EPA REGION VII IRC
160189
United States
Environmental Protection
Agency
Office Of Water
(4303)
EPA821-R-95-021
April 1995
EPA Development Document For The
Proposed Effluent Limitations
Guidelines And Standards For
The Metal Products And
Machinery Phase 1
Point Source Category
cy
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United States
Environmental Protection
Agency
Office Of Water
(4303)
EPA821-R-95-021
April 1995
Development Document For The
Proposed Effluent Limitations
Guidelines and Standards For
The Metal Products And
Machinery Phase I
Point Source Category
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Development Document
For
The Proposed Effluent Limitations
Guidelines and Standards
For The
Metal Products And Machinery Phase I
Point Source Category
Carol M. Browner
Administrator
Robert Perciasepe
Assistant Administrator, Office of Water
Tudor T. Davies
Director, Office of Science and Technology
Thomas P. O'Farrell
Director, Engineering and Analysis Division
El wood H. Forsht
Chief, Chemicals and Metals Branch
William J. Cleary
Project Officer
April 1995
U.S. Environmental Protection Agency
Office of Water
Washington, DC 20460
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ACKNOWLEDGEMENTS
The Environmental Protection Agency appreciates the dedicated efforts, technical expertise,
and many contributions to the MP&M Phase I proposal rulemaking effort by the Radian
Corporation personnel in Herndon, Virginia under contract number 68-C4-0024.
The Agency acknowledges the plant managers, engineers, and other MP&M industry
representatives whose cooperation and assistance in site visitations and information gathering
activities greatly contributed to the completion of the technical studies and assessments.
A number of people within EPA made major contributions to this proposal rulemaking effort.
Mr. William deary (Project Officer, Metals Branch, Engineering and Analysis Division) was
instrumental in the management of the contractor efforts, coordination among many EPA
offices, and resolution of many complex issues. His deft guidance, technical expertise, and
tireless efforts were essential to the successful completion of this stage of the project. Jan
Goodwin (Energy Branch, Engineering and Analysis Division) also made significant
contributions to the technical efforts. Lynne Tudor and Helen Jacobs (Economic and
Statistical Analysis Branch, Engineering and Analysis Division) were major contributors to the
overall efforts through dedicated performance related to the economic analyses and the
statistical analyses, respectively. Dedicated administrative support was provided by Elizabeth
Smith of the Engineering and Analysis Division. Contributions were also made by Patrick
Bastek, Annette Huber, Sabita Rajvanshi, and Lisa Nelson, all of whom were previously
employed in the Engineering and Analysis Division.
Jocelyn Siegel (Pollution Prevention Division, Office of Prevention, Pesticides and Toxic
Substances) evaluated the pollution prevention aspects of the category. Ed Gardetto
(Exposure Assessment Branch, Standards and Applied Science Division) evaluated the
environmental benefits of the proposal. Legal support was provided by Karen Clark, Carrie
Wehling, and Susan Lepow of EPA's Office of General Council.
Additional contributions were made by the following members of the EPA MP&M
workgroup: Burnell Vincent, Bill Painter, Max Diaz, Paul Shapiro, Bryan Holtrop, Judi Kahl,
Paul Almodovar, Maria Malave, Nadine Steinberg, and John Sparks.
Finally, the MP&M proposal was developed with substantial input from the regional, state and
local permitting communities. In particular, Keith Silva and Greg Arthur of EPA's Region IX
office provided substantial input to the development of this proposal.
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TABLE OF CONTENTS
Page
1.0 SUMMARY AND CONCLUSIONS 1-1
1.1 Summary of the MP&M Phase I Point Source
Category 1-1
1.2 Proposed Effluent Limitations Guidelines and
Standards 1-3
2.0 LEGAL AUTHORITY 2-1
2.1 Regulatory Background 2-1
2.1.1 Clean Water Act 2-1
2.1.2 Section 304(m) Requirements 2-4
2.1.3 Pollution Prevention Act 2-5
2.2 Overview of Effluent Limitations Guidelines and
Standards for Metals Industries 2-6
2.3 Overview of the MP&M Point Source Category 2-7
3.0 APPLICABILITY 3-1
3.1 Applicability Of MP&M Phase I And Interface With
Phase II 3-1
3.2 Applicability Interfaces Between MP&M Phase I and
Previously Promulgated Metals Regulations 3-3
4.0 SUMMARY OF DATA COLLECTION ACTIVITIES 4-1
4.1 Mini Data Collection Portfolio 4-1
4.1.1 MDCP Recipient Selection and Mailing 4-1
4.1.2 Information Collected 4-2
4.1.3 MDCP Data Entry, Engineering Coding,
and Analysis 4-3
4.1.4 MDCP Mailout Results 4-3
4.1.5 Industry Scale-Up of MDCP Data 4-4
4.2 Data Collection Portfolio 4-4
4.2.1 DCP Recipient Selection and Mailing 4-5
4.2.2 Information Collected 4-6
4.2.3 DCP Review, Coding, and Data Entry 4-8
4.2.4 DCP Mailout Results 4-8
4.2.5 Industry Scale-Up of DCP Data 4-9
4.3 Site Visits 4-10
4.3.1 Criteria for Site Selection 4-10
4.3.2 Information Collected 4-11
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TABLE OF CONTENTS (Continued)
Page
4.4 Wastewater and Solid Waste Sampling 4-12
4.4.1 Criteria for Site Selection 4-13
4.4.2 Information Collected 4-13
4.4.3 Sample Collection and Analysis 4-14
4.5 Existing Data Sources 4-15
4.5.1 EPA/EAD Databases 4-15
4.5.2 Risk Reduction Engineering Laboratory
Treatability Database 4-16
4.5.3 Fate of Priority Pollutants in Publicly
Owned Treatment Works Database 4-16
4.5.4 The Domestic Sewage Study 4-17
4.5.5 Toxics Release Inventory Database 4-17
4.6 References 4-24
5.0 INDUSTRY DESCRIPTION 5-1
5.1 Number and Size of MP&M Phase I Sites . 5-1
5.2 Unit Operations Performed 5-2
5.3 Metal Types Processed 5-5
5.4 Water-Discharging MP&M Phase I Sites by Sector 5-6
5.5 Water-Discharging MP&M Phase I Sites and Total
Discharge Flow by Activity Combination 5-6
5.6 Water-Discharging MP&M Phase I Sites and Total
Discharge Flow by Discharge Status 5-8
5.7 Water-Discharging MP&M Phase I Sites by Total
Discharge Flow 5-8
5.8 Contract Hauling by MP&M Phase I Sites 5-9
5.9 MP&M Phase I Sites Not Discharging Process Water 5-9
5.10 MP&M Unit Operations and Rinses 5-11
5.11 Production-Normalizing Parameters and Production-
Normalized Flows 5-43
5.12 References 5-56
6.0 WASTEWATER CHARACTERISTICS 6-1
6.1 Wastewater Characteristics by Unit Operation 6-1
6.1.1 Hexavalent Chromium-Bearing Wastewaters 6-2
6.1.2 Cyanide-Bearing Wastewaters 6-4
6.1.3 Oil-Bearing Wastewaters 6-5
6.1.4 Chelated Metal-Bearing Wastewaters 6-6
11
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TABLE OF CONTENTS (Continued)
Page
6.1.5 Metal-Bearing Wastewaters 6-7
6.1.6 Qualitative Data from the MP&M DCPs for
Unidentified MP&M Unit Operations 6-8
6.2 Treatment Influent Characteristics 6-8
7.0 INDUSTRY SUBCATEGORIZATION 7-1
7.1 Factors Considered for Subcategorization 7-1
7.2 Unit Operations 7-2
7.3 Activity 7-2
7.4 Raw Materials 7-4
7.5 Products 7-5
7.6 Size of Site 7-6
7.6.1 Number of Employees 7-6
7.6.2 Wastewater Discharge Flow Rate 7-6
7.6.3 Production Rate 7-7
7.7 Geographical Location 7-7
7.8 Age 7-8
7.9 Total Energy Requirements 7-8
7.10 Air Pollution Control Methods 7-9
7.11 Solid Waste Generation and Disposal 7-9
7.12 Economic Impacts 7-9
8.0 SELECTION OF POLLUTANT PARAMETERS 8-1
8.1 Identification of Pollutant Parameters of Concern 8-2
8.2 Pass-Through Analysis for Indirect Dischargers 8-3
8.3 Pollutant Parameters Selected for Regulation 8-4
8.3.1 Priority and Nonconventional Organic
Pollutants 8-5
8.3.2 Priority Metal Pollutants 8-6
8.3.3 Nonconventional Metal Pollutants 8-6
8.4 References 8-20
9.0 SOURCE REDUCTION AND RECYCLING 9-1
9.1 Categories of Source Reduction and Recycling
Techniques 9-2
9.2 Source Reduction and Recycling Technologies Used in
the MP&M Industry 9-3
9.2.1 Metal-Shaping Operations 9-3
9.2.2 Surface Preparation and Treatment
Operations 9-4
in
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TABLE OF CONTENTS (Continued)
Page
9.2.3 Metal and Organic Deposition Operations 9-4
9.2.4 Assembly Operations 9-5
9.3 References 9-61
10.0 TECHNOLOGY OPTIONS 10-1
10.1 Technologies Considered 10-1
10.2 Technology Options 10-3
10.2.1 Option 1: End-of-Pipe Treatment 10-3
10.2.2 Option 2: End-of-Pipe Treatment and In-
Process Source Reduction and Recycling 10-5
10.2.3 Option 1A: Tiered Option for "Low" Flow
and "High" Flow Sites 10-6
10.2.4 Option 2A: End of Pipe Treatment and In-
Process Source Reduction and Recycling for
"High" Flow Sites (Preferred Option) 10-7
10.2.5 Option 3: Advanced End-of-Pipe Treatment
and Recycling 10-7
10.3 Technology Descriptions for In-Process Source
Reduction and Recycling Technologies 10-7
10.3.1 Centrifugation and Pasteurization of
Machining Coolants 10-8
10.3.2 Centrifugation and Recycling of Painting
Water Curtains 10-9
10.3.3 Countercurrent Cascade Rinsing 10-10
10.3.4 Electrolytic Recovery 10-11
10.3.5 Flow Reduction for Rinses and Baths 10-13
10.3.6 Ion Exchange (in-process) 10-16
10.3.7 Reverse Osmosis (both in-process and end-
of-pipe) 10-18
10.4 Technology Descriptions for Preliminary Treatment of
Segregated Wastewater Streams 10-20
10.4.1 Chemical Reduction of Chelated Metals 10-20
10.4.2 Chemical Reduction of Hexavalent
Chromium 10-22
10.4.3 Cyanide Destruction through Alkaline
Chlorination 10-23
10.4.4 Oil/Water Separation 10-24
IV
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TABLE OF CONTENTS (Continued)
Page
10.5 Technology descriptions for End-of-Pipe Treatment
Technologies 10-27
10.5.1 Chemical Precipitation and Sedimentation 10-28
10.5.2 Reverse Osmosis (End-of-Pipe) 10-31
10.5.3 Ion Exchange (end-of-pipe) 10-31
10.6 Technology Descriptions for Sludge Handling and
Disposal Technologies 10-31
10.6.1 Gravity Thickening 10-32
10.6.2 Pressure Filtration 10-32
10.6.3 Sludge Drying 10-33
10.6.4 Vacuum Filtration 10-33
10.7 References 10-70
11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND
VARIABILITY FACTORS 11-1
11.1 Sources of Technology Performance Data 11-1
11.2 Data Editing Procedures 11-2
11.2.1 Assessment of Treatment System
Performance 11-3
11.2.2 Identification of Process Upsets Occurring
During Sampling 11-4
11.2.3 Identification of Pollutants Not Present in
the Raw Wastewater at Sufficient
Concentrations to Evaluate Removal 11-5
11.2.4 Identification of Wastewater Treatment
Chemicals 11-6
11.3 Long-Term Average Concentrations and Variability
Factors 11-6
11.3.1 Modified Delta-Lognormal Model 11-7
11.3.2 Option Limitations and Long-Term Average 11-11
11.4 References 11-28
12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS 12-1
12.1 Summary of Costs 12-2
12.2 Model Site Development 12-2
12.2.1 Site Selection 12-3
12.2.2 Wastewater Stream Parameters 12-3
12.2.3 Pollutant Concentrations 12-5
12.2.4 Technology in Place 12-5
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TABLE OF CONTENTS (Continued)
Page
12.3 Methodology for Estimating Costs 12-6
12.3.1 Components of Cost 12-7
12.3.2 Sources and Standardization of Cost Data 12-8
12.3.3 Design and Cost Model 12-9
12.3.4 General Assumptions 12-12
12.4 Design and Costs of Individual Technologies 12-16
12.4.1 Flow Reduction for Rinses 12-17
12.4.2 Flow Reduction for Other Operations 12-18
12.4.3 Countercurrent Cascade Rinsing 12-18
12.4.4 Centrifugation and Pasteurization of
Machining Coolant 12-19
12.4.5 Centrifugation of Painting Water Curtains 12-20
12.4.6 In-Process Ion Exchange 12-20
12.4.7 Contract Hauling 12-22
12.4.8 Oil/Water Separation 12-23
12.4.9 Chemical Reduction of Hexavalent
Chromium 12-25
12.4.10 Cyanide Destruction 12-27
12.4.11 Chemical Reduction of Chelated Metals 12-28
12.4.12 Chemical Precipitation and Sedimentation 12-28
12.4.13 Sludge Thickening 12-30
12.4.14 Sludge Pressure Filtration 12-30
12.4.15 End-of-Pipe Ion Exchange 12-30
13.0 POLLUTANT LOADING AND REDUCTION ESTIMATES 13-1
13.1 Data Sources 13-3
13.1.1 Data Hierarchy 13-3
13.1.2 Use of Data for Nondetected Pollutants 13-4
13.2 Calculation of Unit Operation Production-Normalized
Pollutant Loadings 13-4
13.2.1 Production-Normalized Pollutant Loadings
for Each Unit Operation and Metal Type
Combination With Available Data 13-5
13.2.2 Production-Normalized Pollutant Loadings
Modelling Within Unit Operations 13-6
13.2.3 Production-Normalized Pollutant Loadings
Data Transfer Across Unit Operations 13-6
VI
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TABLE OF CONTENTS (Continued)
Page
13.3 Pollutant Loadings and Reductions 13-6
13.3.1 Calculation of Industry Raw Wastewater
Pollutant Loadings 13-7
13.2.2 Calculation of Industry Baseline Pollutant
Loadings 13-7
13.3.3 Calculation of Option-Specific Industry
Pollutant Loadings and Pollutant
Reductions 13-8
14.0 NONWATER QUALITY IMPACTS 14-1
14.1 Energy Requirements 14-1
14.2 Air Emissions Impacts 14-2
14.3 Solid Waste Generation 14-3
14.4 References 14-6
15.0 EFFLUENT LIMITATIONS AND STANDARDS 15-1
15.1 Technology Option 15-1
15.2 Numerical Limitations and Standards 15-2
15.3 Best Practicable Control Technology Currently
Available (BPT) 15-3
15.4 Best Conventional Pollutant Control Technology
(BCT) 15-5
15.5 Best Available Technology Economically Achievable
(BAT) 15-6
15.6 Pretreatment Standards for Existing Sources (PSES) 15-7
15.7 New Source Performance Standards (NSPS) and
Pretreatment Standards for New Sources (PSNS) 15-9
16.0 PERMITTING GUIDANCE 16-1
16.1 Implementing the MP&M Phase I Effluent Guidelines 16-2
16.1.1 Assessment of Water Use Practices 16-3
16.1.2 Use of Historical Flow in Developing Mass-
Based Limitations 16-3
16.1.3 Use of Flow Guidance in Developing Mass-
Based Limitations 16-4
16.2 Flow Guidance for Surface Treatment Rinsing
Operations 16-6
16.2.1 Identifying Sites With Pollution Prevention
and Water Conservation Practices 16-6
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TABLE OF CONTENTS (Continued)
Page
16.2.2 Flow Guidance for Calculating Mass-Based
Limitations 16-15
16.3 Flow Guidance for Machining Operations 16-21
16.3.1 Identifying Sites With Pollution Prevention
and Water Conservation Practices 16-22
16.3.2 Flow Guidance for Calculating Mass-Based
Limitations 16-28
16.4 Flow Guidance for Painting Operations 16-30
16.4.1 Identifying Sites With Pollution Prevention
and Water Conservation Practices 16-30
16.4.2 Flow Guidance for Calculating Mass-Based
Limitations 16-36
16.5 Flow Guidance for Cleaning Operations 16-38
16.5.1 Identifying Sites With Pollution Prevention
and Water Conservation Practices 16-39
16.5.2 Flow Guidance for Calculating Mass-Based
Limitations 16-45
16.6 References 16-74
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LIST OF TABLES
Page
1-1 MP&M Phase I Concentration-Based Limitations 1-4
3-1 Metal Products and Machinery (MP&M) Phase I Typical
Products 3-5
4-1 Metal Constituents Measured Under the MP&M Sampling
Program 4-19
4-2 Organic Constituents Measured Under the MP&M Sampling
Program 4-20
4-3 Additional Parameters Measured Under the MP&M
Sampling Program 4-23
5-1 Typical Unit Operations Performed at MP&M Sites 5-45
5-2 Additional Water-Using Unit Operations Performed at
MP&M Sites 5-46
5-3 Number of MP&M Phase I Sites Using and Discharging
Process Water by Unit Operation 5-47
5-4 MP&M Phase I Process Water Discharge Flow and Purpose
of Process Water by Unit Operation 5-51
6-1 Number of Samples Collected for MP&M Phase I Unit
Operations 6-10
6-2 Pollutant Parameters Identified in the MP&M Data
Collection Portfolios for Hexavalent Chromium-Bearing Unit
Operations and Associated Rinses 6-13
6-3 Pollutant Parameters Identified in the MP&M Data
Collection Portfolios for Cyanide-Bearing Unit Operations
and Associated Rinses 6-14
6-4 Analytical Data for Unit Operations Generating Oil-Bearing
Wastewater 6-15
IX
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LIST OF TABLES (Continued)
Page
6-5 Analytical Data for Rinses Generating Oil-Bearing
Wastewater 6-18
6-6 Pollutant Parameters Identified in the MP&M Data
Collection Portfolios for Oil-Bearing Unit Operations and
Associated Rinses 6-20
6-7 Pollutant Parameters Identified in the MP&M Data
Collection Portfolios for Chelated Metal-Bearing Unit
Operations and Associated Rinses 6-22
6-8 Analytical Data for Wastewater from Unit Operations
Generating Metal-Bearing Wastewater 6-23
6-9 Analytical Data for Wastewater from Rinses Generating
Metal-Bearing Wastewater 6-26
6-10 Pollutant Parameters Identified in the MP&M Data
Collection Portfolios for Metal-Bearing Unit Operations and
Associated Rinses 6-28
6-11 Pollutant Parameters Identified in the MP&M Data
Collection Portfolios for Unidentified Unit Operations 6-30
6-12 Analytical Data for Chemical Precipitation and
Sedimentation Influent 6-34
7-1 Metal Products and Machinery (MP&M) Sectors and Typical
Products 7-11
8-1 Priority Pollutant List 8-9
8-2 Pollutant Parameters Not Detected in Samples Collected
During the MP&M Sampling Program 8-10
8-3 Pollutant Parameters Detected in Less Than Three Samples
During the MP&M Sampling Program „ 8-12
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LIST OF TABLES (Continued)
Page
8-4 Pollutant Parameters Measured at Average Concentrations
Less Than 0.1 mg/L During the MP&M Sampling Program 8-13
8-5 Pollutant Parameters Selected for Further Consideration
Under MP&M Phase I 8-14
8-6 Summary of MP&M POTW Pass-Through Analysis 8-17
9-1 Typical Metal Products and Machinery Operations 9-6
9-2 Examples of Source Reduction and Recycling Technologies
or Metal-Shaping Operations 9-7
9-3 Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Surface Treatment 9-14
9-4 Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Solvent Cleaning 9-23
9-5 Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations 9-33
9-6 Examples of Source Reduction and Recycling Technologies
for Assembly Operations 9-58
10-1 MP&M Source Reduction Technologies 10-35
10-2 MP&M Recycling Technologies 10-40
10-3 MP&M End-of-Pipe Treatment and Disposal Technologies 10-42
11-1 MP&M Technology Effectiveness Data 11-13
11-2 Variability Factors and Long-Term Averages for Chemical
Precipitation and Sedimentation Treatment 11-22
11-3 Long-Term Averages and Limitations for Chemical
Precipitation and Sedimentation 11-26
XI
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LIST OF TABLES (Continued)
Page
12-1 MP&M Phase I Capital and Annual Costs 12-32
12-2 Summary of End-of-Pipe Technologies In Place at MP&M
Phase I Sites 12-33
12-3 MP&M Phase I Equipment Cost Equations 12-34
12-4 Components of Total Capital Investment 12-40
13-1 Summary of Pollutant Loadings by Option for MP&M
Phase I Direct Dischargers 13-9
13-2 Summary of Pollutant Loadings by Option for MP&M
Phase I Indirect Dischargers 13-13
13-3 Summary of Pollutant Reductions by Option for MP&M
Phase I Direct Dischargers 13-17
13-4 Summary of Pollutant Reductions by Option for MP&M
Phase I Indirect Dischargers 13-18
15-1 MP&M Phase I Concentration-Based Limitations 15-10
16-1 Descriptive Statistic of MP&M Data Collection Portfolio
Data 16-48
16-2 Water Conservation Methods for Surface Treatment Rinses 16-53
16-3 Definitions of Pollution Prevention and Water Conservation
Practices and Technologies 16-55
16-4 Factors Affecting Drag-Out 16-61
16-5 Rinse Water Required for Various Plating Processes Based
on Literature Values 16-62
16-6 Adjusted Production-Normalized Flow (PNF) Data for
Countercurrent Cascade Rinses MP&M Sampling Program 16-66
xn
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LIST OF TABLES (Continued)
Page
16-7 Pollution Prevention and Water Conservation Methods
Applicable to Machining Operations 16-67
16-8 Pollution Prevention and Water Conservation Methods
Applicable to Painting Operations 16-69
16-9 Pollution Prevention and Water Conservation Methods
Applicable to Cleaning Operations 16-70
xin
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LIST OF FIGURES
Page
10-1 End-of-Pipe Technology Trains for MP&M Technology
Options 1, 2, 1A, and 2A 10-51
10-2 In-Process Technology Trains for MP&M Technology
Options 1A, 2, 2A, and 3 10-52
10-3 End-of-Pipe Technology Train for MP&M Technology
Option 3 10-53
10-4 Centrifugation and Pasteurization of Machining Coolants 10-54
10-5 Centrifugation and Recycling of Painting Water Curtains 10-55
10-6 Countercurrent Cascade Rinsing 10-56
10-7 Electrolytic Recovery 10-57
10-8 Common Configurations for Application of Ion Exchange for
Chemical Recovery 10-58
10-9 In-Process Reverse Osmosis 10-59
10-10 Chemical Reduction of Chelated Metals 10-60
10-11 Chemical Reduction of Hexavalent Chromium 10-61
10-12 Cyanide Destruction through Alkaline Chlorination 10-62
10-13 Chemical Emulsion Breaking 10-63
10-14 Oil Skimming 10-64
10-15 Chemical Precipitation and Sedimentation 10-65
10-16 Effect of pH on Hydroxide Precipitation 10-66
10-17 Gravity Thickening 10-67
xiv
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LIST OF FIGURES (Continued)
Page
10-18 Pressure Filtration 10-68
10-19 Vacuum Filtration 10-69
11-1 Summary of Technology Performance Data Editing
Procedures 11-27
12-1 Relationship Among Options 12-41
12-2 Logic Used to Apply In-process Technologies and Practices 12-42
12-3 Logic Used to Apply End-of-Pipe Technologies and Practices 12-43
13-1 Estimation of MP&M Pollutant Loadings and Reductions 13-19
16-1 MP&M Phase I Permitting Process Flow Chart 16-71
16-2 Examples of Rinsing Configurations with Increasing Levels of
Good Water Use Practices 16-72
xv
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1.0 SUMMARY AND CONCLUSIONS
1.0 SUMMARY AND CONCLUSIONS
Pursuant to the Clean Water Act, EPA is proposing effluent limitations guidelines and
standards for the Metal Products and Machinery (MP&M) Phase I Point Source
Category. This document and the administrative record for this rulemaking provide the
technical basis for these effluent limitations guidelines for new and existing direct
dischargers, and pretreatment standards for new and existing indirect dischargers. Direct
dischargers are sites that discharge wastewater to a surface water. Indirect dischargers
are sites that discharge wastewater to a publicly-owned treatment works (POTW).
Section 1.1 presents a summary of the MP&M Phase I industry. Section 1.2 summarizes
the proposed effluent limitations guidelines and standards.
1.1 Summary of the MP&M Phase I Point Source Category
The MP&M Phase I Point Source Category applies to sites engaged in manufacturing,
rebuilding, or maintaining finished metal parts, products, or machines within the
following seven industrial sectors:
• Aerospace;
• Aircraft;
• Electronic Equipment;
• Hardware;
• Mobile Industrial Equipment;
• Ordnance; and
• Stationary Industrial Equipment.
The MP&M Phase I category includes an estimated 79,613 sites. Of these, an estimated
10,601 sites discharge process water. The majority of the sites that do not discharge
water are sites which employ unit operations that do not generate process wastewater.
Of the 10,601 wastewater-discharging sites, an estimated 1,797 are direct dischargers,
8,440 are indirect dischargers, and 364 are both direct and indirect dischargers.
MP&M sites perform a wide variety of process unit operations on metal parts. In
general, MP&M unit operations can be characterized as belonging to one or more of the
following types of unit operations:
• Metal shaping operations;
• Surface preparation operations;
• Organic deposition operations;
• Surface finishing operations; and
• Assembly operations.
At a given MP&M site, the specific unit operations performed and the sequence of
operations depend on many factors, including the activity (i.e., manufacturing, rebuilding,
1-1
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1.0 SUMMARY AND CONCLUSIONS
or maintenance), industrial sector, and type of product processed. Depending on these
factors, MP&M sites perform many different combinations and sequences of unit
operations. Process water is used for and discharged from many of the MP&M unit
operations. For some operations, process water may or may not be used, depending on
the purpose of the operation, raw materials, and final product use.
EPA estimates that MP&M Phase I sites discharge approximately 23.2 billion gallons of
process wastewater per year. These wastewaters typically contain metal pollutants (e.g.,
aluminum, cadmium, copper, chromium, iron, nickel, zinc) and total suspended solids.
Many of the MP&M wastewaters also contain oil and grease, cyanide, hexavalent
chromium, and organic pollutants. The following table summarizes the amount of
pollutants estimated by EPA to have been discharged from MP&M Phase I sites in 1989.
Estimated Amount of Pollutants Discharged from MP&M Phase I Sites in 1989
Pollutant
Metal Pollutants
Organic Pollutants
Cyanide
Total Suspended Solids
Oil and Grease
Million Pounds Discharged in
13
2.5
0.17
20
190
1989
Source: EPA MP&M pollutant loading estimates.
EPA identified several in-process pollution prevention and recycling and end-of-pipe
treatment technologies and practices to control the discharge of pollutants from MP&M
Phase I sites. These technologies and practices are summarized in the following table.
In-Process Pollution Prevention and Recycling
and End-of-Pipe Treatment Technologies and Practices
In-Process Technologies and Practices
End-Of-Pipe Technologies and Practices
Flow reduction for rinses
Flow reduction for other operations (e.g., alkaline and
acid treatment baths, machining coolants)
Countercurrent cascade rinsing
Centrifugation and pasteurization of machining coolants
Centrifugation of painting water curtains
In-process ion exchange and electrolytic recovery
Oil/water separation
Chemical reduction of hexavalent chromium
Cyanide destruction
Chemical reduction of chelated metals
Contract hauling of solvent degreasing
wastewaters for off-site treatment
Chemical precipitation and sedimentation
Sludge thickening
Sludge pressure filtration
End-of-pipe ion exchange
Source: MP&M DCPs, MP&M site visits, technical literature.
1-2
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1.0 SUMMARY AND CONCLUSIONS
These technologies were combined into several different technology options considered
by EPA for the different levels of regulatory control required by the Clean Water Act.
Engineering costs were estimated for each of the technology options for a set of
statistically-selected model sites. These model site costs were then statistically scaled to
the MP&M Phase I category. EPA also estimated pollutant loadings and removals
associated with each of the technology options. The costs, loadings, and removals were
used to assess the cost-effectiveness of each technology option. EPA also used the costs
to estimate the economic and financial impact on the industry of implementing the
various options, including the number of potential site closures, the number of potential
job losses and gains, and the ability of the site to finance the pollution controls.
1.2 Proposed Effluent Limitations Guidelines and Standards
Based on consideration of the factors discussed above, EPA developed the proposed
MP&M Phase I effluent limitations guidelines and standards. The proposed effluent
limitations guidelines and standards consist of mass-based limitations for all direct
dischargers, for all new indirect dischargers, and for all indirect dischargers with greater
than or equal to one million gallons per year of process wastewater discharge. Existing
indirect dischargers with less than one million gallons per year of process wastewater
discharge are exempt from the proposed regulation.
For all sites regulated under MP&M Phase I, permit writers will be required to convert
the proposed concentration-based limitations to mass-based limitations using the flow
guidance provided in Section 16.0. These proposed concentration-based limitations were
developed based on chemical precipitation and sedimentation, used in conjunction with
flow reduction, pollution prevention, and preliminary treatment technologies. However,
these technologies are not mandated under the proposed effluent guidelines and
pretreatment standards. Sites regulated under the proposed effluent limitations and
pretreatment standards are required to meet the discharge limitations but are not
required to use the technologies on which the limitations are based.
Table 1-1 presents the proposed concentration-based limitations. The technology basis
described above was used to develop the limitations for all regulatory levels of control;
therefore, the concentrations are the same for each level of control. The proposed rule
would require that permit writers convert these limitations to mass-based limitations.
EPA recommends that, for sites with good pollution prevention and water conservation
technologies in place that are equivalent to those listed above, permit writers use
historical flow as a basis for converting the concentration-based limitations to mass-
based. For sites without these types of technologies in place, EPA recommends that
permit writers do not use historical flow, but use other tools listed in Section 16.0.
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1.0 SUMMARY AND CONCLUSIONS
Table 1-1
MP&M Phase I Concentration-Based Limitations
Pollutant or
Pollutant Parameter
Aluminum (T)(i)
Cadmium (T)(i)
Chromium (T)(l)
Copper (T)(i)
Iron (T)(i)
Nickel (T)(i)
Zinc (T)(i)
Cyanide (T)(i)
Oil and Grease (2)
Total Suspended Solids (3)
pH
Maximum For Any
One Day
(milligrams/liter)
1.4
0.7
0.3
1.3
2.4
1.1
0.8
0.03
35
73
(4)
Monthly Average -
Shall Not Exceed
(milligrams/liter)
1.0
0.3
0.2
0.6
1.3
0.5
0.4
0.02
17
36
(4)
Source: MP&M Technology Effectiveness Concentration (TEC) database.
(1) These concentrations apply to BPT, BAT, PSES, NSPS, and PSNS.
(2) These concentrations apply to all levels of regulatory control. Oil and grease is proposed as an
indicator for organic pollutants.
(3) These concentrations apply to BPT, BCT, and NSPS.
(4) Within 6.0 to 9.0 standard units. This applies to BPT, BCT, and NSPS
(T) Total (e.g., total aluminum, total cadmium, total cyanide).
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2.0 LEGAL AUTHORITY
This regulation is being proposed under the authority of Sections 301, 304, 306, 307, 308,
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."
2.1 Regulatory Background
2.1.1 Clean Water Act
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
required to issue effluent limitations guidelines, pretreatment standards, and new source
performance standards for industrial dischargers. These guidelines and standards are
summarized briefly below.
1. Best Practicable Control Technology Currently Available (BPT)
(Section 304(b)(l) of the Act).
BPT effluent limitations guidelines are applicable to direct
discharging sites (i.e., sites that discharge wastewater to surface
water). BPT effluent limitations guidelines are generally based on
the average of the best existing performance by sites of various
sizes, ages, and unit processes within the category or subcategory for
control of pollutants.
In establishing BPT effluent limitations guidelines, EPA considers
the total cost of achieving effluent pollutant reductions in relation to
the effluent pollutant reduction benefits, the age of equipment and
facilities involved, the processes used, process changes required,
engineering aspects of the control technologies, nonwater quality
environmental impacts, and other factors as the EPA Administrator
deems appropriate. The Agency considers the category- or
subcategory-wide cost of applying the technology in relation to the
effluent pollutant reduction benefits. Where existing performance is
uniformly inadequate, BPT may be transferred from a different
subcategory or category.
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2. Best Available Technology Economically Achievable (BAT)
(Sections 304(b)(2)(B) and 307(a)(2) of the Act).
BAT effluent limitations guidelines are applicable to direct
discharging sites. In general, BAT effluent limitations guidelines
represent the best existing economically achievable performance of
sites in the industrial subcategory or category. The Act establishes
BAT as the principal national means of controlling the direct
discharge of priority pollutants and nonconventional pollutants to
waters of the United States. The factors considered in assessing
BAT include the age of equipment and sites involved, the processes
used, potential process changes, and nonwater quality environmental
impacts. The Agency retains considerable discretion in assigning the
weight to be accorded these factors. As with BPT, where existing
performance is uniformly inadequate, BAT may be transferred from
a different subcategory or category. BAT may include process
changes or internal controls, even when these technologies are not
common industry practice. BPT and BAT effluent limitations
guidelines are typically established in a tiered approach, such that
sites must first comply with BPT, which is then superseded by BAT
after an established period of time.
3. Best Conventional Pollutant Control Technology (BCT)
(Sections 301(b)(2)(E) and 304(a)(4) of the Act).
The 1977 Act included Section 301(b)(2)(E), which established BCT
for discharges of conventional pollutants from existing industrial
point sources. BCT effluent limitations guidelines are applicable to
direct discharging sites. Section 304(a)(4) designated the following
as conventional pollutants: biochemical oxygen demand (BOD),
total suspended solids (TSS), fecal coliform, 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. BPT and BCT effluent
limitations guidelines are typically established in a tiered approach,
such that sites must first comply with BPT, which is then superseded
by BCT after an established period of time.
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-reasonableness" test [American Paper Institute v. EPA,
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660 F.2d 954 (4th Or. 1981)]. EPA must find that proposed BCT
limitations are "reasonable" under both parts of the test before
establishing them as BCT. If the candidate BCT technology does
not pass both parts of the test, BCT is established equal to BPT.
Otherwise, BCT supersedes BPT. In no case may BCT be less
stringent than BPT. EPA's methodology for the development of
BCT limitations was issued in 1986 (51 FR 24974, July 9, 1986).
4. New Source Performance Standards (NSPS)
(Section 306 of the Act).
NSPS are applicable to direct discharging sites and are based on the
best available demonstrated treatment technology. New sites 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 numerical values attainable
through the application of the best available control technology for
all pollutants (i.e., conventional, nonconventional, and priority
pollutants). In establishing NSPS, EPA is directed to take into
consideration the cost of achieving the effluent pollutant reduction
and any nonwater quality environmental impacts.
5. Pretreatment Standards for Existing Sources (PSES)
(Section 307(b) of the Act).
PSES are applicable to indirect discharging sites (i.e., sites that
discharge to a publicly-owned treatment works (POTW)). The Act
requires PSES for pollutants that pass through POTWs or interfere
with POTWs' treatment processes or sludge disposal methods. The
1977 Act indicates that pretreatment standards are to be technology-
based and analogous to the BAT effluent limitations guidelines for
removal of priority and nonconventional pollutants. For the purpose
of determining whether to promulgate national category-wide
pretreatment standards, EPA generally determines if there is pass-
through of a pollutant and thus a need for categorical standards. If
the nation-wide average percent of a pollutant removed by well-
operated POTWs achieving secondary treatment is less than the
percent removed by the BAT model treatment system, then the
pollutant is said to pass through the POTWs.
The General Pretreatment Regulations, which set forth the
framework for the implementation of categorical pretreatment
standards, are found at 40 CFR Part 403. The regulations contain a
definition of pass-through that addresses local rather than national
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instances of pass-through and does not use the percent removal
comparison test described above (52 FR 1586, January 14, 1987).
6. Pretreatment Standards for New Sources (PSNS) (Section 307(b) of
the Act).
PSNS are applicable to indirect discharging sites. 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, like new direct dischargers, have
the opportunity to incorporate into their sites the best available
demonstrated technologies. The Agency considers the same factors
in promulgating PSNS that it considers in promulgating NSPS.
The following table summarizes these regulatory levels of control.
Summary of Regulatory Levels of Control
Type of Sites Regulated
Existing Direct Dischargers
New Direct Dischargers
Existing Indirect Dischargers
New Indirect Dischargers
Pollutants Regulated
Priority Pollutants
Nonconventional Pollutants
Conventional Pollutants
BPT
X
BPT
X
X
X
BAT(a)
X
BAT(a)
X
X
BCT*"
X
BCT*"
X
NSPS
X
NSPS
X
X
X
PSES
X
PSES
X
X
PSNS
X
PSNS
X
X
Source: Clean Water Act
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Manufacturing and Rebuilding) Point Source Category as requiring effluent guidelines,
and identified an estimated schedule for regulatory action.
The 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 terms of the Consent
Decree are reflected in the Effluent Guidelines Plan published on September 8, 1992
(57 FR 41000). As a result of this decree, EPA established a plan to propose effluent
guidelines for the Metal Products and Machinery (MP&M) Phase I Point Source
Category by November 1994, and take final action by May 1996. EPA filed a motion
with the court on September 28, 1994, and was granted an extension until March 31,
1995, for the EPA Administrator to sign the proposed regulation and a subsequent four-
month extension for signature of the final regulation in September 1996.
2.1.3 Pollution Prevention Act
In the Pollution Prevention Act of 1990 (PPA) (42 U.S.C. 13101 et seq., Pub.L. 101-508,
November 5, 1990), Congress declared pollution prevention the national policy of the
United States. This act declares that pollution "should be prevented or reduced
whenever feasible; pollution that cannot be prevented should be recycled or reused in an
environmentally safe manner whenever feasible; pollution that cannot be recycled should
be treated in an environmentally safe manner whenever feasible; and disposal or release
into the environment should be employed only as a last resort..." (Sec. 6602; 42 U.S.C.
13103).
According to the PPA, source reduction reduces the generation and release of hazardous
substances, pollutants, wastes, contaminants or residuals at the source, usually within a
process. The term source reduction "includes equipment or technology modifications,
process or procedure modifications, reformation or redesign of products, substitution of
raw materials, and improvements in housekeeping, maintenance, training, or inventory
control. The term 'source reduction' does not include any practice which alters the
physical, chemical, or biological characteristics or the volume of a hazardous substance,
pollutant, or contaminant through a process or activity which itself is not integral to or
necessary for the production of a product or the providing of a service." In effect, source
reduction means reducing the amount of a pollutant that enters a waste stream or that is
otherwise released into the environment prior to out-of-process recycling, treatment, or
disposal.
The PPA directs the Agency to, among other things, "review regulations of the Agency
prior and subsequent to their proposal to determine their effect on source reduction"
(Sec. 6604; 42 U.S.C. 13103). This directive led the Agency to implement a pilot project
called the Source Reduction Review Project (SRRP). The SRRP facilitates the
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integration of source reduction in the Agency's regulations, including the technology-
based effluent guidelines.
2.2
Overview of Effluent Limitations Guidelines and Standards for Metals
Industries
EPA has promulgated effluent limitations guidelines and standards for 13 metals
industries. These regulations cover metal manufacturing, metal forming, and component
finishing, as summarized below.
Summary of Metals Industry Effluent Guidelines
Coverage Area
Title
CFR Reference
Metal and Metal Alloy
Manufacturing
Iron and Steel Manufacturing'"'
Nonferrous Metals Manufacturing
Ferroalloy Manufacturing
40 CFR 420
40 CFR 421
40 CFR 424
Metal Forming
Iron and Steel Manufacturing'"1
Metal Molding and Casting
Aluminum Forming
Copper Forming
Nonferrous Metals Forming and Metal Powders
40 CFR 420
40 CFR 464
40 CFR 467
40 CFR 468
40 CFR 471
Component Finishing
Electroplating
Iron and Steel Manufacturing60
Metal Finishing
Battery Manufacturing
Coil Coating
Porcelain Enameling
Electrical and Electronic Component
Manufacturing
40 CFR 413
40 CFR 420
40 CFR 433
40 CFR 461
40 CFR 465
40 CFR 466
40 CFR 469
Source: Code of Federal Regulations, Part 40
(a)The Iron and Steel Manufacturing category includes metal manufacturing, metal forming, and component
finishing.
In 1986, the Agency reviewed the coverage of these regulations and identified a
significant number of wastewater-discharging metal processing sites that were not
covered by these 13 regulations. Based on the results of this review, EPA performed a
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detailed analysis of these unregulated sites. This analysis resulted in the development of
the Machinery Manufacturing and Rebuilding (MM&R) Point Source Category. In 1989,
the Agency published a Preliminary Data Summary (PDS) for the MM&R industry,
which is included in the record for this rulemaking. Based on information contained in
the PDS, the MM&R category was divided into two phases and was included in EPA's
January 2, 1990 Effluent Guidelines Plan (55 FR 80). On May 7, 1992, EPA changed
the category name to Metal Products and Machinery (MP&M) to clarify the coverage of
the category (57 FR 19748); questionnaire respondents found the MM&R label
confusing and interpreted the category to apply only to machinery sites. The Agency
believes that the MP&M title better describes the coverage of the category.
2.3
Overview of the MP&M Point Source Category
The MP&M Point Source Category covers facilities that generate wastewater while
processing metal parts, metal products, and machinery, and includes operations
performed during manufacturing, assembly, rebuilding, repair, and maintenance. The
category encompasses two regulatory phases and 15 industrial sectors, as summarized
below.
Sector Coverage of MP&M Phases
Phase I
Phase II
Aerospace
Aircraft
Electronic Equipment
Hardware
Mobile Industrial Equipment
Ordnance
Stationary Industrial Equipment
Bus and Truck
Household Equipment
Instruments
Motor Vehicles
Office Machines
Precious and Nonprecious Metals
Railroad
Ships and Boats
A site is considered to be included in a sector if any of the products processed at the site
are used within that sector. For example, a site manufacturing aircraft components
would be included in the aircraft sector, while a site manufacturing bolts that are used in
aircraft and stationary pumps would be included in both the aircraft and the stationary
industrial equipment sectors. The regulatory coverage of the phases and sectors are
further described in Section 3.0.
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The sectors included in each phase were selected based on an analysis similar to that
used to set overall priorities for the development of new and revised guidelines under
Section 304(m) of the Clean Water Act. The analysis focused on the amounts and kinds
of wastewater discharges created by the different sectors and the likely economic impacts
of effluent limitations guidelines and standards. This analysis is discussed in EPA's
Effluent Guidelines Plan (55 FR 80), which is included in the record for this rulemaking.
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3.0 APPLICABILITY
3.0
APPLICABILITY
The Metal Products and Machinery (MP&M) Point Source Category (including both
Phase I and II) applies to industrial sites engaged in manufacturing, rebuilding, or
maintaining finished metal parts, products, or machines within fifteen industrial sectors.
Sites within these sectors manufacture, maintain, and rebuild products under more than
190 different Standard Industrial Classification (SIC) codes.
In developing the MP&M effluent guidelines, EPA divided the category into two phases.
The MP&M Phase I effluent guidelines apply to process wastewater discharges from sites
performing manufacturing, rebuilding or maintenance on a metal part, product or
machine to be used in one of seven industrial sectors, while MP&M Phase II applies to
wastewater discharges from eight additional sectors. These sectors are summarized in
the following table.
MP&M Industrial Sectors
MP&M Phase I Sectors
MP&M Phase II Sectors
Aerospace
Aircraft
Electronic Equipment
Hardware
Mobile Industrial Equipment
Ordnance
Stationary Industrial Equipment
Bus and Truck
Household Equipment
Instruments
Motor Vehicle
Office Machine
Precious and Nonprecious Metals
Railroad
Ships and Boats
Table 3-1 (located at the end of this section) lists typical products manufactured within
MP&M Phase I. This is not an exhaustive list, but is presented to provide general
guidance as to the types of products within this phase. MP&M Phase II is scheduled for
promulgation approximately three years after Phase I.
Section 3.1 presents additional discussion on the applicability of MP&M Phase I,
including a discussion of the interface between Phase I and Phase II. Section 3.2
presents a discussion of the regulatory interface between MP&M Phase I and existing
metals industry regulations.
3.1
Applicability Of MP&M Phase I And Interface With Phase II
As discussed above, the MP&M Phase I effluent guidelines apply to process wastewater
discharges from sites performing manufacturing, rebuilding, or maintenance on a metal
part, product, or machine to be used in one of the seven Phase I industrial sectors. EPA
expects that some products will clearly fit within certain industrial sectors while others
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3.0 APPLICABILITY
will be more difficult to define. Some examples of how the MP&M Phase I regulation
would apply are provided below for clarification.
An example of a site clearly engaged in Phase I is a site that manufactures aircraft
engines. The site would be considered in the aircraft industrial sector of MP&M. Since
the aircraft sector is in MP&M Phase I, the aircraft engine manufacturer would be
covered by MP&M Phase I.
An example of a site clearly engaged in Phase II is a site that manufactures school buses.
The site would be considered in the bus and truck industrial sector of MP&M. Since the
bus and truck industrial sector is in MP&M Phase II, the school bus manufacturer would
be covered by MP&M Phase II.
An example of a site engaged in more than one MP&M Phase I industrial sector is a site
that manufacturers farm tractors and farm conveyors. The site would be considered in
the mobile industrial equipment and the stationary industrial equipment sectors. Since
both mobile industrial equipment and stationary industrial equipment are MP&M
Phase I industrial sectors, the farm tractor and farm conveyor manufacturer would be
covered by MP&M Phase I.
An example of a site that could be difficult to assign to a specific MP&M industrial
sector would be a car door handle manufacturing site. If a car door handle were
considered a piece of hardware, then the site would be covered under MP&M Phase I
(hardware industrial sector). If the door handle were considered a motor vehicle part,
then the site would be covered under MP&M Phase II (motor vehicle industrial sector).
In cases where products could be viewed under different industrial sectors, the industrial
sector(s) which most accurately matches the market into which the product is sold should
be assigned. In addition, if a metal part has a specific use in one of the fifteen MP&M
industrial sectors, then the sector in which it is intended to be used is the industrial
sector that should be assigned to that site. In this example, the car door handle has no
uses other than operating the door of a car, and this site would be considered in the
motor vehicle industrial sector (MP&M Phase II).
Another example of a site that could be difficult to assign to a specific MP&M industrial
sector would be a site that manufactures pistons for use in internal combustion engines,
stationary generators, automotive engines, aircraft engines, and truck engines. Since the
pistons are used in a wide variety of industrial applications and are not produced for use
in a specific MP&M industry, the piston manufacture should be considered to be making
a fabricated metal product and be covered under MP&M Phase I (hardware).
Some MP&M sites have operations in both MP&M Phase I and Phase II industrial
sectors. The MP&M Phase I effluent guidelines apply to combined wastewater
discharges when a site is manufacturing, rebuilding, or maintaining finished metal
products in both Phase I and Phase II sectors (i.e., MP&M Phase I covers wastewater
discharges from all sites performing any operations in a Phase I industrial sector). EPA's
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3.0 APPLICABILITY
data collection and analysis of MP&M sites included MP&M Phase I and Phase II
overlap sites. Many of these sites use the same equipment to manufacture, rebuild, and
maintain goods for both Phase I and Phase II sectors, making it impossible to separate
wastewater generated by operations performed in the two phases. EPA believes that
regulating combined Phase I and Phase II wastewater discharges under Phase I will
alleviate burdens on the permit writers and allow sites to achieve compliance more cost
effectively, since they typically will have to comply with one set of limits.
An example of a site that is in MP&M Phase I and Phase II industrial sectors would be
a site which manufactures hand tools and household cooking equipment. The site would
be considered in the hardware and household equipment sectors. Since the hardware
industrial sector is in MP&M Phase I and the household equipment industrial sector is in
MP&M Phase II, the site has operations in both MP&M phases. The MP&M Phase I
effluent guidelines apply to combined wastewater discharges from sites with operations in
both MP&M Phase I and Phase II. As a result, if the site combined its process
wastewater prior to discharge, all of the site's process wastewater (including wastewater
generated in manufacturing cooking equipment) would be regulated under MP&M
Phase I. If the site segregated the wastewater generated from Phase I operations from
the wastewater generated from Phase II operations, the Phase I wastewater would be
regulated under Phase I, while the Phase II wastewater would be regulated under
Phase II.
3.2 Applicability Interfaces Between MP&M Phase I and Previously
Promulgated Metals Regulations
EPA has previously established effluent limitations guidelines and standards for thirteen
industries which may perform unit operations or process parts that are sometimes found
in MP&M Phase I sites. These effluent guidelines are:
Electroplating (40 CFR Part 413);
Iron & Steel Manufacturing (40 CFR Part 420);
Nonferrous Metals Manufacturing (40 CFR Part 421);
Ferroalloy Manufacturing (40 CFR Part 424);
Metal Finishing (40 CFR Part 433);
Battery Manufacturing (40 CFR Part 461);
Metal Molding & Casting (40 CFR Part 464);
Coil Coating (40 CFR Part 465);
Porcelain Enameling (40 CFR Part 466);
Aluminum Forming (40 CFR Part 467);
Copper Forming (40 CFR Part 468);
Electrical & Electronic Components (40 CFR Part 469); and
Nonferrous Metals Forming & Metal Powders (40 CFR Part 471).
With the exception of Electroplating and Metal Finishing, these existing effluent
guidelines generally apply to the production of semi-finished products, while the MP&M
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3.0 APPLICABILITY
Phase I effluent guidelines apply to finished metal parts, products, and machines. EPA
recognizes that unit operations performed in industries covered by the existing effluent
guidelines generate wastewater similar to wastewater generated by unit operations
performed at MP&M Phase I sites. Many MP&M sites also have operations covered by
one or more of the existing metal processing effluent guidelines. In general, with the
exception of the Metal Finishing effluent guidelines, the existing metals industry effluent
guidelines will continue to apply to operations judged to be covered by those effluent
guidelines. The MP&M Phase I effluent guidelines cover unit operations that, at
present, are not covered by an existing metals regulation, that are covered by the Metal
Finishing effluent guidelines, or that are covered by best professional judgment. The
MP&M Phase I effluent guidelines replace the Metal Finishing effluent guidelines for
sites within an MP&M Phase I industrial sector, if the sites are direct dischargers or
indirect dischargers with greater than or equal to one million gallons of annual process
wastewater discharge. MP&M Phase I does not apply to surface finishing job shops,
independent circuit board manufacturers, or indirect dischargers with less than one
million gallons of annual process wastewater discharge; these will continue to be covered
by Electroplating and Metal Finishing, where appropriate.
Both MP&M Phase I and Metal Finishing apply to the same types of unit operations.
EPA has included sites covered by Metal Finishing in the data collection and study of
the MP&M Phase I industry and has estimated the costs and impacts on these sites to
comply with the proposed MP&M Phase I regulation. EPA anticipates that the MP&M
Phase I limitations will impose more stringent requirements on wastewater discharges
from MP&M Phase I sites currently covered by Metal Finishing without undue economic
impacts, and therefore is proposing that MP&M Phase I replace the Metal Finishing
effluent guidelines for sites satisfying the MP&M Phase I criteria.
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Table 3-1
Metal Products and Machinery (MP&M) Phase I Typical Products
Sector
Typical Products
Aircraft
Aircraft
Aircraft engines and engine parts
Aircraft parts and equipment
Aerospace
Guided missiles and space vehicles
Guided missile and space vehicle propulsion
Other space vehicle and missile parts
Electronic Equipment
Telephone and telegraph apparatus
Radio and TV communications equipment
Communications equipment
Electronic tubes
Electronic capacitors
Electronic coils and transformers
Connectors for electronic applications
Electronic components
Electric lamps
Hardware
Cutlery
Hand and edge tools
Hand saws and saw blades
Screw machine products
Bolts, nuts, screws, rivets, washers
Metal shipping barrels, drums, kegs
Iron and steel forgings
Crowns and closures
Metal stampings
Steel springs
Wire springs
Miscellaneous fabricated wire products
Fasteners, buttons, needles, pins
Fluid power valves and hose fittings
Valves and pipe fittings
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Table 3-1 (Continued)
Metal Products and Machinery (MP&M) Phase I Typical Products
Sector
Typical Products
Hardware (Continued)
Fabricated metal pipe and fittings
Fabricated metal products
Machine tools, metal cutting types
Machine tools, metal forming types
Special dies and tools, die sets, jigs
Machine tool accessories and measuring devices
Power-driven hand tools
Heating equipment
Industrial furnaces and ovens
Fabricated structural metal
Fabricated plate work
Sheet metal work
Architectural and ornamental metal work
Prefabricated metal buildings and components
Mobile Industrial
Equipment
Farm machinery and equipment
Garden tractors and lawn and garden equipment
Construction machinery and equipment
Mining machinery and equipment
Hoists, industrial cranes and monorails
Industrial trucks, tractors and trailers
Tanks and tank components
Ordnance
Small arms ammunition
Ammunition
Small arms
Ordnance and accessories
Stationary Industrial
Equipment
Steam, gas hydraulic turbines, generators
Internal combustion engines
Oil field machinery and equipment
Elevators and moving stairways
Conveyors and conveying equipment
Industrial patterns
Rolling mill machinery and equipment
Metal working machinery
Textile machinery
Woodworking machinery
Paper industries machinery
Printing trades machinery and equipment
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Table 3-1 (Continued)
Metal Products and Machinery (MP&M) Phase I Typical Products
Sector
Typical Products
Stationary Industrial
Equipment (Continued)
Food products machinery
Special industry machinery
Pumps and pumping equipment
Ball and roller bearings
Air and gas compressors
Blowers and exhaust and ventilation fans
Packaging machinery
Speed changers, high-speed drivers and gears
Industrial process furnaces and ovens
Mechanical power transmission equipment
General industrial machinery
Automatic vending machines
Commercial laundry equipment
Refrigeration and air and heating equipment
Measuring and dispensing pumps
Service industry machines
Fluid power cylinders and actuators
Fluid power pumps and motors
Scales and balances, except laboratory
Industrial machinery
Welding apparatus
Transformers
Switchgear and switchboard apparatus
Motors and generators
Relays and industrial controls
Electric industrial apparatus
Heavy construction equipment rental
Source: MP&M DCPs, MP&M site visits, technical literature.
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
This section summarizes the Agency's data collection activities for Phase I of the MP&M
industry. Sections 4.1 and 4.2 summarize the purpose, recipient selection process, types
of information collected, and uses of data for the MP&M mini data collection portfolio
(MDCP) and the MP&M data collection portfolio (DCP), respectively. Sections 4.3 and
4.4 summarize the site visit and field sampling programs, respectively, conducted at
MP&M sites.
4.1 Mini Data Collection Portfolio
In August and September 1990, EPA mailed 8,342 screener questionnaires, or MDCPs,
to sites believed to be engaged in MP&M manufacturing, rebuilding, or maintenance
activities. Mailout of the MDCP was the preliminary step in an extensive data-gathering
effort for the MP&M category. The purpose of the MDCP was to identify sites to
receive the more detailed DCP and to make a preliminary assessment of Phase I of the
MP&M industry.
4.1.1 MDCP Recipient Selection and Mailing
The Agency sent the MDCP to randomly selected MP&M Phase I sites engaged in
manufacturing, rebuilding, or maintenance operations. The MDCP was also sent to
selected MP&M Phase II manufacturing sites to characterize the interfaces between
MP&M phases. Potential recipients were identified using Standard Industrial
Classification (SIC) codes. The MDCP was not sent to sites with SIC codes indicating
that the sites were engaged in MP&M Phase II rebuilding or maintenance operations.
EPA calculated the number of sites to receive the MDCP within each SIC code by a
coefficient of variation (CV) minimization procedure, described in Appendix B of the
January 9, 1995 "Data Base Summary Report for the Metal Products and Machinery
Mini Data Collection Portfolio," also referred to as the MDCP Database Report. The
Agency identified more than 190 SIC codes applicable to MP&M sectors. Within each
sector, EPA identified between 1 and 40 SIC codes. Based on the number of sites
selected within each SIC code, the Agency purchased a list of randomly selected names
and addresses from Dun & Bradstreet. This list included twice the number of sites
specified by the CV minimization procedure for each SIC code. Within each SIC code,
Dun & Bradstreet randomly selected the requested number of sites from the Dun &
Bradstreet database. From this list of potential recipient sites, the Agency randomly
selected sites to receive the MDCP.
EPA deleted sites from the Dun & Bradstreet list for the following reasons: sites had
SIC codes which were inconsistent with company names; sites were corporate
headquarters without manufacturing, rebuilding, or maintenance operations; or sites had
insufficient mailing addresses. The remaining site names were scrambled randomly by
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
computer and resorted by SIC code. MDCP recipients were then selected sequentially
by SIC code from the database and assigned a randomly selected site identification
number. Each site identification number was assigned a corresponding barcode to track
the mailout and processing of the MDCPs. Within each SIC code, MDCPs were sent to
approximately 30 to 60 sites.
EPA established a toll-free helpline from August through October of 1990 to assist
MDCP recipients in completing the questionnaire. This helpline received approximately
900 calls from MDCP recipients. Additional information about the MDCP mailing (e.g.,
a copy of the MDCP, specific mailing and processing procedures, MDCP responses,
follow-up letters, and notes from helpline telephone conversations) is discussed in the
following sections and is contained in the administrative record for this rulemaking.
4.1.2 Information Collected
The Agency requested the following site-specific information in the MDCP:
• Name and address of facility;
• Contact person;
• Parent company;
• Sectors in which the site manufactures, rebuilds, or maintains
machines or metal components;
• SIC codes corresponding to products at the site;
• Number of employees;
• Annual revenues;
• Unit operations performed at the site;
• Whether there is process water use and/or wastewater discharge for
each unit operation performed at the site; and
• Base metal(s) on which each unit operation is performed.
The Agency used a computerized database system to store and analyze data received
from the MDCPs. The MDCP database and database dictionary are contained in the
administrative record for this rulemaking.
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4.1.3
MDCP Data Entry, Engineering Coding, and Analysis
The Agency performed a preliminary review of the MDCPs prior to data entry. As part
of this effort, the Agency reviewed all documentation provided by the site, corrected
errors and deficiencies, and formatted the information for data entry. In some cases,
these revisions required telephone contact with site personnel. The Agency contacted
more than 1,100 MDCP recipients to resolve questionnaire deficiencies and format
information for data entry. Following preliminary review, scannable data (i.e., responses
to multiple-choice, Mark Sense™ questions) were entered into the database using a
Scantron™ reader. Each form was scanned twice, and the information was compared
using a computer program as a quality control (QC) check. Nonscannable data were
manually entered twice into computer files, and the computer files compared for
discrepancies, resolved, and finally converted to database files.
4.1.4
MDCP Mailout Results
EPA initially mailed 8,000 MDCP questionnaires in August 1990. Based on the number
of questionnaires returned undelivered, an additional 342 were mailed in September
1990. In addition, EPA received 22 unsolicited responses to the questionnaire. Of the
8,364 potential respondents to the MDCP, including those who provided unsolicited
responses, 94% (7,846) received the MDCP. MDCPs for the remaining 6% (518) were
returned to EPA as undeliverable. These sites were assumed to be out of business. Of
the total potential respondents, 84% (6,981) returned the MDCP to EPA. A blank copy
of the MDCP form and nonconfidential portions of the completed MDCPs are contained
in the administrative record for this rulemaking. A summary of mailout results is
presented in the following table.
Summary of MDCP Mailout Results
Number of Sites
Mailed MDCP
Unsolicited Responses
Total Potential Respondents(a>
Received MDCP at Site(a)
MDCP Undelivered
Returned MDCP to EPA(a)
MDCP Not Returned to EPA
Total Sites
8,342
22
8,364
7,846
518
6,981
865
Percentage of Total Potential
Respondents
—
—
—
94
6
84
10
'"'Includes 22 unsolicited responses.
Source: MDCP Tracking System.
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The number of sites engaged in MP&M operations was determined by responses to the
MDCP. As shown in the following table, approximately 52% of the MDCP respondents
reported that the site was engaged in MP&M operations and approximately
48% reported no MP&M operations at the site. The status of 10 of the sites could not
be determined; these sites returned an incomplete MDCP and did not respond to follow-
up efforts.
Summary of MDCP Respondents
Number of Sites
Returned MDCP
Engaged in MP&M Operations
Not Engaged in MP&M Operations
Unresolved
Total Sites
6,981
3,598
3,373
10
Percentage of Sites
That Returned MDCP
100
52
48
<1
Source: MDCP Database.
The Agency contacted a statistically representative sample of the nonrespondent sites
(i.e., sites that did not return the MDCP) and sites reporting "not engaged" in MP&M
operations to determine whether sites did not respond or had indicated "not engaged"
due to confusion over the scope of the MP&M industry. Many callers to the helpline
questioned the MDCP applicability due to the "Machinery Manufacturing" reference in
the questionnaire title. Callers at sites that produced metal products not traditionally
referred to as machines (e.g., screws or hammers) did not initially understand that the
MP&M industry includes metal products and machine parts as well as machines. The
results of this follow-up are presented in Appendix C of the MDCP Database Report.
This report is contained in the administrative record for this rulemaking.
4.1.5 Industry Scale-Up of MDCP Data
Based on the MDCP mailout results, EPA developed an MP&M Phase I industry profile.
The MDCP Database Report provides estimates of the national population of MP&M
Phase I sites with regard to water use characteristics, size, location, sector, unit
operations, and metal types. Appendix B of the report discusses the sample size
determination and statistical procedures for scale-up to the industry.
4.2 Data Collection Portfolio
Based on responses to the MDCP, EPA sent a more detailed questionnaire to a select
group of water-using MP&M sites. This questionnaire, or data collection portfolio
(DCP), was designed to collect detailed technical and financial information. This
information was used to characterize MP&M Phase I sites, develop pollutant loadings
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
and reductions, and develop compliance cost estimates, as discussed throughout this
document.
EPA mailed 896 DCPs in January 1991. Based on the number of DCPs returned
undelivered, an additional 124 DCPs were mailed in January and February 1991, for a
total of 1,020 DCPs mailed. A blank copy of the DCP is contained in the administrative
record for this rulemaking. Copies of the nonconfidential portions of the completed
DCPs are also contained in the administrative record for this rulemaking.
4.2.1 DCP Recipient Selection and Mailing
EPA selected 1,020 DCP recipients from the following three groups of sites:
• Water-discharging Phase I MDCP respondents (860 recipient sites);
• Water-using Phase I MDCP respondents that did not discharge
process water (74 recipient sites); and
• Water-discharging sites from key Phase I companies that did not
receive the MDCP (86 recipient sites).
The methods used to select sites within each group are described below.
The Agency mailed the DCP to all 860 Phase I water-discharging MDCP respondents.
EPA's intent in collecting detailed data from all 860 sites was to characterize the
potential variations in unit operations performed and water use practices among water-
discharging sites in the MP&M Phase I industry.
The Agency mailed the DCP to a probability sample of 50 MDCP respondents that
reported using but not discharging process water. These sites were selected to provide
information on water-use practices at sites that use but do not discharge process water,
and to determine if "zero-discharge" practices used at those sites could be used at other
MP&M sites.
EPA also mailed the DCP to an additional 24 MDCP respondents that reported using
but not discharging process water. These sites were selected to provide information on
unit operations performed at these sites that were not expected to be sufficiently
characterized by DCPs mailed to other sites. Specific reasons for selecting each of these
24 sites (i.e., unit operations expected at each site) are contained in the administrative
record for this rulemaking.
EPA mailed the DCP to 86 sites that did not receive the MDCP. The Agency identified
these sites to represent key companies in the MP&M Phase I industry that were not
selected as DCP recipients based on the MDCP mailout. Key companies were identified
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from Dun and Bradstreet company listings, the Thomas Register, Fortune Magazine's
listing of the top 500 U.S. companies, and MP&M site visits at companies with annual
revenues of $50 million or more that were believed to be leading companies in their
particular MP&M sector. The Agency contacted each of the key companies to identify
sites within the company that were engaged in MP&M operations and used process
water to perform MP&M operations. Records of these follow-up telephone calls are
contained in the administrative record for this rulemaking.
EPA operated a toll-free telephone helpline from January until July 1991 to assist
recipients in completing the DCP. The helpline received approximately 1,400 calls from
DCP recipients. Callers to the DCP helpline typically requested the following:
• Assistance with the technical sections of the DCP (e.g., technical
clarification of unit operation definitions);
• Additional time to complete the questionnaire;
• Assistance with the financial sections of the DCP (these calls were
referred to a separate economics helpline); or
• Clarification of the applicability of the questionnaire (i.e., did the
questionnaire apply to the site?).
Records for telephone calls to the helpline and to EPA personnel are contained in the
administrative record for this rulemaking.
4.2.2 Information Collected
This section describes the information collected in each part of the DCP, and the
reasons for information collection. Further details on the types of information collected
and the potential uses of the information are contained in the DCP instructions and the
Information Collection Request (ICR) for this project. These documents are contained
in the administrative record for this rulemaking.
The Agency designed the DCP to collect information necessary for the development of
effluent guidelines and standards for the MP&M industry. The DCP was divided into
the following six parts, described below:
• Part I - General Information;
• Part II - Process Information;
• Part III - Water Supply;
• Part IV - Wastewater Treatment and Discharge;
• Part V - Process and Hazardous Wastes; and
• Part VI - Financial and Economic Information.
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
Part I (questions 1 through 13) requested information necessary to identify the site, to
characterize the site by certain variables (including number of employees, facility age,
and location), and to confirm that the site was engaged in MP&M operations. This
information included: site name, address, contact person, number of employees, facility
age, average energy usage, discharge permit status, and MP&M activity (manufacturing,
rebuilding, or maintenance).
Part II (questions 14 through 21) requested detailed information on MP&M products,
production levels, unit operations, activity, water use for unit operations, wastewater
discharge from unit operations, miscellaneous wastewater sources, waste minimization
practices (e.g., pollution prevention), and air pollution control for unit operations. The
site was requested to provide detailed technical information (e.g., water balance,
chemical additives, metal type processed, disposition of wastewater) for each MP&M
unit operation and air pollution control device using process water. This section also
requested information on unique and/or auxiliary MP&M operations. This information
was used to evaluate raw waste characteristics, water use and discharge practices, and
sources of pollutants for each MP&M unit operation.
Part III (question 22) requested information on the water supply for the site. The site
was required to specify the source water origin, average intake flow, average intake
operating hours, and the percentage of water used for MP&M operations. This
information was used to evaluate overall water use for the site.
Part IV (questions 23 through 33) requested detailed information on MP&M influent
and effluent wastewater treatment streams and wastewater treatment operations. The
information requested included: the origin of each stream contributing to the site's
overall wastewater discharge; a block diagram of the wastewater treatment system;
detailed technical information (e.g., wastewater stream flow rates, treatment chemical
additives, system capacity, disposition of treatment sludge) for each wastewater treatment
operation; self-sampling monitoring data; and capital and operating cost data. EPA
collected this information to evaluate treatment in place at MP&M sites, to develop and
design a cost model for Phase I of the MP&M industry, and to assess the long-term
variability of MP&M effluent streams.
Part V (question 34) requested detailed information on the types, amounts, and
composition of wastewater and solid/hazardous wastes generated during production or
waste treatment, and the costs of solid waste disposal. This information was collected to
evaluate the types and amounts of wastes currently discharged, the amount of waste that
is contract hauled off site, and the cost of contract hauling wastes.
Part VI requested detailed financial and economic information from the site and the
company owning the site. Information from this part presented in the Industry Profile
and Economic Impact documents for Metal Products and Machinery Industry Phase I,
which are both included in the administrative record for this rulemaking.
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
4.2.3 DCP Review, Coding, and Data Entry
The Agency completed a detailed engineering review of the DCPs, including coding
responses to questions from Parts I through V of the DCPs to facilitate entry of technical
data into the DCP database. The MP&M DCP Database Dictionary identifies all
database codes developed for this effort. This database dictionary is contained in the
administrative record for this rulemaking. The database dictionary for Section VI of the
DCP is included as Appendix A of the Industry Profile document.
The Agency followed up with telephone calls to all respondents who: (1) did not provide
information on operations (manufacturing, rebuilding, or maintenance) or sectors; (2) did
not provide metal type or unit operation descriptions for each water-using unit operation;
or (3) did not provide descriptions for each wastewater treatment operation. Other
follow-up calls were made to clarify incomplete or contradictory technical or economic
information. Information obtained from all follow-up calls was confirmed by sending a
follow-up letter to the site.
EPA developed a database to store all technical data provided in the DCPs. The
database was developed using dBASE IV® for data entry, and was converted to SAS®
format for data analysis. After engineering review and coding, data from the DCPs were
entered into the database using a double keypunch and verification procedure. Data
from 792 DCPs were coded and entered into the DCP database. The MP&M DCP
Database dictionary presents the database structure and defines each field in the DCP
database and the codes that describe data in these fields.
4.2.4 DCP Mai lout Results
The following table summarizes the results of the DCP mailout. Of the 1,020 sites that
received the DCP, 998 responded to the survey and 22 did not. Of the sites that
responded, 199 were deactivated (i.e., removed from the DCP database development
process) for one of the following reasons:
• The site was out of business;
• The site did not use process water;
• The site was not engaged in MP&M operations;
• Process information at the site was Department of Defense or
Department of Energy classified information; or
• The site did not respond to the data collection effort, and based on
the MDCP and follow-up, was believed by EPA to have limited
useful technical information to add to the DCP database.
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
Specific reasons for deactivation of individual sites are contained in the administrative
record for this rulemaking.
The following table also shows that 87 Phase II (only) sites returned the DCP. The
scope of the DCP mailout effort included only Phase I sites; these 87 sites were
identified during the DCP mailing list development as Phase I sites. Upon review of the
DCPs submitted by these sites, the sites were reclassified as Phase II (only) sites. As
discussed in Section 3.0, all Phase I and Phase II overlap sites are included in the
Phase I rulemaking.
Summary of DCP Mailout Results
Activity
Mailed DCP
Deactivated(a)
Non-Respondent Sites
Respondent Sites
Received Late/Not in Database^
Data Entered into Database
Both Phase I and Phase II(c)
Phase II Only(d)
Phase I Only
Number of Sites
1,020
199
22
799
7
792
75
87
630
'"'Reasons for deactivating (i.e., removing from the database development process) each of these sites are
presented in the administrative record for this rulemaking.
""'These DCPs were received too late to be incorporated into the DCP database based on the
court-mandated schedule for promulgation of effluent guidelines for this category.
'"'These sites are included in both phases based on the products manufactured and the economic sectors in
which the products are sold.
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
4.3
Site Visits
The Agency visited 98 MP&M sites between 1986 and 1993 to collect information about
MP&M unit operations, water use practices, pollution prevention and treatment
technologies, and waste disposal methods, and to evaluate sites for potential inclusion in
the MP&M sampling program (described in Section 4.4). In general, the Agency visited
sites to encompass the range of sectors, unit operations, and wastewater treatment
technologies within the MP&M industry (discussed in Section 4.3.1). The following table
lists the number of sites visited within each MP&M phase and sector. The total number
of site visits presented in this table exceeds 98 because some sites are classified in
multiple sectors.
Number of Sites Visited Within Each MP&M Phase and Sector
Phase I Sectors
Aerospace
Aircraft
Electronic Equipment
Hardware
Mobile Industrial Equipment
Ordnance
Stationary Industrial Equipment
Total
Number of
Sites
Visited
13
24
18
14
6
14
13
Phase II Sectors
Bus and Truck
Household Equipment
Instrument
Motor Vehicle
Office Machines
Precious and Nonprecious Metals
Railroad
Ships and Boats
Total
Number of
Sites
Visited
3
1
0
7
2
0
3
1
Source: MP&M Site Visits.
In addition to sites within the Phase I and Phase II sectors, the Agency visited four job-
shop electroplating sites that performed in-process source reduction and recycling
technologies.
4.3.1
Criteria for Site Selection
The Agency based site selection on information contained in the MP&M MDCPs and
DCPs. The Agency also contacted regional EPA personnel, state environmental agency
personnel, and local pretreatment coordinators to identify MP&M sites believed to be
operating in-process source reduction and recycling technologies or end-of-pipe
wastewater treatment technologies.
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
The Agency used the following four general criteria to select sites that encompassed the
range of sectors and unit operations within the MP&M industry.
1. The site performed MP&M unit operations in an industrial sector in
which sites had not previously been visited. To assess the variation
of unit operations and water use practices across sectors, the Agency
visited sites in each of the seven MP&M Phase I sectors. Site visits
were also conducted at MP&M Phase II sites to assess the variation
of unit operations and water use practices across the MP&M phases.
2. The site performed MP&M unit operations that had not been
observed during previous site visits.
3. The site had water use practices that were believed to be
representative of the best sites within an industrial sector.
4. The site operated in-process source reduction, recycling, or end-of-
pipe treatment technologies considered in development of the
MP&M technology options.
The Agency also attempted to visit sites of various sizes. EPA visited sites with
wastewater flows ranging from less than 200 gallons per day to more than 1,000,000
gallons per day.
Site-specific selection criteria are contained in site visit reports (SVRs) prepared for each
site visited by EPA. The SVRs are contained in the administrative record for this
rulemaking.
4.3.2 Information Collected
During the site visits, EPA collected the following types of information:
• Unit operations performed at the site and the types of metals
processed through these operations;
• Purpose of unit operations performed and purpose for any process
water and chemical additions used by the unit operations;
• Types and disposition of wastewater generated at the site;
• Types of in-process source reduction and recycling technologies
performed at the site;
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• Cross-media impacts of in-process source reduction and recycling
technologies;
• Types of end-of-pipe treatment technologies performed at the site;
and
• Logistical information required for sampling.
This information is documented in the SVRs for each visited site.
4.4
Wastewater and Solid Waste Sampling
The Agency conducted sampling episodes at 27 sites between 1986 and 1993 to obtain
data on the characteristics of MP&M wastewaters and solid wastes, and to assess the
following: the loading of pollutants to surface waters and POTWs from MP&M sites;
the effectiveness of technologies designed to reduce and remove pollutants from MP&M
wastewater; and the variation of MP&M wastewater characteristics across unit
operations, metal types processed in each unit operation, and sectors. The Agency also
sampled wastewater at one job-shop electroplating site to characterize surface treatment
operations (e.g., electroplating, chemical conversion coating) and end-of-pipe treatment
systems that were comparable to MP&M unit operations and treatment systems. The
following table lists the number of sites sampled within each MP&M phase and sector.
The number of sampled sites presented in the table exceeds 27 because one site was
classified in both the aircraft and stationary industrial equipment sectors.
Number of Sites Sampled Within Each MP&M Phase and Sector
Phase I Sectors
Aerospace
Aircraft
Electronic Equipment
Hardware
Mobile Industrial Equipment
Ordnance
Stationary Industrial Equipment
Total Number
of Sites Sampled
2
5
3
3
2
3
4
Phase II Sectors
Bus and Truck
Household Equipment
Instrument
Motor Vehicle
Office Machines
Precious and Nonprecious Metals
Railroad
Ships and Boats
Total
Number of Sites
Sampled
1
0
0
3
1
0
1
0
Source: MP&M Sampling Episodes.
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
4.4.1 Criteria for Site Selection
The Agency used information collected during MP&M site visits to identify candidate
sites for sampling. The Agency used the following general criteria to select sites for
sampling:
• The site performed MP&M unit operations that had not been
sampled at other sites;
• The site processed metals through MP&M unit operations for which
the metal type/unit operation combination had not been sampled at
other sites;
• The site performed in-process source reduction, recycling, or end-of-
pipe treatment technologies that were considered for technology
option development; and
• The site performed unit operations in a sector in which samples had
not previously been collected.
The Agency also attempted to sample at sites of various sizes. EPA sampled at sites
with wastewater flows ranging from less than 200 gallons per day to more than
600,000 gallons per day.
After a site was selected for sampling, the Agency prepared a detailed sampling and
analysis plan (SAP), based on the information contained in the SVR and follow-up
correspondence with the site. The SAPs were prepared to ensure collection of samples
that would be representative of the sampled waste streams, and contained the following
types of information: site-specific selection criteria for sampling; information about site
operations; sampling point locations and sample collection, preservation, and
transportation procedures; site contacts; and sampling schedules.
4.4.2 Information Collected
In addition to wastewater and solid waste samples, the Agency collected the following
types of information during each sampling episode:
• Dates and times of sample collection;
• Flow data corresponding to each sample;
• Production data corresponding to each sample of wastewater from
MP&M unit operations;
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
• Design and operating parameters for source reduction, recycling,
and treatment technologies characterized during sampling;
• Information about site operations that had changed since the site
visit or which were not included in the SVR; and
• Temperature and pH of the sampled waste streams.
All data collected during sampling episodes are documented in the sampling episode
report for each sampled site. Sampling episode reports are included in the
administrative record for this rulemaking. The sampling episode reports also contain
preliminary technical analyses of treatment system performance (where applicable) as
compared to treatment performance data collected for previous metals industry
regulatory development efforts.
4.4.3 Sample Collection and Analysis
All samples were collected, preserved, and transported according to EPA protocols as
specified in EPA's Sampling and Analysis Procedures for Screening of Industrial
Effluents for Priority Pollutants (1) and the MP&M Quality Assurance Plan (QAP).
These documents are contained in the administrative record for this rulemaking.
In general, composite samples were collected from wastewater streams with compositions
that were expected to vary over the course of a production period (e.g., overflowing rinse
waters, wastewaters from continuous recycling and treatment systems). Grab samples
were collected from unit operation baths or rinses that were not continuously discharged
and not expected to vary over the course of a production period. Composite samples of
wastewater treatment sludge were also collected. EPA collected the required types of
quality control samples as described in the MP&M QAP, such as blanks and duplicate
samples, to verify the precision and accuracy of sample analyses.
Samples were shipped via overnight air transportation to EPA-approved laboratories
where analyses for metal and organic pollutants and additional parameters (including
several water quality parameters) were performed. Metal pollutants were analyzed using
EPA Method 1620 (2), volatile organic pollutants were analyzed using EPA Method 1624
(3), and semivolatile organic pollutants were analyzed using EPA Method 1625 (4).
Tables 4-1 and 4-2 (at the end of this section) list the metal and organic pollutants,
respectively, analyzed using these methods. Table 4-1 also lists additional metal
pollutants that were analyzed in the MP&M sampling program, but, as per EPA Method
1620, were not subject to the rigorous quality assurance/quality control procedures
established by the QAP. These metals analyses were used for screening purposes, and
the metals were not selected for regulation in this rulemaking (see Section 8.0).
Additional parameters, including several water quality parameters, were analyzed using
analytical methods contained in EPA's Methods for Chemical Analysis of Water and
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
Wastes (5). Table 4-3 lists these parameters, along with the method and technique used
to analyze for each parameter. Method descriptions are included in the MP&M QAP.
The specific parameters measured in each sample are listed in the sampling episode
report for each sampling episode.
Quality control measures used in performing all analyses complied with the guidelines
specified in the analytical methods and in the MP&M QAP. All analytical data were
reviewed to ensure that these measures were followed and that the resulting data were
within the QAP-specified acceptance criteria for accuracy and precision.
As discussed previously, upon receipt and review of the analytical data for each site, a
sampling episode report was written to document the sampling episode, the data
collected during sampling, the analytical results, and the technical analyses of the results.
The sampling and analysis plans and correspondence with site personnel are included as
appendices to the sampling episode reports.
4.5 Existing Data Sources
In developing the MP&M Phase I effluent guidelines, EPA evaluated the following
existing data sources:
1. EPA/EAD databases from development of effluent guidelines for
other metals industries;
2. The Office of Research and Development (ORD) Risk Reduction
Engineering Laboratory (RREL) treatability database;
3. The Fate of Priority Pollutants in Publicly Owned Treatment Works
(50 POTW Study) database;
4. The Domestic Sewage Study; and
5. The Toxics Release Inventory (TRI) database.
These data sources and their uses for the development of the MP&M Phase I effluent
guidelines are discussed below.
4.5.1 EPA/EAD Databases
As discussed in Section 2.0, EPA has promulgated effluent guidelines for 13 metals
industries. In developing these effluent guidelines, EPA collected wastewater samples to
characterize the unit operations and treatment systems at sites in these industries. Many
of the sampled unit operations and treatment systems are operated at MP&M sites;
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
therefore, EPA evaluated these data for transfer to the MP&M effluent guidelines
development effort.
For the MP&M Phase I pollutant loading and wastewater characterization efforts, EPA
reviewed the data collected for unit operations performed at both MP&M sites and at
sites in other metals industries. EPA reviewed the Technical Development Documents
(TDDs), sampling episode reports, and supporting record materials for the other metals
industries to identify available data. EPA transferred data for unit operations that met
the following two criteria:
1. The unit operation was performed at MP&M Phase I sites; and
2. EPA had not collected analytical data for the unit operation from
MP&M sites.
EPA combined these data with data collected from the MP&M sampling program.
For the MP&M technology effectiveness assessment effort, EPA reviewed data collected
to characterize treatment systems sampled for the development of effluent guidelines for
other metals industries. For several previous effluent guidelines, EPA used treatment
data from metals industries to develop the Combined Metals Data Base (CMDB), which
served as the basis for developing limits for these industries. EPA also developed a
separate database used as the basis for limits for the Metal Finishing category. EPA
used the CMDB and Metal Finishing data as a guide in identifying well-designed and
well-operated MP&M treatment systems. EPA did not use these data in developing the
MP&M technology effectiveness concentrations since sufficient data were collected from
MP&M Phase I sites to develop technology effectiveness concentrations.
4.5.2 Risk Reduction Engineering Laboratory Treatability Database
EPA's Office of Research and Development (ORD) developed the Risk Reduction
Engineering Laboratory (RREL) treatability database to provide data on the removal
and destruction of chemicals in various types of media, including water, soil, debris,
sludge, and sediment. This database contains treatability data from publicly owned
treatment works (POTWs) for various pollutants. This database includes physical and
chemical data for each pollutant, the types of treatment used to treat the specific
pollutants, the type of wastewater treated, the size of the POTW, and the treatment
concentrations achieved. EPA used this database to assess removal by POTWs of
MP&M pollutants of concern.
4.5.3 Fate of Priority Pollutants in Publicly Owned Treatment Works Database
In September 1982, EPA published the Fate of Priority Pollutants in Publicly Owned
Treatment Works (6), referred to as the 50 POTW Study. The purpose of this study was
4-16
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
to generate, compile, and report data on the occurrence and fate of the 129 priority
pollutants in 50 POTWs. The report presents all of the data collected, the results of
preliminary evaluations of these data, and the results of calculations to determine the
following:
1. The quantity of priority pollutants in the influent to POTWs;
2. The quantity of priority pollutants discharged from the POTWs;
3. The quantity of priority pollutants in the effluent from intermediate
process streams; and
4. The quantity of priority pollutants in the POTW sludge streams.
EPA used the data from this study to assess removal by POTWs of MP&M pollutants of
concern.
4.5.4 The Domestic Sewage Study
In February 1986, EPA issued the Report to Congress on the Discharge of Hazardous
Wastes to Publicly Owned Treatment Works (7), referred to as the Domestic Sewage
Study (DSS). This report, which was based in part on the 50 POTW Study, revealed a
significant number of sites discharging pollutants to POTWs which are a threat to the
treatment capability of the POTW. These pollutants were not regulated by national
effluent regulations. Some of the major sites identified were in the metals industries,
particularly one called equipment manufacturing and assembly. This industry included
sites which manufacture such products as office machines, household appliances,
scientific equipment, and industrial machine tools and equipment. The DSS estimated
that this category discharges 7,715 metric tons per year of priority hazardous organic
pollutants which are presently unregulated. Data on priority hazardous metals discharges
were unavailable for this category. Further review of the DSS revealed other categories
which were related to metals industries, namely the motor vehicle category, which
includes servicing of new and used cars and engine and parts rebuilding, and the
transportation services category, which includes railroad operations, truck service and
repair, and aircraft servicing and repair. EPA used the information in the DSS in
developing the Preliminary Data Summary (PDS) for the MP&M category.
4.5.5 Toxics Release Inventory Database
The Toxics Release Inventory (TRI) database contains specific toxic chemical release
and transfer information from manufacturing facilities throughout the United States.
This database was established under the Emergency Planning and Community Right-to-
Know Act of 1986 (EPCRA), which Congress passed to promote planning for chemical
emergencies and to provide information to the public about the presence and release of
4-17
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4.0 SUMMARY OF DATA COLLECTION ACTIVITIES
toxic and hazardous chemicals. Each year, manufacturing facilities meeting certain
activity thresholds must report the estimated releases and transfers of listed toxic
chemicals to EPA and to the state or tribal entity in whose jurisdiction the facility is
located. The TRI list includes more than 300 chemicals in 20 chemical categories.
EPA considered using the TRI database for developing the MP&M effluent guidelines.
EPA did not use TRI data on wastewater discharges from MP&M sites because
sufficient data were not available for effluent guidelines development. For example, in
development of the MP&M effluent guidelines, production data were used that could be
linked directly to pollutant loadings. This information was used to normalize pollutant
loadings to production. The linked production and pollutant loadings data are not
available in the TRI database. EPA also did not use the data on wastewater discharges
because many MP&M Phase I sites don't meet the reporting thresholds for the TRI
database.
4-18
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Table 4-1
Metal Constituents Measured Under the MP&M Sampling Program
(EPA Method 1620)
Metal Constituents
ALUMINUM
ANTIMONY
ARSENIC
BARIUM
BERYLLIUM
BORON
CADMIUM
CALCIUM
CHROMIUM
COBALT
COPPER
IRON
LEAD
MAGNESIUM
MANGANESE
MERCURY
MOLYBDENUM
NICKEL
SELENIUM
SILVER
SODIUM
THALLIUM
TIN
TITANIUM
VANADIUM
YTTRIUM
ZINC
Additional Metal Constituents*"' Not Subject to Rigorous QA/QC Procedures Per
Method 1620:
BISMUTH
CERIUM
DYSPROSIUM
ERBIUM
EUROPIUM
GADOLINIUM
GALLIUM
GERMANIUM
GOLD
HAFNIUM
HOLMIUM
INDIUM
IODINE
IRIDIUM
LANTHANUM
LITHIUM
LUTETIUM
NEODYMIUM
NIOBIUM
OSMIUM
PALLADIUM
PHOSPHORUS
PLATINUM
POTASSIUM
PRASEODYMIUM
RHENIUM
RHODIUM
RUTHENIUM
SAMARIUM
SCANDIUM
SILICON
STRONTIUM
SULFUR
TANTALUM
TELLURIUM
TERBIUM
THORIUM
THULIUM
TUNGSTEN
URANIUM
YTTERBIUM
ZIRCONIUM
-------
Table 4-2
Organic Constituents Measured Under the MP&M Sampling Program
(EPA Methods 1624 and 1625)
Volatile Organic Constituents (EPA Method 1624)
ACRYLONITRILE
BENZENE
BROMODICHLOROMETHANE
BROMOMETHANE
CARBON BISULFIDE
CHLOROACETONITRILE
CHLOROBENZENE
CHLOROETHANE
CHLOROFORM
CHLOROMETHANE
CIS-1,3-DICHLOROPROPENE
CROTONALDEHYDE
DIBROMOCHLOROMETHANE
DIBROMOMETHANE
DIETHYL ETHER
ETHYL CYANIDE
ETHYL METHACRYLATE
ETHYLBENZENE
IODOMETHANE
ISOBUTYL ALCOHOL
M-XYLENE
METHYL METHACRYLATE
METHYLENE CHLORIDE
O + PXYLENE
TETRACHLOROETHENE
TETRACHLOROMETHANE
TOLUENE
TRANS- 1,2-DICHLOROETHENE
TRANS- 1,3-DICHLOROPROPENE
TRANS-1.4-DICHLORO-2-BUTENE
TRIBROMOMETHANE
TRICHLOROETHENE
TRICHLOROFLUOROMETHANE
VINYL ACETATE
VINYL CHLORIDE
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-DIBROMOETHANE
1,2-DICHLOROETHANE
1,2-DICHLOROPROPANE
1,2,3-TRICHLOROPROPANE
1,3-BUTADIENE, 2-CHLORO
1,3-DICHLOROPROPANE
1,4-DIOXANE
2-BUTANONE
2-CHLOROETHYL VINYL ETHER
2-HEXANONE
2-PROPANONE
2-PROPEN-l-OL
2-PROPENAL
2-PROPENENITRILE, 2-METHYL-
3-CHLOROPROPENE
4-METHYL-2-PENTANONE
Semivolatile Organic Constituents (EPA Method 1625)
ACENAPHTHENE
ACENAPHTHYLENE
ACETOPHENONE
ALPHA-TERPINEOL
ANILINE
ANILINE, 2,4,5-TRIMETHYL-
ANTHRACENE
ARAMITE
BENZANTHRONE
BENZENETHIOL
BENZIDINE
BENZO(A)ANTHRACENE
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
4-20
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Table 4-2 (Continued)
Organic Constituents Measured Under the MP&M Sampling Program
(EPA Methods 1624 and 1625)
Semivolatile Organic Constituents (EPA Method 1625) (Continued)
BIS(2-CHLOROETHOXY)METHANE
BIS(2-CHLOROETHYL) ETHER
BIS(2-CHLOROISOPROPYL) ETHER
BIS(2-ETHYLHEXYL) PHTHALATE
BUTYL BENZYL PHTHALATE
CARBAZOLE
CHRYSENE
CIODRIN
CROTOXYPHOS
DI-N-BUTYL PHTHALATE
DI-N-OCTYL PHTHALATE
DI-N-PROPYLNITROSAMINE
DIBENZO(A,H)ANTHRACENE
DIBENZOFURAN
DIBENZOTHIOPHENE
DIETHYL PHTHALATE
DIMETHYL PHTHALATE
DIMETHYL SULFONE
DIPHENYL ETHER
DIPHENYLAMINE
DIPHENYLDISULFIDE
ETHANE, PENTACHLORO-
ETHYL METHANESULFONATE
ETHYLENETHIOUREA
FLUORANTHENE
FLUORENE
HEXACHLOROBENZENE
HEXACHLOROBUTADIENE
HEXACHLOROCYCLOPENTADIENE
HEXACHLOROETHANE
HEXACHLOROPROPENE
HEXANOIC ACID
INDENO(1,2,3-CD)PYRENE
ISOPHORONE
ISOSAFROLE
LONGIFOLENE
MALACHITE GREEN
MESTRANOL
METHAPYRILENE
METHYL METHANESULFONATE
N-DECANE
N-DOCOSANE
N-DODECANE
N-EICOSANE
N-HEXACOSANE
N-HEXADECANE
N-NITROSODI-N-BUTYLAMINE
N-NITROSODIETHYLAMINE
N-NITROSODIMETHYLAMINE
N-NITROSODIPHENYLAMINE
N-NITROSOMETHYLETHYLAMINE
N-NITROSOMETHYLPHENYLAMINE
N-NITROSOMORPHOLINE
N-NITROSOPIPERIDINE
N-OCTACOSANE
N-OCTADECANE
N-TETRACOSANE
N-TETRADECANE
N-TRIACONTANE
N,N-DIMETHYLFORMAMIDE
NAPHTHALENE
NITROBENZENE
O-ANISIDINE
0-CRESOL
O-TOLUIDINE
O-TOLUIDINE, 5-CHLORO-
P-CHLOROANILINE
P-CRESOL
P-CYMENE
P-DIMETHYLAMINOAZOBENZENE
P-NITROANILINE
PENTACHLOROBENZENE
PENTACHLOROPHENOL
PENTAMETHYLBENZENE
PERYLENE
PHENACETIN
PHENANTHRENE
PHENOL
PHENOL, 2-METHYL-4,6-DINITRO-
PHENOTHIAZINE
PRONAMIDE
PYRENE
PYRIDINE
RESORCINOL
SAFROLE
SQUALENE
4-21
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Table 4-2 (Continued)
Organic Constituents Measured Under the MP&M Sampling Program
(EPA Methods 1624 and 1625)
Semivolatile Organic Constituents (EPA Method 1625) (Continued)
STYRENE
THIANAPHTHENE
THIOACETAMIDE
THIOXANTHE-9-ONE
TOLUENE, 2,4-DIAMINO-
TRIPHENYLENE
TRIPROPYLENEGLYCOL METHYL ETHER
l-BROMO-2-CHLOROBENZENE
l-BROMO-3-CHLOROBENZENE
l-CHLORO-3-NITROBENZENE
1-METHYLFLUORENE
1-METHYLPHENANTHRENE
1-NAPHTHYLAMINE
1-PHENYLNAPHTHALENE
l,2-DIBROMO-3-CHLOROPROPANE
1,2-DICHLOROBENZENE
1,2-DIPHENYLHYDRAZINE
1,2,3-TRICHLOROBENZENE
1,2,3-TRIMETHOXYBENZENE
1,2,4-TRICHLOROBENZENE
1,2,4,5-TETRACHLOROBENZENE
1,2:3,4-DIEPOXYBUTANE
l,3-DICHLORO-2-PROPANOL
1,3-DICHLOROBENZENE
1,3,5-TRITHIANE
1,4-DICHLOROBENZENE
1,4-DINITROBENZENE
1,4-NAPHTHOQUINONE
1,5-NAPHTHALENEDIAMINE
2-(METHYLTHIO)BENZOTHIAZOLE
2-CHLORONAPHTHALENE
2-CHLOROPHENOL
2-ISOPROPYLNAPHTHALENE
2-METHYLBENZOTHIOAZOLE
2-METHYLNAPHTHALENE
2-NITROANILINE
2-NITROPHENOL
2-PHENYLNAPHTHALENE
2-PICOLINE
2,3-BENZOFLUORENE
2,3-DICHLOROANILINE
2,3-DICHLORONITROBENZENE
2,3,4,6-TETRACHLOROPHENOL
2,3,6-TRICHLOROPHENOL
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-METHYLCHOLANTHRENE
3-NITROANILINE
3,3'-DICHLOROBENZIDINE
3,3'-DIMETHOXYBENZIDINE
3,6-DIMETHYLPHENANTHRENE
4-AMINOBIPHENYL
4-BROMOPHENYL PHENYL ETHER
4-CHLORO-2-NITROANILINE
4-CHLORO-3-METHYLPHENOL
4-CHLOROPHENYL PHENYL ETHER
4-NITROPHENOL
4,4'-METHYLENEBIS(2-CHLOROANILINE)
4,5-METHYLENE PHENANTHRENE
5-NITRO-O-TOLUIDINE
7,12-DIMETHYLBENZ(A)ANTHRACENE
Source: EPA Methods 1624 and 1625.
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Table 4-3
Additional Parameters Measured Under the MP&M Sampling Program
Parameter
Acidity
Alkalinity
Ammonia as Nitrogen
Chemical Oxygen Demand (COD)
Chloride
Cyanide, Total
Fluoride
Nitrogen, Total Kjeldahl
Oil and Grease
pH
Phenolics, Total Recoverable
Phosphorus, Total
Sulfate
Total Dissolved Solids (TDS)
Total Suspended Solids (TSS)
EPA Method
305.1
310.1
350.1
410.1
410.2
325.3
335.2
340.2
351.2
413.2
150.1
420.2
365.4
375.4
160.1
[ 160.2
Source: Reference 5.
4-23
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4.6 References
1. Sampling and Analysis Procedures for Screening of Industrial Effluents for
Priority Pollutants. U.S. Environmental Protection Agency, April 1977.
2. Method 1620 Draft - Metals by Inductively Coupled Plasma Atomic
Emission Spectroscopy and Atomic Absorption Spectroscopy, U.S.
Environmental Protection Agency, September 1989.
3. Method 1624 Revision C - Volatile Organic Compounds by Isotope
Dilution GCMS. U.S. Environmental Protection Agency, June 1989.
4. Method 1625 Revision C - Semivolatile Organic Compounds by Isotope
Dilution GCMS. U.S. Environmental Protection Agency, June 1989.
5. Methods for Chemical Analysis of Water and Wastes. U.S. Environmental
Protection Agency, EPA-600/4-79-020, March 1979.
6. Fate of Priority Pollutants in Publicly Owned Treatment Works, U.S.
Environmental Protection Agency, EPA 440/1-82/303, September, 1982.
7. Report to Congress on the Discharge of Hazardous Wastes to Publicly
Owned Treatment Works, U.S. Environmental Protection Agency, EPA
530-SW-86-004, February, 1986.
4-24
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5.0 INDUSTRY DESCRIPTION
5.0 INDUSTRY DESCRIPTION
As discussed in Section 3.0, the Metal Products and Machinery (MP&M) Point Source
Category covers sites that perform manufacturing, rebuilding, and maintenance activities
while processing metal parts, machinery, or metal products. The category encompasses
two regulatory phases comprising 15 industrial sectors. Phase I of the MP&M category
consists of the following seven industrial sectors: aerospace, aircraft, electronic
equipment, hardware, mobile industrial equipment, ordnance, and stationary industrial
equipment. The MP&M Phase II category includes the remaining eight sectors. A list
of products typically included in each Phase I sector is presented in Section 3.0. A site is
considered to be included in a sector if any products processed at the site are used
within that sector. MP&M sites performing any activities in the Phase I sectors are
included in the Phase I category.
This section provides an overview of the MP&M Phase I industry, including the types of
activities performed, the metal types processed, and detailed descriptions of each unit
operation. This section also presents a discussion of the production-normalizing
parameters applicable to the unit operations and production-normalized flow rates of
wastewater discharged from these operations.
5.1 Number and Size of MP&M Phase I Sites
Based on results of the mini data collection portfolio (MDCP) survey, there are an
estimated 79,613 MP&M Phase I sites. Additional data sources indicate that there may
be as many as 91,000 MP&M Phase I sites. Chapter 3 of the MP&M Economic Impact
Analysis (contained in the administrative record for this rulemaking) discusses these
additional data sources. Based on data collection portfolio (DCP) survey results, an
estimated 10,601 MP&M Phase I sites discharge process water.
MP&M Phase I water-discharging sites range in size from less than 10 employees to sites
with tens of thousands of employees and from wastewater discharge flow rates of less
than 100 gallons per year to wastewater discharge flow rates exceeding 100 million
gallons per year. The following table summarizes the estimated number of MP&M
Phase I sites by number of employees. This table shows that approximately 91% of
MP&M Phase I sites have 500 or fewer employees. However, as discussed in
Section 7.0, the number of employees at a site does not necessarily correspond with the
discharge flow at the site. Section 5.7 of this report presents additional information on
the estimated number of MP&M Phase I sites by discharge flow range.
5-1
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5.0 INDUSTRY DESCRIPTION
MP&M Phase I Water-Discharging Sites by Number of Employees
Number of Employees
1-10
11-50
51-100
101-500
501-1,000
1,001-5,000
5,001-10,000
> 10,000
Total
Estimated Number of Water-
Discharging MP&M Phase I Sites
3,108
1,405
1,806
3,355
423
445
30
29
10,601
Percent of Water-Discharging
MP&M Phase I Sites
29
13
17
32
4
4
<1
<1
100
Source: MP&M Phase I DCP database.
5.2
Unit Operations Performed
MP&M sites perform a wide variety of process unit operations on metal parts. The
MP&M regulatory development effort initially focused on 47 unit operations (and their
associated rinses) performed at MP&M sites, plus wet air pollution control operations,
for a total of 48 unit operations. These unit operations are listed in Table 5-1 and are
defined and described in Section 5.10. During the regulatory development effort, EPA
identified additional unit operations performed at MP&M sites. These additional unit
operations are listed in Table 5-2. Each MP&M unit operation can be characterized as
belonging to one or more of the following types of unit operations:
• Metal shaping operations;
• Surface preparation operations;
• Metal deposition operations;
• Organic deposition operations;
• Surface finishing operations; and
• Assembly operations.
Metal shaping operations (e.g., machining, grinding, impact and pressure deformation)
are mechanical operations that alter the form of raw materials into intermediate and
final product forms. Surface preparation operations (e.g., alkaline treatment, barrel
finishing) are chemical and mechanical operations that remove unwanted materials from
or alter the chemical or physical properties of the surface prior to subsequent MP&M
operations. Metal deposition operations (e.g., electroplating, metal spraying) apply a
5-2
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5.0 INDUSTRY DESCRIPTION
metal coating to the part surface by chemical or physical means. Organic deposition
operations (e.g., painting, corrosion preventive coating) apply an organic material to the
part by chemical or physical means. Metal and organic deposition operations may be
performed to protect the surface from wear or corrosion, modify the electrical properties
of the surface, or alter the appearance of the surface. Surface finishing operations (e.g.,
chromate conversion coating, anodizing sealing) protect and seal the surface of the
treated part from wear or corrosion by chemical means. Some surface finishing
operations (e.g., metal coloring) may also be performed to alter the appearance of the
part surface. Assembly operations (e.g., welding, soldering, testing, assembly,
disassembly) are performed throughout the manufacturing, rebuilding, or maintenance
process.
At a given MP&M site, the specific unit operations performed and the sequence of
operations depend on many factors, including the activity (i.e., manufacturing, rebuilding,
or maintenance), industrial sector, and type of product processed. Depending on these
factors, MP&M sites perform many different combinations and sequences of unit
operations. In general, however, MP&M products are processed in the following
sequence:
• The raw material (e.g., bar stock, sheet stock, plates) undergoes
some type of metal shaping process, such as impact or pressure
deformation, machining, or grinding. In these operations, the raw
material is shaped into intermediate forms for further processing or
into final forms for assembly and shipment to the customer.
Cleaning and degreasing processes are typically performed between
some of the shaping operations to remove lubricants, coolants, and
metal fines from the part. Heat treating operations may also be
performed between shaping operations to alter the physical
characteristics of the part.
• After shaping, the part typically undergoes some type of surface
preparation operation, such as alkaline cleaning, acid pickling, or
barrel finishing. The specific surface preparation operation used
depends on the subsequent unit operations to be performed and the
final use of the products. For example, prior to electroplating, parts
typically undergo acid pickling to prepare the surface of the part for
electroplating. Before assembly, parts typically undergo alkaline
cleaning or barrel finishing. Parts undergo surface preparation
operations at various stages of the production process. As
mentioned above, cleaning and degreasing can occur between metal
shaping operations. Additional cleaning and degreasing also occur
prior to metal deposition, organic deposition, surface finishing, and
assembly operations.
5-3
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5.0 INDUSTRY DESCRIPTION
• Metal and organic deposition operations typically occur after
shaping and surface preparation operations, and prior to surface
finishing and final assembly operations. Electroplating operations
typically follow alkaline and acid treatment operations, while
painting operations typically follow phosphate conversion coating
and alkaline treatment operations.
• Surface finishing operations are typically performed after shaping
and surface preparation operations. Some surface finishing
operations are performed after metal deposition operations. For
example, chromate conversion coating is typically performed after
acid cleaning, though this operation is sometimes performed as a
sealant operation after electroplating. Some surface finishing
operations are also performed prior to organic coating operations.
For example, phosphate conversion coating is frequently performed
prior to painting to enhance the paint adhesion.
• Assembly operations are performed at many steps of the
manufacturing and rebuilding process. Disassembling operations
may be performed as the first step in the rebuilding process.
Assembly operations are performed to prepare the final product.
Assembly may also involve some final shaping operations (e.g.,
drilling and grinding) and surface preparation operations (e.g.,
alkaline cleaning). Final assembly operations are typically the last
operations performed prior to shipment to the customer.
Process water is used for and discharged from many of the unit operations listed in
Tables 5-1 and 5-2. For some operations, process water may or may not be used,
depending on the purpose of the operation, raw materials, and final product use. For
example, some machining operations (e.g., drilling), can often be performed without a
coolant, while other machining operations (e.g., milling) typically require a coolant.
Process water that is used for an operation is typically discharged, but this is not always
the case. Section 5.9 describes sites that use but do not discharge process water.
Table 5-3 provides, for each unit operation (including associated rinses and wet air
pollution control), a summary of the number of MP&M Phase I sites performing each
unit operation, using process water to perform each unit operation, and discharging
process water from each unit operation. The individual unit operations are described in
Section 5.10. The most frequently performed water-discharging operations at MP&M
Phase I sites are alkaline treatment, acid treatment, chemical conversion coating, floor
cleaning, grinding, and machining. Many of the operations are typically followed by
associated rinses.
Some MP&M sites perform all of these types of operations in manufacturing or
rebuilding products, while others may focus on only a portion of these operations. For
5-4
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5.0 INDUSTRY DESCRIPTION
example, a site in the hardware sector may start with bar stock and manufacture a final
hardware product, performing machining, cleaning, electroplating, conversion coating,
painting, degreasing, and assembly operations. Another hardware site may focus on
painting the parts, and only perform cleaning and painting operations. A third hardware
site may focus on shaping the parts, and perform only machining, cleaning, and
degreasing operations.
MP&M sites that repair, rebuild, or maintain products often perform preliminary
operations that may not be performed at manufacturing facilities (e.g., disassembly,
cleaning, or degreasing to remove dirt and oil accumulated during use of the product).
Sites that manufacture products required to meet very strict performance specifications
(e.g., aerospace or electronic components) often perform unit operations, such as gold
electroplating or magnetic flux testing, that may not be performed when manufacturing
other products.
5.3
Metal Types Processed
MP&M sites perform unit operations on a variety of metal types. Based on DCP results,
24 different metal types were identified as processed at MP&M Phase I sites. Of these,
iron, aluminum, and copper are the base metals most frequently processed. Chromium,
nickel, tin, lead, and zinc are also frequently processed as metals electroplated onto base
metals.
Many MP&M sites also process more than one metal type on site. The following table
lists the number of water-discharging sites by number of metal types processed.
MP&M Phase I Water-Discharging Sites by Number of Metal Types Processed
Number of Metal Types
Zero Metal Types(a>
One Metal Type
Two Metal Types
Three Metal Types
Four Metal Types
Five or More Metal Types
Estimated Number of Water-
Discharging MP&M Phase I Sites
48
4,513
3,359
1,616
451
614
Percent of Water-Discharging
MP&M Phase I Sites
<1%
43%
32%
15%
4%
6%
Source: MP&M Phase I DCP database.
'"'Represents sites only discharging process water from floor cleaning of the metals processing area.
5-5
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5.0 INDUSTRY DESCRIPTION
As shown in this table, more than half of the water-discharging MP&M sites process
more than one metal type on site.
5.4 Water-Discharging MP&M Phase I Sites bv Sector
The MP&M Phase I category includes seven industrial sectors. The table below
summarizes the number of MP&M Phase I water-discharging sites by sector. Because
some sites perform operations in more than one of the seven Phase I sectors, the sum of
water-discharging sites by sector exceeds the total number of water-discharging sites (i.e.,
sites were multiple-counted in the table). This table indicates that the smallest number
of water-discharging Phase I sites (316) are in the ordnance sector, while the largest
number of water-discharging sites (4,321) are in the hardware sector.
MP&M Phase I Water-Discharging Sites by Sector
Sector
Estimated Number of Sites That Discharge
Process Water
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5.0 INDUSTRY DESCRIPTION
the metal product. Rebuilding is generally performed in a
production environment.
• Maintenance is the series of unit operations, on original or
replacement components, required to keep metal products in
operating condition. Maintenance is generally performed in a non-
production environment.
The following table summarizes the estimated number of MP&M Phase I water-
discharging sites and baseline (i.e., current) total discharge flow by activity combination.
The largest number of sites (7,527) perform manufacturing only, while the smallest
number of sites (117) perform rebuilding only. Sites performing only manufacturing
account for approximately 19.8 billion gallons of discharge flow annually, which
represents 85% of the total estimated discharge flow for the industry. In contrast, the
discharge flow for the 235 sites performing both rebuilding and maintenance accounts for
less than 1% of the total estimated discharge flow for the industry.
MP&M Phase I Water-Discharging Sites and
Total Discharge Flow by Activity Combination
Activity
Manufacturing, Rebuilding and
Maintenance
Manufacturing Only
Rebuilding Only
Maintenance Only
Manufacturing and Rebuilding
Manufacturing and
Maintenance
Rebuilding and Maintenance
Total
Estimated
Number of Water-
Discharging
MP&M Phase I
Sites
308
7,527
117
841
1,333
240
235
10,601
Total
Estimated
Discharge
Flow (million
gal/yr)(a>
208
19,800
289
66.8
1,950
842
0.350
23,200
Percentage of
Total Water-
Discharging
MP&M
Phase I Sites
3
71
1
8
13
2
2
100
Percentage of
Total
Discharge
Flow
1
85
1
<1
8
4
<1
100
Source: MP&M Phase I DCP database.
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5.0 INDUSTRY DESCRIPTION
Water-Discharging MP&M Phase I Sites and Total Discharge Flow bv
Discharge Status
MP&M Phase I sites include direct discharging sites, indirect discharging sites, and sites
that are both direct and indirect dischargers. An indirect discharger is a site that
discharges wastewater to a publicly-owned treatment works (POTW) or a federally-
owned treatment works (FOTVV). A direct discharger is a site that discharges
wastewater to a surface water. Sites discharging exclusively to privately-owned treatment
works are considered zero dischargers that contract haul to centralized waste treatment
facilities. The following table summarizes the number of MP&M Phase I water-
discharging sites and baseline total discharge flow by discharge status. This table
indicates that 8,440 sites are indirect dischargers, 1,797 sites are direct dischargers, and
364 sites are both direct and indirect dischargers. Indirect dischargers account for
approximately 17.4 billion gallons of discharge flow annually, which represents 75% of
the total estimated discharge flow for the industry. In contrast, the 1,797 direct
dischargers account for approximately 8% of the total estimated discharge flow for the
industry, while the 364 sites that discharge both directly and indirectly account for 17%
of the total flow.
MP&M Phase I Water-Discharging Sites and Total Discharge Flow by Discharge Status
Discharge Status
Indirect Only
Direct Only
Direct and Indirect
Total
Estimated Number
of Water-
Discharging MP&M
Phase I Sites
8,440
1,797
364
10,601
Total Estimated
Discharge Flow
(million
gal/yr)(a>
17,400
1,800
3,920
23,200
Percentage of
MP&M Phase I
Water-Discharging
Sites
80
17
3
100
Percentage of
Total
Discharge
Flow
75
8
17
100
Source: MP&M Phase I DCP database.
(a)Note: Based on the use of significant figures and rounding, the total reported for this column does not
exactly equal the sum of the individual column values.
5.7
Water-Discharging MP&M Phase I Sites by Total Discharge Flow
Wastewater discharge flows from MP&M sites range from less than 100 gallons per year
to greater than 100 million gallons per year. The following table summarizes
information on the wastewater discharge flow ranges for MP&M Phase I sites. As this
table shows, sites discharging more than one million gallons per year (approximately 22%
of the total Phase I sites) account for approximately 96% of the total wastewater
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5.0 INDUSTRY DESCRIPTION
discharge from the industry. In contrast, sites discharging less than 10,000 gallons per
year (approximately 30% of the total Phase I sites) account for less than 0.1% of the
overall wastewater discharge flow for the industry.
MP&M Phase I Water-Discharging Sites by Total Discharge Flow
Discharge
Flow Range
(gal/yr/site)
0- 102
102 - 103
103 - 10"
10" - 10s
10s - 106
106 - 107
107 - 108
>108
Total
Estimated Number
of Water-
Discharging MP&M
Phase I Sites
993
1,297
926
3,056
2,053
1,760
483
33
10,601
Total Estimated
Discharge Flow
(million gal/yr)(a)
0.0455
0.498
4.12
115
676
6,210
12,400
3,800
_ 23,200
Percentage of Water-
Discharging MP&M
Phase I Sites
9
12
9
29
19
17
5
<1
100
Percentage of
Total Discharge
Flow
<1
<1
<1
1
3
27
53
16
100
Source: MP&M Phase I DCP database.
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site visits, and technical literature, these sites achieve zero discharge of process
wastewater in one of the following ways:
• Sites contract haul for off-site disposal all process wastewater
generated on site;
• Sites discharge process wastewater to either on-site septic systems or
deep-well injection systems;
• Sites perform end-of-pipe treatment and reuse all process
wastewater generated on site;
• Sites perform either in-process or end-of-pipe evaporation to
eliminate wastewater discharges; or
• Sites perform in-process recirculation and recycling to eliminate
wastewater discharges.
As discussed in Section 4.0, EPA mailed DCPs to 50 statistically selected sites that were
using but not discharging process water. Based on the DCP responses, five of these sites
were identified as contract hauling all wastewater generated on site, eight were identified
as actually discharging process wastewater, 18 were identified as having no process
wastewater discharges, and 19 were identified as not engaged in MP&M. EPA mailed
an additional 24 DCPs, selected for technical reasons, to sites not discharging process
water. Of these, 14 were identified as actually discharging process wastewater, two were
identified as having no process wastewater discharges, and 8 were identified as not
engaged in MP&M.
In addition to the 20 sites discussed above as having no process wastewater discharges,
35 DCP respondents eliminated wastewater discharge by in-process or end-of-pipe
evaporation, end-of-pipe treatment and reuse, or in-process recirculation and recycling.
The 55 sites eliminating discharges through these methods are discussed below.
In-Process or End-Of-Pipe Evaporation. Eight DCP respondents reported discharging
wastewater to either evaporators or on-site ponds or lagoons for evaporation of process
wastewater. These sites typically performed less than 20 water-discharging unit
operations. None of these site reported recovering the process wastewater. Sludge from
the evaporators was reported as being contract hauled for off-site disposal. Information
was not obtained regarding the impact of these operations on air pollution emissions
from these sites. EPA believes that these types of evaporators may result in significant
air emissions from MP&M sites.
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End-Of-Pipe Treatment and Reuse. Three DCP respondents reported eliminating
wastewater discharge through end-of-pipe treatment and reuse of all wastewater
generated on site. One of these three sites operates an evaporator with an associated
condenser unit to recover and reuse process wastewater. This site performs the following
unit operations: alkaline cleaning, barrel finishing, phosphate conversion coating,
painting, and associated rinses. This site also operates a coolant recycling system to
recycle spent machining coolant. The other two sites reported recycling all spent
machining coolant with units consisting of settling, skimming, and centrifuging. These
two sites performed only machining operations. EPA also performed one site visit at a
site that treated and reused all process wastewater using a system consisting of chemical
precipitation and settling, ion exchange, and evaporation/condensation. As discussed in
Sections 10 and 15, EPA considered end-of-pipe ion exchange with wastewater reuse in
development of the MP&M Phase I effluent guidelines, but determined that this
technology was not cost-effective in removing pollutants from MP&M Phase I sites.
In-Process Recirculation and Recycling. Forty-four sites reported eliminating wastewater
discharge through in-process recirculation and recycling. Most of these sites perform
fewer than three wastewater-generating unit operations; one site performs six
wastewater-generating unit operations and another performs five wastewater-generating
unit operations. The majority of these sites perform grinding and machining operations,
in which water-based coolant is continuously recirculated through the machining unit and
is not discharged. Make-up water is added for evaporation. Several sites perform heat
treating operations, in which a stagnant water quench is used and not discharged. Some
sites perform hydraulic testing, in which water is used to pressure test a part and is not
discharged. Some sites perform surface finishing operations such as alkaline cleaning
and chemical conversion coating, in stagnant baths and do not discharge wastewater.
Make-up water is added for evaporation. Based on the data from MP&M sites, only
sites with few unit operations are typically able to achieve zero discharge solely through
in-process recirculation and recycling.
5.10 MP&M Unit Operations and Rinses
This section describes each of the 48 MP&M unit operations listed in Table 5-1 and
summarizes the purpose of process water use for each operation and associated rinse.
Table 5-3 provides, for each unit operation (including associated rinses), a summary of
the number of MP&M sites performing each operation, using water to perform each unit
operation, and discharging process water from each unit operation. Table 5-4 presents
the production-normalizing parameter, median production-normalized flow, purpose of
process water, and estimated total industry discharge flow for each unit operation.
Production-normalizing parameters and production-normalized flows are described in
Section 5.11. As shown in Table 5-4, most wastewater is discharged from associated
rinses, with acid treatment rinsing and alkaline treatment rinsing generating the most
wastewater of the MP&M unit operations. In addition to these unit operations,
Table 5-2 lists additional, less common unit operations identified from MP&M DCPs.
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5.0 INDUSTRY DESCRIPTION
Descriptions of these operations are contained in the administrative record for this
rulemaking.
1. Abrasive Blasting is the removal of surface films from a part by using
abrasive particles pneumatically impinged against the part.
The abrasive particles used include glass or plastic beads, sand, metal shot,
grit (crushed metal shot), slag, silica, pumice, or other materials such as
walnut shells. Most abrasive blasting operations are dry; however, wet
blasting is used where a slurry of fine abrasive is suspended in a liquid. In
some cases, oil is used as the liquid carrier (e.g., manufacture of spark
plugs), but the most commonly used liquid carrier is water. Water carriers
sometimes contain rust inhibitors, wetting agents, or other additives. The
wet process is usually operated in a cabinet, horizontal-plane turntable or
similar equipment, or belt conveyor.
The primary applications of wet abrasive blasting include: removing burrs
on precision parts; producing satin or matte finishes; removing fine tool
marks; and removing light mill scale, surface oxide, or welding scale. Wet
blasting can be used to finish fragile items such as electronic components.
Also, some aluminum parts are wet blasted to achieve a fine-grained matte
finish for decorative purposes. During abrasive blasting operations, the
water and abrasive are typically reused until the particle size diminishes
due to impacting and fracture.
The abrasive blasting process generates wastewater when spent abrasive
and water are replaced. A rinse can follow abrasive blasting to remove
abrasive and liquid carrier from the parts.
2. Abrasive Jet Machining is a process in which a controlled stream of
abrasive-bearing fluid is directed at a part for the purpose of cutting or
metal removal. This process is typically used on hard metal substrates and
polymer composites.
In this process, the media is fed from a reservoir into a high-pressure gas
or liquid stream (500 to 3,000 feet per second), which propels the particles
with explosive force. Abrasive jet machining is used to remove metal
oxides, deburring, drilling, and cutting thin sections of metal. Process
water is used as a carrier of the abrasive media. The liquid streams are
typically alkaline or emulsified oil solutions.
This process generates wastewater through solution dumps. A rinse
sometimes follows the process to remove abrasive material and liquid
carrier from the parts.
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5.0 INDUSTRY DESCRIPTION
3. Acid Treatment is the application of a solution of an inorganic (mineral)
acid, organic acid, or acid salt, sometimes in combination with a wetting
agent or detergent, to remove oil, dirt, heat treating scale, metals, or oxide
from metal surfaces.
Acid treatment is performed with various acid concentrations and is
referred to as cleaning, pickling, acid dipping, acid etching, bright dipping,
descaling, or desmutting. Common mineral acids used include sulfuric,
hydrochloric, nitric, hydrofluoric, and chromic acids. Common organic
acids used include citric, tartaric, acetic, oxalic, and gluconic acids. Sodium
bisulfate and sodium pyrophosphate are commonly used acid salts.
Some acid treatment operations generate hexavalent chromium-bearing
wastewater from the use of chromic acid. Chromic acid is used
occasionally for cleaning cast iron and stainless steel, bright dipping of
copper and copper alloys, pickling of cadmium, and cleaning of aluminum.
Also, chromic acid solutions can be used as final steps in acid cleaning-
phosphate conversion coating systems.
The acid treatment solution may or may not be heated. Acid treatment is
performed as an immersion or spray operation. Complex shapes can
require agitation with immersion or spray treatment. Acid treatment
operations often follow alkaline cleaning prior to electroplating.
It should be noted that the acid treatment unit operation does not include
all processes conducted in acid solutions. For example, conversion coatings
performed in acid solutions are not considered part of the acid treatment
unit operation. Additional examples include anodizing, electroplating, and
chemical milling. The key distinguishing factors between these operations
and acid treatment operations are the bath chemistries and the function of
the process. These factors are discussed in the following paragraphs.
Acid cleaning can be distinguished from phosphate conversion coating
(phosphating), which is a chemical conversion coating process (unit
operation 12). In some instances, the use of phosphoric acid cleaning
imparts a thin phosphate coating; however, the primary purpose of
phosphoric acid cleaning is to clean and mildly etch the part's surface. The
phosphating process is usually applied to parts prior to painting. Cleaning
baths are typically formulated with at least 15% phosphoric acid and a
water-soluble solvent, whereas phosphating baths contain only about
5% phosphoric acid and no solvent. Salts of magnesium and zinc are
typically added to phosphating baths, but not to cleaning baths. It is
common practice to measure weight gain of parts through some
phosphating baths.
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5.0 INDUSTRY DESCRIPTION
Some chemical conversion coatings (see unit operation 12) are formulated
with chromic acid. These coatings are most often applied to aluminum,
cadmium, and zinc basis metals and deposits. These processes are
different from chromic acid treatment because they impart a complex
metal film on the part surface to improve corrosion resistance and/or
provide a good base for paint adhesion. In contrast, chromic acid cleaning
removes surface oxides and other corrosion products.
Chemical machining (see unit operation 13) can be distinguished from acid
etching. During chemical machining, acid solutions are used to machine
metal alloys, removing a significant amount of metal from the part. In
contrast, acid etching is used to clean surfaces or prepare them for
subsequent finishing operations. For example, acid etching is commonly
used prior to electroplating of ferrous alloys to activate the surface of the
part (i.e., remove trace oxide deposits) and ensure uniform plating layer
deposition.
Anodizing (unit operation 6) is performed with acid solutions that are
similar to some acid treatment processes. Anodizing, which is applied
primarily to aluminum parts, is performed using an electrolytic current to
form an oxide coating on the part's surface. Acid treatment is also used
for aluminum parts, but as a nonelectrolytic immersion process.
Wastewaters generated from acid treatment include spent solutions and
rinsewaters. During use, the acid content of the process solution is
diminished through reactions with metal and impurities present on the
parts being processed. Spent solutions are typically batch dumped and
treated or disposed of off site. In some cases, spent acid solutions are used
as treatment chemicals to adjust the pH of other MP&M wastewater.
Most acid treatment operations, including chromic acid treatment, are
followed by a rinse to remove residual acid. Acid treatment rinsewaters
are typically discharged to treatment or reused in other rinse tanks.
Adhesive Bonding is the joining of two or more pieces of material by
applying thermoset, thermoplastic, or chemically reactive cure adhesive to
the contact surfaces.
Adhesive bonding is typically a dry operation, although, in some cases,
contact cooling water is used.
Alkaline Treatment is the nonelectrolytic application of alkaline solution to
a metal surface for the purpose of cleaning, degreasing, or chemical
etching.
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Alkaline cleaning and degreasing are performed to remove oily dirt or
solid soils from parts. These processes are commonly applied after parts
have been processed in unit operations that use oil and grease (e.g.,
machining) and prior to finishing operations, such as electroplating. Most
alkaline cleaning and degreasing solutions include three major types of
constituents: (1) builders, such as alkali hydroxides and carbonates, which
are the source of alkalinity in the cleaner; (2) organic or inorganic
additives, which promote better cleaning or affect the metal surface in
some way; and (3) surfactants. Sodium cyanide is also used in some
cleaning formulations as a complexing agent and/or to prevent staining of
brass and copper work; however, its use has diminished because of
environmental concerns with cyanide. Alkaline cleaners are typically
heated and applied by immersion or spray methods. Immersion operations
sometimes include mechanical action (e.g., stirring, pumping) or ultrasonic
agitation.
Emulsion cleaning is an alkaline treatment (typically performed in the pH
range of 7 to 9) that uses common organic solvents (e.g., kerosene, mineral
oil, glycols, and benzene) dispersed into water with the aid of an
emulsifying agent. Depending on the solvent used, cleaning is performed
at temperatures from room temperature to 82 °C (180°F). The process is
often used as a replacement for vapor degreasing. Rinsing normally
follows emulsion cleaning.
Alkaline etching is an alkaline treatment process usually associated with
aluminum finishing. This process is typically performed by immersing parts
for one to three minutes in a hot solution containing alkalis such as sodium
hydroxide. Alkaline etching removes a thin surface layer and is used to
eliminate scratches, nicks, and other surface imperfections. Common
etching depths range from 3 to 20 micrometers (/xm). Alkaline etching is
typically preceded by a nonetching aluminum cleaning and rinsing, and
followed by a thorough rinsing and usually desmutting. Smut (copper, iron,
or other aluminum alloy constituents that are not soluble in sodium
hydroxide) forms on the surface of the part during etching.
Wastewaters generated from alkaline treatment include spent solutions and
rinsewaters. Alkaline treatment solutions become contaminated during use
from the introduction of soils and/or dissolution of the base metal, and
they are typically batch dumped for treatment or disposal. Alkaline
treatment operations are typically followed by a water rinse that is
discharged to treatment.
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6. Anodizing is an electrolytic oxidation process which converts the surface of
the metal to an insoluble oxide. These oxide coatings increase surface
wear resistance, improve corrosion protection, provide decorative finishes,
provide a base for painting and other coating processes, and provide
special electrical properties.
Aluminum is the most frequently anodized material, while magnesium is
also commonly anodized. Common aluminum anodizing processes are
performed using chromic, sulfuric, boric/sulfuric, or other acid solution
chemistries. Anodized coatings are typically considered either decorative
or "hard". Hard anodizing is used when mechanical properties such as
hardness or wear resistance are required.
Most anodizing involves immersing racked parts in tanks, although
continuous anodizing is performed on coils of aluminum. For aluminum
parts, the oxide is formed when the parts are anodically polarized in acid
solutions. The oxide layer begins forming on the surface, and, as the
reaction proceeds, the oxide layer thickens as more metal is oxidized.
The sulfuric acid process is widely used for aluminum alloys except for
parts subject to stress or containing recesses in which the sulfuric acid
solution can collect and attack the aluminum. Chromic acid anodic
coatings have a relatively thick boundary layer and are more protective
than sulfuric acid coatings. For these reasons, chromic acid can be used if
the part cannot be completely rinsed. Conventional chromic and sulfuric
acid anodized coatings range in thickness from 2.5 to 25 pm. Hard
anodized coatings, which are applied using higher unit amperages and
reduced temperatures, range in thickness from 25 to 300 pm. Hard
coatings are used for parts requiring higher resistance to wear, erosion, and
corrosion.
Many parts are colored after anodizing. Anodizing coloring can be
accomplished in several ways, but the most common method is organic
dyeing. Other methods include electrolytic coloring and precipitation
pigmentation. When applicable, anodizing coloring is performed prior to
sealing.
Following anodizing, parts are typically rinsed, then proceed through a
sealing operation that improves the corrosion resistance of the coating.
Common sealants include chromic acid, nickel acetate, nickel-cobalt
acetate, sodium dichromate, and hot water. A rinse sometimes follows the
sealing operation.
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Wastewaters generated from anodizing include spent anodizing solutions,
sealants, and rinsewaters. Because of the anodic nature of the process,
anodizing solutions become contaminated with the base metal being
processed. These solutions eventually reach an intolerable concentration of
dissolved metal and require treatment or disposal. Rinsewaters following
anodizing, coloring, and sealing steps are typically discharged to treatment.
Assembly is the fitting together of manufactured parts or components into
a complete part, product, or machine.
Assembly operations are typically dry; however, special circumstances can
require water for cooling or buoyancy. Also, rinsing may be necessary
under some conditions.
Barrel Finishing (also referred to as mass finishing and tumbling) is the
removal of burrs, scale, and oxides by finishing in a rotating barrel or
vibrating unit with an abrasive media, water, and chemical additives.
Barrel finishing obtains a uniformity of surface finish typically not possible
by hand finishing. For large quantities of small parts, barrel finishing is
generally the most economical method of cleaning and surface
conditioning.
Parts to be finished are placed in a rotating barrel or vibrating unit with an
abrasive media (e.g., ceramic chips, pebbles). Water and chemical
additives are sometimes added to assist in the operation. Alkaline
detergents are typically used as chemical additives. As the barrel rotates,
the upper layer of the part slides toward the lower side of the barrel,
causing the burr removal, abrasion, or polishing. Similar results can also
be accomplished in a vibrating unit, where the entire contents of the
container are in constant motion, or in a centrifugal unit, which compacts
the load of media and parts as the unit spins and generates up to 50 times
the force of gravity. Spindle finishing is a similar process, where parts to
be finished are mounted on fixtures and exposed to a rapidly moving
abrasive slurry.
Wastewater generated by barrel finishing includes spent process solutions
and rinses. Following the finishing process, the contents of the barrel are
unloaded. Process wastewater is either discharged continuously during the
process, discharged after finishing, or collected and reused. The parts are
sometimes given a final rinse to remove particles of abrasive media from
part surfaces.
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9. Brazing is a thermal process in which a filler metal with a melting point
lower than that of the base metal is used to form a metallurgical bond.
Bonding results from the intimate contact produced by the dissolution of a
small amount of base metal in the molten filler metal, without fusion of the
base metal. Brazing and soldering operations are similar; the term brazing
is used when the temperature of the filler exceeds 425 °C (800°F).
This process usually does not require process water. However, brazing can
be followed by quenching or cooling in a solution of water or emulsified
oils. A rinse step may also be included, especially after an oil quench.
The quenching/cooling water and rinse water are typically discharged after
they accumulate contaminants.
10. Burnishing is the sizing or finishing of a part (previously machined or
ground) by displacing, rather than removing, minute surface irregularities.
Burnishing is accomplished with a smooth point or line-contact and with
fixed or rotating tools.
Lubricants or soap solutions can be used to cool tools used in burnishing
operations. Wastewater is generated from burnishing operations through
process solution dumps and rinsing.
11. Calibration is the application of thermal, electrical, or mechanical energy
to set or establish reference points, often in comparison to standards, for a
component or complete assembly.
Calibration is typically a dry unit operation. However, a limited number of
applications can require process water (e.g., calibration of pumps or flow
meters).
12. Chemical Conversion Coating is the process of forming a protective coating
on the surface of a metal. Chemical conversion coating includes chromate
conversion coating (chromating), phosphate conversion coating
(phosphating), metal coloring, and passivating.
These coatings are applied to previously deposited metal or base metal to
increase corrosion-protection and lubricity, prepare the surface for
additional coatings, or create a specific surface appearance.
In chromate conversion coating, metals are coated with solutions of
hexavalent chromium and other compounds by chemical treatment.
Chromate conversion coatings may be used as a "stand-alone" surface
preparation or as a part of a multi-stage plating or finishing operation.
Many aluminum alloys are treated with a chromate conversion coating as a
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5.0 INDUSTRY DESCRIPTION
precursor to organic coating. Plating layers such as zinc or cadmium are
frequently treated with a chromate conversion coating to generate a more
passive, corrosion resistant film. Most chromate coatings are applied
through chemical immersion, although spray or brush application can be
used. Variations in process solution formulation can impart a range of
colors to the coatings, including colorless, iridescent yellow, brass, brown,
and olive drab. Following chromating, parts are rinsed to prevent further
surface reactions between the chromating solution and the base metal.
Phosphate conversion coatings are applied for one or more of the
following reasons: to provide a base for paints and other organic coatings;
to condition surfaces for cold forming operations by providing a base for
drawing compounds and lubricants; to impart corrosion resistance to the
metal surface by the coating itself; or to provide a suitable base for
corrosion-resistant oils or waxes. Phosphate conversion coatings are
formed by immersing parts in a dilute solution that can contain phosphoric
acid, phosphate salts, accelerators, and other chemicals. Metal types
processed in this operation typically include iron, steel, aluminum, zinc-
plated steel and zinc/aluminum alloy-plated steel. The method of applying
the phosphate coating depends on the size and shape of the part to be
coated. Small parts can be coated in barrels immersed in the phosphating
solution. Large parts, such as steel sheet and strip, are spray coated or
passed continuously through the phosphating solution. Most phosphated
parts that are to be painted are given a post-treatment seal. The post-
treatments vary from simple chromic acid solutions to complex proprietary
formulations that do not contain chromium. A deionized water rinse is
typically used after post-treatment.
Metal coloring by chemical conversion coating produces a large group of
decorative finishes. Metal coloring includes the formation of oxide
conversion coatings. In this operation, the metal surface is converted into
an oxide or similar metallic compound, giving the part the desired color.
The most common colored finishes are used on copper, steel, zinc, and
cadmium. Metal coloring treatments include antiquing, bluing, blackening,
and other processes. For example, black oxide is a finish used on steel
parts to provide an attractive appearance and to offer improved corrosion
resistance. Usually, the black oxide process follows heat treating. Parts
are placed in a heated bath (285 °F), typically formulated with 80 ounces
per gallon of sodium hydroxide and sodium or potassium nitrate; sodium
dichromate is also used in some bath formations. Proprietary baths are
also available. Following black oxide treatment, the parts are usually
rinsed and sealed. Various sealants are used (e.g., light oil and dry-to-
touch sealant). The primary purpose of these sealants is to protect the
surface from atmospheric humidity.
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Passivation forms a protective film on metals, particularly stainless steel
and copper, by immersing parts in an acid solution. Stainless steel is
passivated to dissolve embedded iron particles and to form a thin oxide
film on the surface of the metal. Typical solutions for passivating stainless
steel include nitric acid and nitric acid with sodium dichromate. Copper is
passivated with a solution of ammonium sulfate and copper sulfate,
forming a blue-green patina on the surface of the metal that reduces the
reactivity of the surface. Rinsing is typically required after passivation,
especially for parts with recessed surfaces that can retain process solution.
Wastewater generated by chemical conversion coating operations includes
spent process solutions and rinses. Discarded process solutions include
both the chemical conversion coating solutions and post-treatment sealant
solutions. These solutions are commonly discharged when contaminated
with the base metal or other impurities. Also, chromium-based solutions,
which are typically formulated with hexavalent chromium, lose operating
strength when the hexavalent chromium reduces to trivalent chromium
during use. Rinsing normally follows each process step, except after some
sealants, which dry on the part surface.
13. Chemical Machining (chemical milling) is the controlled dissolution and
removal of a metal with chemical reagents or etchants to produce specific
design configurations or tolerances.
Chemical machining is typically performed by applying a masking agent to
cover a portion of the part's surface, then treating the exposed (unmasked)
surface with the chemical machining solution.
Chemical machining and chemical etching (either acid or alkaline etching)
are similar processes, except the rates and depths of metal removal are
usually much greater in chemical machining. Typical solutions for chemical
machining and etching include sodium hydroxide, ferric chloride, nitric
acid, ammonium persulfate, chromic acid, cupric chloride, hydrochloric
acid, and combinations of these reagents. Chemical machining of
aluminum is a common process used in the aerospace industry for
structural components, and is usually performed using a concentrated
sodium hydroxide solution.
Wastewater generated by chemical machining operations includes spent
process solutions and rinses. Process solutions are commonly discharged
after becoming contaminated with the base metal. Rinsing normally
follows chemical machining.
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14. Corrosion Preventive Coating is the application of compounds to metal
surfaces to create barrier films that protect against corrosion.
Many corrosion preventive materials are also formulated to function as
lubricants or as a base for paint. Typical applications include assembled
machinery or equipment in standby storage; finished parts in stock or spare
parts for replacement; tools such as drills, taps, dies, and gauges; and mill
products such as sheet, strip, rod, and bar.
Corrosion preventive coating compounds are applied by spraying, dipping,
brushing, or wiping, depending on the type of compound used and the
configuration of the part.
Corrosion preventive coatings can be divided into seven general categories:
petrolatum compounds, oil compounds, hard dry-film compounds, solvent-
cutback petroleum-based compounds, emulsion compounds, water-
displacing polar compounds, and fingerprint removers and neutralizers.
Emulsion compounds are the primary types in which process water is used.
Emulsion compounds are oil-in-water emulsions containing 8 to 12% oil.
They are typically purchased as concentrates and diluted with water at
ratios of 1 part concentrate to 4-10 parts water. In some instances, these
compounds are used in power washers.
Wastewater generated from corrosion preventive coating operations
includes spent process solutions and rinses. Process solutions are
discharged when they become contaminated with impurities or are depleted
of constituents. Corrosion preventative coatings are not typically followed
by an associated rinse, but rinsing is sometimes performed to remove the
coating before further processing.
15. Disassembly is the process of systematically removing components from a
vehicle, machine, or other product, typically for the purpose of inspection,
testing, maintenance, or rebuilding.
Disassembly is typically a dry operation. However, cleaning or rinsing
procedures are sometimes integrated into the disassembly process.
16. Electrical Discharge Machining (EDM), also known as spark machining or
electronic erosion, is a process that removes metal from a part by the
formation of an electrical spark between an electrode, shaped to the
required contour, and the part.
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This operation is performed primarily for machining carbides, hard
nonferrous alloys, and other hard-to-machine materials. The EDM cutting
tool can be made from a soft, easily worked material such as brass, because
the tool has no direct contact with the part. The tool works in conjunction
with a fluid, which is fed to the part under pressure. The fluid serves as a
dielectric, washing particles of eroded metal from the part or tool and
maintaining a uniform resistance to the current flow. Common fluids used
in the process include air, petroleum oils, kerosene, silicone oils, deionized
water, polar liquids, and aqueous ethylene glycol solutions.
The majority of electrical discharge machining processes are operated dry.
In some cases, water is used in the process, and wastewater is generated by
the discharge of water-based dielectric fluids.
17. Electrochemical Machining is the controlled electrolytic removal of metal
from a part by maintaining the part in close proximity to a shaped tool. In
this process, the metal part is the anode, the formed tool is the cathode,
and the applied potential causes a selective dissolution of metal from the
part. By controlling the current distribution, metal is removed from the
part only in those areas directly adjacent to the cathode tool.
Since the surface finish of the electrode tool will be reproduced in the
surface of the part, electrode shape and size tolerances are important.
While copper is frequently used as the electrode, brass, graphite, and
copper-tungsten are also used. The tool must be an electrical conductor,
easy to machine, corrosion resistant, and able to conduct the quantity of
current needed. Various electrolytes are used, including sodium chloride,
sulfur dioxide, ammonia, and hydrocyanic acid solutions.
Wastewater generated by electrochemical machining includes spent
electrolytes and rinses.
18. Electrolytic Cleaning is the removal of soil, scale, or surface oxide from a
metal part using an aqueous solution and electric current. The electrolyte
is typically alkaline; however, electrolytic acid cleaning is also performed.
Electrolytic alkaline cleaning produces a cleaner surface than
nonelectrolytic methods of alkaline cleaning. This method uses strong
agitation, gas evolution in the solution, and oxidation-reduction reactions
that occur during electrolysis. In addition, dirt particles become electrically
charged and are repelled from the part surface. Some cleaning processes
polarize the parts anodically while other processes polarize the parts
cathodically. During periodic reverse cleaning, parts are alternately
polarized anodically and cathodically. Periodic reverse cleaning improves
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smut removal, accelerates cleaning, and results in a more active surface for
subsequent surface finishing operations. Alkaline electrocleaners are
formulated with combinations of alkali (usually sodium hydroxide and
sodium carbonate), wetting agents, soaps, and chelators. Sodium cyanide is
sometimes used in electrolytic cleaning formulations as a chelating agent
and/or to prevent staining of brass and copper parts; however, its use has
diminished due to environmental concerns.
Electrolytic acid cleaners are sometimes used as a final cleaner before
electroplating. Sulfuric acid is most frequently used as the electrolyte. As
with electrolytic alkaline cleaning, the effectiveness of the process is
enhanced by the mechanical scrubbing effect caused by cathodic gas
generation at the part/solution interface. Time cycles are typically less
than two minutes.
Wastewater generated from electrolytic cleaning operations includes spent
process solutions and rinses. Electrolytic cleaning solutions become
contaminated during use due to dissolving of the base metal and the
introduction of contaminants. As the performance of the solution
diminishes, it is typically batch dumped for treatment or disposal. Process
solution disposal can be required frequently (e.g., weekly) for high-
production operations. Following electrolytic cleaning, thorough rinsing is
used to remove residual cleaner and prevent the contamination of
subsequent process baths.
19. Electroplating is the application of a thin surface coating of one metal
upon another by electrodeposition. Electroplating is performed to provide
corrosion protection, wear or erosion resistance, antifrictional
characteristics, electrical conductivity, or decoration.
In electroplating, metal ions in acid, alkaline, or neutral solutions are
reduced on the cathodic surfaces of the parts being plated. The metal ions
in solution are typically replenished by dissolving metal from anodes
contained in inert wire or metal baskets. Replenishment with metal salts
or oxides is also practiced, especially for chromium electroplating
(chromium trioxide is often added as a source of chromium). In addition
to water and the metal being deposited, electroplating solutions often
contain agents that form complexes with the metal being deposited,
stabilizers to prevent hydrolysis, buffers for pH control, catalysts to assist in
deposition, chemical aids for dissolving anodes, and miscellaneous
ingredients that modify the process to attain specific properties. Cyanide,
usually in the form of sodium or potassium cyanide, is frequently used as a
complexing agent for zinc, cadmium, copper, and precious metal baths.
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Metal parts can be electroplated in barrels, on racks, or continuously from
a spool coil. Electroplating processes are operated both manually and
automatically. Automated electroplating machines are used mostly for
high-production items. Parts are typically cleaned prior to electroplating
using alkaline and acid solutions. Following electroplating, post-
electroplating processes, such as sealing and conversion coating, can be
used.
Between the different process steps, the parts and fixtures are rinsed. This
reduces the carry-over of process chemicals that would otherwise
contaminate subsequent process solutions. Following electroplating
processes, rinses are sometimes used to capture drag-out for treatment or
recovery. A common application of drag-out rinsing is following chromium
electroplating. Drag-out rinses are also used with nonchromium
electroplating processes, such as nickel chloride or copper cyanide
electroplating. Overflow rinses are sometimes used following drag-out
rinsing as a secondary rinsing step.
Wastewater generated from electroplating operations includes spent
process solutions and rinses. Electroplating solutions occasionally become
contaminated during use due to dissolution of the base metal and/or the
introduction of other contaminants. As this happens, the performance of
the electroplating solutions diminishes. Spent concentrated solutions are
typically treated for contaminant removal and reused, processed in a
wastewater treatment system, or sent off site for disposal. Rinsewaters,
including some drag-out rinse tank solutions, are typically treated on site.
20. Electron Beam Machining is the removal of material from a metal part by
a high-energy electron beam. At the point where the energy of the
electrons is focused, sufficient thermal energy is generated to vaporize the
metal substrate.
Electron beam machining is typically carried out in a vacuum. While the
metal-removal rate of electron beam machining is approximately
0.01 milligrams per second, the process is accurate and is especially
adapted for micromachining. There is a minimal heat-affected zone and
no pressure is applied to the part, allowing close tolerances to be
maintained. The process results in X-ray emissions, which requires that the
work area be shielded to absorb radiation. At present, the process is used
for drilling holes as small as 0.0508 mm (0.002 in.), cutting slots, and
shaping small parts.
Electron beam machining is a dry process; however, some operations can
discharge wastewater as a result of quenching.
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21. Electropolishing is the process of smoothing a metal using an electrolyte
and a direct current. Electropolishing is a reverse electrodeposition
operation that is performed anodically (the part being polished is the
anode) in a concentrated acid or alkaline solution. When current is
applied, a polarized film forms on the metal surface, through which metal
ions diffuse. In this process, areas of surface roughness on parts serve as
high-current density areas and are dissolved at rates greater than the lower
portions of the metal surface.
During electropolishing, metal removal is usually limited to 2.5 to 65 /xm.
Metals are electropolished to improve appearance, reflectivity, and
corrosion resistance. Base metals processed by electropolishing include
aluminum, copper and copper alloys, zinc, low-alloy steel, and stainless
steel. Common electrolytes include sodium hydroxide and combinations of
sulfuric acid, phosphoric acid, and chromic acid.
Wastewater generated from electropolishing operations includes spent
process solutions and rinses. Electropolishing generates metal ions that
build up over time in the process solution. Eventually, the concentration of
dissolved metals increases beyond tolerable levels and the process becomes
ineffective. Typically, a portion of the bath is decanted and some fresh
chemicals are added, or the entire solution is discharged and replaced with
fresh constituent chemicals. Concentrated solutions are typically processed
in a wastewater treatment system or sent off site for disposal. Rinsing is
critical to removal of the corrosive film of drag-out remaining on the parts.
Rinsing can involve several steps and include hot immersion or spray
rinses. Wastewaters from rinsing are typically treated on site.
22. Floor Cleaning is the removal of dirt, debris, process solution spills, etc.
from process area floors.
Floor cleaning can be performed wet or dry, and includes techniques such
as vacuum cleaning, machine scrubbing, dry sweeping, hose rinsing, and
mopping.
Wastewater is generated during floor cleaning when spilled solutions are
encountered or when water is used to clean the floor. Wastewater from
floor cleaning is typically treated on site or discharged to a POTW.
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23. Grinding is the removal of stock from a part using a tool consisting of
abrasive grains held by a rigid or semi-rigid binder.
The grinding tool is usually in the form of a disk (the basic shape of
grinding wheels), but can also be in the form of a cylinder, ring, cup, stick,
strip, or belt. The most common grinding tool abrasives are aluminum
oxide, silicon carbide, and diamond. Typically, the process involves using a
grinding fluid that cools the tool and part, and removes debris or metal
fines.
Metal working fluids used in grinding operations are similar to those used
for machining. These metal working fluids are used primarily for cooling
and lubricating metal surfaces during grinding operations. The most
common grinding fluid is water-soluble oil coolant (typically prepared by
mixing a concentrate with water in a 1:30 ratio to produce a working fluid
with a 98% water content). The fluid is contained in a reservoir that is
integrated with the grinder or in a separate tank or sump. The fluid is
circulated over the working surface and returned to the sump. After
grinding, parts are sometimes rinsed to remove coolant and debris. The
coolant reservoir is sometimes rinsed, and the water is assimilated into the
working fluid.
Wastewater generated from grinding operations includes spent coolants and
rinses. Metal working fluids become spent for a number of reasons,
including increased biological activity (i.e., the fluids become rancid) or
decomposition of the coolant additives. When metal working fluids no
longer meet performance requirements, they are removed from their
reservoirs and treated for reuse or disposal, or disposed of off site.
Rinsewaters are typically assimilated into the working fluid or treated on
site.
24. Heat Treating is the modification of the physical property of a part through
the application of controlled heating and cooling cycles.
Heat treating includes aging, annealing, austempering, austenitizing,
carburizing, cyaniding, malleabilizing, martempering, nitriding, normalizing,
siliconizing, and tempering. Parts are heated in ovens or in molten salt
solutions and then cooled by quenching in aqueous solutions (e.g., brine
solutions), neat oils (pure oils with little or no impurities), oil/water
emulsions, or air. Heat treating is typically a dry operation, but wastewater
can be generated from spent molten salt solutions, quench water, and
rinses. Descriptions of the specific types of heat treating are presented
below.
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Aging is a general term for changes in the properties of certain metals and
alloys that occur at ambient or moderately elevated temperatures after hot
working or heat treatment.
Annealing is a general term for heating a part to and holding at a suitable
temperature followed by controlled cooling. Annealing is used primarily to
soften metals and to simultaneously produce desired changes in
microstructure or other properties.
Austempering is a heat treatment for ferrous alloys in which a part is
quenched from the austenitizing temperature at a sufficient rate to avoid
forming ferrite or pearlite, and then holding the metal at a constant
temperature until transformation to bainite is complete.
Austenitizing is the formation of austenite by heating a ferrous alloy at or
above the temperature necessary for the transformation.
Carburizing is a heat treatment process for ferrous alloys that increases the
hardness of the part surface due to diffusion of carbon into the metal
surface.
Cyaniding is a heat treating or case hardening process in which a metal is
heated in a molten salt bath containing cyanide to cause simultaneous
absorption of carbon and nitrogen at the surface.
Malleabilizing is the annealing of white cast iron so that some or all of the
combined carbon is transformed into graphite or, in some instances, so that
part of the carbon is removed completely.
Martempering is the quenching of an austenitized ferrous alloy in a
medium that is at a temperature in the upper part of, or slightly above, the
martensite range, and holding the alloy in the medium until the
temperature throughout the alloy is uniform. The alloy is then allowed to
cool in air through the martensite range.
Nitriding is a hardening process in which a part is placed in contact with a
nitrogenous material, usually ammonia or molten cyanide, to introduce
nitrogen into the surface layer.
Normalizing is the heating of a ferrous alloy to a temperature above the
transformation range and then cooling in air to a temperature substantially
below the transformation range.
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Siliconizing is the diffusion of silicon into solid metal, usually steel, at an
elevated temperature.
Tempering is the reheating of hardened steel or cast iron to decrease
hardness and increase roughness.
25. Hot Dip Coating is the coating of parts by immersion in molten metal bath,
leaving a thin layer of molten metal on the part surface.
In hot dip coating, the molten metal coats the part, and an alloy is formed
at the interface of the two metals. Galvanizing (zinc coating on iron and
steel products) is the most common hot dip coating. It is applied for
corrosion protection on structural steel, reinforcing steel, corrugated pipe,
highway guard rail, and numerous other products. Other hot dip coatings
include aluminum coating of steel, aluminum-zinc alloy coating of steel
sheet and wire, tin coating of steel and cast iron, and lead alloy coating of
steel.
Pre-processing and post-processing steps for this process vary among the
different coatings. Most processes begin with cleaning the metal surface to
remove surface contaminants. Cleaning can include degreasing, pickling,
salt bath treatment, and/or abrasive blasting. Prior to coating, flux is
applied to facilitate and speed the reaction of molten metal with the base
metal. Flux is applied in several different ways, including: as an aqueous
solution in which the part is briefly dipped before immersion in the molten
metal; as a molten fused layer or cover on the top of the molten bath; or
as a paste that is applied to the work surface. Following the application of
molten metal, the parts are air dried and/or quenched. Various quench
baths are used, including water, dilute hydrochloric or citric acid, kerosene,
and oil.
Hot dip coating is typically dry, but wastewater can be generated during the
fluxing or quenching. Wastewaters can include spent flux, quench process
solutions, or associated rinses.
26. Impact Deformation is the application of an impact force to a part such
that the part is permanently deformed or shaped. Impact deformation
operations include coining, forging, heading, high-energy rate forming,
peening, shot peening, and stamping.
Natural and synthetic oils, light greases, and pigmented lubricants are used
in impact deformation operations. Pigmented lubricants include whiting,
lithapone, mica, zinc oxide, molybdenum disulfide, bentonite, flour,
graphite, white lead, and soap-like materials.
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Impact deformation operations are typically dry, but wastewater can be
generated from lubricant discharge and from rinsing operations associated
with the process. Descriptions of the specific types of impact deformation
are presented below.
Coining is a closed-die striking operation, usually performed cold, in which
all surfaces of the work are confined or restrained. Coining results in a
well-defined imprint of the die upon the work.
Forging is the plastic deformation of a metal, usually hot, into desired
shapes by the application of a compressive force, with or without dies.
Heading is the upsetting of wire, rod, or bar stock in dies to form an
expanded area or head.
High energy rate forming (HERF) is a group of special forming processes
in which metal undergoes deformation at high velocity. Explosive forming,
electrohydraulic forming, and electromagnetic forming are the most
common HERF processes.
Peening is the mechanical working of metal by hammer blows or shot
impingement (shot peening).
Stamping is a general term covering almost all press operations, including
blanking, hot or cold forming, drawing, bending, and coining.
27. Laminating is the adhesive bonding of layers of metal, plastic, or wood to
form a part.
Water is not typically used for this operation.
28. Laser Beam Machining is the removal of metal from a part using a highly
focused monochromatic, collimated beam of light.
Laser beam machining is a thermal process in which metal removal is
largely accomplished by evaporation, although some material is removed in
the liquid state at high velocity. Since the metal removal rate can be
precisely controlled, laser beam machining is used for such jobs as drilling
microscopic holes in carbides or diamond wire drawing dies and removing
metal in the balancing of high-speed rotating machinery. Laser machining
creates a small heat-affected zone and can be applied effectively to
nonmetallic or hard materials.
Water is not typically used for this operation.
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29. Machining is the general process of removing stock from a part by forcing
a cutting tool through the part and removing a chip of base material.
Machining operations include boring, broaching, chamfering, cutoff,
drilling, hobbing, milling, planing, reaming, sawing, shaping, shaving,
shearing, slotting, tapping, threading, and turning.
Various types of metal working fluids are used in machining operations, the
choice of which depends on the type of machining being performed and
operator preference. The fluids can be categorized into four groups:
straight oil (neat oils), synthetic, semisynthetic, and water-soluble oil. The
most commonly used metal working fluid is water-soluble oil coolant, which
is prepared by mixing a concentrate with water in a 1:15 to 1:25 ratio to
produce a working fluid with a 90% or greater water content.
Machining operations generate wastewater from the discharge of working
fluid or rinse water. Metal working fluids are periodically discarded
because of reduced performance or development of a rancid odor. In most
cases, the fluids that contain a large percentage of oil are contract hauled
as solid waste for disposal or recovery. Some fluids, particularly those with
high water content, are treated on site as wastewater. Coolant degradation
is caused mainly by contamination with tramp oil and dirt and by bacterial
growth, which can be accelerated by oil contamination. After machining,
parts are sometimes rinsed to remove coolant and metal chips. The
coolant reservoir is sometimes rinsed, and the rinse water is assimilated
into the working fluid.
Descriptions of the specific types of machining are presented below.
Boring is the enlargement of a hole by removing metal with a single or
multiple point cutting tool moving parallel to the axis of rotation of the
work or tool.
Broaching is cutting with a tool that consists of a bar having a single edge
or a series of cutting edges (i.e., teeth) on its surface. The cutting edges of
multiple-tooth, or successive single-tooth, broaches increase in size and/or
change in shape. The broach cuts in a straight line of axial direction when
motion is produced in relation to the part, which can also be rotating. To
shape the required surface contour, the entire cut is made in one or more
passes over the part.
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Chamfering (beveling) is the process of making a sloping surface on the
edge of a metal surface.
Cutoff is the severing or slotting of any material or part, usually with a thin
abrasive wheel.
Drilling is the formation of a hole with a rotary, end-cutting tool having
one or more cutting lips and one or more helical or straight flutes or tubes
for ejecting chips or passing a cutting fluid.
Hobbing is the cutting of gears by use of a tool resembling a worm gear,
having helically spaced cutting teeth. In a single-thread hob, the rows of
teeth advance exactly one pitch as the hob makes one revolution.
Milling is the cutting of a part using a rotary tool with one or more teeth.
The teeth engage the part and remove material as the part moves past the
rotating cutter.
Planing is the production of flat surfaces by linear reciprocal motion of the
part and the table to which it is attached relative to a stationary single-
point cutting tool.
Reaming is the process of forming, sizing, or contouring a previously
formed hole using a rotary cutting tool (reamer) with one or more cutting
elements (teeth).
Sawing is the use of a toothed blade or disc to sever parts or cut contours.
Shaping is the use of single point tools fixed to a ram reciprocated in a
linear motion past the part.
Shearing is the severing or cutting of a part by forcing a sharp edge or
opposed sharp edges into the part, stressing the material to the point of
shear failure and separation.
Slotting is the process of cutting a narrow aperture or groove with a
reciprocating tool, cutter, or broach.
Tapping is the use of a cylindrical cutting tool having two or more
peripheral cutting elements to cut internal threads of a desired size and
form. Tapping is a combination of rotary and axial motion; the leading
end of the tap cuts the thread while the tap is supported by the thread it
produces.
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Threading is the process of cutting external threads on a cylindrical
surface.
Turning is the removal of material by forcing a cutting tool against the
surface of a rotating part.
30. Metal Spraying is the application of a metallic coating to a part by
projecting molten fragments of metal through a cone of flame or an
electric arc onto the part. Metal spraying processes include plasma-arc
spray, inert-atmosphere and low-pressure chamber spray, electric-arc spray,
high-velocity oxy-fuel spray, and flame spray.
Metal spray coatings can be sprayed from rod or wire stock or from
powdered material. The basic process involves feeding the material (e.g.,
wire) into a flame where it is melted. The molten stock is then stripped
from the end of the wire and atomized by a high-velocity stream of
compressed air or other gas which propels the material onto a prepared
substrate or part. Depending on the substrate, bonding occurs due to
mechanical interlock with a roughened surface, localized diffusion and
alloying, and/or Van der Waals forces (i.e., mutual attraction and cohesion
between two surfaces).
Metal spray coatings are used for a wide range of special applications,
including the following: insulating layers in applications, such as induction
heating coils; electromagnetic interference shielding; thermal barriers for
rocket engines; nuclear moderators; films for hot isostatic pressing; and
dimensional restoration of worn parts.
Metal spraying is sometimes performed in front of a "water curtain" (a
circulated water stream used to trap overspray) or a dry filter exhaust hood
which captures the overspray and fumes. With water curtain systems, water
is recirculated from a sump or tank. Wastewater is generated when the
sump or tank is periodically discharged. Metal spraying is not typically
followed by rinsing.
31. Painting is the application of an organic coating to a part.
This operation includes the application of coatings such as paint varnish,
lacquer, shellac, and plastics by processes such as spraying, dipping,
brushing, roll coating, lithographing, and wiping.
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Spray painting, the most common application technique, can be used with
nearly all varieties of paint. The paint can be sprayed manually or
automatically, hot or cold, and it may be atomized with or without
compressed air. Electrostatic painting is a method of spray painting that
applies electrostatically charged paint particles to a part with an opposite
charge, followed by thermal fusing of the paint particles to form a cohesive
paint film. By charging the part differently than the particles, the paint is
attracted to the part surface, resulting in improved coverage.
Another common method of painting is electropainting (i.e.,
electrophoretic painting, electrodeposited epoxy, e-coat, etc.), which
involves coating a part by making it anodic or cathodic in a bath that is an
aqueous emulsion of the coating material. The electrodeposition bath
contains stabilized resin, disperse pigment, surfactants, and sometimes
organic solvents in water. Electropainting is used primarily for primer
coats because it consistently produces a uniform, corrosion resistant
coating. During this process, precleaned parts are immersed into the
coating tank (paint) and electrically polarized. The polarization causes
paint deposition after which the parts are removed from the bath. Parts
then pass through a rinsing system. The typical rinsing procedure
comprises several stages and can include dip and spray rinsing.
Ultrafiltration is commonly used to separate and recover paint solids from
the rinse water and to recycle the water.
Other processes included under this unit operation are printing, silk
screening, and stenciling.
Water is used in painting operations as a solvent (water-borne
formulations), for rinsing, for cleanup, and for water-wash (or curtain) type
spray booths. Paint spray booths typically use most of the water in this unit
operation. Spray booths capture overspray (i.e., paint that misses the
product during application), control the introduction of contaminants to the
workplace and environment, and reduce the likelihood of explosions and
fires. Paint booths are categorized by the method of collecting the
overspray.
The two primary types of paint booths are dry filter and water wash booths.
Dry filter booths use filter media (usually paper or cloth filters) to screen
out the paint solids by pulling prefiltered air through the booth, past the
spraying operation, and through the filter media. Water use with dry filter
units is limited to cleaning painting equipment (e.g., rinsing guns and lines)
when water-borne paints are used. The operation of dry filter units is
essentially dry when solvent-based paints are used. Water-wash booths use
a "water curtain" to capture paint overspray by pulling air containing
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entrained paint overspray through a circulated water stream which "scrubs"
the overspray from the air. Although there are numerous design variations
among water-wash booths, the two primary categories are side draft and
downward draft. The basic difference between the two types is how air is
directed through the system to capture the paint overspray. Side-draft
units are typically used by small manufacturing operations and the
downdraft design is used with large, continuous operations. Water is
periodically added to paint booth reservoirs to compensate for evaporative
losses, and chemicals are periodically added to improve paint sludge
formation. The sump water is periodically discharged, usually during
general system cleaning or maintenance. The discharge rate depends on
various factors, including booth design, paint type, overspray rate, and the
water treatment methods used. The sump water can be treated at the
source (e.g., using filtration, activated carbon adsorption, or centrifugation)
and reused instead of being discharged. Water is also used with water-
wash systems for cleaning painting equipment and the booth.
32. Plating is the application of a metallic coating without using external
electrical energy. This unit operation includes electroless plating,
immersion plating, mechanical plating, and vapor plating.
Electroless plating is a chemical reduction process which depends on the
catalytic reduction of a metallic ion in an aqueous solution containing a
reducing agent, and the subsequent deposition of metal without using an
electrical current. It has found widespread use in industry due to several
unique advantages over conventional electroplating. Electroless plating
provides uniform plating thickness on all areas of the part regardless of the
configuration or geometry of the part. Also, an electroless-plated surface is
dense and virtually nonporous. Copper and nickel electroless plating are
the most common. The basic ingredients in an electroless plating solution
are: (1) a source of metal, usually a salt; (2) a reducing agent to reduce
the metal to its base state; (3) a chelating (or complexing) agent to hold
the metal in solution (so the metal will not plate out indiscriminately); and
(4) various buffers and other chemicals designed to maintain bath stability
and increase bath life.
Immersion plating (displacement or cementation plating) is a chemical
plating process in which a thin metal deposit is obtained by chemically
displacing the base metal. Unlike electroless plating, it is not an
autocatalytic process. In this process, a more noble (i.e., less
electrochemically active) metal in the plating solution deposits onto a less
noble (i.e., more electrochemically active) substrate as the result of
substrate oxidation. A common example of immersion plating is the
deposition of zinc on aluminum (zincating). This coating is often applied
5-34
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5.0 INDUSTRY DESCRIPTION
as a base for chromium plating on aluminum parts. Numerous other
metals can be applied by immersion coating, including brass, bronze,
cadmium, copper, lead, nickel, and precious metals.
Mechanical plating is the deposition of a metallic coating on a part using a
cold welding process in which the plating metal is applied to the surface as
a result of contact with solid metal powder. Metal powder, parts, glass
beads (or other impacting media), water, and chemicals are tumbled
together in a rotary barrel to obtain the desired coating. Coatings from 5
(Jim to 75 fj,m can be deposited. The most common metals used for
coatings are zinc and cadmium and alloys of these metals. Mechanical
plating is subject to the same cleaning and rinsing operations used before
and after electroplating operations.
Vapor plating is the process of decomposition of a metal or compound
upon a heated surface by reduction or decomposition of a volatile
compound at a temperature below the melting point of either the deposit
or the base material. The reduction is accomplished by thermal
dissociation or reaction with the base metal.
Wastewater generated from plating operations includes spent process
solutions and rinses. Plating solutions become contaminated during use
due to dissolving of the base metal, the introduction of other contaminants,
and/or the decomposition of bath constituents. Concentrated solutions are
typically treated to remove contaminants and reused, processed in a
wastewater treatment system, or sent off site for disposal. Rinsing follows
most plating processes to remove residual plating solution and prevent
contamination of subsequent process baths. Rinsewaters are typically
treated on site.
33. Plasma Arc Machining is the process of removing material from or shaping
of a part using a high-velocity jet of high-temperature ionized gas.
In plasma arc machining, a gas (nitrogen, argon, or hydrogen) is passed
through an electric arc, causing the gas to become ionized, and raised to
temperatures exceeding 16,650°C (30,000°F). The relatively narrow
plasma jet melts and displaces the part material in its path. Because
plasma machining does not depend on a chemical reaction between the gas
and the part, and because plasma temperatures are extremely high, the
process can be used on almost any metal, including those that are resistant
to oxygen-fuel gas cutting. The method is used mainly for profile cutting of
stainless steel and aluminum alloys.
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5.0 INDUSTRY DESCRIPTION
Although plasma arc machining is typically a dry process, process water is
used for water injection plasma arc torches. In these cases, a constricted
swirling flow of process water surrounds the cutting arc. This operation
may also be performed immersed in a water bath. In both cases, the
process water is used to stabilize the arc, to cool the part, and to contain
smoke and fumes.
34. Polishing is a mechanical finishing operation in which abrasives are used to
remove surface defects (e.g., scratches, pits, tool marks) from parts.
Polishing is usually performed with either a belt or wheel which is
precoated with an abrasive compound. The base metal being polished and
the desired extent of metal removal dictate the choice of compound.
Lubricants are applied to wheels and belts to extend their life and to
improve surface finish. Wheel lubricants are usually made of animal
tallow, fatty acids, and waxes. Belt lubricants are similar, but are
sometimes applied in liquid form. Some lubricants used for belts and
wheels are water soluble. Following polishing, many parts are buffed to
refine the surface finish. Buffing can produce finishes ranging from
semibright to mirror bright or high luster. Buffing is included in the
polishing unit operation. It is usually performed using a revolving cloth or
sisal buffing wheel which is coated with a suitable compound. Liquid
buffing compounds are used extensively for large-volume production on
semiautomated or automated buffing equipment.
Polishing operations are typically dry, although some operations are
performed with liquid compounds or associated rinses.
35. Pressure Deformation is the application of a force (at a slower rate than
with impact deformation) to permanently deform or shape a part. Pressure
deformation includes bending, crimping, drawing, embossing, flaring,
forming, necking, and rolling.
Natural and synthetic oils, light greases, and pigmented lubricants are used
in pressure deformation operations. Pigmented lubricants include whiting,
lithapone, mica, zinc oxide, molybdenum disulfide, bentonite, flour,
graphite, white lead, and soap-like materials.
Pressure deformation is typically dry, but wastewater is sometimes
generated from the discharge of lubricants or from rinsing operations
associated with the process. Descriptions of the specific type of pressure
deformation are presented below.
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5.0 INDUSTRY DESCRIPTION
Bending is the turning or forcing of a part by a brake press or other device
from a straight or even condition to a curved or angular condition.
Crimping is the forming of relatively small corrugations to: (1) set down
and lock a seam; (2) create an arc in a strip of metal; or (3) reduce an
existing arc or diameter.
Drawing is the reduction of cross-sectional area and the increasing of
length by pulling metal through conical taper dies.
Embossing is the raising of a design in relief against a surface.
Flaring is the forming of an outward acute-angle flange on a tubular part
or the forming of a flange by using the head of a hydraulic press.
Forming is making a change (other than shearing or blanking) in the shape
or contour of a metal part without intentionally altering its thickness.
Necking is the reducing of cross-sectional area of a part in a localized area
by stretching, or the reducing of the diameter of a portion of the length of
a cylindrical shell or tube.
Rolling is the reducing of cross-sectional area of metal stock, or otherwise
shaping metal products, through the use of rotating rollers.
36. Rinsing is the use of water to remove foreign material from the surface of
parts or process equipment. In this definition, rinsing is either not
specifically associated with a specific unit operation or is associated with
multiple unit operations. As such, the rinsing unit operation is different
from rinsing associated with electroplating, plating, cleaning, and other unit
operations described in this section. An example of a rinsing operation is a
central rinse tank that services multiple unit operations, such as machining,
grinding, cleaning, and quenching.
37. Salt Bath Descaling is the removal of surface oxides or scale from a part
by immersion of the part in a molten salt bath or a hot salt solution.
Salt bath descaling solutions can contain molten salts, caustic soda, sodium
hydride, and chemical additives. Molten salt baths are used in a salt bath-
water quench-acid dip sequence to remove oxides from stainless steels and
other corrosion-resistant alloys. In this process, the part is typically
immersed in the molten salt (temperatures range from 400 to 540°C),
quenched with water, and then dipped in acid. Oxidizing, reducing, or
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5.0 INDUSTRY DESCRIPTION
electrolytic salt baths can be used depending upon the oxide to be
removed.
Wastewater generated from salt bath descaling operations includes spent
process solutions, quenches, and rinses.
38. Soldering is a thermal process in which a filler metal with a melting point
lower than that of the base metal is used to form a metallurgical bond.
The metals are bonded by the dissolution of a small amount of base metal
in the molten filler metal, without fusion of the base metal. Soldering and
brazing operations are similar; the term soldering is used where the
temperature range falls below 425°C (SOOT).
Some soldering operations use a flux. Fluxes are aqueous or nonaqueous
material used to dissolve, remove, or prevent the formation of surface
oxides on the part. Fluxes are frequently corrosive and are removed with a
variety of solvents and/or aqueous cleaning solutions.
Except for the use of aqueous fluxes, soldering is typically a dry operation;
however, a quench or rinse sometimes follows soldering to cool the part or
remove excess flux or other foreign material from its surface. Recent
developments in soldering technology have focused on fluxless solders and
fluxes that can be cleaned off with water.
39. Solvent Degreasing removes oils and grease from the surface of a part by
using organic solvents, including aliphatic petroleum (e.g., kerosene,
naphtha), aromatics (e.g., benzene, toluene), oxygenated hydrocarbons (e.g.,
ketones, alcohol, ether), and halogenated hydrocarbons (e.g., 1,1,1-
trichloroethane, trichloroethylene, methylene chloride).
Solvent cleaning can be accomplished in either the liquid or vapor phase.
Solvent vapor degreasing is normally quicker than solvent liquid
degreasing. However, ultrasonic vibration is sometimes used with liquid
solvents to decrease the required immersion time with complex shapes.
Solvent cleaning is often used as a precleaning operation prior to alkaline
cleaning, as a final cleaning of precision parts, or as a surface preparation
for some painting operations. Solvent degreasing operations are typically
not followed by rinsing, although rinsing is performed in some cases.
Some DCP respondents reported performing solvent degreasing operations
using a mixture of an organic solvent and water (see solvent degreasing
results in Tables 5-3 and 5-4). However, for the purpose of this regulation,
the Agency is defining solvent degreasing to preclude the use of water in
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5.0 INDUSTRY DESCRIPTION
this unit operation. The Agency considers these "aqueous degreasing"
operations as emulsion cleaners (discussed under unit operation 5).
40. Sputtering is a vacuum coating process in which a metallic or nonmetallic
part is coated with thin films of metal. The surface to be coated is
bombarded with positive ions in a gas discharge tube, which is evacuated to
a low pressure. The source of ions can be either an ion beam or a plasma
discharge into which the material to be bombarded is immersed.
Sputtering differs from vacuum metalizing (unit operation 46) in that the
sputtering coating material is removed by momentum transfer from a solid
cathode or target rather than being vaporized by a heat source.
Sputtering can be used as either a method of surface etching or coating.
The most widely used process is surface coating using plasma discharge.
This process is used mostly by the electronics industry to manufacture
components such as thin film capacitors, video discs, and piezoelectric
transducers. Other applications include the deposition of hard, protective
coatings on high-speed steel cutting tools.
Sputtering is typically operated as a dry process.
41. Stripping is the removal of metallic or organic coatings from base metals.
Stripping is commonly performed as part of the manufacturing process to
recover parts that have been improperly coated or as a part of
maintenance and rebuilding to restore parts to a usable condition.
Metallic coating stripping most often uses chemical baths, although
mechanical means (e.g., grinding, abrasive blasting) are also used.
Chemical stripping of metals is performed either as an electrolytic or
chemical process, depending on various factors (e.g., type of coating and
base metal, bath chemistry).
Wastewater generated from metallic coating stripping operations includes
process solutions and rinses. These stripping solutions become
contaminated due to dissolution of the base metal. Eventually, the
concentration of dissolved metals increases beyond tolerable levels, and the
stripping process becomes ineffective. Typically, the entire solution is
discharged. Concentrated solutions are usually processed in a wastewater
treatment system or sent off site for disposal. Rinsing is a critical step in
the stripping process, because it is needed to remove the corrosive film
remaining on the parts. Wastewaters from stripping rinses are typically
treated on site.
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5.0 INDUSTRY DESCRIPTION
Organic coatings (including paint) are stripped using thermal, mechanical,
and chemical means. Thermal methods include burn-off ovens, fluidized
beds of sand, and molten salt baths. Mechanical methods include scraping
and abrasive blasting (unit operation number 1). Various abrasive media
are used (e.g., steel shot, sand, plastic media, dry ice) depending on the
base material, paint type, and available equipment. Chemical paint
strippers include alkali solutions, acid solutions, and solvents (e.g., acetone,
methylene chloride).
Wastewater generated from organic coating stripping operations includes
process solutions (limited mostly to chemical paint strippers) and rinses.
42. Testing is the application of thermal, electrical, or mechanical energy to
determine the suitability or functionality of a base metal, coating,
component, or complete assembly.
Testing is usually performed to replicate some aspect of the working
environment. Testing is often performed in accordance with standard
procedures, such as those published by the American Society for Testing
and Materials (ASTM), German Industrial Standards (DIN), and the
International Standardization Organization (ISO).
Testing sometimes involves the use of process solutions. Examples of "wet
tests" include dye penetrant testing, hydraulic testing, magnetic flux testing,
and salt spray testing. Some of these tests can also include rinses. Other
types of tests frequently performed, which are typically dry but may
generate wastewater under certain circumstances, include electrical testing,
performance testing, X-ray testing, and ultrasonic testing.
Wastewater generated from testing operations includes spent process
solutions and rinses.
43. Thermal Cutting is the cutting, slotting, or piercing of a part using an
oxyacetylene oxygen lance or an electric arc cutting tool.
Thermal cutting is typically a dry process, except for the use of contact
cooling waters and rinses.
44. Thermal Infusion is the application of a fused zinc, cadmium, or other
metal coating to a ferrous part by infusing the surface of the part with
metal powder or dust in the presence of heat. In this operation, a high-
temperature fusion agent, such as nickel or iron-based metal with a small
amount of boron or silicon, is deposited on the base metal and
subsequently fused to the surface.
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5.0 INDUSTRY DESCRIPTION
Wastewater is not typically discharged from this operation.
45. Ultrasonic Machining is a mechanical process designed to effectively
machine hard, brittle materials. This process removes material using
abrasive grains. The grains are carried in a liquid between the tool and
the part and bombard the work surface at high velocity. This action
gradually chips away minute particles of material in a pattern controlled by
the tool shape and contour. A transducer causes an attached tool to
oscillate linearly at a frequency of 20,000 to 30,000 times per second at an
amplitude of 0.0254 to 0.127 millimeters (0.001 to 0.005 inches). The tool
motion is produced as part of a sound wave energy transmission line which
causes the tool material to change its normal length by contraction and
expansion. The tool holder is threaded to the transducer and oscillates
linearly at ultrasonic frequencies, driving the grit particles into the part.
The cutting particles, boron carbide and similar materials, are of a 280-
mesh size or finer, depending upon the accuracy and the finish desired.
Ultrasonic machining operations include drilling, tapping, coiling, and the
making of openings in all types of dies.
Ultrasonic machining is used principally for machining materials such as
carbides, tool steels, ceramics, glass, gem stones, and synthetic crystals, and
is typically a dry process.
46. Vacuum Metalizing is the coating of a part with metal by flash heating
metal vapor in a high-vacuum chamber containing the part. In this process,
which is carried out at pressures of less than 10"4 to 10"5 torr, the vapor
condenses on all exposed surfaces.
Aluminum deposits comprise about 90% of the volume of vacuum
metalizing. Other metals used include cadmium, chromium, copper, gold,
selenium, silver, and titanium. Both decorative and functional coatings are
applied by this method. Decorative coatings are widely used in the
automotive (e.g., rearview mirrors), home appliance, and costume jewelry
industries. Functional applications include deposits for electrical
components and corrosion protection.
Vacuum metalizing is typically a dry process.
47. Welding is the joining of two or more pieces of material by applying heat,
pressure, or both, with or without filler material, to produce a localized
union through substrate metal fusion. Included in this process are arc
welding, cold welding, electron beam welding, gas welding, laser beam
welding, and resistance welding.
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5.0 INDUSTRY DESCRIPTION
Welding is typically a dry process, except for the occasional use of cooling
or rinsewaters. Descriptions of the specific types of welding are presented
below.
Arc welding fuses metals together by heating them with an arc, with or
without the application of pressure, and with or without the use of filler
metal.
Cold welding is a solid-state welding process in which pressure is used at
room temperature to coalesce metals with substantial deformation at the
weld.
Electron beam welding coalesces metals with the heat obtained from a
concentrated beam composed primarily of high-energy electrons impinging
upon the surfaces to be joined.
Gas welding (oxyfuel gas welding) fuses metals together by heating them
with gas flames. The flames result from combustion of a specific fuel gas
such as acetylene, hydrogen, natural gas, or propane. The process can be
used with or without the application of pressure to the joint, and with or
without adding any filler material.
Laser beam welding joins metal parts using the heat obtained by directing
a beam from a laser onto the weld joint.
Resistance welding is welding with resistance heating and pressure. In this
process, the electric current flows through and heats the part.
48. Wet Air Pollution Control is the process of removing chemicals, fumes, or
dusts that are entrained in air streams exhausted from process tanks or
production areas using process water.
Most frequently, wet air pollution control devices are applied to
electroplating, cleaning, and coating processes. Two common devices
include the wet packed scrubber and the composite mesh pad mist
eliminator.
The wet packed scrubber consists of a spray chamber filled with packing
material. Water is continuously sprayed onto the packing and the air
stream is pulled through the packing by a fan. Contaminants in the air
stream are absorbed by the water spray and the air is released to the
atmosphere. A single scrubber often serves numerous process tanks;
however, the air streams are typically segregated by source into chromium,
cyanide, and acid/alkaline sources. The water is recirculated in the
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5.0 INDUSTRY DESCRIPTION
scrubber until it reaches a moderate dissolved solids concentration. A
blow-down then occurs, where a portion of the scrubber water is discharged
to treatment and replaced with fresh water. The spent scrubber water is
usually segregated into chromium, cyanide, and acid/alkaline sources.
When scrubbers are applied to cleaning and solvent degreasing operations,
the spent scrubber water can contain organics.
Composite mesh pads are most frequently used to control the emissions
from hard chromium electroplating and chromic acid anodizing. The
composite mesh pad mist eliminator removes chromic acid from the
airstream by slowing the velocity of the air and causing the entrained
chromic acid droplets to impinge onto fiber pads. The pads are
periodically washed with a small volume of water and the chromium-
bearing solution is returned to the bath or discharged to treatment.
5.11 Production-Normalizing Parameters and Production-Normalized Flows
To evaluate the volume of water discharged and the mass of pollutants generated by
each MP&M unit operation, EPA used a production-based approach. The Agency
calculated production-normalized flow rates (i.e., the volume of wastewater discharged
per unit of production) and production-normalized pollutant loadings (i.e., the mass of
pollutants generated per unit of production) for each MP&M unit operation and
associated rinse. EPA used a production-based approach to evaluate water discharge
and pollutant loadings because pollutant loadings and wastewater discharge flow rates
depend on the amount of production processed through the unit operation or rinse. The
selection of production-normalizing parameters (PNPs) and the calculation of
production-normalized flow rates (PNFs) are discussed below. The calculation of
production-normalized pollutant loadings and industry pollutant estimates are discussed
in Section 13.0.
Production-normalizing parameters are production units (e.g., mass of raw material
processed) used to normalize the volume of wastewater discharged and mass of pollutant
generated by a unit operation. Because production through a unit operation varies
across sites in the MP&M Phase I industry, production-normalizing parameters were
identified for each unit operation to allow EPA to compare water use characteristics
across sites with varying productions.
The Agency considered the following as potential PNPs for MP&M unit operations:
surface area of parts processed, mass of parts processed, mass of metal removed while
processing parts, mass of material applied while processing parts, volume of material
applied while processing parts, and airflow (standard cubic feet) through air pollution
control equipment (for wet air pollution control unit operations). Table 5-4 presents the
PNP selected for each unit operation. Because most MP&M unit operations involve
treatment of the part's surface, surface area (SA) of parts processed was selected as the
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5.0 INDUSTRY DESCRIPTION
PNP for most unit operations. For unit operations that involve substantial removal of
metal from the part surface (e.g., machining), mass of metal removed (MMR) was
selected as the PNP. For all wet air pollution control operations, airflow (standard cubic
feet, or SCF) through the pollution control device was selected as the PNP.
EPA calculated PNFs for each unit operation based on responses to the DCP. The
PNFs were calculated by dividing the wastewater discharge flow for an operation by the
production in the appropriate PNP units for the operation. Table 5-4 presents the
median production-normalized flow rate for each unit operation, as calculated from DCP
responses.
5-44
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Table 5-1
Typical Unit Operations Performed at MP&M Sites
Unit Operation Name
1. Abrasive Blasting
2. Abrasive Jet Machining
3. Acid Treatment
4. Adhesive Bonding
5. Alkaline Treatment
6. Anodizing
7. Assembly
8. Barrel Finishing
9. Brazing
10. Burnishing
11. Calibration
12. Chemical Conversion Coating
13. Chemical Machining
14. Corrosion Preventive Coating
15. Disassembly
16. Electrical Discharge Machining
17. Electrochemical Machining
18. Electrolytic Cleaning
19. Electroplating
20. Electron Beam Machining
21. Electropolishing
22. Floor Cleaning
23. Grinding
24, Heat Treating
25. Hot Dip Coating
26. Impact Deformation
27. Laminating
28. Laser Beam Machining
29. Machining
30. Metal Spraying
31. Painting
32. Plating
33. Plasma Arc Machining
34. Polishing
35. Pressure Deformation
36. Rinsing
37. Salt Bath Descaling
38. Soldering
39. Solvent Degreasing
40. Sputtering
41. Stripping
42. Testing
43. Thermal Cutting
44. Thermal Infusion
45. Ultrasonic Machining
46. Vacuum Metalizing
47. Welding
48. Wet Air Pollution Control
Source: MP&M Phase I DCP database.
5-45
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Table 5-2
Additional Water-Using Unit Operations Performed at MP&M Sites00
Unit Operation Name
Impregnation
Impregnation-Rinse
Phosphor Deposition
Phosphor Deposition-Rinse
Printed Circuit Board Manufacturing Operations
Printed Circuit Board Manufacturing Operations-Rinse
X-Ray Film-Developing
X-Ray Film-Developing-Rinse
X-Ray Film-Fixer
X-Ray Film-Fixer-Rinse
Phosphate Conversion Coating Pretreatment
Dielectric Coating
Plate Making-Precoat
Plate Making-Developing
Plate Making-Developing Rinse
Galvanizing Pretreatment
Shot Tower-Lead Shot Manufacturing
Masking for Chemical Machining
Metallic Fiber Cloth Manufacturing
Number of DCP Recipients
Performing Unit Operation
5
3
1
1
10
10
5
1
3
2
3
1
1
1
1
1
1
1
1
Source: MP&M Phase I DCP database.
(a)These unit operations were identified based on responses to the January 1991 DCP mailout.
5-46
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Table 5-3
Number of MP&M Phase I Sites Using
and Discharging Process Water by Unit Operation00
Unit Operation
1. Abrasive Blasting
1R. Abrasive Blasting Rinse
2. Abrasive Jet Machining
2R. Abrasive Jet Machining
Rinse
3. Acid Treatment
3R. Acid Treatment Rinse
4. Adhesive Bonding
4R. Adhesive Bonding Rinse
5. Alkaline Treatment
5R. Alkaline Treatment Rinse
6. Anodizing
6R. Anodizing Rinse
7. Assembly
7R. Assembly Rinse
8. Barrel Finishing
8R. Barrel Finishing Rinse
9. Brazing
9R. Brazing Rinse
10. Burnishing
10R. Burnishing Rinse
11. Calibration
11R. Calibration Rinse
12. Chemical Conversion
Coating
12R. Chemical Conversion
Coating Rinse
13. Chemical Machining
13R. Chemical Machining Rinse
Number of
Sites
Performing
Unit Op
4,133
228
894
41
3,546
3,408
2,308
50
4,296
2,680
331
302
6,761
118
3,238
896
2,803
398
1,055
83
1,680
16
3,155
2,792
161
136
Number of
Sites
Performing
Unit Op Wet
196
228
804
41
3,288
3,408
74
50
4,258
2,680
328
302
73
118
2,946
896
32
398
177
83
17
16
3,052
2,792
154
136
Number of
Sites
Generating
Wastewater0"
from Unit Op
196
180
804
0
3,156
3,296
74
0
4,167
2,566
289
281
73
47
2,872
800
0
362
177
62
17
0
2,847
2,467
109
130
Percentage
of Sites
Performing
Unit Op
Wet
5
100
90
100
93
100
3
100
99
100
99
100
1
100
91
100
1
100
17
100
1
100
97
100
95
100
Percentage of
Sites
Generating
Wastewater0"
from Wet OpW)
100
79
100
0
96
97
100
0
98
96
88
93
100
40
97
89
0
91
100
74
100
0
93
88
71
95
'"All data is based on a scale-up of MP&M Phase I DCP information.
""These totals include sites generating process wastewater that is contract-hauled off site.
""Solvent degreasing operations reported as using process water are discussed under emulsion cleaning (see unit operation #5).
(l)This percentage is calculated by dividing the number of sites generating wastewater from the unit operation by the number of sites performing
the operation wet. 5-47
-------
Table 5-3 (Continued)
Number of MP&M Sites Using
and Discharging Process Water by Unit Operation00
Unit Operation
14. Corrosion Preventive
Coating
14R. Corrosion Preventive
Coating Rinse
15. Disassembly
15R. Disassembly Rinse
16. Electrical Discharge
Machining
16R. Electrical Discharge
Machining Rinse
17. Electrochemical Machining
17R. Electrochemical Machining
Rinse
18. Electrolytic Cleaning
18R. Electrolytic Cleaning Rinse
19. Electroplating
19R. Electroplating Rinse
20. Electron Beam Machining
20R. Electron Beam Machining
Rinse
21. Electropolishing
21 R. Electropolishing Rinse
22. Floor Cleaning
22R. Floor Cleaning Rinse
23. Grinding
23R. Grinding Rinse
24. Heat Treating
24R. Heat Treating Rinse
25. Hot Dip Coating
25R. Hot Dip Coating Rinse
26. Impact Deformation
Number of
Sites
Performing
Unit Op
2,064
139
2,002
12
1,672
12
195
104
454
452
957
892
25
0
149
69
6,369
884
6,911
185
2,513
296
158
66
3,426
Number of
Sites
Performing
Unit Op Wet
461
139
0
12
449
12
106
104
454
452
955
892
0
0
105
69
3,006
884
3,385
185
473
296
33
66
191
Number of
Sites
Generating
Wastewater*1
from Unit Op
406
71
0
0
422
0
103
104
443
387
760
825
0
0
100
69
2,949
134
1,723
78
391
125
4
29
108
Percentage
of Sites
Performing
Unit Op
Wet
22
100
0
100
27
100
54
100
100
100
>99
100
0
0
71
100
47
100
49
100
19
100
21
100
6
Percentage of
Sites
Generating
Wastewater0"
from Wet Op(d)
88
51
0
0
94
0
97
100
97
86
80
92
0
0
94
100
98
15
51
42
83
42
12
44
56
'"All data is based on a scale-up of MP&M Phase I DCP information.
""These totals include sites generating process wastewater that is contract-hauled off site.
"'Solvent degreasing operations reported as using process water are discussed under emulsion cleaning (see unit operation #5).
'•"This percentage is calculated by dividing the number of sites generating wastewater from the unit operation by the number of sites performing
the operation wet. 5-48
-------
Table 5-3 (Continued)
Number of MP&M Sites Using
and Discharging Process Water by Unit Operation00
Unit Operation
26R. Impact Deformation Rinse
27. Laminating
27R. Laminating Rinse
28. Laser Beam Machining
28R. Laser Beam Machining
Rinse
29. Machining
29R. Machining Rinse
30. Metal Spraying
30R. Metal Spraying Rinse
31. Painting
31 R. Painting Rinse
32. Plating
32R. Plating Rinse
33. Plasma Arc Machining
33R. Plasma Arc Machining
Rinse
34. Polishing
34R. Polishing Rinse
35. Pressure Deformation
35R. Pressure Deformation
Rinse
36. Rinsing
37. Salt Bath Descaling
37R. Salt Bath Descaling Rinse
38. Soldering
38R. Soldering Rinse
39. Solvent Degreasing<0)
39R. Solvent Degreasing Rinse
Number of
Sites
Performing
Unit Op
79
821
0
1,109
0
8,603
360
787
21
5,837
447
378
298
951
0
2,733
119
5,350
45
1,758
83
37
4,280
609
6,316
242
Number of
Sites
Performing
Unit Op Wet
79
0
0
0
0
5,167
360
60
21
1,049
447
298
298
233
0
133
119
230
45
1,174
27
37
299
609
92
242
Number of
Sites
Generating
Wastewater*1
from Unit Op
33
0
0
0
0
3,595
141
40
0
886
136
283
292
233
0
128
76
199
45
1,168
27
37
299
517
92
220
Percentage
of Sites
Performing
Unit Op
Wet
100
0
0
0
0
60
100
8
100
18
100
79
100
25
0
5
100
4
100
67
32
100
7
100
1
100
Percentage of
Sites
Generating
Wastewater*'
from Wet Op(d)
42
0
0
0
0
70
39
67
0
85
30
95
98
100
0
96
64
86
100
99
100
100
100
85
100
91
'"All data is based on a scale-up of MP&M Phase I DCP information.
""These totals include sites generating process wastewater that is contract-hauled off site.
'"'Solvent degreasing operations reported as using process water are discussed under emulsion cleaning (see unit operation #5).
""This percentage is calculated by dividing the number of sites generating wastewater from the unit operation by the number of sites performing
the operation wet. 5-49
-------
Table 5-3 (Continued)
Number of MP&M Sites Using
and Discharging Process Water by Unit Operation00
Unit Operation
40. Sputtering
40R. Sputtering Rinse
41. Stripping
41 R. Stripping Rinse
42. Testing
42R. Testing Rinse
43. Thermal Cutting
43R. Thermal Cutting Rinse
44. Thermal Infusion
44R. Thermal Infusion Rinse
45. Ultrasonic Machining
45R. Ultrasonic Machining
Rinse
46. Vacuum Metalizing
46R. Vacuum Metalizing Rinse
47. Welding
47R. Welding Rinse
48. Wet Air Pollution Control
Number of
Sites
Performing
Unit Op
120
0
1,486
966
3,722
473
1,963
0
46
21
28
0
54
0
6,842
36
987
Number of
Sites
Performing
Unit Op Wet
0
0
655
966
1,171
473
180
0
21
21
0
0
0
0
163
36
987
Number of
Sites
Generating
Wastewater0"
from Unit Op
0
0
626
842
1,066
372
110
0
21
0
0
0
0
0
163
23
821
Percentage
of Sites
Performing
Unit Op
Wet
0
0
44
100
31
100
9
0
47
100
0
0
0
0
2
100
100
Percentage of
Sites
Generating
Wastewater*1
from Wet Op
-------
Table 5-4
MP&M Phase I Process Water Discharge Flow
and Purpose of Process Water by Unit Operation
Unit Operation
1. Abrasive Blasting
1R. Abrasive Blasting Rinse
2. Abrasive Jet Machining
2R. Abrasive Jet Machining
Rinse
3. Acid Treatment
3R. Acid Treatment Rinse
4. Adhesive Bonding
4R. Adhesive Bonding Rinse
5. Alkaline Treatment
5R. Alkaline Treatment Rinse
6. Anodizing
6R. Anodizing Rinse
7. Assembly
7R. Assembly Rinse
8. Barrel Finishing
8R. Barrel Finishing Rinse
9. Brazing
9R. Brazing Rinse
10. Burnishing
10R. Burnishing Rinse
11. Calibration
11R. Calibration Rinse
PNP
SA
SA
MMR
MMR
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
Median
PNF
(gal/PNP)
1.03
2.36
1,060"
NA
0.034
2.48
0.022
NA
0.050
1.06
0.032
0.678
0.252
NA
1.17
1.96
NA
10.1
8.02
NA
NA
NA
Purpose of Process Water Use
Typically
Dry or
Not
Performed
/
/
/
/
/
/
/
/
/
/
/
Process
Solution
or Rinse
J
/
/
/
/
/
/
/
S
/
/
/
/
J
/
Coolant/
Lubricant/
Flux
/
Other (see
operation
description)
/
/
/
Total Estimated
Industry
Discharge Plow*'
(million gal/yr)
5.81
11.4
33.8
0
110
3,320
0.464
0
780
4,230
6.12
707
19.0
0.340
704
81.0
0
3.64
1.59
26.5
0.00180
0
'"Note: The PNF for abrasive jet machining is based on only 2 data points.
""These totals do not include process wastewater that is contract hauled off site.
-------
Table 5-4 (Continued)
MP&M Process Water Discharge Flow
and Purpose of Process Water by Unit Operation
Unit Operation
12. Chemical Conversion
Coating
12R. Chemical Conversion
Coating Rinse
13. Chemical Machining
13R. Chemical Machining Rinse
14. Corrosion Preventive
Coating
14R. Corrosion Preventive
Coating Rinse
15. Disassembly
15R. Disassembly Rinse
16. Electrical Discharge
Machining
16R. Electrical Discharge
Machining Rinse
17. Electrochemical Machining
17R. Electrochemical Machining
Rinse
18. Electrolytic Cleaning
18R Electrolytic Cleaning Rinse
19. Electroplating
19R. Electroplating Rinse
20. Electron Beam Machining
20R. Electron Beam Machining
Rinse
PNP
SA
SA
SA
SA
SA
SA
SA
SA
MMR
MMR
SA
SA
SA
SA
SA
SA
SA
SA
Median
PNF
(gaWNP)
0.019
0.260
0.055
10.4
0.008
0.558
NA
NA
4.38
NA
NA
3.87
0.049
1.51
0.060
4.91
NA
NA
Purpose of Process Water Use
Typically
Dry or
Not
Performed
/
/
/
/
/
/
/
/
Process
Solution
or Rinse
/
/
/
/
/
/
/
/
/
/
/
/
/
Coolant/
Lubricant/
Flux
Other (see
operation
description)
Total Estimated
Industry
Discharge Flow*'
(million gal/yr)
622
2,100
2.24
346
14.6
51.1
0
0
1.70
0
37.1
28.3
57.1
1,620
14.9
1,180
0
0
-------
Table 5-4 (Continued)
MP&M Process Water Discharge Flow
and Purpose of Process Water by Unit Operation
Unit Operation
21. Electropolishing
21 R. Electropolishing Rinse
22. Floor Cleaning
22R. Floor Cleaning Rinse
23. Grinding
23R. Grinding Rinse
24. Heat Treating
24R. Heat Treating Rinse
25. Hot Dip Coating
25R. Hot Dip Coating Rinse
26. Impact Deformation
26R. Impact Deformation Rinse
27. Laminating
27R. Laminating Rinse
28. Laser Beam Machining
28R. Laser Beam Machining
Rinse
29. Machining
29R. Machining Rinse
30. Metal Spraying
30R. Metal Spraying Rinse
31. Painting
31 R. Painting Rinse
PNP
SA
SA
SA
SA
MMR
MMR
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
MMR
MMR
SA
SA
SA
SA
Median
PNF
(gal/PNP)
NA
NA
0.005
0.095
0.369
1.99
1.00
7.43
NA
NA
0.174
NA
NA
NA
NA
NA
0.053
7.78
2.25
NA
0.025
0.099
Purpose of Process Water Use
Typically
Dry or
Not
Performed
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
Process
Solution
or Rinse
/
/
/
/
/
/
/
/
/
/
/
/
Coolant/
Lubricant/
Flux
/
/
/
/
Other (see
operation
description)
/
/
/
/
Total Estimated
Industry
Discharge Flow*'
(million gal/yr)
0.0394
14.1
120
2.43
60.7
6.93
594
128
0.000638
73.2
30.2
0.562
0
0
0
0
99.1
1.23
0.0967
0
309
1,020
'"'Note: The PNF for abrasive jet machining is based on only 2 data points.
""These totals do not include process wastewater that is contract hauled off site.
(c)Note: Solvent degreasing operations reported as using process water are discussed under emulsion cleaning (see unit operation #5).
PNP - Production normalizing parameter. Either surface area (measured in square feet), mass of metal removal (measured in pounds
removed), or airflow (measured in standard cubic feet of air).
PNF - Production normalized flow.
NA - Not available. Insufficient flow and production data provided in DCPs.
SA - Surface area of parts.
MMR - Mass of metal removed from parts.
SCF - Standard cubic feet of air. 5-53
-------
Table 5-4 (Continued)
MP&M Process Water Discharge Flow
and Purpose of Process Water by Unit Operation
Unit Operation
32. Plating
32R. Plating Rinse
33. Plasma Arc Machining
33R. Plasma Arc Machining
Rinse
34. Polishing
34R. Polishing Rinse
35. Pressure Deformation
35 R. Pressure Deformation
Rinse
36. Rinsing
37. Salt Bath Descaling
37R. Salt Bath Descaling Rinse
38. Soldering
38R. Soldering Rinse
39. Solvent Degreasing'01
39R. Solvent Degreasing Rinse
40. Sputtering
40R. Sputtering Rinse
41. Stripping
41 R. Stripping Rinse
42. Testing
42R. Testing Rinse
PNP
SA
SA
MMR
MMR
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
Median
PNF
(gal/PNP)
0.030
6.87
4.00
NA
1.44
13.9
0.011
NA
0.509
NA
1.50
27.8
3.03
0.094
2.86
NA
NA
0.300
7.84
1.35
0.875
Purpose of Process Water Use
Typically
Dry or
Not
Performed
/
/
/
^
/
/
S
/
/
/
S
^
Process
Solution
or Rinse
/
•/•
/
/
/
/
/
/
/
./•
/
/
/
Coolant/
Lubricant/
Flux
/
/
Other (see
operation
description)
S
/
/
Total Estimated
Industry
Discharge Flow0"
(million gal/yr)
5.02
196
36.2
0
23.1
13.9
41.3
31.3
694
484
5.07
18.5
72.4
20.0
53.7
0
0
13.8
273
491
94.5
'"Note: The PNF for abrasive jet machining is based on only 2 data points.
""These totals do not include process wastewater that is contract hauled off site.
|c|Note: Solvent degreasing operations reported as using process water are discussed under emulsion cleaning (see unit operation #5).
PNP - Production normalizing parameter. Either surface area (measured in square feet), mass of metal removal (measured in pounds
removed), or airflow (measured in standard cubic feet of air).
PNF - Production normalized flow.
NA - Not available. Insufficient flow and production data provided in DCPs.
SA - Surface area of parts.
MMR - Mass of metal removed from parts.
SCF - Standard cubic feet of air. 5-54
-------
Table 5-4 (Continued)
MP&M Process Water Discharge Flow
and Purpose of Process Water by Unit Operation
Unit Operation
43. Thermal Cutting
43R. Thermal Cutting Rinse
44. Thermal Infusion
44R. Thermal Infusion Rinse
45. Ultrasonic Machining
45 R. Ultrasonic Machining
Rinse
46. Vacuum Metalizing
46R. Vacuum Metalizing Rinse
47. Welding
47R. Welding Rinse
48. Wet Air Pollution Control
PNP
SA
SA
SA
SA
SA
SA
SA
SA
SA
SA
SCF
Median
PNF
(gal/PNP)
0.134
NA
NA
NA
NA
NA
NA
NA
0.071
30.7
0.0002
Purpose of Process Water Use
Typically
Dry or
Not
Performed
/
/
/
/
/
/
J
/
/
Process
Solution
or Rinse
/
Coolant/
Lubricant/
Flux
/
/
Other (see
operation
description)
S
S
Total Estimated
Industry
Discharge Flow""1
(million gal/yr)
2.31
0
1.15
0
0
0
0
0
19.0
27.4
1,610
Source: MP&M Phase I DCP database.
'"Note: The PNF for abrasive jet machining is based on only 2 data points.
"'These totals do not include process wastewater that is contract hauled off site.
(0)Note: Solvent degreasing operations reported as using process water are discussed under emulsion cleaning (see unit operation #5).
PNP - Production normalizing parameter. Either surface area (measured in square feet), mass of metal removal (measured in pounds
removed), or airflow (measured in standard cubic feet of air).
PNF - Production normalized flow.
NA - Not available. Insufficient flow and production data provided in DCPs.
SA - Surface area of parts.
MMR - Mass of metal removed from parts.
SCF - Standard cubic feet of air. 5-55
-------
5.12 References
1. Cubberly, William H. (ed.). Tool and Manufacturing Engineers Handbook. Desk
Edition. Society of Manufacturing Engineers, Dearborne, MI, 1989.
2. Detrisac, M. Arthur. "Treatable Cleaners," Metal Finishing, September 1991.
3. Development Document for Effluent Limitations Guidelines and Standards for the Metal
Finishing Point Source Category. U.S. Environmental Protection Agency, EPA 440/1-
83/091, June 1983.
4. Mohler, J.B. "Alkaline Cleaning for Electroplating," Metal Finishing, September 1984.
5. Wood, William G. (Coordinator). The New Metals Handbook, Vol. 5. Surface
Cleaning. Finishing, and Coating. American Society for Metals, May 1990.
6. Lowenheim, Frederick A., Electroplating Fundamentals of Surface Finishing. McGraw-
Hill Book Company, New York, NY, 1978.
7. Murphy, Michael (ed.). Metal Finishing Guidebook and Directory Issue '93. Metal
Finishing, January 1993.
5-56
-------
6.0 WASTEWATER CHARACTERISTICS
6.0 WASTEWATER CHARACTERISTICS
This section summarizes the characteristics of wastewaters discharged from Metal
Products and Machinery (MP&M) unit operations and raw wastewater entering end-of-
pipe treatment operations. Characteristics of MP&M treated effluent wastewaters are
presented in Section 11.0. The data presented in this section were obtained from the
MP&M data collection portfolios (DCPs) and the MP&M sampling program (discussed
in Sections 4.2 and 4.4, respectively). The DCP requested sites to indicate which
pollutants were known or believed to be present on site, as well as which unit operations
were the sources of these pollutants. Through the sampling program, the Agency
obtained analytical data for the unit operations and treatment system influent and
effluent streams known or believed to contain toxic pollutants at MP&M sites.
Section 6.1 summarizes analytical data for wastewaters from MP&M unit operations.
Section 6.2 summarizes analytical data for influent wastewater streams to chemical
precipitation and sedimentation, cyanide destruction, and oil/water separation systems.
These technologies were used as the basis for calculating the MP&M Phase I limitations.
Tables 6-1 through 6-12 are located at the end of this section.
6.1 Wastewater Characteristics by Unit Operation
As discussed in Section 5.0, EPA evaluated data for 48 distinct unit operations
performed at MP&M Phase I sites. During the MP&M Phase I data-gathering efforts,
EPA identified several additional unit operations performed at MP&M Phase I sites.
Many of the MP&M unit operations were reported in the DCPs as discharging process
water, and many also have associated rinses that discharge process water. Several of
these unit operations and associated rinses have been divided into suboperations for the
purposes of estimating compliance costs (see Section 12.0) and pollutant loadings (see
Section 13.0). EPA divided the list of 48 operations into 132 suboperations (including
rinses) that were reported by DCP respondents as discharging process water. Table 6-1
lists the 132 suboperations.
During the MP&M sampling program, EPA collected wastewater samples from 70 of the
MP&M suboperations. Table 6-1 lists the number of wastewater samples collected from
these suboperations. The 70 suboperations represent operations discharging
approximately 90% of the MP&M Phase I process wastewater. Wastewater
characteristics for the other 93 suboperations were modelled based on the samples
collected for these 70 suboperations, as discussed in Section 13.0.
Wastewaters generated from MP&M unit operations can be classified into the following
types based on their composition and treatment requirements:
• Hexavalent chromium-bearing wastewaters;
• Cyanide-bearing wastewaters;
6-1
-------
6.0 WASTEWATER CHARACTERISTICS
• Oil-bearing wastewaters;
• Chelated metal-bearing wastewaters; and
• Metal-bearing wastewaters.
The unit operations generating each of these types of wastewater are discussed below,
along with the pollutants and treatment requirements associated with each type. For
each type of wastewater, the following data are presented:
• A summary of analytical data collected from the unit operations
generating that type of wastewater. The summary lists, for each
pollutant analyzed, the number of samples analyzed, the number of
times the pollutant was detected, and the minimum, maximum,
mean, and median detected concentrations.
• A summary of analytical data from rinses associated with the unit
operations generating that type of wastewater. This summary
presents the same information as the summary described above.
• A summary of DCP responses identifying pollutants known or
believed to be present in wastewaters from the unit operations and
rinses generating that type of wastewater.
Unit operation-specific analytical data for the operations sampled during the MP&M
sampling program are contained in the administrative record for this rulemaking.
6.1.1
Hexavalent Chromium-Bearing Wastewaters
The following MP&M unit operations and associated rinses generate hexavalent
chromium-bearing wastewaters.
Unit Operations and Rinses That Generate Hexavalent Chromium-Bearing Wastewater
Unit Operation
Associated Rinse
Anodizing Sealant (with hexavalent chromium)
Chemical Conversion Coating Sealant (with hexavalent
chromium)
Chromate Conversion Coating
Chromic Acid Anodizing
Chromic Acid Treatjnent
Chromium Electroplating
Electroplating Sealant (with hexavalent chromium)
Wet Air Pollution Control for Chromium-Bearing Operations
Anodizing Sealant (with hexavalent chromium) - Rinse
Chemical Conversion Coating Sealant (with
hexavalent chromium) - Rinse
Chromate Conversion Coating - Rinse
Chromic Acid Anodizing - Rinse
Chromic Acid Treatment - Rinse
Chromium Electroplating - Rinse
Electroplating Sealant (with hexavalent chromium) -
Rinse
Not Applicable
Source: MP&M DCPs, MP&M site visits, technical literature.
6-2
-------
6.0 WASTEWATER CHARACTERISTICS
These wastewaters generally require preliminary treatment to reduce hexavalent
chromium to trivalent chromium prior to commingling with other types of wastewaters
for further end-of-pipe treatment. Chromium reduction technologies generally involve
using reducing agents, such as sodium metabisulfite, under acidic conditions to reduce
hexavalent chromium to trivalent chromium. Section 10.0 discusses in detail the
chromium reduction technologies used in the MP&M industry.
Hexavalent chromium is present in the wastewater as a component of the process bath
(e.g., chromic acid anodizing, chromate conversion coating, chromium electroplating).
The following table summarizes the analytical data collected during the MP&M sampling
program for chromium in wastewater from unit operations and associated rinses that
generate hexavalent chromium-bearing wastewater.
Summary of Analytical Data for Chromium
From Hexavalent Chromium-Bearing Wastewaters
Source of Pollutant
Unit Operations
Generating Hexavalent
Chromium-Bearing
Wastewater
Rinses Generating
Hexavalent
Chromium-Bearing
Wastewater
Number of
Samples
Analyzed
28
37
Number
of
Detects
28
37
Minimum
Detected
Concentration
(mg/L)
0.360
0.027
Maximum
Detected
Concentration
(mg/L)
39,000
1,760
Mean
Detected
Concentration
(mg/L)
23,500
222
Median
Detected
Concentration
(mg/L)
2,210
12.8
Source: MP&M Sampling Program.
The concentrations represent the concentration of total chromium in the wastewater;
based on the process chemistry of the unit operations (e.g., the chromium is present in
the hexavalent form in a chromic acid solution), the Agency believes that most of the
chromium present in these wastewaters is in the hexavalent form. For the purposes of
estimating compliance costs, the Agency assumed that all chromium in these wastewaters
is in the hexavalent form.
Table 6-2 summarizes qualitative data contained in response to the MP&M DCPs,
indicating the pollutant parameters known or believed to be present in wastewaters from
unit operations and rinses that generate hexavalent chromium-bearing wastewater. As
shown in Table 6-2, chromium was the pollutant identified most frequently as known or
believed to be present in these wastewaters.
6-3
-------
6.0 WASTEWATER CHARACTERISTICS
6.1.2
Cyanide-Bearing Wastewaters
The following MP&M unit operations and associated rinses generate cyanide-bearing
wastewaters.
Unit Operations and Rinses
That Generate Cyanide-Bearing Wastewater
Unit Operation
Associated Rinse
Alkaline Cyanide Cleaning
Cyaniding Quench
Electrolytic Cleaning (with cyanide)
Electroplating (with cyanide)
Wet Air Pollution Control for Cyanide-
Bearing Operations
Alkaline Cyanide Cleaning - Rinse
Cyaniding Quench - Rinse
Electrolytic Cleaning (with cyanide) - Rinse
Electroplating (with cyanide) - Rinse
Not Applicable
Source: MP&M DCPs, MP&M site visits, technical literature.
These wastewaters generally require preliminary treatment to oxidize cyanide to carbon
dioxide and nitrogen. This process generally entails using chlorine as either chlorine gas
or sodium hypochlorite, under alkaline conditions, in a two-step process. In the first
step, cyanides are oxidized to form cyanates and, in the second step, cyanates are
oxidized to form carbon dioxide and nitrogen. Section 10.0 discusses in detail cyanide
destruction technologies used in the MP&M industry.
Cyanide is present in the wastewater as a component of electroplating and cleaning
baths. The following table summarizes the analytical data collected during the MP&M
sampling program for cyanide from unit operations and their associated rinses that
generate cyanide-bearing wastewater. Cyanide electroplating baths and rinses also
contain several metal pollutants (typically cadmium, copper, or silver) depending on the
type of metal being electroplated. In samples of these electroplating wastewaters, the
metal being applied has been detected at concentrations of up to 43,400 mg/L in the
electroplating solution and 23,500 mg/L in the electroplating rinse.
6-4
-------
6.0 WASTEWATER CHARACTERISTICS
Summary of Analytical Data for Cyanide
From Cyanide-Bearing Wastewaters
Source of Pollutant
Unit Operations
Generating Cyanide-
Bearing Wastewater
Rinses Generating
Cyanide-Bearing
Wastewater
Number of
Samples
Analyzed
12
14
Number
of
Detects
12
13
Minimum
Detected
Concentration
(mg/L)
0.120
0.430
Maximum
Detected
Concentration
(mg/L)
100,000
51,000
Mean
Detected
Concentration
(mg/L)
20,200
10,400
Median
Detected
Concentration
(mg/L)
9,990
10.0
Source: MP&M Sampling Program.
Table 6-3 summarizes qualitative data contained in the MP&M DCPs indicating the
pollutant parameters known or believed to be present in wastewaters from unit
operations and rinses that generate cyanide-bearing wastewater. As shown in Table 6-3,
cyanide and copper were the pollutants most frequently known to be present in
wastewater from cyanide-bearing operations and rinses, while cyanide and cadmium were
the pollutants most frequently believed to be present in these wastewaters. Copper and
cadmium are typical metals present in electroplating baths.
6.1.3
Oil-Bearing Wastewaters
The following MP&M unit operations and associated rinses generate oil-bearing
wastewaters.
Unit Operations and Rinses That Generate Oil-Bearing Wastewater
Unit Operation
Associated Rinse
Alkaline Treatment (requiring oil treatment)
Corrosion Preventive Coating
Dye Penetrant Testing
Floor Cleaning
Grinding
Heat Treating (requiring oil treatment)
Impact Deformation
Machining
Magnetic Flux Testing
Pressure Deformation
Solvent Degreasing
Alkaline Treatment (requiring oil treatment) - Rinse
Corrosion Preventive Coating - Rinse
Dye Penetrant Testing - Rinse
Floor Cleaning - Rinse
Grinding - Rinse
Heat Treating (requiring oil treatment) - Rinse
Impact Deformation - Rinse
Machining - Rinse
Magnetic Flux Testing - Rinse
Pressure Deformation - Rinse
Solvent Decreasing - Rinse
Source: MP&M DCPs, MP&M site visits, technical literature.
6-5
-------
6.0 WASTEWATER CHARACTERISTICS
These wastewaters generally require preliminary treatment to separate oil from the
wastewater. If the oils are free or floating, then the oil and water can generally be
separated using physical means such as oil skimming or ultrafiltration. If the oil is
emulsified, techniques such as chemical emulsion breaking may be used prior to physical
separation. These oil/water separation technologies also remove organic pollutants that
are more soluble in oil than in water. Section 10.0 discusses in detail oil/water
separation technologies used in the MP&M industry.
Tables 6-4 and 6-5 summarize the analytical data collected during the MP&M sampling
program for wastewater from unit operations and their associated rinses, respectively,
that generate oil-bearing wastewater. Oil/water emulsions are typically used as coolants
and lubricants in machining, grinding, and deformation operations. Oil is also present as
a contaminant in wastewater from cleaning operations. The maximum concentration of
oil and grease detected in wastewater from the unit operations was 570,000 mg/L (from
a machining coolant), while the maximum concentration of oil and grease detected in the
wastewater from the rinses associated with these unit operations was 2,700 rng/L.
Table 6-6 summarizes qualitative data contained in the MP&M DCPs indicating the
pollutant parameters known or believed to be present in wastewaters from unit
operations and rinses that generate oil-bearing wastewater. As shown in Table 6-6, 1,1,1-
trichloroethane, chromium, copper, lead, nickel, and zinc were the pollutants most
frequently known or believed to be present in wastewater from oil-bearing operations
and rinses.
6.1.4 Chelated Metal-Bearing Wastewaters
Electroless plating operations and rinses are the most common MP&M operations that
generate chelated metal-bearing wastewaters. Some cleaning operations also generate
chelated metal-bearing wastewaters. Chelating agents are used in these unit operations
to prevent metals from precipitating out of solution in the process bath. These chelated
metals are not effectively removed by typical chemical precipitation and sedimentation
treatment units. Therefore, these wastewaters generally require preliminary treatment to
break down the metal chelates. This preliminary treatment may consist of chemical
reduction using reducing agents such as sodium borohydride, hydrazine, or sodium
hydrosulfite; high-pH precipitation using calcium hydroxide; or filtering the chelated
metals out of solution. Section 10.0 discusses in detail the chelated metal-bearing
wastewater treatment technologies used in the MP&M industry.
During the MP&M sampling program, the Agency collected samples of electroless nickel
plating solutions and rinses that generate chelated metal-bearing wastewater. The
following table summarizes the analytical data for nickel in these samples.
6-6
-------
6.0 WASTEWATER CHARACTERISTICS
Summary of Analytical Data for Nickel in Electroless Plating Wastewaters
•
Source of Pollutant
Electroless Nickel
Plating Solution
Electroless Nickel
Plating Rinse
Number of
Samples
Analyzed
2
6
Number
of
Detects
2
6
Minimum
Detected
Concentration
(mg/L)
5,030
2.43
IVfaximum
Detected
Concentration
(mg/L)
6,280
378
Mean
Detected
Concentration
(mg/L)
5,660
102
Median
Detected
Concentration
(mg/L)
5,660
46.6
Source: MP&M Sampling Program.
Other metals typically plated using electroless plating include copper, gold, palladium,
and cobalt. The Agency expects the concentration of the plated metals in these solutions
and associated rinses to be similar to the concentrations measured for nickel during the
MP&M sampling program.
Table 6-7 summarizes qualitative data contained in the MP&M DCPs indicating the
pollutant parameters known or believed to be present in wastewaters from unit
operations and rinses that generate chelated metal-bearing wastewater. As shown in
Table 6-7, nickel was most frequently known or believed to be present in wastewater
from chelated metal-bearing wastewaters.
6.1.5
Metal-Bearing Wastewaters
All of the MP&M unit operations generate metal-bearing wastewaters. These
wastewaters include those classified in the four types of wastewater described previously.
After preliminary treatment for selected streams, these wastewaters are generally treated
using chemical precipitation and sedimentation. This process involves precipitating the
metals under alkaline conditions, usually by adding calcium or sodium hydroxide, and
settling the precipitated metals, usually by clarification. Section 10.0 discusses in detail
metal-bearing wastewater treatment technologies used in the MP&M industry.
Tables 6-8 and 6-9 summarize the analytical data collected during the MP&M sampling
program for wastewater from unit operations and associated rinses, respectively, that
generate metal-bearing wastewater. As shown in these tables, the priority metal
pollutants most commonly detected in samples of these wastewaters were cadmium,
chromium, copper, nickel, and zinc. Nonconventional metal pollutants frequently
detected include aluminum, boron, iron, magnesium, manganese, and molybdenum.
Metal pollutants are typically present either in the base metal processed or in process
solutions. The maximum concentrations of these metal pollutants detected in wastewater
from the unit operations ranged from 7,150 to 374,000 mg/L (for electroplating
solutions), while the maximum concentrations in the associated rinses ranged from 6.82
6-7
-------
6.0 WASTEWATER CHARACTERISTICS
to 2,830 mg/L. These wastewaters also typically contained oil and grease and total
suspended solids.
Table 6-10 summarizes qualitative data contained in the MP&M DCPs indicating the
pollutant parameters known or believed to be present in wastewaters from unit
operations and rinses that generate metal-bearing wastewater. As shown in Table 6-10,
chromium, copper, and nickel were the pollutants most frequently known to be present
in wastewater from metal-bearing operations and rinses, while chromium and lead were
the pollutants most frequently believed to be present in these wastewaters.
6.1.6 Qualitative Data from the MP&M DCPs for Unidentified MP&M Unit
Operations
Table 6-11 summarizes qualitative data contained in the MP&M DCPs indicating the
pollutant parameters known or believed to be present in wastewaters generated by
unspecified MP&M unit operations. Although the specific unit operations generating
these wastewaters were not identified in the DCPs, the data provided in the DCPs
identify pollutant parameters that are known or believed to be present in raw MP&M
wastewater prior to end-of-pipe treatment.
As shown in Table 6-11, copper, lead, and zinc were the pollutants most frequently
known to be present in these wastewaters, while chromium, copper, and nickel were the
pollutants most frequently believed to be present in these wastewaters.
6.2 Treatment Influent Characteristics
Table 6-12 summarizes analytical data collected during the MP&M sampling program for
influent wastewaters to chemical precipitation and sedimentation treatment systems. As
shown in this table, the priority metal pollutants most frequently detected in samples of
these wastewaters collected during the MP&M sampling program were chromium,
copper, nickel, and zinc. Nonconventional metal pollutants frequently detected include
aluminum, boron, iron, magnesium, and manganese. The maximum concentrations of
these metal pollutants ranged from 59.8 to 3,880 mg/L. These wastewaters also contain
oil and grease and total suspended solids.
The following table summarizes the analytical data collected for cyanide in influent
wastewaters to cyanide destruction systems. The streams also contained metal pollutants
and total suspended solids.
6-8
-------
6.0 WASTEWATER CHARACTERISTICS
Summary of Analytical Data for Cyanide in Cyanide Destruction Influent Streams
Number of
Samples
Analyzed
20
Number
of Detects
20
Minimum
Detected
Concentration
(mg/L)
0.062
Maximum
Detected
Concentration
(mg/L)
119
Mean
Detected
Concentration
(mg/L)
25.3
Median
Detected
Concentration
(mg/L)
8.75
Source: MP&M Sampling Program.
The following table summarizes the analytical data collected for oil and grease in
influent wastewater to oil skimming, chemical emulsion breaking, and ultrafiltration
treatment systems. These streams also contain organic pollutants, metal pollutants, and
total suspended solids.
Summary of Analytical Data for Oil and Grease
in Oil/Water Separation Influent Streams
Number of
Samples
Analyzed
23
Number
of Detects
23
Minimum
Detected
Concentration
(mg/L)
16
Maximum
Detected
Concentration
(mg/L)
262,000
Mean Detected
Concentration
(mg/L)
22,000
Median
Detected
Concentration
(mg/L)
170
Source: MP&M Sampling Program.
6-9
-------
Table 6-1
Number of Samples Collected for MP&M Phase I Unit Operations
Unit Operation
No. of
Samples
Collected
Unit Operation
No. of
Samples
Collected
Abrasive Blasting
Abrasive Blasting-Rinse
Abrasive Jet Machining
Abrasive Jet Machining-Rinse
Acid Treatment (with chromic acid)
Acid Treatment (with chromic acid)-Rinse
Acid Treatment
Acid Treatment-Rinse
Adhesive Bonding
Adhesive Bonding-Rinse
Alkaline Treatment (requiring oil treatment)
Alkaline Treatment (requiring oil treatment)-Rinse
Alkaline Treatment (with cyanide)
Alkaline Treatment (with cyanide)-Rinse
Alkaline Treatment
Alkaline Treatment-Rinse
Acid Anodizing (with chromic acid)
Acid Anodizing (with chromic acid)-Rinse
Anodizing Sealant (with hexavalent chromium)
Anodizing Sealant (with hexavalent
chromium)-Rinse
Anodizing (without hexavalent chromium)
Anodizing (without hexavalent chromium)-Rinse
Anodizing Sealant (without hexavalent chromium)
Anodizing Sealant (without hexavalent
chromium)-Rinse
3
3
1
0
2
5
18
22
0
0
23
11
20
28
Assembly
Assembly-Rinse
Barrel Finishing
Barrel Finishing-Rinse
Brazing
Brazing-Rinse
Burnishing
Burnishing-Rinse
Calibration
Chromate Conversion Coating
Chromate Conversion Coating-Rinse
Chemical Conversion Coating Sealant (with hexavalent
chromium)
Chemical Conversion Coating Sealant (with hexavalent
chromium)-Rinse
Chemical Conversion Coating (without hexavalent
chromium)
Chemical Conversion Coating (without hexavalent
chromium)-Rinse
Chemical Conversion Coating Sealant (without hexavalent
chromium)
Chemical Conversion Coating Sealant (without hexavalent
chromium)-Rinse
Chemical Machining
Chemical Machining-Rinse
Corrosion Preventive Coating
Corrosion Preventive Coating-Rinse
Disassembly
Disassembly-Rinse
Electrical Discharge-Machining
0
0
6
0
0
0
0
0
0
9
16
4
12
22
6-10
-------
Table 6-1 (Continued)
Number of Samples Collected for MP&M Phase I Unit Operations
Unit Operation
Electrochemical Machining
Electrochemical Machining-Rinse
Electrolytic Cleaning (with cyanide)
Electrolytic Cleaning (with cyanide)-Rinse
Electrolytic Cleaning (without cyanide)
Electrolytic Cleaning (without cyanide)-Rinse
Electroplating (with chromium)
Electroplating (with chromium)-Rinse
Electroplating (with cyanide)
Electroplating (with cyanide)-Rinse
Electroplating (without hexavalent chromium or
cyanide)
Electroplating (without hexavalent chromium or
cyanide)-Rinse
Electron Beam Machining
Electropolishing
Electropolishing-Rinse
Floor Cleaning
Grinding
Grinding-Rinse
Heat Treating Quench
Heat Treating Quench-Rinse
Heat Treating (solution) Quench
Heat Treating (solution) Quench-Rinse
Heat Treating (cyaniding) Quench
Heat Treating (cyaniding) Quench-Rinse
Hot Dip Coating
Hot Dip Coating-Rinse
Impact Deformation
Impact Deformation-Rinse
Laminating
Laser Beam Machining
No. of
Samples
Collected
1
2
1
1
6
12
4
11
8
13
12
18
0
1
1
6
5
0
3
5
2
0
0
0
0
0
1
0
0
0
Unit Operation
Machining
Machining-Rinse
Metal Spraying
Painting (including water curtains)
Painting-Rinse
Painting-Electrophoretic
Plating— Electroless and Immersion
Plating— Electroless and Immersion-Rinse
Plating-Mechanical and Vapor
Plating-Mechanical and Vapor-Rinse
Plasma Arc Machining
Polishing
Polishing-Rinse
Pressure Deformation
Pressure Deformation-Rinse
Rinsing
Rinsing— Multiple Unit Operation
Salt Bath Descaling
Salt Bath Descaling-Rinse
Soldering
Soldering-Rinse
Solvent Degreasing
Solvent Degreasing-Rinse
Sputtering
Stripping-Metallic Coating
Stripping-Metallic Coating-Rinse
Stripping-Organic Coating
Stripping-Organic Coating-Rinse
Testing-Dye Penetrant
Testing-Dye Penetrant-Rinse
No. of
Samples
Collected
12
0
0
0
2
6
0
0
1
0
0
0
0
1
1
0
3
0
0
0
0
0
9
3
4
7
2
3
0
6-11
-------
Table 6-1 (Continued)
Number of Samples Collected for MP&M Phase I Unit Operations
Unit Operation
Testing-Hydraulic
Testing-Hydraulic-Rinse
Testing-Electrical
Testing-Performance
Testing-Performance-Rinse
Testing-Magnetic Flux
Testing-Magnetic Flux-Rinse
Testing-Ultrasonic
Testing-Ultrasonic-Rinse
Testing-Salt Spray
Testing- Radiographic
Testing Undefined
No. of
Samples
Collected
0
0
0
0
0
0
0
0
0
0
0
0
Unit Operation
Thermal Cutting
Thermal Infusion
Thermal Infusion-Rinse
Ultrasonic Machining
Ultrasonic Machining-Rinse
Vacuum Metalizing
Welding
Welding-Rinse
Wet Air Pollution Control - Chromium-bearing furans
Wet Air Pollution Control - Cyanide-bearing furans
Wet Air Pollution Control - Acid/ Alkaline-bearing furans
Wet Air Pollution Control - Other Fumes and Dusts
No. of
Samples
Collected
3
0
0
0
0
0
0
0
6
4
5
6
Source: MP&M Sampling Program.
6-12
-------
Table 6-2
Pollutant Parameters Identified in the MP&M Data Collection Portfolios
for Hexavalent Chromium-Bearing Unit Operations and Associated Rinses
Pollutant Parameter
No. of "Known to be Present"
Responses
No. of "Believed to be Present"
Responses
PRIORITY POLLUTANTS
CADMIUM
CHROMIUM
COPPER
CYANIDE
LEAD
NICKEL
SILVER
ZINC
6
75
6
7
9
7
3
12
1
11
1
1
2
2
1
2
NONCONVENTIONAL ORGANIC POLLUTANTS
2-BUTANONE
0
1
NONCONVENTIONAL METAL ORGANIC POLLUTANTS
BARIUM
1
1
Source: MP&M DCPs.
6-13
-------
Table 6-3
Pollutant Parameters Identified in the MP&M Data Collection Portfolios
for Cyanide-Bearing Unit Operations and Associated Rinses
Pollutant Parameter
No. of "Known to be Present"
Responses
No. of "Believed to be Present"
Responses
PRIORITY POLLUTANTS
CADMIUM
CHROMIUM
COPPER
CYANIDE
LEAD
NICKEL
SILVER
ZINC
7
2
18
27
2
3
8
5
2
0
0
3
0
0
1
0
Source: MP&M DCPs.
6-14
-------
Table 6-4
Analytical Data for Unit Operations Generating Oil-Bearing Wastewater(a)
Pollutant Parameter
No. of
Samples
Analyzed
No. of
Detects
Min. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean Detected
Concentration
(mg/L)
Median Detected
Concentration
(mg/L)
PRIORITY POLLUTANTS
ACROLEIN
1 , 1 , 1-TRICHLO ROETHANE
4-CHLORO-3-METHYLPHENOL
METHYLENE CHLORIDE
PHENOL
BIS(2-ETHYLHEXYL) PHTHALATE
TOLUENE
ANTIMONY
ARSENIC
BERYLLIUM
CADMIUM
CHROMIUM
COPPER
CYANIDE
LEAD
MERCURY
NICKEL
SELENIUM
SILVER
THALLIUM
ZINC
5
5
5
5
5
5
5
53
54
54
54
54
54
2
54
54
54
53
54
53
54
1
2
4
1
1
1
4
28
31
22
44
53
52
1
40
23
52
17
34
16
53
0.161
0.010
42.113
0.028
1.695
143.047
0.094
0.008
0.001
0.000
0.005
0.007
0.006
0.050
0.050
< 0.001
0.013
0.001
0.004
0.002
0.021
0.161
0.012
91.125
0.028
1.695
143.047
0.653
0.328
1.740
0.260
8.100
255.000
81.500
0.050
53.900
0.033
80.900
0.789
3.140
0.036
561.000
0.161
0.011
60.149
0.028
1.695
143.047
0.245
0.093
0.142
0.014
1.028
5.445
5.687
0.050
3.606
0.004
2.446
0.058
0.245
0.016
20.077
0.161
0.011
53.678
0.028
1.695
143.047
0.117
0.041
0.015
0.001
0.132
0.157
1.415
0.050
0.608
< 0.001
0.218
0.002
0.011
0.021
2.170
CONVENTIONAL POLLUTANTS
OIL AND GREASE
TOTAL SUSPENDED SOLIDS
54
54
54
53
5.000
2.000
570,000
27,200
33,900
1,940
2,150
445
NONCONVENTIONAL ORGANIC POLLUTANTS
2-BUTANONE
2-PROPANONE
ALPHA-TERPINEOL
HEXANOIC ACID
5
5
5
5
1
4
1
3
0.074
0.172
14.055
1.624
0.074
0.228
14.055
36.619
0.074
0.198
14.055
14.507
0.074
0.196
14.055
5.279
(a)This table presents data only for pollutants that were detected in these wastewaters during the MP&M sampling program. In addition to the
pollutants listed, 11 priority organic and 133 nonconventional organic pollutants were analyzed for in five samples and not detected.
6-15
-------
Table 6-4 (Continued)
Analytical Data for Unit Operations Generating Oil-Bearing Wastewater(a)
Pollutant Parameter
No. of
Samples
Analyzed
No. of
Detects
Min. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean Detected
Concentration
(mg/L)
Median Detected
Concentration
(mg/L)
NONCONVENTIONAL ORGANIC POLLUTANTS (Continued)
ISOBUTYL ALCOHOL
N-DOCOSANE
N-DODECANE
N-EICOSANE
N-HEXACOSANE
N-HEXADECANE
N-OCTACOSANE
N-OCTADECANE
N-TETRACOSANE
N-TETRADECANE
N-TRIACONTANE
TRIPROPYLENEGLYCOL METHYL
ETHER
5
5
5
5
5
5
5
5
5
5
5
5
3
2
2
1
2
3
2
2
2
2
2
2
0.012
30.686
20.758
13.130
23.388
5.067
20.008
62,896
31.441
25.153
9.158
413.473
0.019
140.634
36.773
13.130
108.717
95.275
61.093
263.958
116.220
48.532
31.895
10489.094
0.016
85.660
28.766
13.130
66.053
54.328
40,550
163.427
73.831
36.842
20.527
5451.283
0.016
85.660
28.766
13.130
66.053
62.642
40.550
163.427
73.831
36.842
20.527
5451.283
NONCONVENTIONAL METAL POLLUTANTS
ALUMINUM
BARIUM
BORON
CALCIUM
COBALT
IRON
MAGNESIUM
MANGANESE
MOLYBDENUM
SODIUM
TIN
TITANIUM
VANADIUM
YTTRIUM
54
54
54
54
54
54
54
54
54
54
54
54
54
54
48
49
51
53
37
54
51
52
43
54
34
41
33
27
0.039
0.002
0.061
2.080
0.009
0.131
1.200
0.004
0.008
1.610
0.030
0.002
0.007
0.001
197.000
31.980
543.000
474.000
283.000
496.000
99.800
24.100
3.780
31000.000
8.250
1.550
0.150
0.181
20.331
3.065
54.691
70.924
7.789
34.332
18.664
1.911
0.433
1940.161
0.407
0.206
0.045
0.019
2.405
0.308
1.560
52.600
0.039
16.150
12.900
0.487
0.200
314.730
0.085
0.039
0.023
0.003
(a)This table presents data only for pollutants that were detected in these wastcwaters during the MP&M sampling program. In addition to the
pollutants listed, 77 priority organic and 133 nonconventional organic pollutants were analyzed for in five samples and not detected.
6-16
-------
Table 6-4 (Continued)
Analytical Data for Unit Operations Generating Oil-Bearing Wastewater(a)
Pollutant Parameter
No. of
Samples
Analyzed
No. of
Detects
Miii. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean Detected
Concentration
(mg/L)
Median Detected
Concentration
(mg/L)
OTHER NONCONVENTIONAL POLLUTANTS
ACIDITY
TOTAL ALKALINITY
AMMONIA AS NITROGEN
CHEMICAL OXYGEN DEMAND
CHLORIDE
FLUORIDE
SULFATE
TOTAL DISSOLVED SOLIDS
TOTAL KJELDAHL NITROGEN
TOTAL PHOSPHORUS
TOTAL RECOVERABLE PHENOLICS
49
50
27
36
47
50
48
54
27
25
37
23
49
26
36
44
49
40
54
27
25
32
1.000
22.000
0.160
430.000
7.000
0.050
26.000
510.000
0.200
0.020
0.017
250000.000
54000.000
460.000
890000.000
2300.000
25.000
46000.000
411420.000
580.000
7170.000
79.000
10972.087
5822.878
21.687
67447.222
221.686
2.650
2855.100
31422.426
94.943
337.844
6.536
8.000
1900.000
1.450
9900.000
140.950
0.690
226.000
7250.000
43.000
18.700
0.194
Source: MP&M Sampling Program.
(a)This table presents data only for pollutants that were detected in these wastewaters during the MP&M sampling program. In addition to the
pollutants listed, 77 priority organic and 133 nonconventional organic pollutants were analyzed for in five samples and not detected.
6-17
-------
Table 6-5
Analytical Data for Rinses Generating Oil-Bearing Wastewater(a)
Pollutant Parameter
No. of
Samples
Analyzed
No. of
Detects
Mm. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean Detected
Concentration
(mg/L)
Median Detected
Concentration
(mg/L)
PRIORITY POLLUTANTS
1,1,1-TRICHLOROETHANE
1 , 1-DICHLOROETHANE
METHYLENE CHLORIDE
PHENOL
ANTIMONY
ARSENIC
BERYLLIUM
CADMIUM
CHROMIUM
COPPER
LEAD
MERCURY
NICKEL
SELENIUM
SILVER
THALLIUM
ZINC
2
2
2
2
13
14
14
14
14
14
14
14
14
13
14
13
14
1
1
1
1
5
8
2
12
9
12
6
2
6
2
5
2
14
0.023
0.039
0.016
8.280
0.006
0.001
0.001
0.005
0.011
0.013
0.050
0.000
0.014
0.001
0.005
0.002
0.019
0.023
0.039
0.016
8.280
0.077
0.067
0.002
11.900
0.213
1.990
0.754
0.002
0.230
0.002
0.024
0.021
1.420
0.023
0.039
0.016
8.280
0.038
0.025
0.002
1.013
0.101
0.299
0.418
0.001
0.085
0.002
0.012
0.012
0.492
0.023
0.039
0.016
8.280
0.021
0.014
0.002
0.015
0.110
0.126
0.398
0.001
0.047
0.002
0.006
0.012
0.400
CONVENTIONAL POLLUTANTS
OIL AND GREASE
TOTAL SUSPENDED SOLIDS
11
14
11
13
34.000
3.000
2700.000
280.000
630.091
91.538
44.000
68.000
NONCONVENTIONAL ORGANIC POLLUTANTS
2-PROPANONE
ALPHA-TERPINEOL
BENZYL ALCOHOL
N-DODECANE
N-HEXADECANE
N-TETRACOSANE
N-TETRADECANE
TRICHLOROFLUOROMETHANE
2
2
2
2
2
2
2
2
1
2
2
2
2
1
2
1
0.321
65.300
2.729
12.316
46.591
17.002
153.020
0.036
0.321
67.324
24.800
20.200
52.700
17.002
160.000
0.036
0.321
66.312
13.765
16.258
49.645
17.002
156.510
0.036
0.321
66.312
13.765
16.258
49.645
17.002
156.510
0.036
(a)This table presents data only for pollutants that were detected in these wastewaters during the MP&M sampling program. In addition to the
pollutants listed, 80 priority organic and 141 nonconventional organic pollutants were analyzed for in five samples and not detected.
6-18
-------
Table 6-5 (Continued)
Analytical Data for Rinses Generating Oil-Bearing Wastewater(a)
Pollutant Parameter
No. of
Samples
Analyzed
No. of
Detects
Min. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean Detected
Concentration
(mg/L)
Median Detected
Concentration
(mg/L)
NONCONVENTIONAL METAL POLLUTANTS
ALUMINUM
BARIUM
BORON
CALCIUM
COBALT
IRON
MAGNESIUM
MANGANESE
MOLYBDENUM
SODIUM
TIN
TITANIUM
VANADIUM
YTTRIUM
14
14
14
14
14
14
14
14
14
14
14
14
14
14
9
13
12
14
4
13
14
13
8
14
9
9
3
3
0.055
0.002
0.019
0.940
0.007
0.067
0.137
0.004
0.010
3.840
0.030
0.003
0.007
0.002
7.970
0.740
290.000
114.000
0.011
19.560
20.700
0.802
0.076
1860.000
0.056
0.054
0.010
0.020
1.891
0.181
24.437
29.062
0.010
4.251
8.476
0.192
0.031
192.338
0.042
0.015
0.009
0.008
0.190
0.071
0.206
20.312
0.010
1.030
10.555
0.076
0.019
45.400
0.036
0.007
0.010
0.003
OTHER NONCONVENTIONAL POLLUTANTS
ACIDITY
TOTAL ALKALINITY
AMMONIA AS NITROGEN
CHEMICAL OXYGEN DEMAND
CHLORIDE
FLUORIDE
SULFATE
TOTAL DISSOLVED SOLIDS
TOTAL KJELDAHL NITROGEN
TOTAL PHOSPHORUS
TOTAL RECOVERABLE PHENOLICS
10
10
4
7
10
10
10
14
4
5
8
6
10
4
7
10
10
10
14
3
5
7
1.000
18.000
0.020
212.000
3.000
0.100
12.000
34.000
0.360
0.060
0.020
25.000
3800.000
0.870
11560.000
300.000
0.860
643.390
2300.000
6.300
11.000
0.800
11.500
535.900
0.352
2064.429
44.950
0.536
133.013
744.929
2.887
4.026
0.347
11.000
126.500
0.260
340.000
19.350
0.600
71.500
693.000
2.000
2.160
0.160
Source: MP&M Sampling Program.
(a)This table presents data only for pollutants that were detected in these wastewaters during the MP&M sampling program. In addition to the
pollutants listed, 80 priority organic and 141 nonconventional organic pollutants were analyzed for in five samples and not detected.
6-19
-------
Table 6-6
Pollutant Parameters Identified in the MP&M Data Collection Portfolios
for Oil-Bearing Unit Operations and Associated Rinses
Pollutant Parameter
No. of "Known to be Present"
Responses
No. of "Believed to be Present"
Responses
PRIORITY POLLUTANTS
BENZENE
CARBON TETRACHLORIDE
1,2-DICHLOROETHANE
1,1,1-TRICHLOROETHANE
HEXACHLOROETHANE
1,1-DICHLOROETHANE
1,1,2-TRICHLOROETHANE
1,1,2,2-TETRACHLOROETHANE
4-CHLORO-3-METHYLPHENOL
CHLOROFORM
1,2-DICHLOROBENZENE
2,4-DIMETHYLPHENOL
ETHYLBENZENE
FLUORANTHENE
METHYLENE CHLORIDE
CHLOROMETHANE
NAPHTHALENE
PHENOL
BIS(2-ETHYLHEXYL) PHTHALATE
DI-N-BUTYL PHTHALATE
TETRACHLOROETHENE
TOLUENE
TRICHLOROETHENE
ANTIMONY
ARSENIC
BERYLLIUM
CADMIUM
CHROMIUM
2
2
3
37
0
2
1
0
0
0
1
1
1
0
7
2
5
6
3
0
5
7
10
1
7
1
30
60
2
0
1
40
1
1
2
2
1
2
0
0
3
1
8
1
10
2
1
2
7
8
7
6
2
9
16
33
6-20
-------
Table 6-6 (Continued)
Pollutant Parameters Identified in the MP&M Data Collection Portfolios
for Oil-Bearing Unit Operations and Associated Rinses
Pollutant Parameter
No. of "Known to be Present"
Responses
No. of "Believed to be Present"
Responses
PRIORITY POLLUTANT POLLUTANTS (Continued)
COPPER
CYANIDE
LEAD
MERCURY
NICKEL
SELENIUM
SILVER
THALLIUM
ZINC
65
6
48
4
71
4
21
1
56
32
2
25
0
39
4
12
0
26
NONCONVENTIONAL ORGANIC POLLUTANTS
1,4-DIOXANE
2-BUTANONE
2-PROPANONE
4-METHYL-2-PENTANONE
O-CRESOL
P-CRESOL
STY RENE
0
7
4
4
3
3
1
3
6
12
4
1
0
0
NONCONVENTIONAL METAL POLLUTANTS
BARIUM
5
3
Source: MP&M DCPs.
6-21
-------
Table 6-7
Pollutant Parameters Identified in the MP&M Data Collection Portfolios
for Chelated Metal-Bearing Unit Operations and Associated Rinses
Pollutant Parameter
No. of "Known to be Present"
Responses
No. of "Believed to be Present"
Responses
PRIORITY POLLUTANTS
CHLOROFORM
ARSENIC
CADMIUM
CHROMIUM
COPPER
CYANIDE
LEAD
NICKEL
SELENIUM
SILVER
ZINC
1
1
2
2
6
5
2
12
1
4
5
0
0
0
0
0
1
0
1
0
0
1
Source: MP&M DCPs.
6-22
-------
Table 6-8
Analytical Data for Wastewater from
Unit Operations Generating Metal-Bearing Wastewater(a)
Pollutant Parameter
No. of
Samples
Analyzed
No. of
Detects
Min. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean Detected
Concentration
(mg/L)
Median Detected
Concentration
(mg/L)
PRIORITY POLLUTANTS
BENZENE
2,4-DINITROTOLUENE
2,6-DINITROTOLUENE
ETHYLBENZENE
METHYLENE CHLORIDE
NITROBENZENE
2-NITROPHENOL
2,4-DINITROPHENOL
N-NITROSODIMETHYLAMINE
PHENOL
DIBENZO(A,H)ANTHRACENE
TRICHLOROETHENE
ANTIMONY
ARSENIC
BERYLLIUM
CADMIUM
CHROMIUM
COPPER
CYANIDE
LEAD
MERCURY
NICKEL
SELENIUM
SILVER
THALLIUM
ZINC
9
9
9
9
9
9
9
9
9
9
9
9
143
143
143
143
143
143
13
143
143
143
143
143
143
142
1
2 j
2
1
3
1
1
2
2
2
1
1
80
91
68
106
130
131
12
93
75
123
65
91
54
132
0.019
22.400
6.670
0.020
0.011
0.119
2.290
235.000
6.170
0.120
0.034
0.015
0.002
0.001
0.001
0.003
0.006
0.005
0.003
0.044
0.000
0.014
0.001
0.005
0.002
0.008
0.019
24.400
7.280
0.020
6.759
0.119
2.290
434.000
7.170
34.287
0.034
0.015
12.600
18.000
3.870
57100.000
108000.000
36900.000
0.170
7150.000
0.045
84623.000
8.130
2.855
5.060
12200.000
0.019
23.400
6.975
0.020
2.267
0.119
2.290
334.500
6.670
17.203
0.034
0.015
0.605
0.772
0.191
554.661
1736.286
373.071
0.058
145.651
0.004
2412.302
0.281
0.187
0.130
383.309
0.019
23.400
6.975
0.020
0.030
0.119
2.290
334.500
6.670
17.203
0.034
0.015
0.051
0.021
0.006
0.067
1.355
2.540
0.050
0.834
0.001
1.400
0.020
0.021
0.020
2.265
CONVENTIONAL POLLUTANTS
OIL AND GREASE
TOTAL SUSPENDED SOLIDS
133
141
120
134
0.250
1.000
780,000.000
110,000.000
6622.441
1476.056
4.500
83.000
(a)This table presents data only for pollutants that were detected in these wastes during the MP&M sampling program. In addition to the pollutants
listed. 72 priority organic and 133 nonconventional organic pollutants were analyzed in nine samples and not detected.
6-23
-------
Table 6-8 (Continued)
Analytical Data for Wastewater from
Unit Operations Generating Metal-Bearing Wastewater(a)
Pollutant Parameter
No. of
Samples
Analyzed
No. of
Detects
Min. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean Detected
Concentration
(mg/L)
Median Detected
Concentration
(mg/L)
NONCONVENTIONAL ORGANIC POLLUTANTS
1,4-DINITROBENZENE
2-BUTANONE
2-HEXANONE
2-PROPANONE
4-METHYL-2-PENTANONE
ALPHA-TERPINEOL
BENZOIC ACID
HEXANOIC ACID
M-XYLENE
N,N-DIMETHYLFORMAMIDE
N-DECANE
N-DODECANE
0 + PXYLENE
P-CRESOL
P-NITROANILINE
TRICHLOROFLUOROMETHANE
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
2
4
1
6
2
1
3
2
1
1
1
1
1
1
1
1
1.070
0.223
5.016
0.084
0.124
0.035
5.500
5.880
0.020
0.028
3.514
1.272
0.910
0.010
26.100
0.106
3.920
38.300
5.016
11.900
1.154
0.035
91.249
19.300
0.020
0.028
3.514
1.272
0.910
0.010
26.100
0.106
2.495
11.936
5.016
3.917
0.639
0.035
49.883
12.590
0.020
0.028
3.514
1.272
0.910
0.010
26.100
0.106
2.495
4.610
5.016
0.643
0.639
0.035
52.900
12.590
0.020
0.028
3.514
1.272
0.910
0.010
26.100
0.106
NONCONVENTIONAL METAL POLLUTANTS
ALUMINUM
BARIUM
BORON
CALCIUM
COBALT
IRON
MAGNESIUM
MANGANESE
MOLYBDENUM
SODIUM
TIN
TITANIUM
143
143
143
143
143
143
143
143
143
143
143
143
114
113
125
137
88
131
123
119
113
141
86
93
0.041
0.003
0.010
0.804
0.005
0.011
0.152
0.002
0.009
1.250
0.030
0.003
34900.000
70.078
7090.000
1935.700
225.000
374000.000
1100.000
4790.000
197.000
383000.000
44000.000
14300.000
1156.526
1.475
281.202
93.160
7.709
5932.148
74.099
80.586
4.572
14177.100
889.976
374.890
5.214
0.100
0.872
35.900
0.372
8.140
16.500
0.291
0.230
341.000
0.333
0.165
(a)This table presents data only for pollutants that were detected in these wastes during the MP&M sampling program. In addition to the pollutants
listed, 72 priority organic and 133 nonconventional organic pollutants were analyzed in nine samples and not detected.
6-24
-------
Table 6-8 (Continued)
Analytical Data for Wastewater from
Unit Operations Generating Metal-Bearing Wastewater(a)
Pollutant Parameter
No. of
Samples
Analyzed
No. of
Detects
Min. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean Detected
Concentration
(mg/L)
Median Detected
Concentration
(mg/L)
NONCONVENTIONAL METAL POLLUTANTS (Continued)
VANADIUM
YTTRIUM
143
143
85
69
0.004
0.001
1540.000
0.900
38.967
0.057
0.046
0.008
OTHER NONCONVENTIONAL POLLUTANTS
ACIDITY
TOTAL ALKALINITY
AMMONIA AS NITROGEN
CHEMICAL OXYGEN DEMAND
CHLORIDE
FLUORIDE
SULFATE
TOTAL DISSOLVED SOLIDS
TOTAL KJELDAHL NITROGEN
TOTAL PHOSPHORUS
TOTAL RECOVERABLE
PHENOLICS
127
128
49
71
132
132
132
141
51
48
54
84
106
45
68
109
121
122
139
49
43
42
1.000
1.000
0.060
5.000
1.000
0.100
1.000
27.000
0.480
0.020
0.004
650000.000
890000.000
43000.000
600000.000
316000.000
57000.000
755000.000
1000000.00
40000.000
11000.000
135.000
67034.746
50284.962
2052.480
23232.199
6933.957
1400.536
26376.491
97188.288
2474.514
760.100
8.561
450.000
409.000
8.600
2050.000
75.000
2.500
135.000
14000.000
14.190
7.500
0.620
Source: MP&M Sampling Program.
(a)This table presents data only for pollutants that were detected in these wastes during the MP&M sampling program. In addition to the pollutants
listed, 72 priority organic and 133 nonconventional organic pollutants were analyzed in nine samples and not detected.
6-25
-------
Table 6-9
Analytical Data for Wastewater from
Rinses Generating Metal-Bearing Wastewater
Pollutant Parameter
No. of Samples
Analyzed
No. of Detects
Mm. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean Detected
Concentration
(mg/L)
Median Dete
Concentrati
(mg/L)
PRIORITY POLLUTANTS
ANTIMONY
ARSENIC
BERYLLIUM
CADMIUM
CHROMIUM
COPPER
CYANIDE
LEAD
MERCURY
NICKEL
SELENIUM
SILVER
THALLIUM
ZINC
157
157
157
157
157
157
9
157
157
157
157
157
157
157
69
77
64
100
132
147
9
77
75
129
71
97
63
128
0.002
0.001
0.001
0.002
0.007
0.003
0.010
0.020
0.000
0.010
0.001
0.004
0.001
0.008
0.083
0.090
0.059
6.930
105.000
100.000
1.500
6.820
0.004
300.430
0.196
0.097
0.039
177.000
0.017
0.011
0.004
0.205
2.630
2.248
0.422
0.287
0.000
10.256
0.013
0.011
0.007
5.487
O.C
0.0
0.0
0.0
0.1
0.0
0.0
0.0
0.0
0.0
0.0
O.Oi
O.Oi
0.1
CONVENTIONAL POLLUTANTS
OIL AND GREASE
TOTAL SUSPENDED SOLIDS
113
156
99
134
0.280
2.000
110.000
1200.000
9.885
69.033
2.5(
14.0(
NONCONVENTIONAL METAL POLLUTANTS
ALUMINUM
BARIUM
BORON
CALCIUM
COBALT
IRON
MAGNESIUM
MANGANESE
MOLYBDENUM
SODIUM
TIN
TITANIUM
157
157
157
157
157
157
157
157
157
157
157
157
115
119
137
156
69
147
150
125
96
157
86
75
0.031
0.001
0.010
0.033
0.008
0.016
0.416
0.001
0.006
0.277
0.015
0.002
76.900
1.600
21.791
204.000
11.000
2830.000
26.000
23.300
13.400
19700.000
4.667
18.100
1.995
0.076
0.657
39.264
0.456
60.132
10.395
1.164
0.282
462.302
0.163
0.780
0.2<
O.fr
o.i;
25.6<
0.01
0.2"
10.95
0.01
0.01
48.90
0.03
0.00
6-26
-------
Table 6-9 (Continued)
Analytical Data for Wastewater from
Rinses Generating Metal-Bearing Wastewater
Pollutant Parameter
No. of Samples
Analyzed
No. of Detects
Min. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean Detected
Concentration
(mg/L)
Median Detected
Concentration
(mg/L)
NONCONVENTIONAL METAL POLLUTANTS (Continued)
VANADIUM
YTTRIUM
157
157
71
67
0.005
0.001
1.100
0.025
0.066
0.003
0.010
0.003
OTHER NONCONVENTIONAL POLLUTANTS
ACIDITY
TOTAL ALKALINITY
AMMONIA AS NITROGEN
CHEMICAL OXYGEN DEMAND
CHLORIDE
FLUORIDE
SULFATE
TOTAL DISSOLVED SOLIDS
TOTAL KJELDAHL NITROGEN
TOTAL PHOSPHORUS
TOTAL RECOVERABLE
PHENOLICS
99
100
26
43
104
104
104
156
35
32
37
70
91
19
39
103
99
104
156
33
30
27
1.000
1.000
0.100
6.000
1.200
0.100
1.000
20.000
0.100
0.020
0.006
180000.000
8600.000
31.000
2500.000
65000.000
140.000
6200.000
120000.000
27.000
750.000
16.000
3550.297
427.679
2.105
219.605
1336.952
5.751
144.663
2497.577
2.930
67.534
0.628
11.550
72.000
0.360
53.000
24.000
0.920
48.500
410.000
1.000
1.850
0.010
Source: MP&M Sampling Program.
6-27
-------
Table 6-10
Pollutant Parameters Identified in the MP&M Data Collection Portfolios for
Metal-Bearing Unit Operations and Associated Rinses
Pollutant Parameter
No. of "Known to be Present"
Responses
No. of "Believed to be Present"
Responses
PRIORITY POLLUTANTS
ACRYLONITRILE
BENZENE
CARBON TETRACHLORIDE
CHLOROBENZENE
HEXACHLOROBENZENE
1,2-DICHLOROETHANE
1,1,1-TRICHLOROETHANE
HEXACHLO ROETHANE
4-CHLORO-3-METHYLPHENOL
CHLOROFORM
ETHYLBENZENE
METHYLENE CHLORIDE
CHLOROMETHANE
ISOPHORONE
NAPHTHALENE
PHENOL
BIS(2-ETHYLHEXYL) PHTHALATE
DI-N-BUTYL PHTHALATE
DI-N-OCTYL PHTHALATE
DIMETHYL PHTHALATE
ANTHRACENE
DIBENZO(A,H)ANTHRACENE
TETRACHLOROETHENE
TOLUENE
TRICHLOROETHENE
VINYL CHLORIDE
ANTIMONY
ARSENIC
BERYLLIUM
CADMIUM
1
11
0
1
0
0
5
0
0
2
7
9
0
1
2
11
1
0
0
1
1
0
1
37
3
0
3
8
1
37
0
4
1
1
1
1
16
1
1
0
13
20
1
0
6
4
1
1
1
0
0
1
0
51
2
1
7
4
5
13
6-28
-------
Table 6-10 (Continued)
Pollutant Parameters Identified in the MP&M Data Collection Portfolios for
Metal-Bearing Unit Operations and Associated Rinses
Pollutant Parameter
No. of "Known to be Present"
Responses
No. of "Believed to be Present"
Responses
PRIORITY POLLUTANTS (Continued)
CHROMIUM
COPPER
CYANIDE
LEAD
MERCURY
NICKEL
SELENIUM
SILVER
THALLIUM
ZINC
95
95
22
84
11
106
6
36
2
82
29
26
6
38
4
24
7
18
0
25
NONCONVENTIONAL ORGANIC POLLUTANTS
2-BUTANONE
2-PROPANONE
4-METHYL-2-PENTANONE
ISOBUTYL ALCOHOL
0-CRESOL
STY RENE
14
12
6
4
1
1
41
29
22
6
0
4
NONCONVENTIONAL METAL POLLUTANTS
BARIUM
15
2
Source: MP&M DCPs.
6-29
-------
Table 6-11
Pollutant Parameters Identified in the MP&M Data Collection Portfolios
for Unidentified Unit Operations
Pollutant Parameter
No. of "Known to be Present"
Responses
No. of "Believed to be Present"
Responses
PRIORITY POLLUTANTS
ACENAPHTHENE
ACROLEIN
ACRYLONITRILE
BENZENE
BENZIDINE
CARBON TETRACHLORIDE
CHLOROBENZENE
1,2,4-TRICHLOROBENZENE
HEXACHLO ROBENZENE
1 ,2-DICHLO ROETHANE
1,1,1-TRICHLOROETHANE
HEXACHLOROETHANE
1,1-DICHLOROETHANE
1,1,2-TRICHLOROETHANE
1,1,2,2-TETRACHLOROETHANE
CHLO ROETHANE
BIS(2-CHLOROETHYL) ETHER
2-CHLOROETHYLVINYL ETHER
2-CHLO RONAPHTHALENE
2,4,6-TRICHLOROPHENOL
CHLOROFORM
1 ,2-DICHLO ROBENZENE
1,3-DICHLOROBENZENE
1,4-DICHLOROBENZENE
3,3'-DICHLOROBENZIDINE
1,1-DICHLOROETHENE
TRANS-1,2-DICHLOROETHENE
2,4-DICHLOROPHENOL
1
2
2
4
1
5
4
2
1
4
11
2
4
2
2
2
1
1
1
1
16
2
2
3
1
4
2
2
0
0
0
6
0
1
0
0
0
0
9
0
0
0
0
0
0
0
0
0
3
1
0
0
0
0
0
0
6-30
-------
Table 6-11 (Continued)
Pollutant Parameters Identified in the MP&M Data Collection Portfolios
for Unidentified Unit Operations
Pollutant Parameter
No. of "Known to be Present"
Responses
No. of "Believed to be Present"
Responses
PRIORITY POLLUTANTS (Continued)
1,2-DICHLOROPROPANE
TRANS-1,3-DICHLOROPROPENE
2,4-DIMETHYLPHENOL
2,4-DINITROTOLUENE
2,6-DINITROTOLUENE
ETHYLBENZENE
FLUORANTHENE
4-CHLOROPHENYL PHENYL ETHER
4-BROMOPHENYL PHENYL ETHER
BIS(2-CHLOROISOPROPYL) ETHER
BIS(2-CHLOROETHOXY) METHANE
METHYLENE CHLORIDE
CHLOROMETHANE
BROMOMETHANE
TRIBROMOMETHANE
BROMODICHLOROMETHANE
DIBROMOCHLOROMETHANE
HEXACHLOROBUTADIENE
ISOPHORONE
NAPHTHALENE
NITROBENZENE
2-NITROPHENOL
4-NITROPHENOL
2,4-DINITROPHENOL
N-NITROSODIMETHYLAMINE
N-NITROSODIPHENYLAMINE
N-NITROSODI-N-PROPYLAMINE
PENTACHLOROPHENOL
2
1
1
2
1
6
1
1
1
1
1
9
1
1
3
6
3
2
1
2
1
1
1
1
1
1
1
2
0
0
0
0
0
0
0
0
0
0
0
3
1
0
1
0
0
0
0
2
0
0
0
0
0
0
0
0
6-31
-------
Table 6-11 (Continued)
Pollutant Parameters Identified in the MP&M Data Collection Portfolios
for Unidentified Unit Operations
Pollutant Parameter
No. of "Known to be Present"
Responses
No. of "Believed to be Present"
Responses
PRIORITY POLLUTANTS (Continued)
PHENOL
BIS(2-ETHYLHEXYL) PHTHALATE
BUTYL BENZYL PHTHALATE
DI-N-BUTYL PHTHALATE
DI-N-OCTYL PHTHALATE
DIETHYL PHTHALATE
DIMETHYL PHTHALATE
BENZO(A)ANTHRACENE
BENZO(A)PYRENE
BENZO(B)FLUORANTHENE
BENZO(K)FLUORANTHENE
CHRYSENE
ACENAPHTHYLENE
BENZO(GHI)PERYLENE
FLUORENE
PHENANTHRENE
DIBENZO(A,H)ANTHRACENE
INDENO(1,2,3-CD)PYRENE
PYRENE
TETRACHLO ROETHENE
TOLUENE
TR1CHLOROETHENE
VINYL CHLORIDE
ANTIMONY
ARSENIC
BERYLLIUM
CADMIUM
CHROMIUM
COPPER
8
5
2
1
1
1
1
1
2
1
1
1
1
1
1
1
2
1
1
6
9
5
4
3
10
1
32
32
37
4
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
2
4
2
0
4
2
3
8
15
17
6-32
-------
Table 6-11 (Continued)
Pollutant Parameters Identified in the MP&M Data Collection Portfolios
for Unidentified Unit Operations
Pollutant Parameter
No. of "Known to be Present"
Responses
No. of "Believed to be Present"
Responses
PRIORITY POLLUTANTS (Continued)
CYANIDE
LEAD
MERCURY
NICKEL
SELENIUM
SILVER
THALLIUM
ZINC
28
35
13
33
15
26
4
41
0
12
2
18
1
4
0
11
NONCONVENTIONAL ORGANIC POLLUTANTS
2-CHLOROPHENOL
1,2,4,5-TETRACHLOROBENZENE
1,2-DIBROMOETHANE
2,3,4,6-TETRACHLOROPHENOL
2-BUTANONE
2-PROPANONE
3-METHYLCHOLANTHRENE
4-METHYL-2-PENTANONE
ANILINE
CARBON DISULFIDE
DIPHENYLAMINE
ISOBUTYL ALCOHOL
O-CRESOL
P-CRESOL
PENTACHLO ROBENZENE
PYRIDINE
STY RENE
1
0
0
0
9
9
0
2
0
1
0
0
1
1
0
1
1
0
1
1
1
5
6
1
1
1
1
1
2
0
0
1
1
3
NONCONVENTIONAL METAL POLLUTANTS
BARIUM
9
5
Source: MP&M DCPs.
6-33
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Table 6-12
Analytical Data for Chemical Precipitation and Sedimentation Influent(a)
Pollutant Parameter
No. of
Samples
Analyzed
No. of
Detects
Mm. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean
Detected
Concentration
(mg/L)
Median
Detected
Concentratio
(mg/L)
PRIORITY POLLUTANTS
1,1,1-TRICHLOROETHANE
CHLOROFORM
METHYLENE CHLORIDE
BROMODICHLOROMETHANE
NAPHTHALENE
PHENOL
BIS(2-ETHYLHEXYL) PHTHALATE
FLUORENE
PHENANTHRENE
TETRACHLOROETHENE
ANTIMONY
ARSENIC
BERYLLIUM
CADMIUM
CHROMIUM
COPPER
CYANIDE
LEAD
MERCURY
NICKEL
SELENIUM
SILVER
THALLIUM
ZINC
11
11
11
11
11
11
11
11
11
11
58
62
62
62
62
62
23
62
60
62
58
62
58
62
2
2
1
2
1
5
6
1
1
2
16
31
19
42
61
62
18
27
9
56
8
34
2
55
0.019
0.060
0.172
0.016
0.010
0.042
0.011
0.010
0.012
1.007
0.003
0.002
0.000
0.006
0.006
0.030
0.015
0.051
0.000
0.030
0.003
0.007
0.003
0.029
0.084
0.413
0.172
0.027
0.010
0.634
0.172
0.010
0.012
1.107
0.367
0.530
0.355
27.000
1,350.000
125.000
21.100
159.000
0.012
608.000
0.090
4.230
0.006
100.470
0.052
0.236
0.172
0.021
0.010
0.213
0.108
0.010
0.012
1.057
0.043
0.034
0.067
2.098
30.831
7.438
2.495
6.344
0.002
43.656
0.029
0.292
0.004
11.956
0.052
0.236
0.172
0.021
0.010
0.115
0.134
0.010
0.012
1.057
0.010
0.010
0.019
0.191
3.060
0.554
0.269
0.251
0.000
0.933
0.021
0.047
0.004
0.801
CONVENTIONAL POLLUTANTS
OIL AND GREASE
TOTAL SUSPENDED SOLIDS
56
62
48
58
0.630
6.000
1,100.000
4,650.000
111.411
432.393
18.038
109.518
(a)This table presents data only for pollutants that were detected in these wastewaters during the MP&M sampling program. In addition to the pollutants
listed, 74 priority organic and 129 nonconventional organic pollutants were analyzed for in eleven samples and not detected.
6-34
-------
Table 6-12 (Continued)
Analytical Data for Chemical Precipitation and Sedimentation Influent(a)
Pollutant Parameter
NONCONVENTIONAL ORGANIC POLLUTANTS
1-METHYLFLUORENE
1-METHYLPHENANTH RENE
2-METHYLNAPHTHALENE
2-PROPANONE
ALPHA-TERPINEOL
BENZOIC ACID
CARBON DISULFIDE
DIBENZOFURAN
HEXANOIC ACID
N-DECANE
N-DODECANE
N-EICOSANE
N-HEXACOSANE
N-HEXADECANE
N-OCTADECANE
N-TETRACOSANE
N-TETRADECANE
N-TRIACONTANE
STY RENE
TRICHLOROFLUOROMETHANE
No. of
Samples
Analyzed
No. of
Detects
Min. Detected
Concentration
(mg/L)
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
2
2
3
10
2
4
1
1
2
3
4
4
2
5
4
2
4
1
1
4
0.012
0.015
0.011
0.056
0.013
0.104
0.545
0.018
0.010
0.011
0.017
0.018
0.016
0.017
0.012
0.011
0.016
0.026
0.188
0.031
Max. Detected
Concentration
(mg/L)
0.016
0.016
0.047
0.596
0.018
0.618
0.545
0.018
0.015
0.031
0.198
0.034
0.031
0.061
0.043
0.018
0.124
0.026
0.188
0.109
Mean
Detected
Concentration
(mg/L)
Median
Detected
Concentration
(mg/L)
0.014
0.015
0.027
0.212
0.016
0.255
0.545
0.018
0.013
0.018
0.096
0.022
0.024
0.037
0.028
0.015
0.057
0.026
0.188
0.051
0.014
0.015
0.023
0.091
0.016
0.150
0.545
0.018
0.013
0.013
0.084
0.019
0.024
0.035
0.028
0.015
0.044
0.026
0.188
0.033
NONCONVENTIONAL METAL POLLUTANTS
ALUMINUM
BARIUM
BORON
CALCIUM
COBALT
IRON
MAGNESIUM
MANGANESE
62
62
62
62
62
62
62
62
54
49
56
62
31
62
57
61
0.093
0.010
0.165
7.890
0.010
0.148
0.349
0.004
59.832
9.910
9.160
369.150
25.800
3,880.000
442.500
16.000
7.068
0.318
1.207
80.281
2.591
251.960
52.025
1.535
3.343
0.080
0.864
36.750
0.030
6.220
18.400
0.221
(a)This table presents data only for pollutants that were detected in these wastewaters during the MP&M sampling program. In addition to the pollutants
listed, 74 priority organic and 129 nonconventional organic pollutants were analyzed for in eleven samples and not detected.
6-35
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Table 6-12 (Continued)
Analytical Data for Chemical Precipitation and Sedimentation Influent(a)
Pollutant Parameter
No. of
Samples
Analyzed
No. of
Detects
Min. Detected
Concentration
(mg/L)
Max. Detected
Concentration
(mg/L)
Mean
Detected
Concentration
(mg/L)
Median
Detected
Concentratio
(mg/L)
NONCONVENTIONAL METAL POLLUTANTS (Continued)
MOLYBDENUM
SODIUM
TIN
TITANIUM
VANADIUM
YTTRIUM
62
62
62
62
62
62
41
62
26
44
18
20
0.008
15.600
0.026
0.003
0.006
0.002
1.600
3,470.000
1.710
1.690
0.160
0.085
0.184
479.535
0.460
0.149
0.049
0.010
0.058
214.500
0.230
0.038
0.019
0.005
OTHER NONCONVENTIONAL POLLUTANTS
ACIDITY
TOTAL ALKALINITY
AMMONIA AS NITROGEN
CHEMICAL OXYGEN DEMAND
CHLORIDE
FLUORIDE
SULFATE
TOTAL DISSOLVED SOLIDS
TOTAL KJELDAHL NITROGEN
TOTAL PHOSPHORUS
TOTAL RECOVERABLE PHENOLICS
57
58
53
56
59
59
59
62
53
52
51
37
36
49
52
55
58
58
62
50
51
28
3.000
2.390
0.021
18.000
12.000
0.130
40.000
19.000
0.110
0.180
0.007
24,770.135
510.000
150.000
14,000.000
9,500.000
29.000
6,125.000
34,000.000
120.000
525.000
20.000
2,106.192
157.995
11.814
1,575.374
416.810
3.191
496.585
3,408.351
16.341
36.760
1.909
210.000
133.000
1.780
380.000
150.000
1.631
292.500
991.000
6.690
10.000
0.024
Source: MP&M Sampling Program.
(a)This table presents data only for pollutants that were detected in these wastewaters during the MP&M sampling program. In addition to the pollutants
listed, 74 priority organic and 129 nonconventional organic pollutants were analyzed for in eleven samples and not detected.
6-36
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7.0 INDUSTRY SUBCATEGORIZATION
7.0 INDUSTRY SUBCATEGORIZATION
In developing technology-based regulations for Phase I of the Metal Products and
Machinery (MP&M) category, the Agency considered various factors to determine an
appropriate approach for subcategorization of the category. The Clean Water Act
requires EPA to assess several factors, including manufacturing processes, products, size
of site, geographic location, site age, water use practices, and wastewater characteristics.
For MP&M Phase I, the Agency also considered factors such as activity and nonwater
quality environmental impacts (e.g., energy usage, air emissions, solid waste generation).
As shown in this section, Phase I of the MP&M category is not characterized by sets of
unique core unit operations, raw materials, and wastewater characteristics that require
subcategorization. In addition, other factors considered, including economic impacts of
the proposed regulation, were not found to be the basis of subcategorization. Therefore,
EPA did not subcategorize the MP&M Phase I category.
Section 7.1 presents the factors considered for subcategorization of the MP&M Phase I
category. Sections 7.2 through 7.12 present discussions of each of these factors.
7.1 Factors Considered for Subcategorization
The factors considered for subcategorization were selected based on factors required by
the Clean Water Act and additional factors applicable to the MP&M Phase I industry.
These factors are:
• Unit operations (production processes);
• Activity;
• Raw materials;
• Products;
• Size of site;
• Geographic location;
• Age;
• Total energy requirements;
• Air pollution control methods;
• Solid waste generation and disposal;
• Economic impacts of the regulation;
• Water use practices; and
• Wastewater characteristics.
The remainder of this section discusses these factors. Water use practices and
wastewater characteristics are discussed throughout and are not presented under a
separate heading.
7-1
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7.0 INDUSTRY SUBCATEGORIZATION
7.2 Unit Operations
Within the MP&M Phase I category, 48 unit operations are typically performed along
with associated rinses. Many of these unit operations use and discharge process water.
As shown in Section 6.0, wastewaters generated by different unit operations have
different characteristics. For example, machining wastewaters typically contain high
concentrations of oil and grease, while electroplating wastewaters contain high
concentrations of metals. However, as shown by the analyses described in this section,
wastewater characteristics for any unit operation are expected to be similar across all
subcategorization factors, with the exception of raw materials (discussed in Section 7.4).
The unit operations are considered to be the building blocks, or subdivisions, within the
MP&M Phase I category.
The characteristics of wastewaters generated by the unit operations were used to identify
applicable in-process pollution prevention and end-of-pipe treatment technologies for
MP&M wastewaters. In the example above, machining wastewaters require oil/water
separation followed by chemical precipitation and sedimentation, while the electroplating
wastewaters may require chromium reduction or cyanide destruction (depending on the
type of electroplating performed) followed by chemical precipitation and sedimentation.
By using the unit operations as building blocks, EPA identified appropriate types of
in-process pollution prevention and end-of-pipe treatment technologies for MP&M sites,
based on the types of operations performed on site. These technologies were used to
estimate compliance costs (Section 12.0) and pollutant loadings and reductions
(Section 13.0).
7.3 Activity
MP&M Phase I sites performed one or more of the following activities: manufacturing,
rebuilding, and maintenance. These activities are defined below.
• Manufacturing is the series of unit operations necessary to produce
metal products. Manufacturing is generally performed in a
production environment.
• Rebuilding is the series of unit operations necessary to disassemble
used metal products into components, replace the components or
subassemblies or restore them to original function, and reassemble
the metal product. Rebuilding is generally performed in a
production environment.
• Maintenance is the series of unit operations, on original or
replacement components, required to keep metal products in
operating condition. Maintenance is generally performed in a non-
production environment.
7-2
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7.0 INDUSTRY SUBCATEGORIZATION
The Agency did not subcategorize by activity because the MP&M Phase I unit operations
are performed in the same manner and generate the same types of waste regardless of
activity.
Based on the data collection portfolio (DCP) results, the percentage of water-discharging
MP&M Phase I sites performing each of the activity combinations listed above are as
follows.
Percentage of Water-Discharging Sites
Performing Each Activity Combination
Activity
Percentage
Manufacturing Only
Rebuilding Only
Maintenance Only
Manufacturing and Rebuilding
Manufacturing and Maintenance
Rebuilding and Maintenance
Manufacturing, Rebuilding, and Maintenance
71
1
8
13
2
2
3
Source: MP&M Phase I DCP Database.
With the exception of the initial cleaning steps for rebuilding and maintenance (discussed
below), wastewater characteristics do not vary across activity. Results of analyses of the
DCP database indicate that the production-normalized flow rate (volume of wastewater
discharged per unit of production) for each unit operation does not depend on the
activity. EPA used the production-normalized flow rate to assess subcategorization
across activity because the amount of pollutant discharged from a MP&M unit operation
is related to the production rate through the unit operation. The ratio of wastewater
discharge rate to production rate influences the characteristics of wastewater generated
by the operation (i.e., pollutant concentrations in wastewater from a cleaning rinse with a
production-normalized flow of 2 gallons/square foot are expected to be approximately
twice as high as pollutant concentrations in wastewater from a cleaning rinse with
production-normalized flow of 4 gallons/square foot). Information collected during site
visits at MP&M Phase I sites supports these conclusions.
The initial cleaning steps associated with rebuilding and maintenance may have unique
wastewater characteristics because of the presence of oil and grease not present in
cleaning steps associated with manufacturing. Based on analytical data collected at
rebuilding sites, these wastewaters may require additional preliminary treatment capacity
7-3
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7.0 INDUSTRY SUBCATEGORIZATION
(e.g., oil/water separation), but do not impact the overall treatability of wastewater from
rebuilding sites. Therefore, EPA did not subcategorize based on these initial rebuilding
and maintenance cleaning steps. The impact of the oil and grease was accounted for in
the development of compliance cost estimates and pollutant loading estimates (discussed
in Sections 12.0 and 13.0, respectively).
7.4 Raw Materials
Raw materials at MP&M Phase I sites consist of base metals processed (e.g., bar stock,
sheet stock, ingots, formed parts) and applied materials (e.g., paint; corrosion preventive
coating; metal applied during electroplating, electroless plating, and metal spraying).
Data from the DCP database and engineering site visits indicate that the wastewater
discharge rates from unit operations are not dependent on the base metal processed or
material applied. The base metal or material applied affects the site's wastewater
characteristics. For example, a site processing only copper will have higher
concentrations of copper than other metals, while a site processing steel and nickel and
performing zinc electroplating will have higher concentrations of iron, nickel, and zinc
than other metals. However, the impact on wastewater characteristics was accounted for
in calculating technology effectiveness concentrations (discussed in Section 11.0) and
pollutant loading estimates (discussed in Section 13.0).
More than half of the DCP respondents process more than one base metal type. Based
on the DCP results, the percentage of water-discharging MP&M Phase I sites by the
number of metal types processed are shown in the following table.
Percentage of Water-Discharging Sites
by Number of Metal Types Processed
One metal type
Two metal types
Three metal types
Four metal types
Five or more metal types
43%
'o
32%
15%
'o
4%
6%
Source: MP&M DCP Phase I Database.
Based on DCP results, 24 different metal types were identified as processed at MP&M
Phase I sites. Sites also periodically change metal types. At sites processing multiple
metal types, individual unit operations frequently process more than one metal type (e.g.,
a machining operation can process nickel, aluminum, and iron parts). Additionally, not
all metal types processed at a site are processed through all unit operations. For
7-4
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7.0 INDUSTRY SUBCATEGORIZATION
example, a site may process aluminum and iron base metals. Anodizing is performed on
the aluminum, and zinc electroplating on the iron. Both metals share the same alkaline
and acid treatments. Subcategorizing by base metal type would place the anodizing
operation in the aluminum subcategory, the electroplating operation in either the zinc or
iron subcategory, and the alkaline and acid treatments in both the aluminum and iron
subcategories. The Agency did not subcategorize by base metal or material applied
because the wastewater discharge rates from unit operations are not dependent on base
metal or material applied. The effect of base metal or material applied on wastewater
characteristics was accounted for in calculating pollutant loadings and technology
effectiveness concentrations.
7.5 Products
The MP&M Phase I category is divided into seven industrial sectors: aerospace, aircraft,
electronic equipment, hardware, mobile industrial equipment, ordnance, and stationary
industrial equipment. The sector determination reflects the products manufactured at
the site. Table 3-1 lists the types of products typically processed within each of the
sectors. An analysis by sector therefore includes an analysis of products manufactured,
rebuilt, or maintained at MP&M sites. The Agency did not subcategorize by product,
because no unique sets of unit operations and wastewater characteristics were identified
by product, and the unit operations are not performed differently across sector. These
reasons are discussed below.
A review of the DCP database and site visit information indicates that no core sets of
unit operations exist for any sector. Most MP&M unit operations are not unique to a
particular sector, and are performed across all sectors. Based on the DCP database, the
most frequently performed wastewater-generating unit operations (e.g., acid treatment,
alkaline treatment, chemical conversion coating, grinding, machining) are performed in
all sectors. The unit operations that are rarely performed (e.g., abrasive jet machining)
are not performed in all sectors, but are also not limited to a single sector. Based on
information obtained from site visits and sampling episodes, the less common unit
operations do not affect the overall treatability of wastewaters generated at sites
performing these unit operations. Because the major wastewater-generating unit
operations are performed across all sectors, and other unit operations performed in
specific sectors do not affect treatability, raw wastewaters have similar treatability across
MP&M Phase I sectors.
The Agency collected analytical data from sites within each of the seven Phase I sectors.
A review of these data indicate that the wastewater characteristics do not vary
significantly across sectors.
EPA reviewed the DCP database to assess if unit operations are performed differently
across sectors. EPA used the production-normalized flow (wastewater discharge rate per
unit of production) as an indicator to assess water use practices across sectors. The
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7.0 INDUSTRY SUBCATEGORIZATION
review of the DCP database indicates that the production-normalized flow rate for an
operation is not dependent on sector. For example, a site performing nickel
electroplating of stationary industrial equipment components can achieve the same
production-normalized flow rate (and therefore would have similar wastewater
characteristics) as another site performing a similar nickel electroplating operation for
aerospace components.
7.6 Size of Site
EPA used the following parameters as relative measures of the size of MP&M sites:
number of employees, wastewater discharge flow rate, and production rate. An
assessment of these parameters as a basis for subcategorization is presented below.
7.6.1 Number of Employees
Raw materials, unit operations, and wastewater characteristics are independent of the
number of site employees. A review of the DCP database shows that production-
normalized flows do not depend on the number of employees. A correlation between
the number of employees and wastewater generation is difficult to develop due to
variations in staff. Fluctuations can occur for many reasons, including shift differences,
clerical and administrative support, maintenance workers, efficiency of site operations,
degree of automation, and market fluctuations. For these reasons, the Agency did not
subcategorize by number of employees.
7.6.2 Wastewater Discharge Flow Rate
The Agency did not subcategorize by site wastewater discharge flow rate because the
wastewater characteristics for a site are independent of the overall wastewater discharge
flow rate from a site. Wastewater characteristics are primarily a function of the raw
materials, unit operations, and water use practices at a site, and not the site's overall
wastewater discharge flow rate. For example, a site performing one machining operation
on steel and discharging 100 gallons per year of wastewater would have similar
wastewater characteristics as a site performing 1,000 machining operations on steel and
discharging 100,000 gallons per year, provided the sites have similar water use practices.
A review of the DCP database shows that water use practices, as measured by
production-normalized flow rates, do not depend on the overall wastewater discharge
flow rate from a site. The raw materials and unit operations also do not vary by overall
site discharge flow rate.
For indirect discharges (sites discharging to publicly owned treatment works (POTWs))
EPA developed a regulatory implementation scheme based on wastewater discharge flow
rate. This is discussed in Sections 10.0 and 15.0. Existing indirect dischargers with
annual process water discharge flow rates of less than one million gallons are exempt
from the MP&M Phase I pretreatment standards. All other indirect dischargers are
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7.0 INDUSTRY SUBCATEGORIZATION
required to comply with mass-based standards. This scheme was developed to facilitate
implementation of this regulation, and not as a means to subcategorize the MP&M
Phase I category.
7.6.3 Production Rate
The Agency did not subcategorize by site production rate because the production rate
through a MP&M Phase I site does not reflect the production rate through process
wastewater-generating unit operations, and the production-normalized flow for an
operation does not depend on the overall production rate for the site. For example,
three sites may each process 100 tons of steel annually. One site may process all of the
steel through an electroplating line, the second may perform dry assembly for 95 tons
and process 5 tons through a machining operation, and the third may process 40 tons
through an electroplating line, 40 tons through a machining operation, and 20 tons
through dry assembly. All three sites would be expected to have different wastewater
discharge rates and wastewater characteristics. However, the production-normalized flow
rates and hence the wastewater characteristics for electroplating at the first and third
sites would be expected to be similar, whereas the production-normalized flow rates for
the machining operations at the second and third sites would be expected to be similar.
Because the wastewater characteristics depend on the unit operations performed, and not
the overall production rate for the site, EPA did not subcategorize by site production
rate.
7.7 Geographical Location
MP&M Phase I sites are located throughout the United States. Sites are not limited to
any one geographical location, but approximately two-thirds are located east of the
Mississippi, with additional concentrations of sites in Texas and California. EPA did not
subcategorize based on geographical location because location does affect the ability of
sites to comply with the MP&M Phase I rulemaking.
Geographical location may impact costs if additional land is required to install treatment
systems, since the cost of the land will vary depending on whether the site is located in
an urban or rural location. The treatment systems used to treat MP&M wastewaters
typically do not have large land requirements, as demonstrated by the fact that many
MP&M Phase I sites are located in urban settings. Therefore, the Agency did not
subcategorize based on land availability.
Water availability is another function of geographical location. Limited water supply
encourages conservation by efficient use of water, including recycle and reuse.
Therefore, insufficient water availability encourages the early installation of practices
advisable for the entire category to reduce treatment costs and improve pollutant
removals.
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7.0 INDUSTRY SUBCATEGORIZATION
7.8 Age
The percentage of water-discharging sites by the decade in which they were built is listed
below. This information is based upon the DCP respondents that reported the date their
site was built.
Percentage of Wastewater-Discharging Sites by Decade Built
Decade Built
Before 1920
1920 through 1929
1930 through 1939
1940 through 1949
1950 through 1959
1960 through 1969
1970 through 1979
1980 through 1989
1990(a)
Percentage of Sites
4%
3%
2%
8%
8%
13%
40%
21%
1%
(a)The DCP was mailed on January 2, 1991.
Source: MP&M Phase I DCP Database.
A majority of the sites have been built since 1960. Although the DCP respondents
report a wide range of ages, these sites must be continually modernized to remain
competitive. Most of the sites visited during the MP&M Phase I site visit program had
recently modernized some area of their site. Modernization of production processes and
air pollution control equipment produces similar wastes among all sites of various ages.
While the relative age of a site may be important in considering the economic impact of
a guideline, site age does not impact wastewater characteristics. Therefore, site age was
not selected as a basis for subcategorization.
7.9 Total Energy Requirements
Total energy requirements was not selected as a basis for subcategorization because
energy requirements are not meaningfully related to wastewater generation and pollutant
discharge. The estimated impacts of this regulation on energy consumption in the
United States is an energy increase of approximately 0.007 percent (see Section 14.0).
EPA estimated the energy requirements associated with each of the MP&M Phase I
technology options and considered these in estimating compliance costs (see
Section 12.0).
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7.0 INDUSTRY SUBCATEGORIZATION
7.10 Air Pollution Control Methods
Many sites control air emissions using wet air pollution control units that affect the
wastewater flow rate from the site. However, based on data collected during the MP&M
Phase I sampling program, wastewaters generated by these devices do not affect the
effectiveness of technologies used to control MP&M wastewaters. Wet air pollution
control units are considered as additional unit operations within the MP&M Phase I
category, but not as a means of subcategorizing the category.
7.11 Solid Waste Generation and Disposal
Physical and chemical characteristics of solid waste generated by the MP&M Phase I
category are determined by the raw materials, unit operations, and types of air pollution
control in use. Therefore, this factor does not provide a primary basis for
subcategorization. EPA considered the amount of sludge generated as a result of the
MP&M Phase I technology options, and included disposal of these sludges in the
compliance cost estimates (see Section 12.0) and nonwater quality impact assessments
(see Section 14.0).
7.12 Economic Impacts
EPA considered subcategorizing the MP&M Phase I category based on economic
characteristics of MP&M Phase I sites. EPA evaluated economic data to determine if
some groups of sites with common economic characteristics, such as revenue size, were
in a better or worse financial condition than others. However, statistical analyses of the
financial conditions of sites showed no significant pattern of variation across various
possible subcategories.
The economic characteristics of any group of sites is likely to differ from any other group
of sites. EPA used two statistical tools, linear regression and logistic regression, to
determine if these differences were random differences due to the normal variations
characteristic of all MP&M Phase I businesses, or whether these differences were
systematically and predictably related to some shared economic characteristic.
These statistical tools were used to test for systematic variations in the financial
condition and performance of sites grouped according to the following economic
characteristics:
• Primary Line of Business: Sites were assigned to MP&M Phase I
sectors according to the sector in which they earned most of their
revenues. The financial condition and performance of sites across
sectors did not vary in a statistically significant way.
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7.0 INDUSTRY SUBCATEGORIZATION
• Customer Type: Sites indicated the percentage of revenues they
earned from three customer types-government, domestic non-
government, and foreign customers. When sites were grouped
according to their dependence on each of these customer types,
statistical analyses found no significant differences in the financial
condition or performance of the various groups.
• MP&M Activity: Sites indicated the percentage of revenues they
earned from each of three categories of activities-manufacturing,
rebuilding, and maintenance. Financial condition and performance
did not vary systematically with variations in dependence on the
three activities.
• Revenue Size: Sites grouped by revenue size did not differ in
financial condition or performance in a statistically significant way.
Appendix D of the economic profile document, Industry Profile for the Metal Products
and Machinery Industry (Phase I), documents the methodology and findings in detail.
This document is located in the administrative record for this rulemaking. Based on
these analyses, EPA found no basis for subcategorizing the MP&M Phase I category
based on economic characteristics.
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Discussion Draft
Table 7-1
Metal Products and Machinery (MP&M)
Sectors and Typical Products
Sector
Typical Products
Aircraft
Aircraft
Aircraft engines and engine parts
Aircraft parts and equipment
Aerospace
Guided missiles and space vehicles
Guided missile and space vehicle propulsion
Other space vehicle and missile parts
Electronic Equipment
Telephone and telegraph apparatus
Radio and TV communications equipment
Communications equipment
Electronic tubes
Electronic capacitors
Electronic coils and transformers
Connectors for electronic applications
Electronic components
Electric lamps
Hardware
Cutlery
Hand and edge tools
Hand saws and saw blades
Screw machine products
Bolts, nuts, screws, rivets, washers
Metal shipping barrels, drums, kegs
Iron and steel forgings
Crowns and closures
Metal stampings
Steel springs
Wire springs
Miscellaneous fabricated wire products
Fasteners, buttons, needles, pins
Fluid power valves and hose fittings
Valves and pipe fittings
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Table 7-1 (Continued)
Discussion Draft
Metal Products and Machinery (MP&M)
Sectors and Typical Products
Sector
Typical Products
Hardware (Continued)
Fabricated metal pipe and fittings
Fabricated metal products
Machine tools, metal cutting types
Machine tools, metal forming types
Special dies and tools, die sets, jigs
Machine tool accessories and measuring devices
Power-driven hand tools
Heating equipment
Industrial furnaces and ovens
Fabricated structural metal
Fabricated plate work
Sheet metal work
Architectural and ornamental metal work
Prefabricated metal buildings and components
Mobile Industrial
Equipment
Farm machinery and equipment
Garden tractors and lawn and garden equipment
Construction machinery and equipment
Mining machinery and equipment
Hoists, industrial cranes and monorails
Industrial trucks, tractors and trailers
Tanks and tank components
Ordnance
Small arms ammunition
Ammunition
Small arms
Ordnance and accessories
Stationary Industrial
Equipment
Steam, gas hydraulic turbines, generators
Internal combustion engines
Oil field machinery and equipment
Elevators and moving stairways
Conveyors and conveying equipment
Industrial patterns
Rolling mill machinery and equipment
Metal working machinery
Textile machinery
Woodworking machinery
Paper industries machinery
Printing trades machinery and equipment
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Table 7-1 (Continued)
Discussion Draft
Metal Products and Machinery (MP&M)
Sectors and Typical Products
Sector
Typical Products
Stationary Industrial
Equipment (Continued)
Food products machinery
Special industry machinery
Pumps and pumping equipment
Ball and roller bearings
Air and gas compressors
Blowers and exhaust and ventilation fans
Packaging machinery
Speed changers, high-speed drivers and gears
Industrial process furnaces and ovens
Mechanical power transmission equipment
General industrial machinery
Automatic vending machines
Commercial laundry equipment
Refrigeration and air and heating equipment
Measuring and dispensing pumps
Service industry machines
Fluid power cylinders and actuators
Fluid power pumps and motors
Scales and balances, except laboratory
Industrial machinery
Welding apparatus
Transformers
Switchgear and switchboard apparatus
Motors and generators
Relays and industrial controls
Electric industrial apparatus
Heavy construction equipment rental
Source: MP&M DCPs, MP&M site visits, technical literature.
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8.0 SELECTION OF POLLUTANT PARAMETERS
8.0 SELECTION OF POLLUTANT PARAMETERS
The Agency conducted a study of MP&M wastewaters to determine the presence or
absence of priority, conventional, and nonconventional pollutant parameters. Priority
pollutant parameters are defined in Section 307(a)(l) of the Clean Water Act (CWA).
The list of priority pollutant parameters, presented in Table 8-1, consists of 126 specific
priority pollutants listed in 40 CFR Part 423, Appendix A. Section 301(b)(2) of the
CWA obligates EPA to regulate priority pollutants if they are determined to be present
at significant concentrations. Conventional pollutant parameters are defined in
Section 304(a)(4) of the CWA and include biochemical oxygen demand, total suspended
solids, oil and grease, pH, and fecal coliform. These pollutant parameters are subject to
regulation as specified in Sections 304(b)(l)(A), 304(a)(4), 301(b)(2)(E), and 306 of the
CWA. Nonconventional pollutant parameters are those that are neither priority nor
conventional pollutant parameters. Sections 301(b)(2)(F) and 301(g) of the CWA give
EPA the authority to regulate nonconventional pollutant parameters, as appropriate,
based on technical and economic considerations.
The Agency considered 330 metal and organic pollutant parameters listed in The 1986
Industrial Technology Division List of Analytes (1) for potential regulation under
MP&M Phase I. Samples collected during the MP&M sampling program were not
analyzed for two pollutant parameters initially considered by the Agency for regulation:
2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and asbestos. TCDD and asbestos are not
expected to be present in MP&M wastewaters because they have not been found to be
present in any of the raw materials used in MP&M processes, nor are they believed to
be generated by any of the processes. The Agency also considered 15 conventional and
other nonconventional pollutant parameters for potential regulation under MP&M.
These 343 pollutant parameters for which the Agency analyzed are identified in
Section 4.0.
The Agency did not consider biochemical oxygen demand (BOD5) and fecal coliform for
regulation under MP&M Phase I. These two pollutant parameters are not included in
the 343 pollutant parameters discussed above. Biochemical oxygen demand, a
measurement of the dissolved oxygen used by microorganisms to biodegrade organic
matter under aerobic conditions, is a widely used measure of general organic pollution in
wastewater. Though BOD5 is a useful gross measure of organic pollution, it does not
measure the concentrations of specific pollutant parameters. As discussed in Section 8.3,
the Agency used oil and grease as a indicator for regulation of specific organic
pollutants. The presence of fecal coliform bacteria, a microorganism that resides in the
intestinal tract of humans or other warm-blooded animals, indicates that wastewater has
been contaminated with feces from humans or other warm-blooded animals. EPA does
not expect fecal coliform to be present in wastewaters from MP&M sites.
Section 8.1 discusses the criteria used to identify pollutant parameters of concern (i.e.,
considered for regulation) under MP&M Phase I; Section 8.2 presents the results of a
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8.0 SELECTION OF POLLUTANT PARAMETERS
pass-through analysis used to select pollutant parameters considered for pretreatment
standards; and Section 8.3 discusses the criteria used to select pollutant parameters for
regulation.
8.1 Identification of Pollutant Parameters of Concern
Pollutant parameters of concern were identified using data from over 700 samples of
wastewater from MP&M unit operations and influents to treatment collected during the
MP&M sampling program described in Section 4.0. In assessing the 343 pollutant
parameters, the Agency used criteria set forth in paragraph 8(a)(iii) of the Natural
Resources Defense Council (NRDC) Consent Decree (2) for identifying pollutant
parameters of concern.
Pollutant parameters that met any of the following criteria were excluded from
consideration for regulation.
• The pollutant parameter was not detected in any sample collected
during the MP&M sampling program.
• The pollutant parameter was detected in a small number of sources.
For the MP&M program, "small" was defined as less than three
samples collected during the MP&M sampling program.
• The average concentration of the pollutant parameter in samples of
wastewater from MP&M unit operations and influents to chemical
precipitation and sedimentation treatment was less than
concentrations achievable by treatment. For the MP&M program,
"concentration achievable by treatment" was defined as 0.1 mg/L.
The average concentration was calculated assuming that
nondetected pollutants were equal to the detection limit.
• The pollutant parameter was analyzed for screening purposes and
was not analyzed for in a quantitative manner (i.e., analysis for the
pollutant parameter was not subject to quality assurance/quality
control (QA/QC) procedures).
Of the 343 pollutant parameters initially considered by the Agency for potential
regulation under MP&M, 70 were identified as pollutant parameters of concern. The
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8.0 SELECTION OF POLLUTANT PARAMETERS
other 273 pollutant parameters were not identified as pollutant parameters of concern
for the following reasons:
• One-hundred and seventy (170) pollutant parameters were not
detected in samples of wastewater from MP&M unit operations and
influents to treatment. These pollutant parameters are listed in
Table 8-2.
• Fifty-two (52) of the remaining pollutant parameters were detected
in less than three samples collected during the MP&M sampling
program. These pollutant parameters are listed in Table 8-3.
• Nine (9) of the remaining pollutant parameters were detected at
average concentrations that were less than 0.1 mg/L. These
pollutant parameters are listed in Table 8-4.
• Forty-two (42) metal pollutants were not analyzed for in a
quantitative manner. Analysis for these parameters was not subject
to the QA/QC procedures required by analytical Method 1620.
These metal pollutant analyses were used for screening purposes
and, based on the screening results, were not considered for
regulation. These pollutants are listed in Table 4-2.
The pollutant parameters identified as pollutant parameters of concern include
25 priority pollutant parameters (13 priority organic pollutants, 11 priority metal
pollutants, and cyanide), 3 conventional pollutant parameters, and 42 nonconventional
pollutant parameters (18 organic pollutants, 13 metal pollutants, and 11 other
nonconventional pollutant parameters). These pollutant parameters, along with the
number of times each pollutant parameter was analyzed and detected, and the
corresponding mean concentration (excluding nondetected pollutants), are shown in
Table 8-5.
8.2 Pass-Through Analysis for Indirect Dischargers
Section 307(b) of the CWA requires the Agency to promulgate pretreatment standards
for existing sources (PSES) and new sources (PSNS). Pretreatment standards are
established to ensure removal of pollutants which pass through publicly owned treatment
works (POTWs). The Agency evaluated POTW pass-through for the MP&M pollutant
parameters of concern, listed in Table 8-5. In determining whether a pollutant is
expected to pass through a POTW, the Agency compared the nation-wide average
percentage of a pollutant removed by well-operated POTWs performing secondary
treatment to the percentage removed by BAT treatment systems. Pollutants are
considered to pass through POTWs if the average percentage removed by BAT
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8.0 SELECTION OF POLLUTANT PARAMETERS
treatment systems is greater than the average percentage removed by well-operated
POTWs.
The Agency calculated the percentage of a pollutant removed by BAT treatment systems
using the data collected to develop long-term average technology effectiveness
concentrations for MP&M treatment systems. These data are discussed in Section 11.0.
The nation-wide average pollutant removals by well-operated POTWs performing
secondary treatment were obtained from the Fate of Priority Pollutants in Publicly
Owned Treatment Works (3), referred to as the 50-POTW Study, and the Risk
Reduction Engineering Laboratory (RREL) treatability database Release 4.0, developed
by EPA's Office of Research and Development.
Table 8-6 presents, for each MP&M pollutant parameter of concern, the BAT
percentage removal and the average POTW percent removal, and identifies which
pollutants were determined to pass through POTWs. As discussed further in
Section 10.0, the Agency believes that the primary mechanism for removal of organic
pollutants in MP&M wastewaters is oil/water separation. Therefore, the BAT
percentage removals for organic pollutants presented in Table 8-6 are based on removals
by oil/water separation units.
The Agency determined that, for 19 MP&M pollutants of concern, the BAT percentage
removal is greater than the POTW percentage amounts; therefore, these pollutants are
considered to pass through POTWs.
8.3 Pollutant Parameters Selected for Regulation
This section presents the pollutant parameters selected for limitation in the MP&M
Phase I category. These parameters were chosen from the list of 70 MP&M pollutant
parameters of concern discussed above. Although all 70 MP&M pollutant parameters of
concern were used to estimate compliance costs, pollutant loadings, and pollutant
reductions, only certain parameters were selected for limitation. The following
discussion provides EPA's rationale for the selection and exclusion of individual pollutant
parameters of concern.
The selection of pollutant parameters for regulation was based on sampling analysis data
and on information gathered in the DCPs and site visits. The sampling analysis data,
DCP data, and site visit information are all discussed in Section 4.0. In order to select
the pollutant parameters for regulation, the pollutant parameters of concern were first
grouped into seven categories: priority organic pollutants, nonconventional organic
pollutants, priority metal pollutants, nonconventional metal pollutants, cyanide,
conventional pollutant parameters, and other nonconventional pollutant parameters.
These categories and the pollutant parameters within them are presented in Table 8-5.
The selection of parameters from each of these groups is presented below.
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8.0 SELECTION OF POLLUTANT PARAMETERS
8.3.1 Priority and Nonconventional Organic Pollutants
As discussed in Section 8.1, the list of MP&M pollutant parameters of concern includes
13 priority organic pollutants and 18 nonconventional organic pollutants. A number of
different organic constituents are used in MP&M operations, but organic constituents are
infrequently detected in MP&M wastewater treatment influent streams. As shown in
Table 6-12, only ten of the 84 priority organic pollutants were detected in MP&M
wastewater treatment influent streams, and only 20 of the 149 nonconventional organic
pollutants were detected. The majority of the detected organic pollutants were detected
in fewer than three samples. The types of organic constituents used in MP&M
operations continues to expand as MP&M sites respond to the changing manufacturing
climate. For example, due to the phase-out of certain chlorinated compounds under the
Montreal Protocol and under other air pollution control requirements, many MP&M
sites are in the process of switching to alternate solvents.
Organic pollutants are used in several MP&M unit operations, as shown by the analytical
data collected at MP&M sites, data contained in the MP&M DCPs, and technical
literature. However, as discussed above, organic pollutants are infrequently detected in
MP&M Phase I wastewater treatment influent streams. The unit operations generating
organic pollutant-bearing wastewaters typically generate less wastewater than other
operations at MP&M sites. Therefore, the organic pollutants from these operations are
diluted after commingling with other MP&M process wastewaters. When organic
pollutants are detected in the wastewater treatment influent streams, they are usually
present at concentrations of less than 0.1 milligrams per liter (see Table 6-12).
EPA considered setting limitations for specific organic pollutants of concern but decided
against this approach for the following reasons: a wide variety of organic pollutants are
in use at MP&M sites; organic pollutants are typically not detected or detected at low
concentrations in raw wastewater from MP&M sites; and, MP&M sites are continuing to
switch to alternate solvents in response to the changing manufacturing climate.
EPA considered establishing limitations for Total Toxic Organics (TTO), which would
reflect the sum of concentrations achieved for several specific organic pollutants
identified during the MP&M sampling program. However, because of the diversity in
the types of cleaners, coolants, paints, and other organic pollutant-bearing solutions used
in the MP&M industry, as well as the current industry trends in identifying substitutes for
organic solvent degreasing, EPA did not have sufficient analytical data to identify and
regulate all organic pollutants in use at MP&M sites. Therefore, EPA rejected TTO as
an approach to controlling organic pollutant discharges.
After considering and rejecting the two alternatives discussed above, EPA is proposing to
use oil and grease as an indicator for monitoring for organic pollutants that have the
potential to be present in MP&M wastewaters. EPA is using oil and grease as an
indicator since most of the organic pollutants detected in MP&M wastewaters during the
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8.0 SELECTION OF POLLUTANT PARAMETERS
MP&M sampling program are more soluble in oil than in water, and as such would
partition to the oil layer. Thus, removal of oil and grease will result in significant
removal of these pollutants. Data for oil-water separation systems collected during the
MP&M sampling program show removals between 63 and 90 percent for organic
pollutants across the oil-water separation systems. These data support the conclusion
that the organic pollutants will partition to the oil layer. In addition, most of the organic
pollutants detected in MP&M wastewaters are insoluble in water, further supporting that
these pollutants will partition to the oil layer.
EPA believes that the use of oil and grease as an indicator will provide regulatory
control of organic pollutants while allowing the flexibility to control organic pollutants
used at MP&M Phase I sites but not identified during the MP&M sampling program.
8.3.2 Priority Metal Pollutants
As discussed in Section 8.1, the list of MP&M pollutant parameters of concern includes
11 priority metal pollutants. Of these metals, cadmium, chromium, copper, nickel, and
zinc were found at significant concentrations in the raw wastewater. These metals are
commonly used in the MP&M category. As a result, cadmium, chromium, copper, nickel
and zinc were selected as pollutant parameters for regulation.
The six other priority metal pollutants on the list of MP&M pollutant parameters of
concern were antimony, arsenic, lead, selenium, silver and thallium. Although these
metal pollutants were analyzed for in nearly all samples collected during the
development of the proposed MP&M Phase I rule, they were rarely detected at treatable
concentrations (i.e., 0.1 milligrams per liter) in the influent to the treatment systems
sampled. As shown in Table 6-12, the median detected concentrations for all these
pollutants except lead was less than 0.1 milligrams per liter. EPA considered
establishing limitations for lead, since lead is known to have several adverse human
health effects. However, lead was not detected in 35 of the 62 wastewater treatment
samples, and the median detected concentration in the influent to the treatment systems
was 0.251 milligrams per liter. Since these six metal pollutants were rarely found at
treatable concentrations in the raw wastewater prior to treatment, EPA did not include
them on the list of pollutant parameters for regulation.
8.3.3 Nonconventional Metal Pollutants
As discussed in Section 8.1, the list of MP&M pollutant parameters of concern includes
13 nonconventional metal pollutants. Because EPA did not have sufficient data to set
limits for all of these metal types, EPA is proposing to regulate aluminum and iron as
indicator metals for removal of non-regulated metal pollutants that may be processed at
MP&M sites. Aluminum is most effectively removed in chemical precipitation and
sedimentation systems at a pH between 7.5 and 8 standard units, while iron is most
effectively removed at a pH of approximately 10.5 standard units. Most metal pollutants
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8.0 SELECTION OF POLLUTANT PARAMETERS
that may be present in MP&M wastewaters are effectively removed in this pH range.
Therefore, removal of aluminum and iron will indicate effective removal of other metal
pollutants. Although iron and aluminum can be used as water treatment chemicals, EPA
believes that regulation of these pollutants will control discharges of non-regulated
metals that are processed at MP&M sites. Furthermore, control of aluminum and iron
to the appropriate concentrations, especially when used as treatment chemicals, would
ensure optimal operation of the wastewater treatment system.
The other 11 nonconventional metal pollutants were analyzed for in nearly all samples
collected during the development of the MP&M Phase I rule. Of these, barium, cobalt,
molybdenum, titanium, and vanadium were detected in wastewater treatment influent
streams at median concentrations less than 0.1 milligrams per liter (see Table 6-12).
EPA believes that the discharge of the other six pollutants will be adequately controlled
by regulating aluminum and iron.
Cyanide
As discussed in Section 8.1, the list of MP&M pollutant parameters of concern includes
the priority pollutant cyanide. Cyanide is commonly used in the unit operations
performed at MP&M sites. Therefore, cyanide was also selected for regulation.
Conventional Pollutant Parameters
As discussed in Section 8.1, the list of MP&M pollutant parameters of concern includes
three conventional pollutants: oil and grease, pH, and total suspended solids. EPA is
proposing to regulate all three of these conventional parameters, as discussed below.
Oil and grease can cause odor and taste problems with water and kill aquatic organisms.
Also, as discussed above, organic pollutants found in the MP&M category are more
likely to partition to the oil layer then to the water layer. Oil and grease is a significant
pollutant parameter in the MP&M category. Therefore, EPA is proposing to regulate oil
and grease as a conventional pollutant parameter in addition to regulating oil and grease
as an indicator for organics (as discussed above).
EPA is proposing a pH range limit in order to assure that the pH of the wastewater
discharged from MP&M Phase I sites is within the neutral range.
Total suspended solids (TSS) can serve to control the discharge of harmful pollutants.
TSS is a particularly important parameter when using chemical precipitation and
sedimentation systems, since the metal pollutants are removed as precipitated metal
hydroxides. Solids that remain in suspension can contain high concentrations of these
metal hydroxides. EPA is proposing to include TSS as a regulated parameter.
8-7
-------
8.0 SELECTION OF POLLUTANT PARAMETERS
Other Nonconventional Pollutant Parameters
As discussed in Section 8.1, the list of MP&M pollutant parameters of concern includes
11 other nonconventional pollutants. These parameters were analyzed for in nearly all
samples collected during the development of the MP&M Phase I rule as a qualitative
means of determining the performance of the treatment systems. EPA has used these
data to understand the performance of the treatment systems sampled, but EPA does not
propose to include any of these other nonconventionals on the list of parameters for
regulation.
8-8
-------
Table 8-1
Priority Pollutant List(a)
1 Acenaphthene
2 Acrolein
3 Acrylonitrile
4 Benzene
5 Benzidine
6 Carbon Tetrachloride (Tetrachloromethane)
7 Chlorobenzene
8 1,2,4-Trichlorobenzene
9 Hexachlorobenzene
10 1,2-Dichloroethane
11 1,1,1-Trichloroethane
12 Hexachloroethane
13 1,1-Dichloroethane
14 1,1,2-Trichloroethane
15 1,1,2,2-Tetrachloroethane
16 Chloroethane
17 Removed
18 Bis(2-chloroethyl) Ether
19 2-Chloroethyl Vinyl Ether (mixed)
20 2-Chloronaphthalene
21 2,4,6-Trichlorophenol
22 Parachlorometa Cresol (4-Chloro-3-Methylphenol)
23 Chloroform (Trichloromethane)
24 2-Chlorophenol
25 1,2-Dichlorobenzene
26 1,3-Dichlorobenzene
27 1,4-Dichlorobenzene
28 3,3'-Dichlorobenzidine
29 1,1-Dichloroethene
30 1,2-Trans-Dichloroethene
31 2,4-Dichlorophenol
32 1,2-Dichloropropane
33 1,3-Dichloropropylene (Trans-l,3-Dichloropropene)
34 2,4-Dimethylphenol
35 2,4-Dinitrotoluene
36 2,6-Dinitrotoluene
37 1,2-Diphenylhydrazine
38 Ethylbenzene
39 Fluoranthene
40 4-Chlorophenyl Phenyl Ether
41 4-Bromophenyl Phenyl Ether
42 Bis(2-Chloroisopropyl) Ether
43 Bis(2-Chloroethoxy) Methane
44 Methylene Chloride (Dichloromethane)
45 Methyl Chloride (Chloromethane)
46 Methyl Bromide (Bromomethane)
47 Bromoform (Tribromomethane)
48 Dichlorobromomethane (Bromodichloromethane)
49 Removed
50 Removed
51 Chlorodibromomethane (Dibromochloromethane)
52 Hexachlorobutadiene
53 Hexachlorocyclopentadiene
54 Isophorone
55 Naphthalene
56 Nitrobenzene
57 2-Nitrophenol
58 4-Nitrophenol
59 2,4-Dinitrophenol
60 4,6-Dinitro-o-Cresol (Phenol, 2-methyl-4,6-dinitro)
61 N-Nitrosodimethylamine
62 N-Nitrosodiphenylamine
63 N-Nitrosodi-n-propylamine (Di-n-propylnitrosamine)
64 Pentachlorophenol
65 Phenol
66 Bis(2-ethylhexyl) Phthalate
67 Butyl Benzyl Phthalate
68 Di-n-butyl Phthalate
69 Di-n-octyl Phthalate
70 Diethyl Phthalate
71 Dimethyl Phthalate
72 Benzo(a)anthracene (1,2-Benzanthracene)
73 Benzo(a)pyrene (3,4-Benzopyrene)
74 Benzo(b)fluoranthene (3,4-Benzo fluoranthene)
75 Benzo(k)fluoranthene (11,12-Benzofluoranthene)
76 Chrysene
77 Acenaphthylene
78 Anthracene
79 Benzo(ghi)perylene (1,12-Benzoperylene)
80 Fluorene
81 Phenanthrene
82 Dibenzo(a,h)anthracene (1,2,5,6-Dibenzanthracene)
83 Indeno(l,2,3-cd)pyrene (2,3-o-Phenylenepyrene)
84 Pyrene
85 Tetrachloroethylene (Tetrachloroethene)
86 Toluene
87 Trichloroethylene (Trichloroethene)
88 Vinyl Chloride (Chloroethylene)
89 Aldrin
90 Dieldrin
91 Chlordane (Technical Mixture & Metabolites)
92 4,4'-DDT (p,p'-DDT)
93 4,4'-DDE (p,p'-DDX)
94 4,4'-DDD (p,p'-TDE)
95 Alpha-endosulfan
96 Beta-endosulfan
97 Endosulfan Sulfate
98 Endrin
99 Endrin Aldehyde
100 Heptachlor
101 Heptachlor Epoxide
102 Alpha-BHC
103 Beta-BHC
104 Gamma-BHC (Lindane)
105 Delta-BHC
106 PCB-1242 (Arochlor 1242)
107 PCB-1254 (Arochlor 1254)
108 PCB-1221 (Arochlor 1221)
109 PCB-1232 (Arochlor 1232)
110 PCB-1248 (Arochlor 1248)
111 PCB-1260 (Arochlor 1260)
112 PCB-1016 (Arochlor 1016)
113 Toxaphene
114 Antimony (total)
115 Arsenic (total)
116 Asbestos (fibrous)
117 Beryllium (total)
118 Cadmium (total)
119 Chromium (total)
120 Copper (total)
121 Cyanide (total)
122 Lead (total)
123 Mercury (total)
124 Nickel (total)
125 Selenium (total)
126 Silver (total)
127 Thallium (total)
128 Zinc (total)
129 2,3,7,8-Tetrachlorodibenzo-p-Dioxin
Source: Clean Water Act
(a)Priority pollutants are numbered 1 through 129 but include 126 pollutants since EPA removed three pollutants from the list
(Numbers 17, 49, and 50).
8-9
-------
Table 8-2
Pollutant Parameters Not Detected in Samples Collected
During the MP&M Sampling Program
Priority Pollutant Parameters
3 Acrylonitrile
5 Benzidine
6 Tetrachloromethane
8 1 ,2,4-Trichlorobenzene
9 Hexachlorobenzene
12 Hexachloroethane
14 1,1,2-Trichloroethane
16 Chloroethane
18 Bis(2-chloroethyl)ether
21 2,4,6-Trichlorophenol
26 1 ,3-Dichlorobenzene
28 3,3'-Dichlorobenzidine
3 1 2,4-Dichlorophenol
32 1 ,2-Dichloropropane
3 3 trans- 1 , 3 -Dichloropropene
37 1 ,2-Diphenylhydrazine
39 Fluoranthene
40 4-Chlorophenyl Phenyl Ether
41 4-Bromophenyl Phenyl Ether
43 Bis(2-chloroethoxy)methane
45 Chloromethane
46 Bromomethane
47 Tribromomethane
51 Dibromochloromethane
52 Hexachlorobutadiene
53 Hexachlorocyclopentadiene
54 Isophorone
60 Phenol, 2-Methyl-4,6-Dinitro-
62 N-Nitrosodiphenylamine
63 Di-n-propylnitrosamine
64 Pentachlorophenol
69 Di-n-octyl Phthalate
70 Diethyl Phthalate
72 Benzo(a)anthracene
74 Benzo(b)fluoranthene
75 Benzo(k)fluoranthene
76 Chrysene
77 Acenaphthylene
83 Indeno(l,2,3-cd)pyrene
88 Vinyl Chloride
89 Aldrin
90 Dieldrin
91 Chlordane
92 4,4'-DDT
93 4,4'-DDE
94 4,4'-DDD
95 Alpha-endosulfan
96 Beta-endosulfan
97 Endosulfan Sulfate
98 Endrin
99 Endrin Aldehyde
100 Heptachlor
101 Heptachlor Epoxide
102 Alpha-BHC
103 Beta-BHC
104 Gamma-BHC
105 Delta-BHC
106 PCB-1242
107 PCB-1254
108 PCB-1221
109 PCB-1232
110 PCB-1248
111 PCB-1260
112 PCB-1016
113 Toxaphene
8-10
-------
Table 8-2 (Continued)
Pollutant Parameters Not Detected in Samples Collected
During the MP&M Sampling Program
Nonconventional Pollutant Parameters
Aniline, 2,4,5-Trimethyl-
Aramite
Benzanthrone
Benzenethiol
Benzonitrile, 3,5-Dibromo-4-Hydroxy-
Beta-Naphthylamine
Biphenyl, 4-Nitro
Carbazole
Chloroacetonitrile
Ciodrin
cis-1,3-Dichloropropene
Crotonaldehyde
Crotoxyphos
Dibenzothiophene
Dibromomethane
Dimethyl Sulfone
Diphenylamine
Diphenyl Ether
Diphenyldisulfide
Ethyl Cyanide
Ethyl Methacrylate
Ethyl Methanesulfonate
Ethylenethiourea
H exachloropropene
lodomethane
Isosafrole
Longifolene
m-Xylene
Malachite Green
Mestranol
Methapyrilene
Methyl Methacrylate
Methyl Methanesulfonate
N -N itrosodi-n-butylamine
N -Nitrosodiethylamine
N-Nitrosomethylethylarnine
N-Nitrosmethylphenylamine
N-Nitrosomorpholine
N-Nitrosopiperidine
o-Anisidine
o-Toluidine
o-Toluidine, 5-Chloro-
p-Chloroaniline
p-Dimethylaminoazobenzene
Pentachlorobenzene
Pentachloroethane
Perylene
Phenacetin
Phenothiazine
Pronamide
Pyridine
Resorcinol
Safrole
Squalene
Thianaphthene
Thioacetamide
Thioxanthe-9-one
Toluene, 2,4-Diamino-
trans-1,4-Dichloro-2-Butene
Triphenylene
Vinyl Acetate
1 -Bromo-2-Chlorobenzene
1 -Bromo-3-Chlorobenzene
l-Chloro-3-Nitrobenzene
1-Naphthylamine
1 -Phenylnaphthalene
1,1,1,2-Tetrachloroethane
1,2-Dibromo-3-Chloropropane
1,2-Dibromoethane
1,2,3-Trichlorobenzene
1,2,3-Trichloropropane
1,2,3-Trimethoxybenzene
1,2,4,5-Tetrachlorobenzene
1,3-Butadiene, 2-Chloro-
1,3-Dichloropropane
1,3-Dichloro-2-Propanol
1,3,5-Trithiane
1,4-Naphthoquinone
1,5-Naphthalenediamine
2-(Methylthio)Benzothiazole
2-Isopropylnaphthalene
2-Methylbenzothioazole
2-Phenylnaphthalene
2-Picoline
2-Propen-l-ol
2-Propenenitrile, 2-Methyl-
2,3-Benzofluorene
2,3 -Dichloroaniline
2,3 -Dichloronitrobenzene
2,3,4,6-Tetrachlorophenol
2,3,6-Trichlorophenol
2,6-Di-Tert-Butyl-p-Benzoquinone
2,6-Dichloro-4-N itroaniline
2,6-Dichlorophenol
3 -Chloropropene
3-Methylcholanthrene
3-Nitroaniline
3,3 '-Dimethoxybenzidine
3,6-Dimethylphenanthrene
4-Aminobiphenyl
4-Chloro-2-Nitroaniline
4,4'-Methylenebis(2-Chloroaniline)
4,5-Methylene Phenanthrene
5 -N itro-o-toluidine
7,12-Dimethylbenz(a)anthracene
Source: MP&M Phase I Sampling Data
8-11
-------
Table 8-3
Pollutant Parameters Detected in Less Than Three Samples
During the MP&M Sampling Program
Priority Pollutant Parameters
1 Acenaphthene
2 Acrolein (2-Propenal)
4 Benzene
7 Chlorobenzene
10 1,2-Dichloroethane
15 1,1,2,2-Tetrachloroethane
19 2-Chloroethyl Vinyl Ether
20 2-Chloronaphthalene
24 2-Chlorophenol
25 1 , 2-Dichlorobenzene
27 1 ,4-Dichlorobenzene
29 1,1-Dichloroethene
3 0 trans- 1 , 2-Dichloroethene
34 2,4-Dimethylphenol
35 2,4-Dinitrotoluene
36 2,6-Dinitrotoluene
42 Bis(2-Chloroisopropyl) Ether
56 Nitrobenzene
58 4-Nitrophenol
59 2,4-Dinitrophenol
61 N-Nitrosodimethylamine
67 Butyl Benzyl Phthalate
71 Dimethyl Phthalate
73 Benzo(a)pyrene
78 Anthracene
79 Benzo(ghi)perylene
80 Fluorene
82 Dibenzo(a,h)anthracene
84 Pyrene
87 Trichloroethene
Nonconventional Pollutant Parameters
Acetophenone
Aniline
Biphenyl
Carbon Disulfide
Dibenzofuran
Diethyl Ether
N,N-Dimethylformamide
o+p-Xylene
o-Cresol
p-Cresol
p-Cymene
p-Nitroaniline
Pentamethylbenzene
Styrene
Tripropyleneglycol methyl ether
l,2:3,4-Diepoxybutane
1 ,4-Dinitrobenzene
1,4-Dioxane
2-Hexanone
2-Nitroaniline
2,4, 5-Trichlorophenol
4-Methyl-2-pentanone
Source: MP&M Phase I Sampling Data
8-12
-------
Table 8-4
Pollutant Parameters Measured at Average Concentrations
Less Than 0.1 mg/L During the MP&M Sampling Program
Priority Pollutant Parameters
Nonconventional Pollutant Parameters
23 Chloroform
48 Bromodichloromethane
117 Beryllium
123 Mercury
Isobutyl Alcohol
Trichlorofluoromethane (formerly priority pollutant number 49)
Yttrium
1-Methylfluorene
1 -Methylphenanthrene
Source: MP&M Phase I Sampling Data
8-13
-------
Table 8-5
Pollutant Parameters Selected for Further Consideration
Under MP&M Phase I
Pollutant Parameter
Number of
Times
Analyzed
Number of
Times
Detected
Average Concentration in
Samples From Unit
Operations and Treatment
Influents (mg/L)
Priority Pollutant Parameters
11 1,1»1 -Trichloroethane
13 1,1-Dichloroefhane
22 4-Chloro-3-methylphenoI
38 Ethylbenzene
44 Methylene chloride
55 Naphthalene
57 2-Nitrophenol
65 Phenol
66 Bis(2-e(hylhexyl) phthalate
68 Di-n-butyl phthalate
81 Phenanthrene
85 Tetrachloroethene
86 Toluene
114 Antimony
115 Arsenic
118 Cadmium
1 1 9 Chromium
120 Copper
121 Cyanide
122 Lead
124 Nickel
125 Selenium (a)
126 Silver
127 Thallium
128 Zinc
55
49
39
46
87
51
40
71
45
41
41
46
48
733
745
745
745
745
190
745
733
709
723
711
722
22
8
7
5
53
14
4
37
16
3
7
9
14
299
358
514
643
698
169
425
620
234
420
213
653
9.88
0.45
171.23
8.27
497.80
3.33
4.20
14.74
13.18
1.23
1.07
54.80
0.35
7.70
0.24
156.51
1,285.76
330.83
2,355.01
62.65
385.97
0.086
0.22
0.11
134.28
(a)Selenium was detected in many of the MP&M unit operations at concentrations greater than 0.1 mg/L,
and was therefore considered for regulation.
NA - Not applicable.
8-14
-------
Table 8-5 (Continued)
Pollutant Parameters Selected for Further Consideration
Under MP&M Phase I
Pollutant Parameter
Number of
Times
Analyzed
Number of
Times
Detected
Average Concentration in
Samples From Unit
Operations and Treatment
Influents (mg/L)
Conventional Pollutant Parameters
Oil and Grease
PH
Total Suspended Solids
609
289
605
527
289
540
5,937.42
NA
957.24
Nonconventional Organic Pollutant Parameters
Alpha-terpineol
Benzoic acid
Benzyl alcohol
Hexanoic acid
N-Decane
N-Docosane
N-Dodecane
N-Eicosane
N-Hexacosane
N-Hexadecane
N-Octacosane
N-Octadecane
N -Tetracosane
N-Tetradecane
N-Triacontane
2-Butanone
2-Methylnaphthalene
2-Propanone
29
43
38
38
41
41
44
45
41
44
40
43
39
44
41
56
41
42
12
13
6
9
10
9
20
15
10
21
6
15
7
18
7
21
8
27
13.64
59.21
6.42
7.71
6.73
38.34
103.77
30.33
41.67
36.39
30.429
97.68
45.27
56.66
16.25
11.09
9.11
1.50
Nonconventional Metal Pollutant Parameters
Aluminum
Barium
Boron
723
730
745
578
596
671
249.30
4.65
54.16
(a)Selenium was detected in many of the MP&M unit operations at concentrations greater than 0.1 mg/L,
and was therefore considered for regulation.
NA - Not applicable.
8-15
-------
Table 8-5 (Continued)
Pollutant Parameters Selected for Further Consideration
Under MP&M Phase I
Pollutant Parameter
Number of
Times
Analyzed
Number of
Times
Detected
Average Concentration in
Samples From Unit
Operations and Treatment
Influents (mg/L)
Nonconventional Metal Pollutant Parameters (Continued)
Calcium
Cobalt
Iron
Magnesium
Manganese
Molybdenum
Sodium
Tin
Titanium
Vanadium
742
748
744
745
745
745
742
741
734
734
722
376
700
655
645
451
735
364
449
340
64.96
2.69
1,080.34
31.43
16.02
5.70
4,150.37
69.70
79.91
9.854
Other Nonconventional Pollutant Parameters
Acidity
Ammonia as Nitrogen
Chemical Oxygen Demand (COD)
Chloride
Fluoride
Sulfate
Total Alkalinity
Total Dissolved Solids
Total Kjeldahl Nitrogen
Total Phosphorus
Total Recoverable Phenolics
446
306
278
489
488
484
386
601
323
268
226
357
279
251
440
456
455
320
597
309
243
148
22,543.03
366.99
9,533.41
5,646.01
380.66
8,111.44
17,239.12
29,448.55
487.53
112.68
1.55
Source: MP&M Phase I Sampling Data
8-16
-------
Table 8-6
Summary of MP&M POTW Pass-Through Analysis
Pollutant Parameter(a)
BAT Percent
Removal
POTW Percent
Removal
Passes Through?
(Yes/No)
Priority Pollutant Parameters
11 1,1,1-Trichloroethane
13 1,1-Dichloroethane
22 4-Chloro-3-methylphenol
38 Ethylbenzene
44 Methylene chloride
55 Naphthalene
57 2-Nitrophenol
65 Phenol
66 Bis(2-ethylhexyl) phthalate
68 Di-n-butyl phthalate
81 Phenanthrene
85 Tetrachloroethene
86 Toluene
114 Antimony
115 Arsenic
118 Cadmium
119 Chromium
120 Copper
121 Cyanide
122 Lead
124 Nickel
125 Selenium
126 Silver
127 Thallium
128 Zinc
NA
NA
NA
NA
NA
NA
NA
23
NA
17
NA
NA
NA
NA
NA
97
99
95
>99
96
98
NA
99
NA
98
90
70
63
94
54
95
27
95
60
79
95
85
96
71
91
90
91
84
70
92
51
34
92
54
78
NA
NA
NA
NA
NA
NA
NA
No
NA
No
NA
NA
NA
NA
NA
Yes
Yes
Yes
Yes
Yes
Yes
NA
Yes
NA
Yes
NA - Not applicable. Sufficient data not available to calculate BAT percent removal and to assess pass-
through.
(a)Calcium, magnesium, and sodium are not presented in this table because these are typical wastewater
treatment chemicals at MP&M sites. Additionally, pH and total alkalinity are not presented because these
are used as performance parameters for chemical precipitation and sedimentation systems.
(b)Oil and grease is proposed for regulation as an indicator parameter for organic pollutants for
pretreatment standards.
8-17
-------
Table 8-6 (Continued)
Summary of MP&M POTW Pass-Through Analysis
Pollutant Parameter(a)
BAT Percent
Removal
POTW Percent
Removal
Passes Through?
(Yes/No)
Conventional Pollutant Parameters
Oil and Grease (b)
62
97
No
Nonconventional Organic Pollutant Parameters
Alpha-terpineol
Benzoic acid
Benzyl alcohol
Hexanoic acid
N-Decane
N-Docosane
N-Dodecane
N-Eicosane
N-Hexacosane
N-Hexadecane
N-Octacosane
N-Octadecane
N-Tetracosane
N-Tetradecane
N-Triacontane
2-Butanone
2-Methylnaphthalene
2-Propanone
NA
NA
NA
NA
NA
NA
79
NA
70
70
NA
73
NA
90
NA
NA
63
90
95
81
78
84
9
88
95
92
71
71
71
71
71
71
71
92
28
84
NA
NA
NA
NA
NA
NA
No
NA
No
No
NA
Yes
NA
Yes
NA
NA
Yes
Yes
NA - Not applicable. Sufficient data not available to calculate BAT percent removal and to assess pass-
through.
(a)Calcium, magnesium, and sodium are not presented in this table because these are typical wastewater
treatment chemicals at MP&M sites. Additionally, pH and total alkalinity are not presented because these
are used as performance parameters for chemical precipitation and sedimentation systems.
(b)Oil and grease is proposed for regulation as an indicator parameter for organic pollutants for
pretreatment standards.
8-18
-------
Table 8-6 (Continued)
Summary of MP&M POTW Pass-Through Analysis
Pollutant Parameter(a)
BAT Percent
Removal
POTW Percent
Removal
Passes Through?
(Yes/No)
Nonconventional Metal Pollutant Parameters
Aluminum
Barium
Boron
Cobalt
Iron
Manganese
Molybdenum
Tin
Titanium
Vanadium
94
NA
NA
>99
97
98
NA
NA
98
NA
17
90
70
5
83
41
52
65
69
42
Yes
NA
NA
Yes
Yes
Yes
NA
NA
Yes
NA
Other Nonconventional Pollutant Parameters
Ammonia as Nitrogen
Chemical Oxygen Demand (COD)
Chloride
Fluoride
Sulfate
Total Dissolved Solids
Total Kjeldahl Nitrogen
Total Phosphorus
Total Recoverable Phenolic s
NA
51
NA
NA
NA
NA
NA
92
NA
8
3
NA
61
NA
NA
NA
NA
NA
NA
Yes
NA
NA
NA
NA
NA
NA
NA
Source: MP&M Phase 1 Sampling Data
NA - Not applicable. Sufficient data not available to calculate BAT percent removal and to assess pass-
through.
(a)Calcium, magnesium, and sodium are not presented in this table because these are typical wastewater
treatment chemicals at MP&M sites. Additionally, pH and total alkalinity are not presented because these
are used as performance parameters for chemical precipitation and sedimentation systems.
(b)Oil and grease is proposed for regulation as an indicator parameter for organic pollutants for
pretreatment standards.
8-19
-------
8.0 SELECTION OF POLLUTANT PARAMETERS
8.4 References
1. The 1986 Industrial Technology Division List of Analytes, Revision A,
U.S. Environmental Protection Agency, Washington, D.C., April 1986.
2. Natural Resources Defense Council. Inc. vs. Train. 8 ERC 2120 (D.D.C.
1976), modified 12 ERC 1833 (D.D.C. 1979).
3. Fate of Priority Pollutants in Publicly Owned Treatment Works. EPA-
440/1-82/303, U.S. Environmental Protection Agency, Washington D.C.,
September, 1982.
8-20
-------
9.0 SOURCE REDUCTION AND RECYCLING
9.0 SOURCE REDUCTION AND RECYCLING
This section presents an overview of source reduction and recycling in the MP&M
industry. The applications and descriptions presented in this section are from the
following sources: reports prepared by EPA based on visits at MP&M sites; case studies
prepared by MP&M sites; and pollution prevention studies conducted by EPA, state and
local agencies, and MP&M sites. For a list of current EPA research projects pertaining
to source reduction and recycling technologies applicable to the MP&M industry,
contact:
Pollution Prevention Research Branch
U.S. Environmental Protection Agency
Risk Reduction Engineering Laboratory
26 W. Martin Luther King Drive (MS-466)
Cincinnati, Ohio 45268
(513) 569-7215
(513) 569-7111 (fax)
Source reduction and recycling techniques have been demonstrated at MP&M sites to
both reduce the discharge of pollutants and potentially reduce process and treatment
costs. This section has been prepared as a means of transferring information to MP&M
site personnel and local regulators concerning source reduction and recycling
opportunities available for MP&M wastes. As mentioned above, this section contains
information submitted and gathered from sources outside the Agency. EPA has not
independently confirmed the information from outside sources and makes no claims as to
the validity of the data from outside sources. References have been provided so that the
reader can gather more information directly from the sources.
The Agency recognizes that not all of the source reduction and recycling techniques
discussed in this section are applicable to all MP&M sites, and therefore may not be
applicable for development of national effluent limitations guidelines and standards.
Furthermore, specific performance requirements may preclude the implementation of
many materials substitution practices. As such, the technologies and practices discussed
in this section should be viewed as optional or voluntary practices sites can use to reduce
pollutant generation. The source reduction and recycling techniques further considered
in development of the MP&M effluent limitations guidelines and standards are discussed
in Section 10.0.
Section 9.1 describes the categories of source reduction and recycling techniques and
Section 9.2 presents examples of source reduction and recycling techniques used at
MP&M sites, including summaries of costs and benefits where available. References are
listed at the end of this section.
9-1
-------
9.0 SOURCE REDUCTION AND RECYCLING
9.1 Categories of Source Reduction and Recycling Techniques
For the purpose of this section, techniques used in the MP&M industry for source
reduction and recycling have been grouped into the following categories.
• Training and Supervision: Ensuring that employees are aware of,
understand, and support the company's source reduction and
recycling goals; translating these goals into practical information that
will enable employees to minimize waste generation through the
proper and efficient use of tools, supplies, equipment, and materials.
• Production Planning and Sequencing: Planning and sequencing
production to minimize the number of steps and eliminate
unnecessary procedures (e.g., plan production to eliminate
additional cleaning steps between other operations).
• Process or Equipment Modification: Modifying the process or
equipment to minimize the amount of waste generated (e.g.,
reducing drag-out by slowing the withdrawal speed of parts from
electroplating baths, installing electrolytic recovery units to extend
the life of electroplating baths, installing oil skimming units on
machining sumps to extend coolant life).
• Raw Material and Product Substitution or Elimination: Replacing
existing raw materials or products with other materials that produce
either less waste and/or less toxic waste (e.g., replacing chromium-
bearing solutions with nonchromium-bearing and less toxic solutions,
consolidating types of cleaning solutions and machining coolants).
• Loss Prevention and Housekeeping: Performing preventive
maintenance and managing equipment and materials to minimize
leaks, spills, evaporative losses, and other releases (e.g., installing
drip pans to capture process solution for reuse; inspecting the
integrity of tanks on a regular basis; using chemical analyses instead
of elapsed time or number of parts processed as the basis for
disposal of a solution).
9-2
-------
9.0 SOURCE REDUCTION AND RECYCLING
• Waste Segregation and Separation: Avoiding mixing different types
of wastes and avoiding mixing hazardous wastes with nonhazardous
wastes; avoiding mixing recyclable materials with noncompatible
materials or wastes (e.g., segregating scrap metal by metal type,
separating cyanide-bearing wastewaters for preliminary treatment,
separating different types of coolants for treatment and recycle).
• Closed-Loop Recycling: Separating recoverable materials in process
streams for recycling for on-site production processes (e.g., using ion
exchange to recover metal from electroplating rinse water and
recycling the deionized water, using centrifugation to recover and
reuse machining coolants).
9.2 Source Reduction and Recycling Technologies Used in the MP&M Industry
For the purpose of describing source reduction and recycling technologies, the unit
operations performed in the MP&M industry were classified into the following four
groups, as shown on Table 9-1: (1) metal shaping operations; (2) surface preparation
and treatment operations (chemical treatment and solvent cleaning); (3) metal and
organic deposition operations (including surface finishing operations); and (4) assembly
operations. This classification scheme was developed for discussing source reduction and
recycling technologies rather than for use in subcategorization or data transfer within the
MP&M industry.
Tables 9-2 through 9-6 present examples of source reduction and recycling technologies
used in the MP&M industry for the four groups of operations. Where available, these
tables identify costs, savings, and waste reduction benefits resulting from the
implementation of a specific technology. References specific to each technology are
cited in the tables under "Waste Reduction and Other Information."
9.2.1 Metal-Shaping Operations
Metal-shaping operations (including heat treatment) are performed in the MP&M
industry to alter the physical form of raw materials to make intermediate and final
products. Table 9-2 presents examples of source reduction and recycling technologies
used in the MP&M industry for metal-shaping operations.
Wastes generated from these operations are typically scrap metal, spent metal-working
fluids, and metal-bearing wastewaters. Sites commonly recycle scrap metals that have
value and defined recycling markets. Metal-working fluids are usually oil-water
emulsions or oil-based lubricants. Metal-working fluids become contaminated with
metals, tramp oils, and cleaning materials (e.g., chlorinated solvents), and spoil without
proper management and storage. The life of metal-working fluids can be increased at
the source through methods and technologies such as oil skimming, centrifugation,
9-3
-------
9.0 SOURCE REDUCTION AND RECYCLING
biocide addition, and pasteurization. Metal-bearing wastewaters typically contain metal
contaminants in a water-based slurry. These wastewaters are typically filtered and
recycled or treated to remove metals and oil and grease and then discharged.
9.2.2 Surface Preparation and Treatment Operations
Surface preparation and treatment operations (chemical treatment and solvent cleaning)
are performed in the MP&M industry to remove unwanted surface materials or to alter
the chemical or physical characteristics of a surface in preparation for subsequent
operations. Tables 9-3 and 9-4 present examples of source reduction technologies used
in the MP&M industry for chemical treatment and solvent cleaning operations,
respectively.
Wastes generated from these operations are typically metal-bearing cleaning solutions
and rinsewaters and spent solvents. Some of the cleaning solutions also contain cyanide
as a component of the solution formulation. Spent cleaning solutions and rinsewaters
are typically treated to remove metals and are then discharged.
Discharge rates of surface preparation and treatment wastewaters can be reduced at the
source through technologies such as:
• On-demand rinsing and flow control (e.g., conductivity sensors, flow
restrictors);
• Filtration and reuse of surface treatment solutions;
• Oil skimming to remove contaminants;
• Reuse of rinse waters as make-up for evaporative losses in process
baths or reuse in other rinse tanks; and
• Analytical monitoring of cleaning solutions to determine when the
solutions require discharge.
Spent solvents are typically recovered and reused either on or off site.
9.2.3 Metal and Organic Deposition Operations
Metal and organic deposition operations (including surface finishing operations) are
performed in the MP&M industry to provide either a protective or decorative coating to
a part. Table 9-5 presents examples of source reduction and recycling technologies used
by the MP&M industry for metal deposition operations.
9-4
-------
9.0 SOURCE REDUCTION AND RECYCLING
Wastewaters generated from these operations include concentrated metal-bearing
solutions, dilute metal-bearing rinse waters, and solvent-bearing and metal-bearing
wastewaters from painting and corrosion preventive coating operations. These
wastewaters are typically treated to remove metals and are then discharged.
Discharge rates of metal and organic deposition wastewaters can be reduced at the
source through technologies such as:
• On-demand rinsing and flow control (e.g., conductivity sensors, flow
restrictors);
• Reuse of rinse waters as makeup for evaporative losses from
concentrated solutions;
• Chemical recovery and reuse (e.g., ion exchange, electrowinning,
reverse osmosis, electrodialysis);
• Reuse of painting water curtains by filtration or centrifugation;
• Use of high-transfer efficiency spray painting methods; and
• Analytical monitoring of process solutions to determine when the
solutions require discharge.
9.2.4 Assembly Operations
Assembly operations are performed in the MP&M industry to provide a finish to a part
or to assemble a final product. Wastewaters generated from these operations consist of
dilute metal-bearing wastewater from mechanical finishing operations and oily wastes
from testing operations. These operations also include general maintenance operations
at MP&M sites. Table 9-6 presents examples of source reduction and recycling
technologies used in the MP&M industry for finishing operations.
9-5
-------
Table 9-1
Typical Metal Products and Machinery Operations
Metal Shaping
Abrasive Jet Machining
Electrical Discharge Machining
Electrochemical Machining
Electron Beam Machining
Grinding
Heat Treating
Metal and Organic Deposition
Anodizing
Chemical Conversion Coating
Corrosion Preventive Coating
Electroless and Immersion Plating
Electroplating
Hot Dip Coating
Impact Deformation
Machining
Plasma Arc Machining
Pressure Deformation
Thermal Cutting
Ultrasonic Machining
Mechanical Plating
Metal Spraying
Painting
Sputtering
Vacuum Metalizing
Surface Preparation and Treatment
Abrasive Blasting
Acid Treatment
Alkaline Treatment
Barrel Finishing
Chemical Machining
Electrolytic Cleaning
Assembly
Adhesive Bonding
Assembly
Brazing
Burnishing
Calibration
Disassembly
Electropolishing
Metallic Coating Stripping
Organic Coating Stripping
Salt Bath Descaling
Solvent Degreasing
Laminating
Polishing
Soldering
Testing
Thermal Infusion
Welding
ON
Source: MP&M DCPs, MP&M site visits, technical literature.
-------
Table 9-2
Examples of Source Reduction and Recycling Technologies
for Metal-Shaping Operations (a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and Other
Information [References]
Production Planning and
Sequencing
Improve scheduling of processes that require
use of varying oil types to reduce the number of
cleanouts.(b)
NA
[Reference #81](b)
Process or Equipment
Modification
Standardize the fluid types used for machining
to reduce the number of equipment cleanouts
and the amount of residual oils and mixed
wastes. This simplifies the management,
processing, and recycle of these fluids.(b)
Use specific lines for each set of processes that
require a specific fluid to reduce the number of
cleanouts.(b)
Reduce coolant costs by extending machine
coolant life through the use of a centrifuge and
the addition of biocides.(b)
NA
NA
NA
Monitor coolants (e.g., specific gravity,
conductivity, pH, biological activity, visual/odor
observations) to better control coolant
quality.(b)
Capital Investment: $5,000
Payback Period: 0.7 years(b)
[Reference #81] (b)
[Reference #81](b)
Waste Reduction: 25% in plant-wide
waste coolant generation. Based on
handling 20,600 gpy of coolant.
[Reference #81](b)
Based on handling 20,600 gpy of
coolant. [Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source references are
listed in Section 9.3 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b; the reference cited with footnote b denotes the
reference originally cited in the Bibliographic Report. Cost, saving, and waste reduction information shown on this table is based on case studies and reflects the successes reported by MP&M sites. Because
specific applications are highly variable, this information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention and
Toxics, EPA/560/8-92/001 A, January 1992.
This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-2 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal-Shaping Operations (a)
Pollution Prevention
Techniques
Process or Equipment
Modification (Continued)
Pollution Prevention Method
Use disk or belt skimmers or coalescing plate
separators to remove waste oil from machine
coolants and prolong coolant life. Also, design
sumps for ease of cleaning, (b)
Use distilled or deionized water for adjusting
coolant concentrations and maintain coolant
concentration through daily analysis. Use
disinfectant when cleaning machinery.
Use vapor-phase lubrication for metal forging
and shaping operations.
Use the same metal-working fluid throughout
the site and use a central fluid reconditioning
process to reuse the metal-working fluid.
Use a synthetic oil in metal cutting and forming
equipment to lengthen the time between oil
changes.
Install conductivity meters in chemical
machining rinses to decrease water use.
Examples of Costs and Savings
NA
NA
NA
Capital Investment: $0
Annual Savings: $4,000
Capital Investment: $2,800
Annual Savings: $800
Payback Period: 3.3 years
NA
Waste Reduction and Other
Information [References]
Coolant disposal reduced from 3 to 6
times per year to once per year.
[Reference #6](b)
[Reference #89]
Waste Reduction: 85% lubricant
volume reduction. [Reference #92]
Waste Reduction: 24,000 gpy of
waste metal working fluid.
[Reference #153].
Waste Reduction: 700 gpy of waste
oil. [Reference #171].
[Site 17309](c)
oo
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source references are
listed in Section 9.3 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b; the reference cited with footnote b denotes the
reference originally cited in the Bibliographic Report. Cost, saving, and waste reduction information shown on this table is based on case studies and reflects the successes reported by MP&M sites. Because
specific applications are highly variable, this information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention and
Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-2 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal-Shaping Operations(a)
Pollution Prevention
Techniques
Process or Equipment
Modification (Continued)
Raw Material Substitution
Waste Segregation and
Separation
Pollution Prevention Method
Replace thermal treatment of metals with
condensation of saturated chlorite vapors on the
surface to be heated. This process eliminates
the need for subsequent pickling.(b)
In cold forming or other processes where oil is
used only as a lubricant, substitute a hot lime
bath or borax soap for oil.(b)
Use a stamping lubricant that remains on the
piece until the annealing process, where it is
burned off. This eliminates the need for
hazardous degreasing solvents and alkali
cleaners.(b)
Substitute synthetic coolant for sulphurized oil
used in honing process and eliminate hot water
wash following honing operation.
Segregate metal scrap by type to facilitate resale
of the metal (e.g., sell previously disposed
metallic dust to a smelt er).(b)
Examples of Costs and Savings
NA
NA
Capital Investment: Less than $30,000
Annual Savings: $12,000 (results from
reduced disposal, raw
material, and labor
costs) (b)
Reduced raw material costs by 67%.
Capital Investment: $0
Annual Savings: $130,000
Payback Period: Immediate(b)
Waste Reduction and Other
Information [References]
[Reference #81](b)
[Reference #81] (b)
Waste Reduction: The amount of
waste solvents and cleaners was
reduced from 30,000 Ibs in 1982 to
13,000 Ibs in 1986. Employee
working conditions were also
improved by removing vapors
associated with solvent cleaners.
[Reference #7](b)
Waste Reduction: 128 gpy of waste
oil. [Reference #88]
Waste Reduction: 2,700 tons of
scrap metal per year. [Reference
#19](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source references are
listed in Section 9.3 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b; the reference cited with footnote b denotes the
reference originally cited in the Bibliographic Report. Cost, saving, and waste reduction information shown on this table is based on case studies and reflects the successes reported by MP&M sites. Because
specific applications are highly variable, this information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention and
Toxics, EPA/560/8-92/001 A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-2 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal-Shaping Operations (a)
Pollution Prevention
Techniques
Waste Segregation and
Separation (Continued)
Recycling
Pollution Prevention Method
Improve housekeeping techniques and segregate
waste streams (e.g., segregate used oils, when
cleaning cutting equipment prevent mixing
cutting oil and cleaning solvent). (b)
Recycle metal-working fluids from cutting and
machining operations. Oils may not need
treatment before recycling.(b)
Install a second high-speed centrifuge on a
system already operating with a single
centrifuge to improve recovery efficiency.(b)
Install a coolant recovery system and collection
vehicle for machines not on a central coolant
sump.(b)
Use a settling tank (to remove solids) and a
coalescing unit (to remove tramp oils) to
recover metal- working fluids, (b)
Use a coalescing plate separator to recycle
machining coolant.
Examples of Costs and Savings
Capital Investment: $0
Annual Savings: $3,000 (in disposal
costs) (b)
Capital Investment: $1,900,000
Annual Savings: $156,000(b)
Capital Investment: $126,000
Payback Period: 3.1 years(b)
Capital Investment: $104,000
Payback Period: 1.9 years(b)
Capital Investment: Less than $30,000
Annual Savings: $26,800 (resulting
from reduced
material, labor, and
disposal costs) (b)
67% reduction in coolant costs
Waste Reduction and Other
Information [References]
Waste Reduction: 30 tons reduced
to 10 tons. [Reference #81](b)
Based on recycling 2 million gpy of
oil. [Reference #19](b)
Based on handling 20,600 gpy of
coolant. [Reference #81](b)
Based on handling 20,600 gpy of
coolant. [Reference #81](b)
Includes settling tank to remove
solids. [Reference #20](b)
Waste Reduction: 52,500 gpy of
waste oil. [Reference #90]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source references are
listed in Section 9.3 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b; the reference cited with footnote b denotes the
reference originally cited in the Bibliographic Report. Cost, saving, and waste reduction information shown on this table is based on case studies and reflects the successes reported by MP&M sites. Because
specific applications are highly variable, this information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention and
Toxics, EPA/560/8-92/001 A, January 1992.
-------
Table 9-2 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal-Shaping Operations (a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Install an oil condensing system to reclaim
evaporating oil.
Install collection/drip pans under machinery
and lubrication operations to recover oils.(b)
Centrifuge oil and scrap metal mixtures or
install a chip wringer to recover excess coolant
for reuse. (b)
Use a centrifuge to recycle metal-working fluids
from machining chips.
Install ultrafiltration to recycle metal-working
fluids.
Examples of Costs and Savings
Capital Investment: $7,400
Annual Savings: $56,250
Payback Period: 0.1 years
NA
Capital Investment: $233,500
Payback Period: 0.9 years(b)
Capital Investment: $11,000 to $23,000
(chip wringer and
centrifuge system) (b)
Capital Investment: $23,525
Annual Savings: $21,291
Payback Period: 1.1 years
Capital Investment: $42,000
Annual Savings: $33,800(b)
Annual Savings: $200,000 (in disposal
costs) (b)
Waste Reduction and Other
Information [References]
Waste Reduction: 18,750 gpy of oil.
[Reference #84]
[Reference #81](b)
Based on handling 20,600 gpy of
coolant. [Reference #81](b)
[Reference #81] (b)
[Reference #9]
[Reference #81](b)
Based on a wastewater flow rate of
860 to 1,800 gpd. [Reference
#81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source references are
listed in Section 9.3 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b; the reference cited with footnote b denotes the
reference originally cited in the Bibliographic Report. Cost, saving, and waste reduction information shown on this table is based on case studies and reflects the successes reported by MP&M sites. Because
specific applications are highly variable, this information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention and
Toxics, EPA/560/8-92/001 A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-2 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal-Shaping Operations (a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Perform on-site purification of hydraulic oils
using cartridge filter system, (b)
Recycle metal-working fluids on site by filtering,
and treat spent fluids with acid to reduce
volume of waste to be shipped off site.
Filter and recycle aqueous cutting fluids.
Use a portable sump to remove cutting fluid
from chip collection bins for filtration and
recycle.
Examples of Costs and Savings
Capital Investment: $28,000
Annual Savings: $17,800 (based on
operating costs,
reduced oil purchase,
and lost resale
revenues)
Payback Period: Less than 2 years(b)
Capital Investment: $7,050
Annual Savings: $3,120
Payback Period: 2.3 years
Capital Investment: $11,750
Annual Savings: $6,140
Payback Period: 1.9 years
Capital Investment: $22,400
Annual Savings: $17,430
Payback Period: 1.3 years
Capital Investment: $0
Annual Savings: $3,120
Waste Reduction and Other
Information [References]
Based on 12,300 gpy of waste
hydraulic oil. [Reference #81](b)
Waste Reduction: 425 gpy of cutting
fluid. [Reference #83]
Waste Reduction: 2,075 gpy of
cutting fluid. [Reference #87]
Waste Reduction: 31,340 gpy of oil.
[Reference #86]
Waste Reduction: 16,480 gpy of
fluid. [Reference #86]
K)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source references are
listed in Section 9.3 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b; the reference cited with footnote b denotes the
reference originally cited in the Bibliographic Report. Cost, saving, and waste reduction information shown on this table is based on case studies and reflects the successes reported by MP&M sites. Because
specific applications are highly variable, this information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention and
Toxics, EPA/560/8-92/001 A, January 1992.
-------
Table 9-2 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal-Shaping Operations (a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Add magnesium chloride as a de-emulsifying
agent to break oil-water emulsion and recycle
oil layer.
Recycle spent blasting abrasives by mixing them
into asphaltic concrete.
Install a coolant recycling system and reuse
coolant in grinding and machining operations.
Recycle water used in abrasive jet machining
operation using electrolytic recovery, filtration,
and ion exchange.
Sell metal fines from abrasive blasting and
machining operations for reclamation. Reuse
hydraulic oil in machining operations.
Recycle oil quench baths on site by filtering out
the metals. (b)
Examples of Costs and Savings
Capital Investment: $2,500
Annual Savings: $6,820
Payback Period: 0.4 years
Savings: $450 per ton of waste
NA
NA
NA
NA
Waste Reduction and Other
Information [References]
Waste Reduction: 16,230 gpy of oil.
[Reference #85]
[Reference #190].
[Sites 3036, 4133, 5911, 6054, 6233,
9081, 10843, 11286, 11579, 15000,
15632, 15908, 16905, 17309, 17325,
19698, 20813, 20914, 22208, and
24251] (c)
[Site 11286](c)
[Sites 914, 1220, 4208, 6233, 6924,
7175, 9456, 10283, 11286, 11579,
13103, 14043, 15000, 16589, 18802,
19225, and 23653](c)
[Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source references are
listed in Section 9.3 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b; the reference cited with footnote b denotes the
reference originally cited in the Bibliographic Report. Cost, saving, and waste reduction information shown on this table is based on case studies and reflects the successes reported by MP&M sites. Because
specific applications are highly variable, this information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention and
Toxics, EPA/560/8-92/001 A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-3
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Surface Treatment (a)
Pollution Prevention
Techniques
Production Planning and
Sequencing
Process or Equipment
Modification
Pollution Prevention Method
Discharge acid and alkaline treatment
baths based on the results of chemical
analysis rather than schedule.
Use countercurrent rinses after each
process to reduce wastewater
discharge.(b)
Increase rinsing efficiency by using air
spargers. Reduce wastewater discharge
by installing flow control meters.
Reduce rinse contamination via drag-out
by slowing removal of parts from process
baths, rotating the parts if necessary, (b)
Reduce rinse contamination via drag-out
by using drainage boards that direct
dripping solutions back to process
tanks.(b)
Reduce rinse contamination via drag-out
by installing drag-out recovery tanks. (b)
Examples of Costs and Savings
NA
Capital Investment: $800
Annual Savings: $4,630
Payback Period: 0.2 year(b)
Annual Savings: $1,800 in water and sewer
fees, plus reduced treatment
chemical and waste handling
costs.
NA
NA
NA
Waste Reduction and
Other Information [References]
[Sites 3960 and 7972] (c)
Waste Reduction: 2,171,520 gpy.
[Reference #94](b)
50% reduction in water usage.
[Reference #103]
[Reference #81](b)
[Reference #81](b) [Site
3960](c)
[Reference #81](b)
NA Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics. EPA/560/8-92/001A, January 1992.
-------
Table 9-3 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Surface Treatment (a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Process or Equipment
Modification (Continued)
v
Reduce rinse contamination via drag-out
by using a fog spray rinsing technique
above process tanks.(b)
Reduce rinse contamination via drag-out
by using techniques such as air knives or
squeegees to wipe bath solutions off of
the part.(b)
Reduce rinse contamination via drag-out
by changing bath temperature or
concentration to reduce the solution
surface tension.(b)
Decant organic coating stripping solution
and remove sludge from bath.
NA
NA
NA
NA
Use barrel finishing with glass marbles or
steel balls instead of pickling in nitric
acid. Use an acidic additive with the
glass marbles and a slightly basic additive
with the steel balls.(b)
Capital Investment: $62,300(b)
[Reference #81](b)
[Reference #81](b)
[Sites 2306 and 17479](c)
[Reference #81](b)
Reduce bath discharge from once
per month to once per year.
[Site 5410](c)
[Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-3 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Surface Treatment(a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Process or Equipment
Modification (Continued)
Use mechanical scraping instead of acid
solution to remove oxides of titanium, (b)
Investment:
Annual Savings:
Less than $30,000
$0
Cost of mechanical stripping
equals cost of chemical
disposal.(b)
Waste Reduction: 100%.
Previously disposed 15 tons of
acid per year with metals.
[Reference #81](b)
Replace alkaline etching of nickel and
titanium with a mechanical abrasive
system.(b)
Capital Investment: $3,250
Annual Savings: $7,500(b)
Waste Reduction: 100%.
Previously disposed of 12,000 gpy
of etching solution.
[Reference #81](b)
Clean copper sheeting mechanically with
a rotating brush machine that scrubs with
pumice, instead of cleaning with
ammonium persulfate, phosphoric acid,
or sulfuric acid (may generate
nonhazardous waste sludge).(b)
Capital Investment: $59,000
Annual Savings: $15,000 (in raw materials,
disposal, and labor)
Payback Period: 4 years(b)
Waste Reduction: 40,000 Ib/yr of
hazardous copper etching waste
liquid. [Reference #81](b)
Install an acid cleaning bath maintenance
system including oil skimming and
cartridge filtration.
Capital Investment: $12,220
Annual Savings: $44,190
Payback period: 0.3 years
Expected to extend bath life by
one year. [Reference #162]
Use a mechanical de-scaling system
rather than acid treatment to remove
scale from wire rod.
NA
Waste Reduction: 355,000 Ibs
per year of sulfuric acid.
[Reference #180].
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-3 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Surface Treatment(a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Process or Equipment
Modification (Continued)
Use conductivity meters to reduce the
quantity of wastewater discharged from
NA
rinses.
Use on-demand rinsing (i.e., shut off
water discharge when rinse is not in use)
to reduce the quantity of wastewater
discharged from rinses.
NA
Use flow restrictors to reduce the
quantity of wastewater discharged from
rinses.
NA
[Sites 3960, 6028, 6233, 7159,
10674, 10843, 13103, 16385, 17309,
19102, 21293, and 24251](c)
[Sites 2100, 2306, 2948, 3793,
3960, 5410, 6306, 6233, 7159,
10674, 11507, 17309, 17325, 17479,
19225, 19698, 20532, 20813, 22734,
and 23653] (c)
[Sites 3862, 5410, 6233, 10283,
10565, 17325, 19225, 19698, 20532,
and 20813](c)
Raw Material Substitution
Change copper bright-dipping process
from a cyanide dip to a sulfuric
acid/hydrogen peroxide dip. The new
bath is less toxic, (b)
NA
Use alcohol instead of sulfuric acid to
pickle copper wire. One ton of wire
requires 4 liters of alcohol solution,
versus 2 kilograms of sulfuric acid.(b)
Capital Investment: $0(b)
[Reference #81](b)
[Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-3 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Surface Treatment(a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Raw Material Substitution
(Continued)
OO
Replace caustic wire cleaner with a
biodegradable detergent.(b)
NA
Replace chromated etching solutions with
nonchromated alkaline solutions for
etching of wrought aluminum, (b)
Annual Savings: $44,541(b)
Replace barium and cyanide salt heat
treating with a carbonate and chloride
carbon mixture, or with furnace heat
treating.(b)
NA
Substitute chromic acid cleaner with
cleaners such as sulfuric acid and
hydrogen peroxide.(b)
[Reference #81](b)
Waste Reduction: 50% reduction
in sludge disposal costs.
[Reference #81](b)
[Reference #81] (b)
Capital Investment: Less than $30,000
Cost Savings: $10,000 in treatment
equipment costs and $2.50/lb
of chromium in treatment
chemical costs, (b)
Based on rinse water flow rate of
2 gpm. [Reference #81](b)
Substitute nonhazardous cleaners such as
trisodium phosphate or ammonia for
cyanide cleaners.(b)
Capital Investment: Less than $30,000
Cost Savings: $12,000 in equipment costs
and $3.00/lb of cyanide in
treatment chemical costs.(b)
Based on rinsewater flow rate of
2 gpm. [Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-3 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Surface Treatment(a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Recycling
Replace cyanide-bearing nickel stripping
process with a non-cyanide bearing nickel
stripping process.
NA
Sell waste pickling acids as feedstock for
fertilizer manufacturer or neutralization
and precipitation.(b)
NA
Recover metals from solutions using ion
exchange and electrolytic recovery.(b)
Annual Savings: $22,000(b)
Send used copper pickling baths to a
continuous electrolysis process for
regeneration and copper recovery.(b)
Capital Investment: $28,500(b)
Recover copper from brass bright dipping
solutions using ion-exchange system. (b)
Investment:
Annual Savings:
[Reference #184]
[Reference #81](b)
Company sells copper recovered
from a bright-dip bath
regeneration process. [Reference
#19](b)
200 gallons of solution are
recovered per ton of copper
processed. [Reference #81](b)
Less than $30,000(b)
$17,047; based on labor
savings, copper sulfate
elimination, sludge reduction,
copper metal savings, and
bright dip chemicals
savings.(b)
Facility processes approximately
225,000 Ib/month brass.
[Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics. EPA/560/8-92/001A. January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-3 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Surface Treatment(a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Filter and reuse acid treatment baths.
Extend alkali wash life by skimming the
oil layer and reclaiming the skimmed
oil.(b)
Recover acids from pickling baths using
diffusion dialysis.
Use ultrafiltration to recycle spent iron
phosphating/degreasing baths.
Use an in-process treatment system to
regenerate and reuse solutions for
chemical milling of aluminum.(b)
Examples of Costs and Savings
NA
NA
NA
Capital Investment: $2,200,000
Annual Savings: $603,000
Payback Period: 3.6 years
Capital Investment: $12,000
Capital Investment: $465,000
Annual Savings: $342,000
Payback Period: Less than 2 years(b)
Waste Reduction and
Other Information [References]
Extended bath life by 70%.
[Site 6924]
[Reference #81](b)
Waste Reduction: 6,000 m3/yr of
sludge and 3,200 m3/yr of acids.
[Reference #96]
[Reference #99]
Waste reduction: 15,000 gpy
(99.8%) of spent solution.
[Reference #116]
Waste Reduction: 90%.
[Reference #81] (b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) 'This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-3 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Surface Treatment(a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Recycling (Continued)
Regenerate alkaline etching solution for
aluminum by using hydrolysis of sodium
aluminate to liberate free sodium
hydroxide and produce a dry, crystalline
hydrate alumina byproduct.(b)
Capital Investment: $260,000
Annual Savings: $169,282 (from reduced
alkaline solution use, income
from the sale of the
byproduct, and a reduction in
the cost of solid waste
disposal)
Payback Period: 1.5 years(b)
Based on an anodizing operation
for which the surface area is
processed at a rate of 200 m2/hr.
[Reference #81](b)
Purify and reuse alkaline cleaning
wastewater from an automotive parts
washer using emulsion breaking,
skimming, and cartridge filtration. Reuse
75% of the washwater; add fresh solution
as necessary.
Capital Investment: $19,800
Annual Savings: $107,100
Payback Period: 0.18 years
Use waste acid detoxification and
reclamation (WADR) process (metal
precipitation and vacuum distillation) to
purify spent acid from acid treatment
baths for reuse.
NA
Approximately 29,000 gpy of
RCRA characteristic hazardous
wastes D007 and D008 were
generated at the facility from the
parts washer prior to installing
the treatment system. [Reference
#159]
[Reference #172]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g.. [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-3 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations • Surface Treatment(a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Use in-process precipitation or vacuum
distillation to recycle spent acids.
Regenerate ferricyanide etchants by
bubbling ozone through spent etchants.
Use acid treatment and alkaline
treatment operation discharges for
treatment chemicals.
Use rinse water as make-up for process
chemicals
Use ultrafiltration or nanofiltration to
recycle barrel finishing wastewater.
Use ground corn cob dry burnishing
process to replace wet tumbling.
Examples of Costs and Savings
NA
Capital Investment: $100,000
Annual Savings: $250,000
NA
NA
Capital Investment: $5,500
Annual Operating
Costs: $2,500
Annual Savings: $6,657
Annual Savings: $17,850
Waste Reduction and
Other Information [References]
Waste Reduction: 85% recovery
of copper, 80% recovery of nitric
acid, and 40% reduction in waste
volumes. [Reference #100]
Improved etchant performance
has increased process throughput
by 50%. [Reference #179]
[Sites 6306, 6924, 7159, 10843,
16589, 17325, 17479, 19698, 22734,
and 24251] (c)
[Sites 6054, 6233, 13682, 18802,
and 19019] (c)
[Reference #152]
[Reference #152]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-4
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Solvent Cleaning(a)
Pollution Prevention
Techniques
Training and Supervision
Production Planning and
Sequencing
Pollution Prevention Method
Improve solvent management by requiring
employees to obtain solvent through their
shop foreman.(b)
Use software packages to assist with
decisions concerning solvent replacements.
Preclean parts to extend the life of the
aqueous or vapor degreasing solvent.(b)
Reuse "waste" solvents from cleaner
upstream operations in downstream,
machine shop-type processes. (b)
Use countercurrent solvent cleaning (i.e.,
clean initially in previously used solvent and
progress to new, clean solvent). (b)
Cold clean with a recycled mineral spirits
stream to remove the bulk of oil before
final vapor degreasing. (b)
Examples of Costs and Savings
NA
NA
Annual Savings: $40,000
Payback Period: 2 years(b)
Capital Investment: $0
Annual Savings: $7,200(b)
NA
NA
Waste Reduction and
Other Information [References]
[Reference #23](b)
[Reference #112]
Waste Reduction: 48,000 gal of
aqueous waste. Aluminum shot
was used to preclean parts.
[Reference #19](b)
Waste Reduction: 51% (310 tons
reduced to 152 tons). [Reference
#23](b)
[Reference #81](b)
[Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A. January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-4 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Solvent Cleaning (a)
Pollution Prevention
Techniques
Process or Equipment
Modification
Pollution Prevention Method
Cover the solvent degreasing unit.
Increase the freeboard height above the
vapor level to 100% of tank width.
Install refrigerator coils (or additional coils)
above the degreaser vapor zone.(b)
Add in-line filters to prevent particulate
buildup in the degreaser. (b)
Reduce grease accumulation by adding
automatic oilers to avoid excess oil
applications.(b)
Use plastic blast media for paint stripping
rather than conventional solvent stripping
techniques, (b)
Examples of Costs and Savings
Capital Investment: $220
Annual Savings: $17,180
Payback Period: 0.01 years
Capital Investment: $1,250
Annual Savings: $4,118
Payback Period: 0.3 years
Operating costs can be reduced by 30 to
50%.
NA
NA
Investment: Less than $30,000 (b)
NA
Waste Reduction and
Other Information [References]
Waste Reduction: 50%
[Reference #93]
Waste Reduction: 9,900 Ibs per
year of solvent. [Reference
#170]
[Reference #102]
[Reference #81](b)
[Reference #81](b)
[Reference #81](b)
Waste Reduction: volume of
waste sludge is reduced by as
much as 99% over chemical
solvents; wastewater fees are
eliminated. [Reference #81](b)
NA Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-4 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Solvent Cleaning(a)
Pollution Prevention
Techniques
Process or Equipment
Modification (Continued)
Pollution Prevention Method
Use a vacuum furnace to vaporize oil from
parts, replacing solvent degreasing.
Use hermetically sealed vapor degreasing
units.
Use carbon dioxide (CO2) blasting as an
alternative to solvent stripping or
degreasing.
Use carbon dioxide (CO2) blasting as an
alternative to solvent stripping or
degreasing.
Use an abrasive deburring system to clean
metal parts instead of solvents.
Examples of Costs and Savings
Capital Investment: $192,000
NA
Savings: for paint stripping from aircraft,
cost for CO2 blasting is $0.51/ft2 compared
to $1.50 to $2.25/ft2 for stripping using
plastic blast media or solvents.
Cost of stripping reduced from $19/ft2 to
$5/ft2.
Capital Investment: $9,000
Annual Savings: $36,000
Payback Period: 0.25 years
NA
Waste Reduction and
Other Information [References]
Parts must be able to withstand
temperatures between 210-650° F.
[Reference #95]
Waste Reduction: Reduces use
of 1,1,1-trichloroethane (TCA) by
40,000 Ibs/yr. [Reference #97]
[Reference #6]
Waste Reduction: 96% reduction
in chemical stripping wastes.
[Reference #109]
Waste Reduction: 1,100 gpy of
TCA. [Reference #107]
[Sites 914, 7175, 13103, and
15908](c)
K)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics. nPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-4 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Solvent Cleaning(a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Process or Equipment
Modification (Continued)
VO
Use bicarbonate of soda stripping process
for paint stripping as an alternative to
solvent stripping.
NA
Use high-pressure supercritical carbon
dioxide process as an alternative to solvent
degreasing for removing machining coolant
from parts.
NA
Use machining coolants and lubricants that
do not require solvent degreasing after
machining.
NA
Reduce the surface area of a methyl ethyl
ketone (MEK) tank used for an organic
coating stripping operation to reduce loss of
MEK to atmosphere.
Capital Investment: $3,000
Annual Savings: $11,240
Payback Period: 0.3 years
[Reference #110]
[Reference #111]
[Reference #115]
Waste Reduction: 37.6% less
MEK used each year. [Reference
#164]
Raw Material Substitution
Use less hazardous degreasing agents such
as petroleum solvents or alkali washes. For
example, replace halogenated solvents (e.g.,
trichloroethylene) with aqueous cleaner.
(Note that compatibility of aqueous cleaners
with wastewater treatment systems should
be considered.)
Capital Investment: $0
Annual Savings: $12,000(b)
Waste Reduction: 30% of
1,1,1-trichloroethane replaced
with an aqueous cleaner.
[Reference #7](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
anH Tr*vi^e KPA /Z /nm A T—. 100^
-------
Table 9-4 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Solvent Cleaning(a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Raw Material Substitution
(Continued)
Use less hazardous degreasing agents such
as petroleum solvents or alkali washes. For
example, replace halogenated solvents (e.g.,
trichloroethylene) with liquid alkali cleaning
compounds. (Note that compatibility of
aqueous cleaners with wastewater treatment
systems should be considered.) (Continued)
N)
Capital Investment: $438,000
Payback Period: 5.1 years(b)
NA
Annual Savings:
Payback Period:
$2,000
1.6 years(b)
Replaced trichloroethylene
degreaser with aqueous cleaner
system. [Reference #26](b)
[Sites 3862, 4208, 4979, 7159,
9081, 11316, 13103, 14881, 15908,
16589, 17309, 17479, 18802, 19225,
and 20813](c)
Substituted chlorofluorocarbon
solvents with proprietary cleaner.
[Reference #81](b)
Annual Savings:
Payback Period:
38% of cost savings
and a 62% return on
investment.
1.6 years(b)
Substituted chlorofluorocarbon
solvents with proprietary cleaner.
[Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-4 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Solvent Cleaning(a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Raw Material Substitution
(Continued)
Use less hazardous degreasing agents such
as petroleum solvents or alkali washes. For
example, replace halogenated solvents (e.g.,
trichloroethylene) with liquid alkali cleaning
compounds. (Note that compatibility of
aqueous cleaners with wastewater treatment
systems should be considered.) (Continued)
N>
oo
NA
Waste Reduction: 32 tpy of
flammable ethyl alcohol.
Replaced methanol with
nonflammable aqueous cleaners.
[Reference #101]
Total savings of $106,395 in material, direct
costs, and indirect labor and maintenance
costs. Resulted in 117% pre-tax rate of
return.
Capital Investment: $5,000
Annual Savings: $67,200
Capital Investment: $50,000
Annual Savings: $20,450
Payback Period: 2.4 years
Capital Investment: $18,000
Annual Savings: $96,000
Replaced methylene chloride
degreaser with an aqueous
cleaning system. [Reference
#105]
Waste Reduction: 24,000 Ib/yr of
CFC-113. Replaced with spray
alkaline cleaner. [Reference
#108]
Waste Reduction: 99% using
ultrasonic cleaning with
biodegradable detergents.
[Reference #93]
Waste Reduction: 1,000 gallons
per month of TCA and freon 113
using ultrasonic cleaning.
[Reference #95]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g.. [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-4 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Solvent Cleaning(a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Raw Material Substitution
(Continued)
Use less hazardous degreasing agents such
as petroleum solvents or alkali washes. For
example, replace halogenated solvents (e.g.,
trichloroethylene) with liquid alkali cleaning
compounds. (Note that compatibility of
aqueous cleaners with wastewater treatment
systems should be considered.) (Continued)
Capital Investment: $1,793
Annual Savings: $4,800
Payback Period: 0.38 years
Capital Investment: $3,520
Annual Savings: $1,340
Payback Period: 2.6 years
Capital Investment: $159,600
Annual Savings: $56,800
Payback Period: 2.8 years
NA
Replaced TCA and methanol
degreasing with terpene-based
aqueous degreasing. [Reference
#113]
Waste Reduction: 15,600 gpy of
spent TCA. [Reference #168]
Replaced CFC cleaning process
with an aqueous cleaning process.
[Reference #175]
Ultrasonic cleaning with aqueous
detergents replaced solvent
degreasing with 1,1,2-trichloro-
trifluoroethane, methylchloro-
form, and perchloroethylene.
[Reference #173]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics. EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-4 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Solvent Cleaning(a)
Pollution Prevention
Techniques
Raw Material Substitution
(Continued)
Loss Prevention and
Housekeeping
Loss Prevention and
Housekeeping (Continued)
Pollution Prevention Method
Replace vapor degreasing units with an
aqueous washer. Treat aqueous solution
with mechanical filtration and oil skimming.
Improve performance of the solvent capture
system for a vapor degreasing unit.
Only degrease parts that must be cleaned.
Do not routinely degrease all parts. (b)
Rotate parts before removal from the vapor
degreaser to allow all condensed solvent to
return to degreasing unit.(b)
Control the speed at which parts are
removed from the degreaser to reduce
disruption of the vapor line.(b)
Examples of Costs and Savings
NA
Capital Investment: $500
Annual Savings: $400
Payback Period: 1.2 years
NA
NA
NA
Waste Reduction and
Other Information [References]
The aqueous washer cleans most
parts well enough to by-pass a
wet tumbling process, reducing
the amount of wastewater
discharged from tumbling by
50%. [Reference #174]
Waste Reduction: 30% reduction
in trichloroethylene loss per year.
[Reference #155]
[Reference #81](b)
[Reference #81](b)
[Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A. Januarv 1992
-------
Table 9-4 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Solvent Cleaning(a)
Pollution Prevention
Techniques
Recycling
Pollution Prevention Method
Recycle spent degreasing solvents on site
using batch stills.
Examples of Costs and Savings
Capital Investment: $7,500
Annual Savings: $90,000
Payback Period: 0.08 years(b)
Capital Investment: $2,600-$4,100 and
$4,200-$17,000.(b)
Capital Investment: $55,000
Annual Savings: $200,000
Payback Period: Less than 0.33 years
NA
Capital Investment: $3,500
Annual Savings: $50,400(b)
Capital Investment: $5,000
Annual Savings: $4,240
Payback Period: 1.2 years
Waste Reduction and
Other Information [References]
Waste Reduction: 10,000 gph of
spent solvent by in-house
distillation. [Reference #19](b)
Based on 35-60 gph and 0.6-
20 gph, respectively. Cost and
throughput estimates for
distillation units from two
vendors. [Reference #81] (b)
Waste Reduction: 90% of spent
solvent recovered. [Reference
#114]
[Site 24521]
Facility handles 40,450 gpy of
TCA. [Reference #81](b)
Waste Reduction: 80% reduction
in waste TCA per year.
[Reference #155]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics. EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-4 (Continued)
Examples of Source Reduction and Recycling Technologies
for Surface Preparation Operations - Solvent Cleaning(a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Use ozonation-membrane process to
recover solvents.
Arrange a cooperative agreement with other
small companies to centrally recycle
solvent.(b)
Examples of Costs and Savings
NA
Investment: Less than $30,000(b)
Waste Reduction and
Other Information [References]
Waste Reduction: 99.8%
reduction of trichlorophenol.
[Reference #104]
[Reference #81](b)
SO
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g.. [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics. EPA/560/8-92/001A, January 1992,
-------
Table 9-5
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Training and Supervision
Production Planning and
Sequencing
Pollution Prevention Method
Train plating shop personnel in water
conservation and source reduction
practices, (b)
Improve paint quality and work
efficiency and lower vapor emissions by
formally training operators.(b)
Pre-inspect parts to prevent processing
of obvious rejects.(b)
Use the correct spray gun for
particular applications: conventional
air spray gun for thin-film-build
requirements; airless gun for heavy
film application; and air-assisted airless
spray gun for a wide range of fluid
output.(b)
Reduce equipment cleaning by painting
with lighter colors before darker
ones.(b)
Examples of Costs and Savings
NA
Capital Investment: $3,000
Annual Savings: $3,390
Payback Period: 0,9 years(b)
NA
Capital Investment: $6,000
Annual Savings: $8,470
Payback Period: 0.7 years(b)
NA
Waste Reduction and
Other Information [References]
[Reference #81](b)
Waste Reduction: 66 gpy of
paint/primer residue. [Reference
#142](b)
[Reference #81](b)
Waste Reduction: 65 gpy of
paint/primer residue. Use paint
atomization spray equipment with
adjustable cross-sectional areas for
maximum paint transfer efficiency.
[Reference #142](b)
[Reference #81] (b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]) Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Production Planning and
Sequencing (Continued)
Process or Equipment
Modification
Pollution Prevention Method
Flush equipment with used solvent
before final cleaning with virgin
solvent. (b)
Use virgin solvents for final equipment
cleaning, then as paint thinner.(b)
Add wetting agents to the plating baths
to reduce adhesion of solution to the
parts.
Increase bath temperature to reduce
viscosity and improve drainage rate.
Increase drain time to allow parts to
drain after removal from bath.
Position workpieces on racks to
facilitate drainage.
Examples of Costs and Savings
NA
NA
NA
NA
Capital Investment: $0
Annual Savings: $3,350
NA
Waste Reduction and
Other Information [References]
Waste Reduction: 98% from 25,000
gal to 400 gal of paint cleanup solvents.
Company uses cleanup solvents in
formulation of subsequent batches.
[References #31](b)
[Reference #81](b)
[References #119, 120, 127, and 128]
[References #119, 120, 127, and 128]
Waste Reduction: Reduces drag-out of
copper into rinse water by 9 gpd.
[Reference #157]
[References #119, 120, 127, and 128]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g.. [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency. Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
lable y-s (continued;
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Process or Equipment
Modification (Continued)
Pollution Prevention Method
Place cadmium and zinc anode baskets
on removable anode bars that can be
lifted from the tank with an overhead
hoist.
Install overflow alarms on all process
tanks.
Mask part areas that should not be
plated.
Use brush plating for touch-up and
repair work.
Use chemical vapor deposition instead
of electroless plating.
Use spray rinsing to increase rinsing
efficiency.(b)
Use air agitation to improve rinsing
efficiency.
Reduce bath evaporation by covering
the surface with a blanket of
polypropylene balls.(b)
Examples of Costs and Savings
NA
NA
NA
NA
NA
NA
NA
NA
Waste Reduction and
Other Information [References]
Eliminates cadmium buildup causing
decanting of the solution.
[References #125 and 129]
[Reference #81](b)
Reduces buildup of dissolved metals
and drag-out. [Reference #126]
Reduces waste generation from
cleaning, demasking, and rinsing steps.
[Reference #130 and 131]
[Reference #134]
[Reference #81](b)
[Reference #129]
[Reference #81] (b)
U)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Process or Equipment
Modification (Continued)
Pollution Prevention Method
Continuously filter process baths to
extend their life.(b)
Work with customers to eliminate
unnecessary etching (e.g., etching to
shine parts).(b)
Use low concentration plating solutions
rather than midpoint concentrations to
reduce the total mass of chemical drag-
out.(b)
Use double drag-out followed by
recycle of the concentrated drag-out
solution to minimize rinse water
use.(b)
Use countercurrent rinses and
conductivity controls to reduce rinse
water flows.(b)
Examples of Costs and Savings
NA
NA
Capital Investment: Less than $30,000
Annual Savings: $l,300(b)
Annual Savings: $17,110 (based on
6,000 gpd)
$60,080 (based on
36,000 gpd)
$44,095 (based on
184,000 gpd)(b)
Annual Operating
Costs: $10.00/1,000 gal
Annual Savings: $170,000(b)
Annual Savings: $24,000 to $36,000
Waste Reduction and
Other Information [References]
[Reference #81, Sites 6233, 7159, and
16385[(b,c)
[Reference #81](b)
Based on a nickel plating operation
with 2,500 gpy of drag-out.
[Reference #81](b)
[Reference #81](b)
Waste Reduction: Reduced wastewater
discharge from 43,000 gpd to 8,000 gpd.
[Reference #81](b)
Five-stage countercurrent rinse for
chrome plating. [Reference #133]
ON
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, tnis
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Tnvirs FPA l^ffi /R-O") /nm A !»„...>_, 1001
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Process or Equipment
Modification (Continued)
Pollution Prevention Method
Use countercurrent rinses and
conductivity controls to reduce rinse
water flows.(b) (Continued)
Install countercurrent rinses with reuse
of the rinse water as make- up for the
plating bath (recovery rinsing).
Use ion beam enhanced technology for
chromium deposition in place of
chromium electroplating.
Examples of Costs and Savings
NA
NA
Capital Investment: $3,100
Annual Savings: $1,650
Payback Period: 1.8 years
NA
Waste Reduction and
Other Information [References]
Conductivity meters used for rinses.
[Sites 3960, 6028, 6233, 10843, 13682,
16385, 17309, and 19 102] (c)
[References #119, 120, 127, and 128,
Sites 914, 1220, 2100, 2306, 2335, 2634,
2948, 2958, 3793, 3862, 3960, 4000,
4979, 5410, 6233, 6306, 7159, 7175,
7361, 8099, 9081, 10283, 10565, 10843,
11286, 11350, 11507, 11579, 13682,
14043, 15000, 15908, 16385, 16589,
16905, 17309, 17325, 18802, 19698,
20532, 20813, 20914, 21142, 22208,
22436, 22734, 23653, and 24521](c)
Waste Reduction: Approximately
5,390,000 gpy of rinse water.
[Reference #153]
[Reference #181]
UJ
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
vp
oo
Pollution Prevention
Techniques
Process or Equipment
Modification (Continued)
Pollution Prevention Method
Eliminate use of cyanide in cadmium
electroplating operations by using
acidic cadmium-bearing electroplating
solutions.
Use spray-coating process to deposit
metal coatings on parts in place of
electroplating.
Use hard chrome plating process
consisting of a two-buss-bar plating
tank, conversion, zero discharge rinse,
system, plating bath purifier, and
scrubber system.
Use air knives to reduce drag-out from
electroplating baths.
Use on-demand rinsing (i.e., shut off
water discharge when rinse is not in
use) to reduce the quantity of rinse
water discharged.
Use flow restrictors to reduce the
quantity of rinse water discharged.
Examples of Costs and Savings
NA
NA
Capital Investment: $140,000
NA
NA
NA
Waste Reduction and
Other Information [References]
[Reference #183]
Process attains a 95% conversion
efficiency. Overspray can be collected
and recycled. [Reference #185]
Scrubber and rinse water are used to
replace bath solution lost due to
evaporation. [Reference #187]
[Sites 3960 and 11975](c)
[Sites 2306, 2948, 5410, 6306, 10674,
17325, 19225, 19698, 20532, 28653] (c)
[Sites 5410, 6233, 17325, 19225, 19698,
20532, and 20813](c)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Process or Equipment
Modification (Continued)
Pollution Prevention Method
Use squeegee to reduce drag-out.
Replace galvanizing processes requiring
high temperature and flux with one
that is low temperature and does not
require flux.(b)
Reduce exhaust-air flow rate to
minimize paint mist loss in paint booth.
Install an electrostatic powder coating
system to replace water curtain spray
paint booth.
Replace water curtain spray paint
booth with dry paint booth using dry
filtration of overspray.
Examples of Costs and Savings
NA
Capital Investment: $900,000
Annual Savings: 50% (as compared to
conventional
galvanizing) (b)
Capital Investment: $2,100
Annual Savings: $44,910
Payback Period: 0.1 years
Capital Investment: $78,440
Annual Savings: $10,230
Payback Period: 7.7 years
NA
Annual Savings: $l,500(b)
Waste Reduction and
Other Information [References]
[Sites 2306, and 17479](c)
Based on 1,000 kg/hr throughput.
[Reference #81](b)
Waste Reduction: 1,719 gpy of paint
sludge. [References #146]
Waste Reduction: 7,392 Ibs/yr of paint
solids and 8,840 Ibs/yr paint liquids.
[Reference #143]
[References #160 and 191, Sites 3862,
4884, 13103, 15632, 16385, 19019, and
19102] (c)
Waste Reduction: $3,000 gpy.
[Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics. EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Process or Equipment
Modification (Continued)
Pollution Prevention Method
Use transfer methods that reduce
material loss such as dip and flow
coating, electrostatic spraying, and
electrodeposition.(b)
Change from conventional air spray to
high-volume low-pressure (HVLP)
spray.
Examples of Costs and Savings
Capital Investment: Less than $30,000
Annual Savings: $15,000
Payback Period: 2 years(b)
Capital Investment: $4,400
Annual Savings: $25,410
Capital Investment: $58,320
Annual Savings: $11,080
Payback Period: 5.3 years
NA
Capital costs comparable to
conventional air spray equipment
Annual Savings: $42,000
Capital Investment: $1,500
Annual Savings: $240
Payback Period: 7 years
Waste Reduction and
Other Information [References]
[Reference #81](b)
Waste Reduction: 495 gpy of
paint/primer residue.
[Reference #142]
Waste Reduction: 580 gpy of paint and
primary 85 gpy of solvents.
[Reference #165]
[Sites 4979 and 17325](c)
Waste Reduction: 38% reduction in
lacquer paint usage. [Reference #148]
Waste Reduction: 12 gpy paint.
[Reference #156]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Process or Equipment
Modification (Continued)
Pollution Prevention Method
Change from conventional air spray to
high-volume low-pressure (HVLP)
spray. (Continued)
Install conductivity meters to reduce
corrosion preventive coating rinse
water discharge.
Use ion vapor deposition of aluminum
rather than a cadmium coating for
corrosion prevention.
Examples of Costs and Savings
Capital Investment: $5,000
Annual Savings: $8,500
Payback Period: 0.6 years
Capital Investment: $800
Annual Savings: $6,060
Payback Period: 0.2 years
NA
NA
NA
Waste Reduction and
Other Information [References]
Waste Reduction: 50% less filters
needed per year to capture paint
overspray. Paint transfer efficiency
improved by approximately 20%.
[Reference #158]
Waste Reduction: 1,750 Ibs per year of
paint overspray. [Reference #169]
[Sites 10843 and 13103] (c)
[Site 3960](c)
The aluminum coatings perform better
than cadmium coatings in acidic and/or
high temperature environments.
[Reference #189]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
VO
K)
Pollution Prevention
Techniques
Raw Material Substitution
Pollution Prevention Method
Substitute zinc for cadmium in
alkali/saline environments.(b)
Replace plated parts with brushed
aluminum or stainless steel parts (i.e.,
stainless steel in place of chromium-
plated parts).
Substitute solutions that don't contain
cyanide for cyanide-bearing
electroplating solutions. This
substitution, however, may not apply to
all types of cyanide-bearing
electroplating solutions.(b)
Substitute zinc chloride for zinc
cyanide.(b)
Substitute a nonchlorinated stripper for
methylene chloride.(b)
Examples of Costs and Savings
NA
NA
NA
NA
Capital Investment: $10,000
Annual Savings: $50,000
NA
NA
Waste Reduction and
Other Information [References}
Can eliminate use of cadmium in a
given shop. [Reference #118](b)
Eliminates plating processes and
associated wastes. May change product
appearance. [Reference #117]
Some non-cyanide solutions such as
cadmium plating cannot meet all
production requirements.
[Reference #119](b)
Waste Reduction: 1.67 gpd of cyanide-
bearing wastes. [Reference #136]
Replaced cyanide-based solution with
noncyanide alkaline zinc solution.
[Reference #140]
[Reference #81](b)
[Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001 A, January 1992.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Raw Material Substitution
(Continued)
Pollution Prevention Method
Replace hexavalent chromium baths
with trivalent chromium baths.
Use boric/sulfuric acid anodizing
instead of chromic acid anodizing.
Use nonchromium electroplating to
replace chromium electroplating.
Use deionized water for bath makeup
and for closed-loop recycling.
Use pure anodes to reduce bath
contamination.
Use iron phosphate coating instead of
zinc phosphate.
Examples of Costs and Savings
NA
NA
NA
NA
NA
NA
Waste Reduction and
Other Information [References]
Reduces treatment needs and effluent
toxicity. Lower tank temperature
reduces energy requirements.
[References #120 and 192, Site
10674](c)
Applicability varies for specific alloys
and end uses of product.
[Reference #121, Site 10674](c)
Substitutes include electroless nickel,
hard alloys, and molybdenum.
[References #117, 122, 123, and 124]
Extends useful life of plating baths.
[Reference #119]
Reduces sludge generated by less pure
anodes. [References #125 and 126]
Waste Reduction: 30,000 Ibs/yr of
sludge reduced to 6,000 Ibs/yr of
sludge. [Reference #138]
OJ
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Raw Material Substitution
(Continued)
Pollution Prevention Method
Use hot deionized water rather than
nickel acetate as an aluminum oxide
sealant following sulfuric acid
anodizing.
Replace cadmium electroplating with
nickel/zinc electroplating.
Use alternative coatings for solvent-
based paints to reduce volatile organic
materials use and emissions. (b)
Replace organic solvent-based paints
with high-solids coatings (this may
require modifying the painting process,
including high-speed/high-pressure
equipment, a paint distribution system,
and paint heaters). (b)
Replace organic solvent-based paints
with water-based coatings.(b)
Examples of Costs and Savings
Capital Investment: $1,020
Annual Savings: $3,094
Payback Period: 0.3 years
NA
30% net savings in applied costs per square
foot.(b)
NA
NA
Waste Reduction and
Other Information [References]
Waste Reduction: 2,275 gpy of spent
nickel acetate sealant solutions.
[Reference #167]
[Site 20813](c)
[Reference #151](b)
Waste Reduction: 41% in VOC
emissions. The VOC from the paint
decreased from 5.5 Ib/gal to 3 Ib/gal.
[Reference #81](b)
Waste Reduction: 87% reduction in
solvent emissions and decreased
hazardous waste production.
[References #81 and #154](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Raw Material Substitution
(Continued)
Pollution Prevention Method
Replace organic solvent-based paints
with water-based coatings.(b)
Replace organic solvent-based paints
with powder coatings.(b)
Examples of Costs and Savings
Capital Investment: $2,500
Annual Savings: $11,670
Payback Period: 0.2 years
NA
Capital Investment: $1.5 million
Payback Period: 2 years(b)
Capital Investment: $20,600
Annual Savings: $14,970 (includes
installation of a batch
spray booth for powder
coating)
Payback Period: 1.4 years
NA
NA
Waste Reduction and
Other Information [References]
Waste Reduction: 72 gpy of waste
paint and sludge and 66 gpy of spent
thinner. [Reference #83]
Waste Reduction: 75% in total
drummed hazardous waste. [Reference
#147]
Example is for a large, wrought iron
patio furniture company. [Reference
#81](b)
Waste Reduction: 72 gpy of waste
paint and sludge and 66 gpy of spent
thinner. [Reference #83]
[Site 6054](c)
[Sites 3862, 4884, 7972, 13103, 16632,
16385, 19019, and 19102](c)
sO
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Raw Material Substitution
(Continued)
Replace solvent-based paints
containing chromium with water-based
paints that do not contain chromium.
Capital Investment: $1,000
Annual Savings: $4,180
Payback Period: 0.2 years
Waste Reduction: 1,390 Ibs/year waste
solvent-based paint containing
chromium. [Reference #166]
Loss Prevention and
Housekeeping
To prevent spray gun leakage,
submerge only the front end (or fluid
control) of the gun into the cleaning
solvent.(b)
NA
[Reference #81](b)
Waste Segregation and
Separation
ON
Segregate wastewaters containing
recoverable metals from other
wastewater streams.(b)
NA
[Reference #81](b)
Segregate nonhazardous paint solids
from hazardous paint solvents and
thinner, (b)
NA
[Reference #81](b)
Recycling
Use electrolytic cells to recover metals
from waste plating solutions; applicable
to recovery of gold, silver, cobalt,
nickel, cadmium, copper, and zinc from
solutions with 100 mg/L to 1,000 mg/L
of metal, (b)
Capital Investment: $8,750 - $17,500(b)
Metal Recovery: 1-2 tpy. Metal losses
reduced by a factor of 100.
[Reference #81] (b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
>vO
-U
-J
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Regenerate anodizing and alkaline
baths with contemporary recuperation
of aluminum salts.(b)
Use electrodialysis to extend bath life.
Sell spent process solutions as make-up
to other solutions.(b)
Recycle used rinse waters into bath
makeup solutions for their respective
process baths.(b)
Reduce the quantity and toxicity of
final effluent by evaporation and
recovery of wastewater.(b)
Examples of Costs and Savings
Annual Savings: $0.02/m2 of aluminum treated
Annual Savings: $0.05/m2 (including sale of
recovered dry aluminum
sulfate)(b)
NA
Annual Savings: $16,300(b)
NA
Annual Savings: Greater than $100,000
Payback Period: Less than 1 year(b)
Capital Investment: $1.3 million
Annual Savings: $1.2 million(b)
Waste Reduction and
Other Information [References]
Based on a plant that previously
disposed of 180,000 L/yr of acid at
$0.07/L. [Reference #81](b)
Most often used with chromium plating
to remove iron, copper, and other
cations and convert Cr+3 to Cr+6.
[Reference #132]
[Reference #81](b)
[Sites 914, 2100, 2985, 3793, 3862, 3960,
6233, 6306, 7159, 9456, 16385, 18802,
19102, 19698, 20532, 20813, 23653, and
24521]
Reduced chromium consumption from
approximately 8,000 Ibs/ month to 200
Ibs/month by using a closed-loop
evaporator on the chromium bearing
rinse waters. [Reference #81](b)
Based on 350,000 m3/yr of wastewater.
[Reference #57](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Reduce the quantity and toxicity of
final effluent by evaporation and
recovery of wastewater.
(Continued) (b)
Examples of Costs and Savings
Capital Investment: $60,000
Annual Savings: $19,350
Payback Period: 3.8 years(b)
Capital Investment: $12,200
Annual Operating
Costs: $24,741
Annual Savings: $60,964(b)
Payback Period: 2-2.5 years(b)
NA
Capital Investment: $25,000(b)
Installed Cost: $35,680
Annual Operating
Cost: $9,160
Annual Savings: $21,000(b)
Waste Reduction and
Other Information [References]
Waste Reduction: Reduced chromic
acid replacement in chromium plating
bath by 4 Ibs/hr. [Reference #137](b)
Evaporative recovery used for nickel
plating rinse waters. [Reference #7](b)
84% reduction of chromium usage, 15-
20% sludge reduction. Company
installed an evaporative recovery unit
for a chromium plating process.
[Reference #81](b)
[Sites 6233](c)
[Reference #81](b)
System operates for 5,000 hrs/yr,
recovering 9,375 lbs/yr of chromic acid.
[Reference #81] (b)
oo
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Recycling (Continued)
Reduce the quantity and toxicity of
wastewater by reverse osmosis.(b)
vO
Capital Investment: $16,000
Payback Period: 1.67 years(b)
Waste Reduction: Almost 100% of
chemical and 90% of wastewater
recovered. Based on 260 L/hr of
wastewater. [Reference #81](b)
Capital Investment:
Payback Period:
$62,000 ($39,000 for
the reverse osmosis
unit)
Less than 2 years(b)
Company installed reverse osmosis unit
and evaporative heaters to recover
nickel and rinse water.
[Reference #31] (b)
Capital Investment: $8,500(b)
Waste Reduction: Approximately 85%
of the nickel drag-out. [Reference
#81](b)
Capital Investment:
Annual Operating
Cost:
$200,000 (330 ft2
membrane)
Large, due to high
pressures in system(b)
[Reference #81](b)
Capital Investment:
Annual Operation
Cost:
Annual Savings:
Payback Period:
$21,500
$9,113
$8,351
2.4 years(b)
Economic information for a Watts
nickel plating line with drag-out rates
greater than 1 gph. [Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Reduce the quantity and toxicity of
wastewater by reverse osmosis.
(Continued) (b)
Reduce the quantity and toxicity of
wastewater by ion exchange.(b)
Examples of Costs and Savings
NA
Capital Investment: $375,000
Payback Period: 2 years(b)
Payback Period: 5 years(b)
Capital Investment: $15,000 (1981)(b)
Capital Investment: $100,000
Annual Savings: $400,000 in recovered
silver
Capital Investment: $25,000
Annual Savings: $14,250
Payback Period: 1.75 years
NA
Waste Reduction and
Other Information [References]
[Site 17309] (c)
Waste Reduction: 92% recovery of ion
exchange-treated wastewater for reuse.
[Reference #81](b)
Nickel sulfate wastewater is treated by
ion exchange and returned to nickel
plating process. [Reference #19](b)
Ion exchange unit installed to recover
chromium. [Reference #81] (b)
Ion exchange resins used to recover
silver. [Reference #135]
Waste Reduction: 2,000 Ibs/yr of
hexavalent chromium waste. Used for
chromic acid anodizing line.
[Reference #139]
[Reference #163]
L/l
O
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Recycling (Continued)
Reduce the quantity and toxicity of
wastewater by ion exchange.
(Continued) (b)
NA
Waste Reduction: 50% reduction in
process water use. [Site 22734](c)
NA
[Sites 2100, 2306, 6028, 6233 and
Reduce the quantity and toxicity of
wastewater by electrolytic recovery.(b)
Capital Investment:
Annual Savings:
$8,500
$26,060 (in chemical
usage and process
water) (b)
Company implemented a high-surface
area (HSA) electrolytic reactor for
cadmium recovery. [Reference #81] (b)
so
Capital Investment:
Annual Savings:
$43,000
Treatment costs
eliminated; between 5
and 14 kg each of
silver, nickel, and
copper recovered
weekly.(b)
Company used fluidized bed electrolysis
to recover metals from electroplating
rinse waters. [Reference #81](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples at Costs and Savings
Waste Reduction and
Other Information [References]
Recycling (Continued)
Reduce the quantity and toxicity of
wastewater by electrolytic recovery.
(Continued) (b)
Capital Investment: $2,900
Annual Savings: $2,700
Waste Reduction: 75% reduction in
water consumption, 35% reduction in
metals discharge. Company installed
electrolytic recovery units on its copper,
nickel, lead, and tin electroplating lines
and counterflow rinses on all plating
lines. Majority of water reduction
probably due to countercurrent rinses.
[Reference #177]
Capital Investment:
Annual Savings:
$15,000 per unit
$9,700 per unit
tn
Is)
Capital Investment:
Payback Period:
$6,000
0.6 years
Applicable to cadmium/cyanide, silver/
cyanide, copper/cyanide, copper/
sulfate, and nickel/sulfamate
wastewaters. [Reference #186]
Waste Reduction: 88% reduction of
copper in rinse water. Company
converted flowing rinse after electroless
copper operation to a drag-out rinse
and used electrolytic recovery of
copper. [Reference #193]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Reduce the quantity and toxicity of
wastewater by electrolytic recovery.
(Continued) (b)
Reduce the quantity and toxicity of
wastewaters by electrodialysis with ion
exchange.(b)
Examples of Costs and Savings
Capital Investment: $6,300
NA
NA
NA
Capital Investment: $21,050 (15-cell-pair
unit)
Payback Period: 0.75 years(b)
Capital Investment: $109,600
Annual Savings: $26,000(b)
Waste Reduction and
Other Information [References]
Waste Reduction: 69% reduction of
copper in rinse water. Used air
agitation flow control for drag-out tank
and rinses following an electroless
copper plating operation. Used
electrolytic recovery unit to recover
copper. [Reference #194]
Electrolytic recovery unit used to
recovery cadmium from rinse water.
[Site 4043](c)
Electrolytic recovery unit used to
recover copper from rinse water. [Sites
2306 and 3862](c)
[Sites 3960, 7175, and 22734](c)
Company recovers gold from plating
rinse water using electrodialysis and ion
exchange. [Reference #81](b)
[Reference #87](b)
U)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Reduce the quantity and toxicity of
wastewaters by electrodialysis with ion
exchange, (b) (Continued)
Reduce the quantity and toxicity of
wastewaters by electrodialysis.
Use reactive rinsing in nickel
electroplating operations to reduce
rinse water use, improve plating
efficiency, and conserve process
chemicals, (b)
Examples of Costs and Savings
Capital Investment: $220,000
Annual Savings: $45,000(b)
Capital Investment: $120,000
Annual Savings: $129,000
Capital Investment: $30,000
NA
Capital Investment: $250 (for plumbing and
installation) (b)
Waste Reduction and
Other Information [References]
Based on a medium-size jewelry plating
and manufacturing company; updating
the existing water treatment facility
would have cost $500,000. [Reference
#81](b)
Waste Reduction: Recovered 85% of
nickel contained in nickel plating rinses.
[Reference #141]
[Reference #188]
[Sites 4208 and 10565] (c)
Rinse tanks operated at rate of 4 gpm
(reactive rinsing can eliminate 2 out of
3 plating line rinse tanks). [Reference
#81](b)
(n
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Pollution Prevention Method
Examples of Costs and Savings
Waste Reduction and
Other Information [References]
Recycling (Continued)
Recover phosphate from aluminum
bright dipping operations by reacting
acidic rinse with soda alkalies to yield a
trisodium phosphate solution. Filter
and cool the solution to crystallize the
trisodium phosphate, and recycle the
remaining rinse water.(b)
NA
Install a closed-loop system (using
electrodialysis) for repurification of
process water and reclamation of acid
for reuse on electroplating lines.
Capital Investment:
Annual Savings:
Payback Period:
$225,000
$107,000
2.1 years
Install ion-exchange and electrolytic
recovery units on copper electroplating
line.
Capital Investment: $15,000
Capital Investment: $320,000
Payback Period: 1 year
[Reference #81](b)
Waste Reduction: 96% reduction in
acid purchases, 91% reduction in
chemical disposal costs, and
98% reduction in water use and sewage
fees. [Reference #178]
Waste Reduction: 80% less copper
discharged from operation.
[Reference #128]
Waste Reduction: 69% less copper
discharged from operation.
[Reference #82]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Use centrifugation to separate paint
solids from paint booth water curtain.
Recycle water to paint booth.
Use batch distillation to recover xylene
from paint equipment cleanup, (b)
Use a solvent recovery still to recover
spent paint thinner from spray gun
cleanups and excess paint batches.(b)
Examples of Costs and Savings
Disposal costs reduced by 98%
NA
Annual Savings: $5,000
Payback Period: 13 months
Capital Investment: $6,000 (for a 15-gallon
capacity still)
Annual Savings: $3,600 (in new thinner
savings); $5,400 (in
disposal savings)
Payback Period: Less than 1 year(b)
Capital Investment: $4,360
Annual Savings: $5,400
Payback Period: 0.8 years
Capital Investment: $3,300
Annual Savings: $1,300
Waste Reduction and
Other Information [References]
Waste Reduction: Waste volume
reduced by 75%. [Reference #145]
[Sites 6038, 7175, 10674, and 17309] (c)
[Reference #31](b)
Waste Reduction: 75% (745 gal of
thinner recovered from 1,003 gal).
Based on 1,500 gpy of spent thinner
processed. [Reference #81](b)
Waste Reduction: 510 gpy of spent
thinner. [Reference #146]
[Reference #176]
ON
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-5 (Continued)
Examples of Source Reduction and Recycling Technologies
for Metal Coating and Deposition Operations (a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Method
Use N-methyl pyrrolidone (NMP), tri-
propylene glycol monomethyl ether
(TPM) and water solution to replace
water used for paint booth water
curtain.
Treat and reuse paint curtain water.
Examples of Costs and Savings
NA
NA
Waste Reduction and
Other Information [References]
Paint resin, pigments, and some paint
solvents can be recovered from the
NMP, TMP, water solutions system
uses less energy and results in cleaner
paint booth. [Reference #182]
[Sites 10283, 16905, and 17655]
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-6
Examples of Source Reduction and Recycling Technologies for Assembly Operations(a)
Pollution Prevention
Techniques
Training and Supervision
Process or Equipment
Modification
Pollution Prevention Methods
Avoid buying excess finishing material,
due to its short shelf-life.(b)
Use pressurized air mixed with a mist of
solvent to clean equipment.(b)
Use low-flow nozzles for spray cleaning
equipment.
Use solvent recovery to reduce the
emissions of volatile organics from curing
ovens.(b)
Use mechanical means to attach parts to
eliminate the use of adhesives.
Replace solvent-based adhesives with
water-based adhesives.
Skim contaminants from surface of
emulsifier and developer solutions used in
a dye penetrant testing operation.
Examples of Costs and Savings
NA
NA
Capital Investment: $270
Annual Savings: $13,000
Annual Savings: $400,000(b)
Capital Investment: $1,500
Annual Savings: $5,260
Payback Period: 0.3 years
Capital Investment: $31,740
Annual Savings: $25,690
Payback Period: 1.2 years
Capital Investment: $330
Annual Savings: $1,390
Payback Period: 0.24 years
Waste Reduction and
Other Information [References]
[Reference #81](b)
[Reference #81](b)
Waste Reduction: 11,000 gpy of
cleaning solvents. [Reference #150]
[Reference #81](b)
Waste Reduction: 330 gpy of
adhesives. [Reference #146]
Waste Reduction: 345 gpy of solvent
vapor. Solid waste generated is
nonhazardous. [Reference #84]
[Reference #161]
ex
NA - Not available in listed references.
(a) This infonnation was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
Table 9-6 (Continued)
Examples of Source Reduction and Recycling Technologies for Assembly Operations (a)
Pollution Prevention
Techniques
Raw Material Substitution
Loss Prevention and
Housekeeping
Waste Segregation and
Separation
Recycling
Pollution Prevention Methods
Use fluxless soldering to reduce the use of
halogenated solvents to remove flux
residues.(b)
Use rags to their full oil-absorbing
capacity, and use a laundering system to
clean oil-laden rags.(b)
Segregate solvent waste streams from
water streams.(b)
Recycle metal sludges through metal
recovery vendors.(b)
Use activated carbon to recover solvent
vapors, then recover the solvent from the
carbon by steam stripping, and distill the
resulting water/solvent mixture.(b)
Use a recovery system to recycle organic
solvents contained in air emissions.(b)
Use batch distillation to recover isopropyl
acetate generated during equipment
cleanup.(b)
Examples of Costs and Savings
NA
NA
NA
NA
Capital Investment: $817,000(b)
Annual Savings: $l,000(b)
Payback Period: 2 years(b)
Waste Reduction and
Other Information [References]
[Reference #151](b)
[Reference #81](b)
[Reference #81](b)
[Reference #81](b)
Waste Reduction: Releases of solvent
to the atmosphere were reduced from
700 kg/ton of solvent used to
20 kg/ton. [Reference #81](b)
[Reference #31](b)
[Reference #31](b)
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
(c) This information was obtained during site visits at the MP&M site(s) indicated in parenthesis.
-------
Table 9-6 (Continued)
Examples of Source Reduction and Recycling Technologies for Assembly Operations (a)
Pollution Prevention
Techniques
Recycling (Continued)
Pollution Prevention Methods
Use a methyl ethyl ketone solvent
recovery system to recover and reuse
waste solvents.(b)
Arrange an agreement with other small
companies to jointly recycle cleaning
wastes, (b)
Examples of Costs and Savings
Annual Savings: $43,000/yr(b)
NA
Waste Reduction and
Other Information [References]
Waste Reduction: 90% based on a
MEK recovery rate of 20 gpd.
[Reference #81](b)
[Reference #81] (b)
ON
O
NA - Not available in listed references.
(a) This information was obtained from a report prepared by EPA's Office of Pollution Prevention and Toxics (referred to as the "Bibliographic Report") and from other literature sources. All source
references are listed in Section 3.0 and are cited within brackets on this table (e.g., [Reference #1]). Information derived from the Bibliographic Report is denoted by footnote b. Cost, saving, and waste
reduction information shown on this table is based on case studies and reflects the successes reported by Metal Products and Machinery sites. Because specific applications are highly variable, this
information should be used as an indicator of how a particular pollution prevention technology has performed under specific circumstances.
(b) This information was obtained from Pollution Prevention Options in Metal Fabricated Products Industries, a Bibliographic Report. U.S. Environmental Protection Agency, Office of Pollution Prevention
and Toxics, EPA/560/8-92/001A, January 1992.
-------
9.3 References
1. U.S. Environmental Protection Agency, Office of Research and Development.
Guides to Pollution Prevention in the Fabricated Metal Products Industry.
EPA/625/7-90/006, Washington, DC, 1990.
2. U.S. Environmental Protection Agency, Office of Solid Waste and Emergency
Response. Waste Minimization in Metal Parts Cleaning. EPA/530-SW-89-049,
1989.
3. U.S. Environmental Protection Agency, Center for Environmental Research
Information. Meeting Hazardous Waste Requirements for Metal Finishers.
EPA/625/4-87/018, 1987.
4. California Alternative Technology Section and U.S. Environmental Protection
Agency. Waste Audit Study: Metal Finishing Industry. PIES #005-073-A, 1988.
5. California Alternative Technology Section and U.S. Environmental Protection
Agency. Waste Audit Study: Printed Circuit Board Manufacturers. PIES #005-
006, 1987.
6. State of Minnesota, State of Oregon, and U.S. Environmental Protection Agency.
Case Studies from the Minnesota Technical Assistance Program and the Oregon
Hazardous Waste Reduction Program, 1989.
7. North Carolina Pollution Prevention Program. Case Summaries of Waste
Reduction by Industries in the Southeast. PIES #112-003-A, 1989.
8. Metropolitan Water District of Southern California and the Environmental
Defense Fund. Source Reduction of Chlorinated Solvents - Electronic Products
Manufacture and Solvent Cleaning. PIES #609-008-A and #609-005-A, 1990.
9. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Opportunity Assessments Manual, EPA/625/7-88/0033,
Cincinnati, Ohio, 1988.
10. Connecticut Hazardous Waste Management Service, State of Connecticut. Waste
Minimization and Pollution Prevention: Metal Finishing - A Self Audit Manual,
September 1990.
11. Center for Hazardous Materials Research. Hazardous Waste Minimization
Manual for Small Quantity Generators in Pennsylvania. PIES #101-004, 1989.
9-61
-------
12. Johnson, J.T. A Comprehensive Strategy for an Overall Program of Metal
Working Fluid Management. Cincinnati Milacron Products Division, Cincinnati,
Ohio, 1985.
13. Schecter, R. and G. Hunt. Case Summaries of Waste Reduction by Industries in
the Southeast. North Carolina Pollution Prevention Pays Program. PIES #112-
003-A, Raleigh, NC, 1989. p. 40.
14. Traverse, L. Creative Source Reduction Techniques. Third Annual Massachusetts
Hazardous Waste Source Reduction Conference Proceedings. PIES #022-012,
Massachusetts Office of Safe Waste Management, Boston, MA, October 23, 1986.
15. Schecter, R. and G. Hunt. Case Summaries of Waste Reduction by Industries in
the Southeast. North Carolina Pollution Prevention Pays Program. PIES #112-
003-A, Raleigh, NC, 1989. p. 39.
16. Fromm, C.H., S. Budaraju, and S.A. Cordery, Jacobs Engineering Group.
Minimization of Process Cleaning Waste. In: Proceedings of the Solvent Waste
Reduction Alternatives Seminar. PIES #005-012-A-000, Washington, DC, March
1988.
17. Rodzewich, E.A. Source Reduction - Parts Cleaning. In: Proceedings of the
Solvent Waste Reduction Alternatives Seminar. PIES #005-012-A-000,
Washington, DC, March 1988.
18. Jacobs Engineering Group, Inc. for U.S. Environmental Protection Agency,
Hazardous Waste Engineering Research Laboratory, Office of Research and
Development. Waste Minimization Audit Report: Case Studies of Solvent
Wastes from Parts Cleaning and from Electronic Capacitor Manufacturing
Operations. PIES #010-003-A, Cincinnati, Ohio.
19. Institute for Local Self-Reliance. Engine and Plumbing Parts Manufacture, Case
Study 60, Proven Profits from Pollution Prevention: Case Studies in Resource
Conservation and Waste Reduction, Vol. II. PIES #306-001-A, Washington, DC,
1989.
20. North Carolina Department of Environment, Health, and Natural Resources:
Pollution Prevention Program. Managing and Recycling Solvents in the Furniture
Industry. PIES #034-018-A, Raleigh, North Carolina, May 1986.
21. Hackney. Pollution Prevention Challenge Grant Program, North Carolina
Department of Natural Resources. Pilot Study of Solvent Recovery for Use in
Paint Equipment Cleanup. PIES #034-050-A-000, December 1986.
9-62
-------
22. Frick, N.H. and G.W. Gruber, PPG Industries, Inc. Solvent Waste Minimization
by the Coatings Industry. PIES #800-01, Pittsburgh, Pennsylvania, March 1988.
23. California Department of Health Services, Alternative Technology Section, Toxic
Substances Control Division. Waste Audit Study: Automotive Paint Shops.
PIES #005-005, January 1987.
24. M. Drabkin and P. Sylvestri. Waste Minimization Audit Report: Case Studies of
Minimization of Solvent and Electroplating Wastes at a DOD Installation. PIES
#101-036-B, U.S. Environmental Protection Agency Hazardous Waste
Engineering Research Laboratory, Office of Research and Development,
Cincinnati, Ohio 1989.
25. Patterson, K.B. and D.E. Hunt. The Cyl-Sonic Cleaner: Aqueous Ultrafiltration
Cleaning Using Biodegradable Detergents. Process Technology '88: The Key to
Hazardous Waste Minimization, Air Force Logistics Command. PIES #100-
100-D, U.S. Air Force, AGMC/MAQSE, Newark Air Force Base, Ohio. August
15-18, 1988.
26. Smietana, T., Office of Safe Waste Management. Trichloroethylene Elimination
Case Study: Electric Furnace #2 Bright Anneal Line Industrial Metals
Department of Texas Instruments, Inc. In: Proceedings of the Third Annual
Massachusetts Hazardous Waste Source Reduction Conference. PIES #022-012,
October 23, 1986.
27. Massachusetts Department of Environmental Management, Office of Safe Waste
Management. Preliminary Report: Phase I Source Reduction Activities,
Southeast Platers Project, Case Study B. PIES #022-003-A, July 1988. p. 3.
28. North Carolina Department of Natural Resources and Community Development.
Water Conservation for Electroplaters: Counter-Current Rinsing. PIES #034-
024A, Raleigh, North Carolina, 1985.
29. North Carolina Department of Natural Resources and Community Development.
Water Conservation for Electroplaters: Rinse Tank Design. PIES #034-026A,
Raleigh, North Carolina, 1985.
30. Massachusetts Department of Environmental Management, Office of Safe Waste
Management. The Robbins Company: Wastewater Treatment and Recovery
System, A Case Study. PIES #034-0268, Raleigh, North Carolina, 1985.
31. Hunt, G., Accomplishments of North Carolina Industries - Case Summaries.
PIES #034-010, North Carolina Department of Natural Resources and
Community Development, Raleigh, North Carolina, January 1986, p. 22.
9-63
-------
32. Hazardous Waste Reduction Program of the Oregon Department of
Environmental Quality. The Tektonix Payoff. PIES #038-003-A-000, Salem,
Oregon, June 1988.
33. United Nations, Economic and Social Council, Economic Commission for Europe.
Compendium on Low-and Non-Waste Technology: Elimination of Chlorine by
the Use of Fumeless In-line Degreasing in the Aluminum Industry. PIES #400-
103, Geneva, Switzerland, 1983.
34. New Jersey Hazardous Waste Facilities Siting Commission, Hazardous Waste
Source Reduction and Recycling Task Force. A Study of Hazardous Waste
Source Reduction and Recycling in Four Industry Groups in New Jersey. Case
Study D4.1, PIES #031-001-A, Newark, New Jersey, April 1987. p. 30.
35. Evanoff, S.P, et. al. Alternatives to Chlorinated Solvent Degreasing - Testing,
Evaluation, and Process Design. In: Proceedings of Process Technology '88: The
Key to Hazardous Waste Minimization, Air Force Logistics Command. PIES
#100-100-D, Sacramento, California. August 15-18, 1988.
36. Hunt, G., et al. North Carolina Department of Natural Resources and Community
Development. Accomplishments of North Carolina Industries - Case Summaries.
PIES #034-010, Raleigh, North Carolina, January 1986. p. 22.
37. United Nations, Economic and Social Council, Economic Commission for Europe.
Compendium on Low- and Non-Waste Technology: A Low-Waste Electroplating
Process. PIES #400-125, Geneva, Switzerland, 1985.
38. Huisingh, D., L. Martin, H. Hilger, and N. Seldman. Proven Profit from Pollution
Prevention. Case Study 26. PIES #306-001-A. The Institute for Self-Reliance,
Washington, D.C., 1985. p. 103.
39. McRae, G.F. In-Process Waste Reduction: Part 1 - Enviroscope, Plating and
Surface Finishing, June 1988.
40. Wigglesworth, D., et.al. Alaska Health Project. Waste Reduction Assistance
Program (WRAP) On-Site Consultation Audit Report: Electroplating Shop.
PIES #002-016-A-001, Anchorage, Alaska, April 7, 1987. p. 17.
41. Saltzberg, E., Ph.D. Science Applications International Corporation. Methods to
Minimize Wastes From Electroplating Facilities. In: Proceedings of Process
Technology '88: The Key to Hazardous Waste Minimization, Air Force Logistics
Command. PIES #100-100-D, Sacramento, California. August 15-18, 1988.
9-64
-------
42. Hubbard Enterprises, San Diego County, Department of Health Services.
Minimizing Waste from an Electroplating Operation, Pollution Prevention, A
Resource Book for Industry. PIES #005-079-A-000, San Diego, California, 1990.
43. Kohl, J., et. al. Reducing Hazardous Waste Generation with Examples from the
Electroplating Industry. North Carolina State University, School of Engineering,
Raleigh, North Carolina, 1986.
44. Massachusetts Department of Environmental Management, Office of Safe Waste
Management. Source Reduction Recommendations for Precious Metal Platers.
PIES #002-012, Boston, Massachusetts, April 1988.
45. Achman, D. Reducing Chromium Losses from a Chromium Plating Bath.
Minnesota Technical Assistance Program Summer Intern Report. PIES #709-030,
Summer 1987.
46. United Nations Economic and Social Counsel. Use of an Evaporator in
Chromium Electroplating, Compendium on Low- and Non-Waste Technology.
Monograph ENV/Wp.2/5/Add.47. PIES #400-125, Geneva, Switzerland, 1988.
47. Vaaler, L.E., Office of Safe Waste Management. Prospects for Developing
Substitutes for Cyanide-Containing Electroplating Baths. In: Proceedings of the
Third Annual Massachusetts Hazardous Waste Source Reduction Conference.
PIES #022-012, Boston, Massachusetts, October 23, 1986.
48. U.S. Environmental Protection Agency, Office of Research and Development,
Risk Reduction Engineering Laboratory. Waste Minimization Audit Report:
Case Studies of Minimization of Cyanide Waste from Electroplating Operations,
Project Summary. PIES #101-023-B, Cincinnati, Ohio, January 1988.
49. Minnesota Technical Assistance Program. Metal Recovery: Metal Finishing
Shop. PIES #709-017, Minneapolis, Minnesota, September 1988.
50. Pajunen, P. Eco-Tech Ltd., and E. Schneider, Hewlett Packard, American
Electroplaters and Surface Finishing Society and U.S. Environmental Protection
Agency. Copper and Nickel Removal in Printed Circuit Board Processing by Ion
Exchange and Electroforming. In: Proceedings for the Ninth AESF/EPA
Conference on Environmental Control for the Metal Finishing Industry, January
25-29, 1988.
51. Nadeau, T., et. al. Copper, Nickel and Chrome Recovery in a Jobshop to
Eliminate Waste Treatment and Sludge Disposal. In: Proceedings of the Third
Annual Massachusetts Hazardous Waste Source Reduction Conference, Office of
Safe Waste Management. PIES #022-012, Boston, Massachusetts, October 23,
1986.
9-65
-------
52. Minnesota Technical Assistance Program. Metal Recovery: Ion Exchange. PIES
#709-019, Minneapolis, Minnesota, September 1988.
53. Tran, T.V., et al. Recovery of Nickel Salts by Electrodialysis Reversal Process,
Presented at 73rd Annual AESF Technical Conference and Exhibit of Surface
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57. United Nations, Economic and Social Council, Economic Commission for Europe.
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58. United Nations, Economic and Social Council, Economic Commission for Europe
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60. Minnesota Technical Assistance Program, University of Minnesota. Metal
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67. Sutler, H. Umweltbundesamt. Low-Waste Technologies in the Federal Republic
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68. North Carolina Department of Environment, Health, and Natural Resources:
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69. Hazardous Waste Reduction Program of the Oregon Department of
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70. Manzione, M. Brown and Caldwell Consulting Engineers. Waste Minimization
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71. Hackney, Pollution Prevention Challenge Grant Program, North Carolina
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72. California Department of Health Services, Alternative Technology Section, Toxic
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73. U.S. Environmental Protection Agency, Hazardous Waste Engineering Research
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74. Office of Management and Budget. Handbook of Standard Industrial
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75. U.S. Environmental Protection Agency, Office of Water. Development Document
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76. U.S. Environmental Protection Agency, Office of Research and Development.
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78. U.S. Environmental Protection Agency, Office of Solid Waste. Industrial
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79. U.S. Environmental Protection Agency, Office of Solid Waste. Waste
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80. U.S. Environmental Protection Agency. Development Document for Effluent
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81. U.S. Environmental Protection Agency, Office of Solid Waste. Pollution
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83. U.S. Environmental Protection Agency, Office of Research and Development.
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84. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Assessment for a Manufacturer of Heating, Ventilating, and
Air Conditioning Equipment. Environmental Research Brief. EPA/500/M-
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85. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Assessment for a Manufacturer of Compressed Air
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86. U.S. Environmental Protection Agency, Office of Research and Development.
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87. U.S. Environmental Protection Agency, Office of Research and Development.
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Environmental Research Brief. EPA/600/S-92/014, Cincinnati, Ohio, April 1992.
88. Massachusetts Office of Technical Assistance. Pollution Prevention Case Study:
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89. Hause, T., Spartan Chemical Co., Inc. Get the Most from Today's Cookouts.
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90. Turbo Conveyor. Recycling Cuts Coolant Costs 67%, In Modern Machine Shops.
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91. National Screw Machine Products Association. Project Zero. White Paper
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92. U.S. Environmental Protection Agency, Office of Research and Development.
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93. U.S. Environmental Protection Agency, Office of Research and Development.
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94. U.S. Environmental Protection Agency, Office of Research and Development.
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and Ice Storage Bins. Environmental Research Brief. EPA/600/S-92/012,
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95. U.S. Environmental Protection Agency, Office of Research and Development.
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96. Deushlo, A., D.P., Inc. Diffusion Dialysis. An Economical Technology for
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97. Tham, J. and L. LankFord. Reducing Use of Ozone-Depleting Substances and
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98. The Hazardous Waste Consultant. CO2 Blasting for Metal Cleaning Operations.
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102. ASM Committee on Acid Cleaning. Acid Cleaning of Iron and Steel. Metals
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103. California Department of Health Services, Alternative Technology Section. Toxic
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104. Williams, M., R. Deshmukh, and D. Bhattachargya. Separation of Hazardous
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105. Hill, L., Parker Haunifin Corporation. Replacing Methylene Chloride Degreasing:
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106. Connecticut Technical Assistance Program. Case Study: The United Illuminating
Company. ConnTAP Quarterly, Vol. 5, No. 2, Hartford, Connecticut, Spring
1992.
107. Minnesota Technical Assistance Program. Deburring Operations Replaces Vapor
Degreaser for Cleaning Metal Parts. MnTAP SOURCE, Vol. 7, No. 3,
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108. U.S. Environmental Protection Agency, Office of Air and Radiation. Alternatives
for CFC-113 and Chloroform in Metal Cleaning. Washington, D.C., June 1991.
109. Schmitz, W. McDonnell Aircraft Company. CO2 Pellet Blasting for Paint
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110. Wasson, N. and M. Haas, U.S. Air Force. Sodium Bicarbonate Blasting for Paint
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111. Salerro, R. High Pressure Supercritical Carbon Dioxide Efficiency in Removing
Hydrocarbon Machine Coolants from Metal Coupons and Component Parts. In:
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Energy and U.S. Air Force, Phoenix, Arizona, December 4-7, 1990.
112. Hermansen, R., Hughes Aircraft Company. Development of a Solvent Database
Software Program. In: Proceedings/Compendium of Papers: Solvent
Substitution. U.S. Department of Energy and U.S. Air Force, Phoenix, Arizona,
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113. Bower, M., APS Materials, Inc. and L. Brown and J. Springer, U.S. Environmental
Protection Agency. Chemical Substitution for 1,1,1-Trichloroethane and Methanol
In: Proceedings/Compendium of Papers: Solvent Substitution. U.S. Department
of Energy and U.S. Air Force, Phoenix, Arizona, December 4-7, 1990.
114. Burrell, M., Waste Minimization Company. The Successful Implementation of a
Solvent Recovery Program. In: Proceedings/Compendium of Papers: Solvent
Substitution. U.S. Department of Energy and U.S. Air Force. Phoenix, Arizona,
December 4-7, 1990.
115. Suolen, M., Oakite Products, Inc. Replacing Petroleum-Based Oils in Metal
Forming Operations. Chlorinated Solvent (CFC) Replacement Seminar.
Rochester, New York, October 30, 1991.
116. Miller, G., T. Lindsey, A. Ocker, and M. Miller, U.S. Environmental Protection
Agency, Risk Reduction Engineering Laboratory. Evaluation of Ultrafiltration to
Recovery Aqueous Iron Phosphating/Degreasing Bath. Cincinnati, Ohio,
May 1993.
117. U.S. Environmental Protection Agency. Guide to Clean Technology: Alternative
Metal Finishes (Draft). July 1992.
118. Grahm, G. and M. Patry. Oklahoma City Air Logistics Center - Propulsion
Directorate. Hazardous Waste Minimization Report. Undated.
119. Metal Finishing Guidebook and Directory Issue, 1992. 60th Guidebook Directory
Issue, Hackensack, New Jersey, 1992.
120. U.S. Environmental Protection Agency. Guides to Pollution Prevention, the
Printed Circuit Board Manufacturing Industry.
121. Koop, R. and Y. Moji. Boric/Sulfuric Acid Anodize-Alternative to Chronic Acid
Anodize. In: Proceedings of the 28th Annual Aerospace/Airline Plating and
Metal Finishing Forum and Exposition. April 20-23, 1992.
122. Jeannenne, R.A. EN for Hard Chromium. Products Finishing, January 1990.
123. Kusher, B. Coating Alternatives to Chrome Plating. In: Proceedings of the 28th
Annual Aerospace/Airline Plating and Metal Finishing Forum and Exposition.
April 20-23, 1992.
124. Langan, J. Alternative for Tank Chromium Using Brush Plating. AESF SURFIN
Conference. June 1992.
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125. American Society of Metals. Metals Handbook. Surface Cleaning, Finishing, and
Coating. Vol. 5. Metals Park, Ohio.
126. ICF Technology, Incorporated. New York State Waste Reduction Guidance
Manual. Prepared for: New York State Department of Environmental
Conservation. Albany, New York, March 1989.
127. Cushnie, G.C. Electroplating Wastewater Pollution Control Technology. Noyes
Publications, Park Ridge, New Jersey, 1985.
128. City of Palo Alto. Regional Water Quality Control Plant. Pollution Prevention
Review: Mantex Circuits, Inc. Palo Alto, California, January 5, 1994.
129. CH2M Hill. Engineering Evaluation of Plating Shop Renovation for the 243-G
Bay Electroplating Facility (McClellan AFB). Contract No. F0469900035, Task
No. 5008, July 1991.
130. Rubinstein, M. Electrochemical Metabolizing - Principals and Practices. Van
Nostrand Reinhold, New York, New York 1987.
131. Norris, J. Brush Anodizing in the Aircraft/Aerospace Industries, Plating and
Surface Finishing, August 1992.
132. Cushnie, G. and W. Anderson. Removal of Metal Cations from Chromium
Plating Solutions. In: Proceedings of the 10th AESF/EPA Conference on
Environmental Control for the Metal Finishing Industry, January 1989.
133. Foss, L. Foss Plating Company. Closed Loop Plating System for Waste
Minimization. Metal Waste Management Alternatives, 1989 Symposium
Proceedings, California Department of Health Services, Pasadena, California,
August 1989.
134. Jacobs Engineering Group, Inc. for California Department of Health Services,
Toxic Substances Control Division. Reducing California's Metal-Bearing Waste
Streams. Pasadena, California, August 1989.
135. Abbott, D. A Systems Approach to Electroplating Waste Minimization. Case
Studies in Waste Minimization. Government Institutes, Inc., Rockville, Maryland,
October 1991.
136. U.S. Environmental Protection Agency, Office of Research and Development.
Plant C. Waste Minimization Opportunity Assessment. Case Studies in Waste
Minimization. Government Institute, Inc., Rockville, Maryland, October 1991.
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137. U.S. Environmental Protection Agency, Office of Research and Development.
Environmental Regulations and Technology: The Electroplating Industry.
EPA/625/10-85/001, September 1985.
138. Connecticut Technical Assistance Program. Iron Phosphate Coating Can
Eliminate Zinc from Waste Stream. ConnTAP Quarterly, Vol. 3, No. 3, Hartford,
Connecticut, Summer 1993.
139. Connecticut Technical Assistance Program. Manufacturer Produces Savings Using
Closed-Looped System. ConnTAPP Quarterly, Vol. 3, No. 3, Hartford,
Connecticut, Summer 1990.
140. Minnesota Technical Assistance Program. Peerless Chain Company Eliminates
Use of Cyanide-Based Plating Solution. MnTAP Source, Vol. 6, No. 4,
Minneapolis, Minnesota, Fall 1991.
141. Connecticut Technical Assistance Program. Waste Minimization System Saves
Bridgepoint Company $129,000 Annually. ConnTAP Quarterly, Vol. 2, No. 3,
Hartford, Connecticut, Summer 1989.
142. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Assessment for a Manufacturer of Outdoor Illuminated Signs.
Environmental Research Brief. EPA/600/M-91/016, Cincinnati, Ohio, July 1991.
143. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Assessment for a Manufacturer of Permanent-Magnet. D.C.
Electric Motors. Environmental Research Brief.
144. Park, G. RI Department of Environmental Management. Viteratary Solution
Recycling: A Case Study in Pollution Prevention. In: Proceedings of the 1992
Rhode Island Pollution Prevention Conference and Exposition, Providence, Rhode
Island, September 30 - October 1, 1992.
145. Centrifuge Reduced Paint Solid Waste. Cut Disposal Fees. Pollution
Engineering. October 15, 1992. pp. 16-17.
146. Young, S., Minnesota Technical Assistance Program. Reducing Overspray in a
Conventional Air-Atomizing Paint System. Minnesota Waste Management Board.
Minneapolis, Minnesota, 1987.
147. U.S. Environmental Protection Agency, Office of Research and Development.
Plant A Waste Minimization Opportunity Assessment. In: Case Studies in Waste
Minimization. Government Institute, Inc., Rockville, Maryland, October 1991.
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148. Frady, M., Lilly Industries, Inc. HVLP Spray Gun Applications. Focus Waste
Minimization, Issue No. 12, North Carolina Department of Environmental Health,
and Natural Resources. Raleigh, North Carolina, Spring/Summer 1992.
149. Connecticut Technical Assistance Program. Case Study Bead Industries
Bridgeport. ConnTAP Quarterly, Vol. 4, No. 3, Hartford, Connecticut,
Summer 1991.
150. Minnesota Technical Assistance Program. Case Study. Spray Nozzle Selection
Reduces Solvent Waste. MnTAP SOURCE, Vol. 6, No. 3,
Minneapolis, Minnesota, Summer 1991.
151. Hoskins, M., Sandia National Laboratories. Reduction of Solvent Use Through
Fluxless Soldering. In: Proceedings/Compendium of Papers: Solvent
Substitution. U.S. Department of Energy and U.S. Air Force. Phoenix, Arizona,
December 4-7, 1990.
152. U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics.
Pollution Prevention Options in Metal Fabricated Products Industries.
EPA/560/8-92/001a, January 1992.
153. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Reduction Activities and Options for a Manufacturer of Hardened Steel
Gears. Environmental Research Brief. EPA/600/S-92/057, Cincinnati, Ohio,
October 1992.
154. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Reduction Activities and Options for a Remanufacturer of Automobile
Radiators. Environmental Research Brief. EPA/600/S-92/051, Cincinnati, Ohio,
October 1992.
155. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Reduction Activities and Options for a Fabrication and Finisher of Steel
Computer Cabinets. Environmental Research Brief. EPA/600/S-92/044,
Cincinnati, Ohio, October 1992.
156. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Reduction Activities and Options for an Autobody Repair Facility.
Environmental Research Brief. EPA/600/S-92/043, Cincinnati, Ohio, October
1992.
157. U.S. Environmental Protection Agency, Office of Research and Development.
Modifications to Reduce Drag-Out at a Printed Circuit Board Manufacturer.
Project Summary. EPA/600/SR-92/114, Cincinnati, Ohio, October 1992.
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158. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Reduction Activities and Options for Manufacturer of Commercial Dry
Cleaning Equipment. Environmental Research Brief. EPA/600/S-92/062,
Cincinnati, Ohio, October 1992.
159. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Opportunity Assessment: Fort Riley, Kansas. Project
Summary. EPA/600/S2-90/031, Cincinnati, Ohio, August 1990.
160. U.S. Environmental Protection Agency, Office of Research and Development.
Users Guide for the Conversion of Navy Paint Spray Booth Particulate Emission
Control Systems from Wet to Dry Operation. Project Summary. EPA/600/S2-
90/008, Research Triangle Park, North Carolina, May 1990.
161. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Opportunity Assessment: Scott Air Force Base. Project
Summary. EPA/600/S2-91/054, Cincinnati, Ohio, December 1991.
162. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Opportunity Assessment: Philadelphia Navy Shipyard.
Project Summary. EPA/600/S2-90/046, Cincinnati, Ohio, February 1991.
163. U.S. Environmental Protection Agency, Office of Research and Development.
Recovery of Metals from Sludges and Wastewaters. EPA/600/S2-91/041,
Cincinnati, Ohio, September 1991.
164. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Assessment for a Metal Parts Coating Plant. Environmental
Research Brief. EPA/600/M-91/015, Cincinnati, Ohio, July 1991.
165. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Assessment for Manufacturer of Rebuilt Railway Cars and
Components. Environmental Research Brief. EPA/600/M-91/017, Cincinnati,
Ohio, July 1991.
166. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Assessment for a Manufacturer of Cutting and Welding
Equipment. Environmental Research Brief. EPA/600/S-92/029, Cincinnati,
Ohio, September 1992.
167. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Assessment for a Manufacturer of Finished Metal
Components. Environmental Research Brief. EPA/600/S-92/030, Cincinnati,
Ohio, September 1992.
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168. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Assessment for a Manufacturer of Machined Parts.
Environmental Research Brief. EPA/600/S-92/031, Cincinnati, Ohio, September
1992.
169. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Assessment for a Manufacturer of Sheet Metal Components.
Environmental Research Brief. EPA/600/S-92/037, Cincinnati, Ohio, September
1992.
170. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Minimization Assessment for a Manufacturer of Penny Blanks and Zinc
Products. Environmental Brief. EPA/600/S-92/037, Cincinnati, Ohio, September
1992.
171. U.S. Environmental Protection Agency, Office of Research and Development.
Waste Reduction Activities and Options for a Manufacturer of Commercial
Refrigeration Units. Environmental Research Brief. EPA/600/S-92/047,
Cincinnati, Ohio, October 1992.
172. Haimowitz, S. Process Profiles: Recover Metals-Laden. Chemical Engineering.
October 1993. p. 31.
173. DOE Tests Hail Ultrasonic Cleaning with Aqueous Detergents. Aero
Environmental Report. October 1, 1993. p.8.
174. Connecticut Technical Assistance Program. Process Change Eliminates Waste.
Site Visit Team Assists Manufacture's Cost Contaminant Measures. ConnTAP
Quarterly, Vol. 1, No. 1, Hartford, Connecticut, Winter 1994.
175. Connecticut Technical Assistance Program. Wallingford Manufacturer Blazes
Pollution Prevention Trail, Discovers 2.8 Year Payback for Eliminating CFCs.
ConnTAP Quarterly, Vol. 6, No. 4, Hartford, Connecticut, Fall 1993.
176. Minnesota Technical Assistance Program. Reducing Wastes at an Autobody
Repair Shop. MnTAP SOURCE, Vol. 8, No. 4, Minneapolis, Minnesota, Fall
1993.
177. Commonwealth of Massachusetts, Office of Technical Assistance. Metals
Recovery and Wastewater Reduction at Hi-Tech Gold Plating Corporation.
Toxics Use Reduction Case Study. Boston, Massachusetts. Undated.
178. Commonwealth of Massachusetts, Office of Technical Assistance. Chemical and
Water Use Reduction at Poly-Plating, Inc. Toxics Use Reduction Case Study.
Boston, Massachusetts. Undated.
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179. Commonwealth of Massachusetts, Office of Technical Assistance. Immortal
Etchants. Boston Massachusetts. Undated.
180. Commonwealth of Massachusetts, Office of Technical Assistance. G.F. Wright
Ends H2SO4 Use for Wire Pickling, Cuts Use by 95 Percent. Draft Toxics Use
Reduction Case Study. Boston, Massachusetts. Undated.
181. Dentchman, A.H., Beamalloy Corporation. Beamalloy Corporation Announces
New Non-Toxic, Hand Chrome Coating Process. News Release. Dublin, Ohio,
July 10, 1992.
182. Walsh, W.C., BASF Corporation Chemicals Division. Alternative Paint Trapping,
Fluid for Use in Recirculating Water Automotive Paint Booths. Parsippany, New
Jersey, 1993.
183. U.S. Army Corps of Engineers. Non-Cyanide Electroplating. Installation
Restoration and Hazardous Waste Control Technologies, 1992. p. 201.
184. U.S. Army Corps of Engineers. Non-Cyanide Metal Stripper Replacement
Program. Installation Restoration and Hazardous Waste Control Technologies,
1992. p. 203.
185. U.S. Army Corps of Engineers. Spray-Casting to Replace Electroplating.
Installation Restoration and Hazardous Waste Control Technologies, 1992. p.
207.
186. U.S. Army Corps of Engineers. Electrolytic Recovery of Metal/Cyanide
Wastewaters. Installation Restoration and Hazardous Waste Control
Technologies, 1992. p. 203.
187. U.S. Army Corps of Engineers. Hard Chrome Plating Installation Restoration
and Hazardous Waste Control Technologies, 1992. p. 217.
188. U.S. Army Corps of Engineers. Electrodialysis of Chromic Acid Plating Solutions.
Installation Restoration and Hazardous Waste Control Technologies, 1992. p.
219.
189. U.S. Army Corps of Engineers. Ion Vapor Deposition (IVD) Substitution of
Aluminum for Cadmium. Installation Restoration and Hazardous Waste Control
Technologies, 1992. p. 223.
190. U.S. Army Corps of Engineers. Recycle of Spent Abrasive Into Asphaltic
Concrete. Installation Restoration and Hazardous Waste Control Technologies,
1992. p. 225.
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191. U.S. Army Corps of Engineers. Conversion of Paint Booth Filtration from Wet to
Dry. Installation Restoration and Hazardous Waste Control Technologies, 1992.
p. 247.
192. General Services Administration, Region 6. Briefing Package for an Alternative
Coatings Workshop. Kansas City, Missouri, December 3, 1993.
193 City of Palo Alto. Regional Water Quality Control Plant. Pollution Prevention
Review: Technitron, Inc. Palo Alto, California, January 5, 1994.
194. City of Palo Alto. Regional Water Quality Control Plant. Pollution Prevention
Review: Davila International Circuits, Inc. Palo Alto, California, January 5, 1994.
NOTE: Information on pollution prevention is available through EPA's
EnviroSense clearinghouse. The EnviroSense clearinghouse contains
technical, policy, programmatic, legislative, and financial information on
pollution prevention efforts in the United States and abroad. The
EnviroSense clearinghouse may be accessed by mail, telephone, or the
EnviroSense Bulletin Board System, a free 24-hour computer bulletin
board. Technical support information on the use on the EnviroSense BBS
may be obtained by calling (703) 908-2007.
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10.0 TECHNOLOGY OPTIONS
10.0 TECHNOLOGY OPTIONS
This section describes the five technology options which were used in developing the
Metal Products and Machinery (MP&M) Phase I effluent limitations guidelines and
standards. Section 10.1 identifies the technologies considered for the MP&M Phase I
technology options, including a brief description of each technology, a summary of the
demonstration status of each technology, and a summary of the technologies included in
the technology options. Section 10.2 summarizes the methodology EPA used to select
the technologies included in the options, and describes each technology option. Section
10.3 presents a detailed description of each technology included in the options. The
technologies included in each option were selected for development of the MP&M Phase
I effluent limitations guidelines and standards. These technologies are not required for
compliance with the MP&M Phase I effluent guidelines; sites can install any technology
as long as the site achieves the final effluent limitations. These technology options were
used to estimate compliance costs (see Section 12.0) and pollutant loadings and
reductions (Section 13.0) for the MP&M Phase I effluent guidelines.
The MP&M Phase I technology options consist of groups of source reduction, recycling,
and wastewater treatment technologies identified to reduce or eliminate the creation or
discharge of pollutants from MP&M sites. The technologies considered for the
technology options were identified from responses to the MP&M data collection
portfolios (DCPs), MP&M site visits and sampling episodes, and technical literature
(including case studies and development documents for previously promulgated metals
industry regulations).
10.1 Technologies Considered
As discussed in Section 6.0, MP&M Phase I sites generate wastewaters containing oils
(including organic pollutants), cyanide, and metals. Many different types of technologies
are used in the MP&M industry to control and treat these wastewaters, including both
in-process source reduction and recycling technologies and end-of-pipe treatment and
disposal technologies. These technologies have been classified into one of the four tiers
of the Environmental Management Hierarchy (EMH) from the Facility Pollution
Prevention Guide (1). This hierarchy attempts to prioritize technologies in order of
importance or benefit to the environment from source reduction (highest priority) to
disposal (lowest priority). Tables 10-1 through 10-3 present technologies considered for
the MP&M Phase I technology options grouped by their EMH classification as follows:
1. Table 10-1: Source reduction technologies - EMH tier 1;
2. Table 10-2: Recycling technologies - EMH tier 2; and
3. Table 10-3: End-of-pipe treatment and disposal technologies -
EMH tiers 3 and 4.
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The tables present the following for each technology: a brief technology description; the
number of sites visited at which the technology was observed; the number of MP&M
Phase I model site DCP respondents reporting using the technology; the estimated
number of sites in the MP&M Phase I industry using the technology (based on responses
to the DCP scaled to the entire industry); and additional comments noting if the
technology was included in the MP&M technology options (as discussed in Section 10.2)
and, where appropriate, reasons why the technology was not included in the MP&M
technology options.
The demonstration status of source reduction and some recycling technologies in the
MP&M Phase I industry was not quantifiable from data in the DCPs. Therefore,
Tables 10-1 and 10-2 do not always present estimates of the number of MP&M sites
performing each of these technologies. However, as shown on these tables, EPA
observed these technologies during visits to MP&M sites. The most frequently observed
source reduction and recycling technologies were:
• Centrifugation of machining coolants;
• Conductivity probes;
• Countercurrent cascade rinsing;
• Drag-out rinsing;
• Electrolytic recovery;
• Flow restrictors;
• In-tank filtration;
• Ion exchange; and
• Regeneration of process baths.
In addition, many of the sites visited employed plant maintenance and good
housekeeping practices that resulted in source reduction.
As shown in Table 10-3, the most common end-of-pipe treatment technologies in the
MP&M Phase I industry are:
• Chemical emulsion breaking;
• Chemical precipitation and settling;
• Chemical reduction of hexavalent chromium;
• Cyanide destruction through alkaline chlorination;
• Gravity settling of wastewater (without chemical addition);
• Gravity thickening of sludge;
• Multimedia filtration (including sand filtration);
• Neutralization (without solids removal);
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• Oil skimming; and
• Pressure filtration of sludge.
In addition, an estimated 2,826 of the 10,061 water discharging MP&M sites, contract
haul some of their wastewater for off-site treatment and disposal. Many sites with
treatment technologies in place also contract haul wastewater treatment sludges for off-
site disposal.
10.2 Technology Options
EPA developed five technology options for the MP&M Phase I industry, based on the
technologies listed in Tables 10-1 through 10-3 and the following general criteria.
• Demonstrated status at MP&M Phase I sites.
• Demonstrated performance for controlling and treating MP&M
Phase I wastewater, including an assessment of pollution prevention
benefits. This assessment was based on the EMH classification of
each technology.
EPA considered a technology to be demonstrated in the MP&M Phase I industry if the
technology was observed during at least one MP&M site visit or reported by at least one
MP&M Phase I DCP respondent, and was considered by EPA to be applicable to
MP&M Phase I wastewaters. EPA evaluated the performance of each technology using
available analytical data from MP&M sampling episodes, analytical data from previously
promulgated metals industry regulations, and quantitative and qualitative assessments
from engineering site visits and literature.
Based on the technologies listed in Tables 10-1 through 10-3, EPA identified the five
technology options used to develop the MP&M Phase I effluent guidelines. These
options consist of end-of-pipe treatment (Option 1), end-of-pipe treatment and in-process
source reduction and recycling (Option 2), tiered option for "low" flow and "high" flow
sites (Option 1A), end of pipe treatment and in-process source reduction and recycling
for "high" flow sites (Option 2A), and advanced end-of-pipe treatment and recycling
(Option 3). The technology trains for the options are presented in Figures 10-1 through
10-3 and discussed in the following paragraphs.
10.2.1 Option 1: End-of-Pipe Treatment
Chemical Precipitation and Sedimentation Treatment. Option 1 comprises the following
technologies:
• Chemical precipitation and sedimentation (including sludge
dewatering using gravity thickening, and pressure filtration).
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10.0 TECHNOLOGY OPTIONS
• Oil/water separation through chemical emulsion breaking and either
skimming or coalescing;
• Cyanide destruction through alkaline chlorination;
• Chemical reduction of hexavalent chromium;
• Chemical reduction of chelated metals; and
• Contract hauling of solvent degreasing wastewaters.
In Option 1, all process wastewaters are treated with end-of-pipe chemical precipitation
and sedimentation. Chemical precipitation and sedimentation involves adjusting the pH
of the wastewater with alkaline chemicals such as lime (calcium hydroxide) or caustic
(sodium hydroxide), or acidic chemicals (such as sulfuric acid) to produce insoluble metal
hydroxides. This step is followed by a settling process to remove the metal hydroxides.
This treatment train is widely used throughout the metals industry and is well
documented as being effective for removing pollutants present in MP&M wastewaters.
Some MP&M Phase I wastewaters require preliminary treatment prior to chemical
precipitation and sedimentation. These wastewaters contain pollutants such as oil and
grease, cyanide, hexavalent chromium, chelated metals, and organic solvents that can
inhibit the performance of chemical precipitation and sedimentation treatment. These
preliminary treatment technologies, which are described below, are most effective on
segregated wastewaters, prior to commingling with other wastewaters.
Oil-Bearing Wastewater. EPA has determined that some wastewaters, usually alkaline
cleaning wastewaters and water-based metal-working fluids (e.g., machining and grinding
coolants, deformation lubricants), may contain significant amounts of oil and grease.
These wastewaters require preliminary treatment to remove oil and grease and organic
pollutants. Chemical emulsion breaking followed by either skimming or coalescing
effectively removes these pollutants.
Cyanide-Bearing Wastewater. EPA has identified MP&M wastewaters that may contain
significant amounts of cyanide, such as plating and cleaning wastewaters. These
wastewaters require preliminary treatment to destroy the cyanide. This is typically
performed using alkaline chlorination with sodium hypochlorite or chlorine gas.
Hexavalent Chromium-Bearing Wastewater. EPA has identified hexavalent chromium-
bearing wastewaters, usually generated by acid treatment anodizing, conversion coating,
and electroplating operations and rinses. Because hexavalent chromium does not form a
hydroxide and is not treated by chemical precipitation and sedimentation, these
wastewaters require chemical reduction of the hexavalent chromium to trivalent
chromium. Trivalent chromium does form a hydroxide and is treated by chemical
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precipitation and sedimentation. Sodium metabisulfite or gaseous sulphur dioxide are
typically used as reducing agents.
Chelated Metal-Bearing Wastewaters. EPA has identified wastewaters that contain
significant amounts of chelated metals, such as electroless plating solutions and rinses.
These wastewaters require chemical reduction to break down the metal chelates prior to
chemical precipitation and sedimentation. Sodium borohydride, hydrazine, and sodium
hydrosulfite can be used as reducing agents.
Organic Solvent-Bearing Wastewaters. Option 1 also includes contract hauling of solvent
degreasing wastewaters. Based on data collected in DCPs and site visits, most solvent
degreasing operations use organic solvents (e.g., 1,1,1-trichloroethane, trichloroethene)
that are contract hauled for off-site recycling. Some MP&M Phase I sites reported the
use of organic solvent-water mixtures or rinses following organic solvent degreasing.
EPA considers contract hauling of these wastewaters as the most cost-effective disposal
method for these sites. It is important to note that solvent degreasing operations are
currently in a state of transition due to the phase-out of chlorinated solvents under the
Montreal Protocol.
10.2.2 Option 2: End-of-Pipe Treatment and In-Process Source Reduction and
Recycling
Option 2 comprises the technologies included in Option 1 plus in-process flow control
and pollution prevention technologies which allow for recovery and reuse of materials
along with water conservation. The specific Option 2 technologies include:
• The technologies included for Option 1;
• Flow reduction with flow restrictors, conductivity controllers or
timed rinses, and countercurrent cascade rinsing for all flowing
rinses;
• Flow reduction through manual control of the wastewater discharge
rate or through analytical testing and maintenance of bath chemistry
for all other process water-discharging operations;
• Centrifugation and 100 percent recycling of painting water curtains;
• Centrifugation and pasteurization to extend the life of water-soluble
machining coolants, reducing discharge volume by 80 percent; and
• In-process metals separation and recovery with ion exchange
followed by electrolytic recovery of the cation regenerants for
selected electroplating rinses. This includes first-stage drag-out
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rinsing (when necessary) with electrolytic metal recovery. These
technologies were not applied to chromium electroplating rinses
because chromium is not amenable to electrolytic recovery.
EPA has observed these pollution prevention and water conservation technologies at
MP&M Phase I sites during site visits and sampling episodes.
Technologies such as centrifugation and pasteurization for machining coolants,
centrifugation for painting water curtains, or ion exchange for electroplating rinses,
prolong the use of raw materials prior to disposal. In some instances, the technologies
recover metal or metal treatment solutions. Using these recovery technologies along
with flow reduction typically reduces the wastewater flow rate with a corresponding
increase in pollutant concentrations in the treatment influent streams.
Within the range of influent concentrations measured for the MP&M industry, the
effectiveness of chemical precipitation and sedimentation on metal-bearing wastewaters
is independent of influent concentration, since the performance of this technology is
limited by the solubility of metal hydroxides in water. For example, a well-operated
chemical precipitation and sedimentation treatment system achieves similar long-term
average concentrations for metal pollutants, whether the influent stream contains 10 or
100 mg/L of metal pollutants.
Sites reducing their wastewater flow rates and increasing their influent pollutant
concentrations will achieve more effective treatment, thereby reducing the mass of
pollutants discharged in the treated effluent. For example, if a site generates raw
wastewater at 2,600 gallons (10,000 liters) per day containing 10 mg/L of pollutant prior
to treatment, and implements water reduction and recovery technologies to reduce the
flow to 1,300 gallons (5,000 liters) per day while increasing the pollutant concentration to
20 mg/L prior to treatment, the site will reduce the mass of pollutants discharged by
treating to the same discharge concentration at half of the flow rate. If the long-term
average effluent concentration of a pollutant was 0.1 mg/L, the site would discharge
1,000 mg/day of pollutant (10,000 L/day times 0.1 mg/L) prior to implementing flow
reduction and recovery technologies, and 500 mg/day of pollutant (5,000 L/day times
0.1 mg/L) after implementation of the technologies. Option 2 is the preferred option for
direct dischargers.
10.2.3 Option 1A: Tiered Option for "Low" Flow and "High" Flow Sites
Option 1A is a tiered option, based on Options 1 and 2, depending on the annual
discharge volume at a given MP&M site. The Agency established this option for indirect
discharging sites only in development of Pretreatment Standards for Existing Sources
(PSES). For "low" flow sites, defined as sites with a discharge volume of less than
1,000,000 gallons per year (gpy), this option would require that sites comply with
concentration-based standards based on Option 1. For a site operating 250 days per
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10.0 TECHNOLOGY OPTIONS
year, 1,000,000 gallons per year translates into an average discharge flow rate of
4,000 gallons per day. For "high" flow sites, defined as sites with a discharge volume of
1,000,000 gpy or greater, this option would require that sites comply with mass-based
standards based on Option 2.
10.2.4 Option 2A: End of Pipe Treatment and In-Process Source Reduction and
Recycling for "High" Flow Sites (Preferred Option)
The Agency established this option for indirect discharging sites only in development of
pretreatment standards. Option 2 A requires that existing "high" flow indirect sites,
defined as sites with a discharge volume of 1,000,000 gallons per year or greater, comply
with mass-based standards based on Option 2. Existing "low" flow indirect sites would be
exempt from these standards. New indirect sites would be required to comply with mass-
based standards based on Option 2. Option 2A is the preferred option for indirect
discharging sites.
10.2.5 Option 3: Advanced End-of-Pipe Treatment and Recycling
Option 3 comprises the technologies included in Option 2 plus end-of-pipe ion exchange
with 90% reuse of the treated wastewater. This technology has been observed at MP&M
Phase I sites, and reported in DCPs. In this option, sites treat their wastewater for reuse
in the process, replacing a portion of the water supply used in the process area.
Option 3 technology is expected to sufficiently treat wastewater, such that 90% of the
treated wastewater can be reused in the process. The other 10% is discharged as a
bleed stream after treatment.
10.3 Technology Descriptions for In-Process Source Reduction and Recycling
Technologies
This section describes in detail in-process source reduction and recycling technologies
included in the MP&M technology options or considered by the Agency to be equivalent
or alternative to a technology included in the MP&M technology options. The
technology descriptions contain information on the application and performance of the
following technologies:
• Centrifugation and pasteurization of machining coolants;
• Centrifugation and recycling of painting water curtains;
• Countercurrent cascade rinsing;
• Electrodialysis;
• Electrolytic recovery;
• Flow reduction for rinses and baths;
• Ion exchange; and
• Reverse osmosis.
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10.3.1 Centrifugation and Pasteurization of Machining Coolants
Most machining coolants consist of water-soluble oil in water. The water-soluble coolant
is typically pumped through a coolant sump, over the machining tool and part during
machining, and returned to the sump. Coolant becomes spent for one or more of the
following reasons:
• The concentration of suspended solids in the coolant begins to
inhibit performance;
• Nonemulsified, or "tramp", oil collects on the surface of the coolant;
• The coolant becomes rancid due to microbial growth; or
• Coolant additives are consumed reducing corrosion prevention and
lubrication properties.
Centrifugation and pasteurization can be used along with oil skimming and biocide
addition to reduce coolant discharge and pollutant generation at the source. Buildup of
suspended solids in the machining coolant is removed using the centrifuge. Tramp oil
can also be removed if the centrifuge used is capable of liquid-liquid separation. If the
centrifuge used is only capable of liquid-solid separation, an oil skimmer can be used for
removal of tramp oil. Microbial growth is controlled through pasteurization but can also
be controlled by adding biocides. Using these technologies can extend the usable life of
a water-soluble coolant considerably and, in many cases, indefinitely. A flow diagram of
a typically machining coolant Centrifugation and recycling system is shown in Figure 10-4.
These technologies result in sites reducing the amount of coolant and wastewater
requiring treatment and disposal, and reducing the amount of fresh coolant purchased.
The coolant recycling technologies are most effective when sites consolidate the types of
coolants used, and use a centralized coolant recycling system. However, some sites may
not be able to consolidate the types of coolants used, because of product or customer
specifications. In this case, sites may need to purchase dedicated coolant recycling
systems for each type of coolant used.
The centrifuge is a simple unit that is very reliable and requires only routine
maintenance, such as periodic cleaning and removal of accumulated solids. Flow rate is
the only operating factor to control. The sludge generated from this technology is
commonly classified as a hazardous waste. This determination is based on the metal
type processed, and the amount of metal that dissolves into the coolant. The sludge is
typically contract hauled for treatment and disposal.
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10.3.2 Centrifugation and Recycling of Painting Water Curtains
Water curtains are used to catch paint overspray in spray painting booths. This water is
continuously recirculated until the solids content in the wastewater necessitates either in-
process treatment and recycling or discharge. Sites may employ in-process filters (e.g.,
cloth filters) for solids removal. Centrifugation of spent water curtains is used to remove
the solids and recycle the water curtain, eliminating the need for discharge.
Centrifugation is a physical removal process to remove solids from paint curtain
wastewater. In this system, wastewater is pumped to a holding tank, then through the
centrifuge. Solids are contract hauled for off-site disposal, while the treated wastewater
is returned to the paint booth. Chemical addition may be necessary prior to
Centrifugation to achieve effective solids removal. A flow diagram of a typical paint
curtain Centrifugation and recycling system is shown in Figure 10-5.
In the Centrifugation process, a holding tank large enough to hold the entire volume of
the water curtain is necessary. The wastewater is pumped from the water curtain
through the centrifuge, where the rotation of the centrifuge forces the solids to be caught
in the bowl of the centrifuge, while the treated wastewater is discharged out the center
and returned to the sump.
During operation of the paint curtain, solids will accumulate on the bottom of the water
curtain sump. Centrifugation of the paint curtain should proceed until all wastewater is
treated and the sludge remains in the sump. The sludge in the water curtain sump must
be removed either manually, with a sludge pump, or by a vacuum truck. After the
sludge has been removed and the water curtain has been treated through the centrifuge,
the wastewater from the holding tank is pumped back into the water curtain sump.
Make-up water is added to compensate for evaporation. Using this procedure, the paint
curtain water can be continuously recycled.
Wastewater from painting water curtains commonly contains organic pollutants as well as
certain metals. Eliminating the discharge of wastewater from painting water curtains
may eliminate the need for an end-of-pipe treatment step for organic pollutants at
certain sites. Also, if a site only generates painting wastewater, additional wastewater
treatment would not be necessary if the paint curtain water was continuously recycled.
The centrifuge is a simple unit that is very reliable and requires only routine
maintenance. Flow rate is the only operating factor to control. One disadvantage of this
technology is that it may not be economically feasible for sites generating only a small
amount of paint curtain wastewater. In cases where sites have multiple sumps, portable
centrifuges can be used.
The sludge generated from painting water curtains, is commonly classified as a hazardous
waste, based on the type of paint used, and is typically contract hauled for treatment and
disposal. Most sites employing painting water curtains currently generate sludge from in-
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process solids filtration and sump cleanout. The Agency anticipates that additional
sludge will be generated by centrifugation and recycling of the water curtains.
10.3.3 Countercurrent Cascade Rinsing
Rinsing follows many MP&M unit operations to dilute and remove dirt, oil, or chemicals
remaining on parts and racks from a previous unit operation. By removing drag-out
from the surface of the part, rinsing improves the quality of the surface finishing process
and prevents the contamination of subsequent process baths. The quantity of water
required for good rinsing depends on the number of rinse tanks and their configuration.
Single rinse tanks with a continuous overflow are an inefficient use of water. A common
method of improving water use efficiency is to install a multiple rinse tank arrangement,
such as countercurrent cascade rinsing.
Countercurrent cascade rinsing is widely used for reducing the discharge rate of rinse
water at MP&M Phase I sites. A diagram showing the application of countercurrent
cascade rinsing is presented in Figure 10-6. Fresh water flows into the rinse tank located
farthest from the process tank and overflows, in turn, to the rinse tanks closer to the
process tank. This technique is termed countercurrent rinsing, because the work piece
and the rinse water move in opposite directions. Over time, the first rinse becomes
contaminated with drag-out and reaches a stable concentration which is lower than the
process solution. The second rinse stabilizes at a lower concentration, which enables less
rinse water to be used than if only one rinse tank were in place. The more
countercurrent cascade rinse tanks (three-stage, four-stage, etc.), the less water needed to
adequately remove the process solution.
The rinse rate needed to adequately dilute drag-out depends on the concentration of
process chemicals in the drag-out, the concentration of plating chemicals that can be
tolerated in the final rinse tank before poor plating results, and the number of
countercurrent cascade rinse tanks. These factors are expressed in the following
equation(2):
l/n
c
V =
cf
x V (1(M)
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10.0 TECHNOLOGY OPTIONS
where:
Vr = the flow through each rinse stage, gal/min;
C0 = the concentration of the contaminant(s) in the initial process
bath, mg/L;
Cf = the tolerable concentration of the contaminant(s) in the final
rinse to give acceptable product cleanliness, mg/L;
n = the number of rinse stages used; and
VD = the drag-out carried into each rinse stage, expressed as a
flow, gal/min.
This mathematical rinsing model is based on complete rinsing (i.e., removal of all drag-
out from the part/fixture) and complete mixing (i.e., homogeneous rinse water). Under
these conditions, each additional rinse stage can reduce rinse water use by 90 percent.
These conditions are not achieved unless there is sufficient residence time and agitation
in the rinse tank. For less efficient rinse systems, each added rinse stage reduces rinse
water use by 50 to 75 percent.
Countercurrent cascade rinsing systems have the following limitations: cost of additional
rinse tanks; loss of production space; and an increase in production time and labor.
Also, when countercurrent cascade rinsing is used, the low flow rate through the rinse
tanks may not provide the needed agitation for drag-out removal. In such cases, air or
mechanical agitation is added to increase rinsing efficiency.
10.3.4 Electrolytic Recovery
Electrolytic recovery is an electrochemical process used to recover metals from many
types of process solutions, such as electroplating rinse waters and baths. Electrolytic
recovery removes metal ions from a waste stream by processing the stream in an
electrolytic cell, which consists of a closely spaced anode and cathode. Commercial
equipment is comprised of several cells, a transfer pump, and a rectifier. Current is
applied across the cell and metal cations are deposited on the cathodes. The waste
stream is usually recirculated through the cell from a separate tank, such as a drag-out
recovery rinse. Figure 10-7 presents a diagram of a typical electrolytic recovery system.
The capacity of electrolytic recovery equipment depends on the total cathode area and
the maximum rated output of the rectifier. Commercial units are available with a
cathode area ranging from 1 to 100 ft2 and more, and an output of 10 to 1,000 amperes
or more. Theoretical electrolytic recovery rates are determined by Faraday's law and
range from 1.19 grams/amp-hour for divalent copper to 7.35 grams/amp-hour for
monovalent gold. Actual rates are usually much lower and depend on the metal
concentration in the waste stream. At low concentrations (under 100 mg/L), electrolytic
recovery rates may be below 10% of the theoretical maximum.
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Various types of cathodes are used in electrolytic recovery units, depending mainly on
the concentration of metal in the waste stream. The different cathodes are often
classified by their surface area. Flat-plate cathodes have the lowest surface area and are
used only for recovering gross quantities of metal from metal-rich waste streams (usually
1 to 20 g/L of metal). Reticulate cathodes, which have a metallized woven fiber design,
have a surface area ten times greater than their apparent area. These cathodes can be
used over a wide range of metal concentrations but, due to cost factors (reticulate
cathodes are disposable), are typically used where the dissolved metal concentration is
below 1 g/L. Carbon and graphite cathodes have the highest surface area per unit of
apparent area. Their use is usually restricted to metal concentrations below 100 mg/L.
Electrolytic recovery is applied to solutions containing nickel, copper, precious metals,
and cadmium. Chromium and aluminum are poor candidates for electrolytic recovery.
Drag-out recovery rinses and ion-exchange regenerant are common sources of solutions
that are processed using electrolytic recovery. Some solutions require pH adjustment
prior to electrolytic recovery. Acidic, metal-rich, cation regenerant is an excellent
candidate stream for electrolytic recovery, and is often electrolytically recovered without
adjustment. In some cases, when the target concentration is reached, the waste stream is
reused as cation regenerant.
Dissolved metals in electrolytes can be recovered to low levels (< 5 mg/L) using
reticulate or carbon cathodes. In practice, however, the target concentration for most
applications is 50 to 250 mg/L or higher. With flat-plate cathodes, the target
concentration is usually above 0.5 g/L, because plating efficiency drops as concentration
falls. Plating time required to lower the concentration of a pollutant from 100 to
10 mg/L can be several times longer than that required to lower the concentration from
10,000 mg/L to 100 mg/L. Also, unit energy costs (measured in dollars per pound of
metal recovered) increase substantially at lower metal concentrations.
Electrolytic recovery is offered by numerous vendors, and is applicable to a wide range
of rinse solutions and ion-exchange regenerants due to the number of materials and
configurations available for anodes and cathodes. All of the commonly electroplated
metals, except chromium, can be recovered using electrolytic recovery.
Electrolytic recovery is not applicable to flowing rinses due to the lower metal
concentrations and the extended time required for metal recovery. In most cases,
electrolytic recovery cannot cost effectively remove dissolved metals to concentrations
required for discharge. Electrolytic recovery is used more for gross metal recovery
rather than as a compliance technology.
Labor requirements are relatively low for electrolytic recovery. Units recovering metal
from drag-out recovery tanks may only require occasional cleaning and maintenance.
Units treating batch discharges from ion-exchange units require more labor due to the
higher metal content of that solution and the resultant increase in cathode loading
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frequency. Energy costs for this technology can be significant, and, in some cases, exceed
the recovery value of the metal. Energy requirements depend on several factors,
including required voltage, rectifier efficiency, and current efficiency. More concentrated
solutions will generally be recovered in a more energy-efficient manner than dilute
solutions. Electrode replacement costs may be significant for units using disposable
cathodes, especially when high metal recovery rates are encountered. If the materials of
construction are properly selected for a given electrolyte, permanent cathodes and
anodes may last more than five years for most applications.
10.3.5 Flow Reduction for Rinses and Baths
Flow reduction for rinses and baths encompasses a set of technologies that can be
applied to MP&M rinses and process baths to reduce the wastewater discharge rate.
These technologies involve water use reduction and bath maintenance and regeneration.
The potential for reducing water use at MP&M sites is evident in the water use and
discharge data in the DCP database. These data show large variations in site water use
per unit of production. While some variations in water flow per unit of production result
from process conditions, on-site observations during site visits indicated that most
variations are caused by water use practices, including imprecise control of water use.
Rinse Water Reduction
For a given rinse tank design and configuration, there is a minimal rinse water flow rate
that provides adequate rinsing. This minimum flow rate can be achieved by coordinating
the amounts of rinse water and drag-out. There are various means to control flow, the
selection of which depends on the nature of the production operations and the
preference of the MP&M site. Three common flow control methods include flow
restrictors, timers, and conductivity rinse controls. These technologies have been
observed at many MP&M Phase I sites.
Flow Restrictors. Flow restrictors are commonly installed on a rinse tank's water inlet.
These devices contain an elastomer washer which flexes under pressure to maintain a
constant water flow regardless of pressure. Flow restrictors can maintain a wide range of
flow rates, from less than 0.1 gal/min to more than 10 gal/min.
As a stand-alone device, a flow restrictor provides a constant water flow. As such, for
intermittent rinsing operations, a flow restrictor does not coordinate the rinse flow with
drag-out introduction. Precise control with intermittent operations typically requires a
combination of flow restrictors and rinse timers. However, for continuous rinsing (e.g.,
continuous electroplating machines), flow restrictors may be adequate for good water
control.
Rinse Timers. Rinse timers are electronic devices that control a solenoid valve. The
timer usually consists of a button that, when pressed, opens the valve for a
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predetermined length of time, usually from 1 to 99 minutes. After the time period has
expired, the valve is automatically shut. The timer may be activated either manually by
the operator or automatically by the action of racks or hoists.
Most rinse systems that are used intermittently benefit from the installation of a rinse
timer, as operator error is eliminated. Rinse timers installed in conjunction with flow
restrictors can provide precise control when the incoming water pressure may rise and
fall. Rinse timers are less effective in continuous or nearly continuous rinse operations
(e.g., continuous electroplating machines).
Conductivity Controllers. Conductivity controllers consist of a controller, a meter with
adjustable set points, a probe that is placed in the rinse tank, and a solenoid valve. As
parts are rinsed, dissolved solids are added to the water in the rinse tank, raising the
conductivity of the water. When conductivity reaches a predetermined set point, the
solenoid valve is opened. When the conductivity falls below the set point, the valve is
shut.
In theory, conductivity control of rinse flow is a precise method of maintaining optimum
rinsing conditions in intermittently used rinse operations. In reality, conductivity
controllers work best with deionized rinse water. Incoming water conductivity may vary
day-to-day and season-to-season, which forces frequent setpoint adjustments. Suspended
solids and nonionic contaminants (e.g., oil) are not detected by the conductivity probe
and can cause inadequate rinsing.
Bath Maintenance and Regeneration
Process baths become contaminated with impurities that affect their performance. The
sources of contamination include: (1) breakdown of process chemicals; (2) buildup of
byproducts (e.g., carbonates); (3) contamination from impurities in make-up water,
chemicals, or anodes; (4) corrosion of parts, racks, tanks, heating coils, etc.; (5) drag-in
of chemicals; (6) errors in bath additions; and (7) airborne particles entering the tank. If
left untreated, process baths eventually become unusable and require disposal. MP&M
sites commonly use bath maintenance techniques to extend the useful lives of process
solutions and reduce waste generation. Several of the more common techniques include
filtration, carbon treatment, electrolysis, carbonate freezing, and chemical precipitation.
These methods are discussed below.
There are many production, environmental, and cost advantages to maintaining process
baths. When used on a continuous or routine basis, these practices maintain the baths in
good operating condition and result in consistent production results. They also lower the
total dissolved solids concentration of the bath, which reduces the drag-out rate. Use of
these technologies reduces the pollutant loading to the wastewater treatment system
resulting in a reduction of wastewater treatment chemical purchases and sludge disposal
costs.
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Filtration. Filtration is used to remove suspended solids from surface finishing solutions.
Suspended solids in surface finishing solutions may cause roughness and burning of
deposits. Filtration uses various types of equipment; the most common of which are
cartridge filters, precoat diatomaceous earth filters, and sand or multimedia filters.
Cartridge filters are available with either in-tank or external configurations. The in-tank
units are used mostly for small tanks and the external units for larger tanks. Most
cartridges are disposable; however, washable and reusable filters are available, which
further reduce waste generation. Precoat, sand, and multimedia filters are used mostly
for large tanks. Filter media are selected based on the chemical composition of the
bath. All filtration systems are sized based on solids loading and the required flow rate.
Typical flow rates for electroplating solution applications are 2 to 3 bath volumes per
hour.
Carbon Treatment. Carbon treatment of electroplating baths is a common method of
removing organic contaminants. The carbon adsorbs organic impurities that result from
the presence of oil or the breakdown of bath constituents, such as wetting agents. It is
used on both a continuous and batch basis, depending on the site's preference. Various
application methods are available, including carbon filtration cartridges (restricted to use
on small applications), carbon canisters (used mostly for moderately sized applications),
and precoat filters and bulk application/agitation/filtration (used mostly for larger
applications). Carbon treatment is most commonly applied to nickel, copper, zinc, and
cadmium electroplating.
Electrolysis. Electrolysis (also referred to as dummy plating) is a bath maintenance
process in which metallic contaminants (tramp metals) in a surface finishing solution are
either plated out (low-current density electrolysis) or oxidized (high-current density
electrolysis). Low-current density (LCD) electrolysis is applied to a range of plating and
other surface finishing processes, including nickel, copper, and zinc electroplating baths.
The tramp metals that are most frequently removed by electrolysis are copper, zinc, iron,
and lead. With LCD electrolysis, the tramp metals are selectively plated out onto a
corrugated steel sheet cathode by applying a current density that avoids plating the
primary metal constituent in the bath. The normal range is 2 to 8 amperes per square
foot (ASF). The duration of treatment is typically 2 to 5 amp-hr/gal. In high current
density (HCD) electrolysis, trivalent chromium is oxidized to hexavalent chromium in
chromic acid baths (e.g., chromium electroplating and chromic acid anodizing). Lead or
lead alloy anodes are typically used in the process. A lead peroxide film is formed on
the anode which functions as the oxidation agent. Current densities of 100 to 300 ASF
are used.
Carbonate Freezing. Carbonate freezing is a method of removing excessive carbonate
buildup by forming carbonate salt crystals at a low temperature. This process is most
often applied to electroplating baths formulated with sodium cyanide. Carbonates are
formed by the breakdown of cyanide (especially at high temperatures), excessive anode
current densities, and the adsorption of carbon dioxide from the air. An excessive
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carbonate concentration reduces the quality of the product. Carbonate freezing takes
advantage of the low solubility of carbonate salts in the sodium cyanide bath. The
method involves lowering the bath temperature to approximately 26 °F (-3°C) at which
point hydrated salt (Na2CO3-10H2O) crystallizes out of solution.
Chemical Precipitation. Chemical precipitation is a batch process in which certain
inorganic contaminants are removed from electroplating baths. Precipitation is an
alternative method to carbonate freezing for cyanide baths and is especially applicable to
potassium cyanide baths. Chemicals used for this purpose include barium cyanide,
barium hydroxide, calcium hydroxide, or calcium sulfate. The least expensive of these
chemicals, calcium sulfate, forms a bulky precipitate that is more difficult to remove.
Other common uses of precipitation include sodium sulfide treatment of cyanide baths
for zinc and lead removal, nickel carbonate or nickel hydrate treatment of nickel plating
baths to remove miscellaneous metal contaminants (e.g., iron, aluminum, silicon), and
potassium permanganate treatment of zinc baths to remove iron. Frequently, the process
is performed in a spare tank where the solution is chemically treated, filtered, and
returned to service.
10.3.6 Ion Exchange (in-process)
Ion exchange is a reversible chemical reaction which exchanges ions in a feed stream for
ions of like charge on the surface of an ion-exchange resin. Resins are broadly divided
into cationic or anionic types. Typical cation resins exchange H+ for other cations, while
anion resins exchange OH" for other anions. Figure 10-8 presents a typical ion-exchange
column configuration.
In practice, a feed stream is passed through a vessel, referred to as a column, which
holds the resin. The feed stream is usually either dilute rinse water (in-process ion-
exchange) or treated wastewater (end-of-pipe ion exchange). Often, prior to ion-
exchange treatment, the feed stream passes through a cartridge filter and a carbon filter
to remove suspended solids and organics that foul the resin bed. The exchange process
proceeds until the capacity of the resin is reached (i.e., an exchange has occurred at all
the resin sites). A regenerant solution is then passed through the column. For cation
resins, the regenerant is an acid, and the H+ ions replace the cations captured from the
feed stream. For anion resins, the regenerant is a base, and OH" ions replace the anions
captured from the feed stream. The concentration of feed stream ions is much higher in
the regenerant than in the feed stream; therefore, the ion-exchange process accomplishes
both separation and concentration.
Ion exchange is used for water recycling and/or metal recovery. For water recycling,
cation and anion columns are placed in series. The feed stream is deionized and the
product water is reused for rinsing. Often, closed-loop rinsing is achieved. The
regenerant from the cation column typically contains the metal species, which can be
recovered in elemental form via recovery. The anion regenerant is typically discharged
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to wastewater treatment. When metal recovery is the only objective, a single or double
cation column unit containing selective resin is used. These resins attract divalent
cations while allowing monovalent cations to pass, a process usually referred to as metal
scavenging. Water cannot be recycled because contaminants other than the target
cations remain in the stream exiting the column.
Ion-exchange equipment ranges from small, manual, single-column units to multicolumn,
highly automated units. For continuous service, two sets of columns are necessary. One
set handles the service flow, and the other set is regenerated. Thus, two-column metal
scavenging and four-column deionizing systems are common. Automatic systems direct
the wastewater flow and initiate regeneration with little or no operator interaction.
Equipment size is based on flow volume and concentration. Resin capacity varies but
often ranges from 1 to 2 lbs/ft3. Flow rates may range from 1 to 20 or more gpm.
Columns are typically sized to handle wastewater flow for at least a period of time equal
to the time required for regeneration. Automatic systems are sized to provide
continuous service. Regeneration volume typically ranges from 2 to 4 resin bed volumes
of dilute acid or caustic. Concentrations of feed stream contaminants generally range
from 10 to 20 g/L.
The labor requirements for ion exchange depend on the automation level of the
equipment. Manual systems can incur significant labor costs associated with preparing,
transporting, and disposing of regenerants. Automatic systems require far less labor.
Resins, usually lasting for years, eventually need to be replaced due to organic
contamination, resin oxidation, and fouling from suspended solids. This process can be
hastened by misuse, accidents, or poor engineering. Resin replacement costs can be
10 to 20% of the original capital investment.
Ion exchange is applied in two basic configurations (see Figure 10-8): water recycling
and/or metal scavenging (recovery). Deionizing removes all cations and anions from a
relatively dilute rinse stream and recycles the deionized water back to the rinsing
process. Generally, the total dissolved solids concentration of such streams must be
below 500 mg/L, to maintain an efficient regeneration frequency. In some cases, the
cation or anion regenerant is compatible with the bath chemistry and can be directly
reused in the bath. Usually, however, the regenerant is too dilute or incompatible with
the process chemistry and it cannot be reused. In these cases, the metal ions in the
regenerant can be recovered using electrolytic recovery or waste treatment. Drag-out
reduction, including drag-out tanks, can enhance the efficiency of the recovery process.
Effluent total dissolved solids levels of 2 mg/L or less are typical.
Metal scavenging recovers only the metal content of the drag-out. This technology is
efficient if the metal ions being scavenged are the primary source of ions in the stream.
The metal content of the stream may only be a small fraction of the total dissolved solids
(TDS) present in the stream, making scavenging suitable over a wider range of TDS.
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Scavenging also provides a highly concentrated regenerant, particularly suitable for
electrolytic recovery. Water recycling is not possible since only some of the cations and
none of the anions are removed. Effluent metal concentrations of under 0.5 mg/L are
typically achieved with standard installations. Scavenging resin systems can also be used
to polish discharge from a conventional wastewater treatment system. Ions are
selectively captured by the resin, but concentrated salts used for pH neutralization pass
through. The regenerant may be sent to an electrolytic recovery device to recover metal,
or returned upstream to the conventional wastewater treatment system.
Many process wastewaters are excellent candidates for ion exchange, including the rinse
water from plating processes of copper, cadmium, gold, lead, nickel, tin, tin-lead, and
zinc. Gold-bearing resins are difficult to regenerate, and frequently require incineration
to recover the gold content. Lead is also difficult to recover from ion exchange resins.
Methane sulfonic acid (very expensive) and fluoboric acid (usually not suitable for
electrolytic recovery) are effective regenerants; these resins may be replaced when
exhausted rather than regenerated. Cyanide rinse waters are amenable to ion exchange;
cation resins are capable of breaking the metal-cyanide complex and the cyanide is
removed in the anion column. The cation regenerant can be electrolytically recovered
and the cyanide present in the anion regenerant can be returned to the process or
discharged to treatment.
Ion exchange is a commonly used technology within the MP&M industry. In addition to
water recycle and chemical recovery applications, ion exchange is used to soften or
deionize raw water for process solutions.
10.3.7 Reverse Osmosis (both in-process and end-of-pipe)
Reverse osmosis is a membrane separation technology used by the MP&M industry for
chemical recovery. The feed stream, usually relatively dilute rinse water or wastewater,
is pumped to the surface of the reverse osmosis membrane at pressures of 400 to
1,000 psig. The membrane separates the feed stream into a reject stream and a
permeate. The reject stream, containing most of the dissolved solids in the feed stream,
is deflected from the membrane while the permeate passes through. Reverse osmosis
membranes reject more than 99% of multivalent ions and 90 to 96% of monovalent ions,
in addition to organics and nonionic dissolved solids. The permeate stream is usually of
sufficient quality to be recycled as rinse water, despite the small percentage of
monovalent ions (commonly potassium, sodium and chloride) that pass through the
membrane.
A sufficiently concentrated reject stream can be returned directly to the process bath.
The reject stream concentration can be increased if the stream is recycled through the
unit more than once or by increasing the feed pressure. In multiple-stage units
containing more than one membrane chamber, the reject stream from the first chamber
is routed to the second, and so on. The combined reject streams from multistage units
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may, in some cases, have high enough concentrations to be returned directly to the bath.
A flow diagram of a common configuration for a reverse osmosis recovery system is
shown in Figure 10-9.
The capacity of reverse osmosis equipment is generally measured in flow volume, and is
determined by the membrane surface area and operating pressure. Generally, capacity is
increased by increasing the surface area of the membrane. Operating at higher pressures
will increase the permeate flow volume per unit membrane area (also called the flux).
Reject stream concentration increases with pressure and decreases as flow volume
increases.
Prefiltering and pretreating the feed stream may be necessary to lengthen membrane life
or reduce the frequency of fouling. Filtration to remove suspended solids is usually
necessary. Adjustment of pH may prevent precipitation from occurring as the feed
stream is concentrated, but it may make the concentrate unfit to return to the process
bath.
Reverse osmosis is most applicable to electroplating rinse waters, including Watts nickel,
bright nickel, brass cyanide, copper cyanide, and zinc cyanide. Total dissolved solids
(TDS) concentrations of 1,000 mg/L or more can be tolerated. Permeate TDS
concentrations of 250 mg/L or less are typical, and the dissolved solids are mostly
common monovalent ions, allowing the permeate stream to be reused in most rinsing
operations.
The reject stream concentration limit for basic reverse osmosis equipment is
approximately 20 g/L TDS. Multipass and multistage units achieve higher
concentrations, approaching 30 g/L TDS or higher. If the reject stream is acceptable to
return directly to the process bath and the permeate is recycled as rinse water, a closed
loop is created. However, returning the reject stream directly to the bath is, in practice,
uncommon, because the concentration is too low. Reject streams can be electrolytically
recovered, treated conventionally, or reconcentrated by evaporation and returned to the
process.
During the operation of reverse osmosis, energy is consumed only by pumps. In most
cases, water recycling is achieved; in some cases, a closed loop is possible. Compared to
ion exchange, reverse osmosis has the advantage of tolerating somewhat higher feed
stream concentrations. The concentration of reverse osmosis reject streams are near or
higher than that of ion exchange regenerants. Both are less effective in handling
oxidizing chemistries or feed streams high in organics and total suspended solids (TSS).
Ion exchange effluent generally has a lower TDS concentration than reverse osmosis
permeate and is appropriate to recycle in all rinses. For most applications, membrane
life is measured in years, although membranes are susceptible to fouling from organics,
suspended solids, or misuse. Reverse osmosis units may have instrumentation that
indicates the condition of the membrane by measuring the flux. If the membrane fouls
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or clogs, the flux rate drops, and the membrane should be cleaned. Pressure and other
flow gauges are common.
In cases where the reject stream concentration is not high enough to warrant return to
the bath, the reject stream can be concentrated with an evaporator, electrolytically
recovered, or treated conventionally. When used with evaporators, reverse osmosis loses
its low-energy advantage over other in-process reuse and recovery technologies. When
both technologies are configured with an electrolytic recovery unit, reverse osmosis often
has a higher capital cost than ion exchange. As an end-of-pipe treatment, reverse
osmosis and ion exchange are competitive in terms of metals removal; reverse osmosis
may result in greater opportunity for water recycling.
Labor needs to operate reverse osmosis equipment are associated with periodic
membrane cleaning. Membrane and pump replacement are the primary maintenance
items. Membranes generally last 1 to 5 years, depending on the application, but misuse,
or changes in feed stream characterization, can have a significant negative impact.
10.4 Technology Descriptions for Preliminary Treatment of Segregated
Wastewater Streams
This section describes in detail technologies used for the preliminary treatment of
segregated wastewater streams and included in the MP&M technology options.
Technology descriptions contain information on the application and performance of the
following technologies:
• Chemical reduction of chelated metals;
• Chemical reduction of hexavalent chromium;
• Cyanide destruction through alkaline chlorination; and
• Oil/water separation.
10.4.1 Chemical Reduction of Chelated Metals
Certain MP&M wastewaters contain chelating agents which interfere with conventional
chemical precipitation processes. These wastewaters are often associated with electroless
plating, and require specific treatment for the chelated metals. In general, there are
three methods of treating these wastewaters:
• Reduction to elemental metal;
• Precipitation as an insoluble compound; and
• Physical separation.
Reduction to elemental metal involves the use of either electrical current or reducing
agents to reduce the metal ion to its elemental form (i.e., Ni2+ to Ni°). The metal is
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recovered either in the form of a metal film on a sacrificial anode or as a metal
precipitate.
Precipitation as an insoluble compound involves either precipitation methods that are
not affected by chelation, or methods that involve breaking the chelate prior to
traditional forms of precipitation.
Separation of bath constituents is performed by membrane filtration or ion exchange.
These technologies usually generate both a dilute and a concentrated waste stream, both
of which may be reused or hauled off-site for treatment and disposal.
Reduction to Elemental Metal
Reduction to elemental metal can be performed using one of two methods. One method
is electrolytic recovery in which the dissolved metal is deposited on the cathode for
reclamation or disposal. The electric current provides the electrons to reduce the metal
ion to its elemental form. The reaction rate, and achievable concentration for this
technology, are dependent on the volume of wastewater per unit surface area of cathode.
This method typically does not achieve metals concentrations sufficiently low enough for
wastewater discharge.
The second method uses a reducing agent to provide the electrons to reduce the metal.
Possible reducing agents for use in chelated wastewater streams include:
• Sodium borohydride.
• Hydrazine.
• Sodium hydrosulfite.
Upon reduction, the metal forms a particulate in solution which can then be removed by
conventional solids removal techniques. These reducing agents sometimes require the
use of other chemicals for pH adjustment, to be used effectively. Figure 10-10 presents a
process diagram for this method of chemical reduction of chelated metals.
Precipitation as an Insoluble Compound
The presence of chelating agents hinders the formation of hydroxides, making hydroxide
precipitation ineffective on chelated wastewaters. Some other precipitation methods that
are not affected or less affected by the presence of chelating agents include: sulfide
precipitation, dithiocarbamate (DTC) precipitation, and carbonate precipitation. With
the exception of DTC precipitation, all of these technologies are discussed under the
chemical precipitation portion of this section. DTC is added to solution in stoichiometric
ratio to the metals present. DTC is effective in treating chelated wastewater; however,
DTC is also used as a pesticide and, if used incorrectly, may cause process upsets in the
biological treatment used at a POTW. The use of DTC by direct dischargers can be
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especially harmful to the aquatic environment because the direct dischargers' wastewater
does not go through the biological treatment at a POTW. DTC precipitation generates
large amounts of sludge, but is effective in treating electroless plating wastewaters.
Physical Separation
Metals can be separated from solution by ion exchange and reverse osmosis. These
technologies are not affected by chelators in the wastewater, making these techniques
effective in treating wastewater from electroless plating. These technologies are
discussed in this section separately.
10.4.2 Chemical Reduction of Hexavalent Chromium
Reduction is a chemical reaction in which electrons are transferred from one chemical
(the reducing agent) to the chemical being reduced. Sulfur dioxide, sodium bisulfite,
sodium metabisulfite, and ferrous sulfate form strong reducing agents in water. They are
often used at MP&M sites to reduce hexavalent chromium to the trivalent form, which
allows the metal to be removed from solution by chemical precipitation. Chromium
reduction is necessary because hexavalent chromium does not form a hydroxide, and
therefore is not precipitated by hydroxide precipitation.
Sodium metabisulfite, sodium bisulfite, and sulfur dioxide are the most widely used
reducing agents at MP&M sites. The reaction in these processes is illustrated for the
following sulfur dioxide reaction (reduction using other reagents is chemically similar):
2H2CrO4 + 3S02 -* Cr2(SO4)3 + 2H2O (10-2)
An operating pH of between 2 and 3 is normal. At pH levels above 5, the reduction
rate is slow and oxidizing agents such as dissolved oxygen and ferric iron interfere with
the reduction process by consuming the reducing agent.
A typical treatment involves retention in a reaction tank for 45 minutes. The reaction
tank is equipped with pH and oxidation-reduction potential (ORP) controls. Sulfuric
acid is added to maintain a pH of approximately 2.0, and a reducing agent is metered to
the reaction tank to maintain the ORP at 250 to 300 millivolts. The reaction tank is
equipped with an impeller designed to provide approximately one bath volume per
minute. Figure 10-11 presents a process flow diagram of a continuous chromium
reduction system.
Chemical reduction of hexavalent chromium is a proven technology that is widely used at
MP&M sites. Operation at ambient conditions requires little energy, and the process is
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well suited to automatic control. A limitation to this technology is that, for high
concentrations of chromium, treatment chemicals may be prohibitively expensive.
Maintenance of chemical reduction systems consists of sludge removal, the frequency of
which is a function of the input concentrations of detrimental constituents. There may
be small amounts of sludge collected due to minor shifts in the solubility of the
contaminants (e.g., iron hydroxides). This sludge can be processed by the sludge-
handling equipment associated with the chemical precipitation system.
10.4.3 Cyanide Destruction through Alkaline Chlorination
Cyanide destruction through alkaline chlorination is widely used in industrial wastewater
treatment. Chlorine is typically used as either chlorine gas or sodium hypochlorite. This
process can be illustrated by the following two-step chemical reaction:
C12 + NaCN + 2NaOH -» NaCNO + 2NaCl + H2O (10-3)
3C12 + 4NaOH + 2NaCNO -> 2CO2 + N2 + 6NaCl + 2H2O (10-4)
Figure 10-12 presents a process flow diagram for the alkaline chlorination of cyanide.
The alkaline chlorination process oxidizes cyanides to carbon dioxide and nitrogen. The
equipment often consists of an equalization tank followed by two reaction ranks,
although a batch reaction can be conducted in a single tank. Each tank has an electronic
controller to monitor and maintain the required pH and ORP. In the first reaction tank,
conditions are adjusted to oxidize cyanides to cyanates. To effect the reaction, chlorine
or sodium hypochlorite is metered to the reaction tank as necessary to maintain the ORP
at 350 to 400 millivolts, and aqueous sodium hydroxide is added to maintain a pH of 10
to 11. In the second reaction tank, the ORP and the pH level are maintained at
600 millivolts and 8 to 9, respectively, to oxidize cyanate to carbon dioxide and nitrogen.
Each reaction tank has a chemical mixer designed to provide approximately one turnover
per minute. The batch process is usually accomplished by using two tanks, one to collect
water over a specified time period and one to treat an accumulated batch. If
concentrated wastes are frequently dumped, another tank may be required to equalize
the flow to the treatment tank. When the holding tank is full, the liquid is transferred to
the reaction tank for treatment.
Alkaline chlorination can be performed at ambient temperature, can be automatically
controlled at relatively low cost, and is capable of achieving effluent levels of free
cyanide that are nondetectable. Disadvantages include the need for careful pH control,
possible chemical interference in treating mixed wastes, and the potential hazard of
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storing and handling chlorine gas (if sodium hypochlorite is not used). If organic
compounds are present, toxic chlorinated organics may be generated. Alkaline
chlorination is not effective in treating metallocyanide complexes, such as ferrocyanide.
Alkaline chlorination is reliable with proper monitoring and control and proper
pretreatment to control interfering substances.
10.4.4 Oil/Water Separation
Oil/water separation includes the breaking of oil/water emulsions as well as the gravity
separation of oil. When only free oil is present, only oil skimming is necessary for
effective treatment. These technologies are discussed below.
Chemical Emulsion Breaking
Chemical emulsion breaking is used to break stable oil/water emulsions (oil dispersed in
water, stabilized by electrical charges and emulsifying agents). A stable emulsion will
not separate or break down without chemical treatment. Chemical emulsion breaking is
applicable to wastewater streams containing emulsified coolants and lubricants such as
machining and grinding coolants, and impact and pressure deformation lubricants. This
technology is also applicable to cleaning solutions that contain emulsified oils. A flow
diagram of a type of chemical emulsion breaking system is shown in Figure 10-13.
Treatment of spent oil/water emulsions involves using chemicals to break the emulsion
followed by gravity differential separation. The major equipment required for chemical
emulsion breaking includes reaction chambers with agitators, chemical storage tanks,
chemical feed systems, pumps, and piping. Factors to be considered for destroying
emulsions are type of chemicals, dosage and sequence of addition, pH, mixing, heating
requirements, and retention time.
Chemicals (e.g., polymers, alum, ferric chloride, and organic emulsion breakers) destroy
emulsions by neutralizing repulsive charges between particles, precipitating or salting out
emulsifying agents, or weakening the interfacial film between the oil and water so it is
readily broken. Reactive cations (e.g., H+1, Al+3, Fe+3) and cationic polymers are
particularly effective in destroying dilute oil/water emulsions. Once the charges have
been neutralized or the interfacial film broken, the small oil droplets and suspended
solids either adsorb on the surface of the floe that is formed, or break out and float to
the top. Different types of emulsion-breaking chemicals are used for different types of
oils. If more than one chemical is required, the sequence of addition can affect both
breaking efficiency and chemical dosages.
Another important consideration in emulsion breaking is pH, especially if cationic
inorganic chemicals, such as alum, are used as coagulants. For example, a pH between 2
and 4 keeps the aluminum ion in its most positive state where it can function most
effectively to neutralize charges. After some of the oil is broken free and skimmed,
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raising the pH into the 6-to-8 range with lime or caustic causes the aluminum to
hydrolyze and precipitate as aluminum hydroxide. This floe entraps or adsorbs
destabilized oil droplets, which can then be separated from the water. Cationic polymers
can break emulsions over a wider pH range and thus avoid acid corrosion and the
additional sludge generated from neutralization; however, an inorganic flocculent is
usually required to supplement the polymer emulsion breaker's adsorptive properties.
Mixing is important in effectively breaking oil/water emulsions because it provides
proper chemical feed and dispersion. Mixing also causes collisions of droplets which
help break the emulsion, and subsequently helps to agglomerate droplets. Heating also
improves the performance of chemical emulsion breaking by lowering the viscosity and
increasing the apparent specific gravity differential between oil and water. Heating also
increases the frequency of droplet collisions, which helps to rupture the interfacial film.
Once an emulsion is broken, the difference in specific gravities between the oil and the
water results in the oil floating to the surface of the water. Solids usually form a layer
between the oil and water, since some solids become suspended in the oil. The longer
the retention time, the more complete the separation between the oil, solids, and water.
Oils and solids are typically skimmed from the surface of the water in a subsequent step
after chemical emulsion breaking. Often, other methods of separation, such as air
flotation or rotational separation (e.g., centrifugation), are used to enhance separation
after chemical emulsion breaking.
The advantages of chemical emulsion breaking are the high removal efficiency potential
and the possibility of reclaiming the oily waste. Disadvantages include corrosion
problems associated with acid-alum systems, skilled operator requirements for batch
treatment, chemical sludges produced, and poor cost-effectiveness for low oil
concentrations.
Chemical emulsion breaking is a very reliable process. The main control parameters are
pH and temperature. Maintenance is required on pumps, mixers, instrumentation and
valves, as well as periodic cleaning of the treatment tank to remove any accumulated
solids. Energy use is typically limited to mixers and pumps, but can also include heating.
Solid wastes generated by chemical emulsion breaking include surface oil and oily sludge,
which are usually contract hauled for disposal by a licensed contractor. If the recovered
oil has a sufficiently low percentage of water, the oil may be burned for its fuel value or
processed and reused.
Oil Skimming
Oil skimming is a physical separation technology that uses the difference in specific
gravity between oils and water to remove free or floating oil from wastewater. Common
separation devices include belt, rotating drum, disk, and weir oil skimmers and coalesces.
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These devices are not suited to remove emulsified oil, which requires chemical
treatment, membrane filtration, or other technologies. Flow diagrams of several types of
oil skimming are shown in Figure 10-14.
To separate oil process solutions, these devices are typically mounted onto the side of a
tank and are operated on a continuous basis. The disk skimmer consists of a vertically
rotating disk that is partially submerged in the solution. The disk continuously revolves
between spring loaded wiper blades that are located above the liquid surface. Its
adhesive characteristics cause the floating oil to remain on the disk. As the disk's
surface passes under the wiper blades, the oil is scraped off and diverted to a run-off
spout for collection. Belt and drum skimmers operate in a similar manner, with either a
continuous belt or drum rotating partially submerged in a tank. As the surface of the
belt or drum emerges from the liquid, the oil that adheres to the surface is scraped off
(drum) or squeezed off (belt) and diverted to a collection vessel. The oil is typically
contract hauled for disposal.
Gravity separators use overflow and underflow baffles to skim a floating oil layer from
the surface of the wastewater. An underflow baffle allows the oil layer to flow over into
a trough for disposal or reuse while most of the water flows underneath the baffle. This
is followed by an overflow baffle, which is set at a height relative to the first baffle such
that only the oil-bearing portion will flow over the first baffle during normal plant
operation. A diffusion device, such as a vertical slot baffle, aids in creating a uniform
flow through the system and in increasing oil removal efficiency.
The removal efficiency of a skimmer is partly a function of the retention time of the
water in the tank. Larger, more buoyant particles require less retention time than
smaller particles. Thus, the efficiency also depends on the composition of the waste
stream. The retention time required to allow phase separation and subsequent skimming
varies from 1 to 15 minutes, depending on the wastewater characteristics.
Gravity-type separators tend to be more effective for wastewater streams with
consistently large amounts of surface oil. Drum and belt type skimmers are more
applicable to waste streams containing smaller amounts of floating oil. Using a gravity
separator system in conjunction with a drum-type skimmer is an effective method of
removing floating contaminants from nonemulsified oily waste streams.
Coalescers are used to remove oil droplets too finely dispersed for conventional gravity
separation-skimming technology. Coalescing also reduces the residence times (and
therefore separator volumes) required for separation of oil from some wastes. The basic
principle of coalescence involves the attraction of oil droplets to the coalescing medium.
The oil droplets accumulate on the medium and then rise to the surface of the solution
as they combine to form larger particles. The most important requirements for
coalescing media are attraction for oil and large surface area. Coalescing media include
polypropylene, ceramic, or glass.
10-26
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10.0 TECHNOLOGY OPTIONS
Coalescing stages may be integrated with a wide variety of gravity oil separators, and
some systems may incorporate several coalescing stages. In general, a preliminary oil
skimming step is desirable to avoid overloading the coalescer.
Skimming which removes oil may also remove organic pollutants. Sampling data show
that many organic compounds are removed in standard wastewater treatment equipment.
Oil separation not only removes oil but also organics that are more soluble in oil than in
water. Subsequent clarification removes organic solids directly and probably removes
dissolved organics by adsorption on inorganic solids. Sources of these organic pollutants
are not always known with certainty, although in MP&M operations they are mainly
process coolants and lubricants, additives to formulations of cleaners, paint formulations,
or leaching from plastic lines and other materials.
A review of organic compounds commonly found in MP&M waste streams indicated that
these compounds are often removed as a result of oil removal and subsequent
clarification processes. When all organics analyses from sampled sites are considered,
removal of organic compounds appears to be marginal in many cases. However, when
only raw waste concentrations of 0.05 mg/L or greater are considered, incidental
organics removal becomes much more apparent. Lower values (those less than 0.05
mg/L), are much more subject to analytical variation, while higher values indicate a
significant presence of a given compound. When these factors are taken into account,
analytical data indicate that most oil removal and subsequent clarification systems can
remove priority organic compounds present in the raw waste.
Data from four sampling days at one site demonstrate removal of organics by the
combined chemical emulsion breaking and oil skimming operations performed at MP&M
sites. Days were selected where treatment system influent and effluent analyses provided
paired data points for oil and grease and the organics present. All organics found at
quantifiable levels on those days were included. Further, only those days were chosen
where oil and grease raw wastewater concentrations exceeded 10 mg/L and where there
was reduction in oil and grease going through the treatment system. All site sampling
days which met the above criteria were included. The average percent removal for
organic pollutants with sufficient data to assess treatment effectiveness was 64%, while
the average percent removal for oil and grease was 89 percent. These data indicate that
when oil and grease are removed, organics also are removed.
10.5 Technology descriptions for End-of-Pipe Treatment Technologies
This section describes in detail end-of-pipe technologies included in the MP&M
technology options or believed to be equivalent or alternative to a technology included in
10-27
-------
10.0 TECHNOLOGY OPTIONS
the MP&M technology options. Technology descriptions contain information on the
application and performance of the following technologies:
• Chemical precipitation and sedimentation;
• Reverse osmosis; and
• Ion exchange.
10.5.1 Chemical Precipitation and Sedimentation
Chemical precipitation and sedimentation is a common process used to remove dissolved
metals from wastewater. The dissolved metals are converted to an insoluble form and
separated from the wastewater. The process is usually performed on a continuous basis
in a series of two or three tanks, but can be performed on a batch basis in a single tank.
There are several basic methods of performing this process and many variations of each
method. The four most common methods are described below. A general flow diagram
of a chemical precipitation system is shown in Figure 10-15.
Hydroxide Precipitation. Hydroxide precipitation is the most common method of metals
removal from MP&M wastewater. This process was used to develop the MP&M
technology effectiveness concentrations (see Section 11.0) and compliance cost estimates
(see Section 12.0). This process is typically performed in several stages. In an initial
tank, which is mechanically agitated, alkaline treatment reagents such as lime (calcium
hydroxide or hydrated lime), sodium hydroxide, or magnesium hydroxide are added to
the wastewater to precipitate metal ions as metal hydroxides. The reaction is illustrated
by the following equation for precipitation of a divalent metal using lime:
M2* + Ca(OH). -^ M(OH). + CA2+ (10-5)
The precipitation process is usually operated at a pH of between 8.5 and 10.0, depending
on the types of metals in the wastewater. The pH set-point should be selected based on
testing to choose a value at which metals are most effectively removed. The effect of pH
on hydroxide precipitation is shown in Figure 10-16.
As shown in this figure, most metal hydroxides have an optimum pH at which the metal
is most effectively removed. After precipitation, the metal hydroxide particles are very
fine and are resistant to settling. To foster particle growth and improve the settling
characteristics of the metal hydroxides, coagulating and flocculating agents are added,
usually in a second tank, and slowly mixed. Coagulating and flocculating agents include
inorganic chemicals such as alum and ferrous sulfate, and a highly diverse range of
organic polyelectrolytes with varying characteristics suitable for different wastewaters.
The particles are then settled in a separate tank (e.g., clarifier), under quiescent
conditions, due to the difference in density between the solid particles and the
10-28
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10.0 TECHNOLOGY OPTIONS
wastewater. The solids are removed from the settling tank by drawing them from the
bottom of the tank, and then transferred to a thickener or other dewatering process.
Sulfide Precipitation. The sulfide precipitation process uses similar equipment as that
used for hydroxide precipitation. The major difference between the two processes is the
treatment reagents used. Sulfide precipitation uses either soluble sulfides (e.g., hydrogen
sulfide or sodium sulfide) or insoluble sulfides (e.g., ferrous sulfide) in place of alkali
reagents used for hydroxide precipitation. The sulfide reagents precipitate dissolved
metals as metal sulfides, which have lower solubility limits than metal hydroxides.
Therefore, the sulfide precipitation process can achieve lower levels of residual dissolved
metal in the treated effluent (see Figure 10-16). The reaction is illustrated by the
following equation for sulfide precipitation of a divalent metal:
M2+ + FeS ^ MS + Fe2+ (10'6)
Sulfide can precipitate most chelated metals and can be used to remove hexavalent
chromium without first reducing the chromium to its trivalent state.
The major disadvantages of sulfide precipitation as compared with hydroxide
precipitation are higher capital and operating costs and larger sludge generation rates
due to the liberation and subsequent precipitation of ferrous ions. Additional
disadvantages of sulfide precipitation are the potential for toxic hydrogen sulfide gas
generation, the potential for release of excessive sulfide in the effluent, and the
generation of sulfide odors. These can be controlled through proper operation and
maintenance of the sulfide precipitation system.
Carbonate Precipitation. Carbonate precipitation typically uses sodium carbonate (soda
ash), sodium bicarbonate, or calcium carbonate to form insoluble metal carbonates. The
reaction is illustrated by the following equation for sodium carbonate precipitation of a
divalent metal:
M2+ + Na2CO3 -* MCO3 + 2Na+ (10-7)
Carbonate precipitation is similar in operation to hydroxide precipitation, and is typically
performed to remove metals such as cadmium or lead. For these metals, carbonate
precipitation can achieve effluent concentrations similar to those achieved by hydroxide
precipitation, but typically at a lower operating pH. Carbonate precipitation and
hydroxide precipitation are sometimes performed in conjunction, which may improve the
overall performance of certain systems.
10-29
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10.0 TECHNOLOGY OPTIONS
Carbonate precipitation is less popular than hydroxide precipitation due to the higher
cost of treatment reagents and certain operational problems, such as the release of
carbon dioxide gas, which can result in foaming and/or floating sludge. This process is
not effective for all metals.
Sodium Borohydride Precipitation. Sodium borohydride precipitation uses sodium
borohydride as a reducing agent to precipitate metals from solution as insoluble
elemental metals. This reaction is illustrated by the following equations for precipitation
of a divalent metal:
4M2+ + NaBH4 + 2H2O -» NaBO2 + 4M + 8H + (10-8)
4M2+ + NaBH4 + BOH' -» NaBO2 + 4M + 6H2O
This process is similar in operation to hydroxide precipitation. Borohydride precipitation
is usually performed in a pH range of 8 to 11 to ensure efficient utilization of
borohydride. The optimum pH is determined by testing borohydride usage, reaction
time, and effluent quality.
Sodium borohydride precipitation is effective for removing lead, mercury, nickel, copper,
cadmium, and precious metals such as gold, silver, and platinum from wastewaters. This
process has also been reported to reduce sludge generation by 50% over lime
precipitation.
Chemical precipitation and sedimentation is a highly reliable technology when proper
monitoring and control are used. The effectiveness of metal precipitation and
sedimentation processes depends on the types of equipment used and numerous
operating factors, such as the characteristics of the raw wastewater, types of treatment
reagents used, and operating pH. In some cases, it is necessary to vary operational
factors to achieve sufficiently low effluent concentrations. Often, subtle changes such as
varying the operating pH or extending the reaction time of the process may sufficiently
improve its efficiency. In other cases, modifications to the treatment system are
necessary. For example, some raw wastewaters contain chemicals that may interfere with
the precipitation of metals, in which cases, additional treatment reagents such as ferrous
sulfate, sodium hydrosulfate, aluminum sulfate, or calcium chloride may be required.
These chemicals may be added prior to or during the precipitation process to affect
substances causing the interference.
The types of equipment used for chemical precipitation and sedimentation vary widely.
Small batch operations can be performed in a single tank, usually having a conical
bottom that permits removal of settled solids. Continuous processes are usually
10-30
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10.0 TECHNOLOGY OPTIONS
performed in a series of tanks, including a rapid mix tank for mixing the precipitating
chemicals, a slow mix tank for addition of coagulants and flocculants and floe formation,
and a settling tank or clarifier for separation of the solids from the wastewater. An
alternative method of separating precipitated solids from wastewater is filtration, during
which the entire wastewater flow is passed through a filter press (only applicable to very
low wastewater flows) or a membrane filter (e.g., ultrafiltration). When membrane
filters are used, the coagulation and flocculatlon step is omitted because these chemicals
can plug the small pores of the membrane.
Chemical precipitation and sedimentation systems require routine maintenance to assure
proper operation. Routine maintenance includes calibration of instrumentation and
cleaning of probes; transfer and chemical pumps and mixers (inspection, cleaning,
lubrication, replacing seals and packing, replacing check valves, cleaning strainers); and
tank and sump maintenance (inspection, cleaning, corrosion prevention).
10.5.2 Reverse Osmosis (End-of-Pipe)
Reverse osmosis is a membrane separation technology used by the MP&M industry as an
in-process step or as an end-of-pipe treatment. In-process reverse osmosis is discussed in
Section 10.3.
In an end-of-pipe application, reverse osmosis is typically performed to recycle water and
reduce discharge volume rather than recover chemicals. The effluent from a
conventional treatment system generally has a TDS concentration unacceptable for most
rinsing operations, and cannot be recycled. These TDS concentrations can be tolerated
by reverse osmosis membranes with or without some pretreatment, and the effluent
stream is acceptable for most rinsing operations.
10.5.3 Ion Exchange (end-of-pipe)
Ion exchange is used for both in-process and end-of-pipe applications. In-process ion
exchange is discussed in Section 10.3.6. End-of-pipe ion exchange is typically used as a
final polishing step, or to recycle water. End-of-pipe ion exchange usually employs
cation resins to remove metals but sometimes both cation and anion columns are used.
The regenerant from end-of-pipe ion exchange is not usually amenable to metal recovery
as it is usually more dilute and is not specific to a metal type.
10.6 Technology Descriptions for Sludge Handling and Disposal Technologies
This section describes in detail sludge handling and disposal technologies included in the
MP&M technology options or believed by the agency to be equivalent or alternative to a
10-31
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10.0 TECHNOLOGY OPTIONS
technology included in the MP&M technology options. Technology descriptions contain
information on the application of the following technologies:
• Gravity thickening;
• Pressure filtration;
• Sludge drying; or
• Vacuum filtration.
10.6.1 Gravity Thickening
Gravity thickening is a physical liquid-solid separation technology used to dewater
wastewater treatment sludge. Sludge is fed from a primary settling tank or clarifier to a
thickening tank, where gravity separates the supernatant from the sludge, increasing the
sludge density. The supernatant is returned to the primary settling tank. The thickened
sludge that collects on the bottom of the tank is pumped to additional dewatering
equipment or contract hauled for disposal. Figure 10-17 shows the diagram of a gravity
thickener.
Gravity thickeners are generally used in facilities where the sludge is to be further
dewatered by a mechanical device, such as a filter press. Increasing the solids content in
the thickener substantially reduces capital and operating costs of the subsequent
dewatering device and also reduces the hauling cost. The process is potentially
applicable to any MP&M site that generates sludge.
10.6.2 Pressure Filtration
The filter press is the most common type of pressure filtration used in the MP&M
industry for dewatering wastewater treatment sludges. A filter press consists of a series
of parallel plates pressed together by a hydraulic ram (older models may have a hand
crank), with cavities between the plates. Figure 10-18 presents a diagram of a plate-and-
frame filter press. The filter press plates are concave on each side to form cavities and
are covered with a filter cloth. At the start of a cycle, a hydraulic pump clamps the
plates tightly together and a feed pump forces a sludge slurry into the cavities of the
plates. The liquid (filtrate) escapes through the filter cloth and grooves molded into the
plates and is transported by the pressure of the feed pump (typically around 100 psi) to a
discharge port. The solids are retained by the cloth and remain in the cavities. This
process continues until the cavities are packed with sludge solids. An air blow-down
manifold is used on some units at the end of the filtration cycle to drain remaining liquid
from the system, thereby improving sludge dryness and aiding in the release of the cake.
The pressure is then released and the plates are separated.
The sludge solids or cake is loosened from the cavities and falls into a hopper or drum.
A plate filter press can produce a sludge cake with a dryness of approximately 25 to 40
percent solids for metal hydroxides precipitated with sodium hydroxide, and 35 to
10-32
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10.0 TECHNOLOGY OPTIONS
60 percent solids for metal hydroxides precipitated with calcium hydroxide. The solids
content attained depends on the length of the drying cycle. Filter presses are available
in a very wide range of capacities (0.6 ft3 to 20 ft3). A typical operating cycle is from 4
to 8 hours, depending on the dewatering characteristics of the sludge. Units are usually
sized based on one or two cycles per day.
10.6.3 Sludge Drying
Wastewater treatment sludges are often hauled long distances to disposal sites. The
transportation and disposal costs depend mostly on the volume of sludge. Therefore,
many MP&M sites use sludge dehydration equipment following dewatering to further
reduce the volume of the sludge.
The solids content of the sludge dewatered on a filter press is usually in the range of
25 to 60 percent. Dehydration equipment can produce a waste material with a solids
content of approximately 90 percent.
There are several design variations for sludge dehydration equipment. A commonly used
type is a sludge drying unit that uses an auger or conveyor system to move a thin layer of
sludge through a drying region and discharge it into a hopper. Various heat sources are
used for sludge drying, including electric, electric infrared, steam, and gas. Some
continuous units are designed such that the sludge cake discharge from a filter press
drops into the feed hopper of the dehydration unit, making the overall dewatering
process more automated. System capacities range from less than 1 ft3/hr to more than
20 ft3/hr of feed. Sludge dehydration equipment requires an air exhaust system due to
the fumes generated during drying.
Energy requirements depend mostly on the water content of the feed stock and the
efficiency of a given unit. Sludge drying was not included in the preferred technology
options for MP&M due to space constraints, energy requirements, and possible cross-
media impacts.
10.6.4 Vacuum Filtration
Vacuum filtration is performed at some MP&M sites to reduce the water content of
sludge, increasing the solids content from approximately 5 percent to between 20 and
30 percent. At these MP&M sites, sludge dewatering by vacuum filtration generally uses
cylindrical drum filters. The filters on these drums are typically either cloth made of
natural or synthetic fibers or a wire-mesh fabric. The drum is dipped into a vat of sludge
and rotates slowly, creating an internal vacuum that draws sludge to the filter. Water is
drawn through the porous filter cake through the filter to a discharge port, and the
dewatered sludge is scraped from the filter. Because dewatering sludges using vacuum
filters is relatively expensive per kilogram of water removed, the liquid sludge is
10-33
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10.0 TECHNOLOGY OPTIONS
frequently gravity thickened prior to vacuum filtration. Figure 10-19 shows a typical
vacuum filter.
Vacuum filters are frequently used both in municipal treatment plants and in a wide
variety of industries. They are most commonly used in larger facilities, which may have
a thickener to double the solids content of clarifier sludge before vacuum filtering.
Often a precoat is used to inhibit filter binding.
Maintenance of vacuum filters involves cleaning or replacing the filter media, drainage
grids, drainage piping, filter parts, and other parts. Maintenance time may be as high as
20% of total operating time; therefore, it is desirable to maintain one or more spare
units. If intermittent operation is used, the filter equipment should be drained and
washed each time it is taken out of service, and an allowance for this wash time made in
filtering schedules.
Vacuum filtration was not included in the preferred technology options for MP&M
because it was estimated that pressure filtration could achieve a greater solids
percentage.
10-34
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MP&M Source Reduction Technologies
Technology
Technology Description
Demonstration
Status
Number of Site
Visits1
Comments
Conductivity Probes
Conductivity probes measure the conductivity of water in a
rinse tank to regulate the flow of fresh rinse water into the
rinse system. A solenoid valve on the rinse system fresh water
supply is connected to the controller, which opens the valve
when a preset conductivity level is exceeded and closes the
valve when conductivity is below that level.
20
Included in the technology options.
Reduces excessive rinsing.
Countercurrent Cascade
Rinsing
Countercurrent cascade rinsing refers to a series of consecutive
rinse tanks which are plumbed to cause water to flow from one
tank to another in the direction opposite of the work flow.
Water is introduced into the last tank of the series, making it
the cleanest, and is discharged from the first tank, which will
have the highest concentration of contaminants.
48
Included in the technology options.
This technology reduces the amount of
water necessary for rinsing by up to
90% per stage.
Drag-Out Rinsing
A drag-out rinse is a stagnant rinse, initially filled with fresh
water, positioned immediately after process tanks. The drag-
out rinse collects the majority of the drag-out from the process
tank, preventing it from entering the subsequent flowing rinses.
Drag-out can be recovered by returning the contents of these
tanks to the process tank. Electrolytic recovery of dissolved
metals from drag-out tanks is also common.
21
This technology is included in the
technology options as part of the ion-
exchange/electrolytic recovery system.
Flow Restrictors
A flow restrictor prevents the flow in a pipe from exceeding a
predetermined volume. Flow restrictors can be used to limit
the flow into a rinse system. For continuously flowing rinses, a
flow restrictor controls the flow into the system, ensuring a
consistent, optimum flow rate.
17
Part of technology options. Reduces
excessive rinsing.
'Indicates the number of MP&M Phase I sites visited by EPA at which the technology was used. The Site Visit Report Database contains data from 80 Phase I sites.
-------
Table 10-1 (Continued)
MP&M Source Reduction Technologies
Technology
Technology Description
Demonstration
Status
Number of Site
Visits1
Comments
Plant Maintenance and
Good Housekeeping
Plant maintenance and good housekeeping include in-plant
practices such as immediate repair of leaks, maintenance of
process lines, training of equipment operators, etc.
45
The benefits of these practices are not
quantifiable. These practices are not
included in the technology options.
Regeneration of
Chemical Baths
Regeneration, rather than treatment and disposal, can be
accomplished by various technologies. These include filtration,
precipitation, and membrane-based purification technologies.
24
These technologies are not applicable
at all sites and are not included in the
technology options.
p
u>
ON
Spray Rinsing Over
Process Bath
The installation of low-flow spray rinses over a process bath
greatly reduces drag-out into subsequent rinses. The flow rate
of the rinse should equal the evaporation rate of the process
tank.
This technology is not applicable at all
sites because of part and process
configurations, and is not included in
the technology options.
Spray Rinsing with
Discharge
For certain part configurations, spray rinsing uses considerably
less water than immersion. This technology can be performed
as countercurrent cascade rinsing with spray rinses instead of
overflow immersion rinses.
46
This technology is not applicable at all
sites because of part and process
configurations, and is not included in
the technology options.
Activated Carbon
Adsorption of Painting
Water Curtains
Activated carbon adsorption can remove dissolved organics
from paint overspray. Pretreatment for solids removal may be
necessary. Closed loop reuse of water curtains can be achieved
with this technology.
This technology requires pretreatment
for solids removal and periodic
regeneration of activated carbon. A
centrifugation is included in
technology options to achieve zero
discharge of painting water curtains;
therefore, this technology is not
included in the technology options.
'Indicates the number of MP&M Phase I sites visited by EPA at which the technology was used. The Site Visit Report Database contains data from 80 Phase I sites.
-------
MP&M Source Reduction Technologies
Technology
Technology Description
Demonstration
Status
Number of Site
Visits1
Comments
Centrifugation of
Painting Water Curtains
Centrifugation removes the heavier solids from the water
curtain allowing reuse. The solids are collected as a cake in
the basket of the centrifuge. Closed loop reuse of water
curtains may be achieved with this technology.
This technology requires little
maintenance, and has been
demonstrated to achieve complete
recycle with periodic removal of
sludge. This technology is included in
the technology options.
Filtration of Painting
Water Curtains
Removal of solids by filtration (cloth, sand, diatomaceous
earth, etc.) followed by reuse. Closed loop reuse of water
curtains may be achieved with this technology.
Generates more waste than
Centrifugation due to filter medium
disposal or sand filter backwash. This
technology is not included in the
technology options.
Settling of Painting
Water Curtains
Settling removes the heavier solids from the water curtains.
This technology can be used in conjunction with other removal
technologies to lessen the solids loading.
Equivalent technology (centrifugation)
included as part of the technology
options; therefore, this technology is
not included in the technology option.
Biocide Addition to
Lengthen Coolant Life
Machining coolant is often discarded as it becomes rancid.
Addition of a biocide can impede the growth of
microorganisms that cause rancidity.
Equivalent technology (pasteurization)
is included as part of the technology
options; therefore, this technology is
not included in the technology option.
Centrifugation to
Lengthen Coolant Life
Centrifugation removes the solids from the coolant to extend
its usable life. Some high-speed centrifuges can also perform
liquid-liquid separation for the removal of tramp oils and
further extension of coolant life.
11
This technology is a component of the
coolant recycling system included in
the technology options.
'Indicates the number of MP&M Phase I sites visited by EPA at which the technology was used. The Site Visit Report Database contains data from 80 Phase I sites.
-------
Table 10-1 (Continued)
MP&M Source Reduction Technologies
Technology
Technology Description
Demonstration
Status
Number of Site
Visits1
Comments
Filtration to Lengthen
Coolant Life
Filtration removes the solids from the coolant. These filters
include cloth, sand, carbon, etc.
Equivalent technology (liquid-liquid
centrifugation) is included as part of
the technology options; therefore, this
technology is not included in the
technology options.
Oil Skimming of Tramp
Oils to Lengthen Coolant
Life
Tramp oil buildup often causes machining coolant to be no
longer usable. Oil skimming with belt skimmers, disk
skimmers, etc., extends the coolant life.
9
OJ
00
Equivalent technology (liquid-liquid
centrifugation) is included as part of
the technology options; therefore, this
technology is not included in the
technology options.
Machining coolant is often discarded as it becomes rancid.
Pasteurization kills the microorganisms that cause rancidity.
Pasteurization to
Lengthen Coolant Life
This technology is a component of the
coolant recycling system included in
the technology options.
In-Tank Filtration to
Lengthen the Life of
Concentrated Baths
Filtration to remove accumulated suspended solids, precipitant,
or dissolved contaminants extends the life of some process
fluids. Suspended solids are removed with paper, cloth, or
plastic filters. Activated carbon removes organics.
12
This technology is not applicable at all
sites and is not included in the
technology options.
In-Process Ion Exchange
Removes contaminants from concentrated baths or rinse water
and creates concentrated regenerant streams that can be
reclaimed by electrolytic recovery, reused in the process bath,
or discharged. Can achieve significant rinse water use
reduction for electroplating.
10
This technology is included in the
technology options for certain
electroplating rinses.
'Indicates the number of MP&M Phase I sites visited by EPA at which the technology was used. The Site Visit Report Database contains data from 80 Phase I sites.
-------
laoie iu-1
MP&M Source Reduction Technologies
Technology
Technology Description
Demonstration
Status
Number of Site
Visits1
Comments
In-Process Reverse
Osmosis
Reverse osmosis is used to recover drag-out or rinse water. In
most cases, the purified water is suitable for reuse. The reject
stream is usually less concentrated than process baths, but is
suitable for reuse in heated baths that create evaporative
headroom. The reject stream can also be reclaimed by
electrolytic recovery.
This technology is similar in
application to in-process ion-exchange
but is not applicable to as many unit
operation-metal type combinations and
is not as well demonstrated. This
technology is not included in the
technology options.
Source: MP&M site visits, MP&M sampling episodes, MP&M DCPs, technical literature.
'Indicates the number of MP&M Phase I sites visited by EPA at which the technology was used. The Site Visit Report Database contains data from 80 Phase I sites.
-------
Table 10-2
MP&M Recycling Technologies
Technology
Evaporation with
Condensate Recovery
Ion Exchange
Reverse Osmosis
Technology Description
Evaporation of wastewater, leaving a
concentrated residue for disposal, and
condensing the water vapor for reuse.
Ion exchange can be used at the end-of-
pipe as a final polishing step. Ion exchange
polishing is done with a cation (scavenger)
column only. Anions remain in solution
and are discharged. This can be used as a
stand alone technique or a polishing
technique after metals precipitation. In
cases where recycle is desired, both cation
and anion columns are necessary.
Membrane filtration in which the
wastewater is forced through the membrane
at high pressure leaving a concentrated
stream of pollutants for disposal. Reverse
osmosis may provide an effluent clean
enough for reuse.
Demonstration Status
Number
of Site
Visits1
1
3
1
Number
of Model
Sites2
NA
7
0
Estimated Number
of MP&M Phase I
Sites3
NA
34
0
Comments
This unit operation is very energy
intensive. This technology is not
included in the technology options.
Permeate contains moderate
dissolved solids concentrations and
reuse may be limited to non-critical
unit operations. This technology is
included in the technology options.
Similar in application to end-of-pipe
ion-exchange, but not as well
demonstrated. This technology is
not included in the technology
options.
o
o
NA - Numerical data are not available.
'Indicates the number of visited MP&M Phase I sites at which the technology was used. The Site Visit Report Database contains data from Phase I 80 sites.
Indicates the number of model sites that indicated use of this technology. These data are not available for in-process technologies. Based on the 396 dcp respondents used as model sites.
'Indicates the estimated number of MP&M Phase I sites currently performing this technology. EPA estimates that MP&M Phase I includes 10,601 sites. The numbers in this column were
calculated using statistical weighting factors for the dcp respondents.
-------
A CIILFI.V' AV^JW
MP&M Recycling Technologies
Technology
Electrolytic Recovery
(Electrowinning)
Technology Description
Dissolved metals are recovered from
concentrated sources with this technology.
For rinses, electrolytic recovery is typically
restricted to drag-out rinses. Flowing rinses
are generally too dilute for efficient
electrolytic recovery. This technology is
effective on the concentrated regenerant
from ion-exchange.
Demonstration Status
Number
of Site
Visits1
11
Number
of Model
Sites2
NA
Estimated Number
of MP&M Phase I
Sites3
NA
Comments
This technology works in
conjunction with drag-out rinsing
and in-process ion exchange to
recovery metals from wastewater.
This technology is included in the
technology options.
Source: MP&M site visits, MP&M sampling episodes, MP&M DCPs, technical literature.
NA - Numerical data are not available.
'Indicates the number of visited MP&M Phase I sites at which the technology was used. The Site Visit Report Database contains data from Phase I 80 sites.
indicates the number of model sites that indicated use of this technology. These data are not available for in-process technologies. Based on the 396 dcp respondents used as model sites.
'Indicates the estimated number of MP&M Phase I sites currently performing this technology. EPA estimates that MP&M Phase I includes 10,601 sites. The numbers in this column were
calculated using statistical weighting factors for the dcp respondents.
-------
Table 10-3
MP&M End-of-Pipe Treatment and Disposal Technologies
Technology
Chemical Emulsion
Breaking
Chemical Reduction of
Hexavalent Chromium
Cyanide Destruction
Through Alkaline
Chlorination
Flotation of Oils or
Solids
Technology Description
Addition of acids (typically sulfuric)
to oil-bearing wastewater to break
oil/water emulsions for subsequent
gravity separation.
Reduction of hexavalent chromium to
trivalent chromium using a reducing
agent such as sulfur dioxide, sodium
bisulfite, or sodium metabisulfite.
Destruction of cyanide by adding
chlorine (usually sodium hypochlorite
or chlorine gas) to first oxidize
cyanide to cyanate, then cyanate to
carbon dioxide and nitrogen gas.
Removal of oils or solids by bubbling
gas through the wastewater, bringing
solids to the surface for subsequent
removal.
Demonstration Status
Number of
Site Visits1
6
43
27
3
Number of
Model Sites2
16
65
24
9
Estimated Number of
MP&M Phase I Sites*
207
753
337
96
Comments
This technology is included in the
technology options.
This technology is included in the
technology options.
This technology is included in the
technology options.
Based on analytical data collected for
the MP&M sampling program, this
technology is not as effective as
oil/water separation followed by
chemical precipitation and
sedimentation. Therefore, this
technology is not included in the
technology options.
NA - Numerical data are not available.
'Indicates the number of visited MP&M Phase I sites at which the technology was used. The Site Visit Report Database contains data from Phase I 80 sites.
Indicates the number of model sites that indicated use of this technology. These data are not available for in-process technologies. Based on the 396 dcp respondents used as model sites.
'Indicates the estimated number of MP&M Phase I sites currently performing this technology. EPA estimates that MP&M Phase I includes 10,601 sites. The numbers in this column were
calculated using statistical weighting factors for the dcp respondents.
-------
ICtUIC
MP&M End-of-Pipe Treatment Technologies and Disposal Technologies
Technology
Technology Description
Demonstration Status
Number of
Site Visits1
Number of
Model Sites2
Estimated Number of
MP&M Phase I Sites3
Comments
Oil Skimming of Oily
Wastewater Streams
Removal of free floating oil by gravity
separation and mechanical skimming.
This technology does not remove
emulsified oils.
23
50
480
This technology is included in the
technology options.
Cyanide Oxidation by
Ozone
Oxidation of cyanide by ozone.
Yields ammonia, carbon dioxide and
oxygen.
The generation of ozone requires
expensive equipment and safety
controls. This technology is not
included in the technology options. An
equivalent technology (cyanide
destruction through alkaline
chlorination) was included in the
technology options.
Ultrafiltration
Filtration using a membrane of very
small pore size. Generally used for
the removal of emulsified or free-
floating oils. This technology also
removes other solids.
15
171
Based on analytical data collected for
the MP&M sampling program, this
technology is not as effective as
oil/water separation followed by
chemical precipitation and
sedimentation. Therefore, this
technology is not included in the
technology options.
NA - Numerical data are not available.
'Indicates the number of visited MP&M Phase I sites at which the technology was used. The Site Visit Report Database contains data from Phase I 80 sites.
Indicates the number of model sites that indicated use of this technology. These data are not available for in-process technologies. Based on the 396 dcp respondents used as model sites.
'Indicates the estimated number of MP&M Phase I sites currently performing this technology. EPA estimates that MP&M Phase I includes 10,601 sites. The numbers in this column were
calculated using statistical weighting factors for the dcp respondents.
-------
Table 10-3 (Continued)
MP&M End-of-Pipe Treatment Technologies and Disposal Technologies
Technology
Technology Description
Demonstration Status
Number of
Site Visits1
Number of
Model Sites2
Estimated Number of
MP&M Phase I Sites3
Comments
Activated Carbon
Adsorption
Removal of dissolved organic
pollutants by filtration through
activated carbon. The dissolved
organics are removed by the process
of adsorption. This technology
requires preliminary treatment for
removal of suspended solids and oil
and grease.
73
Applicable to wastewaters containing
high concentrations of organic
pollutants. MP&M treatment influent
streams typically do not contain high
concentrations of organic pollutants.
This technology is not included in the
technology options.
Aerobic
Decomposition
The biochemical decomposition of
organic materials in the presence of
oxygen. The decomposition is
performed by microorganisms.
76
Applicable to wastewater with high
concentrations of organic pollutants.
MP&M treatment influent streams
typically do not contain high
concentrations of organic pollutants.
At the site at which technology was
observed, the technology was operated
to treat nonprocess wastewater
(contaminated groundwater). This
technology is not included in the
technology options.
NA - Numerical data are not available.
'Indicates the number of visited MP&M Phase I sites at which the technology was used. The Site Visit Report Database contains data from Phase I 80 sites.
Indicates the number of model sites that indicated use of this technology. These data are not available for in-process technologies. Based on the 396 dcp respondents used as model sites.
'Indicates the estimated number of MP&M Phase I sites currently performing this technology. EPA estimates that MP&M Phase I includes 10,601 sites. The numbers in this column were
calculated using statistical weighting factors for the dcp respondents.
-------
Table 10-3 (Continued)
MP&M End-of-Pipe Treatment Technologies and Disposal Technologies
Technology
Technology Description
Demonstration Status
Number of
Site Visits1
Number of
Model Sites2
Estimated Number of
MP&M Phase I Sites3
Comments
Air Stripping
Removal of dissolved organic
pollutants by contacting the organics
in the wastewater with a continuous
stream of air bubbles. Volatile
organic pollutants are transferred
from the wastewater to the air.
0
14
Applicable to wastewaters containing
high concentrations of organic
pollutants. MP&M treatment influent
streams typically do not contain high
concentrations of organic pollutants.
This technology is not included in the
technology options.
Neutralization
The neutralization of high or low pH
wastewater to within an acceptable
range with acidic or alkaline
chemicals. Common acids include
sulfuric and hydrochloric. Common
alkaline chemicals include lime
(calcium hydroxide) and sodium
hydroxide.
32
100
1,283
This technology adjusts pH, but does
not remove suspended solids and
dissolved metals. This technology is
not included in the technology options.
Chemical Precipitation
Sedimentation
Removal of metals by precipitating as
insoluble compounds such as
hydroxides, sulfides, or carbonates.
Precipitation as metal hydroxides
using lime (calcium hydroxide) or
sodium hydroxide is the most
common.
63
130
1,666
This technology is included in the
technology options.
NA - Numerical data are not available.
'Indicates the number of visited MP&M Phase I sites at which the technology was used. The Site Visit Report Database contains data from Phase I 80 sites.
Indicates the number of model sites that indicated use of this technology. These data are not available for in-process technologies. Based on the 396 dcp respondents used as model sites.
'Indicates the estimated number of MP&M Phase I sites currently performing this technology. EPA estimates that MP&M Phase I includes 10,601 sites. The numbers in this column were
calculated using statistical weighting factors for the dcp respondents.
-------
Table 10-3 (Continued)
MP&M End-of-Pipe Treatment Technologies and Disposal Technologies
Technology
Technology Description
Demonstration Status
Number of
Site Visits1
Number of
Model Sites2
Estimated Number of
MP&M Phase I Sites3
Comments
Atmospheric
Evaporation
Includes both natural solar
evaporation and forced atmospheric
evaporation by which the evaporation
rate is accelerated by increased
temperature, air flow, and surface
area.
54
Solar evaporation usually occurs in
ponds or lagoons with large space
requirements. Also, atmospheric
evaporators have significant energy
requirements as well as possible cross-
media impacts. This technology is not
included in the technology options.
Ion Exchange
9
4^
ON
Ion exchange can be used at the end-
of-pipe as a final polishing step. Ion
exchange polishing is done with a
cation (scavenger) column only.
Anions remain in solution and are
discharged. This can be used as a
stand alone technique or a polishing
technique after metals precipitation.
34
Usually used in conjunction with
another end-of-pipe technology (e.g.,
following chemical precipitation). This
technology is included in the
technology options.
NA - Numerical data are not available.
'Indicates the number of visited MP&M Phase I sites at which the technology was used. The Site Visit Report Database contains data from Phase I 80 sites.
Indicates the number of model sites that indicated use of this technology. These data are not available for in-process technologies. Based on the 396 dcp respondents used as model sites.
'Indicates the estimated number of MP&M Phase I sites currently performing this technology. EPA estimates that MP&M Phase I includes 10,601 sites. The numbers in this column were
calculated using statistical weighting factors for the dcp respondents.
-------
Table 10-3 (Continued)
MP&M End-of-Pipe Treatment Technologies and Disposal Technologies
Technology
Technology Description
Demonstration Status
Number of
Site Visits1
Number of
Model Sites2
Estimated Number of
MP&M Phase I Sites3
Comments
Multimedia Filtration
o
-k
-j
Filtration using media of different
grain size to remove solids from
wastewater. Larger particles are
removed by the coarser media and
the smaller particles are removed by
the finer media. Media include
garnet, sand, and anthracite coal.
The filter is periodically backwashed
to remove solids.
10
332
Usually used in conjunction with
another end-of-pipe technology (e.g.,
following chemical precipitation).
Based on analytical data collected for
the MP&M sampling program, this
technology does not provide additional
metal removals beyond chemical
precipitation and sedimentation. This
technology was considered for BCT
(see section 15) for TSS removal, but
is not included in the technology
options.
Sand Filtration
Single media filtration of wastewater
using sand. The filter is periodically
backwashed to remove solids.
21
19
258
Usually used in conjunction with
another end-of-pipe technology (e.g.,
following chemical precipitation).
Based on analytical data collected for
the MP&M sampling program, this
technology does not provide additional
metal removals beyond chemical
precipitation and sedimentation. This
technology is not included in the
technology options.
NA - Numerical data are not available.
'Indicates the number of visited MP&M Phase I sites at which the technology was used. The Site Visit Report Database contains data from Phase I 80 sites.
Indicates the number of model sites that indicated use of this technology. These data are not available for in-process technologies. Based on the 396 dcp respondents used as model sites.
'Indicates the estimated number of MP&M Phase I sites currently performing this technology. EPA estimates that MP&M Phase I includes 10,601 sites. The numbers in this column were
calculated using statistical weighting factors for the dcp respondents.
-------
Table 10-3 (Continued)
MP&M End-of-Pipe Treatment Technologies and Disposal Technologies
Technology
Technology Description
Demonstration Status
Number of
Site Visits1
Number of
Model Sites2
Estimated Number of
MP&M Phase I Sites3
Comments
Gravity Settling
The physical removal of suspended
particles by gravity. This process
does not include the addition of any
chemicals.
32
1,094
This technology only settles suspended
solids and does not remove dissolved
metals. This technology is not included
in the technology options.
Centrifugation of
Sludge
Use of centrifugal force to separate
water from solids. Centrifugation
dewaters sludges, reducing the volume
and creating a semi-solid cake.
Centrifugation of sludge can typically
achieve a sludge of 20-35% solids.
74
This technology is energy intensive, and
is therefore not included in the
technology options. Equivalent sludge
dewatering technologies (gravity
thickening and pressure filtration) are
included in the technology options.
p
oo
Gravity Thickening of
Sludge
Physical separation of solids and
water by gravity. Water separates
from the sludge and is decanted from
the top of the mixture. Gravity
thickening can typically thicken sludge
to 5% solids.
26
62
820
This technology is included in the
technology options.
NA - Numerical data are not available.
'Indicates the number of visited MP&M Phase I sites at which the technology was used. The Site Visit Report Database contains data from Phase I 80 sites.
Indicates the number of model sites that indicated use of this technology. These data are not available for in-process technologies. Based on the 396 dcp respondents used as model sites.
'Indicates the estimated number of MP&M Phase I sites currently performing this technology. EPA estimates that MP&M Phase I includes 10,601 sites. The numbers in this column were
calculated using statistical weighting factors for the dcp respondents.
-------
Table 10-3 (Continued)
MP&M End-of-Pipe Treatment Technologies and Disposal Technologies
Technology
Pressure Filtration of
Sludge
Sludge Drying
Technology Description
Physical separation of solids and
water by pressure filtration. This
technology is most commonly
performed in a plate-and-frame filter
press where the sludge builds up
between the filter plates and water is
filtered through a cloth. Pressure
filtration can produce a sludge cake
with greater than 40% solids.
Drying of sludge by heating causes
the water in the sludge to evaporate.
Demonstration Status
Number of
Site Visits1
49
11
Number of
Model Sites2
66
13
Estimated Number of
MP&M Phase I Sites3
1,003
140
Comments
This technology is included in the
technology options.
This technology is very energy
intensive, and is therefore not included
in the technology options. Equivalent
technologies (gravity thickening and
pressure filtration) are included in the
technology options.
NA - Numerical data are not available.
'Indicates the number of visited MP&M Phase I sites at which the technology was used. The Site Visit Report Database contains data from Phase I 80 sites.
'Indicates the number of model sites that indicated use of this technology. These data are not available for in-process technologies. Based on the 396 dcp respondents used as model sites.
'Indicates the estimated number of MP&M Phase I sites currently performing this technology. EPA estimates that MP&M Phase I includes 10,601 sites. The numbers in this column were
calculated using statistical weighting factors for the dcp respondents.
-------
Table 10-3 (Continued)
MP&M End-of-Pipe Treatment Technologies and Disposal Technologies
Technology
Technology Description
Demonstration Status
Number of
Site Visits1
Number of
Model Sites2
Estimated Number of
MP&M Phase I Sites3
Comments
Vacuum Filtration of
Sludge
Physical separation of solids and
water by drawing the sludge through
a cloth filter. The water passes
through the filter and the sludge is
scraped from the filter. The most
common type is the rotary drum
vacuum filter in which the sludge is
drawn from the outside towards the
inside of a rotating filter drum. The
filtrate leaves from the center while
the sludge is continuously scraped off
as the drum rotates.
7
132
This technology is very energy intensive
and typically does not achieve as high
of a percent solids as pressure
filtration. This technology is not
included in the technology options.
Equivalent sludge dewatering
technologies (gravity thickening and
pressure filtration) are included in the
technology options.
Source: MP&M site visits, MP&M sampling episodes, MP&M DCPs, technical literature.
NA - Numerical data are not available.
'Indicates the number of visited MP&M Phase I sites at which the technology was used. The Site Visit Report Database contains data from Phase I 80 sites.
Indicates the number of model sites that indicated use of this technology. These data are not available for in-process technologies. Based on the 396 dcp respondents used as model sites.
'Indicates the estimated number of MP&M Phase I sites currently performing this technology. EPA estimates that MP&M Phase I includes 10,601 sites. The numbers in this column were
calculated using statistical weighting factors for the dcp respondents.
-------
End-of-Pipe Technologies
GENERAL METAL-BEARING
O
Ui
PRECIPITATION
CHEMICALS
WASTEWATER
DISCHARGE
SLUDGE TO
DISPOSAL
Also includes contract hauling of organic
solvent-bearing wastewater.
BEARING WASTEWATER
The technologies included in each option were selected for
the development of the MP&M Phase I effluent limitations
guidelines and standards. These technologies are not
required for compliance with the MP&M Phase I effluent
guidelines; sites can install any technology as long as the
site achieves the final effluent limitations.
Figure 10-1. End-of-Pipe Technology Trains for MP&M Technology Options 1, 2, 1A, and 2A
-------
In-Process Technologies
9
Ln
NJ
*
Painting Water
Curtains
1 1
Centrifuge
4
RINSE WATER TO REUSE ™SH FRESH T WASTEWATER
1 SLUDGE
1 —
<— ' *J n
Electroplating PRODUCTS Drag-Out PRODUCTS r^,^,^,,, r^^ R-ncp RINSED KE--LED
operation "" Rinse *"" "PRODUCTS <^^.^c^
^ J, (8f>o/
Machining
Coolant
1
SPENT CO
_ . ,.., .., -., _ RP.rvn.Rn
RINSE WATER !„„,;„„»,„„„„ RINSE WATER L
REGENERATION CHEMICAL. KeVerSeUSnlOS1S'°r SPENT REGENERENT/ . Electrolytic
(ION EXCHANGE ONLY) Elccirodialysis CONCENTRATE ^ Recovery
1
RECOVERED METAL TO
... ,._. _. _. _^- SAI.F./RPIISR
, , ,.,.,, BLEED TO
In-process technologies also include: TREATMENT
• Flow reduction for all unit operations
• Countercurrent cascade rinsing for flowing rinses
OIL TO
RECLAIM
COOLANT ^
4> I
Centrifuge and
Pasteurization
4 1
OLANT ^t
SLUDGE
DISCHARGE TO
END-OF-PIPE
TREATMENT
w
DISCHARGE
TO
TREATMENT
(20%)
Figure 10-2. In-Process Technology Trains for MP&M Technology Options 1A, 2, 2A, and 3
-------
End-of-Pipe Technologies
GENERAL METAL-BEARING
U)
WASTEWATER
HEXAVALENT CHROMIUM- ^
BEARING WASTEWATER '
CYANIDE-BEARING ^
WASTEWATER
OILY WASTEWATER
CHELATED METALS- ^
BEARING WASTEWATER
REDUCING
AGENT
1
Chromium
Reduction
OXIDIZING
AGENT
Cyanide
Destruction
ACID
1
Chemical
Emulsion
Breaking
REDUCING AGENT
1
Chelated Metals
Treatment
^
t
p.
' i
i i
OIL TO
RECLAIM
t
Oil
Skimming ^
w
w
PRECIPITATION
CHEMICALS
I
Chemical
, Precipitation
>k (including ^ E
clarification)
SLUDGE
^
Slu
FILTRATE DCW3
r
ige
tering
^ SLUDGE TO
DISPOSAL
REGENERANT
(CONTRACT
HAULED)
Ion WASTEWATER
xchange DISCHARGE
(10%)
u
WATER REUSE
ON SITE
(90%)
Figure 10-3. End-of-Pipe Technology Train for MP&M Technology Option 3
-------
SPENT COOLANT
FROM PROCESS
SPENT COOLANT
HOLDING TANK
LIQUID-LIQUID/
LIQUID-SOLID
SEPARATION
CENTRIFUGE
SOLIDS OIL
TO TO
CONTRACT CONTRACT
HAUL HAUL
PASTEURIZATION
UNIT
RECYCLED COOLANT
HOLDING TANK
HEAT
BLEED TO
TREATMENT
OR
CONTRACT
HAUL
• HOLDING TANKS ARE USED FOR LARGER VOLUME APPLICATIONS. FOR SMALLER VOLUME APPLICATIONS, THE CENTRIFUGE
AND PASTEURIZATION UNIT CAN BE MADE PORTABLE AND TREATMENT CAN OCCUR FROM EACH INDIVIDUAL MACHINING
COOLANT SUMP.
• AN OIL SKIMMER CAN BE USED ON THE SPENT COOLANT HOLDING TANK IN WHICH CASE A SLOWER, LIQUID-SOLID
SEPARATION CENTRIFUGE COULD BE USED.
• BIOCIDE ADDITION CAN BE USED IN LIEU OF PASTEURIZATION.
RECYCLED
COOLANT
TO
PROCESS
Figure 10-4. Centrifugation and Pasteurization of Machining Coolants
-------
CHEMICAL ADDITION
(IF NECESSARY)
RECYCLED WATER
PAINT CURTAIN
SUMP
Spent Paint
Curtain Water
Holding
Tank
Spent Paint
Curtain Water
Centrifuge
Paint
Solids
To
Contract Haul
Paint
Solids
To
Contract Haul
Many sites also operate solids removal mechanisms on the paint curtain sump such as filtration and skimming
Figure 10-5. Centrifugation and Recycling of Painting Water Curtains
-------
TWO-STAGE COUNTERFLOW
RINSE
OUTGOING WATER-
-*-- P- WORK MOVEMENT
—- INCOMING
r— WATER
THREE-STAGE COUNTERFLOW
RINSE
WORK MOVEMENT
INCOMING
— WATER
OUTGOING WATER
Figure 10-6. Countercurrent Cascade Rinsing
10-56
-------
Drag-out
Drag-out
Plating
Tank
Recovery
Rinse
Drag-Out Solution
is Recirculated
to Electrowinning
Unit
City Water
Rinse
To Treatment
Scrap Metal
to Recycle
Electrowinning
Batch Dump
or Occasional
Purge to
Treatment
Figure 10-7. Electrolytic Recovery
10-57
-------
Deionized Water Recycled to Rinse
Drag-out ^
I Dra
Recovery 1
Plating Recovery
Tank Rinse
IX Regeneration
J-OUt
_. ., Acid NaOH
i ' T | || |
1 1 1
i i i
Recycle 1 1 1
Rinse JTiiTli tTli
..
s •§ 1 -I 1 I
3 o 8 3 § §
Rinse Water A 1 A 1 j A | 1 A
1 !
1
1
Acid/Metal 1 i
! L___L
Metal-Depleted
Electrolyte Reused •>
for DC Regeneration
or Contract Hauled
t V
Electrowinning
Duplex Cation
and Anion Columns
Wastewater
Discharged to
! Waste Treatment
Scrap Metal
to Recycle
Ion Exchange Recovery-Metal Recovery/Deionized Water Recycle
Evaporation
A
Drag-out
:ecovery
\*J/*3~^~<**
Drag-out
Plating
Tank
Recovery
Rinse
IX Regeneration
City Water
Rinse
Rinse Water
Metal-Depleted
Electrolyte Reused
for IX Regeneration
or Contract Hauled
Acid Acid
I 1 X
3 LJ, .L.
I I
Acid/Metal I '
Duplex Cation
Columns
Wastewater
Discharged to
Waste Treatment
Electrowinning
Scrap Metal
to Recycle
Ion Exchange Recovery-Metal Scavenging Configuration
Figure 10-8. Common Configurations for
Application of Ion Exchange for Chemical Recovery
10-58
-------
Drag-out Drag-out
Plating
Tank
Rinse Water
Feed Stream:
Ig/lTDS
Carbon
Filter
Rinse
Tank
Fresh Water
Drag-out
Rinse
Tank
RO Unit
Rinse
Tank
Fresh Water
To Waste Treatment
\
Reject (concentrate):
20g/lTDS
Permeate:
250 mg/1 TDS
Figure 10-9. In-Process Reverse Osmosis
10-59
-------
REDUCING AGENT
(SODIUM BOROHYDRIDE), OR PRECIPITANT (DITHIOCARBAMATE)
pH
METER
LIME OR
SODIUM
HYDROXIDE
o
o
CHELATED METAL-
BEARING WASTEWATER
FROM UNIT OPERATIONS
REACTION
TANK
MIXER
DE-CHELATED
METAL-BEARING
WASTEWATER
TO CHEMICAL
PRECIPITATION
AND SEDIMENTATION
Figure 10-10. Chemical Reduction of Chelated Metals
-------
REDUCING AGENT
(SULFUR DIOXIDE, SODIUM BISULFITE,
SODIUM METABISULFITE OR FERROUS SULFATE)
PH
METER
SULFURIC
ACID
OXIDATION-REDUCTION POTENTIAL
METER
^ MIXER
HEXAVALENT
9
ON
CHROMIUM-BEARING
WASTEWATER FROM
UNIT
OPERATIONS
REACTION
TANK
TRIVALENT CHROMIUM-
BEARING WASTEWATER
TO CHEMICAL PRECIPITATION
AND SEDIMENTATION
Figure 10-11. Chemical Reduction of Hexavalent Chromium
-------
ON
K)
SODIUM SODIUM
HYPOCHLORITE HYPOCHLORITE
pH
METER SODIUM
\HYDROXIDE
I 1
CYANIDE-BEARING
WASTEWATER FROM
UNIT OPERATIONS
OXIDATION-
REDUCTION
POTENTIAL pH
METER METER
/ /Q MIXER v AC|D
/ P \ I
t 4 ^
REACTION
TANK
CYANATE-BEARING
WASTEWATER
OXIDATION-
REDUCTION
POTENTIAL
METER
//O MIXER
r
t 4 ^
REACTION
TANK
TREATED
WASTEWATER TO
DISCHARGE OR
TO CHEMICAL
PRECIPITATION &
SEDIMENTATION
This technology may also be performed on a batch basis in a single tank.
Figure 10-12. Cyanide Destruction through Alkaline Chlorination
-------
EMULSION BREAKING / COAGULATION
CHEMICALS
(ACID, ALUMINUM SULFATE, FERRIC CHLORIDE, POLYMER)
MIXER
9
ON
U)
EMULSIFIED
OIL-BEARING
WASTEWATER
HOLDING
TANK
pH
METER
MIX
TANK
TO OIL SKIMMING
NON-EMULSIFIED
OIL-BEARING
WASTEWATER
Figure 10-13. Chemical Emulsion Breaking
-------
DIRECTION OF ROTATION
SCRAPER OR
SQUEEGEE
OIL CLINGS TO DRUM
DISK. BELT, OR TUBE
ROTATINQ DRUM,
DISK, BELT, OR TUBE
TO DISCHARGE
EFFLUENT^ OR TO
CHEMICAL
PRECIPITATION
&
SEDIMENTATION
WASTEWATER
FROM UNIT
OPERATIONS
BAFFLES
OIL REMOVAL -
TROUGH
TO CONTRACT HAUL
-WEIR
WEIR
OIL-BEARING
WASTEWATER
FROM UNIT
OPERATIONS
EFFLUENT
TO DISCHARGE
OR TO
CHEMICAL
PRECIPITATION
&
SEDIMENTATION
-EFFLUENT
TROUGH
Figure 10-14. Oil Skimming
10-64
-------
ON
PRECIPITATION
CHEMICALS *
PH
METER
\
METAL-BEARING
WASTEWATER FROM
UNIT OPERATIONS
/^ MIXER
MIX
TANK
CLARIFIER OR
SETTLING
TANK
TREATED
WASTEWATER TO
DISCHARGE
SLUDGE TO
DISPOSAL OR
FURTHER
DEWATERING
* PRECIPITATION CHEMICALS FOR HYDROXIDE PRECIPITATION INCLUDE: CALCIUM HYDROXIDE (LIME), SODIUM HYDROXIDE OR
MAGNESIUM HYDROXIDE.
PRECIPITATION CHEMICALS FOR SULFIDE PRECIPITATION INCLUDE: HYDROGEN SULFIDE, SODIUM SULFIDE OR
FERROUS SULFIDE.
PRECIPITATION CHEMICALS FOR CARBONATE PRECIPITATION INCLUDE: SODIUM CARBONATE (SODA ASH),
SODIUM BICARBONATE OR CALCIUM CARBONATE.
Figure 10-15. Chemical Precipitation and Sedimentation
-------
10-"
Figure 10-16. Effect of pH on Hydroxide Precipitaion
Source' Technical Development Document for the Organic Chemical, Plastics and Synthetic Fibers Point
Source Category, and the Technical Development Document for the Nonferrous Metal Forming
and Metal Powders Point Source Category.
10-66
-------
SLUDGE
FROM CHEMICAL
PRECIPITATION
APPROX. 3% SOLIDS
SUPERNATANT
4-
o
-J
SUPERNATANT
BACK TO CHEMICAL
PRECIPITATION
THICKENED SLUDGE
TO CONTRACT HAUL OR TO
SLUDGE DEWATERING
(APPROX. 5% SOLIDS)
Figure 10-17. Gravity Thickening
-------
PERFORATED
BACKING PLATE
FABRIC
FILTER MEDIUM
SOLID
RECTANGULAR
END PLATE
INLET SLUDGE
FROM CHEMICAL
PRECIPITATION
ENTRAPPED
SOLIDS
REMOVED
PERIODICALLY
TO CONTRACT
HAUL
PLATES AND FRAMES
ARE PRESSED TOGETHER
DURING FITLRATION
CYCLE
-RECTANGULAR
METAL FRAME
FILTERED LIQUID RETURNED
TO CHEMICAL PRECIPITATION
RECTANGULAR FRAME
Figure 10-18. Pressure Filtration
10-68
-------
DIRECTION OF ROTATION
FABRIC OR WIRE
FILTER MEDIA
STRETCHED OVER
REVOLVING DRUM
ROLLER
SLUDGE SOLIDS
SCRAPED OFF
FILTER
MEDIA
VACUUM
SOURCE
LIQUID FORCE
THROUGH
MEDIA BY
MEANS OF
VACUUM
SLUDGE SOLIDS
COLLECTION
HOPPER
TO CONTRACT HAUL
TROUGH
FILTERED LIQUID
RETURNED TO
CHEMICAL
PRECIPITATION
-•—INLET
LIQUID
TO BE
FILTERED
FROM
CHEMICAL
PRECIPITATION
Figure 10-19. Vacuum Filtration
10-69
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10.0 TECHNOLOGY OPTIONS
10.7 References
1. Facility Pollution Prevention Guide. EPA/600/R-92/088, U.S. EPA, Washington,
DC, 1992.
2. Development Document for Effluent Limitations Guidelines and Standards for
the Nonferrous Metals Forming and Metal Powders Point Source Category.
U.S. Environmental Protection Agency, EPA 440/1-86/019, September 1986.
3. Cherry, K.F Plating Waste Treatment. Ann Arbor Sciences Publishers, Inc., Ann
Arbor, Michigan, 1982.
4. Freeman, K.M. Standard Handbook of Hazardous Waste Treatment and
Disposal. McGraw Hill Book Company, New York, 1989.
10-70
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11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND
VARIABILITY FACTORS
This section summarizes the results of an assessment of the demonstrated performance
and the calculation of long-term average technology effectiveness concentrations for the
end-of-pipe wastewater treatment technologies described in Section 10.0. The
demonstrated performance for the following technologies is described below:
• Cyanide destruction through alkaline chlorination (for treatment of
cyanide);
• Chemical precipitation and sedimentation and preliminary
treatment, where appropriate, consisting of chemical emulsion
breaking, oil skimming, chromium reduction and chemical reduction
of chelated metals (for treatment of all other regulated pollutants).
Section 10.0 contains a detailed description of each of these technologies, as well as the
physical and chemical principles underlying their operation. Section 10.0 also identifies
the number of Metal Products and Machinery (MP&M) sites visited, DCP respondents,
and Phase I sites that use each of these technologies.
Section 11.1 describes the data sources used in assessing the performance of cyanide
destruction and chemical precipitation and sedimentation technologies; Section 11.2
describes the data editing procedures used in the assessment; and Section 11.3 describes
the long-term average concentrations, variability factors, and limitations calculated from
this assessment.
11.1 Sources of Technology Performance Data
EPA collected and compiled analytical data for treatment influent and effluent streams
for 23 chemical precipitation and sedimentation systems at 19 MP&M Phase I sites.
EPA also collected data for raw wastewater and treated wastewater for seven cyanide
destruction systems at seven MP&M Phase I sites. These data, collected using EPA
sampling and chemical analysis protocols as described in Section 4.0, are presented in
sampling episode reports contained in the administrative record for this rulemaking.
Sampling episodes ranged in duration from one to five days.
The database of sampling episode treatment influent and effluent data, termed the
Technology Effectiveness Concentration (TEC) database, contains 11,510 data points. A
data point is a concentration of a specific constituent in an influent or effluent stream
from a given sampling day at a sampled site. The TEC database contains cyanide data
for 49 cyanide destruction influent and effluent data points and 11,461 chemical
precipitation and sedimentation influent and effluent data points. Of these data points,
4,896 represent treatment of organic pollutants, while 6,565 represent treatment of
11-1
-------
11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
priority and nonconventional metal pollutants, and conventional and other
nonconventional pollutant parameters.
EPA did not calculate long-term average concentrations for organic pollutants. Although
organic pollutants are present in the wastewater generated by several specific MP&M
unit operations, they are rarely present in the combined wastewater treatment influent at
concentrations sufficient to assess treatment effectiveness. For this reason, the amount
of treatment effectiveness data collected during the MP&M sampling program for
organic pollutants is limited. As shown in Section 7.0, only 30 of the 233 organic
pollutants analyzed for in the MP&M sampling program were detected in wastewater
treatment influent streams and most of these were detected in one or two samples. The
primary mechanism of organic pollutant removal in the MP&M end-of-pipe technology
options is oil/water separation. For the MP&M Phase I regulation, oil and grease will
be used as an indicator parameter for the organic pollutants which have the potential to
be present and which will remain with the oil layer after oil/water separation. EPA
calculated long-term average technology effectiveness concentrations for organic
pollutants, for the purpose of estimating pollutant loadings and compliance costs;
however, these concentrations were not used in development of variability factors and
concentration limitations.
11.2 Data Editing Procedures
EPA reviewed the TEC database to identify data points that were considered
appropriate for calculating long-term averages and variability factors for the MP&M
industry. EPA identified data from well-designed and well-operated treatment systems,
and focused on data for the specific pollutants processed and treated on site.
Figure 11-1 summarizes the technology effectiveness data editing procedures discussed
below. As shown on this figure, the data editing procedures consisted of four major
steps:
(1) Assessment of the performance of the entire treatment system;
(2) Identification of process upsets during sampling that impacted the
treatment effectiveness of the system;
(3) Identification of pollutants not present in the raw wastewater at
sufficient concentrations to evaluate treatment effectiveness; and
(4) Identification of treatment chemicals used in the treatment system.
These steps are described below. Each data point that failed one or more of the
evaluation criteria described below was flagged and excluded from calculation of the
long-term average concentrations and variability factors. Only those data points that
were not assigned any of the flags described below were used to calculate long-term
11-2
-------
11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
averages and variability factors. The number of data points listed as receiving flags for
each editing criteria is additive (i.e., the numbers represent the number of data points
flagged for specifically that criteria).
11.2.1 Assessment of Treatment System Performance
The first step in the data editing procedures was to assess the performance of the entire
treatment system during sampling. For sites that were identified as not being well-
designed or well-operated systems, all data were flagged and excluded from use in
calculating long-term averages. For this assessment, EPA first identified the metals
processed on site, as well as whether the site performed unit operations likely to
generate oil and grease and cyanide. EPA focused on these pollutants because the
treatment trains described in Section 10.0 are designed to treat and remove these
pollutants. In some cases, complete data were not available as to the types of metals
processed on site because the EPA toured only a portion of the site during the visit. In
these cases, EPA reviewed the concentrations of pollutants in the raw wastewater to
identify additional pollutants likely processed on site. EPA then performed the following
four technical analyses of the treatment systems:
(1) EPA reviewed the sampled treatment systems to identify any
systems that included technologies not included in the technology
options listed in Section 10.0. If a sampled system included
technologies not in the technology options, the data from that
system could not be used to quantify the performance of any of the
technology options. EPA identified one system that included
biological treatment as part of the chemical precipitation and
sedimentation system. Because this technology was not included in
the technology options, EPA deleted the data from this system for
subsequent analysis by assigning a flag of "O" to all data from this
system (224 data points).
(2) Based on the metals processed or treated on site, EPA identified
chemical precipitation and sedimentation systems that were not
operated at the proper pH for optimal removal of the metals. This
analysis was performed on a system-by-system basis. Because the
optimum pH for metals removal by a system varies for each
combination of metals processed on site, control of pH is essential
for proper pollutant removal. EPA also reviewed data for cyanide
destruction systems to identify systems not operated at the proper
pH for cyanide destruction. EPA identified three chemical
precipitation and sedimentation systems that were operated outside
pH ranges considered to be optimum for removal of the metals
processed on site. EPA also identified one cyanide destruction
system that was operated outside the pH range considered optimum
11-3
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11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
for cyanide destruction. All data for these systems (904 data points)
were assigned a flag of "P".
(3) EPA identified chemical precipitation and sedimentation systems
that did not have solids removal indicative of effective treatment.
As discussed in Section 10.0, metals are removed in chemical
precipitation and sedimentation by sedimentation of metal
hydroxides in the form of suspended solids. The effectiveness of a
system at removing precipitated hydroxides is measured by the
removal of total suspended solids (TSS). Poor TSS removal is
typically indicative of poor metals removal. In general, EPA
identified solids removal systems that did not achieve 90% TSS
removal and had effluent TSS concentrations greater than 50 mg/L
as having poor solids removal. Site specific exceptions were made
to this rule depending on influent concentrations of TSS. Details on
these site-specific exceptions are contained in the MP&M public
record. EPA identified two systems that were considered to have
poor solids removal. All data for these systems (492 data points)
were assigned a flag of "T".
(4) EPA identified chemical precipitation and sedimentation systems at
which the concentration of most of the metals present in the
influent stream did not decrease. A lack of reduction in metal
concentrations is indicative of poor treatment. EPA identified two
systems for which most of the metals were not treated. All data for
these systems (296 data points) were assigned a flag of "A". EPA
did not identify any cyanide destruction systems across which the
concentration of cyanide did not decrease for most of the days
sampled.
11.2.2 Identification of Process Upsets Occurring During Sampling
EPA reviewed the sampling episode reports for each of the sampled sites, and identified
any process upsets that resulted in poor treatment during one or more days of the
sampling episode. EPA identified one system for which process upsets occurred during
sampling. For this system, the site personnel used barrel finishing wastewater
(containing iron and aluminum) as a flocculation agent. During two days of sampling,
site personnel used a different barrel finishing solution. This solution was not an
effective flocculation agent; therefore, the treatment system did not operate effectively
during these two days of sampling. The poor treatment is indicated by increased effluent
concentrations of metals during those two days as compared to the other days of
sampling. During the last day of sampling, site personnel discontinued use of the new
solution and used the original barrel finishing solution. All data points for samples
11-4
-------
11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
collected during the two days of sampling when the new solution was used (96 data
points) were assigned a flag of "V".
11.2.3 Identification of Pollutants Not Present in the Raw Wastewater at
Sufficient Concentrations to Evaluate Removal
As discussed above, the first step in assessing treatment performance consisted of
identifying the metals processed on site. This step included review of the concentrations
of pollutants in the raw wastewater to identify metals present that may not have been
identified during the site visit. EPA also identified sites processing oil and grease and
cyanide. Based on pollutants processed on site, as well as the treatment influent
concentrations of the pollutants analyzed, EPA performed the following data edits to
identify pollutants not present in the raw wastewater at sufficient concentrations to
evaluate removal.
(1) All data points for a pollutant at a site were assigned a flag of "N" if
the pollutant was not detected in any of the raw wastewater samples
collected during the sampling episode. EPA assigned this flag to
775 data points.
(2) All data points for a pollutant at a site were assigned a flag of "L" if
the pollutant was not detected in the raw wastewater at a
concentration greater than 0.1 mg/L in any of the raw wastewater
samples collected during the sampling episode. EPA assigned this
flag to 900 data points in addition to those previously flagged.
(3) All data points for a pollutant at a site were assigned a flag of "F" if
the pollutant was not detected in most of the raw wastewater
samples collected during the sampling episode. EPA assigned this
flag to 88 data points in addition to those previously flagged.
(4) All data points for a pollutant at a site were assigned a flag of "C" if
the pollutant was not detected in the raw wastewater at a
concentration greater than 0.1 mg/L in most of the raw wastewater
samples collected during the sampling episode. EPA assigned this
flag to 142 data points in addition to those previously flagged.
(5) If the raw material associated with a pollutant (metal, oil and
grease, or cyanide) was not processed on site, all of the remaining
records associated with that pollutant (those without flags) were
assigned a flag "1". EPA assigned this flag to 600 data points in
addition to those previously flagged.
11-5
-------
11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
EPA then reviewed the water use practices for the sampled sites to identify sites that
may be diluting the concentration in the raw wastewater of pollutants processed on site.
Because the MP&M effluent limitations guidelines and standards include water
conservation practices and pollution prevention technologies, EPA reviewed the data to
ensure that the technology effectiveness concentrations were based on sites that had
these practices and technologies in place. EPA reviewed the site visit reports, sampling
episode reports, and additional information obtained from each of the sampled sites to
identify unit operations for which sites did not have water conservation and pollution
prevention technologies in place, and assigned a flag of "2" to pollutants affected by poor
water use practices. EPA did not assign this flag to all pollutants on site because sites
could have poor water use practices for unit operation processing a specific pollutant
(e.g., a cadmium electroplating line) but could have good water use practices for all
other unit operations and pollutants processed on site. EPA assigned this flag to 100
data points in addition to those previously flagged.
11.2.4 Identification of Wastewater Treatment Chemicals
EPA identified wastewater treatment chemicals used in each of the sampled treatment
systems to determine if the removal of the metals used as treatment chemicals was
consistent with removal of other metals on site, indicating a well-designed and well-
operated system. If a metal was used as a treatment chemical, and the site treated the
metal to a concentration consistent with other metals removed on site, the treatment
chemical metal was not assigned a flag. If the metal was used as a treatment chemical,
and the metal was not removed to a concentration consistent with other metals removed
on site, but the metals processed on site were removed, the treatment chemical was
assigned a flag of "G". EPA assigned this flag to 194 data points in addition to those
previously flagged, primarily for calcium, sodium, and magnesium.
11.3 Long-Term Average Concentrations and Variability Factors
EPA used the data editing procedures described above to create the Long-Term Average
(LTA) database. EPA used this database to calculate the long-term average
concentrations and variability factors that are the basis for setting discharge limits. This
database included all data in the TEC database with the addition of the flags assigned
during data editing. This database contains 1,775 unflagged data points from
15 chemical precipitation systems, and 28 unflagged data points from four cyanide
destruction systems. Table 11-1 presents the unflagged data (i.e., the data from the TEC
database which was used to calculate long-term averages) for each of the regulated
parameters.
Long-term averages and variability factors were estimated from actual concentrations of
constituents measured in MP&M wastewaters treated by cyanide destruction and
chemical precipitation and sedimentation systems. The data sets of daily effluent
concentrations were obtained from EPA sampling episodes at MP&M facilities. For a
11-6
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11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
given sampling episode, long-term averages were determined for all analytes that had at
least one sample that passed engineering review, while variability factors were only
estimated for analytes that had at least four samples, including two detects.
The long-term average for each pollutant for a given sampling episode was estimated by
the arithmetic average of the daily concentration values. Observations recorded as below
the method detection limit (nondetects) were assigned a numerical value equal to the
detection limit. The daily variability factor was estimated for all constituents by fitting a
modified delta-lognormal distribution to daily concentration data. This is the same
distributional model used by EPA in the final rulemakings for the Organic Chemicals,
Plastics and Synthetic Fibers (OCPSF) and Pesticides Manufacturing categories and the
proposed rulemaking for the Pulp and Paper category.
The daily variability factor is defined as the estimated 99th percentile of the
concentration distribution divided by the expected value of the concentration. The 4-day
variability factor is defined similarly except that the 95th percentile of the distribution of
4-day averages is used instead of the 99th percentile of daily measurements. A
description of the modified delta-lognormal model is presented below.
11.3.1 Modified Delta-Lognormal Model
The modified delta-lognormal distribution models the effluent concentration data as a
mixture of nondetects and measured values. This distribution is appropriate because the
data for most constituents consisted of a mixture of measured values and nondetected
values. The modified delta-lognormal distribution assumes that each nondetect
observation represents an actual concentration equal to the method detection limit, and
the detected values are distributed according to a lognormal distribution.
The expected value, 99th percentile, and variability factor for the concentration of each
constituent were estimated by fitting the data to a delta-lognormal distribution (1),
modified to accommodate a non-zero value of the detection limit (2).
The modified delta-lognormal model is a mixture distribution in which the detected
concentrations follow a standard lognormal distribution (i.e., the logarithm of the
concentration is assumed to be normally distributed with parameters mean, /x, and
standard deviation, a). All nondetects are assumed to have a concentration value equal
to the detection limit.
The cumulative distribution function, which gives the probability that an observed
concentration (C) is less than or equal to some specified level (c), can be expressed as a
function of the following quantities:
D = the detection limit,
d = the probability of a nondetect,
11-7
-------
11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
I(c-D)
an indicator function which equals 1 for c > D and 0
otherwise,
the mean of the distribution of log transformed
concentrations,
the standard deviation of the distribution of log
transformed concentrations,
variable of integration.
The equation of the cumulative distribution function is as follows:
F(c) = P(C
-------
11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
The daily variability factors for each sampling episode-constituent data set were
estimated by the following steps (for notational purposes let a typical data set consist of
nj detects, n2 nondetects, and have concentrations Xj, i = l,..,n,). The estimate, £, of the
log mean was calculated by taking the arithmetic average of the log transformed detects:
(n-6)
The estimate, a, of the log standard deviation was calculated by taking the square root of
the sum of the squared differences between the log concentrations and /}, divided by the
number of detects minus one:
o =
n -1 U
The estimated probability of a nondetect, S, was calculated by dividing the number of
nondetects by the number of observations:
ni+n2
(11-8)
These quantities were then substituted into equations 11-2 and 11-4 to give estimates
E(C) and C99 of the mean concentration and the 99th percentile, respectively. Finally,
the resulting estimated mean and 99th percentile were substituted into equation 11-5 to
yield the daily variability factor estimate, VF(1).
The average daily variability factor multiplied by the median long-term average yields
the value used by EPA as the maximum value that an individual concentration
measurement can be expected to attain. An analogous measure of the maximum value
attained by the averages of four daily concentration measurements can also be defined
and estimated from the data. The definition of the 4-day variability factor, VF(4), is the
95th percentile of the distribution of 4-day averages, divided by the expected value of
4-day averages.
The value of VF(4) can be estimated from the daily concentration data by exploiting the
statistical properties of the 4-day averages, C4, and approximating the distribution of C4
by the modified delta-lognormal model. This approximation has been shown to provide
a good estimate to the actual distribution (3). To develop the estimate of VF(4), first
note that the logarithm of C4 is normally distributed with unknown mean and standard
deviation denoted by ju4 and cr4, respectively. Also, E(C4) = E(C) because the expected
11-9
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11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
value of a sum of random variables divided by a constant is equal to the sum of their
expectations divided by that constant. And V(C4) = V(C)/4 because the variance of a
sum of independent random variables divided by a constant is equal to the sum of their
variances divided by the square of that constant (4). Finally, the probability that C4 is a
nondetect is 54, since the average of four independent concentrations is a nondetect only
if all four are nondetects, and the probability of this occurring is equal to the product of
the component probabilities, or 54 if the daily nondetect probability is 5.
The following equations therefore hold:
E(C4) = E(C) = 54D + (1-54) exp
(11-9)
- (H-1C
and
C95(4) = max
D,exp
0.95-S4
(11-11)
Equations 11-9 and 11-10 can be algebraically solved for a4 in terms of the average and
variance of the daily concentrations, the probability of a nondetect, and the detection
limit. This expression is as follows:
04 = In
V(C) _ S4(1-64)D2 264D
4(E(C)-54D)2 (E(C)-54D)2 E(C)-54D
To derive an estimate, a4, of the left-hand side of equation (11-12), each quantity on the
right-hand side was replaced by its estimate computed from the daily concentration data
(i.e., E(C) was replaced by E(C), V(C) by V(C), and 6 by S). Next, the estimated a4
together with S and E(C) were substituted into equation 11-9, which was solved to yield
an estimate ju4 of ^4. Finally, /i4 and a4 in equation 11-11 were replaced by their
estimates to yield an estimated value of the 95th percentile of the 4-day average
distribution, and this estimate was divided by E(C) to give the estimated variability factor
VF(4).
11-10
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11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
The EPA sampling episodes provided a single detection limit for all analytes except for
oil and grease at one site. Because the modified delta-lognormal distribution is based on
a single detection limit, EPA had to select the detection limit to be used for the
statistical analyses in this case. EPA used the average oil and grease detection limit for
this site to estimate the variability factor. The variability factor results would not have
differed if an alternative detection limit was chosen because the two reported detection
limits were so close in magnitude, 0.290 mg/1 and 0.300 mg/1.
The results of applying the modified delta-lognormal model are shown in Table 11-2,
which give the estimated long-term averages and variability factors of constituent
concentrations for facilities using chemical precipitation and sedimentation treatment and
cyanide treatment. Note that variability factors were not estimated for facility data sets
that had fewer than four observations or for those with fewer than two detects.
11.3.2 Option Limitations and Long-Term Average
The previous section described how sampling episode-level variability factors (VFs) were
estimated from daily effluent concentration data using the modified delta-lognormal
model. This section describes how these episode-level VFs were used to calculate daily
and monthly average limitations for the MP&M technology options and regulated
pollutants. Because the limitations are based on final end-of-pipe treatment, only one
set of limitations are presented. All of the MP&M technology options include end-of-
pipe chemical precipitation and sedimentation. Options 1A, 2, 2A, and 3 also include
other technologies such as in-process and end-of-pipe recycling; however, these
technologies do not affect the treatment performance of chemical precipitation and
sedimentation.
The daily limitation and monthly average limitation for a given constituent was estimated
according to the following methodology:
• The long-term average (LTA) was estimated for each data set by
computing the arithmetic average of the constituent daily
concentrations. Observations below the sampling episode detection
limit were set equal to the detection limit for the purposes of this
calculation.
• The constituent LTA was defined to be the median of the episode-
level constituent LTAs.
• For those episode data sets that had at least four observations,
including two detected values, the modified delta-lognormal model
was used to estimate daily and 4-day average variability factors (VF)
as described above.
11-11
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11.0 DEVELOPMENT OF LONG-TERM AVERAGES AND VARIABILITY FACTORS
• The constituent daily VF was defined to be the average of the
episode-level daily VFs; the constituent 4-day average VF was
defined to be the average of the episode-level 4-day average VFs.
• The daily and monthly average limitations were calculated by
multiplying the constituent LTA by the daily and 4-day constituent
VFs, respectively.
Table 11-3 shows the results of applying this methodology to estimate long-term
averages, daily limitations, and monthly average limitations for chemical precipitation
and sedimentation and cyanide destruction, respectively.
11-12
-------
Table 11-1
MP&M Technology Effectiveness Data*
Episode
Influent Concentration
(mg/L)
Effluent Concentration
(rng/L)
ALUMINUM
1197A
4011
4278
4279
4310
4330
4415
4417
4417A
5.040
2.040
0.571
20.600
10.700
13.100
6.750
6.280
4.610
3.915
59.832
27.345
26.395
18.021
17.129
11.350
4.280
2.870
11.306
6.601
6.248
4.107
2.831
31.762
28.953
22.635
85.000
42.100
30.800
29.100
9.500
571.000
0.270
0.286
0.247
2.450
5.520
2.770
0.068
0.044
0.030
0.054
2.814
1.076
1.979
2.306
2.225
0.373
0.373
0.451
0.084
0.089
0.080
0.079
0.087
2.040
0.120
0.195
4.710
4.890
6.540
8.250
3.840
1.950
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
11-13
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Table 11-1 (Continued)
MP&M Technology Effectiveness Data*
Episode
Influent Concentration
(mg/L)
Effluent Concentration
(mg/L)
CADMIUM
4277
4279
18.900
5.270
3.420
2.930
0.903
7.730
7.639
2.636
2.437
1.431
0.230
0.219
0.202
0.140
0.078
0.190
0.086
0.176
0.211
0.022
CHROMIUM
1197 A
4011
4079
4278
4279
4310
28.700
1.400
0.027
7.040
2.720
1.890
5.540
4.400
0.200
17.000
13.600
13.100
10.850
22.559
11.269
10.352
9.668
7.609
1,350.000
89.300
88.400
1.230
0.656
0.027
0.726
0.756
1.130
1.820
0.456
0.635
0.020
0.007
0.007
0.033
0.364
0.508
0.834
0.576
0.180
1.770
4.650
0.395
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
11-14
-------
Table 11-1 (Continued)
MP&M Technology Effectiveness Data*
Episode
Influent Concentration
(mg/L)
Effluent Concentration
(mg/L)
CHROMIUM (Continued)
4330
4384
4415
4417
4417A
4438
4470
34.721
34.568
8.533
6.651
5.762
20.300
9.460
5.410
3.480
1.350
5.304
1.476
0.973
5.100
3.560
3.310
2.770
1.570
16.100
28.100
19.300
17.400
12.102
7.792
7.568
6.136
5.177
0.066
0.131
0.043
0.050
0.043
0.786
0.603
0.593
0.532
0.411
0.015
0.020
0.112
0.020
0.029
0.013
0.010
0.022
0.021
0.099
0.088
0.091
0.083
0.108
0.069
0.055
0.072
COPPER
4277
29.500
14.600
13.100
7.735
5.160
0.638
0.385
0.462
0.701
0.610
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
11-15
-------
Table 11-1 (Continued)
MP&M Technology Effectiveness Data*
Episode
Influent Concentration
(mg/L)
Effluent Concentration
(mg/L)
COPPER (Continued)
4278
4279
4417A
125.000
101.500
67.100
57.400
3.663
2.193
1.812
1.163
0.930
37.000
0.061
0.329
0.087
0.036
0.099
0.093
0.124
0.175
0.034
21.600
CYANIDE
4274
4279
4384
4460A
119.000
108.000
65.500
50.000
48.000
11.000
9.900
7.600
25.100
23.850
5.860
4.570
0.366
21.100
0.010
0.010
0.010
0.010
0.010
0.010
0.010
0.010
0.758
0.694
0.945
0.992
0.463
0.020
IRON
4079
4277
67.300
26.900
3.350
4.050
1.240
0.493
0.393
0.148
1.040
1.520
1.740
0.017
0.042
0.037
0.028
0.055
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
11-16
-------
Table 11-1 (Continued)
MP&M Technology Effectiveness Data*
Episode
Influent Concentration
(mg/L)
Effluent Concentration
(mg/L)
IRON (Continued)
4278
4279
4310
4384
4415
4417
4417A
4438
4470
3880.000
3630.000
3400.000
2950.000
44.601
39.440
21.875
18.324
13.301
40.050
19.000
1.700
25.800
20.200
18.300
10.200
3.260
39.697
36.902
34.694
7.690
3.270
2.260
1.960
0.633
222.000
29.300
9.700
7.350
486.040
219.910
184.210
175.830
171.510
4.380
1.060
1.430
10.300
1.198
0.629
0.337
1.325
0.774
2.220
8.890
3.100
1.730
1.600
1.170
1.420
1.320
1.410
0.069
0.154
0.022
0.039
0.032
0.023
0.030
0.225
0.450
0.380
0.448
3.281
3.167
3.259
3.076
4.116
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
11-17
-------
Table 11-1 (Continued)
MP&M Technology Effectiveness Data*
Episode
Influent Concentration
(mg/L)
Effluent Concentration
(mg/L)
NICKEL
4277
4278
4279
4417A
4438
4470
27.400
6.380
3.540
2.705
1.050
608.000
594.000
502.500
481.000
13.153
7.141
3.847
3.537
2.619
9.330
34.200
32.400
31.700
2.664
2.293
2.052
1.880
1.830
0.173
0.197
0.180
0.180
0.161
0.318
0.317
1.570
0.596
0.527
0.477
0.481
0.058
0.363
0.014
0.378
0.518
0.348
0.222
0.224
0.229
0.339
0.143
ZINC
4277
4278
3.480
2.640
1.335
0.925
0.801
13.700
12.600
11.100
10.400
0.022
0.015
0.047
0.042
0.013
0.011
0.022
0.011
0.027
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
11-18
-------
Table 11-1 (Continued)
MP&M Technology Effectiveness Data*
Episode
Influent Concentration
(mg/L)
Effluent Concentration
(mg/L)
ZINC (Continued)
4279
4415
4417
4417A
4470
100.470
93.671
44.988
40.330
34.259
3.012
2.303
1.923
142.000
66.100
45.900
19.900
4.550
1,540.000
66.404
53.126
51.031
50.732
44.231
2.866
1.229
0.263
3.528
2.059
0.541
0.070
0.058
0.150
0.213
0,173
0.212
0.078
1.620
1.351
1.793
1.181
0.986
1.593
OIL AND GREASE
4384
4470
4471
47.200
30.000
18.000
10.000
6.000
52.000
23.500
23.000
22.000
18.000
114.000
78.000
61.000
60.000
49.000
10.000
5.000
12.000
8.200
18.000
8.000
11.500
8.000
7.000
8.000
7.000
13.000
5.000
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
11-19
-------
Table 11-1 (Continued)
MP&M Technology Effectiveness Data*
Episode
Influent Concentration
(mg/L)
Effluent Concentration
(mg/L)
TOTAL SUSPENDED SOLIDS
1197A
4011
4079
4277
4278
4279
4330
4384
260.000
54.000
12.000
230.000
230.000
130.000
240.000
74.000
67.000
320.000
20.000
16.000
13.000
11.000
4,650.000
2,300.000
1,900.000
420.000
1,600.000
1,400.000
960.000
850.000
695.000
78.000
30.000
23.000
19.000
10.000
610.000
586.000
565.000
394.000
380.000
32.000
20.000
28.000
22.000
30.000
28.000
9.000
5.000
5.000
14.000
14.000
17.000
10.000
17.000
18.000
34.000
11.000
120.000
57.000
60.000
25.000
94.000
52.000
4.000
5.000
3.000
11.000
10.000
23.000
68.000
50.000
32.000
55.000
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
11-20
-------
Table 11-1 (Continued)
MP&M Technology Effectiveness Data*
Episode
Influent Concentration
(mg/L)
Effluent Concentration
(mg/L)
TOTAL SUSPENDED SOLIDS (Continued)
4415
4417
4417A
4438
4470
4471
130.607
119.036
77.141
430.000
70.000
32.000
22.000
4.000
72.000
410.000
11.000
10.000
1,300.000
640.000
530.000
445.000
320.000
100.000
40.000
36.000
6.000
1.000
1.000
1.000
12.000
10.000
7.000
4.000
2.000
27.000
7.000
5.000
8.000
22.000
14.500
10.000
32.000
10.000
11.000
18.000
48.000
36.000
Source: MP&M Technology Effectiveness Concentration Database.
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
11-21
-------
Table 11-2
Variability Factors and Long-Term Averages for
Chemical Precipitation and Sedimentation Treatment*
Pollutant
Aluminum
Cadmium
Chromium
EPA Sampling
Episode
1197 A
4011
4278
4279
4310
4330
4415
4417
4417A
4277
4279
1197A
4011
4079
4278
4279
4310
4330
4384
4415
4417
4417A
4438
4470
Long-Term Average
(mg/L)
0.27
3.58
0.05
2.08
0.40
0.08
0.79
5.65
1.95
0.17
0.14
0.64
0.87
0.97
0.02
0.49
2.27
0.07
0.59
0.05
0.02
0.02
0.09
0.08
Daily Variability
Factor
NC
NC
1.79
2.19
NC
1.13
NC
1.92
NC
2.58
5.78
NC
NC
NC
5.11
3.25
NC
2.66
1.68
NC
2.46
NC
NC
1.73
4-Day Variability
Factor
NC
NC
1.27
1.34
NC
1.04
NC
1.27
NC
1.43
2.14
NC
NC
NC
1.99
1.58
NC
1.45
1.21
NC
1.40
NC
NC
1.22
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
NC = Not calculated due to insufficient data.
11-22
-------
Table 11-2 (Continued)
Variability Factors and Long-Term Averages for
Chemical Precipitation and Sedimentation Treatment*
Pollutant
Copper
Iron
Nickel
EPA Sampling
Episode
4277
4278
4279
4417A
4079
4277
4278
4279
4310
4384
4415
4417
4417A
4438
4470
4277
4278
4279
4417A
4438
4470
Long-Term Average
(mg/L)
0.56
0.13
0.11
21.60
1.43
0.04
4.29
0.85
4.74
1.45
0.54
0.03
0.23
0.43
3.38
0.18
0.70
0.38
0.01
0.41
0.23
Daily Variability
Factor
1.73
5.76
3.44
NC
NC
2.56
6.60
3.09
NC
1.42
NC
1.69
NC
NC
1.30
1.18
4.36
5.68
NC
NC
1.94
4-Day Variability
Factor
1.22
2.13
1.63
NC
NC
1.43
2.33
1.55
NC
1.13
NC
1.21
NC
NC
1.10
1.06
1.83
2.12
NC
NC
1.28
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
NC = Not calculated due to insufficient data.
11-23
-------
Table 11-2 (Continued)
Variability Factors and Long-Term Averages for
Chemical Precipitation and Sedimentation Treatment*
Pollutant
Zinc
Oil and Grease
TSS
EPA Sampling
Episode
4277
4278
4279
4415
4417
4417A
4470
4384
4470
4471
1197A
4011
4079
4277
4278
4279
4330
4384
4415
4417
4417A
4438
4470
4471
Long-Term Average
(mg/L)
0.03
0.02
1.99
0.22
0.17
1.62
1.38
16.84
10.50
8.25
26.67
26.67
6.33
14.40
45.75
57.60
6.60
45.60
1.00
7.00
27.00
6.67
17.70
28.25
Daily Variability
Factor
3.29
1.84
6.54
NC
2.40
NC
1.69
5.23
2.27
2.32
NC
NC
NC
1.62
6.49
2.71
3.20
2.52
NC
3.11
NC
NC
2.87
3.78
4-Day Variability
Factor
1.59
1.35
2.31
NC
1.39
NC
1.21
2.02
1.36
1.37
NC
NC
NC
1.19
2.30
1.46
1.57
1.42
NC
1.60
NC
NC
1.50
1.70
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
NC = Not calculated due to insufficient data.
11-24
-------
Table 11-2 (Continued)
Variability Factors and Long-Term Averages for
Chemical Precipitation and Sedimentation Treatment*
Pollutant
Cyanide
EPA Sampling
Episode
4274
4279
4384
4460A
Long-Term Average
(mg/L)
0.01
0.01
0.77
0.02
Daily Variability
Factor
NC
NC
1.94
NC
4-Day Variability
Factor
NC
NC
1.27
NC
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
NC = Not calculated due to insufficient data.
11-25
-------
Table 11-3
Long-Term Averages and Limitations for
Chemical Precipitation and Sedimentation
(Cyanide Destruction for Cyanide)*
Pollutant
Aluminum
Cadmium
Chromium
Copper
Iron
Nickel
Zinc
Oil and Grease
TSS
Cyanide
Number
of Sites
(LTA)
9
2
13
4
11
6
7
3
14
4
Number
of Sites
(VF)
4
2
6
3
6
4
5
3
8
1
Median
LTA
(rng/l)
0.785
0.155
0.093
0.344
0.853
0.306
0.223
10.500
22.183
0.015
1-Day
Variability
Factor
1.756
4.183
2.814
3.644
2.778
3.290
3.151
3.276
3.288
1.937
4-Day
Variability
Factor
1.231
1.785
1.474
1.660
1.457
1.570
1.569
1.583
1.592
1.275
Daily
Limitation
(mg/1)
1.4
0.7
0.3
1.3
2.4
1.1
0.8
35.0
73.0
0.03
Monthly
Limitation
(mg/1)
1.0
0.3
0.2
0.6
1.3
0.5
0.4
17.0
36.0
0.02
Source: MP&M Technology Effectiveness Database.
LTA = Long Term Average.
VF = Variability factor.
*Not-detected pollutants are reported at the detection limit. In these cases, the detection limits were used to
calculate LTAs, variability factors, and limitations.
11-26
-------
TREATMENT EFFECTIVENESS CONCENTRATION
DATABASE
Contains treatment influent and effluent analytical
data from 23 sampling episodes.
Assessment of treatment system performance:
(1) Technology not included in MP&M technology
Options (Rag = O)
(2) Treatment system not operated at proper pH
for optimal metals removal (Rag = P)
(3) Treatment system had poor solids removal
(Rag = T)
(4) Treatment system did not remove most metals
processed on site (Flag = A)
Identification of process upsets occurring during sampling
(Rag = V)
Identification of pollutants not present in the
wastewater at sufficient concentrations to evaluate removal:
(1) Pollutant not detected in all (Rag = N) or most
(Rag = F) of raw wastewater samples from a site.
(2) Pollutant not detected at concentration greater than 0.1
mg/L in all (Rag = L) or most (Flag = C) of raw wastewa-
ter samples from a site.
(3) Metal type not processed on site (Rag = 1)
(4) Metal type not present in raw wastewater because of
potential dilution from poor water use practices (Rag = 2)
Identification of wastewater treatment chemicals (Rag = G)
LONG-TERM AVERAGE DATABASE
Contains treatment influent and effluent
analytical data from 23 sampling episodes, including flags
identified in preceding steps
Figure 11-1. Summary of Technology Performance
Data Editing Procedures
11-27
-------
11.4 References
1. Aitchison, J, and JAC Brown. 1957. The Lognormal Distribution. London:
Cambridge University Press, pp. 95-96.
2. This modification of the delta-lognormal distribution was used by EPA in
establishing limitations guidelines for the Organic Chemicals, Plastics, and
Synthetic Fibers point source category. The approach is therefore
sometimes called the "Organics method."
3. Barakat, R. 1976. Sums of Independent Lognormally Distributed Random
Variables. Journal of the Optical Society of America. 66:211-16.
4. Cramer, H. 1963. Mathematical Methods of Statistics. Princeton University
Press, pp. 173-180.
11-28
-------
12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
This section describes the methodology used to estimate the costs for implementing each
of the technology options under consideration for the Metal Products and Machinery
(MP&M) Phase I Category. The technologies considered for MP&M Phase I are
described in Section 10.0. Section 10.0 also describes the combination of these
technologies into options for in-process source reduction and recycling and end-of-pipe
wastewater treatment. The cost estimates, together with the pollutant reduction
estimates described in Section 13.0, provide a basis for evaluating the options. The cost
estimates also provide a basis for determining the economic impact of regulation on the
industry at different pollutant discharge levels. The results from assessing the economic
impact of regulation are found in the Economic Impact Analysis (EIA) for the MP&M
Phase I Rulemaking, The EIA is included in the administrative record for this
rulemaking.
EPA used the following approach for estimating compliance costs for the MP&M
Phase I industry.
• A probability sample of MP&M Phase I industry sites received data
collection portfolios (see Section 4.0). The data collection portfolio
(DCP) responses from these sites were the bases for the model sites
developed for costing.
• Field sampling data were analyzed to determine the pollutant
concentrations of untreated wastewater in the industry (see
Section 13.0).
• Candidate in-process source reduction and recycling and end-of-pipe
wastewater treatment technologies were identified, and appropriate
groups of technologies were compiled into technology options. The
technology options serve as the bases of compliance cost and
pollutant loading calculations (see Section 10.0).
• Field sampling data were analyzed to determine pollutant removal
performance of the selected technologies (see Section 11.0).
• Cost equations for capital and operating and maintenance (O&M)
costs were developed for each of the technologies (see Section 12.3).
• A computerized design and cost model (the MP&M Design and
Cost Model) was developed and used to calculate compliance costs
(presented in Section 12.1) and pollutant loadings (presented in
Section 13.0) for each option.
12-1
-------
12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
• Output from the design and cost model was used to calculate total
annualized costs, cost effectiveness values, and the economic impact
to the industry (presented in the EIA).
EPA estimated industry-wide costs for five technology options by estimating compliance
costs for technology trains at 396 model sites and then using statistically calculated
industry weighting factors to scale the results to the 10,601 water-discharging MP&M
Phase I sites. Section 12.1 presents a summary of the results of the costing effort.
Section 12.2 presents the methodology used to select and develop model sites.
Section 12.3 presents the methodology for estimating costs, including descriptions of the
components that define capital and annual costs, sources of cost data, standardization of
cost data, an overview of the design and cost model, and general assumptions used for
costing. Section 12.4 presents detailed descriptions of the design and costing
methodology for each in-process and end-of-pipe technology used in the options.
Tables 12-1 through 12-4 and Figures 12-1 through 12-3 are located at the end of this
section.
12.1 Summary of Costs
As discussed in Section 10.0, EPA identified several in-process and end-of-pipe
technologies applicable to MP&M wastewaters. The individual technologies were
combined into technology options. Figure 12-1 provides a graphical representation of
how the various technologies are combined into technology options. Based on the
technologies included in each option and the wastewaters generated at the MP&M
model sites, EPA used the MP&M Design and Cost Model to estimate compliance costs
for each of the options.
Table 12-1 presents capital and annual costs for both direct and indirect dischargers for
all five options. The total capital investment presented in Table 12-1 represents the
direct capital costs calculated by the design and cost model, plus the indirect capital costs
discussed in Section 12.3.1. The annual cost presented in Table 12-1 represents the
direct annual costs calculated by the model, plus the system annual cost of monitoring
discussed in Section 12.3.1. Discussion regarding other system annual costs (taxes,
insurance, and amortization) are included in the EIA.
12.2 Model Site Development
The Agency used a model site approach to estimate costs for the water-discharging sites
in the MP&M Phase I Category (10,601 sites) based on cost estimates for a statistically
selected subset of sites. EPA developed a model site from each DCP respondent that
met the criteria described below to account for the variability in processes and treatment
systems in place within the MP&M Phase I Category.
12-2
-------
12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
12.2.1 Site Selection
EPA selected a site as a model if the site met the following criteria:
• Generated revenue from an MP&M Phase I sector;
• Discharged wastewater (treated or untreated) to either a surface
water or publicly owned treatment works (POTW); and
• Supplied sufficient economic and technical DCP data required to
estimate compliance costs and assess cost effectiveness of the
MP&M Phase I technology options.
Based on these criteria, 396 DCP respondents were selected for model site development.
EPA used the data from each of these sites to develop 396 model sites. Survey weights
were used to project estimates from the model sites to the MP&M Phase I industry
population of 10,601 sites. Development of the survey weights and the statistical
methodology used to characterize the industry are presented in the "Database Summary
Report for the Metal Products and Machinery Mini Data Collection Portfolio" (MDCP
Database Report) and the "Database Summary Report for the Metal Products and
Machinery Data Collection Portfolio" (DCP Database Report), located in the
administrative record for this rulemaking.
12.2.2 Wastewater Stream Parameters
Based on the information provided by the sites in their DCP responses, follow-up letters,
and phone calls, EPA classified each process wastewater stream at each site by the type
of unit operation (e.g., machining, electroplating, acid treatment), base metal type (e.g.,
iron, aluminum, copper), and where appropriate, metal type applied. The following
additional DCP data were used to characterize process wastewater streams.
• Wastewater discharge flow rate. For each process wastewater
stream, the rate of process wastewater discharge, the rate of
wastewater generated during equipment cleanups, and the rate of
wastewater generated during tank cleanouts were summed to obtain
the total wastewater discharge flow rate from the unit operation.
For sites that did not report wastewater discharge data, wastewater
flow rates were modeled statistically using other data provided in
the site's DCP or by using data for similar unit operations reported
in other DCPs. The approach for this modeling is presented in the
DCP Database Report.
• Production rate. Depending on the unit operation production-
normalizing parameter (see Table 5-4), DCP responses for surface
12-3
-------
12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
area processed, mass of metal removed, or air flow rate were used
to determine the production rate through a unit operation. For sites
that did not report production data, production rates were modeled
statistically using other data provided in the site's DCP or by using
data for similar unit operations reported in other DCPs. The
approach for this modeling is presented in the DCP Database
Report.
Operating schedule. DCP responses for the hours per day (hpd)
and days per year (dpy) of each unit operation were used when
supplied by sites. For blank responses, the following procedure was
used:
The maximum hpd and dpy reported by the site for other
unit operations were used;
If all hpd and dpy responses at the unit operation level were
blank, the DCP response for wastewater treatment system
operating schedule was used; and
If all hpd and dpy responses at the unit operation level were
blank, and if the wastewater treatment system operating
schedule was blank, 8 hpd and 250 dpy were used.
Discharge destination. DCP responses were used to determine
whether each unit operation discharged process wastewater, and if
so, whether the wastewater was discharged to a surface water or
POTW. EPA also determined from the DCP responses whether the
wastewater was treated on site prior to discharge. Wastewaters that
were contract hauled off site, deep-well injected, or discharged to
septic systems were not included in the model. For sites that did
not report a discharge destination for some or all operations, the
destination was modeled based on other technical information
provided in the DCP (e.g., types of discharge permits, discharge
destination of other unit operations, process flow diagrams).
Tank volume. Tank volume, which is a design parameter for
countercurrent cascade rinsing and drag-out recovery rinsing, was
not specifically requested in the DCP. Therefore, for rinses that
were reported as being discharged in batches, a linear relationship
between volume of batch discharge and annual discharge flow rate
was established. Assuming a constant batch volume to tank volume
ratio, this relationship was used to estimate tank volumes for all
rinsing operations.
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12.2.3 Pollutant Concentrations
The concentration of each pollutant in each model site process wastewater stream was
estimated using field sampling data for wastewater discharged from the unit
operation/metal type combinations. The field sampling program is discussed in
Section 4.0. These data were used with DCP flow and production data to calculate the
concentrations. A more detailed description of these calculations is provided in
Section 13.0.
12.2.4 Technology in Place
The term "technology in place" refers to those technologies that the Agency considered
to be installed and operating at a model site in 1989. Technology in place was
accounted for in the costing and pollutant removal efforts to ensure that EPA accurately
assessed the baseline (1989) costs and pollutant loadings.
Data required to assess in-process technologies in place were not available in the DCPs.
The Agency assumed in-process technologies were in place if the model site process
wastewater stream had a production-normalized flow rate (PNF, volume of wastewater
per unit of production) below the PNF established by the Agency for that technology.
The median PNFs for each unit operation are presented in Section 5.0. For example, if
a machining wastewater stream had a PNF below the PNF established by the Agency for
centrifugation and pasteurization of machining coolant, then the Agency assumed that
the model site had a machining coolant regeneration system in place. The specific
production-normalized flow rates established by the Agency for each technology are
discussed under the descriptions of each technology in Section 12.4.
EPA reviewed DCP data for each model site to assess the types of end-of-pipe
technologies in place at each site (e.g., chemical reduction of chromium, sludge pressure
filtration). Based on the DCP database, the number of sites having each of these end-of-
pipe technologies in place is presented in Table 12-2. EPA identified end-of-pipe
technologies on site that, based on technical considerations, were considered equivalent
to technologies included in the MP&M Phase I technology options. For example,
vacuum filtration was considered equivalent to pressure filtration for sludge dewatering.
EPA also identified technologies that were not considered equivalent, and for which no
credit for technology in place was given. For example, oil skimming not preceded by
chemical emulsion breaking was not considered equivalent to the oil/water separation
included in the technology options. Site-specific assumptions regarding treatment
technologies in place at model sites are included in the administrative record for this
rulemaking.
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EPA used the following additional DCP data to assess the capacity of the end-of-pipe
technologies in place at the model sites.
• Operating schedule. DCP responses for the hours per day (hpd)
and days per year (dpy) of operation of each treatment unit were
used when supplied by sites. For blank responses, the schedule was
determined using the following procedure:
The maximum hpd and dpy reported by the site for other
treatment units were used;
If all hpd and dpy responses for treatment units were blank,
the maximum hpd and dpy reported for the unit operations
were used; and
If the operating schedules for all treatment units and unit
operations were blank, 8 hpd and 250 dpy were used.
• Wastewater streams treated. The unit operation wastewater streams
treated by each end-of-pipe technology in place were determined
using the following procedure:
DCP process flow diagrams or responses to DCP questions
regarding the destination of individual process wastewater
streams were used; and
If information provided in the DCP was insufficient, then the
logic used by the model for assigning streams to technologies
was used (e.g., cyanide-bearing streams were directed to
cyanide destruction). This logic is described in Section 12.3.
EPA assumed that each model site operated the end-of-pipe technologies in place at full
capacity at baseline. Therefore, EPA used the operating schedule of the technology and
the wastewater streams treated by the technology to define the maximum operating
capacity for each technology. Assumptions regarding how the model accounted for end-
of-pipe technologies with insufficient capacity are presented in Section 12.3.4.
12.3 Methodology for Estimating Costs
This section presents a detailed discussion of the methodology for estimating costs, and
includes discussions of the components of cost, the sources of cost data, the
standardization of cost data, the design and cost model used, and the general
assumptions made during the costing effort.
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12.3.1 Components of Cost
The components of the capital and annual costs and the terminology used in developing
these costs are presented below.
Capital Costs
The capital costs consist of two major components: direct capital costs and indirect
capital costs. The direct capital costs include:
• Purchased equipment cost;
• Delivery cost (based on shipping distance of 500 miles); and
• Installation cost (including labor, excavation, site work, and
materials).
The direct components of the total capital cost are derived separately for each treatment
unit, or technology. Each treatment unit cost includes individual equipment costs (e.g.,
pumps, tanks, feed systems). The correlation equations used to generate the individual
equipment costs are presented in Table 12-3.
Indirect capital costs consist of secondary containment, engineering, contingency, and
contractor fees. When combined with the direct capital costs, these form the total
capital investment. The indirect costs are derived from factored estimates (i.e., they are
estimated as percentages of the total direct capital cost), as shown in Table 12-4.
Annual Costs
The annual costs also consist of both a direct and an indirect component. The equations
used to calculate individual equipment direct annual costs are presented in Table 12-3
and include the following.
• Raw materials. These costs are for chemicals and other materials
used in the treatment processes (e.g., calcium hydroxide, sulfuric
acid, sodium hypochlorite, ion-exchange resins).
• Operating labor and materials. These costs account for the labor
and materials directly associated with operation of the process
equipment.
• Maintenance labor and materials. These costs account for the
labor and materials required for repair and routine maintenance of
the equipment.
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• Energy. These costs are calculated based on total energy
requirements (in kW-hrs).
Indirect annual costs include monitoring, taxes, insurance, and amortization. Monitoring
refers to the periodic analysis of wastewater effluent samples to ensure that discharge
limitations are being met. Assumptions regarding monitoring frequency are presented in
Section 12.3.4. Discussions regarding taxes, insurance, and amortization are presented in
the EIA.
12.3.2 Sources and Standardization of Cost Data
Capital and annual cost data for the selected technologies were obtained from
equipment vendors, literature, and from existing MP&M sites. Specific data from the
DCPs were used whenever possible; however, the required types of data were often
either not collected or not supplied by the sites. The major sources of equipment cost
data were equipment vendors, while the majority of annual cost information was
obtained from the literature.
Capital and annual cost data were standardized to 1989 dollars (the year for which all
DCP data were collected) based on the following:
• Capital investment. Investment costs were adjusted using the
Chemical Engineering Plant Cost Index as published in Chemical
Engineering Magazine. The value of this index for 1989 was 359.4.
• Chemicals. The Chemical Marketing Reporter from July 24, 1989
was used to obtain chemical prices.
• Water. Water prices were based on the 1992 Rate Survey of Water
and Wastewater conducted by Ernst and Young. Data for 1989
were not available from this source; therefore, the water rate was
adjusted to 1989 using the capital investment index from above.
The cost for water used was $2.88 per 1,000 gallons of water.
• Energy. Monthly electricity prices for 1989 were averaged from the
U.S. Department of Energy's Monthly Energy Review. The
averaged values were the retail electricity prices charged for
industrial service by selected Class A privately-owned utilities. The
1989 monthly average value was $0.047 per kW-hr.
• Labor. A labor rate of $24 per hour was used to convert the labor
requirements of each technology into annual costs. The base labor
rate was obtained from the Monthly Labor Review, which is
published by the U.S. Bureau of Labor Statistics of the U.S.
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Department of Labor. Monthly values for 1989 for production labor
in the fabricated metals industry were averaged to obtain a base
labor rate of $10.50 per hour. Fifteen percent of the base labor rate
was added for supervision and 100 percent was added for overhead
to obtain the labor rate value of $24 per hour.
• Monitoring. The annual cost of monitoring was based on 1989
records for wastewater analyses kept by EPA's Engineering and
Analysis Division. These costs were as follows: metal pollutants,
$232; total cyanide, $35; oil and grease, $45; and total suspended
solids, $10.
• Contract hauling. Contract hauling costs were based on vendor
data obtained during 1993 or from data obtained during engineering
site visits performed from 1990 through 1992. The capital cost index
discussed above was applied to adjust the data to 1989 dollars. The
cost to contract haul metal-bearing sludge was averaged from data
obtained from four engineering site visits and two vendor quotes to
equal $2.90 per gallon. For waste oil, data from two engineering
site visits and two vendor quotes were averaged to equal $2.06 per
gallon. For paint sludge, data from two engineering site visits and
two vendor quotes were averaged to equal $3.72 per gallon. A
vendor quote for hexavalent chromium-bearing, cyanide-bearing, and
metal-bearing wastewater was used at prices of $0.49, $0.74, and
$0.49 per gallon, respectively. For wastewater bearing oil and
grease and organic pollutants, data obtained from EPA's Centralized
Waste Treaters project was used for a price of $1.05 per gallon.
12.3.3 Design and Cost Model
EPA developed a computerized design and cost model to estimate compliance costs and
pollutant loadings for the MP&M technology options, taking into account each site's
treatment in place. The model was programmed with modules which allowed the user to
specify various combinations of technologies and practices to be costed as required by
the technology options and each model site's wastewater stream characteristics. In the
context of the MP&M cost program, "model" refers to the overall computer program
and "module" refers to a computer subroutine which generates costs and pollutant
loadings for a specific in-process or end-of-pipe technology or practice (e.g., chemical
precipitation and sedimentation, contract hauling). Some modules were adapted from
cost models used for previous EPA rulemaking efforts for the metals industry, while
others were developed specifically for this rulemaking effort.
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The Agency developed cost modules for the in-process source reduction and recycling,
and end-of-pipe wastewater treatment technologies and practices included in the MP&M
Phase I technology options. These technologies and practices are shown below.
Technologies and Practices for Which Cost Modules Were Developed
In-Process Technologies and Practices
End-Of-Pipe Technologies and Practices
Flow reduction for rinses
Flow reduction for other operations
Countercurrent cascade rinsing
Centrifugation and pasteurization of machining
coolants
Centrifugation of painting water curtains
In-process ion exchange and electrolytic recovery
Oil/water separation
Chemical reduction of hexavalent chromium
Cyanide destruction
Chemical reduction of chelated metals
Contract hauling of solvent degreasing wastewaters
Chemical precipitation and sedimentation
Sludge thickening
Sludge pressure filtration
End-of-pipe ion exchange
Source: MP&M DCPs, MP&M site visits, technical literature.
As described in Section 10.0 and shown in Figure 12-1, Option 1 consists of the end-of-
pipe technologies and practices shown above except end-of-pipe ion exchange. Option 2
includes all of the technologies and practices in Option 1 plus all of the in-process
technologies and practices. Option 3 includes all of the technologies and practices listed
above. Option 1A, considered only for indirect dischargers, consists of Option 1
technologies and practices for sites with discharge flow rates below one million gallons
per year and Option 2 technologies and practices for the remaining sites. Option 2A,
also considered only for indirect dischargers, exempts sites with discharge flow rates
below one million gallons per year and includes Option 2 technologies and practices for
the remaining sites. Each technology is discussed in Section 10.0, and specific details
regarding the design and costing of each technology and practice are described in
Section 12.4.
The logic used by the design and cost model to apply the in-process technologies and
practices (Options 1A, 2A, 2, and 3) to a model site is shown in Figure 12-2. As
described in Section 12.2.4, the technology-specific PNFs established by the Agency and
the unit operation-specific PNFs were used to determine if an in-process technology was
in place at a model site. Technology-specific PNFs were expressed in terms of the
median PNF. For example, a technology or practice may have been assumed to achieve
the median PNF, ten times the median PNF, or 10% of the median PNF, based on data
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from the DCPs, site visits, and technical literature. The unit operation-specific PNFs are
based on data reported in the DCPs. Technology-specific PNFs are summarized below:
• Flow reduction for rinses (e.g., flow restrictors, conductivity sensors,
timed rinsing) was assumed to reduce flow to ten times the median
PNF for a unit operation.
• Countercurrent cascade rinsing was assumed to reduce flow to the
median PNF.
• Flow reduction for other operations (e.g., manual control of
wastewater discharge rate or analytical testing and maintenance of
bath chemistry) was assumed to reduce flow to the median PNF.
• Centrifugation and pasteurization of machining coolants were
assumed to reduce flow to 20% of the median PNF, since these
recycling steps allow the coolant to be used for a longer period of
time.
• In-process ion exchange was assumed to reduce flow to 10% of the
median PNF. The rinse water recirculates through the ion-exchange
column for metals removal, and back to the rinse. The discharge
represents a rinse water bleed stream and a column regeneration
stream.
• Centrifugation of painting water curtains was assumed to achieve
zero discharge of wastewater (with contract hauling of sludge
removed from the centrifuge) through 100% reuse of the treated
wastewater in the painting booth.
The Agency assumed that sites with PNFs below the target PNFs mentioned above had
these technologies in place. These technology-specific PNFs are consistent with data
obtained from equipment vendors, literature, DCPs, and engineering site visits.
For flow reduction of rinses, flow reduction of other operations, countercurrent cascade
rinsing, and in-process ion exchange, EPA estimated costs for individual units for each
process wastewater stream at a site (e.g., five separate countercurrent cascade rinsing
systems were costed for five separate acid treatment rinses at the same model site). For
Centrifugation and pasteurization of machining coolants and Centrifugation of painting
water curtains, the process wastewater streams were modeled as being combined prior to
application of the technology.
Figure 12-3 presents the logic used by the design and cost model to apply the end-of-pipe
treatment technologies and practices (all options). Wastewater streams from the unit
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operations and the in-process technologies (when applicable) were segregated based on
pollutant characteristics (chromium, cyanide, chelated metals, oil, and solvent). Solvent-
bearing wastewater streams were contract hauled for off-site disposal, while the other
segregated wastewater streams received preliminary treatment.
Effluent from the preliminary treatment technologies was combined with other
wastewater streams not requiring preliminary treatment, then treated by chemical
precipitation and sedimentation. Sludge from the clarifier of the chemical precipitation
and sedimentation system underwent sludge thickening and pressure filtration prior to
contract hauling for off-site disposal. For Option 3, effluent from the chemical
precipitation and sedimentation system was polished using end-of-pipe ion exchange.
Ninety percent of the effluent was reused on site; the remaining 10% was discharged to a
surface water or POTW. For Options 1, 1A, 2A, and 2, the effluent from the chemical
precipitation and sedimentation system was discharged to either a surface water or
POTW.
The model provided the following types of information, as applicable, for each
technology designed for a model site:
• Total direct capital costs;
• Total direct annual costs;
• Electricity used and associated cost;
• Sludge generation and associated disposal costs;
• Waste oil generation and associated disposal costs;
• Water use reduction and associated cost credit;
• Metal reclaimed and associated cost credit;
• Chemical usage reduction and associated cost credit;
• Effluent flow rate; and
• Effluent pollutant concentrations.
Specific information calculated by each technology module is presented in Section 12.4.
12.3.4 General Assumptions
This section presents general assumptions that were applied throughout the design and
cost model. Technology-specific assumptions regarding the design and costing of the
technologies are presented under the appropriate technologies in Section 12.4.
Calculation of Baseline Parameters
As discussed in Section 12.2.4, EPA determined the technologies already in place,
including the operating schedules of these systems and the wastewater streams treated by
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these systems. Before running the cost model for any of the technology options, a
baseline run of the model was performed to determine the following:
• Baseline (1989) operating and maintenance costs incurred by sites;
• Baseline nonwater quality impacts such as electricity usage, sludge
generation, and waste oil generation;
• Baseline pollutant loadings; and
• Capacity flow rate of each technology in place.
Use of the capacity flow rate is discussed below. The baseline values for operating and
maintenance costs, nonwater quality impacts, and pollutant loadings were subtracted
from the values calculated from each technology option to determine the incremental
impact over the baseline for each technology option.
End-of-Pipe Technology in Place
As discussed in Section 12.2.4, the model was designed to account for in-process and
end-of-pipe operating equipment already in place at the model sites. The assessment of
in-process technologies in place is discussed in Section 12.3.3. For end-of-pipe treatment
technologies, EPA reviewed information in the DCPs to assess the level of treatment in
place at MP&M Phase I sites. EPA identified which of the technologies included in
each of the options were in place at the sites. Some sites had no technologies in place,
some had a portion of the options in place, and others had complete treatment in place.
EPA also assessed the design capacity flow for each treatment unit in place to determine
whether each site had sufficient capacity to treat all MP&M process wastewater. In
some cases, the technology options required a model site to treat additional wastewater
streams with a technology in place at baseline. In these situations, the treatment
capacity of the technology may have been insufficient. The following assumptions were
used regarding end-of-pipe technology capacities:
• If the technology did not exist at the model site, then a treatment
unit of sufficient capacity was designed;
• If the technology existed at the model site with sufficient capacity to
treat all of the wastewater, then no treatment unit was designed;
and
• If the technology existed at the model site but with insufficient
capacity to treat all of the wastewater, then the existing system was
assumed to operate at full capacity and an additional treatment unit
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was designed to operate in parallel with the existing unit to treat the
additional flow.
Precious Metal Reclamation in Place
Based on observations on engineering site visits, EPA assumed that sites generating
wastewaters with high concentrations of gold or silver were reclaiming these metals at
baseline, either on site or off site. Silver was the only precious metal that was an
MP&M pollutant of concern. For the purposes of calculating costs and pollutant
loadings, it was assumed that at baseline, all silver electroplating baths and silver
electroplating rinses were segregated and that silver was recovered prior to discharge.
Contract Hauling in Lieu of Treatment
EPA assessed the cost of contract hauling wastewater for off-site treatment compared to
on-site treatment. The equipment used for the MP&M Phase I technology options has
minimum sizes. Because many MP&M sites have low flow rates, it was often found to
be less expensive for a model site to have wastewater contract hauled for off-site disposal
rather than to treat the wastewater on site. To assess contract hauling in lieu of
treatment, EPA compared the costs of contract hauling the wastewater to be treated in a
specific treatment unit with the costs of the treatment unit. If contract hauling was less
expensive than treating on site, the site was modeled as contract hauling the wastewater.
This determination was based on individual technologies and their influent characteristics
(flow rate, pollutant concentrations) rather than on the total site wastewater treatment
system. For example, cyanide-bearing wastewater could be contract hauled in lieu of
treatment while all other wastewater streams were treated on site. The calculation for
determining whether treatment on site was less expensive included an equipment life
expectancy of 15 years and an annual interest rate of 7 percent.
The following technologies were considered for contract hauling in lieu of treatment:
• Centrifugation and pasteurization of machining coolants;
• Centrifugation of painting water curtains;
• In-process ion exchange;
• Oil/water separation;
• Chemical reduction of hexavalent chromium;
• Cyanide destruction;
• Chemical reduction of chelated metals;
• Chemical precipitation and sedimentation;
• Sludge pressure filtration; and
• End-of-pipe ion exchange.
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In the case of end-of-pipe ion exchange, the assessment of treating versus contract
hauling was made by comparing the costs of contract hauling the untreated end-of-pipe
wastewater to the cost of the entire end-of-pipe wastewater treatment system.
Equipment Size Ranges
As shown in Table 12-3, equipment cost equations were developed for each component
of the technologies. The validity ranges presented in the table represent the minimum
and maximum sizes (e.g., flow rates, volume capacities) for which the equations were
developed. For wastewater streams requiring equipment with a capacity below the
minimum range of validity, the equipment was designed at the minimum size. For
wastewater streams requiring equipment with a capacity above the maximum range of
validity, multiple units of equal capacity were designed to operate in parallel such that
the equipment sizes were within the range of validity.
Batch Schedules
For many of the end-of-pipe technologies, EPA designed either batch or continuous
systems, depending on the site operating schedule and discharge flow rate. For batch
systems, the batch volume and operating schedule were established to minimize cost. If
the volume of wastewater to be treated in a single day was below the minimum batch
system size, then the operating schedule was altered such that a minimum system would
be operated at capacity. For example, if the minimum cyanide destruction system was 60
gallons per batch, and a site generated 10 gallons of cyanide-bearing wastewater per day,
then a cyanide destruction system was designed to treat a 60-gallon batch once every six
days.
Monitoring
Monitoring costs are presented in Section 12.3.2. The following assumptions were made
regarding the frequency of monitoring required by site discharge permits and the
monitoring costs currently incurred by sites at baseline.
• Metals and cyanide analyses were assumed to be required four times
per month for both direct and indirect dischargers;
• Total suspended solids and oil and grease analyses were assumed to
be required four times per month for direct dischargers; and
• Sites reporting in their DCP as currently having a National Pollutant
Discharge Elimination System (NPDES) permit or to be currently
regulated by categorical effluent limitations guidelines and standards
were assumed to have a monitoring program in place. The in-place
programs were assumed to have all of the above parameters
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monitored once per year for direct dischargers and twice per year
for indirect dischargers.
Dilute Influent Concentrations
High wastewater flow rates combined with low production rates caused pollutant
concentrations at some sites to be modeled below the long-term average technology
effectiveness concentrations (discussed in Section 11.0). This primarily occurred at
Option 1, which does not include any flow reduction technologies. In these cases, the
model did not design a technology for that wastewater stream. When this situation
occurred during the baseline run of the model, the technologies were designed based on
hydraulic load to calculate capacity flow rates and baseline operating and maintenance
costs for equipment modeled as in place.
Discharge Status
Some model sites have both direct and indirect discharging wastewater streams at
baseline. Because the technology options combine all wastewater streams prior to
chemical precipitation and sedimentation, a single discharge destination was assigned to
each model site. The following assumptions were used to assign discharge destinations
to model sites with both direct and indirect baseline discharges:
• If the model site had a wastewater treatment system at baseline with
the effluent discharged to one destination, while other wastewater
streams on site by-passed the treatment system and discharged to a
different destination, the destination of the wastewater treatment
system effluent was assigned to the site for the technology options;
and
• If the model site did not have technologies in place, the discharge
destination with the greatest baseline hydraulic load from the model
site was assigned for the technology options.
12.4 Design and Costs of Individual Technologies
The following are detailed discussions regarding the design and costing of the individual
technologies that comprise the technology options. Additional documentation is included
in the administrative record for this rulemaking. Capital and annual cost equations for
the specific equipment mentioned in each section are presented in Table 12-3.
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12.4.1 Flow Reduction for Rinses
The Agency applied flow reduction for rinses to those rinses identified through the DCPs
and site visits as typically being flowing rinses (e.g., not stagnant rinses). Rinsing
operations that did not receive this technology received flow reduction for other
operations (discussed below). The rinsing operations that did not receive flow reduction
for rinses are as follows:
• Abrasive blasting rinse;
• Abrasive jet machining rinse;
• Burnishing rinse;
• Calibration rinse;
• Disassembly rinse;
• Electrical discharge machining rinse;
• Floor cleaning rinse;
• Grinding rinse;
• Hot dip coating rinse;
• Impact deformation rinse;
• Machining rinse;
• Painting rinse (excluding electrophorectic);
• Polishing rinse;
• Pressure deformation rinse;
• Soldering rinse; and
• Sputtering rinse.
All other rinsing operations received flow reduction for rinses. EPA identified several
different technologies capable of reducing the discharge from a flowing rinse. EPA
investigated the following three flow reduction technologies: rinse timers to shut off the
discharge after a part has been rinsed and rinse water is no longer needed; flow
restrictors to provide a maximum flow rate into a rinsing operation; and conductivity
sensors to indicate pollutant contamination in the rinse and control the rinse discharge
based on contamination. Although sites may use any of these three technologies (as well
as others), the Agency based the annual and capital cost on automatic rinse timers
(including solenoid valves and electronic timers with associated switches and wiring),
which were estimated to be the most expensive of these technologies.
The direct annual costs for this module included operating and maintenance labor and
materials and a credit for water use reduction. Labor costs associated with this module
include one hour per year for maintenance. EPA calculated the water use reduction
achieved by this module using the unit operation-specific PNF reported by the site. For
the purpose of estimating compliance costs for the MP&M technology options, the
Agency assumed that flow reduction technologies could be used to reduce the discharge
from flowing rinses to ten times the median PNF reported in the DCPs for the unit
operations. If the PNF was below ten times the median PNF reported for the unit
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operation in the DCPs, EPA assumed that adequate rinse flow reduction technology was
in place and the module was not used. EPA made this assumption because information
on which sites had flow reduction technologies in place was not obtained in the DCPs.
For unit operations for which this module was applied, the wastewater flow rate was
reduced such that the PNF was equal to ten times the median PNF reported in the
DCPs, and pollutant concentrations were increased accordingly.
12.4.2 Flow Reduction for Other Operations
The Agency applied flow reduction for other operations to all unit operations not
considered for the rinse flow reduction module. The technology was based on the
assumption that the median PNF reported in the DCPs for each unit operation could be
achieved for each model site unit operation through manual control of the wastewater
discharge rate or through analytical testing and maintenance of bath chemistry. In cases
where the site-specific PNF was less than the median PNF for a unit operation, EPA
assumed that the site had flow reduction in place for the unit operation. In this case, the
module was not used. The Agency selected the median PNF, based on information from
site visits. For operations for which this module was applied, the wastewater flow rate
was reduced such that the unit operation-specific PNF was equal to the median PNF
reported in the DCPs, and pollutant concentrations were adjusted accordingly.
Capital costs for this module were assumed to be zero, since all equipment necessary for
process bath maintenance (e.g., thermometers, pH meters, test kits) are typically in place
at MP&M sites. Direct annual costs for this module included operating and
maintenance labor and materials and a credit for water use reduction. Labor costs were
calculated based on one hour per week of maintenance labor per each individual unit
maintained. A cost credit for water use savings was calculated based on the annual flow
reduction for each unit operation maintained.
12.4.3 Countercurrent Cascade Rinsing
The Agency applied countercurrent cascade rinsing to the same set of unit operations
considered for flow reduction of rinses. The technology was based on the installation of
an additional air-agitated rinsing stage to the existing rinse tank(s). Capital and annual
costs for the following equipment were included within the countercurrent cascade rinse
system:
• A rinse tank with a volume equal to the volume of the existing tank;
• An air-agitation system consisting of perforated polyvinyl chloride
(PVC) piping (air diffusers) and a motorized air blower; and
• A pump to transfer rinse water from one stage to the next.
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EPA estimated retrofit capital costs for installation of the above equipment as 15% of
installed equipments costs. These costs were included to account for costs incurred for
installation of an additional tank on an existing process line.
For the purpose of estimating compliance costs for the MP&M technology options, the
Agency assumed that countercurrent cascade rinsing could be used to reduce the
discharge from flowing rinses to the median PNF reported in the DCPs for the unit
operations. Information on which sites had countercurrent cascade rinses in place was
not available in the DCPs. EPA selected the median PNF based on information
collected during visits to MP&M Phase I sites.
The water use reduction after installation of the additional rinsing stage was calculated
based on the unit operation-specific PNF reported by the site. If the unit operation-
specific PNF was below the median PNF reported in the DCPs for the unit operation,
then the technology was assumed to be in place and the module was not used. For
operations for which this module was applied, the wastewater flow rate was reduced such
that the PNF was equal to the median PNF reported in the DCPs, and pollutant
concentrations were increased accordingly.
Direct annual costs for this module included operating and maintenance labor and
materials, energy costs, and a credit for water use reduction. The cost credit for water
use savings was based on the annual flow reduction for each countercurrent cascade
rinse system.
12.4.4 Centrifugation and Pasteurization of Machining Coolant
Centrifugation and pasteurization of machining coolant was applied to machining
operations discharging water-soluble or emulsified coolant. The system considered to
develop compliance cost estimates consisted of a liquid-liquid separation centrifuge for
removal of solids and tramp oils, and a pasteurization unit to stem microbial growth.
Fifty percent excess capacity was included when sizing each site's system to account for
fluctuations in production. Capital and annual costs were based on packaged systems of
different capacities. The various size systems included the following equipment:
• A high speed, liquid-liquid separation centrifuge;
• A pasteurization unit; and
• One holding tank (two holding tanks for the largest size system).
Direct annual costs included operating and maintenance labor and materials, energy
costs, sludge and waste oil disposal costs, and a credit for coolant use reduction.
Maintenance labor was estimated as four hours per year. Operating labor was estimated
at one hour per shift for all but the smallest unit. The smallest unit required one-half
hour per shift to operate because it was portable and did not require time for coolant
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
collection. Annual costs were calculated as the operating and maintenance costs less the
cost savings from decreased coolant and water use.
The discharge reduction achieved by this module was calculated using the site-specific
PNF for the combined machining coolant wastewater streams. Based on site visit and
vendor information, EPA assumed this technology can achieve an 80% reduction of
coolant discharge. This is achieved by the site treating and reusing 80% of the coolant,
allowing a 20% bleed stream. Therefore, if the site-specific PNF was below 20% of the
median PNF reported in the DCPs, then the technology was assumed to be in place and
the module was not used. For operations for which this module was applied, the
wastewater flow rate was reduced such that the site-specific PNF was equal to 20% of
the median PNF reported in the DCPs.
12.4.5 Centrifugation of Painting Water Curtains
Centrifugation of painting water curtains was applied to all spray painting water curtains.
The capital and annual costs were based on a centrifuge and a holding tank. The
holding tank was sized to hold one-fourth of the site's annual discharge flow. EPA
assumed that this system would operate four times per year.
Direct annual costs included operating and maintenance labor and materials, energy
costs, sludge disposal costs, and a credit for water use reduction. Operating and
maintenance labor varied with the size of unit. Each unit size had an estimated number
of hours per shift as well as an estimated number of hours to empty the sludge basket
during operation.
All water discharged from the Centrifugation system was assumed to be reused in the
spray painting water curtains. Therefore, this module was applied to all sites with spray
painting water curtain discharges, independent of PNF. The Agency assumed that sludge
from the system was contract hauled as a hazardous waste for off-site disposal.
12.4.6 In-Process Ion Exchange
EPA estimated costs for in-process ion exchange of rinse water streams associated with
the following types of electroplating: cadmium, copper, tin, tin/lead, zinc, nickel, and
lead. The technology was based on rinse water leaving the final stage of a
countercurrent cascade rinse, passing through cation and anion ion-exchange columns,
and returning to the first stage of the countercurrent cascade rinse. Based on
information from site visits and literature, EPA assumed that this technology can achieve
a 90% reduction of rinse water discharge from the specific operation for which it is used.
This is achieved by the site recycling 90% of the rinse water, allowing a 10% bleed and
regeneration stream.
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
The ion-exchange columns were designed to be regenerated using centralized (one
system per site) sulfuric acid and sodium hydroxide feed systems. All acid regenerant
streams were sent to electrolytic recovery units for metal reclamation prior to wastewater
discharge. Capital and annual costs for the following equipment were included within
the ion-exchange system:
• Two sets of cation and anion ion-exchange columns (one set to be
regenerated off line while the other set was in use), cation and
anion resin, carbon prefilters, and ancillary equipment;
• An electrolytic recovery unit for acid regenerant;
• An electrolytic recovery tank;
• An ion-exchange effluent pump;
• A centralized sulfuric acid feed system;
• A centralized sodium hydroxide feed system; and
• Two regenerant holding tanks.
For rinse water with countercurrent cascade discharge concentrations of electroplated
metals greater than 200 mg/L, a drag-out recovery tank and electrolytic recovery unit
were designed for installation prior to the countercurrent cascade rinse. The drag-out
recovery tank and electrolytic recovery unit were designed to remove the metal such that
the concentration in the countercurrent cascade rinse was equal to 20 mg/L. One tank
volume of drag-out solution was discharged to the end-of-pipe treatment system per day.
Capital and annual costs for the following additional equipment were included when
drag-out recovery rinsing was included:
• An electrolytic recovery unit for drag-out solution;
• An electrolytic recovery tank;
• A drag-out tank; and
• A drag-out solution transfer pump.
The Agency determined the required column volumes and regeneration frequencies
based on the larger of either the required ionic loading capacities of the columns or the
required column contact times. Electrolytic recovery units were costed based on the
cation concentration in the regenerant or drag-out solutions, as well as target effluent
concentrations. Regenerant addition requirements were based on column resin volumes.
As discussed above, the Agency assumed that ion exchange can achieve a 90% reduction
of rinse water discharge flow. If the site-specific PNF was less than 10% of the median
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
PNF reported in the DCPs for electroplating rinsing, then the technology was assumed to
be in place and the module was not used. For operations for which this module was
applied, the wastewater flow rate was reduced such that the unit operation-specific PNF
was equal to 10% of the median PNF reported in the DCPs. All pollutant
concentrations from the ion-exchange system (except for the metal type reclaimed from
the regenerant solution by electrolytic recovery) were increased accordingly. The
electrolytic recovery units (those used for regenerant solutions) were assumed to treat
only the reclaimed metal. The units were designed to treat to the chemical precipitation
and sedimentation long-term average pollutant concentration discussed in Section 11.0.
After electrolytic recovery, the regenerant solutions were modeled as discharged to the
end-of-pipe treatment system.
Direct annual costs included operating and maintenance labor and materials, energy
costs, raw materials (e.g., sulfuric acid, sodium hydroxide, ion-exchange resins), and
credits for water use reduction and reclaimed metals.
12.4.7 Contract Hauling
The Agency estimated costs for various types of wastes generated on site to be contract
hauled for off-site treatment and disposal. These waste types include:
• Metal-bearing sludge;
• Waste oils;
• Paint sludge;
• Chromium-bearing wastewater;
• Cyanide-bearing wastewater;
• Wastewater containing soil and grease and organic pollutants; and
• Metal-bearing wastewater not included above.
Costs for treatment and disposal of each waste type were estimated in dollars per gallon
of waste. Additional costs were estimated for sites generating annual volumes of waste
less than that of a typical tanker truck hauling capacity (2,200 gallons). The additional
costs represented additional fees charged by the contract hauler for using 55-gallon
drums instead of a tanker truck. The following is a brief summary of how these costs
were applied throughout the design and cost model. Additional details are provided in
the administrative record for this rulemaking.
• EPA assumed a cost of $2.90 per gallon for contract hauling metal-
bearing sludge for landfilling as a hazardous waste. The sludge was
generated by the sludge pressure filtration system, the machining
coolant centrifugation and pasteurization system, and the oil/water
separation system.
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
• EPA assumed a cost of $2.06 per gallon for contract hauling waste
oil for off-site disposal. Waste oil was generated by the machining
coolant centrifugation and pasteurization system, and the oil/water
separation system.
• EPA assumed a cost of $3.72 per gallon for contract hauling paint
sludge for landfilling as a hazardous waste. The sludge was
generated by the painting water curtain centrifugation system.
• EPA assumed a cost of $0.49 per gallon for contract hauling
hexavalent chromium-bearing wastewater for off-site treatment. The
wastewater was contract hauled from sites at which contract hauling
was determined by the cost model to be less expensive than the
chemical reduction of hexavalent chromium system.
• EPA assumed a cost of $0.74 per gallon for contract hauling
cyanide-bearing wastewater for off-site treatment. The wastewater
was contract hauled from sites at which contract hauling was
determined by the cost model to be less expensive than the in-
process ion-exchange system for cyanide-bearing rinse water or the
cyanide destruction system.
• EPA assumed a cost of $1.05 per gallon for contract hauling
wastewater bearing oil and grease or other organic pollutants for
off-site treatment. The wastewater was contract hauled whenever
generated by solvent degreasing operations or from sites at which
contract hauling was determined by the cost model to be less
expensive than the machining coolant centrifugation and
pasteurization system or the oil/water separation system.
• EPA assumed a cost of $0.49 per gallon for contract hauling metal-
bearing wastewater for off-site treatment. The wastewater was
contract hauled from sites at which contract hauling was determined
by the cost model to be less expensive than the in-process or end-of-
pipe ion-exchange systems, the chemical reduction of chelated
metals system, the chemical precipitation and sedimentation system,
and the sludge pressure filtration system.
12.4.8 Oil/Water Separation
EPA estimated costs for batch and continuous systems to separate and remove oil and
grease and organic pollutants prior to chemical precipitation and sedimentation. The
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
Agency assumed that all oil-bearing wastewater streams at each site were commingled
prior to treatment. These wastewater streams are listed below:
• Alkaline treatment and rinse (following an oily waste generating
operation such as machining or heat treatment with oil quench);
• Corrosion preventive coating and rinse;
• Floor cleaning and rinse;
• Grinding and rinse;
• Heat treatment rinse (following oil quench);
• Impact deformation and rinse;
• Machining and rinse;
• Pressure deformation and rinse;
• Testing (dye penetrant) and rinse; and
• Testing (magnetic flux) and rinse.
The technology was based on chemical emulsion breaking followed by oil removal.
Chemical emulsion breaking was either performed using sulfuric acid in a batch system
(for wastewater flow rates less than or equal to 265 gallons per hour), or by using
aluminum sulfate and polymer in a continuous system (for wastewater flow rates greater
than 265 gallons per hour). Oil removal for all batch systems was performed using a belt
skimmer. For continuous systems, oil removal was performed by using either a belt
skimmer (for oil removal rates less than or equal to 50 gallons per hour) or a coalescent
plate separator (for oil removal rates greater than 50 gallons per hour).
Capital and annual costs for the following equipment were included for batch systems:
• Two batch reaction tanks;
• Two motorized reaction tank agitators;
• A reaction tank effluent pump;
• A sulfuric acid feed system;
• Two belt skimmers;
• A waste oil holding tank; and
• A waste oil discharge pump.
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
For continuous chemical emulsion breaking systems, capital and annual costs for the
following equipment were included:
• A flow equalization tank;
• A reaction tank;
• A motorized reaction tank agitator;
• A flow equalization tank effluent pump;
• A reaction tank effluent pump;
• An aluminum sulfate (alum) feed system; and
• A polymer feed system.
For oil removal using a belt skimmer on a continuous system, capital and annual costs
for the following equipment were included:
• A equalization/skimming tank;
• A waste oil holding tank;
• A waste oil tank discharge pump;
• An equalization/skimming tank effluent pump; and
• A belt skimmer.
For oil removal using a coalescent plate separator on a continuous system, capital and
annual costs for the following equipment were included:
• A coalescent plate separator; and
• A coalescent plate separator effluent pump.
Direct annual costs included operating and maintenance labor and materials, energy
costs, raw materials (e.g., sulfuric acid, aluminum sulfate, polymer), and sludge and waste
oil disposal costs. Acid addition requirements for the batch system were based on a
target pH of 2.5. Aluminum sulfate and polymer addition rates for the continuous
system were based on the influent flow rate to the unit. For belt skimmer and
coalescent plate separator (CPS) oil removal systems, the oil removal rate and the oil
removal equipment sizes were based on the oil and grease loading to the system. Waste
oil and CPS sludges were contract hauled for off-site disposal. The effluent from this
system was discharged to the chemical precipitation and sedimentation system. EPA
adjusted effluent flow rates and concentrations from this treatment unit using mass
balances based on the oil removal rate.
12.4.9 Chemical Reduction of Hexavalent Chromium
EPA estimated costs for batch and continuous systems to reduce hexavalent chromium to
trivalent chromium prior to chemical precipitation and sedimentation. The Agency
assumed that all chromium-bearing wastewater streams at each site were commingled
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
prior to treatment and that all chromium in that wastewater was in the hexavalent form.
The chromium-bearing wastewater streams are listed below:
• Acid treatment (with chromic acid) and rinse;
• Anodizing (chromic acid) and rinse;
• Anodizing sealant (with chromium) and rinse;
• Chromate conversion coating and rinse;
• Chemical conversion coating sealant (with chromium) and rinse;
• Electroplating (chromium) and rinse; and
• Wet air pollution control for chromium-bearing operations.
For flow rates less than or equal to 625 gallons per hour, the Agency costed batch
systems based on manual addition of sodium metabisulfite. For flow rates greater than
625 gallons per hour, continuous systems based on sulfonation (i.e., reduction with
gaseous SO2) were costed. Annual costs for the manual addition of sodium metabisulfite
and capital and annual costs for the following equipment were included for batch
systems:
• Two batch reaction tanks;
• Two motorized reaction tank agitators;
• A reaction tank effluent pump; and
• A sulfuric acid feed system.
For continuous systems, capital and annual costs for the following equipment were
included:
• A flow equalization tank;
• A reaction tank;
• A motorized reaction tank agitator;
• A flow equalization tank effluent pump;
• A reaction tank effluent pump;
• A sulfuric acid feed system;
• A continuous sulfur dioxide feed system; and
• A sulfur dioxide supply pump.
Direct annual costs included operating and maintenance labor and materials, energy
costs, and raw materials (e.g., sulfuric acid, sodium metabisulfite, sulfur dioxide).
Sulfuric acid addition requirements were based on a target pH of 2.5, and reduction
reagent addition rates were calculated based on the chromium loading to the system.
The effluent from this system was discharged to the chemical precipitation and
sedimentation system. EPA assumed that all hexavalent chromium was converted to the
trivalent form. EPA also assumed that flow rates and pollutant concentrations (including
total chromium) remained unchanged in this treatment unit.
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
12.4.10 Cyanide Destruction
EPA estimated costs for batch and continuous alkaline chlorination systems to destroy
cyanide prior to chemical precipitation and sedimentation. The Agency assumed that all
cyanide-bearing wastewater streams at each site were commingled prior to treatment.
These wastewater streams are listed below:
• Alkaline treatment (with cyanide) and rinse;
• Electrolytic cleaning (with cyanide) and rinse;
• Electroplating (with cyanide) and rinse;
• Heat treatment quench (cyaniding) and rinse; and
• Wet air pollution control for cyanide-bearing operations.
For flow rates less than or equal to 625 gallons per hour, the Agency costed a batch
system based on manual addition of sodium hypochlorite. For flow rates greater than
625 gallons per hour, systems based on continuous sodium hypochlorite addition were
costed. Capital and annual costs for the following equipment were included for batch
systems:
• Two batch reaction tanks;
• Two motorized reaction tank agitators;
• A reaction tank effluent pump;
• A sodium hydroxide feed system; and
• A sodium hypochlorite feed system.
For continuous systems, capital and annual costs for the following equipment were
included:
• A flow equalization tank;
• A reaction tank;
• A motorized reaction tank agitator;
• A flow equalization tank effluent pump;
• A reaction tank effluent pump;
• A sodium hydroxide feed system; and
• A sodium hypochlorite feed system.
Direct annual costs included operating and maintenance labor and materials, energy
costs, and raw materials (e.g., sodium hydroxide, sodium hypochlorite). Sodium
hydroxide addition requirements were based on a target pH of 11.5, and oxidation
reagent addition rates were calculated based on the cyanide loading to the system.
Cyanide concentrations in the effluent from this treatment unit were assumed to be
equal to the cyanide destruction long-term average concentration (see Section 11.0).
EPA assumed that the flow rate and all other pollutant concentrations remained
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
unchanged in the effluent. The effluent was discharged to the chemical precipitation and
sedimentation system.
12.4.11 Chemical Reduction of Chelated Metals
The Agency estimated costs for preliminary treatment of chelated metals with calcium
hydroxide and sodium borohydride prior to chemical precipitation and sedimentation.
The Agency costed either low-flow batch systems for flow rates less than or equal to
580 gallons per hour or normal batch systems for flow rates greater than 580 gallons per
hour. Annual costs for the manual addition of sodium borohydride and capital and
annual costs for the following equipment were included:
• Two reaction tanks;
• Two motorized reaction tank agitators;
• A calcium hydroxide (lime) feed system (manual feed for low-flow
batch systems); and
• An effluent pump.
Direct annual costs included operating and maintenance labor and materials, energy
costs, and raw materials (e.g., calcium hydroxide, sodium borohydride). The Agency
assumed that all wastewater generated by electroless plating and electroless plating
rinsing operations were commingled and treated by this module. Calcium hydroxide
addition requirements were based on a target pH of 8, and sodium borohydride addition
rates were based on a dosage rate of 2.4 pounds per 1,000 gallons of wastewater. The
effluent from this system was discharged to the chemical precipitation and sedimentation
system. EPA assumed that the flow rate and pollutant concentrations remained
unchanged in the effluent.
12.4.12 Chemical Precipitation and Sedimentation
The Agency estimated costs for low-flow batch, normal batch, and continuous chemical
precipitation and sedimentation systems. All MP&M wastewaters generated on site were
commingled and treated by this technology, including the effluents from the in-process
and end-of-pipe preliminary treatment technologies.
Low-flow batch systems were designed for influent flow rates less than or equal to 580
gallons per hour. Annual costs for the manual addition of calcium hydroxide (lime) and
polymer, and capital and annual costs for the following equipment, were included:
• Two batch reaction tanks;
• Two motorized reaction tank agitators;
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
• A reaction tank effluent pump; and
• A reaction tank sludge pump.
Normal batch systems were designed for influent flow rates greater than 580 and less
than or equal to 2,800 gallons per hour. For these systems, automated feed systems
replace the manual addition of calcium hydroxide and polymer.
Continuous systems were designed for influent flow rates greater than 2,800 gallons per
hour. These systems included capital and annual costs for the following equipment:
• A rapid mix reaction tank with a five minute retention time;
• A motorized rapid mix tank agitator;
• A polymer feed system;
• A calcium hydroxide feed system;
• A clarifier (lamella clarifier for flow rates less than or equal to
18,000 gallons per hour, circular clarifier for flow rates greater than
18,000 gallons per hour);
• A clarifier effluent pump; and
• A clarifier sludge pump.
Calcium hydroxide addition requirements were based on the following: a target pH of 9,
acidity equal to zero, and the stoichiometric quantity required to convert all dissolved
metals to metal hydroxides. Polymer addition requirements were based on a rate of
2 milligrams of polymer for each liter of wastewater treated.
Pollutant concentrations in the effluent from these systems were assumed to be equal to
the chemical precipitation and sedimentation long-term average concentrations (see
Section 11.0). The amount of sludge generated by this system was calculated using site-
specific influent pollutant concentration data for the commingled wastewater. The
sludge was assumed to be 3% solids and was discharged to a sludge thickening tank.
The effluent from this system was either discharged from the site or further treated by
the end-of-pipe ion-exchange system, depending on the technology option. Direct annual
costs included operating and maintenance labor and materials (including the manual
addition of chemicals for low-flow batch systems), energy costs, and raw materials (e.g.,
calcium hydroxide, polymer).
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
12.4.13 Sludge Thickening
The Agency estimated costs for sludge thickening by gravity settling for the sludge
discharged from the chemical precipitation and sedimentation system. The sludge
thickening system increased the solids content of the sludge from 3% to 5% prior to
further dewatering in the sludge pressure filtration system. Capital and annual costs for
the following equipment were included:
• One holding/thickening tank;
• An effluent pump (for the supernatant); and
• A sludge pump.
The sludge from this system was discharged to the sludge pressure filtration system. The
supernatant was discharged to the chemical precipitation and sedimentation system.
Direct annual costs included operating and maintenance labor and materials and energy
costs.
12.4.14 Sludge Pressure Filtration
The Agency estimated costs for a plate-and-frame filter press to increase the solids
content of the sludge from 5% to 35% prior to contract hauling for off-site disposal.
Capital and annual costs for the following equipment were included:
• A plate-and-frame filter press; and
• A sludge pump.
Direct annual costs included operating and maintenance labor and materials, energy
costs, and sludge disposal costs. Costs also account for storage of the sludge prior to
disposal. The filtrate from this system was discharged to the chemical precipitation and
sedimentation system. Maintenance labor is estimated at 2 hours per year. Operating
labor varies from one to three hours per shift depending on the various press capacity
ranges.
12.4.15 End-of-Pipe Ion Exchange
EPA estimated costs for end-of pipe ion exchange for the chemical precipitation and
sedimentation effluent for Option 3 only. This technology was based on a 90% reuse of
the treated effluent with the 10% blowdown discharged from the site. The ion-exchange
columns were regenerated using sulfuric acid and sodium hydroxide feed systems.
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12.0 COSTS OF TECHNOLOGY BASES FOR REGULATIONS
Capital and annual costs for the following equipment were included within the ion-
exchange system:
• Two sets of cation and anion ion-exchange columns (one set to be
regenerated off line while the other set was in use), cation and
anion resin, and ancillary equipment;
• An ion-exchange effluent pump;
• A sulfuric acid feed system;
• A sodium hydroxide feed system; and
• Two fiberglass regenerant holding tanks.
Direct annual costs included operating and maintenance labor and materials, energy
costs, raw materials (e.g., sulfuric acid, sodium hydroxide, ion-exchange resins), contract
hauling costs for regenerant solutions, and credit for water use reduction. The Agency
costed the end-of-pipe ion-exchange columns based on the required column contact
times. Regenerant addition requirements were based on column resin volumes.
Blowdown pollutant concentrations were modeled at the chemical precipitation and
sedimentation long-term average concentrations.
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Table 12-1
MP&M Phase I Capital and Annual Costs
Option
Number
1
2
3
1A
2A
Indirect Dischargers
Total Capital
Investment
(millions of
1989 dollars)
277
433
1,160
434
337
Operating,
Maintenance,
and Monitoring
(millions of 1989
dollars)
267
241
677
236
145
Direct Dischargers
Total Capital
Investment
(millions of 1989
dollars)
45.9
59.0
148
Not applicable
Not applicable
Operating,
Maintenance, and
Monitoring
(millions of 1989
dollars)
14.8
13.1
88.4
Not applicable
Not applicable
Source: MP&M design and cost model.
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Table 12-2
Summary of End-of-Pipe Technologies In Place at MP&M Phase I Sites
Treatment Technology
Oil/water separation
Chemical reduction of hexavalent
chromium
Cyanide destruction
Chemical reduction of chelated
metals
Chemical precipitation and
sedimentation
Sludge thickening
Sludge pressure filtration
Estimated Number
of Sites with
Technology in Place
406
709
351
4
1,650
649
1,290
Estimated Percent
of Sites with
Technology in Place
4
7
3
<1
16
6
12
Source: MP&M Phase I Model Site Profile Database
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Table 12-3
MP&M Phase I Equipment Cost Equations*
Equipment
Agitator
Air-agitation system
Automatic rinse timer
Belt skimmer, batch
Belt skimmer, continuous
Clarifier, circular steel
Clarifier, lamella
Coalescent plate separator
Equation
A
C
A
C
A
C
A
C
A
C
A
C
A
C
A
C
A
C
A
C
A
C
= 210.4 (HP) (f) + 0.05 (C)
= 1.14 * (1585.55 + 125.302 (HP) - 3.27437 (HP)2)
= 210.4 (HP) (f) + 0.05 (C)
= 1.14 * (839.1 + 587.5 (HP))
= 265.96 + 0.54121 (V) - 7.4114 * 10'5(V)2 + 5.2352 * 1Q-9 (V)3
= 1,505.8 + .62931(V) - 1.411 * 10'5 (V)2
= 24
= 409.86
= 2.4 (DPY) + 576 + (4 * (5.5 *1Q-4) (HPD) (DPY))
= 3,863
= 2.4 (DPY) + 576 + (4 * (5.5 *10~4) (HPD) (DPY))
= 4,184
= 2.4 (DPY) + 576 + (0.0175 (HPD) (DPY))
= 3,863
= 2.4 (DPY) + 576 + (0.0175 (HPD) (DPY))
= 4,184
= 1.14 [exp [8.22809 - 0.224781 (In (Y) (0.048)] + 0.0563252 (ln[(Y) (0.048)]2]
= 1.14 [141,197.1 + 72,0979 (4) (0.048) + 0.01065452 [(Y) *0.048]2) + 0.0180092 (ln(F))2]]
= 0.05 (C)
= 6,039.6 + 3.1356 (Y) - 4.659 * 102 (Y)2
= (.01 (C) + 0.038 (GPH))
= 6410.4 + 75.560 (Y) - 3.5688 * 10"2(Y)2
Range of Validity
0.33 < HP < 5
0.25 < HP < 0.33
50 < V < 10,000
NA
OR < 25
25 < OR < 50
OR < 25
25 < OR < 50
300 < Y < 2,800
2 < Y < 300
600 < GPH < 92,000
10 < Y < 700
*A11 costs are calculated in 1989 dollars. Variable definitions are at the end of the table.
-------
MP&M Phase I Equipment Cost Equations'
Equipment
Electrolytic recovery unit
Feed system, aluminum
sulfate (alum)
Feed system, calcium
hydroxide (lime), batch
Feed system, calcium
hydroxide (lime), continuous
Feed system, polymer
Equation
A = [(LBS)(.2)(24)j +[(PT)(AMPS)(.5)(.012)] +[(LBS)(8.95)/10] +[(PT)(ATF)((AMPS/15) + 1)]
C = 7,912
C = 15,824
C = 21,758
C = 29,670
A = 690 (f) (AW)
C = 3,062.8 + 1,394.7 (F) - 45.449 (F)2
A = 6,875.5 + 20.747 (F) + 1.2319 * Hr4(F)2
C = 3.5423 * 104 + 127.17 (F)
A = 1,773.5 + 0.10516 (F) + 3.8552 * 1Q-4(F)2
C = 2.9547 * 10" + 146.24 (F) - 1.2645 * 1Q-2(F)2
A = [57/2,000 * F * HPD * DPY] + [(24 * HPD * DPY)/8 * (0.25 + (0.0025 * F * 8))] + [(24 * DPY)/5]
C = 1,929 + (22.65 * F) - (0.04608 * F2)
A = [57/2,000 * F * HPD * DPY] + [(24 * HPD * DPY)/8 * (0.25 + (0.0025 * F * 8))] + [(24 * DPY)/5]
C = 6,359.7 + (6,573.2 * log(F))
A = f [-17,140 + (22,697 * log (F)) ] + [(57/2,000) * F * HPD * DPY]
C = 19,511 + (F * 698.8)
A = f [-17,140 + (22,697 * log (F)) ] + [(45/2,000) * F * HPD * DPY]
C = 19,511 + (F * 698.8)
A = f [-17,140 + (22,697 * log (F)) ] + [(45/2,000) * F * HPD * DPY]
C = 8.795 * 104 (F * 8.9565)
A = (2.4 * DPY) + 312 + (0.1) (C) + (2.25) (0.989) * F * HPD * DPY
C = 3,668 + (20,666 * F)
Range of Validity
100 < AMPS < 750
100 Amp Cell
250 Amp Cell
500 Amp Cell
750 Amp Cell
0.23 < F < 12.5
Dry
10 < F < 5,000
Dry
5.4 < F < 5,400
Wet
F< 100
100 < F < 5,000
F < 50
50 < F <100
100 < F < 1,000
F<0.5
*A11 costs are calculated in 1989 dollars. Variable definitions are at the end of the table.
-------
Table 12-3 (Continued)
MP&M Phase I Equipment Cost Equations*
Equipment
Feed system, sodium
hydroxide, batch
Feed system, sodium
hydroxide, continuous
Feed system, sodium
hypochlorite
Feed system, sulfur dioxide
(sulfonator)
Feed system, sulfuric acid
Filter press, plate-and-frame
Ion-exchange system
(excluding regeneration feed
systems)
Equation
A = 24 * (16 + 0.5(BPY)) + (0.138)(F)(HPY)
C = 1.14 [exp [7.50026 +0.199364 * In (F) +0.0416602 * (hi (F))2]]
A = (12) (BPY)+ (0.138) (F)(HPY)
C = (1.14) (250)
A = 1.14 [ exp [7.9707 - 4.45846 * 10"3 * In (F) + 0.0225972 * (In (F))2]] (f (6000/8760)) + HPY (F) (1.13)
C = 1.14 [exp [9.63461 +8.36122 * HT3 * ln(F) +0.0241809 * (m(F))2]]
A = 3,192 (f) + (F) (f) (6,480)
C = 652.71 +95.931 (GPH) -0.86955 (GPH)2
A = 1.0865 *104+ 2,779. 1(F)
C = 1.5807 * 10" * 10(1-1133 * 10'(F))
A = [2,724.6 +3.8647 (F) + 1.4692 * 1Q-5(F)2] (f) (6000/8760) +[(6000) (.0442) (F)(f)]
C = 1.14 [exp [8.1441 +0.23345 (In (F)) +0.0180092 (In (F))2]]
A = 48 + 3 (DPY) (HPD)
A = 48 + 6 (DPY) (HPD)
A = 48 + 9 (DPY) (HPD)
C = 4098.5 + 2056.2 (FCV) - 35.576 (FCV)2
A = [(70)(FT3)(24)] + [(134)(FT3)] + [(FT3)(HPD)(DPY)(.047)(1.4)] + [(FT3)(7.23)(.5)(RPY)] + [(FT3)(2,950)(.025)]
C = (2,967)(FT)
A = [(.25)(70)(FT3)(24)] + [(134)(FT3)] +[(3.65)(FT')(HPD)(DPY)(.047)(1.4)] + [(FT3)(7.23)(.5)(RPY)] + [(4)(FT')(2,950)(.025)]
C = (2,373.6)(FT3)
Range of Validity
27 < GPH < 625
1.5 < F < 1,500
27 < GPH
1.5 < F < 1,500
.4 < F < 417
1 < GPH < 42
4.1 < F < 417
0.42 < F < 416.7
0.01 < F < 3,200
1 < FCV < 6
6 < FCV < 15
15 < FCV < 20
1 < FCV < 20
FT3 > 1, manual regeneration
10 > FT3 > 1
FT3 > 1, automatic
regeneration
FT3 > 10
OJ
os
*A11 costs are calculated in 1989 dollars. Variable definitions are at the end of the table.
-------
MP&M Phase I Equipment Cost Equations*
Equipment
Machining coolant
regeneration system
(including holding tanks)
Paint curtain centrifuge
Pump, sludge
Pump, wastewater
Equation
A = [ 32 + (0.5 * SHIFT) * 24] + [0.047 * 18 * 8 * SHIFT]
C = 25,268
A = [(32 + SHIFT) * 24] + [0.047 * 18 * 8 * SHIFT]
C = 67,639
A = [(32 + SHIFT) * 24] + [0.047 * 18 * 8 * SHIFT]
C = 87,738
A = [(32 + SHIFT) * 24] + [0.047 * 18 * 8 * SHIFT]
C = 100,783
A = [(32 + SHIFT) * 24] + [0.047 * 18 * 8 * SHIFT]
C = 117,613
A = [0.25 * (TSS/400,000) * ANNFLOW * 3.78 * 24/3] + [0.047 * 0.4 * 4 * 8 ]
C = 3,995
A = [0.25 * (TSS/400,000) * ANNFLOW * 3.78 * 24/7.6] + [0.047 * 1.5 * 4 * 8 ]
C = 5,950
A = [0.167 * (TSS/400,000) * ANNFLOW * 3.78 * 24/7] + [0.047 * 1.5 * 4 * 8 ]
C = 10,765
A = [l * 4 * 24] + [0.047 * 2.2 * 4 * 8 ]
C = 29,990
A = [l * 4 * 24] + [0.047 * 3.7 * 4 * 8 ]
C = 40,240
A = 1,155.7 + 19.932 (SF) - 7.7145 * 1Q-3(SF)2 + (0.01) (C)
C = 2,582.8 + 23.952 (SF) - 4.2469 * 10"' (SF)2
A = [(1,779.5 + 18.098 (Y)- 2.0632 * 10-' (Y)2)] (f) +0.01(C)
C = 3,196.3 + 3.2367 (Y)+ 4.1585 * 10-"(Y)2
A = [(1779.5 + 18.098 (Y) - 2.0632 * 10'3(Y)2)] (f) + 0.01(C)
C = 602.93+ 44.824 (Y)
Range of Validity
GPM < 1
1 < GPM < 2
2 < GPM < 6
6 < GPM < 10
10 < GPM < 14
GPM < 8
Manual Operation
8 < GPM < 13
Manual Operation
13 < GPM < 16
Semiautomatic
16 < GPM < 26
Automatic
26 < GPM < 53
Automatic
5 < SF < 500
Y > 1,000
27 < Y < 3,500
Y < 1,000
Y<27
*A11 costs are calculated in 1989 dollars. Variable definitions are at the end of the table.
-------
Table 12-3 (Continued)
MP&M Phase I Equipment Cost Equations*
Equipment
Tank, equalization/reaction,
concrete
Tank, equalization/
reaction/rinse, fiberglass
Tank, equalization/reaction,
steel
Tank, holding, concrete
Tank, holding, fiberglass
Equation
A =
C =
A =
C =
A =
C =
A =
C =
A =
C =
A =
C =
A =
C =
A =
C =
A =
C =
A =
C =
0.05 (C)
1.14 [5,800 + 0.8 (V)]
0.05 (C)
1.14 [ exp [4.7308 - 0.0628537
0.05 (C)
1.14 [3100.44 + 1.19041 (V) -
In (V) + 0.0754344 (In (V))2]]
1.7288 * 10-5(V)2]
0.05 (C)
1.14 [692.824 + 6.16706(V)- 3.95367 * 1Q-3(V)2]
0.05 (C)
1.14 [3,128.83 + 2.37281 (V) -
0.05 (C)
1.14 [3100.44 + 1.19041 (V) -
0.05 (C)
1.14 [14,759.8 + 0.0170817(V)
0.02 (C)
1.14 [5,800-1- 0.8 (V)]
0.02 (C)
1.14 [ exp [4.7308 - 0.0628537
0.02 (C)
1.14 [3,100.44 + 1.19041 (V)-
7.10689 * 10-5(V)2]
1.7288 * 10-3(V)2]
-8.44271 * 10-8(V)2]
* ln(V) + 0.0754345 (ln(V))2]]
1.7288 * 10-3(V)2]
Range of Validity
24,000 < V < 500,000
57 < V < 1,000
1,000 < V < 24,000
100 < V < 500
500 < V < 12,000
12,000 < V < 24,000
24,000 < V < 500,000
24,000 < V < 500,000
57 < V < 1,000
1,000 < V < 24,000
N)
OJ
00
*All costs are calculated in 1989 dollars. Variable definitions are at the end of the table.
-------
rnase i equipment L^OSI equations'
Equipment
Tank, holding, steel
Equation
A = 0.02 (C)
C = 1.14(692.824 + 6.16706 (V) - 3.95367 *
A = 0.02 (C)
C = 1.14 [3,128.83 + 2.37281 (V) - 7.10689 *
A = 0.02 (C)
C = 1.14(3,100.44 + 1.19041 (V) - 1.7288 *
A = 0.02 (C)
C = 1.14 [14,759.8 + 0.0170817 (V) - 8.44271
10-' (V)2]
10-5(V)2]
10-5(V)2]
* 10-8(V)2]
Range of Validity
100 < V < 500
500 < V < 12,000
12,000 < V < 25,000
25,000 < V < 500,000
Source: MP&M design and cost model.
Variable Definitions:
A =
£3 ANNFLOW
J£ ATF
AMPS
AW
BPY
C
DPY
F
f
FT3
FCV
G
GPH
GPM
HP
Direct annual costs (1989 dollars per year)
Annual flow through equipment (gallons per year)
Anode type factor (ATF = 0.708 for all metal types except
Pb, Sn, and Pb-Sn. ATF = 0.035 for Pb, Sn, and Pb-Sn)
Cell amperage (amps)
Weight of aluminum (pounds)
Number of batches per year
Direct capital equipment costs (1989 dollars)
Days of operation per year
Chemical feed rate (pounds per hour)
Fraction of time equipment is in operation
Resin volume required (cubic feet)
Filter cake volume (cubic feet)
Sludge disposal rate (gallons per hour)
Wastewater flow rate (gallons per hour)
Wastewater flow rate (gallons per minute)
Power requirement (horsepower)
LBS = Pounds of metal reclaimed per year (Ibs per yr)
PT = Plate-out time (hours)
HPD = Equipment operational hours per day
HPY = Plant operating hours (hours per year)
LC = Lime cost ($ per Ib, March 1982)
NA = Not applicable
NB = Number of batches per day
OR = Oil removal rate (gallons per hour)
RPY = Regenerations per year
S = Clarifier surface area (square feet)
SA = Filter surface area (square feet)
SF = Sludge flow (gallons per minute)
SHIFT = Number of shifts operated per year
TSS = Concentration of total suspended solids (mg per L)
V = Tank volume (gallons)
W = Weight of chemical (pounds)
Y = Wastewater flow rate (gallons per minute)
*A11 costs are calculated in 1989 dollars. Variable definitions are at the end of the table.
-------
Table 12-4
Components of Total Capital Investment
Number
1
2
3
4
5
6
7
Item
Equipment capital costs including
required accessories, installation, delivery,
electrical and instrumentation, yard
piping, enclosure, pumping, and retrofit
allowance
Engineering/ administrative and legal
Secondary containment/land costs
Total plant cost
Contingency
Contractor's fee
Total capital investment
Cost
Direct capital cost
10% of item 1
10% of item 1
Sum of items 1 through 3
15% of 4
10% of item 4
Sum of items 4 through 6
Source: MP&M design and cost model.
12-40
-------
In-Plant <
End-of-Pipe
OPTION 3
OPTION 2
OPTION 1
In-Process
Flow
Reduction &
Pollution
Prevention
End-of-Pipe
Treatment
Advanced
End-of-Pipe
Treatment
In-Plant
End-of-Pipe
Flow reduction for rinses:
Flow restrictors
Conductivity sensors
Timed rinsing
Counter current cascade rinsing
Flow reduction for other operations:
Manual control of discharge
Maintenance of bath chemistry
Centrifugation and pasteurization of machining coolant
Centrifugation of painting water curtains
Ion exchange of certain electroplating rinse waters
Electrolytic metal recovery for drag-out recovery
rinsing and ion-exchange regenerant solutions
Oil/water separation
Chemical reduction of hexavalent chromium
Cyanide destruction
Chemical reduction of chelated metals
Contract hauling of solvent degreasing wastewaters
Chemical precipitation and sedimentation
Sludge thickening
Sludge pressure filtration
Advanced End-of-Pipe Treatment:
Ion Exchange
Reverse Osmosis
Major reuse of process wastewater
Additional options considered for indirect dischargers:
1A Option 1 for sites with discharge rates below one-millon gallons per year. Option 2 for the remaining sites.
2A Exempt sites with discharge rates below one-million gallons per year, Option 2 for the remaining sites.
Figure 12-1. Relationship Among Options
RPP051.pm5
010601.pmM
-------
XlndividualN
( process wastewater)
no
streams S
Is the
PNF greater
than 10 times the
edian PNF
Is this
wastewater stream
applicable for flow
reduction for
rinses?
Is the PNF
greater than the
median PNF?
Does the
site discharge
paint curtains or
machining
coolant
Is the PNF
greater than the
median PNF?
Countercurrent
Centrifugation
and pasteurization
of machining
coolants
Centrifugation
s this an
no / electroplating
rinsewater applicable
to ion
xchange
water curtains
ischargeto^\
end-ofpipe ) I toPOTWor J
nt systenj/ N^surface waterX
Is the
PNF greater
than 0.1 times
the median
NF?
ion exchange
treatment system
Figure 12-2. Logic Used to Apply In-process Technologies and Practices
12-42
-------
'astewater
streams from
individual processes
or in-process
controls
the
wastewater
contain chromium,
cyanide,
chelated metal,
oil, or
vent
Combine
chromium-
bearing
wastewater
Combine
cyanide-
bearing
wastewater
Chemical
reduction of
hexavalent
chromium
Combine
chelated
metal-bearing
wastewater
Cyanide
destruction
Chemical
reduction
of chelated
metals
Combine
oil-bearing
wastewater
Combine
solvent-bearing
wastewater
Oil/water
separation
Contract haul for
off-site
treatment
and disposal
Combine
all
wastewater
streams
Contract haul
for off-site
disposal
Chemical
precipitation
and
sedimentation
Wastewater
Discharge to
surface water or>
POTW (Options
' 0.1A.2A.21 '
End-of-pipe
ion exchange
(Option 3)
Return 90% of
treated water to
unit operations
for reuse
Discharge to
surface water
or POTW
Figure 12-3. Logic Used to Apply End-of-pipe Technologies and Practices
12-43
-------
-------
13.0 POLLUTANT LOADING AND REDUCTION ESTIMATES
13.0 POLLUTANT LOADING AND REDUCTION ESTIMATES
This section describes EPA's estimation of industry pollutant loadings and pollutant
reductions for each of the Metal Products and Machinery (MP&M) technology options
described in Section 10.0. The Agency estimated pollutant loadings and reductions from
MP&M sites to evaluate loadings to surface waters and publicly-owned treatment works
(POTWs) and to assess the cost-effectiveness of each MP&M technology option in
reducing these loadings. The results from each of these assessments are presented in
separate EPA documents entitled MP&M Phase I Regulatory Impact Analysis and
MP&M Phase I Economic Impact Analysis. Pollutant loadings for MP&M direct and
indirect dischargers are presented in Tables 13-1 and 13-2, respectively. Pollutant
reductions for MP&M direct and indirect dischargers are presented in Tables 13-3 and
13-4, respectively.
Pollutant loadings and pollutant reductions were estimated using the following steps:
1. Field sampling data were analyzed to determine production-
normalized pollutant loadings (PNPLs) from sampled operation and
metal type combinations.
2. Data were modelled to estimate PNPLs for cases in which particular
unit operation and metal type combinations were not sampled but
the unit operation performed on a different metal type(s) was
sampled.
3. Data were transferred from unit operations with similar wastewater
characteristics to estimate PNPLs for unit operations that were not
sampled.
4. PNPLs were used in the model site development effort (see
Section 12.1) to estimate the concentration of each pollutant of
concern in each model site wastewater stream.
5. The model site database was used to calculate industry
raw wastewater pollutant loadings from the MP&M
Phase I Category.
6. The MP&M Design and Cost Model (see Section 12.2.3) was used
to estimate pollutant loadings at baseline and post compliance for
each of the MP&M technology options.
7. Pollutant reductions for each technology option were calculated
from the Design and Cost Model output by subtracting the baseline
loadings from each post-compliance loading.
13-1
-------
13.0 POLLUTANT LOADING AND REDUCTION ESTIMATES
Figure 13-1 summarizes these steps used to estimate MP&M Phase I pollutant loadings
and reductions for each technology option. Section 13.1 describes the data sources and
major assumptions used for calculating the PNPLs. Section 13.2 describes the calculation
of PNPLs for each unit operation and metal type combination, including cases for which
data modelling and data transfers were performed. Section 13.3 presents the results of
the raw, baseline, and post-compliance pollutant loading and reduction calculations.
To estimate pollutant loadings, the Agency calculated production-normalized pollutant
loadings (PNPLs) for each unit operation and metal type combination based on data
collected during the field sampling program and responses to the MP&M data collection
portfolios (DCPs). The PNPLs represent the mass of pollutants generated per unit of
production (e.g., mg/ft2 or mg/lb removed). The units of production used to normalize
the pollutant loadings for each unit operation are presented in Section 5.0, Table 5-4.
The Agency used production to normalize pollutant loadings to account for the varying
amounts of production through unit operations at MP&M sites. As discussed below, the
amount of pollutants generated from MP&M unit operations is dependent on the
amount of production through an operation. For example, if one operation at an
MP&M site has twice as much production as a corresponding operation at another site,
the first operation is expected to discharge approximately twice the mass of pollutants as
the second operation. By normalizing the discharge of pollutants to production, EPA
was able to account for the varying levels of production at MP&M sites.
EPA used a production-based approach to estimate pollutant loadings for each unit
operation and metal type combination because pollutant loadings depend primarily on
the amount of production through an operation rather than the amount of water used to
perform the operation. The sources of pollutants generated while performing MP&M
unit operations are the parts processed in the operation, contaminants present on the
parts (e.g., oil and grease), and process baths (including materials applied to the parts).
Because discharges of pollutants from these sources are directly related to production,
the amount of pollution generated by a unit operation is primarily dependent on
production and relatively independent of the amount of water used to carry the
pollutant. While adding excess process water will reduce the concentrations of pollutants
in the discharged stream, the total mass of pollutants discharged will remain constant
with constant production. It should be noted that while water use reduction will not
reduce the total mass of pollutants discharged from an operation, additional pollution
prevention benefits are inherently associated with reduced water use. These benefits
include reductions in wastewater treatment chemical usage and sludge generation, and
reduced wastewater treatment system capacity requirements.
The Agency developed separate PNPLs for each unit operation and metal type
combination identified by DCP respondents to account for variation in pollutant loadings
across the variety of unit operations performed and metal types processed at MP&M
sites (e.g., EPA expects electroplating operations to have different PNPLs than painting
13-2
-------
13.0 POLLUTANT LOADING AND REDUCTION ESTIMATES
operations, and grinding of zinc parts to have different PNPLs than grinding of iron
parts).
13.1 Data Sources
The Agency used data from the following sources to estimate pollutant loadings for each
unit operation:
• Analytical data collected during sampling at Phase I MP&M sites;
• Analytical data collected during sampling at Phase II MP&M sites;
and
• Analytical data from previously promulgated metals regulations
(non-MP&M sites).
When flow and production data associated with analytical data for a sampled unit
operation were not available, the Agency used the median production-normalized flow
(PNF, in gallons per unit of production) for the unit operation based on data provided in
the DCPs. Table 5-4 lists the production normalizing parameters and median
production-normalized flows for each unit operation. Data from MP&M sampling
episodes are contained in Sampling Episode Reports (SERs) for each sampled site; these
reports, as well as data from MP&M DCPs and previous metals regulations used in this
assessment, are included in the administrative record for this rulemaking.
13.1.1 Data Hierarchy
To characterize MP&M unit operations, EPA used the data sources listed above based
on the following hierarchy.
1. Analytical data from Phase I MP&M sites were used where
available.
2. If analytical data were not available from Phase I MP&M sites,
analytical data collected at Phase II MP&M sites and non-MP&M
sites were used for each unit operation for which these data were
available. The Agency used Phase II or non-MP&M data for unit
operation and metal type combinations which were common to
Phase I, Phase II, and non-MP&M sites. Because both Phase II and
non-MP&M data were considered equally representative of MP&M
Phase I unit operations, these data were given equal weight when
used.
13-3
-------
13.0 POLLUTANT LOADING AND REDUCTION ESTIMATES
13.1.2 Use of Data for Nondetected Pollutants
In developing PNPLs, the Agency assumed that all nondetected pollutants of concern
were present at the detection limit (Section 8.0 includes a discussion of pollutants of
concern). The Agency made this assumption based on process considerations and on
analytical data available from the MP&M sampling program. Each pollutant of concern
was expected to be present in MP&M wastewater because each pollutant of concern was
generated by MP&M processes and was detected at least three times during the MP&M
sampling program. As discussed below, EPA made exceptions to this methodology for
cyanide and organic pollutants.
The source of cyanide in cyanide-bearing unit operations is soluble cyanide salts added
to the process bath rather than the raw material processed. Based on process
considerations (e.g., the use of cyanide salts to control electroplating rates for the unit
operation), MP&M sampling data, and available technical literature, the Agency
developed a list of unit operations expected to contain cyanide. These unit operations
are alkaline cyanide treatment, electrolytic cyanide cleaning, cyanide electroplating,
cyaniding heat treating (quench), air pollution control for these operations, and
associated rinses. For pollutant loadings and reduction estimates, the Agency considered
these to be the only MP&M unit operation expected to contain cyanide; therefore, for
unit operations not expected to contain cyanide, nondetects for cyanide were assumed to
be zero.
The sources of organic pollutants in MP&M unit operations are organic additives added
to process solutions, organic materials present on the parts, or external contamination by
organic pollutants (e.g., oil or grease). The Agency identified the following as operations
expected to generate organic pollutants: alkaline treatment, adhesive bonding, assembly,
barrel finishing, chemical machining, corrosion preventive coating, floor cleaning,
grinding, heat treating, impact deformation, machining, painting, polishing, pressure
deformation, solvent degreasing rinsing, metallic coating stripping, organic coating
stripping, dye penetrant testing, hydraulic testing, associated rinses, and non-associated
rinsing (see Section 5.0, unit operation number 36 for a description of these rinses). The
Agency identified unit operations expected to generate organic pollutant-bearing
wastewaters based on the following criteria: (1) based on process considerations, organic
pollutants were expected to be present in wastewater from these operations, (2) organic
pollutants were detected for these operations during MP&M sampling efforts, or
(3) organic pollutants were reported in the DCPs as known or believed to be present in
wastewater from these operations. For these operations, nondetected organic pollutants
were assumed to be present at the detection limit. For unit operations not expected to
contain organic pollutants, nondetects for these pollutants were assumed to be zero.
13.2 Calculation of Unit Operation Production-Normalized Pollutant Loadings
The Agency calculated PNPLs for each MP&M unit operation and metal type
combination using the data sources identified in Section 13.1. For most unit operations,
13-4
-------
13.0 POLLUTANT LOADING AND REDUCTION ESTIMATES
the metal type was defined as the base metal on which the unit operation was
performed. For the following unit operations, the Agency used process considerations
and available analytical data to determine that the pollutant loadings depend primarily
on the metal applied rather than the base metal: electroplating, electroless plating,
mechanical plating, and metal spraying. For painting, floor cleaning, and wet air
pollution control, the Agency believes that the PNPLs do not vary by base metal type;
therefore, PNPLs for these unit operations were not calculated separately for each base
metal type processed.
The Agency calculated PNPLs for each unit operation and metal type combination using
the following three steps.
1. Unit operation PNPLs were calculated for each metal type for which
analytical data were available from the data sources described in
Section 13.1.
2. Unit operation PNPLs were modelled for each metal type for which
analytical data were not available from the data sources described in
Section 13.1. Data modelling was based on data available for the
unit operation performed on other metal types.
3. Unit operation PNPLs were transferred to unit operations for which
data were not available for any metal type from the data sources
described in Section 13.1. Data were transferred from unit
operations that were expected to have similar wastewater
characteristics based on process considerations.
Sections 13.2.1 through 13.2.3 describes these steps. Documentation for these
calculations is contained in the administrative record for this rulemaking.
13.2.1 Production-Normalized Pollutant Loadings for Each Unit Operation and
Metal Type Combination With Available Data
The Agency calculated PNPLs for each unit operation and metal type combination for
which analytical data were available by multiplying the pollutant concentrations (mg/L)
by the production-normalized flow (L/unit of production) associated with the sample.
As mentioned above, the Agency used the median production-normalized flow from DCP
data when the associated production-normalized flow for a sample was not available.
As described in Section 4.0, for flowing wastewater streams, the Agency collected
multiple samples over several days at a single sampling point (i.e., unit operation) to
account for the potential variability of wastewater characteristics over time. EPA
calculated PNPLs for these sampling points by averaging PNPLs for the samples
collected on multiple days at the same sampling point. For example, if three one-day
composite samples for acid treatment rinsing of steel parts were collected to characterize
13-5
-------
13.0 POLLUTANT LOADING AND REDUCTION ESTIMATES
acid treatment rinsing, the PNPLs for each pollutant on each of the three days were
averaged to calculate the PNPLs for the sampling point.
The Agency averaged PNPLs for samples collected at the same site for the same unit
operation and metal type combination. For example, if samples for acid treatment
rinsing of steel parts were collected at two different sampling points at the same site,
PNPLs for these two sampling points were averaged to calculate the PNPL for this unit
operation and metal type combination at this site. Because the Agency believes that the
PNPL variability is greater between sites than between unit operations within a site,
equal weight was given to data from each site when calculating PNPLs. EPA then
calculated PNPLs for each unit operation and metal type combination by averaging
PNPLs for samples collected at different sites for the same unit operation and metal
type.
13.2.2 Production-Normalized Pollutant Loadings Modelling Within Unit
Operations
The Agency developed a computer algorithm to model PNPLs for unit operations for
which analytical data were available for some but not all metal types. This algorithm
modelled PNPLs based on the average PNPLs for the same unit operation when
performed on other metal types. The algorithm was applicable only when data were
available for the unit operation performed on another metal type. In cases where
analytical data were not available for a unit operation, PNPLs were transferred from
another MP&M unit operation (see Section 13.2.3). Supporting documentation for
modelling of PNPLs is contained in the administrative record for this rulemaking.
13.2.3 Production-Normalized Pollutant Loadings Data Transfer Across Unit
Operations
The Agency transferred PNPLs to unit operations for which analytical data were not
available from Phase I or Phase II MP&M sites or from non-MP&M sites. EPA
transferred PNPLs from unit operations expected to have similar wastewater
characteristics based on process considerations. Process considerations included the
purpose of the unit operation (e.g., metal removal, contaminant removal), the purpose of
the process water use (e.g., contact cooling water, cleaning solution), and the wastewater
flow per unit of production (i.e., production-normalized flow) as reported by MP&M
DCP respondents. Supporting documentation for all data transfers of unit operation
PNPLs is contained in the administrative record for this rulemaking.
13.3 Pollutant Loadings and Reductions
The Agency calculated PNPLs for each pollutant of concern (see Section 8.0) for each
unit operation and metal type combination contained in the model site profile database
(see Section 12.2). The concentration of each pollutant in each model site wastewater
13-6
-------
13.0 POLLUTANT LOADING AND REDUCTION ESTIMATES
stream was calculated using the following equation (for this example, surface area is used
as the production-normalized parameter):
CONC /L = [pNPL(mg pollutant/sq ft processed)] x [PROD(sq ft/hr)]
" [FLOW (gal/hr)] x [3.78 L/gal]
After pollutant concentrations were added to the model site profile database, industry
pollutant loadings for raw wastewater, baseline, and post-compliance at each option were
calculated. Industry baseline pollutant loadings were subtracted from the industry post-
compliance pollutant loadings to determine pollutant reductions for each option. The
results of the pollutant loadings and reductions calculations are presented in the
following sections. All pollutant loadings and reductions are presented using 1989 as the
basis year.
13.3.1 Calculation of Industry Raw Wastewater Pollutant Loadings
Industry raw wastewater pollutant loadings represent the industry pollutant loadings
before accounting for pollutant removal by treatment technologies in place at MP&M
sites. EPA estimated site-specific raw wastewater pollutant loadings by summing the
pollutant loadings for each wastewater stream at each model site.
The site-specific raw wastewater pollutant loadings were then scaled up to the industry
using weighting factors derived statistically for each model site, as discussed in
Section 4.0. The scaled-up site-specific pollutant loadings were summed to calculate the
industry raw wastewater pollutant loadings. The results of the statistical scale-up for
industry raw wastewater annual pollutant loadings for direct and indirect dischargers are
presented in Tables 13-1 and 13-2, respectively. Table 13-1 indicates that the industry
raw wastewater annual pollutant loadings for MP&M Phase I direct dischargers include
approximately 5,460,000 Ib/yr of priority metals, 691,000 Ib/yr of cyanide,
107,000,000 Ib/yr of oil and grease, and 9,220,000 Ib/yr of total suspended solids.
Table 13-2 indicates that the industry raw wastewater annual pollutant loadings for
MP&M Phase I indirect dischargers includes approximately 26,900,000 of priority metals,
9,110,000 Ib/yr of cyanide, 691,000,000 Ib/yr of oil and grease, and 42,000,000 Ib/yr of
total suspended solids.
13.2.2 Calculation of Industry Baseline Pollutant Loadings
Industry baseline pollutant loadings represent the industry pollutant loadings after
accounting for removal of pollutants by treatment technologies in place at MP&M sites.
Section 12.0 describes the assessment of technology in place for each model site. As
described above, site-specific raw wastewater pollutant loadings were developed for each
model site. A baseline run of the cost model was performed to calculate site-specific
13-7
-------
13.0 POLLUTANT LOADING AND REDUCTION ESTIMATES
baseline pollutant loadings for each model site. This baseline run used the technologies
in place at each site rather than the MP&M technology options. Site-specific baseline
pollutant loadings were then calculated as the difference between site-specific raw
wastewater pollutant loadings and pollutant removals by technologies in place at each
MP&M model site.
Site-specific baseline pollutant loadings were scaled up to industry using weighting
factors derived statistically for each model site. The scaled-up site-specific baseline
loadings were summed to calculate industry baseline pollutant loadings. The results of
the statistical scale-up for industry baseline pollutant loadings are presented in
Tables 13-1 and 13-2. Table 13-1 indicates that the industry baseline annual pollutant
loadings for MP&M Phase I direct dischargers include approximately 557,000 Ib/yr of
priority metals, 3,840 Ib/yr of cyanide, 18,200,000 Ib/yr of oil and grease, and
2,590,000 Ib/yr of total suspended solids. Table 13-2 indicates that the industry baseline
annual pollutant loadings for MP&M Phase I indirect dischargers includes approximately
6,100,000 Ib/yr of priority metals, 170,000 Ib/yr of cyanide, 170,000,000 Ib/yr of oil and
grease, and 17,700,000 Ib/yr of total suspended solids.
13.3.3 Calculation of Option-Specific Industry Pollutant Loadings and Pollutant
Reductions
Option-specific pollutant loadings (i.e., post-compliance pollutant loadings for each
option) represent the total industry pollutant loadings after the application of each
MP&M technology option. Option-specific pollutant reductions represent total industry
pollutant removal for each technology option. The Agency calculated site-specific raw
wastewater pollutant loadings and baseline pollutant loadings as described above.
Option-specific pollutant reductions for each model site were calculated as the difference
between site-specific baseline pollutant loadings and option-specific pollutant loadings.
These calculations were performed using the MP&M Phase I Design and Cost Model
(see Section 12.0).
Option-specific pollutant loadings and pollutant reductions were scaled up to industry
using weighting factors derived statistically for each model site. The scaled-up site-
specific loadings and reductions for each option were summed to calculate the option-
specific industry pollutant loadings and reductions. The results of the statistical scale-up
for option-specific pollutant loadings are presented in Tables 13-1 (for direct dischargers)
and 13-2 (for indirect dischargers). The results of the statistical scale-up for option-
specific pollutant reductions are presented in Tables 13-3 (for direct dischargers) and
13-4 (for indirect dischargers). These results were used to select the technology basis for
effluent limitations guidelines and standards, as discussed in Section 15.0.
13-8
-------
Table 13-1
Summary of Pollutant Loadings by Option for MP&M Phase I Direct Dischargers1
Pollutant
ANTIMONY
ARSENIC
CADMIUM
CHROMIUM
COPPER
LEAD
NICKEL
SELENIUM
SILVER
THALLIUM
ZINC
TOTAL PRIORITY METALS
CYANIDE
TOTAL CYANIDE
OIL AND GREASE
TOTAL OIL AND GREASE
TOTAL SUSPENDED SOLIDS (TSS)
TOTAL TSS
ALUMINUM
BARIUM
Industry Raw Wastewater
Pollutant Loading
(Ibs/yr)
4,220
1,690
20,600
3,060,000
222,000
18,200
1,650,000
1,250
11,100
1,240
467,000
5,460,000
691,000
691,000
107,000,000
107,000,000
9,220,000
9,220,000
431,000
56,300
Industry Baseline
Pollutant Loading
(Ibs/yr)
4,160
1,660
2,860
357,000
17,900
16,100
63,400
1,230
386
1,220
91,000
557,000
3,840
3,840
18,200,000
18,200,000
2,590,000
2,590,000
63,100
7,610
Option 1
Pollutant Loading
Obs/yr)
3,630
1,600
2,560
2,860
9,860
16,200
8,740
1,030
259
1,170
6,750
54,700
0.930
0.926
249,000
249,000
671,000
671,000
16,900
7,720
Option 2, 1 A. and 2 A
Pollutant Loading
(Ibs/yr)
3,320
1,580
2,060
1,550
5,590
15,400
5,070
904
168
1,150
3,700
40,500
0.0500
0.0496
153,000
153,000
364,000
364,000
11,400
5,430
Option 3 Pollutant
Loading
(Ibs/yr)
330
156
205
154
557
1,530
505
89.6
16.7
113
368
4,020
0.00
0.00496
15,200
15,200
36,300
36,300
1,140
540
'Pollutant loadings for calcium, magnesium, and sodium are not presented in this table because these are typical wastewater treatment chemicals at MP&M sites. Pollutant loadings for acidity,
pH, and total alkalinity are not presented because they are used as performance parameters for chemical precipitation and settling systems.
-------
Table 13-1 (Continued)
Summary of Pollutant Loadings by Option for MP&M Phase I Direct Dischargers1
Pollutant
BORON
COBALT
IRON
MANGANESE
MOLYDBENUM
TIN
TITANIUM
VANADIUM
TOTAL NONCONVENTIONAL METALS
AMMONIA AS N
CHEMICAL OXYGEN DEMAND (COD)
CHLORIDE
FLUORIDE
SULFATE
TOTAL DISSOLVED SOLIDS
TOTAL KJELDAHL NITROGEN
TOTAL RECOVERABLE PHENOLICS
TOTAL PHOSPHORUS
TOTAL OTHER NONCONVENTIONALS
1,1,1-TRICHLOROETHANE
1 , 1-DICHLOROETHANE
Industry Raw Wastewater
Pollutant Loading
(Ibs/yr)
85,200
34,200
13,900,000
206,000
289,000
46,400
22,500
2,700
15,000,000
131,000
131,000,000
80,000,000
666,000
19,500,000
383,000,000
247,000
11,100
1,850,000
615,000,000
431
189
Industry Baseline
Pollutant Loading
(Ibs/yr)
84,500
3,840
398,000
50,500
16,800
3,630
4,290
1,560
634,000
92,600
6,500,000
14,600,000
89,200
6,580,000
67,900,000
155,000
10,100
471,000
96,400,000
322
187
Option 1
Pollutant Loading
(Ibs/yr)
81,500
879
26,300
3,230
14,500
2,800
4,620
1,450
160,000
53,400
1,430,000
5,130,000
39,300
6,470,000
36,800,000
110,000
4,550
53,400
50,100,000
217
143
Option 2, 1A, and 2A
Pollutant Loading
(Ibs/yr)
79,000
553
14,200
1,940
14,100
2,200
3,100
1,120
133,000
39,600
761,000
4,040,000
24,200
5,290,000
21,300,000
80,000
3,550
29,200
31,600,000
161
81.0
Option 3 Pollutant
Loading
(Ibs/yr)
7,710
55.0
1,420
193
1,400
219
308
111
13,100
3,960
76,000
402,000
2,410
526,000
2,120,000
7,990
354
2,910
3,140,000
16.1
8.06
-------
Table 13-1 (Continued)
Summary of Pollutant Loadings by Option for MP&M Phase I Direct Dischargers1
Pollutant
4-CHLORO-3-METHYLPHENOL
ETHYLBENZENE
METHYLENE CHLORIDE
NAPHTHALENE
2-NITROPHENOL
PHENOL
BIS(2-ETHYLHEXYL)PHTHALATE
DI-N-BUTYL PHTHALATE
PHENANTHRENE
TETRACHLOROETHENE
TOLUENE
TOTAL PRIORITY ORGANICS
2-BUTANONE
2-METHYLNAPHTHALENE
2-PROPANONE
ALPHA-TERPINEOL
BENZOIC ACID
BENZYL ALCOHOL
HEXANOIC ACID
N-DECANE
N-DOCOSANE
Industry Raw Wastewater
Pollutant Loading
(Ibs/yr)
2,390
329
1.120
2,030
2,840
2,890
2,680
2,680
1,980
372
209
20,200
38,300
1,990
3,750
10,300
7,920
5,050
1,710
1,990
11,900
Industry Baseline
Pollutant Loading
(Ibs/yr)
1,330
294
365
470
483
1,730
1,700
1,040
465
350
204
8,940
8,650
635
1,850
8,910
954
3,870
633
492
1,360
Option 1
Pollutant Loading
dbs/yr)
781
148
337
288
471
873
1.410
534
289
327
134
5,950
908
517
1,120
550
776
916
484
302
295
Option 2, 1A, and 2A
Pollutant Loading
(Ibs/yr)
512
96.4
215
154
288
589
978
287
158
259
83.8
3,860
443
334
530
348
413
548
332
167
153
Option 3 Pollutant
Loading
(Ibs/yr)
51.1
9.62
21.4
15.3
28.7
58.7
97.5
28.7
15.8
25.8
8.34
385
44.2
33.4
52.8
34.7
41.3
54.7
33.1
16.6
15.2
'Pollutant loadings for calcium, magnesium, and sodium are not presented in this table because these are typical wastewater treatment chemicals at MP&M sites. Pollutant loadings for acidity,
pH, and total alkalinity are not presented because they are used as performance parameters for chemical precipitation and settling systems.
-------
Table 13-1 (Continued)
Summary of Pollutant Loadings by Option for MP&M Phase I Direct Dischargers1
Pollutant
N-DODECANE
N-EICOSANE
N-HEXACOSANE
N-HEXADECANE
N-OCTACOSANE
N-OCTADECANE
N-TETRACOSANE
N-TETRADECANE
N-TRIACONTANE
TOTAL NONCONVENTIONAL ORGANICS
Industry Raw Wastewater
Pollutant Loading
(Ibs/yr)
15,600
4,820
9,100
9,490
7,580
4,070
12,000
22,700
3,600
172,000
Industry Baseline
Pollutant Loading
(Ibs/yr)
4,490
718
1,290
7,890
1,180
1,950
1,560
21,300
869
68,600
Option 1
Pollutant Loading
(Ibs/yr)
1,800
470
495
693
672
571
672
672
611
12,500
Option 2, 1A, and 2 A
Pollutant Loading
(Ibs/yr)
1,000
243
256
427
348
362
348
417
347
7,020
Option 3 Pollutant
Loading
(Ibs/yr)
99.9
24.2
25.6
42.7
34.8
36.2
34.8
41.6
34.6
700
Source: MP&M Phase I Pollutant Loadings.
-------
Table 13-2
Summary of Pollutant Loadings by Option for MP&M Phase I Indirect Dischargers1
Pollutant
ANTIMONY
ARSENIC
CADMIUM
CHROMIUM
COPPER
LEAD
NICKEL
SELENIUM
SILVER
THALLIUM
ZINC
TOTAL PRIORITY METALS
CYANIDE
TOTAL CYANIDE
OIL AND GREASE
TOTAL OIL AND GREASE
TOTAL SUSPENDED SOLIDS (TSS)
TOTAL TSS
ALUMINUM
Industry Raw
Wastewater
Pollutant
Loading
(Ibs/yr)
13,400
5,450
48,100
15,500,000
3,510,000
127,000
2,100,000
4,010
748,000
5,090
4,880,000
26,900,000
9,110,000
9,110,000
691,000,000
691,000,000
42,000,000
42,000,000
3,570,000
Industry
Baseline
Pollutant
Loading
(Ibs/yr)
12,300
5,300
28,100
2,280,000
1,100,000
119,000
958,000
3,910
37,900
4,970
1,560,000
6,100,000
170,000
170,000
170,000,000
170,000,000
17,700,000
17,700,000
577,000
Option 1
Pollutant
Loading
(Ibs/yr)
11,200
4,900
16,700
14,400
47,300
81,200
35,600
3,490
1,430
4,550
33,500
254,000
37.9
37.9
1,130,000
1,130,000
3,240,000
3,240,000
100,000
Option 2
Pollutant
Loading
(Ibs/yr)
9,670
4,480
11,700
8,900
31,200
61,800
23,800
3,280
979
3,760
21,200
181,000
6.01
6.01
793,000
793,000
2,130,000
2,130,000
65,500
Option 3
Pollutant
Loading
(Ibs/yr)
966
448
1,170
888
3,110
6,170
2,380
328
97.9
376
2,120
18,100
0.600
0.601
79,200
79,200
213,000
213,000
6,540
Option 1A
Pollutant
Loading
(Ibs/yr)
9,670
4,490
11,800
9,010
31,500
62,100
24,100
3,290
988
3,760
21,500
182,000
6.27
6.27
801,000
801,000
2,150,000
2,150,000
66,200
Option 2A
Pollutant
Loading
(Ibs/yr)
10,100
4,610
15,800
89,100
59,100
76,200
82,800
3,330
4,590
3,810
147,000
497,000
1,310
1,310
22,900,000
22,900,000
5,740,000
5,740,000
255,000
OJ
I
h-*
U)
'Pollutant loadings for calcium, magnesium, and sodium are not presented in this table because these are typical wastewater treatment chemicals at MP&M sites. Pollutant loadings for acidity,
pH. and total alkalinity are not presented because they are used as performance parameters for chemical precipitation and settling systems.
-------
Table 13-2 (Continued)
Summary of Pollutant Loadings by Option for MP&M Phase I Indirect Dischargers1
Pollutant
BARIUM
BORON
COBALT
IRON
MANGANESE
MOLYDBENUM
TIN
TITANIUM
VANADIUM
TOTAL NONCONVENTIONAL METALS
AMMONIA AS N
CHEMICAL OXYGEN DEMAND (COD)
CHLORIDE
FLUORIDE
SULFATE
TOTAL DISSOLVED SOLIDS
TOTAL KJELDAHL NITROGEN
TOTAL RECOVERABLE PHENOLICS
TOTAL PHOSPHORUS
TOTAL OTHER NONCONVENTIONALS
Industry Raw
Wastewater
Pollutant
Loading
(Ibs/yr)
588,000
1,500,000
56,500
8,720,000
1,560,000
134,000
73,200
269,000
37,400
16,500,000
2,210,000
1,640,000,000
122,000,000
4,240,000
86,400,000
1,670,000,000
4,110,000
134,000
25,100,000
3,560,000,000
Industry
Baseline
Pollutant
Loading
(Ibs/yr)
382,000
1,500,000
12,500
2,850,000
382,000
91,000
34,800
20,700
9,230
5,860,000
538,000
452,000,000
63,800,000
1,460,000
71,400,000
562,000,000
1,470,000
78,000
13,600,000
1,170,000,000
Option 1
Pollutant
Loading
(Ibs/yr)
43,900
1,440,000
4,780
126,000
15,500
68,900
16,100
14,000
8,250
1,840,000
264,000
6,500,000
28,500,000
211,000
45,600,000
181,000,000
625,000
34,800
229,000
263,000,000
Option 2
Pollutant
Loading
(Ibs/yr)
31,900
1,200,000
3,340
81,600
10,200
58,300
12,200
10,800
6,470
1,480,000
174,000
4,200,000
21,400,000
139,000
34,800,000
121,000,000
416,000
25,400
140,000
183,000,000
Option 3
Pollutant
Loading
(Ibs/yr)
3,180
120,000
334
8,150
1,020
5,830
1,220
1,070
646
148,000
17,400
421,000
2,140,000
13,900
3,470,000
12,100,000
41,700
2,530
14,000
18,200,000
Option I A
Pollutant
Loading
(Ibs/yr)
32,000
1,210,000
3,370
82,700
10,300
58,700
12,300
10,800
6,500
1,490,000
176,000
4,250,000
21,600,000
140,000
35,000,000
122,000,000
420,000
25,600
142,000
184,000,000
Option 2A
Pollutant
Loading
(Ibs/yr)
44,400
1,230,000
7,270
624,000
87,100
70,600
23,900
16,100
6,780
2,360,000
253,000
53,600,000
22,700,000
253,000
37,100,000
171,000,000
560,000
51,700
2,060,000
288,000,000
'Pollutant Irxarlinrrc f^
-------
Table 13-2 (Continued)
Summary of Pollutant Loadings by Option for MP&M Phase I Indirect Dischargers1
Pollutant
1,1,1-TRICHLOROETHANE
1,1-DICHLOROETHANE
4-CHLORO-3-METHYLPHENOL
ETHYLBENZENE
METHYLENE CHLORIDE
NAPHTHALENE
2-NITROPHENOL
PHENOL
BIS(2-ETHYLHEXYL)PHTHALATE
DI-N-BUTYL PHTHALATE
PHENANTHRENE
TETRACHLOROETHENE
TOLUENE
TOTAL PRIORITY ORGANICS
2-BUTANONE
2-METHYLNAPHTHALENE
2-PROPANONE
ALPHA-TERPINEOL
BENZOIC ACID
BENZYL ALCOHOL
Industry Raw
Wastewater
Pollutant
Loading
(Ibs/yr)
125,000
1,910
70,400
4,080
4,160,000
41,700
47,500
37,700
73,300
45,800
33,700
4,330
3,790
4,650,000
1,060,000
33,900
176,000
79,700
122,000
50,100
Industry
Baseline
Pollutant
Loading
(Ibs/yr)
41,800
1,550
48,900
3,650
131,000
21,900
25,700
24,500
51,000
30,200
19,100
4,230
2,430
406,000
791,000
19,700
97,000
54,900
63,900
34,000
Option 1
Pollutant
Loading
(Ibs/yr)
1,190
660
3,630
890
3,570
947
1,480
5,060
8,960
2,180
892
1,870
752
32,100
6,490
1,730
7,560
2,020
2,680
4,680
Option 2
Pollutant
Loading
(Ibs/yr)
1,090
574
2,470
693
2,280
679
1,000
3,800
6,580
1,510
614
1,630
593
23,500
3,910
1,170
5,000
1,340
1,800
3,250
Options
Pollutant
Loading
(Ibs/yr)
109
57.3
247
69.1
228
67.9
100
380
657
151
61.4
163
59.2
2,350
390
117
499
134
180
325
Option 1A
Pollutant
Loading
(Ibs/yr)
1,100
581
2,490
697
2,300
684
1,010
3,820
6,610
1,520
618
1,650
599
23,700
3,970
1,180
5,070
1,350
1,810
3,270
Option 2A
Pollutant
Loading
(Ibs/yr)
3,300
828
8,300
2,690
8,430
4,820
6,640
7,490
13,000
13,800
4,410
3,650
1,070
78,400
146,000
5,100
16,400
5,490
15,900
7,210
'Pollutant loadings for calcium, magnesium, and sodium
pH, and total alkalinity are not presented because they
are not presented in this table because these are typical wastewater treatment chemicals at MP&M sites. Pollutant loadings for acidity,
are used as performance parameters for chemical precipitation and settling systems.
-------
Table 13-2 (Continued)
Summary of Pollutant Loadings by Option for MP&M Phase I Indirect Dischargers1
Pollutant
HEXANOIC ACID
N-DECANE
N-DOCOSANE
N-DODECANE
N-EICOSANE
N-HEXACOSANE
N-HEXADECANE
N-OCTACOSANE
N-OCTADECANE
N-TETRACOSANE
N-TETRADECANE
N-TRIACONTANE
TOTAL NONCONVENTIONAL ORGANICS
Industry Raw
Wastewater
Pollutant
Loading
(Ibs/yr)
34,100
33,900
215,000
230,000
80,300
165,000
101,000
133,000
110,000
213,000
155,000
63,500
3,050,000
Industry
Baseline
Pollutant
Loading
(Ibs/yr)
21,000
19,300
121,000
127,000
43,400
93,200
70,600
74,000
76,000
119,000
113,000
36,300
1,970,000
Option 1
Pollutant
Loading
(Ibs/yr)
1,620
917
915
6,030
1,330
1,440
2,620
1,870
1,850
1,920
2,540
1,800
50,000
Option 2
Pollutant
Loading
Obs/yr)
1,070
627
594
4,010
909
974
1,710
1,240
1,220
1,290
1,660
1,200
33,000
Option3
Pollutant
Loading
(Ibs/yr)
107
62.7
59.3
401
90.9
97.4
171
124
122
129
166
120
3,300
Option 1A
Pollutant
Loading
ffbs/yr)
1,070
631
598
4,040
916
981
1,720
1,250
1,230
1,300
1,670
1,200
33,300
Option 2A
Pollutant
Loading
(IbS/yr)
4,890
4,550
25,100
29,200
10,400
19,800
8,560
16,600
12,000
25,800
7,110
8,480
368,000
OS
Source: MP&M Phase I Pollutant Loadings.
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Table 13-3
Summary of Pollutant Reductions by Option for MP&M Phase I Direct Dischargers1
Class of Pollutant
PRIORITY METALS
CYANIDE
OIL AND GREASE
TOTAL SUSPENDED SOLIDS
NONCONVENTIONAL METALS
OTHER NONCONVENTIONALS
PRIORITY ORGANICS
NONCONVENTIONAL ORGANICS
Industry Baseline
Pollutant Loading
dbs/yr)
557,000
3,840
18,200,000
2,590,000
634,000
96,400,000
8,940
68,600
Option 1
Pollutant
Reduction (Ibs/yr)
502,000
3,840
17,900,000
1,920,000
474,000
46,300,000
2,990
56,100
% Reduction
from Baseline
90
>99
99
74
75
48
33
82
Option 2, 1A, and
2A
Pollutant
Reduction (Ibs/yr)
517,000
3,840
18,000,000
2,220,000
501,000
64,900,000
5,080
61,600
% Reduction
from Baseline
93
>99
99
86
79
67
57
90
Option3
Pollutant
Reduction Ibs/yr
553,000
3,840
18,200,000
2,550,000
621,000
93,300,000
8,550
67,900
% Reduction
from Baseline
99
>99
>99
99
98
97
96
99
Source: MP&M Phase I Pollutant Loadings.
'Pollutant loadings for calcium, magnesium, and sodium are not presented in this table because these are typical wastewater treatment chemicals at MP&M sites. Pollutant loadings for acidity, pH,
and total alkalinity are not presented because they are used as performance parameters for chemical precipitation and settling systems.
-------
Table 13-4
Summary of Pollutant Reductions by Option for MP&M Phase I Indirect Dischargers1
Class of Pollutant
PRIORITY METALS
CYANIDE
OIL AND GREASE
TOTAL SUSPENDED
SOLIDS
NONCONVENTIONAL
METALS
OTHER
NONCONVENTIONALS
PRIORITY ORGANICS
NONCONVENTIONAL
ORGANICS
Industry
Baseline
Pollutant
Loading
dbs/yr)
6,100,000
170,000
170,000,000
17,700,000
5,860,000
1,170,000,000
406,000
1,970,000
Option 1
Pollutant
Reduction
dbs/yr)
5,850,000
170,000
169,000,000
14,500,000
4,020,000
903,000,000
374,000
1,920,000
%
Reduction
from
Baseline
96
>99
99
82
69
77
92
97
Option 2
Pollutant
Reduction
(Ibs/yr)
5,920,000
170,000
170,000,000
15,600,000
4,370,000
983,000,000
383,000
1,940,000
%
Reduction
from
Baseline
97
>99
>99
88
75
84
94
98
Option 3
Pollutant
Reduction
flbs/yr)
6,080,000
170,000
170,000,000
17,500,000
5,710,000
1,150,000,000
404,000
1,970,000
%
Reduction
from
Baseline
>99
>99
>99
99
97
98
99
>99
Option 1A
Pollutant
Reduction
fltos/yr)
5,920,000
170,000
170,000,000
15,600,000
4,370,000
982,000,000
383,000
1,940,000
%
Reduction
from
Baseline
97
>99
>99
88
75
84
94
98
Option 2A
Pollutant
Reduction
(Ibs/yr)
5,610,000
169,000
147,000,000
12,000,000
3,490,000
878,000,000
328,000
1,610,000
%
Reduction
from
Baseline
92
99
87
68
60
75
81
81
oo
Source: MP&M Phase I Pollutant Loadings.
'Pollutant loadings for calcium, magnesium, and sodium are not presented in this table because these are typical wastewater treatment chemicals at MP&M sites. Pollutant loadings for acidity, pH,
and total alkalinity are not presented because these are used as performance parameters for chemical precipitation and settling systems.
-------
Available Analytical
Data (with paired
flow and
production data)
\
Available
Data for E
Operation
Metal Typ
Combinat
f
Sampling
ach Unit
and
e
on
Calculation of Unit Operation PNPLs
Multiply by PNF
associated with
the sample or
PNPLs for Each
Average
duplicate and
multiple-day
PNPLs for Each
Average across
all sampled sites,
perform PNPL
PNPLs for Each
Metal Type and
Unit Operation
Combination
1
PNI- from samples ^^^^^^^^^^^^^^^ modeling ana
MP&M dcps PNPL transfers
Calculation of Industry Raw
Wastewater Pollutant Loadings
Calculation of Industry
Baseline Pollutant Loadings
Calculation of Option-Specific Industry
Pollutant Loadings and Reductions
ivide by PNFs
ar wastewater
treams at
ach model site
Wastewater stream
Concentrations for
Each Pollutant at
Each Model Site
|
Multiply by annual
flow for each
wastewater
stream at each
model site, scale
up to industry,
and sum across
all model sites
Industry Raw
Wastewater
Pollutant Loadings
Subtract scaled-
up pollutant
loads removed
Industry Baseline
Pollutant Loadings
by TIP at each
model site
Subtract scaled-up
pollutant loads
removed by each
MP&M Technology
Option
Option-Specific
Industry Pollutant
Loadings and
Reductions
Key:
PNPL
PNP
PNF
TIP
Production-normalized polluatant loading
Production-normalizing parameter
Production-normalized flow
Technology-in-place
Figure 13-1. Estimation of MP&M Pollutant Loadings and Reductions
-------
-------
14.0 NONWATER QUALITY IMPACTS
14.0 NONWATER QUALITY IMPACTS
Sections 304(b) and 306 of the Act require EPA to consider nonwater quality
environmental impacts (including energy requirements) associated with effluent
limitations guidelines and standards. In accordance with these requirements, EPA has
considered the potential impact of the proposed regulation on energy consumption, air
emissions, and solid waste generation. The Agency has also considered the impacts of
other ongoing EPA rulemaking efforts on Metal Products and Machinery (MP&M)
Phase I sites.
This regulation was reviewed by EPA personnel responsible for nonwater quality
environmental programs. To balance environmental impacts across all media and energy
use, the Agency has determined that the impacts identified below are justified by the
benefits associated with compliance with the limitations and standards.
14.1 Energy Requirements
EPA estimates that compliance with this regulation will result in a net increase in energy
consumption at MP&M Phase I sites. Estimates of energy usage by option are presented
below.
Option
Baseline (1989)
Option 1
Option 1A
Option 2
Option 2A
Option 3
Energy Required
(million kilowatt hrs/yr)
610
810
750
740
640
760
Source: MP&M Phase I Design and Cost Model Output.
Option 1, consisting solely of end-of-pipe treatment, requires the greatest energy usage.
Options 1A, 2, and 2A, which include in-process flow control and recycling technologies
for some or all sites, require less energy than Option 1. While the flow control and
recycling technologies require some energy, net energy consumption is reduced under
these options since the lower hydraulic loading reduces the end-of-pipe treatment energy
required. The additional end-of-pipe technology included in Option 3 (ion-exchange)
increases energy consumption from Option 2 to Option 3.
14-1
-------
14.0 NONWATER QUALITY IMPACTS
Approximately 2,805 billion kilowatt hours of electric power were generated in the
United States in 1990 (1). Additional energy requirements for Option 1 (which has the
greatest energy requirements of the four options) correspond to approximately 0.007% of
national requirements. The increase in energy requirements due to the implementation
of MP&M technologies will in turn cause an air emissions impact from the electric
power generation facilities. The increase in air emissions is expected to be proportional
to the increase in energy requirements, or approximately 0.007 percent.
14.2 Air Emissions Impacts
The Agency is developing National Emission Standards for Hazardous Air Pollutants
(NESHAPs) under Section 112 of the Clean Air Act (CAA) to address air emissions of
the hazardous air pollutants (HAPs) listed in Title III of the CAA Amendments of
1990 (CAAA). Current and upcoming NESHAPs that may potentially affect MP&M
sites are listed below.
• Chromium Emissions from Hard and Decorative Chromium
Electroplating and Chromium Anodizing Tanks - Proposed
December 16, 1993 and promulgated on January 25, 1995.
• Halogenated Solvent Cleaning - Proposed November 29, 1993, and
promulgated on December 2, 1994.
• Aerospace Manufacturing - Proposed June 6, 1994, and scheduled
for promulgation on July 31, 1995.
• Miscellaneous Metal Parts and Products (Surface Coating),
scheduled for promulgation November 15, 2000.
These NESHAPs will define maximum achievable control technology (MACT). Like
effluent guidelines, MACT standards are technology-based. The CAAA set maximum
control requirements on which MACT can be based for new and existing sources.
The use of chlorinated solvents in the MP&M industry can create a source of hazardous
emissions. The Agency believes this regulation will not affect the use of chlorinated
solvents in the MP&M industry. This regulation neither requires nor discourages the use
of aqueous cleaners in lieu of chlorinated solvents. EPA has recently initiated its
Significant New Alternatives Policy (SNAP) program which reviews chlorofluorocarbon
(CFC) substitutes stemming from the Montreal Protocol. In this program, EPA reviews
available data for CFC substitutes, and assesses the environmental impacts of the
substitutes. EPA published a final rulemaking for the SNAP program on March 18, 1994
(59 FR 13044) and plans to publish subsequent notices as determinations are made as to
the viability of the substitutes.
14-2
-------
14.0 NONWATER QUALITY IMPACTS
EPA is addressing emissions of volatile organic compounds (VOCs) from industrial
wastewater through a Control Techniques Guideline (CTG) for industrial wastewater
under Section 110 of the CAA (Title I of the 1990 CAAA). The MP&M industry is one
of several industries that would be covered by the industrial wastewater CTG. The
industrial wastewater CTG will provide guidance to states in recommending reasonably
available control technology (RACT) for VOC emissions from industrial wastewater at
sites located in areas failing to attain the National Ambient Air Quality Standard for
ozone.
The Agency believes that the in-process and end-of-pipe technologies included in the
technology options for this regulation do not generate significant air emissions.
14.3
Solid Waste Generation
Solid waste generated at MP&M sites includes hazardous and nonhazardous wastewater
treatment sludge as well as waste oil removed in wastewater treatment. EPA estimates
that compliance with this regulation will result in a decrease in wastewater treatment
sludge and an increase in waste oil generated at MP&M Phase I sites.
EPA estimates that MP&M Phase I sites generated 33 million gallons of wastewater
treatment sludge and 8.1 million gallons of waste oil in 1989 from the treatment of
wastewater. The amount of wastewater treatment sludge and waste oil expected to be
generated in each of the technology options is presented in the table below.
Option
Baseline (1989)
Option 1
Option 1A
Option 2
Option 2A
Option 3
Wastewater Treatment Sludge
Generated (gal/yr)
33,000,000
31,000,000
21,000,000
21,000,000
22,000,000
21,000,000
Waste Oil Generated
(gal/yr)
8,100,000
38,000,000
36,000,000
36,000,000
34,000,000
36,000,000
Source: MP&M Design and Cost Model Output.
As shown in this table, wastewater treatment sludge generation decreases from baseline
to Option 1 (which consists of end-of-pipe treatment without in-process flow control).
The net decrease is attributed to the fact that Option 1 includes sludge dewatering,
which may result in a significant decrease in sludge generation for sites that have
chemical precipitation and sedimentation technologies without sludge dewatering in place
14-3
-------
14.0 NONWATER QUALITY IMPACTS
at baseline. Sludge reduction is not expected at sites which already have sludge
dewatering in the baseline. An increase of sludge is expected to occur at sites which do
not have treatment technology in place but are expected to install treatment under the
MP&M options.
The sludge reduction from Option 1 to Options 1A, 2, and 2A is attributed to the water
conservation and pollution prevention technologies included in Options 1A, 2, and 2A.
EPA expects these technologies to result in sludge reduction for the following reasons:
• In-process metals recovery for electroplating rinses, recycling of
coolants, and recycling of paint curtains reduce the mass of metal
pollutants in treatment system influent streams, which in turn
reduces the amount of sludge generated during metals removal;
• Bath maintenance practices included in Options 1A, 2, and 2A
reduce the mass of metal pollutants discharged to treatment, which
in turn reduces the amount of sludge generated during metals
removal; and
• Water conservation technologies included in Options 1A, 2 and 2A
reduces the discharge mass of metals present in the source water to
a site (e.g., calcium, sodium), which in turn reduces the amount of
sludge generated during metals removal.
EPA does not expect Option 3 to result in additional sludge generation or reduction over
Options 1A, 2, and 2A.
Sludges generated at MP&M sites are often determined to be hazardous under the
Resource Conservation and Recovery Act (RCRA) as either a listed or characteristic
hazardous waste based on the following information:
• If the site performs electroplating operations, and this wastewater is
mixed with the other wastewater treated on site, the resulting sludge
is a listed hazardous waste F006 (40 CFR 260.11), or
• If the sludge or waste oil from wastewater treatment exceeds the
standards for the Toxicity Characteristic Leaching Procedure (i.e. is
hazardous), or exhibits other RCRA-defined hazardous
characteristics (i.e., reactive, corrosive, or flammable) it is
considered a characteristic hazardous waste. (40 CFR 261.24).
Additional federal, state, and local regulations may result in MP&M sludges being
classified as hazardous wastes.
14-4
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14.0 NONWATER QUALITY IMPACTS
EPA is addressing emissions of volatile organic compounds (VOCs) from industrial
wastewater through a Control Techniques Guideline (CTG) for industrial wastewater
under Section 110 of the CAA (Title I of the 1990 CAAA). The MP&M industry is one
of several industries that would be covered by the industrial wastewater CTG. The
industrial wastewater CTG will provide guidance to states in recommending reasonably
available control technology (RACT) for VOC emissions from industrial wastewater at
sites located in areas failing to attain the National Ambient Air Quality Standard for
ozone.
The Agency believes that the in-process and end-of-pipe technologies included in the
technology options for this regulation do not generate significant air emissions.
14.3
Solid Waste Generation
Solid waste generated at MP&M sites includes hazardous and nonhazardous wastewater
treatment sludge as well as waste oil removed in wastewater treatment. EPA estimates
that compliance with this regulation will result in a decrease in wastewater treatment
sludge and an increase in waste oil generated at MP&M Phase I sites.
EPA estimates that MP&M Phase I sites generated 33 million gallons of wastewater
treatment sludge and 8.1 million gallons of waste oil in 1989 from the treatment of
wastewater. The amount of wastewater treatment sludge and waste oil expected to be
generated in each of the technology options is presented in the table below.
Option
Baseline (1989)
Option 1
Option 1A
Option 2
Option 2A
Option 3
Wastewater Treatment Sludge
Generated (gal/yr)
33,000,000
31,000,000
21,000,000
21,000,000
22,000,000
21,000,000
Waste Oil Generated
(gal/yr)
8,100,000
38,000,000
36,000,000
36,000,000
34,000,000
36,000,000
Source: MP&M Design and Cost Model Output.
As shown in this table, wastewater treatment sludge generation decreases from baseline
to Option 1 (which consists of end-of-pipe treatment without in-process flow control).
The net decrease is attributed to the fact that Option 1 includes sludge dewatering,
which may result in a significant decrease in sludge generation for sites that have
chemical precipitation and sedimentation technologies without sludge dewatering in place
14-3
-------
14.0 NONWATER QUALITY IMPACTS
at baseline. Sludge reduction is not expected at sites which already have sludge
dewatering in the baseline. An increase of sludge is expected to occur at sites which do
not have treatment technology in place but are expected to install treatment under the
MP&M options.
The sludge reduction from Option 1 to Options 1A, 2, and 2A is attributed to the water
conservation and pollution prevention technologies included in Options 1A, 2, and 2A.
EPA expects these technologies to result in sludge reduction for the following reasons:
• In-process metals recovery for electroplating rinses, recycling of
coolants, and recycling of paint curtains reduce the mass of metal
pollutants in treatment system influent streams, which in turn
reduces the amount of sludge generated during metals removal;
• Bath maintenance practices included in Options 1A, 2, and 2A
reduce the mass of metal pollutants discharged to treatment, which
in turn reduces the amount of sludge generated during metals
removal; and
• Water conservation technologies included in Options 1A, 2 and 2A
reduces the discharge mass of metals present in the source water to
a site (e.g., calcium, sodium), which in turn reduces the amount of
sludge generated during metals removal.
EPA does not expect Option 3 to result in additional sludge generation or reduction over
Options 1A, 2, and 2A.
Sludges generated at MP&M sites are often determined to be hazardous under the
Resource Conservation and Recovery Act (RCRA) as either a listed or characteristic
hazardous waste based on the following information:
• If the site performs electroplating operations, and this wastewater is
mixed with the other wastewater treated on site, the resulting sludge
is a listed hazardous waste F006 (40 CFR 260.11), or
• If the sludge or waste oil from wastewater treatment exceeds the
standards for the Toxicity Characteristic Leaching Procedure (i.e. is
hazardous), or exhibits other RCRA-defined hazardous
characteristics (i.e., reactive, corrosive, or flammable) it is
considered a characteristic hazardous waste. (40 CFR 261.24).
Additional federal, state, and local regulations may result in MP&M sludges being
classified as hazardous wastes.
14-4
-------
14.0 NONWATER QUALITY IMPACTS
Based on information collected during site visits and sampling episodes, the Agency
believes that some of the solid waste generated at MP&M sites would not be classified
as hazardous. However, for the purpose of compliance cost estimation, the Agency
assumed that all solid waste generated as a result of the technology options would be
hazardous.
The increase in waste oil generation from baseline to Option 1 is attributed to removal
of oil from MP&M wastewaters prior to discharge to POTWs or surface waters.
Option 1 includes oil/water separation to remove oil from oil/bearing wastewaters. The
waste oil is usually either recycled on site or off site, or contract hauled for disposal as
either a hazardous or nonhazardous waste. The increase of waste oil generation reflects
a transfer of oil from the wastewater to a more concentrated waste oil, and does not
reflect an increase in overall oil generation at MP&M Phase I sites. For the purpose of
compliance cost estimation, EPA assumed that all waste oil was contract hauled for
disposal; however, EPA expects that some of the waste oil can be recycled either on site
or off site.
The decrease in waste oil generation from Option 1 to Options 1A, 2, and 2A is
attributed to the 80% reduction of coolant discharge using the recycling technology
included in Options 1A, 2, and 2A. This system recovers and recycles oil/bearing
machining coolants at the source, reducing the generation of spent coolant. Coolant
recycling saves approximately 8.7 million gallons of water-soluble coolant (assumed to be
5% oil in water) at Option 1A, 9.8 million gallons at Option 2 and 8.7 million gallons at
Option 2A. EPA does not expect Option 3 to result in additional waste oil generation or
reduction over Option 2.
The in-process technologies of ion-exchange and electrolytic recovery provide the
pollution prevention benefits of reclaiming on estimated 1.7 million pounds of metal
annually at Options 1A, 2, and 2A. This reuse reduces the solid waste generation at the
end-of-pipe for the treatment of wastewater from operations using these technologies.
14-5
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14.0 NONWATER QUALITY IMPACTS
14.4 References
1. Steam. Its Generation and Uses. 4th Ed. (Babcock & Wilcox, Ed Stutz &
Kitto, Barberton, Ohio, 1992).
14-6
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15.0 EFFLUENT LIMITATIONS AND STANDARDS
15.0 EFFLUENT LIMITATIONS AND STANDARDS
This section presents the proposed Metal Products and Machinery (MP&M) Phase I
effluent limitations guidelines and standards for each regulatory level of control required
by the Clean Water Act. These levels of control are discussed in Section 2.0. The
proposed limitations and standards are based on the technologies included in Option 2A,
as discussed in Section 10.0. The proposed MP&M effluent limitations guidelines and
standards consist of mass-based limitations for all direct dischargers, for all new indirect
dischargers, and for existing indirect dischargers with greater than or equal to one
million gallons per year of process wastewater discharge. Existing indirect dischargers
with less than one million gallons per year of process wastewater discharge are exempt
from the proposed regulation. Direct dischargers are sites that discharge wastewater to a
surface water. Indirect dischargers are sites that discharge wastewater to a publicly-
owned treatment works (POTW).
Section 15.1 presents a discussion of the technology option used as a basis for the
effluent limitations and standards. Section 15.2 presents the numerical concentration-
based limitations and standards upon which the mass-based standards should be based.
Sections 15.3 through 15.6 discuss each of the regulatory levels of control.
15.1 Technology Option
The proposed limitations and standards are based on the technologies included in
Option 2A. The technology basis for Option 2A is end-of-pipe treatment using chemical
precipitation and sedimentation, used in conjunction with flow reduction and pollution
prevention technologies. Option 2A also includes the following preliminary treatment
steps: oil/water separation through chemical emulsion breaking and either skimming or
coalescing; cyanide destruction through alkaline chlorination; chemical reduction of
hexavalent chromium; chemical reduction of chelated metals; and contract hauling of
organic solvent-bearing wastewaters. These preliminary treatment technologies are
applied as necessary based on wastewater characteristics.
Option 2A includes the following in-process pollution prevention and water conservation
technologies:
• Flow reduction using flow restrictors, conductivity meters, and/or
timed rinses, for all flowing rinses, plus countercurrent cascade
rinsing for all flowing rinses;
• Flow reduction using bath maintenance for all other process water-
discharging operations;
• Centrifugation and 100% recycling of painting water curtains;
15-1
-------
15.0 EFFLUENT LIMITATIONS AND STANDARDS
• Centrifugation and pasteurization to extend the life of water-soluble
machining coolants, reducing discharge volume by 80 percent; and
• In-process metals recovery with ion exchange followed by electrolytic
recovery of the cation regenerants for selected electroplating rinses.
This includes first-stage drag-out rinsing with electrolytic metal
recovery.
The technologies included in Option 2A are discussed in detail in Section 10.0.
The effluent limitations and standards are based on the technologies discussed above.
However, these technologies are not mandated under effluent guidelines and
pretreatment standards. Sites regulated by this rule are required to meet the discharge
limitations but are not required to use the technologies discussed above.
15.2 Numerical Limitations and Standards
For all direct dischargers, new indirect dischargers, and existing indirect dischargers
discharging greater than or equal to one million gallons of process wastewater per year,
EPA will require permit writers to develop mass-based limitations based on the proposed
concentration-based limitations. Existing indirect dischargers discharging less than one
million gallons of process wastewater per year are exempt from the proposed regulation.
Table 15-1 presents the proposed concentration-based limitations. These limitations
were developed from the MP&M sampling data using the data editing and statistical
procedures discussed in Section 11.0.
EPA developed the proposed MP&M Phase I effluent limitations guidelines and
standards as concentration-based limitations which must be converted to mass-based
limitations. Mass-based limitations should be developed using the MP&M flow guidance
presented in Section 16.0. If mass-based limitations have not been developed as
required, the source shall achieve discharges not exceeding the concentration limitations
listed in the proposed regulation.
To fully implement the mass-based permits, it is important for Control Authorities to
issue permits in a timely manner. Dischargers are required under the General
Pretreatment Regulations (40 CFR 403) to provide, among other things, Baseline
Monitoring Reports. The Agency expects Control Authorities to place a priority on
issuing needed mass-based permits, and those permits should be issued within one year
after the Baseline Monitoring Report deadline. Control Authorities that do not meet
these permitting timelines may not be in compliance with their pretreatment programs
under 40 CFR 123.45.
EPA recommends that, for sites with pollution prevention and water conservation
technologies in place that are equivalent to those included in Option 2A, permit writers
15-2
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15.0 EFFLUENT LIMITATIONS AND STANDARDS
use historical flow as a basis for converting the proposed concentration-based limitations
to mass-based. For sites without these types of technologies in place, EPA recommends
that permit writers do not use historical flow, but use other tools listed in Section 16.0
(e.g., measuring production through unit operations, measuring the concentration of total
dissolved solids (TDS) in rinse waters) to convert the proposed concentration-based
limitations to mass-based. This approach encourages sites to implement good water use
practices and investigate and install pollution prevention and water conservation
technologies.
15.3 Best Practicable Control Technology Currently Available (BPT)
The proposed MP&M Phase I BPT effluent limitations guidelines are based on the
average of the best existing performance by MP&M Phase I sites of various sizes, ages,
and unit processes for control of pollutants. The BPT limitations apply to the estimated
1,895 MP&M Phase I sites that discharge process wastewater to a surface water. The
following table presents the estimated amount of pollutants discharged annually from
direct dischargers.
Annual Pollutant Discharges by Direct Dischargers
Pollutant Parameter
Estimated Mass of Pollutant
Discharged Annually
(thousands of pounds)
Priority Metal Pollutants
Nonconventional Metal Pollutants (a)
Priority Organic Pollutants
Nonconventional Organic Pollutants
Cyanide
Oil and Grease
Total Suspended Solids
557
634
8.94
68.6
3.84
18,200
2,590
Source: EPA MP&M pollutant loading estimates
a - Nonconventional Metal Pollutants do not include calcium, magnesium, and sodium, which are used as
treatment chemicals at MP&M sites.
In establishing the proposed BPT effluent limitations guidelines, EPA considered the
category-wide cost of achieving effluent reductions in relation to the effluent reduction
benefits. EPA estimates that implementation of Option 2A technologies will require, for
direct dischargers, a capital cost of $63.0 million (1994 $), which will require an
annualized cost of $18 million. As a result of this regulation, EPA estimates that 18 sites
may close with an accompanying job loss of 158 full-time employees. EPA estimates that
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compliance activities may generate annual labor requirements which could more than
offset these job losses. The proposed BPT limitations will remove annually an estimated
20 million pounds of conventional pollutants (total suspended solids and oil and grease),
1 million pounds of metal pollutants and cyanide, and 66,700 pounds of organic
pollutants. The following table presents the estimated amount of pollutant discharges
after implementation of BPT.
Estimated Annual Pollutant Discharges
by Direct Dischargers after Implementing BPT Technologies
Pollutant Parameter
Estimated Mass of Pollutant
Discharged Annually
(thousands of pounds)
Priority Metal Pollutants
Nonconventional Metal Pollutants (a)
Priority Organic Pollutants
Nonconventional Organic Pollutants
Cyanide
Oil and Grease
Total Suspended Solids
40.5
133
3.86
7.02
< 0.001
153
364
Source: EPA MP&M pollutant loading estimates
a - Nonconventional Metal Pollutants do not include calcium, magnesium, and sodium, which are used as
treatment chemicals at MP&M sites.
The proposed BPT limitations apply to all of the pollutants listed in Table 15-1. These
include priority metal pollutants, conventional pollutants, and nonconventional metal
pollutants. EPA developed the proposed BPT effluent limitations guidelines as
concentration-based limitations which must be converted to mass-based limitations.
Mass-based limitations should be developed using the MP&M flow guidance presented
in Section 16.0. If mass-based limitations have not been developed as required, the
source shall achieve discharges not exceeding the concentration limitations listed in the
regulation.
EPA identified 24 metal types processed at MP&M Phase I sites. Because EPA did not
have sufficient data to set limitations for all of these metal types, EPA is regulating
aluminum and iron as indicator metals for removal of nonregulated metals that may be
processed at MP&M sites. Aluminum is most effectively removed in chemical
precipitation and sedimentation systems at a pH between 7.5 and 8 standard units, while
iron is most effectively removed at a pH of approximately 10.5 standard units. Most of
the metals present in MP&M wastewaters are effectively removed in this pH range.
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Therefore, removal of aluminum and iron will indicate effective removal of other metal
types.
EPA is using oil and grease as an indicator for monitoring for organic pollutants that
have the potential to be present in MP&M Phase I wastewaters. EPA is using oil and
grease as an indicator since most of the organic pollutants detected in MP&M
wastewaters during the MP&M Phase I sampling program are more soluble in oil than in
water, and as such would partition to the oil layer. Thus, removal of oil and grease will
result in significant removal of these pollutants. Data for oil/water separation systems
collected during the MP&M Phase I sampling program show removals between 63 and
90 percent for organic pollutants across the oil/water separation systems. These data
support the conclusion that the organic pollutants will partition to the oil layer. In
addition, most of the organic pollutants detected in MP&M wastewaters are insoluble in
water, further supporting that these pollutants will partition to the oil layer.
EPA considered establishing limitations for total toxic organics (TTO), which would
reflect the sum of concentrations achieved for several specific organic pollutants
identified during the MP&M sampling program. However, because of the diversity in
the types of organic-bearing solutions (cleaners, coolants, paints, etc.) used in the MP&M
industry, as well as the current industry trends in identifying substitutes for organic
solvent degreasing, EPA did not have sufficient analytical data to identify and regulate
all organic pollutants in use at MP&M sites. Therefore, EPA did not use TTO as an
approach to controlling organic pollutant discharges.
EPA also considered establishing limitations for lead, since lead is known to have several
adverse human health effects. Although lead was analyzed for in nearly all samples
collected during the development of the MP&M Phase I effluent guidelines, lead was
rarely found at concentrations above 0.1 milligrams per liter in raw wastewater prior to
treatment. The majority of lead data were nondetects or detects at low concentrations.
Therefore, EPA has not proposed a lead limitation.
15.4 Best Conventional Pollutant Control Technology (BCT)
BCT limitations control discharges of conventional pollutants from existing direct
dischargers. BCT is not an additional limitation, but replaces BAT for the control of
conventional pollutants. EPA evaluates the reasonableness of BCT candidate
technologies (those that are technologically feasible) by applying a two-part cost test:
(1) The POTW test; and
(2) The industry cost-effectiveness test.
In the POTW test, EPA calculates the cost per pound of conventional pollutant removed
by industrial dischargers in upgrading from BPT to a BCT candidate technology, and
then compares this cost to the cost per pound of conventional pollutant removed in
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15.0 EFFLUENT LIMITATIONS AND STANDARDS
upgrading POTWs from secondary treatment. The upgrade cost to industry must be less
than the POTW benchmark of $0.25 per pound (in 1976 dollars).
In the industry cost-effectiveness test, the ratio of the incremental BPT to BCT cost
divided by the BPT cost for the industry must be less than 1.29 (i.e., the cost increase
must be less than 29 percent).
EPA applied the BCT cost test to the use of multimedia filtration technology as a means
to reduce loadings of total suspended solids (TSS). The MP&M Phase I sites were
divided into three flow categories for this analysis: low flow (less than 10,000 gallons per
year); medium flow (between 10,000 gallons per year and 1,000,000 gallons per year);
and high flow (greater than 1,000,000 gallons per year). For each of these three flow
categories, a representative site was selected for which EPA had estimated the costs of
installing the BPT technologies.
EPA evaluated the costs of installing a multimedia filter to remove an estimated
additional 45 percent of the TSS discharged after chemical precipitation and
sedimentation. This estimated removal reflects the reduced TSS concentrations achieved
when filters are used at MP&M Phase I sites. The cost per pound removed in the high
flow case was $28 per pound of TSS (in 1976 dollars); the cost per pound removed in the
medium flow case was $131 per pound of TSS (1976 dollars); and, the cost per pound
removed in the low flow case was $813 per pound of TSS (1976 dollars). All of these
cases exceed the $0.25 per pound (in 1976 dollars) POTW cost test value. Because these
costs exceed the POTW benchmark, the first part of the cost test fails; therefore, the
second part of the test was not performed. Because multimedia filtration does not pass
the cost test, BCT limitations for MP&M Phase I are proposed to be set equal to BPT
limitations.
15.5 Best Available Technology Economically Achievable (BAT)
EPA developed the proposed MP&M Phase I BAT effluent limitations guidelines for
five priority pollutant metals, cyanide, and two nonconventional pollutant metals. EPA
also developed proposed BAT limitations for oil and grease as an indicator for the
following organic pollutants: 2-methylnaphthalene, 2-propanone, N-octadecane, and N-
tetradecane. Oil and grease is also used as an indicator for additional organic pollutants
that may be present in MP&M Phase I wastewaters. The proposed BAT limitations for
these pollutants are the same as those for BPT. The pollutant removals, costs, and
economic impacts of BAT are expected to be the same as for BPT.
Like BPT, EPA developed the proposed BAT effluent limitations guidelines as
concentration-based limitations which must be converted to mass-based limitations. The
proposed concentration-based limitations are presented in Table 15-1. Mass-based
limitations should be developed using the MP&M flow guidance presented in Section
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16.0. If mass-based limitations have not been developed as required, the source shall
achieve discharges not exceeding the concentration limitations listed in the regulation.
15.6 Pretreatment Standards for Existing Sources (PSES)
The proposed MP&M Phase I 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 (POTWs). The proposed MP&M Phase I PSES apply to
existing indirect dischargers with annual process wastewater discharge rates greater than
or equal to one million gallons. Existing indirect dischargers with an annual process
wastewater discharge of less than one million gallons are exempt from the proposed
regulation. EPA estimates that 1,998 MP&M Phase I sites will be regulated under
PSES, while 6,708 will be exempt. Sites regulated under PSES discharge approximately
18 billion gallons of process wastewater per year. The following table presents the
estimated amount of pollutant discharges from sites regulated under PSES.
Annual Pollutant Discharges by Sites Regulated Under PSES
Pollutant Parameter
Estimated Mass of Pollutant
Discharged Annually
(thousands of pounds)
Priority Metal Pollutants
Nonconventional Metal Pollutants (a)
Priority Organic Pollutants
Nonconventional Organic Pollutants
Cyanide
5,780
4,910
351
1,640
169
Source: EPA MP&M pollutant loading estimates
a - Nonconventional Metal Pollutants do not include calcium, magnesium, and sodium, which are used as
treatment chemicals at MP&M sites.
EPA estimates that the exempt sites discharge approximately 0.74 billion gallons of
process wastewater per year. The following table presents the estimated amount of
pollutant discharges from the sites exempted from PSES.
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Annual Pollutant Discharges by Sites Exempt From PSES
Pollutant Parameter
Estimated Mass of Pollutant
Discharged Annually
(thousands of pounds)
Priority Metal Pollutants
Nonconventional Metal Pollutants (a)
Priority Organic Pollutants
Nonconventional Organic Pollutants
Cyanide
325
947
55.7
336
1.30
Source: EPA MP&M pollutant loading estimates
a - Nonconventional Metal Pollutants do not include calcium, magnesium, and sodium, which are used as
treatment chemicals at MP&M sites.
The MP&M Phase I sites annually discharging less than one million gallons of process
wastewater represent 77% of the number of Phase I indirect dischargers, but only
generate 4% of the wastewater and 10% of the baseline pollutant loading from indirect
dischargers. Therefore, EPA believes that the costs of regulating existing indirect
discharging MP&M Phase I sites annually discharging less than one million gallons of
process wastewater do not justify the potential pollutant reduction achieved by
regulation.
As discussed in Section 8.0, EPA determined which pollutants to regulate in PSES on the
basis of whether or not the pollutants pass through, interfere with, or are incompatible
with the operation of POTWs (including interference with sludge practices). The Agency
evaluated pollutant pass-through by comparing the percentage of pollutant removed by
well-operated POTWs with secondary treatment with the percentage removed by BAT
technology applied by direct dischargers. Based on this analysis, EPA developed PSES
for five priority pollutant metals, cyanide, and two nonconventional pollutant metals.
EPA also developed PSES for oil and grease as an indicator for monitoring for organic
.pollutants that have the potential to be present in MP&M wastewaters. The proposed
PSES for these pollutants are listed in Table 15-1.
EPA estimates that PSES will require a capital cost of $351 million (1994 $), which will
require an annualized cost of $185 million. As a result of this regulation, EPA estimates
that 7 sites may close with an accompanying job loss of 540 full-time employees. EPA
estimates that compliance activities may generate annual labor requirements which could
more than offset these losses. The PSES limitations will remove annually an estimated 9
million pounds of metal pollutants and cyanide, and 2 million pounds of organic
pollutants. The following table presents the estimated amount of pollutant discharges
after implementation of PSES.
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Estimated Annual Pollutant Discharges
by Indirect Dischargers after Implementing PSES
Pollutant Parameter
Estimated Mass of Pollutant
Discharged Annually
(thousands of pounds)
Priority Metal Pollutants
Nonconventional Metal Pollutants (a)
Priority Organic Pollutants
Nonconventional Organic Pollutants
Cyanide
497
2,360
78.4
368
1.31
Source: EPA MP&M pollutant loading estimates
a - Nonconventional Metal Pollutants do not include calcium, magnesium, and sodium, which are used as
treatment chemicals at MP&M sites.
15.7 New Source Performance Standards (NSPS) and Pretreatment Standards
for New Sources (PSNS)
NSPS and PSES are established to control the discharge of pollutants from new sources.
The same technologies discussed for BAT and PSES are available as the basis for NSPS
and PSNS. Option 2A was the selected option for BAT and for large flow PSES. The
only higher technology option identified by EPA was Option 3, which includes end-of-
pipe ion exchange with ninety percent process water reuse. Since new sites have the
potential to install this technology more cost effectively than existing sources, Option 3
was considered for NSPS and PSNS. EPA did not select Option 3 technology as the
basis for NSPS and PSNS because the costs do not justify the removals achieved.
Therefore, NSPS and PSNS for MP&M Phase I are based on Option 2A technologies
identified above.
EPA developed the proposed NSPS and PSNS as concentration-based limitations which
must be converted to mass-based limitations for all new sources. The proposed
concentration-based limitations are presented in Table 15-1. Mass-based limitations
should be developed using the MP&M flow guidance presented in Section 16.0. If mass-
based limitations have not been developed as required, the source shall achieve
discharges not exceeding the concentration limitations listed in the regulation.
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Table 15-1
MP&M Phase I Concentration-Based Limitations
Pollutant or
Pollutant Parameter
Aluminum (T)(i)
Cadmium (T)(i)
Chromium (T)(i)
Copper (T)(l)
Iron (T)(l)
Nickel (T)(i)
Zinc (T)(i)
Cyanide (T)(i)
Oil and Grease (2)
Total Suspended Solids (3)
pH
Maximum for Any
One Day
(milligrams/liter)
1.4
0.7
0.3
1.3
2.4
1.1
0.8
0.03
35
73
(4)
Monthly Average -
Shall Not Exceed
(milligrams/liter)
1.0
0.3
0.2
0.6
1.3
0.5
0.4
0.02
17
36
(4)
Source: MP&M Technology Effectiveness Concentration (TEC) database.
(1) These concentrations apply to BPT, BAT, PSES, NSPS, and PSNS.
(2) These concentrations apply to all levels of regulatory control. Oil and grease is proposed as an indicator
for organic pollutants.
(3) These concentrations apply to BPT, BCT, and NSPS.
(4) Within 6.0 to 9.0 standard units. This applies to BPT, BCT, and NSPS
(T) Total (e.g., total aluminum, total cadmium, total cyanide).
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16.0 PERMITTING GUIDANCE
This section provides guidance to permit writers in implementing the Metal Products and
Machinery (MP&M) Phase I effluent guidelines. The MP&M Phase I category covers
sites that generate wastewater while processing metal parts, metal products, and
machinery, and includes operations performed during manufacturing, assembly,
rebuilding, repair, and maintenance. Phase I covers sites processing products in any of
the following seven industrial sectors: aerospace, aircraft, electronic equipment,
hardware, mobile industrial equipment, ordnance, and stationary industrial equipment.
A site is considered to be included in a sector if any of the products processed at the site
are used within that sector. Section 3.0 presents examples of the MP&M Phase I
applicability.
As discussed in Section 15.0, the MP&M Phase I effluent limitations guidelines and
standards consist of mass-based limitations for all direct dischargers, for all new indirect
dischargers, and for existing indirect dischargers with greater than or equal to one
million gallons per year of process wastewater discharge. Existing indirect dischargers
with less than one million gallons process wastewater discharge are exempt from this
regulation. Direct dischargers are sites that discharge wastewater to a surface water.
Indirect dischargers are sites that discharge wastewater to a publicly-owned treatment
works (POTW). EPA requires permit writers to develop mass-based limitations based
on the proposed concentration-based limitations. Concentration-based limitations should
be converted to mass-based limitations using the flow guidance provided in this section.
Table 15-1 presents the concentration-based limitations.
The MP&M Phase I effluent limitations are based on a technology train consisting of in-
process pollution prevention and flow reduction technologies followed by end-of-pipe
treatment. The in-process technologies include flow reduction for all unit operations;
countercurrent cascade rinsing for flowing rinses; ion exchange and electrolytic recovery
for certain electroplating rinses; at-the-source machine coolant recycling; and at-the-
source paint curtain recycling. The end-of-pipe treatment consists of chromium
reduction, cyanide destruction, oil/water separation, chelated metals treatment, and
chemical precipitation and settling. Section 10.0 presents a detailed discussion of this
technology train. Sites do not have to install this technology train to comply with the
MP&M effluent guidelines; this train was used solely as the basis for developing the
limits. Sites can use any technology as long as the limits are achieved.
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16.0 PERMITTING GUIDANCE
Section 16.1 provides basic guidance on implementing the MP&M Phase I effluent
guidelines. Sections 16.2 through 16.5 present flow guidance for the following major
wastewater-generating unit operations performed at MP&M sites, respectively:
• Surface treatment rinsing operations (e.g., acid and alkaline
treatment rinsing, electroplating rinsing, anodizing rinsing, and
chemical conversion coating rinsing);
• Machining operations;
• Painting operations; and
• Cleaning operations.
These operations generate approximately 75% of the wastewater generated by MP&M
Phase I sites. EPA estimates that 9,075 of the estimated 10,601 MP&M Phase I
wastewater-discharging sites perform one or more of these operations. EPA also
estimates that most of the remaining 1,526 sites are indirect discharges with less than one
million gallons of annual process wastewater discharge, and will be exempt from the
regulation. For sites not addressed by this flow guidance, EPA recommends that permit
writers use best professional judgment (BPJ) to develop the flow basis for converting the
concentration-based limits to mass-based limits.
16.1 Implementing the MP&M Phase I Effluent Guidelines
For all direct dischargers, all new indirect dischargers, and existing indirect dischargers
with one million gallons or greater of annual process wastewater discharge, EPA requires
permit writers to develop mass-based limitations based on the proposed concentration-
based limitations. Existing indirect dischargers with less than one million gallons of
annual process wastewater discharge are exempt from this regulation. The flow guidance
provided in this document is being provided by EPA to assist permit writers in
developing mass-based limits. Figure 16-1 presents a flow chart that summarizes the
MP&M Phase I permitting process.
Indirect dischargers are sites discharging process wastewater to a publicly owned
treatment works (POTW); direct dischargers are sites discharging process wastewater to
a surface water. Process wastewater is defined as any water that, during manufacturing,
rebuilding, or maintenance, comes into direct contact with or results from the production
or use of any raw materials, intermediate product, finished product, by-product, or waste
product. Noncontact cooling water is not considered a process wastewater.
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16.1.1 Assessment of Water Use Practices
Permit writers can use the site's historical flow, unit operation-specific production-
normalized flows (flow per unit of production), or other tools available to the permit
writer to develop a flow basis to convert the concentration-based limitations to mass-
based limitations. The Agency recommends that permit writers use historical data only
when a site has demonstrated pollution prevention and water conservation practices in
place (e.g., on-demand countercurrent cascade rinses, in-process metal recovery, recycling
of machining coolants) for unit operations contributing the majority of the flow from the
site. Examples of common pollution prevention and water conservation practices
applicable to the major wastewater-generating MP&M operations are summarized in
Sections 16.2 through 16.5. Additional examples are presented in Section 9.0. Sections
16.2 through 16.5 also provide guidance for assessing the performance of these practices
at MP&M Phase I sites. Unit operations typically contributing the majority of the flow
from a site are: cleaning solutions and rinses (e.g., alkaline treatment solutions and
rinses, acid treatment solutions and rinses); surface finishing rinses (e.g., electroplating
rinses, anodizing rinses, chemical conversion coating rinses); machining operations; and
painting operations.
16.1.2 Use of Historical Flow in Developing Mass-Based
Limitations
For a site with pollution prevention and water conservation practices in place, the
Agency recommends that the permit writer use the site's historical flow rate to convert
the concentration-based limitations to mass-based limitations. In this case, the permit
writer would multiply the site's historical process wastewater discharge flow rate by the
concentration-based limitations to calculate mass-based limitations. Estimation of a site's
historical process wastewater discharge flow rate is discussed below. Linking the use of
historical flow rate data to pollution prevention and water conservation practices reduces
the opportunity for dilution to achieve concentration limitations. This approach also
encourages sites to evaluate existing and potential pollution prevention and water
conservation opportunities.
Historical flow should be calculated as a reasonable estimate of the actual long-term
discharge flow rate from a site. For example, the normal daily average process
wastewater flow rate during a representative period of time (e.g., one to three years),
could be considered a historical flow rate. These average flows could be based on a
single year's data; however, if available, multiple years' data are preferable to obtain a
representation of annual average flow. Guidance for determining appropriate process
wastewater flow rate is presented in several documents published by the EPA Office of
Wastewater Enforcement and Compliance, Washington, DC: "Guidance Manual for the
Use of Production-Based Pretreatment Standards and the Combined Wastestream
Formula," 1985 (NTIS Order No. PB92-114438) and "Training Manual for NPDES
Permit Writers," 1993 (EPA 833-B-93-003).
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16.1.3 Use of Flow Guidance in Developing Mass-Based Limitations
When sites do not have pollution prevention and water conservation practices in place,
the Agency recommends that the permit writer use means other than historical flow for
setting the flow basis for the mass-based limitations. The MP&M Phase I flow guidance,
including discussions of flow trends and unit operation-specific production-normalized
flow rates, is a recommended tool for converting concentration-based limitations into
mass-based limitations. This flow guidance is discussed below.
The basis for the MP&M Phase I flow guidance is the production-normalized flow (PNF)
for each unit operation. The PNF represents the amount of wastewater discharged from
a unit operation per unit of production, as discussed in Section 5.0. Table 16-1 presents
descriptive statistics for PNFs obtained from the MP&M data collection portfolios
(DCPs). EPA mailed DCPs to over 1,000 MP&M Phase I sites. For most unit
operations, the PNFs are based on surface area as the production-normalizing
parameter. For six operations (abrasive jet machining, electrical discharge machining,
grinding, machining, plasma arc machining, and thermal cutting), the mass of metal
removed is the production-normalizing parameter.
Table 16-1 presents the following information for each of the MP&M unit operations:
• Total occurrences in DCP data (the presence of the unit operation
was reported, but flow and production data may not have been
available to calculate PNFs);
• Number of occurrences for which flow and production data were
available to calculate PNFs;
• Minimum PNF reported;
• Maximum PNF reported;
• Median PNF reported;
• Mean PNF reported;
• Upper and lower quartile PNF reported; and
• Tenth and ninetieth percentile PNF reported.
The sites that provided the raw data from which the statistics in Table 16-1 were derived,
have implemented pollution prevention and water conservation practices to varying
degrees. Some sites exhibited poor water use practices, while other sites effectively
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implemented one or more pollution prevention or water conservation practices. As a
result, the statistical data in Table 16-1 show a wide variation in production-normalized
flow. In some cases, the PNFs vary by several orders of magnitude or more. These
results are not surprising, given the drastic effects of pollution prevention and water
conservation practices on reducing flow. For example, implementing one practice such
as converting a single stage overflow rinse to a three stage countercurrent rinse can
reduce water use by a factor of 500 or more. Differences in manufactured parts or
processing requirements may also affect PNFs. Some of these production related
differences are discussed in Sections 16.2 through 16.5.
For sites that do not have pollution prevention and water conservation practices in place,
the permitting authority can use the PNFs in Table 16-1, in conjunction with the
appropriate production data for each unit operation at the site, to develop permit flow
rates for each unit operation. For example, the permitting authority could multiply the
quantity of production through each unit operation by an appropriate PNF for the
operation to calculate a permit flow for each operation. Then, the permit flows for each
operation could be summed to calculate a permit total flow for the site. The permit
total flow would be multiplied by the concentration limitations to calculate mass-based
limitations for the site.
When using a PNF for implementation, the permitting authority can select an
appropriate PNF from Table 16-1 for each unit operation on site. The Agency
recognizes that different part configurations and processing requirements may result in
differing water use requirements, even for multiple occurrences of the same operation at
a site. For example, a site manufacturing aerospace components may require a higher
PNF for rinsing after electroplating internal electronic components than for rinsing after
electroplating outer casings. Because of this diversity, while encouraging the use of
lower PNFs, the Agency has given the permit writer the flexibility to assess the water use
requirements for each site and use appropriate PNFs for the site.
While variations in water flow per unit of production result from variations in the part
configurations and processing requirements, on-site observations indicate that they are
more frequently the result of imprecise or inadequate control of water use. The
permitting authority should be aware of additional factors influencing PNF, and the
impact of these factors on the appropriate PNF for an operation at a site. Additional
guidance on the factors affecting PNFs and the determination of appropriate PNFs are
provided for the following major MP&M Phase I wastewater-generating unit operations
in Sections 16.2 through 16.5, respectively:
• Surface treatment rinsing operations (e.g., acid and alkaline
treatment rinsing, electroplating rinsing, anodizing rinsing, and
chemical conversion coating rinsing);
• Machining operations;
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• Painting operations; and
• Cleaning operations.
These operations generate approximately 75% of the wastewater generated by MP&M
Phase I sites. EPA estimates that 9,075 of the estimated 10,601 MP&M Phase I
wastewater-discharging sites perform one or more of these operations. For sites not
addressed by this flow guidance, EPA recommends that permit writers use best
professional judgment (BPJ) to develop mass-based limitations.
One approach for developing mass-based limitations is to use as a starting point the 25th
percentile PNF (i.e., the PNF value at which 25 percent of the sites were discharging less
water per unit of production) for the operations generating most of the process
wastewater on site. For sites that, due to process considerations, are unable to achieve
the 25th percentile PNF, the permit writer should use the median PNF as a starting
point.
16.2 Flow Guidance for Surface Treatment Rinsing Operations
This section provides flow guidance for surface treatment rinses, which are the primary
sources of MP&M Phase I process wastewater. Surface treatment rinses include those
following acid and alkaline treatment, anodizing, electroplating, electroless plating, and
chemical conversion coating. Rinsing is performed to dilute and remove the chemical
film of drag-out remaining on parts and racks after processing in a chemical bath. By
removing drag-out from the surface of the part, rinsing contributes to the quality of the
process and prevents the contamination of subsequent process baths. Available data
show that rinse water use rates are a function of production when measured in terms of
the surface area of parts processed and water use/conservation practices present at the
site.
Section 16.2.1 provides background information to identify pollution prevention and
water conservation practices applicable to surface treatment rinses, and evaluation
criteria to assess if a particular site has properly implemented these practices.
Section 16.2.2 presents guidance for selecting the appropriate flow rate for use in
calculating mass-based standards for sites that do not have pollution prevention and
water conservation practices in place. The guidance is based on DCP data and
information on various factors that impact rinse water requirements such as drag-out
rates and the required cleanliness or quality of rinse water.
16.2.1 Identifying Sites With Pollution Prevention and Water
Conservation Practices
As discussed in Section 16.1, the Agency recommends that permit writers use historical
flow data to calculate mass-based limitations for sites that have implemented pollution
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prevention and water conservation practices. This section provides background
information and guidance that can be used by the permit writer to determine if a site has
implemented pollution prevention and water conservation practices. If the site has
implemented pollution prevention and water conservation practices, the permit writer
could multiply the site's historical process wastewater discharge flow rate by the
concentration-based limitations to calculate mass-based limitations. This will eliminate
the requirement of identifying alternate methods to develop mass-based limitations,
including tracking production rates through unit operations.
Many MP&M Phase I sites employ some form of water conservation. A portion of sites
implement numerous water conservation methods and technologies in combination that
result in very low rinse water discharge rates and in some cases eliminate the discharge
of rinse water from individual processes. Water conservation is applicable to every
flowing rinse; however, process-related factors and site-specific conditions may restrict
the use of certain methods. This section identifies pollution prevention and water
conservation practices and technologies applicable to surface finishing rinses, presents
example configurations of these practices and technologies at MP&M sites, and provides
guidance on how to evaluate a site's water use practices.
Pollution Prevention and Water Conservation Practices and Technologies
The Agency has identified four categories of pollution prevention and water conservation
practices and technologies that can be applied to reduce rinse water use: drag-out
reduction and/or drag-out recovery methods; improved rinse tank design and innovative
rinsing configurations; rinse water use control devices; and, metal recovery and rinse
water reuse technologies. In addition to conserving water use, some of these methods
(especially those that affect drag-out and recover chemicals) also conserve raw materials
and reduce treatment reagent requirements and sludge production. Within each of these
categories are several specific practices and technologies. Table 16-2 presents several
examples of these practices and technologies, as well as their applicability to the MP&M
unit operations. Definitions of these practices are provided in Table 16-3.
Drag-Out Reduction and Drag-Out Recovery. The quantity of rinse water needed for
good rinsing for a given rinse system is proportional to the quantity of drag-out. Sites
can implement various methods that minimize the rate of drag-out (measured as gallons
per square foot of part surface area) and/or they can implement direct drag-out
recovery. The drag-out rate for an individual process operation (e.g., cleaning or plating)
is governed by numerous factors related mainly to the process type, shape of parts
processed, production equipment, and processing procedures, which include human
factors. Of these factors, the shape of the parts and the type of transport device
employed for the parts (e.g., racks, baskets, barrels) usually exhibit the greatest influence
on drag-out rates. The following tables present drag-out rate estimations for various
shaped parts.
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Estimations of Drag-Out Generation Presented in Literature
Average Drag-Out Losses - from Soderberg's Work
Nature of Work Drainage
Drag-Out Rate (gal/1,000 sq ft)
VERTICAL
Well Drained
Poorly Drained
Very Poorly Drained
0.4
2.0
4.0
HORIZONTAL
Well Drained
Very Poorly Drained
0.8
10.0
CUP SHAPES
Well Drained
Very Poorly Drained
8.0
24.0
Source: Reference 1.
Average Drag-Out Losses - from Hogaboom's Work
Electroplating Solution Type
Brass
Cadmium
Chromium (33 oz/gal)
Chromium (53 oz/gal) *
Copper cyanide
Watts nickel
Silver
Stannate tin
Acid zinc
Cyanide zinc
Drag-Out Rate (gal/1,000 sq ft)
Flat Surfaces
0.95
1.00
1.18
4.53
0.91
1.00
1.20
0.83
1.30
1.20
Contoured Surfaces
3.3
3.1
3.0
11.9
3.2
3.8
3.2
1.6
3.5
3.8
Source: Reference 1.
'Increased viscosity, caused by an increase in concentration, can increase the drag-out volume approximately three times with less than
double the concentration increase.
Soderberg's data indicate that the shape of the part has a significant influence on drag-
out rate. Cup shaped parts, including intricately designed parts with internal surfaces,
can generate five or more times more drag-out than flat surfaced parts with the same
surface area. Hogaboom's data show a similar trend for flat versus contoured surfaces.
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These data also show that the type and concentration of the electroplating solution
influences the drag-out rate. For example, some solutions, such as stannate tin, drain
effectively, while others, such as concentrated chromium electroplating solutions
(53 oz/gal) drain poorly. With regard to the type of transport device employed, barrels
(used to hold fasteners or other small parts that cannot be practically held by racks)
generate more drag-out than racks, because of the surface area of the barrel and its
tendency to hold the solution.
The drag-out rate for a given process and part is influenced by several factors other than
shape, some of which are interrelated. The following table shows the effect of altering
the withdraw rate and drain time.
Effect of Withdrawal Rate and Drain Time on Drag-out Rate
Micro-Etch Results
Baseline
Slower Rate of Withdrawal
Intermediate Withdrawal Rate
and Longer Drain Time
Withdrawal
Rate
(ft/mm)
100
11
40
Time of
Withdrawal
(seconds)
1.7
14.9
4.3
Drain
Time
(seconds)
3.4
2.5
12.1
Total
Time
(seconds)
5.1
17.4
16.4
Drag-out
(gal/1,000
sqft)
3.13
1.73
1.83
Eiectroless Copper Results
Baseline
Slower Rate of Withdrawal
Intermediate Withdrawal Rate
and Longer Drain Time
Withdrawal
Rate
(ft/min)
94
12
40
Time of
Withdrawal
(seconds)
1.8
13.9
4.3
Drain
Time
(seconds)
5.2
3.2
11.9
Total
Time
(seconds)
7.0
17
16.3
Drag-out
(gal/1,000
sqft)
1.55
0.78
0.75
Source: Reference 1.
*The effects of changing the withdrawal rate and drain time were measured at a printed circuit board
manufacturing site.
Table 16-4 lists these and other key factors and describes their impact on drag-out rates.
Also listed are examples of water conservation practices that reduce the generation of
drag-out, and the major restrictions that are associated with these practices. The
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following is a summary of additional methods that can be implemented to directly
recover drag-out.
1. Rinse over plating tank. Usually spray or fog rinse. Can only be
performed when evaporative headroom in plating tank is available.
2. Drip shield or board. An inclined board designed to capture drips
and return them to the plating tank as rack is being transported to
rinse.
3. Air knife. Device that directs an air stream at parts over the plating
tank or drip tank to blow off fluid.
4. Drip tank. An ordinary rinse tank that is initially empty over which
racks and barrels are held to drain. The collected drag-out is
returned to the plating bath.
5. Drag-out tank. A rinse tank that is initially filled with water but
remains stagnant. Parts are rinsed first in this tank. The diluted
drag-out can be returned to the process bath (e.g., electroplating
solution) if sufficient evaporative headroom exists in the process
tank.
6. Drag-in/Drag-out rinse. Two rinse tanks, located on opposite ends
of a process tank (e.g., electroplating tank) and hydraulically
connected, into which parts are rinsed before and after processing.
The drag-out from the first rinse becomes the drag-in to the process
tank, causing partial recovery of process solution. A useful
arrangement for ambient or low temperature processes where a
drag-out tank is not effective due to a low evaporation rate. On
manual lines a single rinse tank can perform the same function.
Parts are rinsed in the same tank, before and after processing.
Rinse Tank Design and Innovative Configurations. Rinse tank design and rinsing
configuration are important factors influencing the PNF for a rinse. The key objectives
with regard to optimal rinse tank design are to attain fast removal of drag-out from the
part and complete dispersion of the drag-out throughout the rinse tank. When these
objectives are achieved, the time necessary for rinsing is reduced and the concentration
of contaminants on the part when it leaves the rinse tank are minimized for a given rinse
water flow rate. Examples of good design elements include: locating water inlet and
discharge points of the tank at opposite positions in the tank to avoid short-circuiting;
and use of air agitation for better mixing (2).
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Various rinsing configurations are used in the MP&M Phase I industry. The use of
single rinse tanks following each process tank is the most inefficient use of rinse water.
Multiple rinse tanks connected in series (i.e., countercurrent cascade rinse) reduces the
water needs of a given rinsing operation by one or more orders of magnitude (i.e., less
water is needed to achieve the same rinsing criterion). Spray rinsing can also be used to
reduce water use requirements, but the achievable percent reduction is usually less than
for countercurrent cascade rinses. Other configurations that reduce water use include
cascade, reactive, and dual purpose rinses.
Rinse Water Use Control. Regardless of the type of rinsing configuration employed,
water use reduction can be achieved by coordinating water use and water use
requirements (i.e., rinse water is used in direct proportion to drag-out and the rinse
criterion is constantly achieved). When water use and water use requirements are
matched, the quantity of rinse water used for a given work load and tank arrangement is
optimized (2). Sites that have constantly running rinses and no regard for work flow are
the most inefficient users of water. A lack of water use control can negate the benefits
of using multiple rinse tanks or employing other water conservation practices and result
in a high PNF. Many sites employ some form of rinse water control. The four most
common methods are flow restrictors (these can be used in conjunction with other
methods to regulate the rate at which water is dispensed), manual control (i.e., turning
water valves on and off as needed), conductivity controls, and timer rinse controls (see
Table 16-3 for definitions).
Metal Recovery and Rinse Water Reuse Technologies. Various technologies are used by
MP&M sites to separate surface finishing chemicals from rinse waters or to concentrate
the rinse waters, thereby making the chemical and/or rinse water available for reuse.
These technologies result in metal recovery and water conservation. The most
commonly used technologies are evaporation, ion exchange, electrolytic recovery, reverse
osmosis, and electrodialysis (see Table 16-3 for definitions). The following table presents
examples of recovery technologies and their primary applications.
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Examples of Metal Recovery Methods
Chemistry or Process
with which Rinse is Associated
Brass Electroplating
Cadmium (cyanide) Electroplating
Cadmium (non-cyanide) Electroplating
Chromate Conversion Coating of aluminum
Chromium (hard) Anodizing
Chromium Electroplating - decorative (Cr*6)
Chromium Electroplating - decorative (Cr+3)
Copper (cyanide and sulfate) Electroplating
Gold Electroplating
Lead-tin Electroplating
Nickel Electroplating
Nickel Electroless Plating
Nickel Sealant
Silver Electroplating
Zinc (cyanide) Electroplating
Zinc (non-cyanide) Electroplating
Zincate
Recovery Method Examples
Electrolytic recovery, evaporation
Electrodialysis, electrolytic recovery, evaporation, ion exchange, reverse osmosis
Electrodialysis, electrolytic recovery, evaporation, ion exchange, reverse osmosis
Evaporation
Evaporation, mist eliminator
Evaporation
Evaporation
Electrolytic recovery, evaporation, ion exchange, reverse osmosis
Electrolytic recovery, ion exchange
Evaporation, ion exchange
Electrodialysis, electrolytic recovery, evaporation, ion exchange, reverse osmosis
Evaporation, ion exchange
Reverse osmosis
Electrolytic recovery, evaporation, ion exchange
Electrolytic recovery, evaporation, reverse osmosis
Electrolytic recovery, evaporation, ion exchange, reverse osmosis
Evaporation
Source: Reference 2.
Summary of Water Conservation Methods
Figure 16-2 presents six examples of rinsing configurations with increasingly good levels
of water use practices. Each of these rinse systems is described below. These
configurations can be operated to provide adequate rinsing and are common at MP&M
Phase I sites. However, the quantity of water needed to achieve the same rinsing criteria
may vary by as much as two orders of magnitude. The MP&M Phase I effluent
limitations guidelines and standards are based on the following rinsing configuration:
flow control and countercurrent cascade rinses for all flowing rinses, and ion exchange
with electrolytic recovery for all electroplating rinses except chromium electroplating
rinses.
Figure 16-2a presents an example of inefficient water use. This configuration involves
the employment of a single rinse tank with either continuous water flow or manual use
control. To coordinate rinse water needs and use, the water valve must be manually
turned on to give the correct flow rate and then turned off when the flow is no longer
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needed. The flow rate setting will usually vary from operator to operator and the water
valve may be left open during idle production periods. The single rinse tank
configuration results in a very high rinse water use rate, even if water use is coordinated
with the introduction of drag-out. In the example shown, with a 1 gallon per hour (gph)
drag-out rate, the rinse water requirement would be 30 gallons per minute, based on
rinsing of Watts nickel plating solution and a rinsing criterion of 50 mg/L nickel.
Rinsing criteria are discussed in Section 16.2.2. If coordination of water use and drag-
out introduction are not achieved, an even higher rinse water use rate would be needed
to meet a given rinse criterion.
Figure 16-2b shows a rinsing configuration where simple rinse water reduction methods
have been implemented. The use of water is still inefficient due to the use of a single
rinse tank versus the use of multiple rinse tanks shown in subsequent configurations.
However, with this configuration, the drag-out rate is reduced by controlling the
withdrawal rate of the part and by holding the part over the process tank to permit the
drag-out to drip into the tank. The rinse water flow rate is controlled at a constant flow
by use of a flow restrictor. The flow restrictor is usually sized to provide adequate
rinsing at all times. This type of control is more acceptable for constant production
rates, such as that often found with automated plating machines. However, this rinsing
configuration is inefficient when there is an intermittent work flow because the rinse
water flow rate must be set high enough to provide adequate rinsing during peak
production periods. During low or idle production periods a large quantity of rinse
water is wasted, unless the water flow is manually stopped.
Figure 16-2c shows a rinsing configuration with a moderately efficient use of water. This
is achieved by the employment of a multiple rinse tank arrangement. The arrangement
is referred to as parallel rinsing, where each of the two rinse tanks are fed with fresh
water and they each discharge to treatment. This arrangement can reduce water use by
more than 50% of that used in Figure 16-2a.
Figure 16-2d shows a more efficient rinsing configuration. This configuration is similar
to that shown in Figure 16-2c, except that wastewater from the second rinse tank flows
back into the first rinse tank to provide more efficient rinsing with less water use.
Wastewater from the first rinse tank is then discharged to treatment. In this
configuration, known as countercurrent cascade rinsing, the rinse water flows in a
direction opposite the part flow. This arrangement can reduce water use by more than
90% of that used in Figure 16-2a.
Figure 16-2e shows a very efficient rinsing configuration. There are three key elements
to this rinse system: drag-out reduction/recovery; countercurrent cascade rinses; and
water use control. Drag-out reduction/recovery is achieved by controlling the withdrawal
rate and dwell time and by installing a drag-out recovery tank. The drag-out recovery
tank can reduce the drag-out entering the countercur |