated. The O & M upgrade cost assumed that all of the components of the annual
O & M cost except chemical costs were zero. The chemical costs are the same as
calculated for the full O & M costs.
The O & M cost and O & M upgrade cost equations for Metals Option 2 secondary
precipitation are presented as Equations 7-12 and 7-13, respectively.
In (Y2) = 11.684 + 0.477ln(X) + 0.024(ln(X))2
In (Y2) = 10.122 + 1.015ln(X) + 0.00151 (ln(X))2
(7-12)
(7-13)
7-11
-------
where:
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
Land requirements for the secondary precipitation treatment systems were
estimated by adding a perimeter of 20 feet around the equipment dimensions. The land
requirement equation for Metals Option 2 secondary precipitation is:
In (Y3) = -1.15 + 0.449ln(X) + 0.027(ln(X))2
(7-14)
where:
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
7.2.1.4
Tertiary Precipitation - Metals Option 3
The CWT Metals Option 3 tertiary precipitation system equipment consists of a
rapid mix tank and a pH adjustment tank (following Metals Option 3 clarification). The
wastewater is fed to the rapid mix neutralization tank where lime slurry is added to raise
the pH. Effluent from the neutralization tank then flows to the clarifier for solids removal.
The clarifier overflow goes to a pH adjustment tank where sulfuric acid is added to
achieve the desired final pH. The following discussion explains the development of the
cost estimates (i.e. capital, O & M, and land) for the rapid mix tank and the pH
adjustment tank. Cost estimates for the clarifier are discussed in Subsection 7.2.2 of this
report.
The capital cost estimates for the rapid mix tank were developed assuming one
tank with a continuous flow and a 15-minute detention time. The equipment cost includes
one tank, one agitator, and one lime feed system.
The capital cost estimates for the pH adjustment tank were developed assuming
continuous flow and a five-minute detention time. The equipment cost includes one tank,
one agitator, and one sulfuric acid feed system.
7-12
-------
The other components (i.e. piping, instrumentation and controls, etc.) of the total
capital cost for both the rapid mix and pH adjustment tank were estimated using the
Metals Option 1 methodology. The capital cost equations for the rapid mix and pH
adjustment tanks are presented as Equations 7-15 and 7-16, respectively.
ln(Y1) = 12.318 + 0.543ln(X) - 0.000179(ln(X))2 (7-15)
where:
ln(Y1) = 11.721 + 0.543ln(X) + 0.000139(ln(X))2 (7-16)
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989 $).
The O & M cost estimates for the rapid mix and pH adjustment tank were
estimated using the Metals Option 1 methodology. The labor requirements were
estimated at one man-hour per day.
Chemical costs for the rapid mix tank were estimated based on lime addition to
achieve the stoichiometric requirements for Metals Option 2 to Metals Option 3 removals
with a 10 percent excess. The chemical requirements for the pH adjustment tank were
estimated based on the addition of sulfuric acid to lower the pH from 11.0 to 9.0. The
O & M cost equations for the rapid mix tank and pH adjustment tank are presented as
Equations 7-17 and 7-18, respectively.
ln(Y2) = 10.011 + 0.385ln(X) + 0.022(ln(X))2
where:
ln(Y2) = 9.695 + 0.328ln(X) + 0.019(ln(X))2
X = Flow Rate (MGD) and
Y2 = O &M Cost (1989$).
(7-17)
(7-18)
7-13
-------
The land requirement equations for the rapid mix and pH adjustment tank are
presented as Equations 7-19 and 7-20, respectively.
ln(Y3) = -2.330 + 0.352ln(X) + 0.019(ln(X))2
ln(Y3) = -2.67 + 0.30ln(X) + 0.033(ln(X))2
where:
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
7.2.2 Clarification
(7-19)
(7-20)
Clarification systems provide continuous, low-cost separation and removal of
suspended solids from water. Clarification is used to remove particulates, flocculated
impurities, and precipitates. These clarification systems are equipped with a flocculation
unit and are costed with the addition of the flocculation step.
The costs for clarification systems were obtained from vendors. The influent total
suspended solids (TSS) design concentration used was 40,000 mg/l or four percent
solids. The effluent sludge TSS concentration was 200,000 mg/i or 20 percent solids.
The effluent overflow TSS concentration was 500 mg/l at a flow rate of 80 percent of the
influent flow. These parameters were taken from CWT QID 105. The clarification system
was evaluated for a flow rate range of 0.000001 to 1.0 MGD.
The clarification system includes a clarification unit, flocculation unit, pumps, motor,
foundation, and necessary accessories. The total construction cost includes the system
costs, installation, installed piping, and instrumentation and controls.
The O & M costs for all Metals Options were determined by energy usage,
maintenance, labor, flocculant cost, and taxes and insurance. Energy was divided into
cost for electricity, lighting, and controls. The labor requirements for Metals Options 1
and 2 were estimated between three hours per day (for the smaller systems) to four
hours per day (for the larger systems), while the labor requirement for Metals Option 3
7-14
-------
was one hour per day. The polymer dosage used in the flocculation step was 2.0 mg
polymer per liter of wastewater. This dosage was taken from the MP&M cost model.
The clarification capital cost equation for all the Metals Options is presented as
Equation 7-21. The clarification O & M cost equations for Metals Options 1 and 2 and
Metals Option 3 are presented as Equations 7-22 and 7-23, respectively.
where:
where:
ln(Y1) = 11.552 + 0.409Iri(X) + 0.020(ln(X))2
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989 $).
In(Y2) = 10.429 + 0.174ln(X) + 0.0091 (In(X))2
Y2 = O&M Cost (1989$).
(7-21)
(7-22)
ln(Y2) = 10.294 + 0.362ln(X) + 0.019(ln(X))2 (7-23)
where:
Y2 = O&M Cost (1989$).
A clarification system upgrade was calculated to estimate the increase in 0 & M
costs for facilities that already have a clarification system in-place. These facilities would
need to improve pollutant removals from their current performance levels to Metals
Option 1 levels. To determine the required increase from current performance to Metals
Option 1 levels, a comparison of the sum of the Metals Subcategory current performance
pollutant concentrations to Metals Option 1 levels versus the Metals Subcategory raw
influent pollutant concentrations to current performance levels was calculated. This
increase was determined to be three percent, as follows:
O & M Upgrade = Current - Metals Option 1 = 0.03 = 3%
Increase Raw - Current
(7-24)
7-15
-------
Therefore, in order for these facilities to perform at Metals Option 1 levels, an
O & M cost upgrade of three percent of the total O & M costs would be realized for each
facility. The O & M upgrade cost equation for Metals Option 1 clarification is:
ln(Y2) = 7.166 + 0.238ln(X) + 0.013(In(X))2 (7-25)
where:
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
To develop the clarification land requirements, the overall system dimensions were
scaled up to represent the total land required for the system plus peripherals (pumps,
controls, access areas, etc.). The equation relating the flow of the clarification system to
the land requirement for all Metals Options is:
ln(Y3) = -1.773 + 0.513ln(X) + 0.046(ln(X))2
(7-26)
where:
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
7.2.3 Plate and Frame Pressure Filtration - Liquid Stream
Pressure filtration systems are used for the removal of solids from waste streams.
These systems typically follow chemical precipitation or clarification.
7.2.3.1
Plate and Frame Filtration - Metals Option 1
The plate and frame pressure filtration system costs were estimated for a liquid
stream; this is the full effluent stream from a chemical precipitation process. The liquid
stream consists of 96 percent liquid and four percent (40,000 mg/l) solids. These influent
7-16
-------
parameters were taken from CWT QID 105. The capital and O & M costs were
calculated for a range of 0.000001 to 1.0 MGD.
The components of the plate and frame pressure filtration system include: filter
plates; filter cloth; hydraulic pumps; pneumatic booster pumps; control panel; connector
pipes; and support platform. Equipment and operational costs were obtained from
manufacturers' recommendations. The capital cost equation for Metals Option 1 liquid
filtration is:
where:
ln(Y1)= 14.826 + 1.089ln(X) + 0.050(ln(X))2 (7-27)
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989 $).
The O & M costs were based on estimated electricity usage, maintenance, labor,
taxes and insurance, and filter cake disposal costs. The labor requirements were
approximated at thirty minutes per cycle per filter press.
Filter cake disposal costs were derived from responses to the WTI Questionnaire.
The disposal cost was estimated at $0.74 per gallon of filter cake; this is based on the
cost of contract hauling and disposal in a Subtitle C or Subtitle D landfill. A more detailed
explanation of the filter cake disposal costs development is presented in Subsection 7.5.2.
To determine the total annual O & M costs for a plate and frame filtration system, the
filter cake disposal cost must be added to the other O & M costs. The O & M cost
equation for Metals Option 1 liquid filtration is:
ln(Y2) = 12.406 + 0.381 ln(X) + 0.014(ln(X))2
(7-28)
where:
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
7-17
-------
A pressure filtration system upgrade was calculated to estimate the increase in
O & M costs for facilities that already have a pressure filtration system in-place. These
facilities would need to improve pollutant removals from their current performance levels
to Metals Option 1 levels. To determine the percentage increase from current
performance to Metals Option 1 levels, the ratio of the current performance to Metals
Option 1 levels versus the raw data to current performance levels was calculated. This
incremental increase was determined to be three percent, as follows:
O & M Upgrade = Current - Metals Option 1 = 0.03 = 3%
Increase Raw - Current
(7-29)
Therefore, in order for the facilities to perform at Metals Option 1 levels, an O & M
cost upgrade of three percent of the total O & M costs (except for taxes and insurance,
which are a function of the capital cost) would be realized for each facility. The filter cake
disposal upgrade costs are presented in Subsection 7.5.2. The O & M upgrade cost
equation for Metals Option 1 liquid filtration is:
ln(Y2) = 8.707 + 0.333ln(X) + 0.012(ln(X))2 (7-30)
where:
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
The land requirements for the plate and frame pressure filtration systems were
calculated by adding a perimeter of 20 feet around the equipment dimensions. The land
requirement equation for Metals Option 1 liquid filtration is:
ln(Y3) = -1.971 + 0.281 ln(X) + 0.018(ln(X))2
(7-31)
where:
X = Flow Rate (MGD) and
Y3 e Land Requirement (Acres).
7-18
-------
7.2.3.2
Plate and Frame Filtration - MetalsOption 2
The plate and frame pressure filtration system liquid stream costs for Metals
Option 2 are based on the same parameters and are from the same vendors as Metals
Option 1. The capital and O & M costs were computed the same as for the Metals
Option 1 liquid filtration systems. The Metals Option 2 capital and O & M costs are based
on two pressure filtration units processing two batches per day. These units were sized
at 25 percent of the total liquid stream flow each.
The Metals Option 2 O & M costs parameters were similar to the Metals Option 1
parameters. The electricity costs were similar because electricity usage is based on
wastewater flow rate. The labor costs were scaled up by four to account for the two units
at two batches per day. The maintenance and taxes and insurance were based on the
Metals Option 2 capital costs. The filter cake disposal costs were the same as for Metals
Option 1 and are presented in Subsection 7.5.2. The total O & M costs for Metals Option 2
are calculated by adding the filter cake disposal costs to the O & M costs. The capital and
O & M cost equations for Metals Option 2 liquid filtration are presented as Equations 7-32
and 7-33, respectively.
where:
In(Y1) = 14.024 + 0.859ln(X) + 0.040(ln(X))2
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989 $).
ln(Y2) = 13.056 + 0.193In(X) + 0.00343(ln(X))2
(7-32)
(7-33)
where:
Y2 = O&M Cost (1989$).
The land requirements for the plate and frame pressure filtration systems were
calculated by adding a perimeter of 20 feet around the equipment dimensions for one
7-19
-------
system and doubling the area to account for the two systems. The land requirement
equation for Metals Option 2 liquid filtration is:
In(Y3) = -1.658 + 0.185ln(X) + 0.009(ln(X))2 (7-34)
where:
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
7.2.4 Equalization
Waste treatment facilities often need to equalize wastes by holding them in a tank
for a period of time to get a stable waste stream which is easier to treat. In the CWT
Industry, equalization is frequently used to minimize the variablity of incoming wastes.
The equalization cost estimates were obtained from OCPSF's use of the 1983
CAPDET program. The equalization process utilizes a mechanical aeration basin. The
following default design parameters were used:
Aerator mixing requirements = 0.03 hp per 1,000 gallons;
• Oxygen requirements = 15.0 mg/l per hour;
Dissolved oxygen in basin = 2.0 mg/l;
Depth of basin = 6.0 feet; and
• Detention time = 24 hours.
A detention time of 24 hours is appropriate, as this was the median equalization
detention time reported by respondents to the WTI Questionnaire. The range of
wastewater flows selected for these analyses was 0.001 to 5.0 MGD.
Capital costs were calculated based upon total project costs less: miscellaneous
nonconstruction costs, 201 planning costs, technical costs, land costs, interest during
construction, and laboratory costs. O & M costs were obtained directly from the initial
year O & M costs. The capital and O & M cost equations for the equalization systems
are presented as Equations 7-35 and 7-36, respectively.
ln(Y1) = 12.057 + 0.433ln(X) + 0.043(ln(X))2
7-20
(7-35)
-------
where:
X = Flow Rate (MGD) and ,
Y1 = Capital Cost (1989$).
ln(Y2) = 11.723 + 0.311ln(X) + 0.019(ln(X))2
(7-36)
where:
Y2 = O&M Cost (1989$).
The CAPDET program was used to develop land requirements for the equalization
systems. The requirements are scaled up to represent the total land required for the
system plus peripherals (pumps, controls, access areas, etc.). The equation relating the
flow of the equalization system to the land requirement is:
where:
ln(Y3) = -0.912 + 1.120ln(X) + 0.011(In(X))2
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
(7-37)
7.2.5 Air Stripping
Air stripping is an effective wastewater treatment method for removing dissolved
gases and highly volatile odorous compounds from wastewater streams by passing high
volumes of air through an agitated gas-water mixture.
The air stripping technology cost was based on removing medium volatile
pollutants. The medium volatile pollutant 1,2-dichloroethane was used for the calculations
with an influent level of 4,000 |ig/l and effluent level of 68 |ig/l. The equipment costs were
calculated for a flow rate range of 0.0001 to 1.0 MGD and were obtained from vendor
services. The air stripping unit costs included transfer pumps, control panels, blowers,
and ancillary equipment. Catalytic oxidizers were also included in the capital cost for air
pollution control purposes. The capital cost equation for air stripping systems is:
7-21
-------
where:
ln(Y1) = 12.899 + 0.486ln(X) + 0.031(ln(X))2 (7-38)
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989$).
The O & M costs were determined by electricity usage, maintenance, labor,
catalyst replacement, and taxes and insurance. The electricity usage for the air strippers
was determined by the amount of horsepower needed to operate the systems. The
electricity usage for the catalytic oxidizers was approximated at 50 percent of the
electricity used for the air strippers. The labor requirement for the air strippers was three
hours per day. The catalysts used in the catalytic oxidizer are precious metal catalysts
and their lifetime is approximately four years. Therefore, the catalyst beds are completely
replaced about every four years. The costs for replacing the spent catalysts were divided
by four to convert them to annual costs. The O & M cost equation for air stripping
systems is:
ln(Y2) = 10.865 + 0.298ln(X) + 0.021 (ln(X))2
(7-39)
where:
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
To develop land requirements for the air stripping and catalytic oxidizer systems,
the individual system dimensions were combined, and a 20-foot perimeter was added to
the plot. The dimensions of the air strippers, in terms of length and width, are very small
compared to the catalytic oxidizers. The equation relating the flow of the system to the
land requirement is:
ln(Y) = -2.207 + 0.536ln(X) + 0.042(ln(X))2
(7-40)
7-22
-------
where:
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
7.2.6 Multi-Media Filtration
Filtration is a proven technology for the removal of residual suspended solids from
wastewater. The media used in the CWT multi-media filtration process are sand and
anthracite coal, supported by gravel. Large particulate matter is captured by the coarse,
lighter media near the top of the filter bed. Flow controls are self-adjusting to regulate
treatment and backwash rates regardless of fluctuations in water pressure, thus helping
to prevent a loss of filter media from the tank.
To size the multi-media filtration systems, the design average influent total
suspended solids design concentration used was 165 mg/l. The design average effluent
total suspended solids concentration was 124 mg/l. These concentrations were taken
from the data for CWT QID 059. The system costs were calculated for a flow rate range
of 0.001 to 1.0 MGD and were obtained from vendor services.
The total capital costs for the multi-media filtration systems represent equipment
and installation costs. The total construction cost includes the costs of the filter,
instrumentation and controls, pumps, piping, and installation. The capital cost equation
for multi-media filtration systems is:
where:
ln(Y1) = 11.218 + 0.865ln(X) + 0.066(ln(X))2 (7-41)
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989 $).
The O & M costs include energy usage, maintenance, labor, and taxes and
insurance. Energy is the cost of electricity to run the pumps, lighting, and instrumentation
7-23
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and controls. The labor requirement for the multi-media filtration system was four hours
per day. The O & M cost equation for multi-media filtration systems is:
ln(Y2) = 11.290 + 0.580!n(X) + 0.057(ln(X))2
(7-42)
where:
Y2 = O&M Cost (1989$).
To develop land requirements for multi-media filtration systems, overall system
dimensions were provided by the vendor. The equation relating the flow of the system
to the land requirement is:
where:
ln(Y3) = -2.971 + 0.097ln(X) + 0.008(ln(X))2 (7-43)
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
7.2.7 Carbon Adsorption
Activated carbon adsorption is an effective treatment technology for the removal
of organic pollutants from wastewater. It is included in Oils Options 3 and 4 and Organics
Option 2. The considered application for the CWT Industry is granular activated carbon
(GAG) in column reactors. The equipment consists of two beds operated in series. This
configuration allows the beds to go to exhaustion and be replaced on a rotating basis.
The GAG capital costs are the same for all of the regulatory options considered. The
capital and O & M costs were calculated for a flow rate range of 0.00001 to 0.24 MGD.
The capital costs consist of the adsorber construction cost, initial carbon fill, freight, and
supervision. The GAG capital cost equation is:
ln(Y1) = 15.956 + 1.423ln(x) + 0.050(ln(X))2
(7-44)
7-24
-------
where:
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989$).
The O & M costs are primarily attributed to carbon usage. The key design
parameter is adsorption capacity; this is a measurement of the mass of pollutant
adsorbed per unit mass of carbon. For each regulatory option system, the pollutants of
concern and their associated removals were tabulated. Using the adsorption capacities,
the specific carbon requirements were calculated. The carbon usage for each option was
scaled down by one-third; this accounts for the series-bed design of the systems.
The total O & M cost components are electricity, maintenance, labor, freight, and
taxes and insurance, in addition to the carbon usage. The freight cost for shipping the
carbon is dependent upon the amount of carbon and the distance that it is shipped. The
average freight cost used is $3,000 per 20,000-pound shipment. Labor requirements are
three hours per day. The GAG O & M cost equations for Oils Option 3, Oils Option 4,
and Organics Option 2 are presented as Equations 7-45, 7-46, and 7-47, respectively.
ln(Y2) = 14.516 + 1.086ln(X) + 0.060(ln(X))2 (7-45)
ln(Y2) = 15.949 + 1.310In(X) + 0.068(ln(X))2 (7-46)
where:
ln(Y2) = 17.621 +1.455ln(X) + 0.067(ln(X))2 (7-47)
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
The land requirement estimates for the GAG systems are the same for all three
options. The equipment dimensions supplied by the vendor were used to determine the
land needed. A standard 20-foot perimeter was added to the equipment dimensions to
account for access, piping, and controls. The resultant land requirement equation is:
7-25
-------
ln(Y3) = -1.780 + 0.319ln(X) + 0.017(ln(X))2 (7-48)
where:
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
7.2.8 Cyanide Destruction
Cyanide destruction oxidation is capable of achieving removal efficiencies of 99
percent or greater and to the levels of detection. Chlorine is primarily used as the
oxidizing agent in this process, which is called alkaline chlorination, and can be utilized
in the elemental or hypochlorite form.
The capital and O & M costs curves for cyanide destruction systems with special
operating conditions were obtained from vendor services. The concentration used for
influent amenable cyanide was 1,548,000 |j.g/l and for total cyanides was 4,633,710 jig/l.
The effluent for these pollutants was 276,106 |o.g/l for amenable cyanides and 135,661
p.g/1 for total cyanides. These rates show a removal of 82 percent for amenable cyanide
and 97 percent for total cyanides. These concentrations were taken from the sampling
data for CWTQID 105.
The oxidation of cyanide waste using sodium hypochlorite is a two step process.
In the first step, cyanide is oxidized to cyanate in the presence of hypochlorite and
sodium hydroxide with the base required to maintain a pH range of 9 to 11. The second
step oxidizes cyanate to carbon dioxide and nitrogen at a controlled pH of 8.5. The
amounts of sodium hypochlorite and sodium hydroxide needed to perform the oxidation
are 7.5 parts and 8.0 parts per part of cyanide, respectively. At these levels, the total
reduction occurs at a retention time of 16 to 20 hours. The application of heat can
facilitate the more complete destruction of total cyanide. The system costs were
calculated on a batch volume range from 1.0 to 1,000,000 gallons per day and because
of the extended retention time, a basis of one batch per day is used.
The capital cost equation for the cyanide destruction system represents equipment
and installation costs. The equipment items include a two-stage reactor with a retention
7-26
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time of 16 hours, feed system and controls, pumps, piping, and foundation. The two-
stage reactor includes a covered tank, mixer, and containment tank. The total
construction cost includes the tank costs, instrumentation and controls, pumps, piping,
and installation. The capital cost equation is:
where:
ln(Y1) = 13.977 + 0.546In(X) + 0.0033(ln(X))2 (7-49)
X = Batch Size (MGD) and
Y1 = Capital Cost (1989 $).
The O & M costs were determined by energy usage, chemical costs, maintenance,
labor, and taxes and insurance. The labor requirement forthe cyanide destruction system
was three hours per day. The O & M cost equation is:
ln(Y2) = 18.237 + 1.318ln(X) + 0.04993(1 n(X))2 (7-50)
where:
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
The vendor information was used to develop land requirements for the cyanide
destruction systems with special operating conditions. The equation relating the flow of
the system to the land requirement is:
where:
ln(Y3) = -1.168 + 0.419ln(X) + 0.021 (ln(X))2
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
(7-51)
7-27
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7.2.9 Chromium Reduction
Reduction is a chemical reaction in which electrons are transferred from one
chemical to another; The main application of chemical reduction to the treatment of
wastewater is in the reduction of hexavalent chromium to trivalent chromium. The
reduction enables the trivalent chromium to be precipitated from solution in conjunction
with other metallic salts.
To develop the costs for chromium reduction systems using sulfur dioxide, costs
were obtained from vendors. The average influent hexavalent chromium design
concentration used was 752,204 jig/1; the maximum concentration was 3,300,000 |ig/l.
The average effluent concentration was 30 jig/1. These concentrations were taken from
the sampling data for CWT QID 255.
The hexavalent chromium is reduced to trivalent chromium using sulfur dioxide and
sulfuric acid. The sulfuric acid is used to lower the pH of the solution and the sulfur
dioxide is used for the reduction process. After the reduction process, the trivalent
chromium is then removed by precipitation. The amount of sulfur dioxide needed to
reduce the hexavalent chromium was reported as 1.9 parts of sulfur dioxide per part of
chromium, while the amount of sulfuric acid was 1.0 part per part of chromium. At these
levels, the total reduction occurs at a retention time of 45 to 60 minutes. The system
costs were calculated for a batch volume range from 1,000 gallons to 1,000,000 gallons
on a basis of two batches per day.
The capital cost equation forthe chromium reduction system represents equipment
and installation costs. The equipment items include a reduction reactor, feed system and
controls, pumps, piping, and foundation. The reactor includes a covered tank, mixer, and
containment tank. The total construction cost includes the tank costs, instrumentation and
controls, pumps, piping, and installation.
Capital costs for system upgrades were developed to estimate the incremental cost
required to install a new chemical feed mechanism on an existing chromium reduction
system that utilizes a treatment chemical other than sulfur dioxide. Fror the upgrade
7-28
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costs, the piping and instrumentation and controls equipment items were used to
determine the total construction cost.
The capital cost and capital upgrade cost equations are presented as Equations
7-52 and 7-53, respectively. -
ln(Y1) = 13.737 + O.GOOIn(X) (7-52)
ln(Y1) = 12.068 + 0.492ln(X) - 0.000496(ln(X))2 (7-53)
X = Volume per Day (MGD) and
Y1 = Capital Cost (1989 $).
where:
The O & M costs were determined by energy usage, chemical costs, maintenance,
labor, and taxes and insurance. The labor requirement for the chromium reduction
system was four hours per day.
O & M costs for system upgrades were developed to estimate the incremental cost
required to operate an existing chromium reduction system that utilizes a treatment
chemical, other than sulfur dioxide, that is a waste product for which a facility does not
incur a purchase cost. The chemical cost items were used to determine the total O & M
cost.
The O & M cost and O & M upgrade cost equations are presented as Equations
7-54 and 7-55, respectively.
ln(Y2) = 13.167 + 0.998ln(X) + 0.079(ln(X))2
where:
ln(Y2) = 13.123 + 1.365ln(X) + 0.059(ln(X))2
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
(7-54)
(7-55)
7-29
-------
To develop land requirements for chromium reduction systems, approximate
dimensions were calculated using the diameters of the systems. The land was calculated
by estimating the size for the reaction tank, storage tanks, and feed system. The
equation relating the flow of the system to the land requirement is:
where:
ln(Y3) = -1.303 + 0.185ln(X) - 0.036(ln(X))2
•
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
(7-56)
7.3 BIOLOGICAL WASTEWATER TREATMENT TECHNOLOGY COSTS
7.3.1 Sequencing Batch Reactors
A sequencing batch reactor (SBR) is a suspended growth system in which
wastewater is mixed with existing biological floe in an aeration basin. SBR's are unique
in that a single tank acts as an equalization tank, an aeration tank, and a clarifier.
The capital and O & M costs curves for the SBR systems were obtained from a
vendor service. The average influent BOD5, ammonia as N, and nitrate-nitrite as N
design concentrations used were 4,800 mg/l, 995 mg/l, and 46 mg/l, respectively. The
average effluent BOD5, ammonia as N, and nitrate-nitrite as N concentrations used were
1,600 mg/l, 615 mg/l, and 1.0 mg/l, respectively. These concentrations were obtained
from the sampling data from CWT QID 059. The system costs were calculated for a flow
rate range of 0.001 to 1.0 MGD.
The capital costs for the SBR systems were estimated using the vendor quotes
and represent equipment and installation costs. The equipment items include a tank
system, sludge handling equipment, feed system and controls, pumps, piping, blowers,
and valves. The SBR capital cost equation is:
ln(Y1) = 15.707 + 0.512ln(X) + 0.0022(ln(X))2
7-30
(7-57)
-------
where:
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989 $).
The O & M costs were determined by power, maintenance, labor, and taxes and
insurance. Power was estimated using the vendor values for horsepower used. The
labor requirement for a SBR system was four hours per day. The SBR O & M cost
equation is:
(7-58)
ln(Y2) = 13.139 + 0.562ln(X) + 0.020(ln(X))2
where:
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
To develop land requirements for SBR systems, overall system dimensions were
provided by the vendor. The equation relating the flow of the system to the land
requirement is:
where:
ln(Y3) = -2.971 + 0.097ln(X) + 0.008(ln(X))2
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
7.4 ADVANCED WASTEWATER TREATMENT TECHNOLOGY COSTS
(7-59)
7.4.1 Ultrafiltration
Ultrafiltration (UF) systems are used by industry for the treatment of metal-finishing
wastewater, textile industry effluent, and oily wastes. In the CWT industry, UF is applied
for the treatment of oily wastewater.
7-31
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The components of the UF system include: booster pumps; cartridge prefilters;
control units; high pressure pump and motor assembly; membrane/pressure vessel
assembly; and reject holding tanks. Capital equipment and operational costs were
obtained from manufacturers' quotations. The capital cost equation was developed by
adding installation, engineering, and contingency costs to the vendors' equipment cost.
The system costs were calculated for a flow rate range of 0.000001 to 1.0 MGD. The UF
capital cost equation is:
In(Y1) = 14.672 + 0.8789ln(X) + 0.044(ln(X))2 (7-60)
where:
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989 $).
The O & M costs were based on estimated electricity usage, maintenance, labor,
taxes, and insurance. The electricity usage and costs were provided by the vendors.
The labor requirement for the UF system was approximated at two hours per day.
Concentrate disposal costs were based upon a concentrate generation rate of two percent
of influent flow. The cost of concentrate disposal was quoted as $0.50 per gallon from
CWT QID 409. The UF O & M cost equation is:
where:
ln(Y2) = 15.043 + 1.164In(X) + 0.057(ln(X))2 (7-61)
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
Land requirements were calculated for UF systems using the system dimensions
plus a 20-foot perimeter. The UF land requirement equation is:
ln(Y3) = -1.632 + 0.42ln(X) + 0.035(ln(X))2
(7-62)
7-32
-------
where:
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
7.4.2 Reverse Osmosis
Reverse osmosis (RO) is a high-pressure, fine membrane process for separating
dissolved solids from water. A semi-permeable, microporous membrane and pressure
are used to perform the separation. RO systems are typically used as end-of-pipe
polishing processes, prior to final discharge of recovered wastewater.
The components of the RO system include a booster pump, cartridge prefilters, RO
unit, and a reject holding tank. The capital cost equation was developed by adding
installation, engineering, and contingency costs to the vendors' equipment cost. The
capital and O & M costs were calculated for a flow rate range of 0.000001 to 1.0 -MGD.
The RO capital cost equation is:
where:
ln(Y1) = 15.381 + 0.919ln(X) + 0.04(ln(X))2 (7-63)
X = Flow Rate (MGD) and
Y1 = Capital Cost (1989 $).
The O & M costs were based on estimated electricity usage, maintenance, labor,
taxes, and insurance. The electricity usage and costs were provided by the vendors.
The labor requirement for the RO system was approximated at two hours per day.
Concentrate disposal costs were based on a concentrate generation rate of 28 percent
of influent flow (CWT QID 409). The cost of concentrate disposal was quoted at $0.46
per gallon. The RO O & M cost equation is:
ln(Y2) = 17.599 + 1.303ln(X) + 0.048(ln(X))2
(7-64)
7-33
-------
where:
X = Flow Rate (MGD) and
Y2 = O&M Cost (1989$).
Land requirements were calculated for RO systems using the system dimensions
plus a 20-foot perimeter. The RO land requirement equation is:
ln(Y3) = -2.346 + 0.166!n(X) * 0.012(In(X))2 (7-65)
where:
X = Flow Rate (MGD) and
Y3 = Land Requirement (Acres).
7.5 SLUDGE TREATMENT AND DISPOSAL COSTS
7.5.1 Plate and Frame Pressure Filtration - Sludge Stream
Pressure filtration systems are used for the removal of solids from waste streams.
These systems typically follow chemical precipitation or clarification.
The plate and frame pressure filtration system costs were estimated for a sludge
stream; this consists of the sludge which is collected in the clarification step following
some chemical precipitation processes. The sludge stream consists of 80 percent liquid
and 20 percent (200,000 mg/l) solids. The influent flow rate used for the sludge stream
is 20 percent of the influent flow rate for the liquid wastewater stream. These influent
parameters were taken from CWT QID 105.
The components of the plate and frame pressure filtration system include: filter
plates; filter cloth; hydraulic pumps; pneumatic booster pumps; control panel; connector
pipes; and support platform. Equipment and operational costs were obtained from
manufacturers' recommendations. The capital cost equation was developed by adding
installation, engineering, and contingency costs to the vendors' equipment costs. The
7-34
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system costs were calculated for a flow rate range of 0.000001 to 1.0 MGD. The capital
cost equation for Metals Option 1 sludge filtration is:
where:
ln(Y1) .= 14.827 + 1,087ln(X) + 0.050(ln(X))2 (7-66)
X = Flow Rate (MGD) of Liquid Stream and
Y1 = Capital Cost (1989 $).
The O & M costs were based on estimated electricity usage, maintenance, labor,
taxes and insurance, and filter cake disposal costs. The labor requirement for the plate
and frame pressure filtration system was approximated at thirty minutes per cycle per
filter press.
Filter cake disposal costs were derived from responses to the WTI Questionnaire.
The disposal cost was estimated at $0.74 per gallon of filter cake; this is based on the
cost of contract hauling and disposal in a Subtitle C or Subtitle D landfill. A more detailed
explanation of the filter cake disposal costs development is presented in Subsection 7.5.2.
To determine the total O & M costs for a plate and frame filtration system, the filter cake
disposal costs must be added to the other O & M costs.
The O & M cost equation for Metals Option 1 sludge filtration is:
where:
ln(Y2) = 12.239 + 0.388ln(X) + 0.016(In(X))2 (7-67)
X = Flow Rate (MGD) of Liquid Stream and
Y2 = O&M Cost (1989$).
A pressure filtration system upgrade was calculated to estimate the increase in
O & M costs for facilities that already have a pressure filtration system in-place. These
facilities would need to improve pollutant removals from their current performance levels
to Metals Option 1 levels. To determine the percentage increase from current
performance to Metals Option 1 levels, the ratio of the current performance to Metals
7-35
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Option 1 levels versus the raw data to current performance levels was calculated. This
increase was determined to be three percent, as follows:
O & M Upgrade = Current - Metals Option 1 = 0.03 = 3%
Increase Raw - Current
(7-68)
Therefore, in order for the facilities to perform at Metals Option 1 levels, an O & M
cost upgrade of three percent of the total O & M costs (except for taxes and insurance,
which are a function of the capital cost) would be realized for each facility. The O & M
upgrade cost equation for Metals Option 1 sludge filtration is:
ln(Y2) = 8.499 + 0.331 ln(X) + 0.013(ln(X))2
(7-69)
where:
X = Flow Rate (MGD) of Liquid Stream and
Y2 = O&M Cost (1989$).
Land requirements were calculated for the plate and frame pressure filtration
systems using the system dimensions plus a 20-foot perimeter. The land requirement
equation for Metals Option 1 sludge filtration is:
ln(Y3)= -1.971+0.281 ln(X) +0.018(ln(X))2 (7-70)
where:
X = Flow Rate (MGD) of Liquid Stream and
Y3 = Land Requirements (Acres).
7.5.2 Filter Cake Disposal
The liquid stream and sludge stream pressure filtration systems presented in
Subsections 7.2.3 and 7.5.1, respectively, generate a filter cake residual. There is an
annual O & M cost that is associated with the disposal of this residual. This cost must
7-36
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be added to the pressure filtration equipment O & M costs to arrive at the total O & M
costs for the pressure filtration operation.
To determine the cost of transporting filter cake to an off-site facility for disposal,
an analysis of the WTI Questionnaire response data base was performed. Data from a
subset of questionnaire respondents were pulled for analysis. This subset consisted of
Metals Subcategory facilities that are direct and/or indirect dischargers, and would
therefore be costed for CWT compliance. From these responses, the reported costs for
both the Subtitle C and Subtitle D contract haul/disposal methods of filter cake disposal
were tabulated. This information was edited to eliminate incomplete or combined data
that could not be used.
From this data set, the median cost for both the Subtitle C and Subtitle D disposal
options were determined. Then, the weighted average of these median costs was
determined. The average was weighted to reflect the ratio of hazardous (67 percent) to
nonhazardous (33 percent) waste receipts at these Metals Subcategory facilities. The
final disposal cost is $0.74 per gallon of filter cake.
The filter cake disposal costs were calculated for a flow rate range of 0.000001 to
1.0 MGD. The O & M cost equations for filter cake disposal for the Metals Options 1 and
2 plate and frame filtration full systems and system upgrades are presented as Equations
7-71 and 7-72, respectively.
Z = 0.109169 + 7,6953499.8(X)
Z = 0.101186 + 230,879.8(X)
(7-71)
(7-72)
where:
X = Flow Rate (MGD) of Liquid Stream and
Z = Filter Cake Disposal Cost (1989 $).
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7.6 ADDITIONAL COSTS
7.6.1 Retrofit Costs
Costs were assigned to the CWT Industry on both an option- and facility-specific
basis. The option-specific approach costed a sequence of individual treatment
technologies, corresponding to a particular regulatory option, for a subset of facilities
defined as belonging to that regulatory subcategory. Within the costing of a specific
regulatory option, treatment technology costs were assigned on a facility-specific basis
depending upon the technologies determined to be currently in-place at the facility.
Once it was determined that a treatment technology cost should be assigned to
a particular facility, there were two design scenarios which were considered. The first
was the installation of a new individual treatment technology as a part of a new treatment
train. The full capital costs presented in Subsections 7.2 through 7.5 of this document
apply to this scenario. The second scenario was the installation of a new individual
treatment technology which would have to be integrated into an existing in-place
treatment train. It is in the case of this second scenario that retrofit costs were applied.
These retrofit costs cover such items as piping and structural modifications which would
be required in an existing piece of equipment to accommodate the installation of a new
piece of equipment prior to or within an existing treatment train.
For all facilities which received retrofit costs, a retrofit factor of 20 percent was
applied to the total capital cost of the newly-installed or upgraded treatment technology
unit that would need to integrated into an existing treatment train.
7.6.2 Monitoring Costs
Monitoring costs will be realized by CWT facilities who discharge process
wastewater directly to a receiving stream or indirectly to a POTW. Direct discharge
effluent monitoring requirements are mandated in NPDES permits. Indirect discharge
monitoring requirements are mandated by the operating authority of the POTW.
7-38
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The method developed for the OCPSF Industry was used as the basis for the CWT
monitoring cost estimation. The following generalizations have been used to estimate
compliance monitoring costs:
1) Monitoring costs are based on the number of outfalls through which process
wastewater is discharged. The cost for a single outfall is multiplied by the
number of outfalls to arrive at the total costs for a facility.
2) Flow monitoring equipment costs, are included in, the capital costs for the
specific treatment technologies.
3) Sample collection costs (labor and equipment) and sample shipping costs
are not included.
4) The monitoring costs (based on frequency and analytical methods) are
incremental to the monitoring currently being incurred by the CWT facility.
Respondents to the WTI Questionnaire reported their POTW discharge monitoring
requirements. For direct discharger, NPDES permits were reviewed. This information
shows that most facilities are currently required to monitor for several classical pollutant
parameters (e.g. BOD5, TSS, pH, and cyanide). And, for the parameters that are not
addressed, these analyses are relatively inexpensive. Therefore, costs for classical
pollutant analyses are not included in the cost estimation.
Many facilities are required to monitor for commonly-regulated metals (e.g. lead,
copper, and nickel); however, the CWT list of pollutants includes many more metals than
any facility currently quantifies. Therefore, costs for metals monitoring are included in the
cost estimation.
Very few facilities are required to monitor for organic compounds, so costs are
included for these analyses. EPA method 1624 is used for the quantification of volatile
organic compounds, and Method 1625 is used for the quantification of semivolatile
organic compounds.
The frequency of monitoring currently required in the CWT Industry varies widely
for any specific parameter from daily to semi-annually. An estimated weekly frequency
was used for the cost estimation. This frequency includes a full scan as one of the
analyses each month.
7-39
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The OCPSF methodology assumes that larger dischargers would be required to
monitor for more parameters within a pollutant group. As such, the analytical cost would
increase based on the number of parameters to be quantified. The monitoring costs,
adjusted to 1989 dollars, are presented in Table 7-4.
Table 7-4. Monitoring Costs for the CWT Industry Cost Exercise
Flow Rate Range (MGD)
<0.5
0.5 - 4.99
5 - 9.99
>10
Annual Monitoring Costs
(1989$)
per Outfall
40,680
61 ,725
68,100
134,525
7.6.3 RCRA Permit Modification Costs
Respondents to the WTI Questionnaire whose RCRA Part B permits were modified
were asked to report the following information pertaining to the cost of obtaining the
modification:
Legal fees;
• Administrative costs;
Public relations costs;
• Other costs; and
• Total costs.
The purpose of the permit modification was also asked. Anticipated changes to
a facility's RCRA permit as a result of the implementation of CWT regulations include the
upgrade of existing equipment and/or the installation of new treatment technologies to
achieve effluent limitations. These changes correlate with the purposes identified by the
WTI Questionnaire respondents as "new tanks", "new units", "new technologies", and
"other - modification of existing equipment". The applicable costs are summarized in
Table 7-5.
7-40
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Table 7-5. RCRA Permit Modification Costs Reported in WTI Questionnaire
Modification
New Units
New Technology
Modify Existing
Equipment
Average
QID
081
255
081
090
402
-
Year
1990
. 1990.
1990
1990
1991
-
Total Cost
(reported $)
26,000
7,000
82,000
6,300,000*
14,080
-
Total Cost
(1989$)
25,357
6,827
79,793
6,144,231*
13,440
31 ,400
This cost includes equipment and installation costs; no cost breakdown is
given. Therefore, this cost was not used in calculating the average cost.
7.6.4 Land Costs
An important factor in the calculation of treatment technology costs is the value of
the land needed for the installation of the technology. Due to continuing development,
the availability and therefore the cost of land can prove to be a significant part of the
capital cost. To determine the amount of land required for costing purposes, the land
requirements for each treatment technology were calculated for the range of system
sizes. These land requirements were fitted to a curve so that a land requirement, in
acres, could be calculated for every treatment system costed. The individual land
requirements were then multiplied by the corresponding land cost estimates to obtain
facility-specific cost estimates. Since land costs may vary widely across the country, a
nationwide average figure would not be representative. Therefore, the average land costs
for suburban sites in each state were obtained from the 1990 Guide to Industrial and Real
Estate Office Markets survey.
According to the survey, the unimproved sites are the most desirable of the
existing inventory and are zoned for industrial use; therefore, unimproved land costs
7-41
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were used in this analysis. The survey categorizes the states into regions by
geographical location: northeast, north central, south, and west. For states that have no
land prices available in the survey, the regional average figures were used. In calculating
the regional average costs for the western region, Hawaii wasi not included. This is
because Hawaii's land cost is disproportionately high and its inclusion would have skewed
the regional average.
The survey report data are also broken down by site size ranges; these are zero
to 10 acres, 10 to 100 acres, and greater than 100 acres. The respondents to the WTI
Questionnaire reported total facility areas ranging from less than one acre to 2,700 acres
and undeveloped facility areas from zero to 1,775 acres. Since the CWT facilities fall into
all three size ranges covered by the report data, the three size-specific land costs for
each state were averaged to arrive at the final costs for the industry. As Table 7-6
indicates, that the least expensive state is Kansas with a land cost of $7,042 per acre.
The most expensive state is Hawaii with a land cost of $1,089,000 per acre.
7-42
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Table 7-6. State Land Costs for the CWT Industry Cost Exercise
State
Alabama
Alaska*
Arizona
Arkansas
California
Colorado
Connecticut
Delaware
Florida
Georgia
Hawaii
Idaho*
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana*
Land Cost per
Acre (1989$)
22,773
81,105
46,101
15,899
300,927
43,560
54,232
54,450
63,273
72,600
1,089,000
81,105
36,300
21 ,078
8,954
7,042
29,040
56,628
19,602
112,530
59,895
13,649
21 ,054
13,068
39,930
81,105
State
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota*
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island*
South Carolina
South Dakota*
Tennessee
Texas
Utah*
Vermont*
Virginia
Washington
West Virginia*
Wisconsin
Wyoming*
Washington DC
Land Cost per
Acre (1989 $)
24,684
36,300
52,998
89,443
26,929
110,013
33,880
20,488
14,578
24,321
50,820
32,307
59,822
21 ,296
20,488
20,873
47,674
81,105
59,822
39,930
63,670
47,345
17,424
81,105
174,240
No data available for state, used regional average.
7-43
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7.7 REFERENCES
Standard Methods for Examination of Water and Wastewater. 15th Edition, Washington,
DC.
Henricks, David, Inspectors Guide for Evaluation of Municipal Wastewater Treatment
Plants. Culp/Wesner/Culp, El Dorado Hills, CA, 1979.
Technical Practice Committee, Operation of Wastewater Treatment Plants. MOP/11,
Washington, DC, 1976.
Clark, Viesman, and Hasner, Water Supply and Pollution Control. Harper and Row
Publishers, New York, NY, 1977.
1991 Waste Treatment Industry Questionnaire Respondents Data Base. U. S.
Environmental Protection Agency, Washington, DC.
Osmonics, Historical Perspective of Ultratiltration and Reverse Osmosis Membrane
Development. Minnetonka, MN, 1984.
Organic Chemicals and Plastics and Synthetic Fibers (OCPSF) Cost Document. SAIC,
1987.
Effluent Guidelines Division, Development Document For Effluent Limitations Guidelines
and Standards for the Organic Chemicals. Plastics and Synthetic Fibers (OCPSF).
Volume II, Point Source Category, EPA 440/1-87/009, Washington, DC, October 1987.
Engineering News Record (ENR). McGraw-Hill, New York, NY, March 30, 1992.
Comparative Statistics of Industrial and Office Real Estate Markets. Society of Industrial
and Office Realtors of the National Association of Realtors, Washington, DC, 1990.
Peters, M., and Timmerhaus, K., Plant Design and Economics for Chemical Engineers,
McGraw-Hill, New York, NY, 1991.
Chemical Marketing Reporter. Schnell Publishing Company, Inc., New York, NY, May 10,
1993.
Palmer, S.K., Breton, M.A., Nunno, T.J., Sullivan, D.M., and Supprenaut, N.F.,
Metal/Cyanide Containing Wastes Treatment Technologies. Alliance Technical
Corporation, Bedford, MA, 1988.
Freeman, H.M., Standard Handbook of Hazardous Waste Treatment and Disposal. U.S.
Environmental Protection Agency, McGraw-Hill, New York, NY, 1989.
7-44
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SECTION 8
DEVELOPMENT OF LIMITATIONS AND STANDARDS
This section describes various waste treatment technologies and their costs,
pollutants proposed for regulation, and pollutant reductions associated with the different
treatment technologies obtained for the proposed effluent limitations guidelines and
standards for the Centralized Waste Treatment Industry. The limitations and standards
discussed in this section are Best Practicable Control Technology Currently Available
(BPT), Best Conventional Pollutant Control Technology (BCT), Best Available Technology
Economically Achievable (BAT), New Source Performance Standards (NSPS),
Pretreatment Standards for Existing Sources (PSES), and Pretreatment Standards for
New Sources (PSNS).
8.1 ESTABLISHMENT OF BPT
Generally, EPA bases BPT upon the average of the best current performance (in
terms of treated effluent discharged) by facilities of various sizes, ages, and unit
processes within an industry or subcategory. The factors considered in establishing the
best practicable control technology currently available (BPT) include: (1) the total cost of
applying the technology relative to the effluent reductions that result, (2) the age of
process equipment and facilities involved, (3) the processes employed and required
process changes, (4) the engineering aspects of the control technology, (5) non-water
quality environmental impacts such as energy requirements, air pollution and solid waste
generation, and (6) such other factors as the Administrator deems appropriate (section
304(b)(2)(B) of the Act). As noted, BPT technology represents the average of the best
existing performances of facilities within the industry. When existing performance is
uniformly inadequate, EPA may require a higher level of control than is currently in place
in an industrial category if EPA determines that the technology can be practically applied.
BPT may be transferred from a different subcategory or category. However, BPT
8-1
-------
normally focuses on end-of-process treatment rather than process changes or internal
controls, except when these technologies are common industry practice.
The cost/effluent reduction inquiry for BPT is a limited balancing one, committed
to EPA's discretion, that does not require the Agency to quantify effluent reduction
benefits in monetary terms. See, e.g., American Iron and Steel Institute v. EPA, 526 F.
2d 1027 (3rd Cir., 1975). In balancing costs against the effluent reduction benefits, EPA
considers the volume and nature of discharges expected after application of BPT, the
general environmental effects of pollutants, and the cost and economic impacts of the
required level of pollution control. In developing guidelines, the Act does not require or
permit consideration of water quality problems attributable to particular point sources, or
water quality improvements in particular bodies of water. Therefore, EPA has not
considered these factors in developing the proposed limitations. See Weyerhaeuser
Company v. Costle, 590 F. 2d 1011 (D.C. Cir. 1978).
EPA concluded that the wastewater treatment performance of the facilities it
surveyed was, with very limited exceptions, uniformly poor. Under these circumstances,
for each subcategory, EPA has preliminarily concluded that only one treatment system
meets the statutory test for best practicable, currently available technology. EPA has
determined that the performance of facilities which mix different types of highly
concentrated CWT wastes with non-CWT waste streams or with stormwater are not
providing BPT treatment. The mass of pollutants being discharged is unacceptably high.
Thus, comparison of EPA sampling data and CWT industry-supplied monitoring
information establishes that, in the case of metal-bearing waste streams, virtually all the
facilities are discharging large total quantities of heavy metals. As measured by total
suspended solids (TSS) levels following treatment, TSS concentrations are substantially
in excess of levels observed at facilities in other industry categories employing the same
treatment technology — 10 to 20 times greater than observed for other point source
categories.
In the case of oil discharges, most facilities are achieving low removal of oils and
grease relative to the performance required for other point source categories. Further,
8-2
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facilities treating organic wastes, while successfully-removing organic pollutants through
biological treatment, fail to remove metals associated with these organic wastes.
The poor pollutant removal performance observed generally for discharging CWT
facilities is not unexpected. As pointed out previously, these facilities are treating highly
concentrated wastes that, in many cases, are process residuals and sludges from other
point source categories. EPA's review of permit limitations for the direct dischargers show
that, in most cases, the dischargers are subject to "best professional judgment"
concentration limitations which were developed from guidelines for facilities treating and
discharging much more dilute waste streams. EPA has concluded that treatment
performance in the industry is widely inadequate and that the mass of pollutants being
discharged is unacceptably high, given the demonstrated removal capability of treatment
operation that the Agency reviewed.
8.1.1 Rationale for Metals Subcategory BPT Limitations
In determining BPT, EPA evaluated metals precipitation as the principal treatment
practice within the subcategory. Forty-seven of the 56 facilities in the Metals Subcategory
use metals precipitation as a means for waste treatment. The precipitation techniques
used by facilities varied in the treatment chemicals used and operation of the precipitation
system, e.g., batch, continuous, or selective metals precipitation. In the process of
selecting facilities for sampling, there was difficulty is gathering data from direct
dischargers for establishing limitations and standards. Because BPT applies to direct
dischargers, the data used to establish limitations and standards developed are normally
collected from such facilities. Most facilities in the Metals Subcategory, however, are
indirect dischargers and therefore do not monitor or optimize the performance of their
treatment system for treatment of conventional pollutants. (Indirect dischargers generally
are not required to control their discharges of conventional pollutants because the
receiving POTWs are designed to achieve the conventional removals.) Therefore, when
reviewing the analytical data collected, EPA concluded that the treatment performance
8-3
-------
by indirect dischargers could not be characterized as the average of the best
performance, because systems were obviously not operated so as to remove
conventional pollutants. After evaluating various metals precipitation processes, EPA
considered three regulatory options to reduce the discharge of pollutants by Centralized
Waste Treatment facilities.
The three technology options considered for the Metals Subcategory BPT are:
• Option 1 - Chemical precipitation, Solid-Liquid separation, and Sludge
dewatering. Under Option 1, BPT limitations would be based upon
chemical precipitation with a lime/caustic solution followed by some form of
separation and sludge dewatering to control the discharge of pollutants in
wastewater. The data reviewed for this option showed that
settling/clarification followed by pressure filtration of sludge yields removals
equivalent to pressure filtration. In general, while the proposed BPT
limitations would require the improvement of current treatment technologies
in-place through increased quantities of treatment chemicals and additional
monitoring of batch processes, this precipitation process is employed by
many facilities. For metals streams which contain concentrated cyanide
complexes, the proposed BPT limitations are based on alkaline chlorination
at specific operating conditions prior to metals treatment. As previously
noted, without treatment of cyanide waste streams prior to metals treatment,
metals removals are significantly reduced.
Option 2 - Selective Metals Precipitation, Pressure Filtration, Secondary
Precipitation, and Solid-Liquid Separation. The second option evaluated for
BPT for Centralized Waste Treatment facilities is based on the use of
numerous treatment tanks and personnel to handle incoming waste
streams, and the use of greater quantities of caustic in the treatment
chemical mixture. (Caustic sludge is easier to recycle.) Option 2 is based
on additional tanks and personnel to segregate incoming waste streams
and to monitor the batch treatment processes to maximize the precipitation
8-4
-------
of specific metals in order to generate a metal-rich filter cake. The metal-
rich filter cake could possibly be sold to metal smelters to incorporate into
metal products. Like Option 1, for metals streams which contain
concentrated cyanide complexes, under Option 2, BPT limitations are
based on alkaline chlorination at specific operating conditions prior to
metals treatment.
Option 3 - Selective Metals Precipitation, Pressure Filtration, Secondary
Precipitation, Solid-Liquid Separation, and Tertiary Precipitation. The
technology basis for Option 3 is the same as Option 2 except an additional
precipitation step at the end of treatment is added. For metals streams
which contain concentrated cyanide complexes, like Option 1 and 2, for
Option 3, alkaline chlorination at specific operating conditions would be the
basis for BPT limitations.
The Agency is proposing to adopt BPT effluent limitations based on Option 3 for
the Metals Subcategory. These limitations were developed based on an engineering
evaluation of the average of the best demonstrated methods to control the discharges of
the regulated pollutants in this Subcategory. The proposed BPT limitations for the Metals
Subcategory are presented in Table 8-1. Draft long-term averages for Options 1 and 2
are presented in the Statistical Support Document for Proposed Effluent Limitations
Guidelines and Standards for the Centralized Waste Treatment Industry as well as the
methodology for calculating the variability factors used to calculate limitations.
EPA's tentative decision to base BPT limitations on Option 3 treatment reflects
primarily an evaluation of three factors: the degree of effluent reduction attainable, the
total cost of the proposed treatment technologies in relation to the effluent reductions
achieved, and potential non-water quality benefits. In assessing BPT, EPA considered
the age, size, process, other engineering factors, and non-water quality impacts pertinent
to the facilities treating wastes in this Subcategory. No basis could be found for
identifying different BPT limitations based on age, size, process or other engineering
factors. Neither the age nor the size of the CWT facility will directly affect either the
8-5
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Table 8-1. BPT Effluent Limitations for the Metals Subcategory
Pollutant or Pollutant
Parameter
Maximum for
Any One Day
Monthly Average
Conventional Pollutants
Oil & Grease
TSS
45
55
11
18
Priority and Non-Conventional Pollutants
Aluminum
Antimony
Arsenic
Barium
Cadmium
Chromium
Cobalt
Copper
Hexavalent Chromium
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Silver
Tin
Titanium
Total Cyanide
Zinc
0.72
0.14
0.076
0.14
0.73
0.77
0.73
1.0
0.14
2.4
0.37
9.9
0.18
0.013
5.4
0.028
0.20
0.021
4.4
1.2
0.16
0.031
0.017
0.032
0.16
0.17
0.16
0.23
0.077
0.54
0.082
2.2
0.039
0.0030
1.2
0.0063
0.044
0.0047
1.2
0.27
In-Facility BPT Limitations for Cyanide Pretreatment
Total Cyanide
350
130
8-6
-------
character or treatabiiity of the CWT wastes or the cost of treatment. Further, the
treatment process and engineering aspects of the technologies considered have a
relatively insignificant effect because in most cases they represent fine tuning or add-ons
to treatment technology already in use. These factors consequently did not weigh
heavily in the development of these guidelines. For a service industry whose service is
wastewater treatment, the most pertinent factors for establishing the limitations are costs
of treatment, the level of effluent reductions obtainable, and non-water quality effects.
Generally, for purposes of defining BPT effluent limitations, EPA looks at the
performance of the best operated treatment system and calculates limitations from some
level of average performance of these "best" facilities. For example, in proposing BPT
limitations for the pulp, paper and paper board category, EPA compared the average
removal performance of the best 90 percent of paper mills and the performance level
representing the average for the best 50 percent of the mills (58 FR 66078, 66105
(December 17, 1993)). For this industry, as previously explained, EPA concluded that
treatment performance is, in virtually all cases, poor. Without separation of metal-bearing
streams for selective precipitation, metal removal levels are uniformly inadequate across
the industry. Consequently, BPT performance levels are based on data from the one
well-operated system using selective metals precipitation that was sampled by EPA.
The demonstrated effluent reductions attainable through the Option 3 control
technology represent the BPT performance attainable through the application of
demonstrated treatment measures currently in operation in this industry. The Agency is
proposing to adopt BPT limitations based on the removal performance of the Option 3
treatment system for the following reasons. First, these removals are demonstrated by
a facility in this subcategory and can readily be applied to all facilities in the subcategory.
The adoption of this level of control would represent a significant reduction in pollutants
discharged into the environment
Second, the Agency assessed the total cost of water pollution controls likely to be
incurred for Option 3 in relation to the effluent reduction benefits and determined these
costs were reasonably achievable. While the absolute costs of selective metals
8-7
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precipitation (Options 2 and 3) are significantly higher than Option 1, EPA concluded the
costs were still reasonable. EPA's cost assessment shows that selective metals
precipitation would not adversely affect profitability within this subcategory. EPA
calculated that four facilities would experience decreased profitability while seven would
show an increase in profitability. The expenses associated with selective metals
precipitation would not cause any of the 12 direct dischargers currently to go from a
profitable to unprofitable status. Addition of a further precipitation step (Option 3) did not
change these results.
Third, adoption of these BPT limits could promote the non-water quality objectives
of the CWA. Use of the Option 3 treatment regime — which generates a metal-rich filter
cake that may be recovered and smelted — could reduce the quantity of waste which are
being disposed of in landfills.
The Agency proposes to reject Option 1 because, as discussed above, EPA
concluded that mixing disparate metal-bearing waste streams is not the best practicable
treatment technology currently in operation for this subcategory of the industry.
Consequently, effluent levels associated with this treatment option would not represent
BPT performance levels. Option 2 was rejected, although similar to Option 3, because
the greater removals obtained through addition of tertiary precipitation at Option 3 were
obtained at a relatively insignificant increase in costs over Option 2.
In the process of selecting facilities for sampling, there was difficulty is gathering
data from direct dischargers for establishing limitations and standards. Since BPT applies
to direct dischargers, the limitations and standards developed are normally collected from
such facilities. Most facilities in the Metals Subcategory are indirect dischargers and do
not monitor or optimize the performance of their treatment system for treatment of
conventional pollutants. Therefore, when reviewing the analytical data collected, EPA
concluded that performance by indirect dischargers is not representative of the average
of the best performance because these systems were not operated properly for the
removal of conventional pollutants, thus, incidentally reducing metals removals.
8-8
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8.1.2 Rationale for Oils Subcategory BPT Limitations
In determining BPT for the Oily Subcategory, EPA evaluated a variety of different
treatment methods used within the subcategory. Treatment varies depending on the type
of oils accepted for treatment and other on-site operations. A majority of facilities, 29 out
of 34, use chemical emulsion-breaking as a means to separate stable oil-water emulsions.
The remaining facilities treat less stable oily wastes by gravity separation, dissolved air
flotation (DAF), or in flocculation/clarification treatment system designed for a wide variety
of waste streams.
Treatment of the wastewater resulting from emulsion-breaking is also
accomplished by a variety of methods. Most of the facilities which use emulsion-breaking
treat the resulting wastewater in a flocculation/clarification treatment system designed to
treat a variety of waste streams. Only one facility was identified as treating the
wastewater resulting from emulsion-breaking in a system specifically designed for the
pollutants in an oily waste stream. After evaluating various treatment operations, EPA
identified four regulatory options (identified from operations at the one facility which was
specifically designed for the treatment of oily wastes) for consideration to reduce the
discharge of pollutants by Centralized Waste Treatment facilities.
The four technology options considered for the Oils Subcategory BPT are:
Option 1 - Emulsion-Breaking. Under Option 1, BPT limitations would be
based on present performance of emulsion-breaking processes using acid
and heat to separate oil-water emulsions. At present, most facilities have
this technology in place unless unstable oil-water mixtures are accepted for
treatment. Stable oil-water emulsions require some emulsion-breaking
treatment because gravity separation or flotation alone is inadequate to
breakdown the oil-water waste stream.
Option 2 - Ultrafiltration. Under Option 2, BPT limitations are based on the
use of ultrafiltration for treatment of less concentrated, unstable oily waste
8-9
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receipts or for the additional treatment of wastewater from the emulsion-
breaking process.
Option 3 - Ultrafiltration, Carbon Adsorption, and Reverse Osmosis. The
Option 3 BPT effluent limitations are based on the use of Carbon
Adsorption and Reverse Osmosis in addition to the Option 2 technology.
The reverse osmosis unit removes metals compounds found at significant
levels for this subcategory. Inclusion of a carbon adsorption unit is
necessary in order to protect the reverse osmosis unit by filtering out any
large particles which may damage the reverse osmosis unit or decrease
membrane performance.
• Option 4 - Ultrafiltration, Carbon Adsorption, Reverse Osmosis, and Carbon
Adsorption. Option 4 is similar to Option 3 except for the additional carbon
adsorption unit for final effluent polishing.
The Agency is proposing BPT effluent limitations for the Oily Waste Subcategory
based on Option 3 as well as Option 2 treatment systems. The proposed BPT limitations
for the Oils Subcategory are presented in Table 8-2. Draft long-term averages for
Options 1 and 4 are presented in the Statistical Support Document for Proposed Effluent
Limitations Guidelines and Standards for the Centralized Waste Treatment Industry as
well as the methodology for calculating the variability factors used to calculate limitations.
The EPA has preliminarily concluded that both options represent best practicable control
technologies. The technologies are in-use in the industry and the data collected by the
Agency show that the limitations are being achieved. In assessing BPT, EPA considered
age, size, process, other engineering factors, and non-water quality impacts pertinent to
the facilities treating wastes in this subcategory. No basis could be found for identifying
different BPT limitations based on age, size, process or other engineering factors for the
reasons previously discussed. For a service industry whose service is wastewater
treatment, the pertinent factors here for establishing the limitations are costs of treatment,
the level of effluent reductions obtainable, and non-water quality effects.
8-10
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Table 8-2. BPT Effluent Limitations for the Oils Subcategory (mg/l)
Pollutant or Pollutant
Parameter
Option 2
Maximum
for
any One
Day
Monthly
Average
Option 3
Maximum
for
any One
Day
Monthly
Average
Conventional Pollutants
Oil & Grease
TSS
30,000
24
5,900
8.2
240
4.0
64
1.4
Priority and Non-Conventional Pollutants
1,1,1 -Trichloroethane
2-Propanone
4-Chloro-3-Methyl Phenol
Aluminum
Barium
Benzene
Butanone
Cadmium
Chromium
Copper
Ethyl Benzene
Iron
Lead
Manganese
Methylene Chloride
m-Xylene
Nickel
1.6
41
5.2
2.3
0.10
9.0
3.7
1.5
2.2
2.0
1.1
75
5.0
5.4
3.9
1.6
120
1.0
22
4.4
0.57
0.026
6.8
2.0
0.37
0.54
0.50
0.86
19
1.2
1.3
2.0
1.2
29
0.18
130
0.96
0.085
0.0027
1.8
13
0.0046
0.010
0.016
0.085
0.40
0.076
0.043
2.2
0.074
2.2
0.12
44
0.54
0.038
0.0012
1.4
4.3
0.0020
0.0045
0.0073
0.066
0.18
0.034
0.019
0.91
0.058
0.99
8-11
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Table 8-2. BPT Effluent Limitations for the Oils Subcategory (mg/l) (continued)
Pollutant or Pollutant
Parameter
Option 2
Maximum
for
any One
Day
Monthly
Average
Option 3
Maximum
for
any One
Day
Monthly
Average
Priority and Non-Conventional Pollutants (continued)
n-Decane
n-Docosane
n-Eicosane
n-Hexacosane
n-Hexadecane
n-Octadecane
n-Tetradecane
o&p-Xylene
Tetrachloroethene
Tin
Toluene
Tripropyleneglycol Methyl
Ether
Zinc
0.18
0.18
0.18
0.18
0.18
0.18
0.18
0.86
0.23
0.82
17
280
22
0.096
0.096
0.096
0.096
0.096
0.096
0.096
0.65
0.14
0.20
13
150
5.6
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0.045
0.032
0.12
1.8
160
0.54
0.067
0.067
0.067
0.067
0.067
0.067
0.067
0.035
0.016
0.056
1.4
57
0.24
8-12
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Among the options considered by the Agency, both Options 2 and 3 would provide
for significant reductions in regulated pollutants discharged into the environment over
current practice in the industry represented by Option 1. EPA is nonetheless, concerned
about the cost of Option 3 because it is substantially more expensive than Option 2.
However, EPA's economic assessment indicates, that under either Option 2 or 3, although
one of four direct dischargers will experience some reduction in profitability, the other
three facilities will see an increase. Even under Option 3, no facility in the subcategory
would move from a profitable to unprofitable status. In these circumstances, EPA
concluded that the costs of Option 3 may not be wholly disproportionate to the effluent
reductions benefits achieved, particularly when other factors are taken into account.
As noted, the Agency is proposing Option 2 because it is a currently available and
cost-effective treatment option. However, the BPT pollutant removal performance
required for a number of specific pollutants (particularly oil and grease and metals) is less
stringent than current BPT effluent limitations guidelines promulgated for other industries.
EPA is concerned about the potential for encouraging off-site shipment of oily waste now
being treated on-site if the limitations for this subcategory are significantly different from
those other BPT effluent limitations currently in effect.
The Agency proposes to reject Option 1, because the technology does not provide
for adequate control of the regulated pollutants. The Agency also proposes to reject
Option 4 because less pollutant reductions occur in comparison to Option 3.
Theoretically, Option 4 should provide for the maximum reduction of pollutants discharged
due to the addition of carbon adsorption units, but specific pollutant concentrations
increase across the carbon adsorption unit according to the analytical data collected.
Even though, as previously explained, BPT limitations are generally defined by the
average effluent reduction performance of the best existing treatment systems, here, as
was the case with the BPT metal-bearing wastes limitations, the options being proposed
as the basis for BPT effluent limitations are based upon the treatment performance at a
single facility. EPA concluded that existing performance at the other facilities is uniformly
inadequate because many facilities that will be subject to the limitations for the Oily
8-13
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Waste Subcategory now commingle the oily wastewater with other wastes prior to
treatment. The Agency has determined that the practice of mixing waste streams before
treatment results in inadequate removal of the regulated pollutants of concern for the Oils
Subcategory. Oily wastewater contains significant levels of organic and metals
compounds. If the oily wastewater is mixed with other CWT wastewater, these organic
and metals compounds are often found at non-detectable levels pjior to treatment
because the oily wastewater is effectively diluted by the other wastewater to the point that
the compounds are no longer detectible. The treatment system on which the Options 2
through 4 effluent limitations are based was designed specifically for the treatment of
segregated oily wastewater.
8.1.3 Rationale for Organics Subcategory BPT Limitations
Determining BPT for the Organics Subcategory was a difficult process. Most
facilities in the Organics Subcategory have other non-CWT operations, such as organics
manufacturing. The portion of CWT wastes and wastewater treated at the facility was
minor in comparison to the overall facility flow. The CWT flows are a majority of the
overall facility flow for only nine out of the 16 facilities in the Subcategory. For organic
waste streams, biological treatment is typically the predominant technology used. Due
to the types of pollutants identified in the Organics Subcategory, most facilities in this
Subcategory use air stripping as a means for controlling volatile organics and multimedia
or carbon adsorption for final effluent polishing. As discussed in Section 3, one facility
was identified which developed a treatment system for recovering the organic constituents
in the waste stream, but data from this facility could not be used for limitation
development because it was not being operated so as to optimize removals at the time
of the EPA sampling episode. Therefore, the EPA used the treatment technologies
located at one facility to develop the two options for this subcategory.
The two technology options considered for the Organics Subcategory BPT are:
8-14
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Option 1 - Equalization, Air-Stripping, Biological Treatment, and Multi-media
Filtration. BPT Option 1 effluent guidelines are based on the following
treatment system: equalization, two air-strippers in series equipped with a
carbon adsorption unit for control of air emissions, biological treatment in
the form of a sequential batch reactor (which is operated on a batch basis),
and finally multi-media filtration units for control of solids.
Option 2 - Equalization, Air-Stripping, Biological Treatment, Multi-media
Filtration, and Carbon Adsorption. Option 2 is the same as Option 1 except
for the addition of carbon adsorption units.
The Agency is proposing to adopt BPT effluent limitations based on the Option 1
technology for the Organics Subcategory. The proposed BPT limitations for the Organics
Subcategory are presented in Table 8-3. Draft long-term averages for Options 2 are
presented in the Statistical Support Document for Proposed Effluent Limitations
Guidelines and Standards for the Centralized Waste Treatment Industry as well as the
methodology for calculating the variability factors used to calculate limitations. The
demonstrated effluent reductions attainable through Option 1 control technology
represent the best practicable performance attainable through the application of currently
available treatment measures. EPA's decision to propose effluent limitations defined by
the removal performance of the Option 1 treatment systems is based primarily on
consideration of several factors: the effluent reductions attainable, the economic
achievability of the option and non-water quality environmental benefits. Once again, the
age and size of the facilities, processes and other engineering factors were not
considered pertinent to establishment of BPT limitations for this Subcategory.
8-15
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Table 8-3. BPT Effluent Limitations for the Organics Subcategory (mg/I)
Pollutant or Pollutant
Parameter
Maximum for Any
One Day
Monthly Average
Conventional Pollutants
BOD,
Oil & Grease
TSS
163
13
216
53
4.9
61
Priority and Non-Conventional Pollutants
1,1,1 ,2-Tetrachloroethane
1,1,1 -Trichloroethane
1 ,1 ,2-Trichloroethane
1 ,1-Dichloroethene
1 ,2,3-Trichloropropane
1 ,2-Dibromoethane
1,2-Dichloroethane
2,3-Dichloroaniline
Butanone
2-Propanone
4-Methyl-2-Pentanone
Acetophenone
Aluminum
Antimony
Barium
Benzene
Benzoic Acid
Carbon Disulfide
Chloroform
0.013
0.021
0.21
0.037
0.016
0.014
0.031
0.17
1.1
1.6
0.093
0.048
1.3
0.42
3.8
0.014
0.49
0.16
0.56
0.011
0.018
0.17
0.027
0.014
0.011
0.025
0.14
0.84
1.3
0.074
0.022
0.75
0.24
2.2
0.011
0.24
0.11
0.48
8-16
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Table 8-3. BPT Effluent Limitations for the Organies Subcategory (mg/l) (continued)
Pollutant or Pollutant
Parameter
Maximum for Any
One Day
Monthly Average
Priority and Non-Conventional Pollutants
Diethyl Ether
Hexanoic Acid
Lead
Methylene Chloride
Molybdenum
m-Xylene
o-Cresol
Phenol
Pyridine
D-Cresol
Tetrachloroethene
Tetrachloromethane
Toluene
trans-1 ,2-dichloroethene
Trichloroethene
Vinyl Chloride
Zinc
0.070
0.51
0.16
1.1
0.98
0.014
0.051
0.79
0.71
0.098
0.73
0.013
0.014
0.15
1.2
0.071
0.43
0.056
0.25
0.095
0.97
0.57
0.011
0.025
0.38
0.24
0.040
0.53
0.011
0.011
0.11
0.86
0.052
0.25
8-17
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The Agency is proposing to adopt BPT limitations based on the removal
performance of the Option 1 treatment system for the following reasons. First, the cost
of achieving the pollutant discharge levels associated with the Option 1 treatment system
is reasonable. The annualized costs for treatment are low. Further, EPA estimates that
meeting the Option 1 BPT limitations, while adversely affecting the profitability of two of
six direct dischargers would increase the profitability of the other four. No facility moves
from profitable to unprofitable status. Second, the costs are not only low generally but
low relative to the removals achieved. Third, significant non-water quality benefits may
be expected from the installation of air stripping units equipped with carbon adsorption
units which prevent volatilization of organic compounds.
According to the data collected, the Option 1 treatment system provides a greater
effluent pollutant reduction level than the more expensive Option 2. Theoretically, Option
2 should provide for the maximum reduction of pollutants discharged due to the addition
of carbon adsorption units, but specific pollutants of concern increased across the carbon
adsorption unit according to the analytical data collected. Due to the poor performance
of carbon adsorption in EPA's database for this industry, Option 2 is rejected. The poor
performance may be a result of pH fluctuations in the carbon adsorption unit resulting in
the solubilization of metals. Similar trends have been found for all of the data collected
on carbon adsorption units in this industry.
The Agency used biological treatment performance data from the OCPSF
regulation to establish direct discharge limitations for BOD5 and TSS, because the facility
from which Option 1 and 2 limitations were derived is an indirect discharger and the
treatment system is not operated to optimize removal of conventional pollutants. EPA has
concluded that the transfer of this data is appropriate given the absence of adequate
treatment technology for these pollutants at the only otherwise well-operated BPT CWT
facility. Given the treatment of similar wastes at both OCPSF and centralized waste
treatment facilities, use of the data is warranted. Moreover, EPA has every reason to
believe that the same treatment systems will perform similarly when treating the wastes
in this subcategory.
8-18
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Once again, the selected BPT option is based on the performance of a single
facility. Many facilities that are treating wastes that will be subject to effluent limitations
for the Organic-Bearing Waste Subcategory also operate other industrial processes that
generate much larger amounts of wastewater than the quantity of off-site generated
organic waste receipts. The off-site generated organic waste receipts are directly mixed
with the wastewater from the other industrial processes for treatment. Therefore,
identifying facilities to sample for limitations development was difficult because the waste
receipts and treatment unit effectiveness could not be properly characterized for off-site
generated waste. The treatment system for which Options 1 and 2 is based upon was
one of the few facilities identified which treated organic waste receipts separately from
other on-site industrial wastewater.
8.2 BCT
EPA is proposing BCT equivalent to the BPT guidelines for the conventional
pollutants covered under BPT. In developing BCT limits, EPA considered whether there
are technologies that achieve greater removals of conventional pollutants than proposed
for BPT, and whether those technologies are cost-reasonable according to the BCT Cost
Test. In all three subcategories, EPA identified no technologies that can achieve greater
removals of conventional pollutants than proposed for BPT that are also cost-reasonable
under the BCT Cost Test, and accordingly EPA proposes BCT effluent limitations equal
to the proposed BPT effluent limitations guidelines and standards.
8.3 BAT
EPA is proposing BAT effluent limitations for all subcategories of the Centralized
Waste Treatment Industry based upon the same technologies evaluated and proposed
for BPT for each subcategory. The proposed BAT effluent limitations would control
identified priority and non-conventional pollutants discharged from facilities.
8-19
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EPA has not identified any more stringent treatment technology option which it
considered to represent BPT level of control applicable to facilities in this industry for the
metals, oils, and organics subcategories. EPA identified an add-on treatment technology
— carbon adsorption — that should have further increased removals of pollutants of
concern. However, as explained above, EPA's data show increases rather than
decreases in concentrations of specific pollutants of concern.
8.4 NSPS
As previously noted, under section 306 of the Act, new industrial direct dischargers
must comply with standards which reflect the greatest degree of effluent reduction
achievable through application of the best available demonstrated control technologies.
Congress envisioned that new treatment systems could meet tighter controls than existing
sources because of the opportunity to incorporate the most efficient processes and
treatment systems into plant design. Therefore, Congress directed EPA to consider the
best demonstrated process changes, in-plant controls, operating methods and end-of-
pipe treatment technologies that reduce pollution to the maximum extent feasible.
EPA is proposing NSPS that would control the same conventional, priority, and
non-conventional pollutants proposed for control by the BPT effluent limitations. The
technologies used to control pollutants at existing facilities are fully applicable to new
facilities. Furthermore, EPA has not identified any technologies or combinations of
technologies that are demonstrated for new sources that are different from those used to
establish BPT/BCT/BAT for existing sources. Therefore, EPA is establishing NSPS
subcategories similar to the subcategories for existing facilities and proposing NSPS
limitations that are identical to those proposed for BPT/BCT/BAT.
8-20
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8.5 PSES
Indirect dischargers in the Centralized Waste Treatment Industry, like the direct
dischargers, accept for treatment wastes containing many priority and non-conventional
pollutants. As in the case of direct dischargers, indirect dischargers may be expected to
discharge many of these pollutants to POTWs at significant mass and concentration
levels. EPA estimates that indirect dischargers annually discharge approximately 85.3
million pounds of pollutants.
Section 307(b) requires EPA to promulgate pretreatment standards to prevent
pass-through of pollutants from POTWs to waters of the U.S. or to prevent pollutants from
interfering with the operation of POTWs. EPA is establishing PSES for this industry to
prevent pass-through of the same pollutants controlled by BAT from POTWs to waters of
the U.S.
The Agency is proposing pretreatment standards for existing sources (PSES)
based on the same technologies as proposed for BPT and BAT for 78 of the 87 priority
and non-conventional pollutants regulated under BAT for Regulatory Option 1 (the
combination of Metals Option 3, Oils Option 2, and Organics Option 1) and 81 of the 87
priority pollutants regulated under BAT for Regulatory Option 2 (the combination of Metals
Option 3, Oils Option 3, and Organics Option 1). A discussion of the pollutants excluded
from PSES are included in Section 5. These standards would apply to existing facilities
in all subcategories of the Centralized Waste Treatment Industry that indirectly discharge
wastewater to publicly-owned treatment works (POTWs). These limitations were
developed based on the same technologies as proposed today for BPT/BAT, as
applicable to each of the affected subcategories. PSES set at these points would prevent
pass-through of pollutants, help control sludge contamination and reduce air emissions.
The Agency considered the age, size, processes, other engineering factors, and
non-water quality environmental impacts pertinent to facilities in developing PSES. The
Agency did not identify any basis for establishing different PSES limitations based on age,
size, processes, or other engineering factors.
8-21
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8.6 PSAfS
Section 307(c) of the Act requires EPA to promulgate pretreatment standards for
new sources (PSNS) at the same time it promulgates new source performance standards
(NSPS). New indirect discharging facilities, like new direct discharging facilities, have the
opportunity to incorporate the best available demonstrated technologies, process
changes, in-facility controls, and end-of-pipe treatment technologies.
EPA determined that a broad range of pollutants discharged by Centralized Waste
Treatment Industry facilities pass-through POTWs. The same technologies discussed
previously for BAT, NSPS, and PSES are available as the basis for PSNS.
EPA is proposing that pretreatment standards for new sources be set equal to
NSPS for priority and non-conventional pollutants for all subcategories. The Agency is
proposing to establish PSNS for the same priority and non-conventional pollutants as are
being proposed for NSPS. EPA considered the cost of the proposed PSNS technology
for new facilities. EPA concluded that such costs are not so great as to present a barrier
to entry, as demonstrated by the fact that currently operating facilities are using these
technologies.
8.7 COST OF TECHNOLOGY OPTIONS
The Agency estimated the cost for Centralized Waste Treatment facilities to
achieve each of the proposed effluent limitations and standards. All cost estimates in this
section are expressed in 1993 dollars. The cost components reported in this section
represent estimates of the investment cost of purchasing and installing equipment, the
annual operating and maintenance costs associated with that equipment, additional costs
for discharge monitoring, and costs for facilities to modify existing RCRA permits. The
following sections present costs for BPT, BCT, BAT, and PSES.
8-22
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8.7.1 Proposed BPT Costs
The, Agency, estimated the cost of implementing the proposed BPT effluent
limitations guidelines and standards by calculating the engineering costs of meeting the
required effluent limitations for each direct discharging CWT. This facility-specific
engineering cost assessment for BPT began with a review of present waste treatment
technologies. For facilities without a treatment technology in-place equivalent to the BPT
technology, the EPA estimated the cost to upgrade its treatment technology, to use
additional treatment chemicals to achieve the new discharge standards, and to employ
additional personnel, where applicable, for the option. The only facilities given no cost
for compliance were facilities with the treatment-in-place prescribed for that option.
Details pertaining to the development of the technology costs are included in Section 7.
The capital expenditures for the process change component of proposed BPT are
estimated to be $17.7 million with annual O&M costs of $14.3 million for Regulatory
Option 1 (the combination of Metals Option 3, Oils Option 2, and Organics Option 1) and
$20.6 million with annual O&M costs of $21.7 million for Regulatory Option 2 (the
combination of Metals Option 3, Oils Option 3, and Organics Option 1). Table 8-4
summarizes, by subcategory, the capital expenditures and annual O&M costs for
implementing proposed BPT.
Table 8-4. Cost of Implementing Proposed BPT Regulations [in millions of 1993 dollars]
Subcategory
Metals Treatment and Recovery
Oils Treatment and Recovery -
Regulatory Option 1
Oils Treatment and Recovery -
Regulatory Option 2
Organics Treatment
Regulatory Option 1
R^ni il^torv Ontion ^
Number of
Facilities1
12
4
4
6
16
16
Capital
Costs
15.4
1.02
3.84
1.32
17.7
906
Annual
O&M Costs
10.5
0.779
8.15
3.06
14.3
91.7
1Because some direct dischargers include operations in more than one subcategory, the sum of the facilities
with operations in any one subcategory exceeds the total number of facilities.
8-23
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8.7.2 Proposed BCT/BAT Costs
The Agency estimated that there would be no cost of compliance for implementing
proposed BCT/BAT, because the technology is identical to BPT and the costs are
included with proposed BPT.
8.7.3 Proposed PSES Costs
The Agency estimated the cost for implementing proposed PSES with the same
assumptions and methodology used to estimate cost of implementing BPT. The capital
expenditures for the process change component of PSES are estimated to be $43.8
million with annual O&M costs of $26.8 million for Regulatory Option 1 (the combination
of Metals Option 3, Oils Option 2, and Organics Option 1) and $52.6 million with annual
O&M costs of $45.9 million for Regulatory Option 2 (the combination of Metals Option 3,
Oils Option 3, and Organics Option 1). Table 8-5 summarizes, by subcategory, the
capital expenditures and annual O&M costs for implementing proposed PSES.
Table 8-5. Cost of Implementing Proposed PSES Regulations [in millions of 1993 dollars]
Subcategory
Metals Treatment and Recovery
Oils Treatment and Recovery -
Regulatory Option 1
Oils Treatment and Recovery -
Regulatory Option 2
Organics Treatment
Regulatory Option 1
Regulatory Option 2
Number
of
Facilities
44
31
31
16
56
56
Capital
Costs
27.598
4.084
12.607
10.736
43.8
52.6
Annual
O&M Costs
22.267
2.294
20.894
1.365
26.8
45.9
Because some indirect dischargers include operations in more than one subcategory, the sum of the facilities
with operations in any one subcategory exceeds the total number of facilities.
8-24
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8.8 POLLUTANT REDUCTIONS
8.8.1 Conventional Pollutant Reductions
EPA has calculated how much adoption of the proposed BPT/BCT limitations
would reduce the total quantity of conventional pollutants that are discharged. To do this,
for each subcategory, the Agency developed an estimate of the long-term average
loading (LTA) of BOD5, TSS, and Oil and Grease that would be discharged after the
implementation of BPT. Next, these BPT/BCT LTAs for BOD5, TSS, and Oil and Grease
were multiplied by 1989 wastewater flows for each direct discharging facility in the
subcategory to calculate BPT/BCT mass discharge loadings for BOD5, TSS, and Oil and
Grease for each facility. The BPT/BCT mass discharge loadings were subtracted from
the estimated current loadings to calculate the pollutant reductions for each facility. Each
subcategory's BPT/BCT pollutant reduction was summed to estimate the total facility's
pollutant reduction for those facilities treating wastes in multiple subcategories.
Subcategory reductions, obviously, were obtained by summing individual subcategory
results. The Agency estimates that the proposed regulations will reduce BOD5 discharges
by approximately 34.5 million pounds per year for Regulatory Option 1 (the combination
of Metals Option 3, Oils Option 2, and Organics Option 1) and 36.9 million pounds per
year for Regulatory Option 2 (the combination of Metals Option 3, Oils Option 3, and
Organics Option 1); TSS discharges by approximately 30.3 million pounds per year for
both Regulatory Options; and Oil and Grease discharges by approximately 52.4 million
pounds per year for Regulatory Option 1 (the combination of Metals Option 3, Oils Option
2, and Organics Option 1) and 56.9 million pounds per year for Regulatory Option 2 (the
combination of Metals Option 3, Oils Option 3, and Organics Option 1).
8-25
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8.8.2 Priority and Nonconventional Pollutant Reductions
8.8.2.1
Methodology
The proposed BPT, BCT, BAT, and PSES, if promulgated, will also reduce
discharges of priority and non-conventional pollutants. Applying the same methodology
used to estimate conventional pollutant reductions attributable to application of BPT/BCT
control technology, EPA has also estimated priority and non-conventional pollutant
reductions for each facility by subcategory. Because EPA has proposed BAT limitations
equivalent to BPT, there are obviously no further pollutant reductions associated with BAT
limitations.
Current loadings were estimated using data collected by the Agency in the field
sampling program and from the questionnaire data supplied by the industry. For many
facilities, data were not available for all pollutants of concern or without the addition of
other non-CWT wastewater. Therefore, methodologies were developed to estimate
current performance for each subcategory. Performance of on-site treatment
technologies was assessed with wastewater permit information and monitoring data
supplied in the 1991 Waste Treatment Industry Questionnaire and the Detailed
Monitoring Questionnaire.
8.8.2.2
Direct Facility Discharges (BPT/BAT)
The estimated reductions in pollutants directly discharged in treated final effluent
resulting from implementation of proposed BPT/BAT are listed in Table 8-6. Pollutant
reductions are presented for Regulatory Option 1 (the combination of Metals Option 3,
Oils Option 2, and Organics Option 1) and Regulatory Option 2 (the combination of
Metals Option 3, Oils Option 3, and Organics Option 1). The Agency estimates that
proposed BPT/BAT regulations will reduce direct facility discharges of priority, and non-
8-26
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conventional pollutants by 56.1 million pounds per year for Regulatory Option 1 and 58.2
million pounds per year for Regulatory Option 2.
Table 8-6. Reduction in Direct Discharge of Priority and Nonconventional Pollutants
After Implementation of Proposed BPT/BAT Regulations
(units = Ibs/year)
Subcategory
Metals Treatment and Recovery
Oils Treatment and Recovery -
Regulatory Option 1
Oils Treatment and Recovery -
Regulatory Option 2
Organics Treatment
Regulatory Option 1
Regulatory Option 2
Metal
Compounds
871,832
294,543
319,847
3,065,679
4,232,054
4,257,358
Organic
Compounds
245,525
556,627
610,937
O1
802,153
856,462
all facilities had the treatment-in-place for removal of organic compounds.
8.8.2.3
PSES Effluent Discharges to POTWs
The estimated reductions in pollutants indirectly discharged to POTWs resulting
from implementation of proposed PSES are listed in Table 8-7. Pollutant reductions are
presented for Regulatory Option 1 (the combination of Metals Option 3, Oils Option 2, and
Organics Option 1) and Regulatory Option 2 (the combination of Metals Option 3, Oils
Option 3, and Organics Option 1). The Agency estimates that proposed PSES
regulations will reduce indirect facility discharge to POTWs by 76.8 million pounds per
year for Regulatory Option 1 and for Regulatory Option 2 81.9 million pounds per year.
8-27
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Table 8-7. Reduction in Indirect Discharge of Priority and Nonconventional Pollutants
After Implementation of Proposed PSES Regulations
(units = Ibs/year)
Subcategory
Metals Treatment and Recovery
Oils Treatment and Recovery - Regulatory
Option 1
Oils Treatment and Recovery - Regulatory
Option 2
Organics Treatment
Regulatory Option 1
(with Oils Option 2)
Regulatory Option 2
(with Oils Option 3)
Metal
Compounds
428,040
709,834
771,668
415,812
1,553,686
1,615,520
Organic
Compounds
120,545
1,341,439
1,474,708
3,521,560
4,983,544
5,116,813
8-28
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SECTION 9
NON-WATER QUALITY IMPACTS
During wastewater treatment, the pollutants of concern are either removed from
the waste stream or destroyed. If the pollutants are removed, they are transferred from
the water to another medium as a treatment residual. Subsequent disposition of these
wastewater treatment residuals results in non-water quality impacts. The removal of
organic pollutants from the wastewater also prevents them from being released into the
atmosphere, which affects air quality.
Wastewater treatment also results in other, non-water, non-residual, impacts.
These impacts are the consumption of energy used to power the wastewater treatment
equipment, and the use of additional personnel to provide the wastewater treatment
equipment operating labor.
Sections 304(b) and 306 of the Clean Water Act require EPA to consider the non-
water quality environmental impacts and energy requirements of certain regulations.
Pursuant to these requirements, EPA has considered the effect of the CWT BPT, BCT,
BAT, NSPS, PSES, and PSNS regulations on air pollution, solid waste generation, and
energy consumption. Additionally, EPA has considered the positive effect of employment
gains for the industry resulting from the increased operating labor requirements of these
regulations.
9.1 AIR POLLUTION
CWT facilities treat waste streams which contain significant concentrations of
volatile organic compounds (VOCs). These waste streams usually pass through
collection and treatment units that are open to the atmosphere. This exposure may result
in the volatilization of VOCs from the wastewater.
No negative air quality impacts are anticipated as a result of the CWT regulations.
Rather, the implementation of technologies for compliance with the regulations should
9-1
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reduce the emissions of VOCs into the atmosphere. In the Organics Subcategory
treatment trains, air stripping and granular activated carbon (GAG) adsorption treatment
results in the removal of VOCs from the wastewater. In the Oils Subcategory treatment
trains, the ultrafiltration, reverse osmosis, and GAG treatment units also provide VOC
removals. These VOCs, instead of being released into the air, are transferred to a
treatment residual. Taken here as a positive impact, removal of these VOCs results in
a negative impact in terms of solid and aqueous treatment residuals generation. Table
9-1 presents the estimated reductions in VOC emissions resulting from compliance with
the CWT regulations. Solid and aqueous impacts are discussed later.
Table 9-1. Air Pollution Reductions for the CWT Industry
CWT
Subcategory
Oils
Organics
Option
2
3
4
1
2
VOCs Removed (million Ibs/year)
Indirects
63.7783
82.8056
85.1056
1 ,302.6800
1 ,303.7248
Directs
24.2875
33.1970
34.3239
708.3285
709.0126
Total
88.0658
116.0028
119.4295
2,01 1 .0085
2,012.7374
9.2 SOLID AND OTHER AQUEOUS WASTE
Solid and other aqueous waste would be generated by several of the wastewater
treatment technologies expected to be implemented to comply with the CWT regulations.
The costs for disposal of these other waste residuals were included in the compliance
cost estimates prepared for the regulatory options.
The solid and other aqueous waste treatment residuals are filter cake, reverse
osmosis and uitrafiltration concentrate, spent activated carbon, and deactivated air
9-2
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stripper oxidizer catalyst. These residuals are described and quantified in the following
discussions.
9.2.1 Filter Cake
In the CWT Metals Subcategory treatment trains, hydroxide precipitation of metals
generates a sludge residual. This sludge is dewatered, and the resultant filter cake is
disposed or recycled. At one CWT facility that EPA sampled during this project, the use
of selective metals precipitation allows for the reclamation of the metal-bearing filter cake.
Therefore, the total quantities of metals treatment filter cake estimated for CWT
compliance may not necessarily require disposal. However, in the CWT economic
evaluation, contract hauling for off-site disposal in a Subtitle C or D landfill was the
method costed. In the Organics Subcategory treatment train, the sequencing batch
reactor (SBR) produces a biological treatment sludge which is also dewatered and
disposed off-site.
It is estimated that compliance with Metals Options 1,2, or 3 and Organics Options
1 or 2 would result in the disposal of 3.9 million gallons, or 39 million pounds, of
hazardous and nonhazardous filter cake. The itemized estimated filter cake generation
for the CWT Industry is presented in Table 9-2.
9-3
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Table 9-2. Filter Cake Generation for the CWT Industry
CWT
Subcategory
Organics
Metals
Option
1
2
1
2
3
Filter Cake Generated (million gal/year)
Hazardous
Indirect
0.1870
0.1870
0.9905
0.9905
0.9905
Direct
0
0
1.2439
1.2439
1 .2439
Total
0.1870
0.1870
2.2344
2.2344
2.2344
Nonhazardous
Indirect
0.3798
0.3798
0.4879
0.4879
0.4879
Direct
0
0
0.6126
0.6126
0.6126
Total
0.3798
0.3798
1.1005
1.1005
1.1005
9.2.2 Reverse Osmosis Concentrate
In the Oils Subcategory treatment trains, reverse osmosis (RO) treatment of oily
streams results in the generation of a concentrated residual stream. At the CWT facility
which uses this technology, the concentrated residual is either recycled via fuel-blending
or disposed. Therefore, the total quantities of RO concentrate estimated for CWT
compliance may not necessarily require disposal. However, in the CWT economic
evaluation, contract hauling for off-site disposal was. costed. The estimated RO
concentrate generation for the CWT Industry is presented in Table 9-3.
Table 9-3. Reverse Osmosis Concentrate Generation for the CWT Industry
CWT Oils Subcategory Option
2
3
4
RO Concentrate Generated (MGal/year)
Indirects
0
42.2458
42.2458
Directs
0
15.9214
15.9214
Total
0
58.1672
58.1672
9-4
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9.2.3 Ultrafiltration Concentrate
In the Oils Subcategory treatment trains, ultrafiltration (UF) treatment of oily
streams results in the generation of a concentrated residual stream. At the CWT facility
which uses this technology, the concentrated residual is either recycled via fuel-blending
or disposed. Therefore, the total quantities of UF concentrate estimated for CWT
compliance may not necessarily require disposal. However, in the CWT economic
evaluation, contract hauling for off-site disposal was costed. The estimated UF
concentrate generation for the CWT Industry is presented in Table 9-4.
Table 9-4. Ultrafiltration Concentrate Generation for the CWT Industry
CWT Oils Subcategory
Option
2
3
4
UF Concentrate Generated (MGal/year)
Indirects
2.9864
2.9864
2.9864
Directs
1.1372
1.1372
1.1372
Total
4.1236
4.1236
4.1236
9.2.4 Spent Carbon
In the Oils and Organics Subcategories treatment trains, granular activated carbon
(GAG) adsorption treatment of waste streams results in the generation of exhausted, or
spent activated carbon. In the CWT economic evaluation, removal of the spent carbon
for regeneration by a vendor was costed. The estimated activated carbon usage for the
CWT Industry is presented in Table 9-5.
9-5
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Table 9-5. Activated Carbon Requirements for the CWT Industry
CWT Subcategory
Oils
Organics
Option
2
3
4
1
2
Carbon Usage (million Ibs/year)
Indirects
0
1 .0794
2.1624
0
5.4402
Directs
0
0.5289
4.4126
0
3.5618
Total
0
1 .6083
6.5750
0
9.0020
9.2.5 Air Stripper Oxidizer Catalyst
In the Organics Subcategory treatment train, air stripping treatment of waste
streams results in the generation of a contaminated off-gas, which requires the application
of an air pollution control device. A catalytic oxidizer was costed for the CWT economic
evaluation. Over time, its catalyst becomes deactivated; the replacement of the spent
catalyst by a vendor was costed. The estimated air stripper catalyst usage for the CWT
Industry is presented in Table 9-6.
Table 9-6. Air Stripper Oxidizer Catalyst Requirements for the CWT Industry
CWT Organics Subcategory
Option
1
2
Catalyst Usage (Ibs/year)
Indirects
109.1
109.1
Directs
59.4
59.4
Total
168.5
168.5
9-6
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9.3 ENERGY REQUIREMENTS
In all of the CWT Subcategories, operation of wastewater treatment equipment
results in the consumption of energy. This energy is used to power pumps, mixers, and
other equipment components, to power lighting and controls, and to generate heat. The
itemized estimated energy usage for the CWT Industry is presented in Table 9-7. As can
be seen in this table, the proposed CWT Regulatory Option 1 (the combination of Oils
Option 2, Organics Option 1, Cyanide Waste Pretreatment, and Metals Option 3) would
require the consumption of 17.71 million kilowatt-hours per year of electricity. This is the
equivalent of 9,925 barrels per year of #2 fuel oil. The proposed CWT Regulatory Option
2 (the combination of Oils Option 3, Organics Option 1, Cyanide Waste Pretreatment, and
Metals Option 3) would require the consumption of 21.95 million kilowatt-hours per year
of electricity, or 12,300 barrels per year of #2 fuel oil.
Table 9-7. Energy Requirements for the CWT Industry
CWT Subcategory
Oils
Organics
Cyanide Waste
Pretreatment
Metals
Option
2
3
4
1
2
2
1
2
3 '
Energy Usage (kwhr/year)
Indirects
5,799,279
8,872,953
8,918,041
619,642
639,494
219,603
99,790
3,553,280
4,117,529
Directs
3,566,654
4,735,779
4,763,509
294,821
307,819
55,683
137,339
2,649,986
3,035,628
Total
9,365,933
13,608,732
13,681,550
914,463
947,313
275,286
237,129
6,203,266
7,153,157
9-7
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9.4 LABOR REQUIREMENTS
The installation of new wastewater treatment equipment for compliance with the
CWT regulations would result in increased operating labor requirements for GWT facilities.
It is estimated that compliance with the CWT regulations would result in industry-wide
employment gains; the estimated labor needs are presented in Table 9-8.
Table 9-8. Labor Requirements for the CWT Industry
CWT Subcategory
Oils
Organics
Cyanide Waste
Pretreatment
Metals
Option
2
3
4
1
2
2
1
2
3
Operating Labor Requirements
Indirect Dischargers
(hours/yr)
14,560
58,630
91 ,480
48,234
60,279
17,520
22,456
1 ,062,640
1 ,089,940
(men/yr)
7.3
29.3
45.8
24.1
30.1
8.6
11.2
531.3
545.0
Direct Dischargers
(hours/yr)
2,080
8,540
12,920
16,266
22,836
2,190
15,242
223,580
229,820
(men/yr)
1.0
4.3
6.5
8.1
11.4
1.1
7.6
111.8
114.9
9-8
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SECTION 10
IMPLEMENTATION
Implementation of a regulation is the final step in the regulatory process. If a
regulation is not effectively implemented, the removals and environmental benefits
estimated for the regulation may not be achieved.
In discussions with permit writers and pretreatment authorities, many stated that
close communication with CWT facilities was important for effective implementation of
discharge permits. Due to the difficulty in treating the concentrated waste streams
identified in the CWT Industry, many facilities also maintain close communication with the
waste generator. Many CWT facilities work with generators to ensure the waste received
for treatment is, in fact, substantially similar to that reported in the original paperwork for
accepting the waste for treatment. CWT facilities also work with generators to reduce the
mixing of various waste streams. The facility on which the proposed Metals Subcategory
limitations are based asked waste generators not to mix wastes from various processes.
This assisted the process of selective metals precipitation. Therefore, close
communication among permit writers/pretreatment authorities, waste generators, and
CWT facilities is an important aspect in effective implementation of the effluent guidelines
limitations and standards.
10.1 APPLICABLE WASTE STREAMS
Effective implementation of the regulation depends on accurate determination of
which waste streams are covered by the each subcategory of the regulation and careful
management of individual waste streams by the generators of the waste and the CWT
facility. Section 4 describes the sources of wastewater for the CWT Industry including
waste receipts; tanker truck, trailer/roll-off bins and drum wash water; solubilization water;
and contaminated stormwater. One of the most difficult wastewater sources to identify
is contaminated stormwater. Many facilities discharge stormwater, but not necessarily
10-1
-------
contaminated stormwater. Contaminated stormwater is defined as any wastewater which
comes in direct contact with waste receipts and waste handling or treatment areas.
During site visits at CWT facilities, EPA identified many circumstances in which
uncontaminated stormwater is added to CWT wastewater for treatment or after treatment
but prior to effluent discharge monitoring. In most cases, the addition of stormwater
probably resulted in dilution of the waste stream. In some cases, stormwater,
contaminated or uncontaminated, was used as solubilization water for wastes in the solid
phase to render the waste treatable in order to reduce water costs.
10.2 DETERMINATION OF SUBCATEGORIES
Since 30 percent of facilities receive wastes which may be classified in more than
one subcategory, one of the most important aspects of implementation is the
determination of which subcategory's limitations are applicable to a facility's operation.
EPA recommends that permit writers and pretreatment authorities work with CWT
facilities to assess the process for which wastes are accepted for treatment. In Section
3, a process that many CWT facilities used for waste acceptance is outlined. This
process ensures that CWT facilities are aware of the types of waste accepted for
treatment and the types of pollutants which are contained in the waste.
After characterizing wastes accepted for treatment, the pollutant concentrations
listed in Table 10-1 may be used as a guide for determining the subcategory of wastes
accepted for treatment. It is important to note that various pollutants were detected in all
three subcategories. Organic pollutants were found in the Metals and Oils Subcategories
and metal pollutants were detected in the Organics Subcategory. Waste stream
subcategories are determined by the concentration levels reported. In developing the
regulation, EPA did not find any single waste receipt which could be classified in multiple
subcategories. This most probably would occur if waste streams were mixed by the waste
generator.
10-2
-------
Table 10-1. Pollutant Concentrations for Determination of Subcategory
Metals Subcategory
Oils Subcategory
Organics Subcategory
If any of the following
metals are found at a
concentration greater
than the values listed
below:
Aluminum
Antimony
Arsenic
Barium
Cadmium
Chromium
Cobalt
Copper
Lead
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Tin
Titanium
Zinc
1993mg/l
1.6mg/l
0.7 mg/l
7.1 mg/l
0.5 mg/l
7.2 mg/l
0.9 mg/l
80.0 mg/l
22.0 mg/l
250 mg/l
20.4 mg/l
0.007 mg/l
13 mg/l
62 mg/l
6.3 mg/l
21 mg/l
94.5 mg/l
If Total Cyanide is
greater than 68 mg/l, in-
facility monitoring after
CN pretreatment is
required.
If the Oil & Grease
concentration is greater
than 700 mg/l.
If concentrations
detected are less than
the cut-offs for the
Metals and Oils
Subcategory.
Permit writers and pretreatment authorities should also review the types of
operations at a facility. Facilities which operate Oils Recovery and Metals Recovery are
included in the Oils Subcategory and Metals Subcategory, respectively. Oils recovery
processes are typically chemical emulsion breaking processes where the addition of acid
or heat are used to break stable oil-water emulsions. During the EPA sampling program,
10-3
-------
stable oil-water emulsions were not sampled prior to treatment because approved
analytical methods were not applicable for the waste type. Any wastewater generated
from an Oils Recovery process is classified as Oils Subcategory wastewater.
10.3 ESTABLISHING LIMITATIONS AND STANDARDS FOR FACILITY DISCHARGES
10.3.1
Facilities with One Operation
The simplest case for establishing discharge limitations and standards is for
facilities classified in one CWT subcategory. If all water discharged is classified as CWT
wastewater, the limitations for the subcategory of concern are applied at the outfall or
discharge point. Permit writers or pretreatment authorities should review the facility
wastewater sources to determine if any portion of the wastewater discharge results from
the treatment or addition of non-CWT wastewater (i.e., stormwater or other industrial
wastewater). The permit writer or pretreatment authority should determine the effluent
discharge limitation for each pollutant by flow-proportioning CWT limitations as illustrated
in Equation 10-1.
tlMIT'
_XCWT*FLOWCWT+XNON-CWT*FLOWNON-CWT
FLOW.
(40-1)
TOTAL
where:
XUMIT = Permit Discharge Concentration,
XCWT = CWT Limitation,
FLOWCWT = CWT Flow,
XNON-CWT = Limitation for Non-CWT Waste Stream, and
= Non-CWT Flow.
10-4
-------
If the waste stream is added after treatment of the CWT waste stream occurs, the
permit writer or pretreatment authority many establish the discharge limitations prior to
the addition of the non-CWT waste stream.
10.3.2
Facilities with Operations Classified in Multiple Subcategories
After facilities have been classified in multiple subcategories, permits may be
established based on site specific configurations. Facilities which have separate
treatment systems for each of the waste steams may monitor for compliance with the
limitations after each of the separate treatment systems or may monitor for compliance
after mixing of the waste streams for discharge. When facilities mix the wastewater from
each separate treatment system, Equation 10-2 may be used to determine the discharge
limitations for each pollutant. CWT facilities that mix the wastewater prior to discharge
but after treatment must demonstrate that limitations are being achieved through
treatment not dilution. Therefore, if any pollutants are not detected at the discharge point,
analysis of the waste streams prior to mixing is required to ensure compliance with the
limitations and standards.
XMETAL*FLOWMETAL+XOILS*FLOWOILS+XORGANICS*FLOWORGANICS
'•LIMIT"
FLOW.
(50-1)
TOTAL
where:
XLIMIT = Permit Discharge Concentration,
XMETALS = Metals Subcategory Limitation,
FLOWMETALS = Metals Subcategory Flow,
XQILS = Oils Subcategory Limitation,
FLOWOILS = Oils Subcategory Flow,
10-5
-------
XORGANICS = Organics Subcategory Limitation, and
= Organics Subcategory Flow.
Facilities which mix waste prior to complete treatment of the wastewater may also
use Equation 10-2 to determine the discharge limitations for each pollutant, but
monitoring for compliance is more difficult. The CWT facility must demonstrate to the
permit writer or pretreatment authority that the treatment system can achieve the effluent
limitations through treatment, not dilution.
The first step in determining if a treatment system can achieve the limitations is
analyzing the waste stream prior to addition with other wastes. If pollutants of concern
for the waste type are detected after mixing of waste streams and the effluent discharge
limitations are met, the CWT facility has demonstrated compliance. If pollutants of
concern for the waste type are not detected after mixing with other wastes, the CWT
facility must demonstrate to the permit writer or pretreatment authority that the treatment
system can achieve the effluent limitations and standards. CWT facilities may
demonstrate that treatment systems can achieve the effluent limitations and standards in
various ways. If the treatment facility has any treatability studies for the design of the
treatment system which contain data on pollutant concentrations, this information may be
used. Facilities may also submit data from text books which discuss the types of
pollutants which are removed from the treatment technologies in place. For example, a
facility classified in both the Metals and Organics subcategories may have biological
treatment as the on-site treatment technology. Various text books on the design of
biological treatment systems discuss the pollutants removed and the possible treatment
levels, but metal pollutants are not typically treated in biological treatment systems to any
appreciable level. Therefore, the facility, in the above case, would be required to add
treatment for the metals portion of the waste stream to demonstrate compliance with the
effluent limitations and standards.
EPA identified many circumstances where additional treatment may be necessary
to demonstrate compliance. Many facilities accept metal-bearing and oily wastes. The
10-6
-------
wastewaterfrom Oils Recovery is typically mixed with the metal-bearing waste stream for
treatment in a metal precipitation process. The metals precipitation process may treat the
metal compounds detected in both waste streams, but will not treat the organic
constituents present in the oily waste stream. In many instances, the oily wastewater flow
is relatively small in comparison to the metal-bearing waste stream and mixing of the
waste streams results in pollutants of concern not being detected. Therefore, when
establishing the permit for such an operation, a facility would be required to demonstrate
compliance with the effluent limitations by submitting treatability data or technical
references to the permit writer or pretreatment authority illustrating that the effluent
limitations are achievable in the on-site treatment system. If the facility is unable to
demonstrate compliance for the on-site treatment system, additional treatment would be
necessary to effectively treat the pollutants which are not treated in the present treatment
system.
10-7
-------
-------
INDEX
Activated Sludge
Technology Description (6-51)
Treatment Performance (6-52)
Air Pollution Control Scrubber Blow-down (4-3)
Air Pollution Reduction Impacts (9-1)
Air Stripping
Costs (7-21)
Land Requirements (7-22)
Oxidizer Catalyst Replacement Impacts (9-5)
Technology Description (6-17)
Treatment Performance (6-20)
Applicable Waste Streams (10-1)
Aqueous Waste Disposal Impacts (9-2)
BAT (1-3, 8-19)
Costs (8-24)
BCT (1-2, 8-19)
Costs (8-24)
Belt Pressure Filtration
Technology Description (6-68)
Treatment Performance (6-70)
Biotowers
Technology Description (6-49)
Treatment Performance (6-51)
BOD (4-7)
Influent Concentration (4-8)
BPT(1-1)
Costs (8-23)
Established (8-1)
Limitations - Metals Subcategory (8-6)
Limitations - Oils Subcategory (8-11)
Limitations - Organics Subcategory (8-16)
Metals Subcategory - Rationale (8-3)
Oils Subcategory - Rationale (8-9)
Organics Subcategory - Rationale (8-14)
INDEX-1
-------
BPT (continued)
Technology Options - Metals Subcategory (8-4)
Technology Options - Oils Subcategory (8-9)
Technology Options - Organics Subcategory (8-14)
Carbon Adsorption
Costs (7-24)
Land Requirements (7-25)
Spent Carbon Replacement Impacts (9-5)
Technology Description (6-24)
Treatment Performance (6-26)
Chemical Precipitation
Costs (7-4)
Land Requirements (7-8)
Technology Description (6-2)
Treatment Performance (6-5)
Chromium Reduction
Costs (7-28)
Land Requirements (7-30)
Technology Description (6-33)
Treatment Performance (6-36)
Clarification
Costs (7-14)
Land Requirements (7-16)
Technology Description (6-10)
Treatment Performance (6-10)
Cost Factors
Capital (7-2)
O & M (7-3)
Costs
BCT/BAT (8-24)
BPT (8-23)
Capital, Explanation of (7-2)
Filter Cake Disposal (7-36)
Implementation (Es-4)
INDEX-2
-------
Costs (continued)
Land (7-41)
Monitoring (7-38)
0 & M, Explanation of (7-2)
PSES (8-24)
RCRA Permit Modification (7-40)
Retrofit (7-38)
Technology Options (8-22)
Current Performance (4-13)
Metals Subcategory (4-13, 4-16)
Oils Subcategory (4-18)
Organics Subcategory (4-21)
CWT Industry
General Information (3-2)
Location (3-2)
Number of Facilities (3-2)
Other Industrial Operations (3-3)
Cyanide Destruction
Costs (7-26)
Land Requirements (7-27)
Technology Description (6-30)
Treatment Performance (6-33)
Discharge Information
Comparison of Total Facility Discharge (4-4)
Distribution of Facilities (3-8)
Options Used (3-8)
Pollutants (4-13)
Quantity Discharged (3-9)
Quantity Discharged in 1989 (3-9)
Dissolved Air Flotation
Technology Description (6-42)
Treatment Performance (6-45)
Electrolytic Recovery
Technology Description (6-36)
Treatment Performance (6-37)
INDEX-3
-------
Emulsion Breaking
Technology Description (6-14)
Treatment Performance (6-16)
Energy Requirements Impacts (9-6)
Equalization
Costs (7-20)
Land Requirements (7-21)
Technology Description (6-16)
Treatment Performance (6-17)
Equipment Washes (4-3)
Facility Statistics
Wastes Receipts (3-3)
Filter Cake Disposal
Costs (7-36)
Impacts (9-3)
Gravity Separation
Technology Description (6-41)
Treatment Performance (6-42)
Impacts
Air Pollution Reductions (9-1)
Air Stripper Oxidizer Catalyst Replacement (9-5)
Energy Requirements (9-6)
Filter Cake Disposal (9-3)
Labor Requirements (9-7)
Non-water Quality (9-1)
Reverse Osmosis Concentrate Disposal (9-3)
Solid and Other Aqueous Waste Disposal (9-2)
Spent Carbon Replacement (9-5)
Ultrafiltration Concentrate Disposal (9-4)
Implementation (10-1)
Applicable Waste Streams (10-1)
Determination of Subcategories (10-2)
Establishment of Limitations (10-4)
INDEX-4
-------
Influent Concentrations
Metal Pollutants (4-10)
Organic Pollutants (4-11)
Pollutant Parameters (4-8)
Ion Exchange
Technology Description (6-37)
Treatment Performance (6-41)
Laboratory-derived Wastewater (4-3)
Labor Requirements Impacts (9-7)
Lancy Filtration
Technology Description (6-59)
Treatment Performance (6-60)
Land Costs (7-41)
Limitations
Cyanide Pretreatment (8-6)
Metals Subcategory (8-6)
Oils Subcategory (8-11)
Organics Subcategory (8-16)
Technology Basis (Es-2)
Liquid Carbon Dioxide Extraction
Technology Description (6-62)
Treatment Performance (6-64)
Metals Subcategory
BPT - Rationale (8-3)
Current Performance (4-13, 4-16)
Influent Concentrations (4-8, 4-10, 4-11)
Pollutants Selected for Regulation (5-3)
Technology Options (8-4)
Monitoring Costs (7-38)
Multi-media Filtration
Costs (7-23)
Land Requirements (7-24)
Technology Description (6-21)
Treatment Performance (6-22)
Non-water Quality Impacts (9-1)
NSPS (1-3, 8-20)
INDEX-5
-------
Oil and Grease (4-7)
Influent Concentration (4-8)
Oils Subcategory
BPT - Rationale (8-9)
Current Performance (4-18)
Influent Concentrations (4-8, 4-10, 4-11)
Pollutants Selected for Regulation (5-3)
Technology Options (8-9)
Organics Subcategory
BPT-Rationale (8-14)
Current Performance (4-21)
Influent Concentrations (4-8, 4-10, 4-11)
Pollutants Selected for Regulation (5-3)
Technology Options (8-14)
Pass-through Analysis
50 Potw Study Data Base (5-8)
Approach (5-7)
Data Editing (5-9)
Final Potw Removals (5-12)
Results (5-14)
Results - Metals Subcategory (5-16)
Results - Oils Subcategory (5-17)
Results - Organics Subcategory (5-18)
RREL Treatability Data Base (5-9)
Volatile Override (5-15)
pH (4-7)
Pipeline Exclusion (3-3)
Plate and Frame Pressure Filtration - Liquid Stream
Costs (7-16), (7-19)
Land Requirements (7-18), (7-19)
Technology Description (6-12)
Treatment Performance (6-14)
Plate and Frame Pressure Filtration - Sludge Stream
Costs (7-34)
Land Requirements (7-36)
Technology Description (6-66)
INDEX-6
-------
Plate and Frame Pressure Filtration - Sludge Stream (continued)
Treatment Performance (6-68)
Pollutant Reductions (8-25)
BPT (8-26)
Conventional Pollutants (8-25)
Direct Discharges (8-26)
Indirect Discharges (8-27)
Methodology (8-26)
PSES (8-27)
Pollutants Excluded from Regulation
Due to Ineffective Treatment (5-6)
Due to Isolated Detection (5-4)
Due to Low Concentrations (5-4)
Due to No Analysis at Technology Option (5-5)
Pollutants Selected for Regulation (5-3)
For Pretreatment Standards (5-6)
Priority and Non-conventional Pollutants (4-9)
Procedures for Receipt of Waste (3-6)
PSES (1-4, 8-21)
Costs (8-24)
PSNS (1-4, 8-22)
Quantity of Waste (3-6)
Questionnaires
Pre-test (2-3)
1991 Waste Treatment Industry Questionnaire (2-1, 2-2)
Development (2-1)
Distribution (2-4)
DMQ(2-1,2-2)
RCRA Codes (3-4)
RCRA Permit Modification Costs (7-40)
Retrofit Costs (7-38)
Reverse Osmosis
Concentrate Disposal Impacts (9-3)
Costs (7-33)
Land Requirements (7-34)
Technology Description (6-56)
INDEX-7
-------
Reverse Osmosis (continued)
Treatment Performance (6-57)
Sampling Program (2-5)
1989-1993(2-6)
1994(2-9)
Facility Selection Criteria (2-6)
Metal-bearing Waste (2-7)
Oily Wastes (2-7, 2-9)
Organic Wastes (2-8)
Pre-1989 (2-5)
Sampling Episodes Procedures (2-8)
Secondary Precipitation
Costs (7-10)
Land Requirements (7-12)
Treatment Performance (6-5)
Section 304(m) (1-5)
Selective Metals Precipitation
Costs (7-8)
Land Requirements (7-10)
Technology Description (6-3)
Treatment Performance (6-5)
Sequencing Batch Reactors
Costs (7-30)
Land Requirements (7-31)
Technology Description (6-47)
Treatment Performance (6-47)
Sic Code (3-3)
Solid Waste Disposal Impacts (9-2)
Solubilization Water (4-2)
Stormwater
Contaminated (4-3)
Quantity Discharged (4-3)
Subcategories
Determination of (10-2)
Metal-bearing Waste Treatment (3-13)
Oily Waste Treatment (3-13)
INDEX-8
-------
Subcategories (continued)
Organic Waste Treatment (3-14)
Subcategorization (3-10)
Development of Scheme (3-11)
Proposed Scheme (3-12)
Tanker Truck/drum/roll-off Box Washes (4-2)
Tertiary Precipitation
Costs (7-12)
Land Requirements (7-14)
Treatment Performance (6-5)
Treatment Residuals (3-9)
TSS (4-7)
Influent Concentration (4-8)
Ultrafiltration
Concentrate Disposal Impacts (9-4)
Costs (7-31)
Land Requirements (7-32)
Technology Description (6-54)
Treatment Performance (6-56)
Vacuum Filtration
Technology Description (6-70)
Treatment Performance (6-72)
Waste Form Codes (3-5)
Waste Oil Emulsion-breaking Wastewater (4-2, 4-3)
Waste Receipts (3-3, 4-2)
Acceptance Procedures (3-6)
Quantity (3-6)
Wastewater
By Subcategory (4-6)
Characterization (4-6)
Sources (4-1)
1NDEX-9
-------
-------
Appendix A. RCRA and Waste Form Codes Reported by Facilities in 1989
RCRA Codes
D001
D002
D003
D004
D005
D006
D007
D008
D009
D010
D011
D012
D017
D035
F001
F002
F003
Ignitable Waste
Corrosive Waste
Reactive Waste
Arsenic
Barium
Cadmium
Chromium
Lead
Mercury
Selenium
Silver
Endrin(1,2,3,4,10,1O-hexachloro-1,7-epoxy-1,4,4a,5,6,7,8,8a-
oct3hydro-1,4-endo-5,8-dimeth-3no-napthalene)
2,4,5-TP Silvex (2,4,5-trichlorophenixypropionic acid)
Methyl ethyl ketone
The following spent halogenated solvents used in degreasing:
tetrachloroethylene; trichloroethane; carbon tetrachloride and
chlorinated fluorocarbons and all spent solvent mixtures/blends used
in degreasing containing, before use, a total of 10 percent or more
(by volume) of one or more of the above halogenated solvents or
those solvents listed in F002, F004, and F005; and still bottoms from
the recovery of these spent solvents and spent solvent mixtures
The following spent halogenated solvents: tetrachloroethylene; 1,1,1-
trichloroethane; chlorobenzene; 1,1,2-trichloro-1,2,2-trifluoroethane;
ortho-dichlorobenzene; trichloroethane; all spent solvent
mixtures/blends containing, before use, a total of 10 percent or more
(by volume) of one or more of the above halogenated solvents or
those solvents listed in F001, F004, and F005; and still bottoms from
the recovery of these spent solvents and spent solvent mixtures
The following spent nonhalogenated solvents; xylene, acetone, ethyl
acetate, ethyl benzene, ethyl ether, methyl isobutyl ketone, n-butyl
alcohol, cyclohexanone, and methanol; all spent solvent
mixtures/blends containing, before use, one or more of the above
nonhalogenated solvents, and a total of 10 percent or more (by
volume) of one or more of those solvents listed in F001, 002, F004,
and F005; and still bottoms from the recovery of these spent solvents
and spent solvent mixtures.
A-1
-------
Appendix A. RCRA and Waste Form Codes Reported by Facilities in 1989 (continued)
RCRA Codes (continued)
F004
F005
F006
F007
F008
F009
F010
F011
F012
F019
F039
K001
K011
K013
The following spent nonhalogenated solvents: cresols, cresylic acid,
and nitrobenzene; and the still bottoms from the recovery of these
solvents; all spent solvent mixtures/blends containing before use a
total of 10 percent or more (by volume) of one or more of the above
nonhalogenated solvents or those solvents listed in F001, F002, and
F005; and still bottoms from the recovery of these spent solvents and
spent solvent mixtures
The following spent nonhalogenated solvents: toluene, methyl ethyl
ketone, carbon disulfide, isobutanol, pyridine, benzene, 2-
ethoxyethanol, and 2-nitropropane; all spent solvent mixtures/blends
containing, before use, a total of 10 percent or more (by volume) of
one or more of the above nonhalogenated solvents or those solvents
listed in F001, F002, or F004; and still bottoms from the recovery of
these spent solvents and spent solvents mixtures
Wastewater treatment sludges from electroplating operations except
from the following processes: (1) sulfuric acid anodizing of aluminum;
(2) tin plating on carbon steel; (3) zinc plating (segregated basis) on
carbon steel; (4) aluminum or zinc-aluminum plating on carbon steel:
(5) cleaning/stripping associated with tin, zinc, and aluminum plating
on carbon steel; and (6) chemical etching and milling of aluminum
Spent cyanide plating bath solutions from electroplating operations
Plating bath residues from the bottom of plating baths from
electroplating operations in which cyanides are used in the process
Spent stripping and cleaning bath solutions from electroplating
operations in which cyanides are used in the process
Quenching bath residues from oil baths from metal heat treating
operations in which cyanides are used in the process
Spent cyanide solutions from slat bath pot cleaning from metal heat
treating operations
Quenching waste water treatment sludges from metal heat treating
operations in which cyanides are used in the process
Wastewater treatment sludges from the chemical conversion coating
of aluminum
Multi-source leachate
Bottom sediment sludge from the treatment of wastewater from wood
preserving processes that use creosote and/or pentachldrophenol
Bottom stream from the wastewater stripper in the production of
acrylonitrile
Bottom stream from the acetonitrile column in the production of
acrylonitrile
A-2
-------
Appendix A. RCRA and Waste Form Codes Reported by Facilities in 1989 (continued)
RCRA Codes (continued)
K014
K015
K016
K031
K035
K044
K045
K048
K049
K050
K051
K052
K061
K064
K086
K093
K094
K098
K103
K104
P011
P012
P013
P020
P022
Bottoms from the acetonitrile purification column in the production of
acrylonitrile
Still bottoms from the distillation of benzyl chloride
Heavy ends or distillation residues from the production of carbon
tetrachloride
By-product salts generated in the production of MSMA and cacodylic
acid
Wastewater treatment sludges generated in the production of
creosote
Wastewater treatment sludges from the manufacturing and
processing of explosives
Spent carbon from the treatment of wastewater containing explosives
Dissolved air flotation (DAF) float from the petroleum refining industry
Slop oil emulsion solids from the petroleum refining industry
Heat exchanger bundle cleaning sludge from the petroleum refining
industry
API separator sludge from the petroleum refining industry
Tank bottoms (leaded) from the petroleum refining industry
Emission control dust/sludge from the primary production of steel in
electric furnaces
Acid plant blowdown slurry/sludge resulting from the thickening of
blowdown slurry from primary copper production
Solvent washes and sludges, caustic washes and sludges, or water
washes and sludges from cleaning tubs and equipment used in the
formulation of ink from pigments, driers, soaps, and stabilizers
containing chromium and lead
Distillation light ends from the production of phthalic anhydride from
ortho-xylene
Distillation bottoms from the production of phthalic anhydride from
ortho-xylene
Untreated process wastewater from the production of toxaphene
Process residues from aniline extraction from the production of aniline
Combined wastewater streams generated from nitrobenzene/aniline
production
Arsenic pentoxide (t)
Arsenic (III) oxide (t)
Arsenic trioxide (t)
Barium cyanide
Dinoseb, Phenol,2,4-dinitro-6-(1 -methylpropyl)-
Carbon bisulfide (t)
A-3
-------
Appendix A. RCRA and Waste Form Codes Reported by Facilities in 1989 (continued)
RCRA Codes (continued)
P028
P029
P030
P040
P044
P048
P050
P063
P064
P069
P071
P074
P078
P087
P089
P098
P104
P106
P121
P123
U002
U003
Carbon disulfide (t)
Benzene, (chloromethyl)-
Benzyl chloride
Copper cyanides
Cyanides (soluble cyanide salts), not elsewhere specified (t)
0,0-diethy! 0-pyrazinyl phosphorothioate
Phosphorothioic acid, 0,0-diethyl 0-pyrazinyl ester
Dimethoate (t)
Phosphorodithioic acid,
0,0-dimethyl S-[2-(methylamino)-2-oxoethyl]ester (t)
2,4-dinitrophenol
Phenol,2,4-dinitro-
Endosulfan
5-norbornene-2,3-dimethanol,
1,4,5,6,7,7-hexachloro,cyclic sulfite
Hydrocyanic acid
Hydrogen cyanide
Methyl isocyanate
Isocyanic acid, methyl ester
2-methyllactonitrile
Propanenitrile,2-hydroxy-2-methyl-
0,0-dimethyl 0-p-nitrophenyl phosphorothioate
Methyl parathion
Nickel (II) cyanide
Nickel cyanide
Nitrogen (IV) oxide
Nitrogen dioxide
Osmium tetroxide
Osmium oxide
Parathion (t)
Phosphorothiotic acid,0,0-diethyl O-(p-nitrophenyl) ester (t)
Potassium cyanide
Silver cyanide
Sodium cyanide
Zinc cyanide
Toxaphene
Camphene,octachloro-
2-propanone (i)
Acetone (i)
Ethanenitrile (i,t)
A-4
-------
Appendix A. RCRA and Waste Form Codes Reported by Facilities in 1989 (continued)
RCRA Codes (continued)
U008
U009
U012
U019
U020
U031
U044
U045
U052
U057
U069
U080
U092
U098
U105
U106
U107
U113
U118
U122
U125
Acetonitrile (i,t)
2-propenoic acid (i)
Acrylic acid (i)
2-propenenitrile
Acrylonitrile
Benzenamine (i,t)
Aniline (i,t)
Benzene (i,t)
Benzenesulfonyl chloride (c,r)
Benzenesulfonic acid chloride (c,r)
1-butanol (i)
N-butyl alcohol (i)
Methane, trichloro-
Chloroform
Methane,chloro-(i,t)
Methyl chloride (i,t)
Cresylicacid
Cresols
Cyelohexanone (i)
Dibutyl phthalate
1,2-benzenedicarboxylic acid, dibutyl ester
Methane, dichloro-
Methylene chloride
Methanamine, N-methyl-(i)
Dimethylamine (i)
Hydrazine, 1,1 -dimethyl-
1,1 -dimethylhydrazine
2,4-dinotrotoluene
Benzene, 1 -methyl-2,4-dinitro-
2,6-dinitrotoluene
Benzene, 1-methyl-2,6-dinitro
Di-n-octyl phthalate
1-2-benzenedicarboxylicacid, di-n-octyl ester
2-propenoic acid, ethyl ester (i)
Ethyl acrylate (i)
2-propenoic acid, 2-methyl-, ethyl ester
Ethyl methacrylate
Formaldehyde
Methylene oxide
Furfural (i)
A-5
-------
Appendix A. RCRA and Waste Form Codes Reported by Facilities in 1989 (continued)
RCRA Codes (continued)
U134
U135
U139
U140
U150
U151
U154
U159
U161
U162
U188
U190
U205
U210
U213
U220
U226
U228
U239
2-furancarboxaldehyde (i)
Hydrogen fluoride (c,t)
Hydrofluoric acid (c,t)
Sulfur hydride
Hydrogen sulfide
Ferric dextran
Iron dextran
1-propanol, 2-methyl- (i,t)
Isobutyl alcohol (i,t)
Melphalan
Alanine, 3-[p-bis(2-chloroethyl)amino] phenyl-,L-
Mercury
Methanol (i)
Methyl alcohol (i)
Methyl ethyl ketone (i,t)
2-butanone (i,t)
4-methyl-2-pentanone (i)
Methyl isobutyl ketone (i)
2-propenoic acid,2-methyl-,methyl ester (i,t) ,
Methyl methacrylate (i,t)
Phenol
Benzene, hydroxy-
Phthalic anhydride
1,2-benzenedicarboxylic acid anhydride
Selenium disulfide (r,t)
Sulfur selenide (r,t)
Tetrachloroethylene
Ethene,1,1,2,2-tetrachloro
Tetrahydrofuran (i)
Furan, tetrahydro- (i)
Toluene
Benzene, methyl-
1,1,1 -trichloroethane
Methylchloroform
Trichloroethylene
Trichloroethene
Xylene (i)
Benzene, dimethyl- (i,t)
A-6
-------
Appendix A. RCRA and Waste Form Codes Reported by Facilities in 1989 (continued)
Waste Form Codes
B001 Lab packs of old chemicals only
B101 Aqueous waste with low solvent
B102 Aqueous waste with low other toxic organics
B103 Spent acid with metals
B104 Spent acid without metals
B105 Acidic aqueous waste
B106 Caustic solution with metals but no cyanides
B107 Caustic solution with metals and cyanides
B108 Caustic solution with cyanides but no metals
B109 Spent caustic
B110 Caustic aqueous waste
B111 Aqueous waste with reactive sulfides
B112 Aqueous waste with other reactives (e.g., explosives)
B113 Other aqueous waste with high dissolved solids
B114 Other aqueous waste with low dissolved solids
B115 Scrubber water
B116 Leachate
B117 Waste liquid mercury
B119 Other inorganic liquids
B201 Concentrated solvent-water solution
B202 Halogenated (e.g., chlorinated) solvent
B203 Nonhalogenated solvent
B204 Halogenated/Nonhalogenated solvent mixture
B205 Oil-water emulsion or mixture
B206 Waste oil
B207 Concentrated aqueous solution of other organics
B208 Concentrated phenol ics
B209 Organic paint, ink, lacquer, or varnish
B210 Adhesive or epoxies
B211 Paint thinner or petroleum distillates
B219 Other organic liquids
B305 "Dry" lime or metal hydroxide solids chemically "fixed"
B306 "Dry" lime or metal hydroxide solids not "fixed"
B307 Metal scale, filings, or scrap
B308 Empty or crushed metal drums or containers
B309 Batteries or Battery parts, casings, cores
B310 Spent solid filters or adsorbents
B312 Metal-cyanides salts/chemicals
B313 Reactive cyanides salts/chemicals
B315 Other reactive salts/chemicals
A-7
-------
Appendix A. RCRA and Waste Form Codes Reported by Facilities in 1989 (continued)
Waste Form Codes (continued)
B316
B319
B501
B502
B504
B505
B506
B507
B508
B510
B511
B513
B515
B519
B601
B603
B604
B605
B607
B608
B609
Other metal salts/chemicals
Other waste inorganic solids
Lime sludge without metals
Lime sludge with metals/metal hydroxide- sludge
Other wastewater treatment sludge
Untreated plating sludge without cyanides
Untreated plating sludge with cyanides
Other sludges with cyanides
Sludge with reactive sulfides
Degreasing sludge with metal scale or filings
Air pollution control device sludge (e.g., fly ash, wet scrubber sludge)
Sediment or lagoon dragout contaminated with inorganics only
Asbestos slurry or sludge
Other inorganic sludges
Still bottoms of halogenated (e.g., chlorinated) solvents or other organic
liquids
Oily sludge
Organic paint or ink sludge
Reactive or polymerized organics
Biological treatment sludge
Sewage or other untreated biological sludge
Other organic sludges
A-8
-------
Appendix B. Initial Pollutants Included in Sampling Program
Conventional/Non-Conventional
Amenable Cyanide
Ammonia as N
BOD
COD
Total Cyanide
d-COD
Fluoride
Nitrate-nitrite as N
Oil + Grease
Dioxins/Furans
Octachlorodibenzo-p-dioxin
Octochlorodibenzo-furan
Total Heptachlorodibenzo-p-dioxin
Total Heptachlorodibenzofurans
Total Hexachlorodibenzo-p-dioxins
Total Hexachlorodibenzo-furans
Total Pentachlorodibenzo-p-dioxins
Total Pentachlorodibenzofurans
Total Tetrachlorodibenzo-p-dioxins
Total Tetrachlorodibenzo-furans
1,2,3,4,6,7,8-heptachloro-
benzo-p-dioxin
1,2,3,4,6,7,8-neptachloro-dibenzofuran
PH
Sulfide, Total
TOC
TOX
TSS
Hexavalent Chromium
Total Phenols
Total Phosphorus
1,2,3,4,7,8-hexachlorodibenzo-p-dioxin
1,2,3,4,7,8-hexachlorodibenzofuran
1,2,3,4,7,8,9-heptachlorodibenzofuran
1,2,3,6,7,8-hexachlorodibenzo-p-dioxin
1,2,3,6,7,8-heptachlordibenzofuran
1,2,3,7,8-pentachlorodibenzo-p-dioxin
1,2,3,7,8-pentachlorodibenzofuran
1,2,3,7,8,9-hexachlorodibenzo-p-dioxin
1,2,3,7,8,9-hexachlorodibenzofuran
2,3,4,6,7,8-hexachlorodibenzofuran
2,3,4,7,8-pentachlorodibenzofuran
2,3,7,8-tetrachlorodibenzo-p-dioxin
2,3,7,8-tetrachlorodibenzofuran
Alcohol/Formaldehydes
Ethanol
Formaldehyde
Methanol
Pentachlorophenol
Tetrachlorocatechol
Tetrachloroguaiacol
Trichlorosyringol
2-syringealdehyde
2,3,4,6-tetrachlorophenol
2,3,6-trichIorophenoI
2,4-dichlorophenol
2,4,5-trichlorophenol
2,4,6-trichlorophenol
2,6-dichlorophenol
3,4-dichlorophenol
3,4,5-trichlorocatechol
3,4,6-trichloroguaiacol
3,5-dichlorocatecol
3,5-dichlorophenol
3,6-dichlorocatechol
4-chlorophenol
4,5-dichlorocatechoI
4,5-dichloroguaiacol
4,5,6-trichloroguaiacol
4,6-dichloroguaiacol
5-chloroguaiacoI
5,6-dichlorovanilIin
6-chlorovanillin
B-1
-------
Appendix B. Initial Pollutants Included in Sampling Program (continued)
Metals
Aluminum
Antimony
Arsenic
Barium
Beryllium
Bismuth
Boron
Cadmium
Calcium
Cerium
Chromium
Cobalt
Copper
Dysprosium
Erbium
Europium
Gadolinium
Gallium
Germanium
Gold
Hafnium
Holmium
indium
Iodine
Indium
Iron
Lanthanum
Lead
Lithium
Lutetium
Magnesium
Manganese
Mercury
Molybdenum
Neodymium
Organics
Acenaphthene
Acenaphthylene
Acetophenone
Acrylonitrile
Nickel
Niobium
Osmium
Palladium
Phosphorus
Platinum
Potassium
Praseodymium
Rhenium
Rhodium
Ruthenium
Samarium
Scandium
Selenium
Silicon
Silver
Sodium
Strontium
Sulfur
Tantalum
Tellurium
Terbium
Thallium
Thorium
Thulium
Tin
Titanium
Tungsten
Uranium
Vanadium
Ytterbium
Yttrium
Zinc
Zirconium
Alpha-terpineol
Aniline
2,4,5-trimethylaniline
Anthracene
B-2
-------
Appendix B. Initial Pollutants Included in Sampling Program (continued)
Organics (continued)
Aramite
Benzanthrone
Benzene
Benzenethiol
Benzidine
Benzo(a)antracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(ghi)perylene
Benzo(k)fluoranthene
Benzoic Acid
Benzonitrile,3,5-dibromo-4-hydroxy
Benzyl Alcohol
Beta-naphthylamine
Biphenyl
Biphenyl,4-nitro
Bis(2-chloroethoxy)methane
Bis(2-chloroethyl)ether
Bis(2chloroisopropyl)ether
Bis(2-ethylhexyl)phthalate
Bromodichloromethane
Bromomethane
Butanone
Butyl Benzyl Phthalate
Carbazole
Carbon Disulfide
Chloroacetonitrile
Chlorobenzene
Chloroethane
Chloroform
Chloromethane
Chrysene
cis-1,3-dichloropropene
Crotonaldehyde
Crotoxyphos
Di-n-butyl Phthalate
Di-n-octyl Phthalate
Di-n-propylnitrosamine
Dibenzo(a, h)anthracene
Dibenzofuran
Dibenzothiophene
Dibromochloromethane
Dibromomethane
Diethyl Ether
Diethyl Phthalate
Dimethyl Phthalate
Dimethyl Sulfone
Diphenyl Ether
Diphenylamine
Diphenyldisulfide
Pentachloroethane
Ethyl Cyanide
Ethyl Emthacrylate
Ethyl Methanesulfonate
Ethyl Benzene
Ethylene Thiourea
Fluoranthene
Fluorene
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
Hexachloropropene
Hexanoic Acid
lndeno(1,2,3-cd)pyrene
lodomethane
Isobutyl Alcohol
Isophorone
Isosafrole
Longifolene
m-Xylene
Malachitegreen
Mestranol
Methapyrilene
Methyl Methacrylate
Methyl Methane Sulfonate
Methylene Chloride
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
n-Hexadecane
B-3
-------
Appendix B. Initial Pollutants Included in Sampling Program (continued)
Organics (continued)
n-Nitrosodi-n-butylamine
n-Nitrosodiethylamine
n-Nitrosodimethylamine
n-Nitrosodiphenylamine
n-Nitrosomethyiethylamine
n-Nitrosomethylphenylamine
n-Nitrosomorpholine
n-Nitrosopiperidine
n-Octacosane
n-Octadecane
n-Tetracosane
n-Tetradecane
n-Triacontane
n,n-Dimethylformamide
Naphthalene
Nitrobenzene
o+p-Xylene
o-Anisidine
o-Cresol
o-Toluidine
o-Toluidine,5-chloro-
p-Chloroaniline
p-Cresol
p-Cymene
p-Dimethylaminoazobenzo
p-Nitroaniline
Pentachlorobenzene
Pentachlorophenol
Pentamethylbenzene
Perylene
Phenacetin
Phenanthrene
Phenol
Phenol,2-methyl-4,6-dinitro
Phenol Thiazine
Pronamide
Pyrene
Pyridine
Resorcinol
Safrole
Squalene
Styrene
Tetrachloroethene
Tetrachloromethane
Thianaphthene
Thioacetamide
Thioxanthe-9-one
Toluene
Toluene,2,4-diamino
trans-1,2-dichloroethene
trans-1,3-dichloropropene
trans-1,4-dichloro-2-butene
Tribromomethane
Trichloroethene
Trichlorofluoromethane
Triphenylene
Tripropyleneglycol Methyl Ether
Vinyl Acetate
Vinyl Chloride
1 -Bromo-2-chlorobenzene
1 -Bromo-3-chlorobenzene
1-Chloro-3-nitrobenzene
1-Methyl Fluorene
1 -Methylphenanthrene
1-Naphthylamine
1-Phenyl Naphthalene
1,1-Dichloroethane
1,1-Dichloroethene
1,1,1 -Trichloroethane
1,1,1,2-Tetrachloroethane
1,1,2-Trichloroethane
1,1,2,2-Tetrachloroethane
1,2-Dibromo-3-chloropropane
1,2-Dibromoethane
1,2-Dichlorobenzene
1,2-Dichloroethane
1,2-Dichloropropane
1,2-Diphenyl Hydrazine
1,2,3-Trichlorobenzene
1,2,3-Trichloropropane
1,2,3-Trimethoxybenzene
1,2,4-Trichlorobenzene
B-4
-------
Appendix B. Initial Pollutants Included in Sampling Program (continued)
Organics (continued)
1,2,4,5-Tetrachlorobenzene
1,2:3,4-Diepoxybutane
1,3-Butadiene,2-chloro-
1,3-Dichloro-2-propanol
1,3-Dichlorobenzene
1,3-Dichloropropene
1,3,5-Trithiane
1,4-Dichlorobenzene
1,4-Dinitrobenzene
1,4-Dioxane
1,4-Naphthoquinone
1,5-Naphthalenediamine
2-(Methylthio)benzothiazole
2-Chloroethylvinyl Ether
2-Chloronaphthalene
2-Chlorophenol
2-Hexanone
2-lsopropylnaphthalene
2-Methylbenzothiozole
2-Methylnaphthalene
2-Nitroaniline
2-Nitrophenol
2-PhenylnaphthaIene
2-Picoline
2-Propanone
2-Propen-1-ol
2-Propenal
2-Propenenitrile,z-methyl-
2,3-Benzofluorene
2,3-Dichloroaniline
2,3-Dichloronitrobenzene
2,3,4,6-Tetrachlorophenol
2,3,6-TrichlorophenoI
2,4-Dichlorophenol
2,4-Dimethylphenol
2,4-Dinitrophenol
2,4-Dinitrotoluene
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
2,6-di-tert-butyl-p-benzoquinone
2,6-Dichloro-4-nitroaniline
2,6-Dichlorophenol
2,6-Dinitrotoluene
3-Chloropropene
3-Methylchlolanthrene
3-Nitroaniline
3,3'-Dichlorobenzidine
3,3'-Dimethoxybenzidine
3,6-Dimethylphenanthrene
4-Aminophenyl
4-Bromophenyl Phenyl Ether
4-Chloro-2-nitroaniline
4-Chloro-3-methylphenol
4-Chlorophenylphenyl Ether
4-Methyl-2-pentanone
4-Nitrophenol
4,4'-Methylenebis(2-chloroaniline)
4,5-Methyline Phenanthrene
5-Nitro-o-toluidine
7,12-Dimethyl Benz(a)anthracene
Pesticides/Herbicides
a-Chlordane
Acetic Acid(2,4-dichlorophenoxy)
Aldrin
Alpha-bhc
Azinphos-ethyl
Azinphos Methyl
Beta-bhc
Carbophenothion(trithion)
Chlorobenzilate
Chlorofenvinphos
Chorpyrifos
Coumaphos
Crotoxyphos-cgc/fpd
Dalapon
Delta-bhc
Demeton
Diallate
Diazinon
Dicamba
Dichlorofeuthion
B-5
-------
Appendix B. Initial Pollutants Included in Sampling Program (continued)
Pesticides/Herbicides
Dichlorprop
Dichlorvos
Dicrotophos(bidrin)
Dieldrin
Dimethoate
Dioxathion
Disulfoton
Endosultan Sulfate
Endosulfan-i
Endosulfan-ii
Endrin
Endrin Aldehyde
Endrin Ketone
Ethion
Ethoprop
Famphur
Fensulfothion
Funthion
G-chlordane
Heptachlor
Heptachlor Epoxide
Isodrin
Leptophos
Lindane(gamma-bhc)
Malathion
Mcpa
Mcpp
Merphos a
Merphos B (Def)
Methoxychlor
Methyl Chlorpyrifos
Methyl Parathion
Methyl Trithion
Mevinphos(phosdrin)
Mirex
Monocrotophos
Naled(dibrom)
Nitrofen(tok)
Parathion
PCB-1016
PCB-1221
PCB-1232
PCB-1242
PCB-1248
PCB-1254
PCB-1260
Pentachloronitrobenzene
Phorate
Phosmet
Phosphamidone
Phosphamidon Z
Ronnel
Santox(epn)
Sulprofos
Terbufos
Tetrachlorinphos
Tetraethyldithiopyrophosphate
Toxaphene
Trichloronate
Trifluralin(treflan)
2-Sec-butyl-4,6-dinitrophenol
2,4-DB
2,4,5-TrichlorophenoxyaceticAcid
2,4,5-TrichlorophenoxypropionicAcid
4,4'-DDD
4,4'-DDE
4,4'-DDT
Captafol
Captan
Kepone
Phosphamidon
Phosphoric Acid.trimethyl Ester
Phphoric Acid,tri-o-tolye Ester
Phosphoric Triamide.hexamethyl
TEPP
Trichlor Fon
1,4-Naphthoquinone,2,3-dichloro
Dithiocarbamate Anion
B-6
-------
APPENDIX C.
ACRONYMS AND DEFINITIONS
Administrator-"The Administrator of the U.S. Environmental Protection Agency.
Agency-The U.S. Environmental Protection Agency.
Average monthly discharge limitation - The highest allowable average of "daily
discharges" over a calendar month, calculated as the sum of all "daily discharges"
measured during the calendar month divided by the number of "daily discharges"
measured during the month.
BAT - The best available technology economically achievable, as described in Sec.
304(b)(2) oftheCWA.
BCT- The best conventional pollutant control technology, as described in Sec. 304(b)(4)
oftheCWA.
BOD5 - Biochemical oxygen demand - Five Day. A measure of biochemical decomposition
of organic matter in a water sample. It is determined by measuring the dissolved oxygen
consumed by microorganisms to oxidize the organic contaminants in a water sample under
standard laboratory conditions of five days and 70°C. BOD5 is not related to the oxygen
requirements in chemical combustion.
BPT - The best practicable control technology currently available, as described in Sec.
304(b)(1) oftheCWA.
Centralized waste treatment facility - Any facility that treats any hazardous or non-
hazardous industrial wastes received from off-site by tanker truck, trailer/roll-off bins,
drums, barge, or other forms of shipment. A "centralized waste treatment facility" includes
1) a facility that treats waste received from off-site exclusively and 2) a facility that treats
wastes generated on-site as well as waste received from off-site.
Centralized waste treatment wastewater - Water that comes in contact with wastes
received from off-site for treatment or recovery or that comes in contact with the area in
which the off-site wastes are received, stored or collected.
Clarifier-A. treatment unit designed to remove suspended materials from wastewater-
typically by sedimentation.
COD - Chemical oxygen demand. A bulk parameter that measures the oxygen-consuming
capacity of refractory organic and inorganic matter present in water or wastewater. COD
is expressed as the amount of oxygen consumed from a chemical oxidant in a specific test.
Commercial facility - Facilities that accept waste from off-site for treatment from facilities
not under the same ownership as their facility.
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APPENDIX C. ACRONYMS AND DEFINITIONS (continued)
Conventional pollutants-The pollutants identified in Sec. 304(a)(4) of the CWA and the
regulations thereunder (biochemical oxygen demand (BOD5), total suspended solids,
(TSS), oil and grease, fecal coliform, and pH).
CWA - Clean Water Act. The Federal Water Pollution Control Act Amendments of 1972
(33 U.S.C. 1251 et seq.), as amended, inter alia, by the Clean Water Act of 1977 (Public
Law 95-217) and the Water Quality Act of 1987 (Public Law 100-4).
CWT- Centralized Waste Treatment
Daily discharge - The discharge of a pollutant measured during any calendar day or any
24-hour period that reasonably represents a calendar day.
Direct discharger - A facility that discharges or may discharge treated or untreated
pollutants into waters of the United States.
Effluent - Wastewater discharges.
Effluent limitation - Any restriction, including schedules of compliance, established by a
State or the Administrator on quantities, rates, and concentrations of chemical, physical,
biological, and other constituents which are discharged from point sources into navigable
waters, the waters of the contiguous zone, or the ocean. (CWA Sections 301 (b) and
304(b).)
EPA - The U.S. Environmental Protection Agency.
Facility- A facility is all contiguous property owned, operated, leased or under the control
of the same person. The contiguous property may be divided by public or private right-of-
way.
Fuel Blending - The process of mixing organic waste for the purpose of generating a fuel
for reuse.
Indirect discharger- A facility that discharges or may discharge pollutants into a publicly-
owned treatment works.
LTA - Long-term average. For purposes of the effluent guidelines, average pollutant
levels achieved over a period of time by a facility, subcategory, or technology option.
LTAs were used in developing the limitations and standards in today's proposed
regulation.
Metal-bearing wastes - Wastes that contain metal pollutants from manufacturing or
processing facilities or other commercial operations. These wastes may include, but are
not limited to, the following: process wastewater, process residuals such as tank bottoms
or stills and process wastewater treatment residuals, such as treatment sludges.
New Source - "New source" is defined at 40 CFR 122.2 and 122.29.
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APPENDIX C. ACRONYMS AND DEFINITIONS (continued)
Non-commercial facility - Facilities that accept waste from off-site for treatment only from
facilities under the same ownership as their facility.
Non-conventional pollutants - Pollutants that are neither conventional pollutants nor
priority pollutants listed at 40 CFR Section 401.
NPDES - The National Pollutant Discharge Elimination System authorized under Sec. 402
of the CWA. NPDES requires permits for discharge of pollutants from any point source
into waters of the United States.
NSPS - New Source Performance Standards.
OCPSF - Organic Chemicals, Plastics, and Synthetic Fibers Manufacturing Effluent
Guideline.
Off-Site - "Off-site" means outside the boundaries of a facility.
Oily Wastes - Wastes that contain oil and grease from manufacturing or processing
facilities or other commercial operations. These wastes may include, but are not limited
to, the following: spent lubricants, cleaning fluids, process wastewater, process residuals
such as tank bottoms or stills and process wastewater treatment residuals, such as
treatment sludges.
On-site - "On-site" means within the boundaries of a facility.
Organic-bearing Wastes - Wastes that contain organic pollutants from manufacturing or
processing facilities or other commercial operations. These wastes may include, but are
not limited to, process wastewater, process residuals such as tank bottoms or stills and
process wastewater treatment residuals, such as treatment sludges.
Outfall - The mouth of conduit drains and other conduits from which a facility effluent
discharges into receiving waters.
Pipeline - "Pipeline" means an open or closed conduit used for the conveyance of
material. A pipeline includes a channel, pipe, tube, trench or ditch.
Point source category - A category of sources of water pollutants.
Pollutant (to water) - Dredged spoil, solid waste, incinerator residue, filter backwash,
sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, certain
radioactive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt, and
industrial, municipal, and agricultural waste discharged into water.
POTWorPOTWs - Publicly-owned treatment works, as defined at 40 CFR 403.3(0).
Pretreatment standard - A regulation that establishes industrial wastewater effluent quality
required for discharge to a POTW. (CWA Section 307(b).)
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APPENDIX C.
ACRONYMS AND DEFINITIONS (continued)
Priority pollutants - The pollutants designated by EPA as priority in 40 CFR Part 423
Appendix A.
Process wastewater- "Process wastewater" is defined at 40 CFR 122.2.
PSES - Pretreatment standards for existing sources of indirect discharges, under Sec.
307(b)oftheCWA.
PSNS - Pretreatment standards for new sources of indirect discharges, under Sec. 307(b)
and(c)oftheCWA.
RCRA - Resource Conservation and Recovery Act (PL 94-580) of 1976, as amended.
SIC- Standard Industrial Classification (SIC). A numerical categorization system used by
the U.S. Department of Commerce to catalogue economic activity. SIC codes refer to the
products, or group of products, produced or distributed, or to services rendered by an
operating establishment. SIC codes are used to group establishments by the economic
activities in which they are engaged. SIC codes often denote a facility's primary,
secondary, tertiary, etc. economic activities.
Solidification - The addition of agents to convert liquid or semi-liquid hazardous waste
to a solid before burial to reduce the leaching of the waste material and the possible
migration of the waste or its constituent from the facility. The process is usually
accompanied by stabilization.
Stabilization - A hazardous waste process that decreases the mobility of waste
constituents by means other than solidification. Stabilization techniques include mixing
the waste with sorbents such as fly ash to remove free liquids. For the purpose of this
rule, chemical precipitation is not a technique for stabilization.
TSS - Total Suspended Solids. A measure of the amount of particulate matter that is
suspended in a water sample. The measure is obtained by filtering a water sample of
known volume. The particulate material retained on the filter is then dried and weighed.
Variability factor-The daily variability factor is the ratio of the estimated 99th percentile
of the distribution of daily values divided by the expected value, median or mean, of the
distribution of the daily data. The monthly variability factor is the estimated 95th percentile
of the distribution of the monthly averages of the data divided by the expected value of the
monthly averages.
Waste Receipt - Wastes received for treatment or recovery.
Wafers of the United States - The same meaning set forth in 40 CFR 122.2.
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APPENDIX C.
ACRONYMS AND DEFINITIONS (continued)
Zero discharge - No discharge of pollutants to waters of the United States or to a POTW.
Also included in this definition are discharge of pollutants byway of evaporation, deep-well
injection, off-site transfer, and land application.
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