SER&
  United States
  Environmental Protection
  Agency
  Development Document For the
  Final Effluent Limitations
  Guidelines and Standards for the
  Metal Products and Machinery
  Point Source Category
         Printed on paper containing at least 30% postconsumer recovered fiber.

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U.S. Environmental Protection Agency
       Office of Water (4303T)
   1200 Pennsylvania Avenue, NW
       Washington, DC 20460
         EPA-821-B-03-001

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 Development Document For The
    Final Effluent Limitations
    Guidelines and Standards
             For The
  Metal Products & Machinery
      Point Source Category

        EPA-821-B-03-001
       Christine Todd Whitman
            Administrator

         G. Tracy Mehan, m
 Assistant Administrator, Office of Water

         Geoffrey H. Grubbs
Director, Office of Science and Technology

           Sheila E. Frace
Director, Engineering and Analysis Division

            Marvin Rubin
         Chief, Energy Branch

           Shari Z. Barash
         Technical Coordinator

           Jan S. Matuszko
         Technical Coordinator

        Carey A. Johnston, P.E.
           Project Manager
           February 2003

  U.S. Environmental Protection Agency

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                                   Office of Water
                               Washington, DC 20460
ACKNOWLEDGMENTS AND DISCLAIMER
       The Agency would like to acknowledge the contributions  of Shari Barash, Yu-Ting
Guilaran, Carey Johnston, Jan Matuszko, Marvin Rubin, Maria Smith, and Richard Witt to
development of this technical document.  In addition, EPA acknowledges the contribution of
Eastern Research Group, Westat, Abt Associates,  and Science Applications International
Corporation.

       Neither the United  States  government nor  any  of its employees,  contractors,
subcontractors, or other employees makes any warranty, expressed or implied, or assumes any
legal liability or responsibility for any third party's use of,  or the results of such use of, any
information, apparatus, product, or process discussed in this report, or represents that its use by
such a third party would not infringe on privately owned rights.  References  to  proprietary
technologies are not intended to be an endorsement by the Agency.

Questions or comments regarding this technical document should be addressed to:

Mr. Carey A. Johnston, P.E.
Environmental Engineer
Engineering and Analysis Division  (4303T)
U.S. Environmental Protection Agency
1200 Pennsylvania Avenue, N.W.
Washington, DC 20460
(202)566- 1014
j ohnston.carey@epa.gov

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                                                                            Table of Contents

                                TABLE OF CONTENTS

                                                                                  Page

1.0           SUMMARY AND SCOPE OF THE REGULATION	1-1
              1.1    Overview of the MP&M Point Source Category	1-1
              1.2    Overlap with Other Effluent Guidelines  	1-5
              1.3    Summary of Applicability  	1-7
              1.4    Promulgated Effluent Limitations Guidelines and Standards  	1-8
              1.5    Protection of Confidential Business Information	1-9

2.0           BACKGROUND  	2-1
              2.1    Legal Authority  	2-1
              2.2    Regulatory Background	2-1
                    2.2.1   Clean Water Act	2-1
                    2.2.2   Section 304(m) Requirements	2-5
                    2.2.3   Pollution Prevention Act	2-5
                    2.2.4   Regulatory Flexibility Act (RFA) as Amended by the
                           Small Business Regulatory Enforcement Fairness Act of 1996
                           (SBREFA) 	2-6
                    2.2.5   Regulatory History of the Metals Industry	2-8

3.0           DATA COLLECTION ACTIVITIES	3-1
              3.1    Industry Questionnaires	3-1
                    3.1.1   The 1989 Industry Surveys 	3-2
                           3.1.1.1  1989 Screener Survey  	3-2
                           3.1.1.2  1989 Detailed Survey	3-8
                    3.1.2   The 1996 Industry Surveys 	3-12
                           3.1.2.1  1996 Screener Survey  	3-13
                           3.1.2.2  1996 Long Detailed Survey	3-16
                           3.1.2.3  1996 Short Detailed Survey	3-19
                           3.1.2.4  1996 Municipality Detailed Survey	3-21
                           3.1.2.5  1996 Federal Facilities Detailed Survey  	3-23
                           3.1.2.6  1996 POTW Detailed  Survey   	3-25
                    3.1.3   1997 Iron and Steel Industry Survey Data	3-26
                    3.1.4   Data Submitted by the American Association of Railroads
                           (AAR)   	3-32
                    3.1.5   National Estimates	3-33
              3.2    Site Visits	3-34
                    3.2.1   Criteria for Site Selection	3-35
                    3.2.2   Information Collected  	3-38
              3.3    EPA MP&M Sampling Program	3-38
                    3.3.1   Criteria for Site Selection	3-39
                    3.3.2   Information Collected  	3-40

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                    3.3.3   Sample Collection and Analysis  	3-41
             3.4    Other Sampling Data	3-46
             3.5    Other Industry-Supplied Data  	3-48
             3.6    Other Data Sources  	3-49
                    3.6.1   EPA/EAD Databases	3-50
                    3.6.2   Fate of Priority Pollutants in Publicly Owned Treatment
                           Works Database	3-50
                    3.6.3   National Risk Management Research Laboratory (NRMRL)
                           Treatability Database	3-51
                    3.6.4   The Domestic Sewage Study	3-51
                    3.6.5   Toxics Release Inventory (TRI) Database	3-52
                    3.6.6   Discharge Monitoring Reports from EPA's Permit
                           Compliance System	3-52
             3.7    References 	3-53

4.0          INDUSTRY DESCRIPTION	4-1
             4.1    Overview of MP&M facilities	4-1
                    4.1.1   Number and  Size of MP&M Facilities  	4-2
                    4.1.2   Geographic Distribution	4-3
                    4.1.3   Wastewater-Discharging Facilities  	4-4
                    4.1.4   Non-Wastewater-Discharging Facilities 	4-9
             4.2    Proposed MP&M Operations	4-11
                    4.2.1   Types of Unit Operations	4-12
                    4.2.2   Description of Proposed MP&M Operations  	4-14
                           4.2.2.1 Description of MP&M Oily Operations	4-17
                           4.2.2.2 Description of MP&M Metal-bearing Operations .... 4-22
                    4.2.3   Metals Processed	4-34
                    4.2.4   Estimated Annual Wastewater Discharge 	4-34
             4.3    Trends in the Industry  	4-41
             4.4    References 	4-41

5.0          WASTEWATER CHARACTERISTICS 	5-1
             5.1    Process Water and Rinse Water  	5-1
             5.2    Influent to Oily Wastewater Treatment Systems	5-13

6.0          INDUSTRY SUBCATEGORIZATION	6-1
             6.1    Methodology and Factors  Considered for Basis of Subcategorization . 6-1
                    6.1.1   Factors Contributing to the Subcategorization Structure
                           Evaluated for the Final Rule 	6-2
                    6.1.2   Factors That  are Not a Basis For MP&M Subcategorization  . 6-13
                                           11

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             6.2    General Description of Facilities in Each Subcategory Evaluated
                    for the Final Rule	6-17
                    6.2.1   General Metals Subcategory Evaluated for the Final Rule  ... 6-17
                    6.2.2   Metal Finishing Job Shops  Subcategory Evaluated for the
                           Final Rule	6-19
                    6.2.3   Non-Chromium Anodizing Subcategory Evaluated for the
                           Final Rule	6-19
                    6.2.4   Printed Wiring Board Subcategory Evaluated for the Final
                           Rule  	6-20
                    6.2.5   Steel Forming and Finishing Subcategory Evaluated for the
                           Final Rule	6-20
                    6.2.6   Oily Wastes  Subcategory	6-20
                    6.2.7   Railroad Line Maintenance Subcategory Evaluated for the
                           Final Rule	6-22
                    6.2.8   Shipbuilding Dry Dock Subcategory	6-23

7.0          SELECTION OF POLLUTANT PARAMETERS  	7-1
             7.1    Identification of Pollutants of Concern 	7-1
             7.2    Regulated Pollutants  	7-12
             7.3    References 	7-14

8.0          POLLUTION PREVENTION PRACTICES AND WASTEWATER
             TREATMENT TECHNOLOGIES  	8-1
             8.1    Flow Reduction Practices  	8-1
                    8.1.1   Rinse Tank Design and Innovative Configurations	8-2
                    8.1.2   Additional Design Elements  	8-7
                    8.1.3   Rinse Water  Use Control	8-8
                    8.1.4   Pollution Prevention for Process Baths	8-9
             8.2    In-Process Pollution Prevention Technologies  	8-9
                    8.2.1   Activated Carbon Adsorption  	8-12
                    8.2.2   Carbonate "Freezing"	8-13
                    8.2.3   Centrifugation  and Pasteurization of Machining Coolants  ...8-13
                    8.2.4   Centrifugati on  and Recycling of Painting Water Curtains  ... 8-14
                    8.2.5   Electrodialysis 	8-16
                    8.2.6   Electrolytic Recovery	8-17
                    8.2.7   Evaporation  	8-19
                    8.2.8   Filtration	8-20
                           8.2.8.1 Ion Exchange (in-process)	8-21
                           8.2.8.2 Reverse Osmosis 	8-24
             8.3    Best Management Practices and Environmental Management
                    Systems for Pollution Prevention	8-25
                                           in

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           TABLE OF CONTENTS (Continued)

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      8.3.1  Pollution Prevention for Cleaning and Degreasing
            Operations  	8-27
      8.3.2  Pollution Prevention for Machining Operations  	8-28
      8.3.3  Painting Operations	8-29
      8.3.4  Pollution Prevention for Printed Wiring Board
            Manufacturing 	8-29
.4     Preliminary Treatment of Segregated Wastewater Streams	8-30
      8.4.1  Chromium-Bearing Wastewater 	8-31
      8.4.2  Concentrated Metal-Bearing Wastewater 	8-36
      8.4.3  Cyanide-Bearing Wastewater	8-36
            8.4.3.1 Alkaline Chlorination	8-37
            8.4.3.2 Ozone Oxidation 	8-38
      8.4.4  Chelated-Metal-Bearing Wastewater	8-39
            8.4.4.1 Reduction to Elemental Metal	8-39
            8.4.4.2 Precipitation as an Insoluble Compound	8-40
            8.4.4.3 Physical Separation  	8-41
      8.4.5  Oil-Bearing Wastewater	8-41
            8.4.5.1 Chemical Emulsion Breaking  	8-42
            8.4.5.2 Oil Skimming	8-44
            8.4.5.3 Flotation of Oils or Solids  	8-46
            8.4.5.4 Ultrafiltration	8-47
.5     End-of-Pipe Wastewater Treatment and Sludge-Handling
      Technologies 	8-48
      8.5.1  Chemical Precipitation for Metals Removal  	8-48
            8.5.1.1 Gravity Clarification for Solids Removal  	8-54
            8.5.1.2 Microfiltration for Solids Removal 	8-55
            8.5.1.3 Optimization of Existing Chemical Precipitation
                   Treatment System 	8-56
      8.5.2  Oil Removal	8-57
      8.5.3  Polishing Technologies  	8-58
            8.5.3.1 Multimedia Filtration	8-58
            8.5.3.2 Activated Carbon Adsorption  	8-59
            8.5.3.3 Reverse Osmosis 	8-59
            8.5.3.4 Ion Exchange	8-59
      8.5.4  Sludge Handling	8-60
            8.5.4.1 Gravity Thickening  	8-60
            8.5.4.2 Pressure Filtration 	8-61
            8.5.4.3 Vacuum Filtration 	8-62
            8.5.4.4 Sludge Drying  	8-63
.6     References 	8-63
                             IV

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                         TABLE OF CONTENTS (Continued)

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9.0          TECHNOLOGY OPTIONS  	9-1
             9.1    Technology Evaluation Methods	9-1
             9.2    General Metals Subcategory 	9-2
                   9.2.1   Best Practicable Control Technology Currently Available
                          (BPT)	9-2
                   9.2.2   Best Conventional Pollutant Control Technology (BCT) 	9-8
                   9.2.3   Best Available Technology Economically Achievable (BAT)  . 9-9
                   9.2.4   New Source Performance Standards (NSPS)	9-10
                   9.2.5   Pretreatment Standards for Existing Sources (PSES) 	9-11
                   9.2.6   Pretreatment Standards for New Sources (PSNS)	9-13
             9.3    Metal Finishing Job Shops Subcategory  	9-14
                   9.3.1   BPT, BCT, and BAT 	9-14
                   9.3.2   NSPS 	9-15
                   9.3.3   PSES  	9-16
                   9.3.4   PSNS 	9-17
             9.4    Non-Chromium Anodizing  Subcategory	9-18
                   9.4.1   BPT, BCT, and BAT 	9-18
                   9.4.2   NSPS 	9-19
                   9.4.3   PSES and PSNS	9-19
             9.5    Printed Wiring Board Subcategory  	9-20
                   9.5.1   BPT, BCT, and BAT 	9-20
                   9.5.2   NSPS 	9-20
                   9.5.3   PSES  	9-21
                   9.5.4   PSNS 	9-22
             9.6    Steel Forming and Finishing Subcategory	9-23
                   9.6.1   BPT, BCT, and BAT 	9-23
                   9.6.2   NSPS 	9-24
                   9.6.3   PSES  	9-24
                   9.6.4   PSNS 	9-24
             9.7    Oily Wastes Subcategory	9-25
                   9.7.1   BPT  	9-25
                   9.7.2   BCT  	9-28
                   9.7.3   BAT	9-28
                   9.7.4   NSPS 	9-28
                   9.7.5   PSES  	9-29
                   9.7.6   PSNS 	9-30
             9.8    Railroad Line Maintenance  Subcategory	9-31
                   9.8.1   BPT  	9-31
                   9.8.2   BCT  	9-33
                   9.8.3   BAT	9-34

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                   9.8.4   NSPS 	9-34
                   9.8.5   PSES and PSNS	9-34
             9.9    Shipbuilding Dry Dock Subcategory	9-35
                   9.9.1   BPT 	9-35
                   9.9.2   PSES and PSNS	9-36
             9.10   Summary of Technology Options Considered and Selected for the
                   Final MP&M Rule	9-36

10.0          LIMITATIONS AND STANDARDS: DAT A SELECTION AND CALCULATION  .... 10-1
             10.1   Overview of Data Selection	10-1
             10.2   Episode and Data Selection	10-2
             10.3   Data Aggregation	10-9
                   10.3.1 Aggregation of Field Duplicates 	10-11
                   10.3.2 Aggregation of Grab Samples 	10-11
             10.4   Overview of Limitations 	10-12
                   10.4.1 Objective 	10-12
                   10.4.2 Selection of Percentiles  	10-13
                   10.4.3 Compliance with Limitations	10-14
             10.5   Calculation of the Limitations	10-15
             10.6   Evaluation of the Limitations	10-16
                   10.6.1 Comparison to Data	10-17
                   10.6.2 Comparison to Proposed and NOD A Values	10-21

11.0          COSTS OF TECHNOLOGY BASES FOR REGULATIONS	11-1
             11.1   Summary of Costs  	11-1
             11.2   Development of Cost Model Inputs	11-6
                   11.2.1   Model Site Development  	11-6
                   11.2.2   Wastewater Streams and Flow Rates  	11-7
                   11.2.3   Wastewater Pollutant Concentrations	11-9
                   11.2.4   Technology in Place 	11-10
                            11.2.4.1    Baseline Model Runs	11-15
                            11.2.4.2    Post-Compliance Model  Runs	11-16
                            11.2.4.3    New Source Model Runs	11-16
             11.3   General Methodology for Estimating Costs of Treatment
                   Technologies 	11-17
                   11.3.1   Components of Cost	11-18
                            11.3.1.1    Total Annualized Costs  	11-19
                   11.3.2   Sources and Standardization of Cost Data	11-20
                   11.3.3   Development of the Cost Model	11-25
                            11.3.3.1    Modeling Technology Options  	11-26
                            11.3.3.2    Modeling Flow Reduction	11-30
                                         VI

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               11.3.3.3     Modeling End-of-Pipe Treatment for Metal
                           Bearing Subcategories	11-30
               11.3.3.4     Modeling End-of-Pipe Treatment for Oily
                           Subcategories	11-31
               11.3.3.5     Model Output	11-31
       11.3.4   General Assumptions Made During the Costing Effort  ...  11-31
11.4   Specific Methodology and Assumptions Used to Estimate Costs for
       Treatment Technologies	11-34
       11.4.1   NODA Cost Estimates  	11-35
       11.4.2   Post-NODA Cost Estimates 	11-37
11.5   Costing Methodologies for Direct Discharging Oil-Bearing
       Subcategories	11-39
       11.5.1   Oily Wastes Costing Methodology	11-39
       11.5.2   Railroad Line Maintenance Costing Methodology	11-40
       11.5.3   Shipbuilding Dry Dock Costing Methodology	11-40
11.6   Design and Costs of Individual Pollution Control Technologies  . . .  11-40
       11.6.1   Countercurrent Cascade Rinsing	11-41
       11.6.2   Centrifugation and Pasteurization of Machining Coolant  .  11-41
       11.6.3   Centrifugation of Painting Water Curtains  	11-42
       11.6.4   Contracting for Off-Site Treatment and Disposal	11-49
       11.6.5   Feed Systems and Chemical Dosages	11-49
       11.6.6   Chemical Emulsion Breaking and Gravity Oil/Water
               Separation	11-52
       11.6.7   Dissolved Air Flotation	11-53
       11.6.8   Ultrafiltration System for Oil Removal  	11-54
       11.6.9   Batch Oil Emulsion Breaking with Gravity Flotation	11-54
       11.6.10  Chemical Reduction of Hexavalent Chromium 	11-55
       11.6.11  Cyanide Destruction	11-56
       11.6.12  Chemical Reduction/Precipitation of Chelated Metals  ...  11-57
       11.6.13  Chemical Precipitation  	11-57
       11.6.14  Sedimentation by Slant-Plate Clarifier	11-58
       11.6.15  Multimedia Filtration  	11-59
       11.6.16  Microfiltration for Solids Removal	11-59
       11.6.17  Sludge Thickening  	11-60
       11.6.18  Sludge Pressure Filtration	11-60
11.7   References  	11-61
                             vn

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12.0         POLLUTANT LOADING AND REDUCTION ESTIMATES	12-1
             12.1   Estimation of Unit Operation Wastewater Pollutant Concentrations  .  12-2
                    12.1.1   Unit Operation Wastewater Data Collection  	12-2
                    12.1.2   Calculation of Pollutant Concentrations for Each Unit
                            Operation for Each Sampling Point from EPA or Industry-
                            Supplied Sampling Data	12-3
                    12.1.3   Estimation of Pollutant Concentrations for Each
                            Subcategory and Unit Operation	12-4
                            12.1.3.1     Identification of Unit Operations Reported in
                                        the Detailed Surveys  	12-4
                            12.1.3.2     Estimation of Wastewater Pollutant
                                        Concentrations for Each Unit Operation/
                                        Subcategory Combination  	12-5
                            12.1.3.3     Estimation of Applied Metal Concentrations
                                        Using Available Analytical Data	12-7
                            12.1.3.4     Modeling of Pollutant Concentrations for
                                        Each Model Site Unit Operation 	12-8
             12.2   Estimation of Industry Baseline Pollutant Loadings 	12-9
                    12.2.1   Estimation of Baseline Pollutant Concentrations from
                            Sites in the Metal-Bearing Subcategories	12-10
                            12.2.1.1     Estimation of Effluent Pollutant
                                        Concentrations for Untreated Streams	12-10
                            12.2.1.2     Estimation of Effluent Pollutant
                                        Concentrations for Treated Streams	12-11
                            12.2.1.3     Estimation of Commingled Effluent Pollutant
                                        Concentrations from Sites  	12-14
                    12.2.2   Estimation of Baseline Pollutant Concentrations from
                            Sites in the Oil-Bearing Subcategories	12-15
                            12.2.2.1     Estimation of Baseline Pollutant
                                        Concentrations from Sites in the Shipbuilding
                                        Dry Dock Subcategory	12-15
                            12.2.2.2     Estimation of Baseline Pollutant
                                        Concentrations from Sites in the Railroad
                                        Line Maintenance Subcategory  	12-16
                            12.2.2.3     Estimation of Baseline Pollutant
                                        Concentrations from Sites in the Oily Wastes
                                        Subcategory	12-16
                    12.2.3   Estimation of Model Site Baseline Loadings	12-17
                    12.2.4   Estimation of Industry-Wide Baseline Pollutant Loadings . 12-17
                                          Vlll

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             12.3   Estimation of Industry Option Pollutant Loadings  	12-18
                    12.3.1   Estimation of Industry Option Pollutant Loadings for Sites
                            in the Metal-Bearing Subcategories	12-18
                    12.3.2   Estimation of Industry Option Pollutant Loadings for Sites
                            in the Shipbuilding Dry Dock Subcategory  	12-19
                    12.3.3   Estimation of Industry Option Pollutant Loadings for Sites
                            in the Railroad Line Maintenance Subcategory 	12-19
                    12.3.4   Estimation of Industry Option Pollutant Loadings for Sites
                            in the Oily Wastes Subcategory 	12-19
             12.4   Estimation of Pollutant Reductions	12-20

13.0         NON-WATER QUALITY IMP ACTS  	13-1
             13.1   Energy Requirements	13-1
             13.2   Air Emissions Impacts	13-2
             13.3   Solid Waste Generation	13-3
             13.4   References  	13-4

14.0         LONG-TERM AVERAGES AND EFFLUENT LIMITATIONS AND STANDARDS  ....  14-1
             14.1   General Metals Subcategory 	14-1
             14.2   Metal Finishing Job Shops Subcategory  	14-2
             14.3   Non-Chromium Anodizing Subcategory	14-2
             14.4   Printed Wiring Board Subcategory  	14-2
             14.5   Steel Forming and Finishing Subcategory	14-2
             14.6   Oily Wastes Subcategory	14-2
                    14.6.1   Best Practicable Control Technology (BPT)	14-2
                    14.6.2   Best Conventional Pollutant Control Technology (BCT) . . .  14-4
                    14.6.3   Best Available Technology Economically Achievable
                            (BAT)  	14-4
                    14.6.4   New Source Performance Standards (NSPS)	14-4
                    14.6.5   Pretreatment Standards for Existing Sources (PSES)	14-4
                    14.6.6   Pretreatment Standards for New Sources (PSNS)  	14-4
             14.7   Railroad Line Maintenance Subcategory	14-5
             14.8   Shipbuilding Dry Dock Subcategory	14-5

15.0         IMPLEMENTATION	15-1
             15.1   Applicability of the MP&M Effluent Guidelines 	15-1
                    15.1.1   MP&M Industrial Sectors	15-2
                    15.1.2   Regulated Subcategory in the MP&M Effluent Guidelines .15-3
                    15.1.3   Facilities Not Subject to the MP&M Effluent Guidelines  . .  15-3
             15.2   Compliance Dates 	15-9
             15.3   Limits Development	15-9
                                          IX

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           15.4  Compliance Monitoring	15-12
           15.5  References 	15-13

16.0        GLOSSARY OF TERMS	16-1

Appendix A  -     EXAMPLE NAICS AND SIC CODES FOR THE METAL PRODUCTS
                & MACHINERY FINAL EFFLUENT LIMITATIONS GUIDELINES
                AND STANDARDS

Appendix B  -     ANALYTICAL METHODS AND BASELINE VALUES FOR THE
                METAL PRODUCTS AND MACHINERY INDUSTRY

Appendix C  -     WASTEWATER CHARACTERISTICS

Appendix D  -     POLLUTION PREVENTION AND WATER CONSERVATION
                PRACTICES

Appendix E  -     MODIFIED DELTA-LOGNORMAL DISTRIBUTION

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                                                                             List of Tables

                                  LIST OF TABLES

                                                                                 Page

1-1          Clarification of Coverage by Proposed MP&M Subcategory	1-6

1-2          Technology Bases for Promulgated MP&M Limitations and Standards	1-9

1-3          Effluent Limitations Guidelines for the MP&M Point Source Category
             (40 CFR 438)	1-9

2-1          Summary of Regulatory Levels of Control 	2-4

2-2          Summary of Metals Industry Effluent Guidelines	2-9

3-1          1989 and 1996 MP&M Survey Mailout Results	3-5

3-2          Summary of 1996 Detailed Survey Information by Question Number	3-18

3-3          Number of Sites Visited Within Each Proposed Industrial Sector  	3-35

3-4          Number of Sites Sampled Within Each Proposed Industrial	3-39

3-5          Metal Constituents Measured Under the MP&M Sampling Program	3-42

3-6          Organic Constituents Measured Under the MP&M Sampling Program	3-43

3-7          Additional Parameters Measured Under the MP&M Sampling Program ....  3-47

4-1          Wastewater-Discharging MP&M facilities by Sector	4-5

4-2          Types of Proposed MP&M operations  	4-13

4-3          List of MP&M Oily Operations	4-15

4-4          List of MP&M Metal-Bearing Operations	4-16

4-5          Estimated Number of MP&M Facilities Discharging Process Wastewater
             by Proposed MP&M Operation and Estimated Annual Discharge
             for Each Proposed MP&M Operation	4-36

5-1          Number of Process Water and Rinse Water Samples For Oily Operations .... 5-2

5-2          Process Water Pollutant Concentration Data for Oily Operations	5-3


                                         xi

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5-3          Rinse Water Pollutant Concentration Data for Oily Operations 	5-8

5-4          MP&M Pollutant Concentration Data for the Influent to Oily Wastewater
             Treatment Systems	5-14

6-1          Final Subcategories Evaluated in the Final Rule	6-2

6-2          Oily Operations as Defined by the Final Rule	6-3

6-3          Metal-Bearing Operations as Defined by the Final Rule	6-4

6-4          Percentage of Facilities Performing Proposed MP&M Operations
             Using Multiple Metal Types by Subcategory	6-6

6-5          Percentage of Facilities Performing Proposed MP&M Operations
             by Subcategory Using Each Metal Type  	6-8

7-1          Pollutants Not Detected in Any Samples Collected During the
             Phase I and Phase n MP&M Sampling Programs	7-4

7-2          Pollutants Detected in Less Than Three Samples Collected
             During the Phase I and Phase n MP&M Sampling Programs	7-6

7-3          Pollutants Detected at Average Concentrations of Less Than Five
             Times the Minimum Level During the Phase I and Phase n MP&M
             Sampling Programs  	7-7

7-4          Summary of Pollutants of Concern Information 	7-8

7-5          Pollutants Considered for Regulation for Direct Dischargers in the
             Oily Wastes Subcategory	7-15

             MP&M Flow Reduction Technologies   	8-3

             MP&M In-Process Pollution Prevention Technologies	8-10

8-3          MP&M Preliminary and End-of-Pipe Treatment Technologies 	8-32

9-1          Technology Options by Subcategory	9-37

9-2          Summary of Technology Bases for the Final Rule 	9-38
                                          xn

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                                                                              List of Tables
                            LIST OF TABLES (Continued)

                                                                                  Page

10-1         Oily Wastes Subcategory Oil/Water Separation 	10-3

10-2         Unit Operations at Each Episode	10-5

10-3         Effluent Data Before Aggregation	10-10

10-4         Data After Aggregation (i.e., Daily Values)  	10-11

10-5         Episode Long-Term Averages and Daily Variability Factors 	10-15

10-6         Option Long-Term Averages, Daily Variability Factors, and Limitations .  . 10-17

10-7         Daily Maximum Limitations: Proposal, NOD A, and Final Rule  	10-22

11-1         Incremental Capital and O&M Costs	11-2

11-2         Incremental Annualized Costs	11-4

11-3         Information Contained in MSP1  	11-8

11-4         Information Contained in MSP2  	11-10

11-5         Treatment Technologies Considered Equivalent to the Option
             Technologies 	11-13

11-6         Information Contained in MSP3  	11-15

11-7         Components of Total Capital Investment  	11-19

11-8         Costs for Contracted Off-Site Treatment/Disposal of Various Waste Types  11-21

11-9         RS Means Building Construction Historical Cost Indexes 	11-22

11-10        Monitoring Frequencies Used to Develop Part 438 Limitations Considered
             for Metal-Bearing Subcategories  	11-23

11-11        Wastewater Treatment Technologies and Source Reduction and Recycling
             Practices for Which EPA Developed Cost Modules	11-26

11-12        List of Unit Operations Feeding Each Treatment Unit or In-Process
             Technology  	11-27

                                         xiii

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                                                                             List of Tables
                            LIST OF TABLES (Continued)

                                                                                Page

11-13        MP&M Equipment Cost Equations	11-43

11-14        Logic Used for Off-Site Treatment and Disposal Cost Estimates	11-50

11-15        Treatment Technologies That Use Feed Systems  	11-51

11-16        Treatment Dosage Information 	11-52

12-1          POTW Removal Percentages For Each MP&M Pollutant of Concern  	12-22

12-2          Summary of Baseline Annual Pollutant Loadings Discharged by
             Subcategory	12-26

12-3          Summary of Selected Option Annual Pollutant Loadings Discharged by
             Subcategory	12-28

12-4          Industry Pollutant Removals in Pounds (for Direct Dischargers)  	12-30

12-5          Industry Pollutant Removals in Pound-Equivalents  	12-31

13-1          Energy Usage for the Selected Technology Option	13-1

13-2          Waste Oil Removed by the Selected Option	13-3

14-1          BPT Effluent Limitations for the Oily Wastes Subcategory 	14-3

15-1          Clarification of Coverage by MP&M Subcategory Evaluated for
             the Final Rule	15-5

15-2          Effluent Limitations Guidelines for the MP&M Point Source Category
             (40CFR438)	15-11

16-1          Priority and Nonconventional Organic Pollutants Comprising the Total
             Organics Parameter	16-12
                                         xiv

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                                                                              List of Figures

                                  LIST OF FIGURES

                                                                                  Page

3-1          Percentage of 1989 and 1996 MP&M Surveys Returned and Percentage of
             Survey Respondents Performing Proposed MP&M Operations  	3-6

3-2          Number of Facilities Performing Proposed MP&M Operations Visited and
             Sampled by Industrial  Sector	3-36

4-1          Percentage of Wastewater-Discharging MP&M facilities and Percentage of
             Annual Wastewater Discharge by Number of Employees	4-3

4-2          Estimated Number of Wastewater-Discharging MP&M facilities
             by EPA Region	4-4

4-3          Percentage of Wastewater-Discharging MP&M facilities and Percentage of
             Total Annual Discharge by Activity 	4-7

4-4          Percentage of Wastewater-Discharging MP&M facilities and Percentage of
             Total Annual Discharge by Discharge Status  	4-8

4-5          Percentage of Wastewater-Discharging MP&M facilities and Percentage of
             Total Annual MP&M Discharge by Flow Rate Range  	4-9

4-6          Percentage of Screener Survey Respondents Using Each Zero Discharge
             Method	4-11

4-7          Percentage of Wastewater-Discharging MP&M facilities by Number of
             Metal Processed	4-35

6-1          Percentage of Wastewater - Discharging Facilities Evaluated for the Final
              Rule by Decade Built 	6-15

8-1          Countercurrent Cascade Rinsing	8-5

8-2          Machine Coolant Recycling System 	8-14

8-3          Centrifugation and Recycling of Painting Water Curtains  	8-15

8-4          Electrodialysis Cell 	8-17

8-5          Membrane Filtration Unit  	8-21
                                          xv

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                                                                              List of Figures
                            LIST OF FIGURES (Continued)

                                                                                  Page

8-6          Ion Exchange	8-22

8-7          Chemical Reduction of Hexavalent Chrome	8-35

8-8          Cyanide Destruction Through Alkaline Chlorination  	8-37

8-9          Chemical Reduction / Precipitation of Chelated Metals 	8-40

8-10         Continuous Chemical Emulsion Breaking Unit with Coalescing Plates	8-42

8-1 la        Disk Oil  Skimming Unit  	8-44

8-1 Ib        Belt Oil Skimming Unit   	8-45

8-12         Dissolved Air Flotation Unit	8-47

8-13         Continuous Chemical Precipitation System with Lamella Clarifier 	8-49

8-14         Effect of pH on Hydroxide and Sulfide Precipitation  	8-51

8-15         Center-Feed Rim Flow Clarifier  	8-55

8-16         Multimedia Filtration System 	8-58

8-17          Gravity Thickening	8-60

8-18         Plate-and-Frame Filter Press 	8-61

8-19         Rotary Vacuum Filter	8-62

9-1          End-of-Pipe Treatment Train for Options 1 and 2 Considered for the
             Following Subcategories: General Metals, Metal Finishing Job Shops,
             Non-Chromium Anodizing, Printed Wiring Board, and Steel Forming and
             Finishing 	9-39

9-2          In-Process Water Use Reduction Technologies for Options 2 and 4
             Considered for the Following Subcategories: General Metals, Metal
             Finishing Job Shops,  Non-Chromium Anodizing, Printed Wiring Board,
             and Steel Forming and Finishing	9-40
                                          xvi

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                                                                              List of Figures
                            LIST OF FIGURES (Continued)

                                                                                 Page

9-3          End-of-Pipe Treatment Train for Options 3 and 4 Considered for the
             Following Subcategories: General Metals, Metal Finishing Job Shops,
             Non-Chromium Anodizing, Printed Wiring Board, and Steel Forming
             and Finishing	9-41

9-4          End-of-Pipe Treatment Train for Options 5 and 6 Considered for the
             Following Subcategories: Oily Wastes and Railroad Line Maintenance	9-42

9-5          End-of-Pipe Treatment Train for Option 7 and 8 Considered for the
             Following Subcategories: Oily Wastes, Railroad Line Maintenance,
             Shipbuilding Dry Dock  	9-42

9-6          End-of-Pipe Treatment Train for Options 9 and 10 Considered for
             the Following Subcategories: Railroad Line Maintenance and Shipbuilding
             Dry Dock	9-43

11-1         Relationship Between In-Process and End-of-Pipe Technologies and
             Practices	11-62

11-2         Components of Total Capital Investment  	11-63

11-3         Logic Used to Apply End-of-Pipe Technologies and Practices for the
             Following Subcategories: General Metals, Metal Finishing Job Shops,
             Non-Chromium Anodizing, Printed Wiring Board, and Steel Forming
             and Finishing	11-64

11-4         Logic Used to Apply End-of-Pipe Technologies and Practices for the
             Following SubcategoriesSO: Oily Wastes, Railroad Line Maintenance,
             and Shipbuilding Dry Dock	11-65

11-5         Example Treatment Facility for General Metals Subcategory Direct
             Discharger 	11-66

15-1         MP&M Permitting Process Flow Chart	15-10
                                         xvn

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                                                             1.0 - Summary and Scope of the Regulation

i.o          SUMMARY AND SCOPE OF THE REGULATION

             This section presents a brief overview of the Metal Products and Machinery
(MP&M) Point Source Category, discusses the applicability of the MP&M effluent limitations
guidelines and standards for the category, and presents the applicability interface between the
final rule and other regulations for the metals industry. This section also briefly summarizes the
final rule and describes the Agency's efforts to protect confidential business information. This
section is organized as follows:

             •      Section 1.1- Overview of the MP&M Point Source Category;

             •      Section 1.2- Overlap with other effluent guidelines;

             •      Section 1.3 - Summary of applicability;

             •      Section 1.4- Promulgated effluent limitations guidelines and standards;
                    and

             •      Section 1.5 - Protection of confidential business information.

1.1          Overview of the MP&M Point Source Category

             The MP&M Point Source Category includes facilities that discharge wastewater
from processing metal parts, metal products, and machinery.  This processing can be described
by two types of activities: manufacturing and rebuilding/maintenance. Manufacturing is the
series of unit operations necessary to produce metal products and is generally performed in a
production environment. Rebuilding/maintenance 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 and maintenance
operations are intended to keep metal products in operating condition and can be performed in
either a production or a nonproduction environment. The MP&M Point Source Category
encompasses manufacturing, rebuilding, or maintenance of metal parts, products, or machines for
use in the following industrial sectors:

             •      Aerospace;
             •      Aircraft;
             •      Bus and Truck;
             •      Electronic Equipment;
             •      Hardware;
             •      Household Equipment;
             •      Instruments;
             •      Mobile Industrial Equipment;
             •      Motor Vehicle;
             •      Office Machine;
                                          1-1

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                                                               1.0 - Summary and Scope of the Regulation

              •       Ordnance;
              •       Precious Metals and Jewelry;
              •       Railroad;
              •       Ships and Boats;
              •       Stationary Industrial Equipment; and
              •       Miscellaneous Metal Products.

              EPA also evaluated manufacturing, rebuilding, or maintenance of metal parts,
products, or machines used in two other industrial sectors (Job Shops and Printed Wiring Board)
but has decided not to regulate them as part of the final rule.

              These sectors considered by EPA for regulation manufacture, maintain, and
rebuild metal products under more than 200 different Standard Industrial Classification (SIC)
codes. Appendix A includes a list of example SIC codes and North American Industrial
Classification System (NAICS)  codes that apply to the above industrial sectors.  EPA is not
revising limitations and standards for three proposed industrial sectors (i.e., job shops, printed
wiring board, and steel forming and finishing).

              The final rule does  not apply to maintenance or repair of metal parts, products, or
machines that takes place only as ancillary activities at facilities not included in the 16 MP&M
industrial sectors. EPA estimates that these ancillary repair and maintenance activities would
typically discharge de minimis quantities of process wastewater. For example, wastewater
discharges from repair of metal  parts at oil and gas extraction facilities (40 CFR 435) are not
subject to the final rule.  The Agency has determined that permit writers are establishing limits
using best professional judgment (BPJ) to regulate wastewater discharges from ancillary waste
streams for direct dischargers (see 66 FR 433).

              Facilities in any one of the 16 industrial sectors in the MP&M Point Source
Category are subject to the final rule only if they directly discharge process wastewater resulting
from one or more of the following "oily operations:"

              •       Abrasive Blasting;
              •       Adhesive Bonding;
              •       Alkaline  Cleaning for Oil Removal;
              •       Alkaline  Treatment Without Cyanide;
              •       Aqueous  Degreasing;
              •       Assembly/Disassembly;
              •       Burnishing;
              •       Calibration;
              •       Corrosion Preventative Coating (as specified at 40 CFR 438.2(c) and
                     Appendix C of Part 438);
              •       Electrical Discharge Machining;
              •       Floor Cleaning (in Process Area);
              •       Grinding;
                                           1-2

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                                                               1.0 - Summary and Scope of the Regulation

              •      Heat Treating;
              •      Impact Deformation;
              •      Iron Phosphate Conversion Coating;
              •      Machining;
              •      Painting-Spray or Brush (Including Water Curtains);
              •      Polishing;
              •      Pressure Deformation;
              •      Solvent Degreasing;
              •      Steam Cleaning;
              •      Testing (e.g., hydrostatic, dye penetrant, ultrasonic, magnetic flux);
              •      Thermal Cutting;
              •      Tumbling/Barrel Finishing/Mass Finishing/Vibratory Finishing;
              •      Washing (Finished Products);
              •      Welding;
              •      Wet Air Pollution Control for Organic Constituents; and
              •      Suboperations within the operations listed above (see Section 5.0).

These operations are defined in Appendix B to 40 CFR 438 and also in Section 4.0.

              In addition, the final rule covers process wastewater resulting from associated
rinses that remove materials that the processes listed above deposit on the surface of the work
piece.  The final rule does not apply to direct discharges of wastewaters that are otherwise
covered by other effluent limitations guidelines.

              The final rule also covers direct discharges of process wastewater generated from
oily operations related to maintenance and repair of metal products, parts, and machinery at
military installations (i.e., federal facilities) as well  as facilities  owned or operated by state or
local governments.  For example, the final rule covers direct discharges of process wastewater
generated from oily operations related to maintenance and repair of aircraft, cars, trucks, buses,
tanks (or other armor personnel carriers),  and industrial equipment. These operations are
commonly performed at military installations and state or local  government maintenance
facilities. However, the final rule does not apply to wastewater discharges introduced into a
federally owned and operated Treatment Works Treating Domestic Sewage (TWTDS), as
defined at 40 CFR 122.2.

              The MP&M Point Source Category evaluated for the final rule encompasses more
than 41,000 facilities that manufacture, rebuild, or maintain metal parts, products, or machines
for use in the 16 MP&M industrial sectors. Approximately 29,000 of these facilities annually
discharge 5.02 billion gallons of process wastewater. Of the facilities discharging process
wastewater, EPA estimates that 91.6 percent are indirect dischargers, 8.4 percent are direct
dischargers, and 0.1 percent discharge both directly and indirectly. The Agency estimates that
the remaining facilities (an  estimated 12,000) fall into one of three categories:
                                            1-3

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                                                               1.0 - Summary and Scope of the Regulation

              •      Zero discharge.  A zero-discharging facility does not discharge pollutants
                     to waters of the United States or to a POTW. Included in this definition
                     are discharge or disposal of pollutants by way of evaporation, deep-well
                     injection, off-site transfer to a treatment facility, and land application.

              •      Non-water-using. A non-water-using facility does not use process
                     wastewater (i.e., water that comes into direct contact with or results from
                     the production or use of any raw material, intermediate product, finished
                     product, by-product, or waste product) at its oily operation.

              •      Contract haulers. Contract hauling is the removal of any waste stream
                     from a facility by a company authorized to transport and dispose of the
                     waste, excluding discharges to sewers or surface waters.

              The MP&M final rule does not regulate indirect dischargers and discharges to
federally owned and operated TWTDS. There are approximately 2,400 direct dischargers
regulated by the MP&M final rule.

              MP&M sites evaluated for the final rule perform a wide variety of process unit
operations on metal parts, products, or machines.  In general, MP&M unit operations can be
characterized as belonging to one of the following types of unit operations:

              •      Assembly/disassembly operations;
              •      Metal shaping operations;
              •      Organic chemical deposition operations;
              •      Surface finishing operations; and
              •      Surface preparation operations.

              EPA also evaluated the following types of unit operations but has decided not to
regulate them as part of the final rule:

              •      Dry dock operations; and
              •      Metal deposition operations.

Specifically, EPA decided not to regulate "metal-bearing operations"  as defined in 40 CFR
438.2(d) and Appendix C to Part 438. The list of unit operations not regulated by the final rule is
also given in Section 4.0.

              At a given MP&M facility, the specific unit operations performed and the
sequence of those operations depend on many factors, including the activity (i.e., manufacturing,
rebuilding, or maintenance), industrial sector, and type of product processed.  The extent to
which a facility uses process water for these unit operations also varies from site to site.
                                            1-4

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                                                             1.0 - Summary and Scope of the Regulation

             The approximately 2,400 sites regulated by the MP&M final rule discharge
approximately 267 million gallons of process wastewater per year. This wastewater typically
contains total suspended solids, oil and grease, and organic pollutants. MP&M wastewater may
also contain some metals (e.g., zinc, tin, aluminum), often in suspended or particulate phase.

1.2          Overlap with Other Effluent Guidelines

             EPA has previously established effluent limitations guidelines and standards for
13 industries that may perform unit operations or process parts that are sometimes found at
MP&M sites. These effluent guidelines are:

                    Electroplating (40 CFR 413);
                    Iron and Steel Manufacturing (40 CFR 420);
             •      Nonferrous Metals Manufacturing (40 CFR 421);
                    Ferroalloy Manufacturing (40 CFR 424);
                    Metal Finishing (40 CFR 433);
                    Battery Manufacturing (40 CFR 461);
                    Metal Molding and Casting (40 CFR 464);
                    Coil Coating (40 CFR 465);
                    Porcelain Enameling (40 CFR 466);
             •      Aluminum Forming (40 CFR 467);
                    Copper Forming (40 CFR 468);
             •      Electrical and Electronic Components (40 CFR 469); and
             •      Nonferrous Metals Forming & Metal Powders (40 CFR 471).

             In 1986, the Agency reviewed coverage of these regulations and identified a
significant number of metals-processing facilities discharging wastewater that these 13
regulations did not cover.  Based on this review, EPA performed a more detailed analysis of
these unregulated  sites and identified the discharge of significant amounts of pollutants (see
Section 1.1 of the  rulemaking record, DCN M432).  This analysis resulted in the decision to
develop national limitations guidelines and standards for the "Metal Products and Machinery"
(MP&M) Point Source Category (see Section 2.2.5).

             Table 1-1 summarizes the coverage of industrial operations by each MP&M
subcategory for which EPA proposed regulations. Additionally, the MP&M final rule does not
apply to process wastewaters from metal-bearing operations (as defined at §438.2(d) and
Appendix C of Part 438) or process wastewaters that are subject to the limitations and standards
of other effluent limitations guidelines (e.g., Metal Finishing (40 CFR 433) or Iron and Steel
Manufacturing (40 CFR 420)).
                                          1-5

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                                                            1.0 - Summary and Scope of the Regulation
                                      Table 1-1
          Clarification of Coverage by Proposed MP&M Subcategory
Proposed Subcategory
General Metals (Including
Continuous Electroplaters)
Metal Finishing Job Shops
Non-Chromium Anodizing
Printed Wiring Board
(Printed Circuit Board)
Steel Forming and Finishing"
Oily Wastes
Railroad Line Maintenance
Shipbuilding Dry Dock
Continue to
Cover Under
40 CFR 413
(Electroplating)
Existing indirect
dischargers covered by
Part 413.
Existing indirect
dischargers covered by
Part 413.
Existing indirect
dischargers covered by
Part 413.
Existing indirect
dischargers covered by
Part 413.
NA
NA
NA
NA
Continue to
Cover Under
40 CFR 433
(Metal Finishing)
New and existing
direct and indirect
dischargers covered
by Part 43 3.
New and existing
direct and indirect
dischargers covered
by Part 43 3.
New and existing
direct and indirect
dischargers covered
by Part 43 3.
New and existing
direct and indirect
dischargers covered
by Part 43 3.
NA
NA
NA
NA
Cover Under
40 CFR 438
(Metal Products &
Machinery)
None
None
None
None
None
All new and existing
direct dischargers
(see 438. 10).
None
None
NA - Not applicable.
aThese facilities will remain subject to 40 CFR 420.
                                         1-6

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                                                              1.0 - Summary and Scope of the Regulation

1.3           Summary of Applicability

              The MP&M effluent limitations guidelines and standards regulate process
wastewater from oily operations at existing or new direct dischargers engaged in manufacturing,
rebuilding, or maintenance of metal parts, products, or machines used in any of the 16 industrial
sectors listed in Section 1.1. The guidelines and standards do not apply to wastewater from oily
operations in certain circumstances (e.g., if they are subject to other national effluent limitations
or standards).  The MP&M regulation does not regulate any of the other subcategories for which
it proposed regulations. These subcategories are the General Metals, Metal Finishing Job Shops,
Non-Chromium Anodizing, Printed Wiring Board, Steel Forming and Finishing, Railroad Line
Maintenance, and Shipbuilding Dry Dock. Process wastewater is defined in §438.2.

              EPA defines process wastewater for the final rule to include wastewater
discharges from oily operations for the manufacturing, rebuilding, or maintenance of metal parts,
products, or machinery for use in any of the 16 MP&M industrial sectors and wastewater from air
pollution control devices.

              EPA notes that direct discharges resulting from the washing of cars, aircraft, or
other vehicles, when performed as a prepatory step prior to one or more successive
manufacturing, rebuilding, or maintenance operations, are subject to the MP&M rule.

              Nonprocess wastewater discharges are not subject to the final rule. Nonprocess
wastewater means sanitary wastewater,  noncontact cooling water, water from laundering, and
noncontact stormwater. Nonprocess wastewater for this part also includes  wastewater discharges
from nonindustrial sources such as residential housing, schools, churches, recreational parks,
shopping centers as well as wastewater  discharges from gas stations, utility plants, and hospitals.

              In addition to nonprocess wastewater, the final rule does not apply to wastewater
generated from: (1) gravure cylinder and metallic platemaking conducted within or for printing
and publishing facilities; (2) the washing of cars, aircraft  or other vehicles when it is performed
only for aesthetic/cosmetic purposes; (3) MP&M operations at gasoline stations (SIC Code 5541)
or vehicle rental facilities (SIC Codes 7514 or 7519); or (4) unit operations performed by drum
reconditioners/refurbishers to prepare metal drums for reuse.

              As noted, EPA is also not promulgating limitations and standards for facilities in
the proposed Shipbuilding Dry Dock Subcategory. The final rule does not cover wastewater
generated on-board ships and boats when they are afloat (that is, not in dry docks or similar
structures), flooding water,  and dry dock ballast water (see 66 FR 445). For U.S. military ships,
EPA is in the process of establishing standards to regulate discharges of wastewater generated
on-board these ships when they are in U.S. waters and are afloat under the Uniform National
Discharge Standards (UNDS) pursuant to section 312(n) of the Clean Water Act (CWA) (see 64
FR25125, May 10, 1999).
                                           1-7

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                                                               1.0 - Summary and Scope of the Regulation

              Finally, as previously stated, the final rule does not apply to maintenance or repair
of metal parts, products, or machines that takes place only as ancillary activities at facilities not
included in the 16 MP&M industrial sectors.

              See Section 15.0 for a more detailed discussion regarding applicability.

1.4           Promulgated Effluent Limitations Guidelines and Standards

              EPA proposed effluent limitations and standards for eight subcategories.
However, for reasons discussed in Section 9.0 and Section VI of the preamble to the final rule,
the final rule establishes effluent limitations guidelines and standards  for new and existing direct
dischargers in one subcategory: Oily Wastes.

              EPA may divide a point source category (e.g., MP&M) into groupings called
"subcategories" to provide a method for addressing variations between products, raw materials,
processes, and other factors that result in distinctly different effluent characteristics. Regulation
of a category using subcategories allows each subcategory to have a uniform set of effluent
limitations that take into account technological achievability and economic impacts unique to
that subcategory.  Grouping similar facilities into subcategories increases the likelihood that the
regulations are practicable, and diminishes the need to address variations between facilities
through a variance process. The CWA requires EPA, in developing effluent limitations
guidelines and pretreatment standards, to consider a number of different subcategorization
factors. (See Section 6.0 for a list of the factors considered for the final MP&M rule and a
detailed discussion of subcategorization.)

              EPA is promulgating concentration-based limits and standards for direct
dischargers for the Oily Wastes Subcategory. However, the CWA authorizes permit writers to
decide when it is most appropriate to implement mass-based limits. Guidance for setting limits
is included in Section 15.0.

              Table 1-2 summarizes the regulatory levels of control and selected technology
bases EPA used in promulgating the limitations and standards presented in Table 1-3, Section
14.0,  and 40 CFR 438, Subpart A (Oily Wastes Subcategory). Section 15.0 provides guidance to
permit writers.
                                            1-8

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                                                           1.0 - Summary and Scope of the Regulation
                                     Table 1-2
    Technology Bases for Promulgated MP&M Limitations and Standards
Subcategory
Oily Wastes
Regulatory Level
BPT/BCT/NSPS
BAT
PSES/PSNS
Selected Technology Option
Pollution prevention; chemical emulsion breaking and
oil/water separation (Option 6). See Section 9.7.
No limitations established under Part 438.
No standards established under Part 438.
                                     Table 1-3

    Effluent Limitations Guidelines for the MP&M Point Source Category
                                   (40 CFR 438)
BPT/BCT/NSPS - Oily Wastes Subcategory
Regulated Parameter
Total Suspended Solids (TSS)
Oil and Grease (as HEM)
pH
Maximum Daily
mg/L (ppm)
62
46
a
discharges must remain within the pH range 6 to 9.

1.5          Protection of Confidential Business Information

             Whenever EPA is required to develop effluent limitations, pretreatment standards,
or other standards, Section 308(a) of the  CWA authorizes the Agency to require owners or
operators of point sources to provide certain information. Various statutes under which EPA
operates contain special provisions concerning the entitlement to confidential treatment of certain
business information (CBI). In compliance with these statutes and EPA's implementing
regulations, the Agency has withheld CBI from the public record in the Water Docket, but retains
CBI in the nonpublic version of the rulemaking record. In addition, the Agency has withheld
from disclosure some data not claimed as CBI because the release of these data could indirectly
reveal CBI. Furthermore, EPA has aggregated certain data in the public record, masked facility
identities, or used other strategies to prevent the disclosure of CBI. The Agency's approach to
CBI protection ensures that the  data in the public record both explain the basis for the final rule
and provide the opportunity for public comment, without compromising data confidentiality.
                                         1-9

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                                                                             2.0 - Background

2.0           BACKGROUND

              This section presents background information supporting the development of
effluent limitations guidelines and standards for the Metal Products and Machinery (MP&M)
Point Source Category. Section 2.1 presents the legal authority to regulate the MP&M industry.
Section 2.2 discusses the Clean Water Act, Pollution Prevention Act, Regulatory Flexibility Act
(as amended by the Small Business Regulatory Enforcement Fairness Act of 1996), and prior
regulation of the metals industry.

2.1           Legal Authority

              EPA is promulgating these regulations under the authority of Sections 301, 304,
306, 307, 308, 402, and 501 of the Clean Water Act, 33 U.S.C. 1311, 1314, 1316, 1317, 1318,
1342, and 1361 and under authority of the Pollution Prevention Act of 1990 (PPA), 42 U.S.C.
13101 et seq., Public Law 101-508, November 5, 1990.

2.2           Regulatory Background

2.2.1         Clean Water Act

              Congress adopted the Clean Water Act (CWA) to "restore and maintain the
chemical, physical, and biological integrity of the Nation's waters" (Section 101(a), 33 U.S.C.
1251(a)). To achieve this  goal, the CWA prohibits the discharge of pollutants into navigable
waters  except in compliance with the statute. The CWA confronts the problem of water pollution
on a number of different fronts. Its primary reliance, however, is on establishing restrictions on
the types and amounts of pollutants discharged from various industrial, commercial, and public
sources of wastewater.

              Congress recognized that regulating only those sources that discharge effluent
directly into the nation's waters would not be sufficient to achieve the CWA's goals.
Consequently, the CWA requires  EPA to promulgate  nationally applicable pretreatment
standards that restrict pollutant discharges for those who discharge wastewater indirectly through
sewers flowing to publicly owned treatment works (POTWs) (Sections 307(b) and (c), 33 U.S.C.
1317(b) and (c)).  National pretreatment standards are established for those pollutants in
wastewater from indirect dischargers that may pass through  or interfere with POTW operations.
Generally, pretreatment standards are designed to ensure that wastewater from direct and indirect
industrial dischargers are  subject to similar levels of treatment. In addition, EPA requires
POTWs to implement local  pretreatment limits applicable to their industrial indirect dischargers
to satisfy any local requirements (40 CFR 403.5).

              Direct dischargers  must comply with effluent limitations in National Pollutant
Discharge Elimination System ("NPDES") permits; indirect dischargers must comply with
pretreatment standards. EPA establishes these limitations and standards by regulation for
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categories of industrial dischargers and bases them on the degree of control that can be achieved
using various levels of pollution control technology.

              1.      Best Practicable Control Technology Currently Available (BPT)
                     (Section 304(b)(l) of the CWA)

                     BPT effluent limitations guidelines are applicable to direct dischargers
                     (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 facilities of various sizes, ages, unit processes or
                     other common characteristics within the category or subcategory for
                     control of conventional, priority, and nonconventional pollutants. Section
                     304(a)(4) designates the following as conventional pollutants:
                     biochemical oxygen demand (BOD5), 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).  EPA
                     has identified 65 pollutants and classes of pollutants as toxic pollutants, of
                     which 126 specific substances have been designated priority toxic
                     pollutants.  See Appendix A to Part 403 (reprinted after 40 CFR 423.17).
                     All other pollutants are considered to be nonconventional.

                     In establishing BPT effluent limitations guidelines, EPA first considers the
                     total cost of applying the control technology in relation to the effluent
                     reduction benefits. The Agency also considers the age of the equipment
                     and facilities involved, the processes employed and any required process
                     changes,  engineering aspects of the control technologies, non-water quality
                     environmental impacts (including energy requirements), and such other
                     factors as the EPA Administrator deems appropriate (CWA 304(b)(l)(B)).
                     Traditionally, EPA establishes BPT effluent limitations based on the
                     average of the best performances  of facilities within the industry of various
                     ages, sizes, processes or other common characteristics.  Where existing
                     performance is uniformly inadequate, EPA may require higher levels of
                     control than are currently in place in  an industrial category if the Agency
                     determines that the technology can be practically applied.

              2.      Best Conventional Pollutant Control Technology (BCT)
                     (Section 304(b)(4) of the CWA)

                     The 1977 amendments to the CWA established BCT for discharges of
                     conventional pollutants from existing industrial point sources.  BCT
                     effluent limitations guidelines are applicable to direct discharging sites. In
                     addition to other factors specified in  Section 304(b)(4)(B), the CWA
                     requires that EPA establish BCT limitations after consideration of a two-
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                                                                2.0 - Background

       part "cost-reasonableness" test. EPA explained its methodology for the
       development of BCT limitations in 1986 (51 FR 24974; July 9, 1986).

3.      Best Available Technology Economically Achievable (BAT)
       (Sections 304(b)(2) of the CWA)

       BAT effluent limitations guidelines are applicable to direct discharging
       sites.  In general, BAT effluent limitations guidelines represent the best
       available economically achievable performance of plants in the industrial
       subcategory or category. The CWA 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 cost of achieving BAT effluent
       reductions, the age of equipment and facilities involved, the processes
       employed, potential process changes, non-water quality environmental
       impacts (including energy requirements), and such factors as the
       Administrator deems appropriate.  The Agency retains considerable
       discretion in assigning the weight to be accorded to these factors. As with
       BPT, where existing performance is uniformly inadequate, EPA may base
       BAT upon technology transferred from a different subcategory within an
       industry or from another industrial category. In addition, BAT may
       include process changes or internal controls, even when these technologies
       are not common industry practice.

4.      New Source Performance Standards (NSPS)
       (Section 3 06 of the CWA)

       NSPS are applicable to new direct discharging sites and are based on the
       best available demonstrated treatment technology. New facilities have the
       opportunity to install the best and most efficient production processes and
       wastewater treatment technologies. As a result, NSPS should represent the
       greatest degree of effluent reduction attainable through the application of
       the best available demonstrated control technology for all pollutants (i.e.,
       conventional, nonconventional, and priority pollutants). In establishing
       NSPS, the CWA directs EPA to take into consideration the cost of
       achieving the effluent pollutant reduction and any non-water quality
       environmental impacts (including energy requirements).

5.      Pretreatment Standards for Existing Sources (PSES)
       (Section 307(b) of the CWA)

       PSES are applicable to indirect discharging sites (i.e., sites that discharge
       to a POTW). The CWA requires PSES for pollutants that pass through,
       interfere with, or are otherwise incompatible with POTW treatment
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                    processes or sludge disposal methods. The CWA specifies that
                    pretreatment standards are to be technology-based and analogous to the
                    BAT effluent limitations guidelines.

                    The General Pretreatment Standards, which set forth the framework for
                    implementing categorical pretreatment standards, are found at 40 CFR
                    403.

             6.     Pretreatment Standards for New Sources (PSNS)
                    (Section 307(c) of the CWA)

                    PSNS are applicable to new 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 have the opportunity to incorporate into their plants 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 and the pollutants controlled.

                                      Table 2-1

                    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
BCT
X



BCT


X
BAT
X



BAT
X
X

NSPS

X


NSPS
X
X
X
PSES


X

PSES
X
X

PSNS



X
PSNS
X
X

Source: Clean Water Act.

             EPA typically does not establish pretreatment standards for conventional
pollutants (e.g., BOD5, TSS, oil and grease) since POTWs are designed to treat these pollutants,
but EPA has exercised its authority to establish categorical pretreatment standards for
conventional pollutants as surrogates for toxic or nonconventional pollutants or to prevent
interference. For example, EPA established categorical pretreatment standards for new and
existing sources with a one-day maximum concentration of 100 mg/L oil and grease in the
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Petroleum Refining Point Source Category (40 CFR 419) to "minimize the possibility of slug
loadings of oil and grease being discharged to POTWs" (see Section 24.4 of the rulemaking
record, DCN 17949).

2.2.2          Section 304(m) Requirements

              Section 304(m) of the CWA, added by the Water Quality Act of 1987, requires
EPA to establish schedules for: (1) reviewing and revising existing effluent limitations guidelines
and standards; and (2) promulgating new effluent guidelines. On January 2, 1990, EPA published
an Effluent Guidelines Plan (see 55 FR 80), in which schedules were established for developing
new and revised effluent guidelines for several industry categories, including the metal products
and machinery industry.

              Natural Resources Defense Council, Inc. (NRDC) and Public Citizen, Inc.
challenged the Effluent Guidelines Plan in a suit filed in the U.S. District Court for the District of
Columbia, (NRDC et al v. Browner, Civ. No. 89-2980). On January 31, 1992, the Court entered a
consent decree (the "304(m) Decree"), which  establishes schedules for, among other things,
EPA's proposal and promulgation of effluent guidelines for a number of point source categories.
The consent decree, as amended, requires EPA to take final  action on the Metal Products and
Machinery effluent guidelines by February 14, 2003.

2.2.3          Pollution Prevention Act

              The Pollution Prevention Act of 1990 (PPA) (42 U.S.C. 13101 et seq., Public Law
101-508, November 5, 1990) "declares it to be the national policy of the United States that
pollution should be prevented or reduced whenever feasible; pollution that cannot be prevented
should be recycled in an environmentally safe manner, whenever feasible; pollution that cannot
be prevented or 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. 13101 (b)). In short, preventing pollution before it is created is preferable to
trying to manage, treat or dispose of it after it is created. 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(b)(2)). EPA reviewed
this effluent guideline for its incorporation of pollution prevention.

              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 "include[s]  equipment or technology modifications, process
or procedure modifications, reformulation 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." 42 U.S.C. 13102(5). In effect, source reduction  means reducing the
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                                                                              2.0 - Background

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.

              EPA gathered information on pollution prevention practices used by the MP&M
industry from site visits, survey responses, and other references.  Typical pollution prevention
practices include reducing water use, extending the life of process bath constituents, or adding
recycle or reuse technologies. See Section 8.0 for a detailed discussion of these practices.  EPA
supports pollution prevention technology by including pollution prevention in its technology
bases for the final MP&M effluent limitations and new source performance standards.  This
includes water conservation and reuse of lubricants and solvents.  Technology options
considered, as well as selected, as the basis for the MP&M effluent limitations guidelines and
standards include pollution prevention practices and are discussed in Section 9.0.

2.2.4          Regulatory Flexibility Act (RFA) as Amended by the Small Business
              Regulatory Enforcement Fairness Act of 1996 (SBREFA)

              The RFA generally requires an agency to prepare a regulatory flexibility analysis
of any  rule subject to notice and comment rulemaking requirements under the Administrative
Procedure Act or any other statute unless the agency certifies that the rule will not have a
significant economic impact on a substantial number of small entities. Small entities include
small businesses, small organizations, and small governmental jurisdictions.

              For assessing the impacts of the final rule on small entities, a small entity is
defined as: (1) a small business according to the Regulations of the Small Business
Administration (SBA) at 13 CFR 121.201, which define small businesses for Standard Industrial
Classification (SIC) codes; (2) a small governmental jurisdiction that is a government of a city,
county, town, school district or special district with a population of less than 50,000; and (3) a
small organization that is any not-for-profit enterprise that is independently owned and operated
and is not dominant in its field.

              In accordance with Section 603 of the RFA, EPA prepared an initial  regulatory
flexibility analysis (TRFA) for the proposed rule and convened a Small Business Advocacy
Review Panel to obtain advice and recommendations of representatives of the regulated small
entities in accordance with Section 609(b) of the RFA (see 66 FR 519).  The results of IRFA are
provided in Chapter 10 of the Economic, Environmental, and Benefits Analysis (EEBA) (EPA-
821-B-03-002). The January 2001 proposed rule (see 66 FR 523) presents a summary of the
Panel's recommendations and the full Panel Report (see Section  11.2, DCN 16127) presents a
detailed discussion of the Panel's advice and recommendations.

              A regulatory flexibility analysis addresses:

              •      The need for, objectives of, and legal basis for a rule.
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                                                                               2.0 - Background

              •       A description of, and where feasible, an estimate of the number of small
                     entities to which a rule would apply.

              •       The projected reporting, recordkeeping, and other compliance requirements
                     of a rule, including an estimate of the classes of small entities that would
                     be subject to a rule and the types of professional skills necessary for
                     preparation of the report or record.

              •       An identification, where practicable,  of all relevant federal rules that may
                     duplicate, overlap, or conflict with a rule.

              •       A description of any significant regulatory alternatives to a rule that
                     accomplish the stated objectives of applicable statutes and that minimize
                     any significant economic impact of a rule on small entities.  Consistent
                     with the stated objectives of the CWA, the analysis discusses significant
                     alternatives such as:

                            Establishing differing compliance or reporting requirements or
                            timetables that take into account the resources available to small
                            entities.

                            Clarifying, consolidating, or simplifying compliance and reporting
                            requirements under the rule for such small entities.

                            Using performance rather than design standards.

                            Excluding from coverage of a rule, or any part thereof, such small
                            entities.  Based on the regulatory flexibility analysis and other
                            factors, EPA considered an exclusion to eliminate disproportionate
                            impacts on small businesses, which reduced the number of small
                            businesses that would be affected by a rule.

              The Small Business Advocacy Review Panel comprised representatives from three
federal agencies: EPA, the Small Business Administration, and the Office of Management and
Budget. The Panel reviewed materials EPA prepared in connection with the proposed rule IRFA,
and collected the advice and recommendations of small entity representatives. For the Small
Business Advocacy Review Panel, the  small entity representatives included nine small MP&M
facility owner/operators, one small municipality, and these six trade associations representing
different sectors of the industry:

              •       National Association of Metal Finishers (NAMF)/Association of
                     Electroplaters and Surface Finishers (AESF)/MP&M Coalition;

              •       Association Connecting Electronics Industries (also known as IPC);
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                                                                             2.0 - Background

             •      Porcelain Enamel Institute;

             •      American Short Line Railroad Association (ASLRA);

             •      Electronics Industry Association (EIA); and

             •      American Wire Producers Association (AWPA).

             The Panel provided background information and analysis to the small entity
representatives and conducted meetings with the representatives. The Panel asked the small entity
representatives to submit written comment on the MP&M proposed rule in relation to the
elements of the proposal IRFA. The Panel carefully considered these comments when developing
their recommendations. The Panel's report summarizes their outreach to small entities and the
comments submitted by the small  entity representatives. The Panel's report also presented their
findings on issues related to the elements of the proposal IRFA and recommendations regarding
the rulemaking. Based on this input, EPA made several changes to the January 2001 proposal
that reduced the number of small entities regulated and the level of impact to small entities that
remain within the scope of the regulation.

             In the final rule, EPA excluded direct dischargers in seven of eight proposed
subcategories and indirect dischargers in all eight proposed subcategories. Consequently, EPA
excluded most small entities from additional regulation (see Section VI of the MP&M preamble
to the final rule and Chapter 10 of the EEBA). To assess the potential economic impact of the
final rule on small entities regulated by the final rule, EPA drew on: (1) a comparison of
compliance costs to revenue; and (2) the firm and facility impact analyses discussed in Chapters 9
and 10 of the EEBA.

             First, EPA performed an analysis comparing annualized compliance costs to
revenue for small entities at the firm level.  EPA found that none of the small firms are estimated
to incur compliance costs equaling or exceeding one percent of annual revenue. Second, EPA
drew on the facility impact analysis, which estimated facility closures and other adverse changes
to financial condition (referred to as "moderate impacts"). See Chapter 5 of the EEBA for  details
of EPA's analysis of closures and  moderate impacts for privately owned businesses. This analysis
indicated that the final rule would cause no regulated facilities owned by small entities to close or
to incur moderate impacts. From these analyses, EPA determined that the final rule will not have
a significant economic impact on a substantial number of small entities. See Chapter 10 of the
EEBA for the final rule for a more detailed discussion of the economic impacts on small entities.

2.2.5        Regulatory History of the  Metals Industry

             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.
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                                                                             2.0 - Background
                                       Table 2-2
                Summary of Metals Industry Effluent Guidelines
Coverage Area
Metal and Metal Alloy
Manufacturing
Metal Forming
Component Finishing
Title
Iron and Steel Manufacturing"
Nonferrous Metals Manufacturing
Ferroalloy Manufacturing
Iron and Steel Manufacturing8
Metal Molding and Casting
Aluminum Forming
Copper Forming
Nonferrous Metals Forming and Metal Powders
Electroplating
Iron and Steel Manufacturing8
Metal Finishing
Battery Manufacturing
Coil Coating
Porcelain Enameling
Electrical and Electronic Component Manufacturing
CFR Reference
40 CFR 420
40 CFR 421
40 CFR 424
40 CFR 420
40 CFR 464
40 CFR 467
40 CFR 468
40 CFR 471
40 CFR 413
40 CFR 420
40 CFR 43 3
40 CFR 461
40 CFR 465
40 CFR 466
40 CFR 469
Source: Code of Federal Regulations. Part 40.
The Iron and Steel Manufacturing category includes metal manufacturing, metal forming, and component finishing.

             In 1986, the Agency reviewed these 13 regulations and identified a significant
number of metals-processing facilities discharging wastewater that these regulations did not
cover. Based on this review, EPA performed a detailed analysis of these unregulated sites and
identified the discharge of significant amounts of pollutants. This analysis resulted in a
preliminary decision to consider new regulations for a 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 located in the MP&M Public Record (Section 1.1, DCN
M432). The preliminary study of the unregulated MP&M facilities indicated the following:

             •       The number of facilities, wastewater flow, and toxic and nonconventional
                     pollutant loads were significant;

             •       The large quantities of toxic pollutants discharged threatened the treatment
                     capability of many POTWs as found by the Domestic Sewage Study;

             •       There were gaps in federal regulatory coverage in the electroplating, metal
                     finishing, and electrical and electronic components categories;

             •       Pollutant concentrations were at treatable levels and at levels as high and
                     sometimes higher than concentrations in wastewater from other regulated
                     categories;  and
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                                                                             2.0 - Background

             •      Some MP&M operations generate hazardous solid waste and sludge that
                    could impact hazardous waste disposal.

             Based on information contained in the PDS, EPA divided the MM&R category
into two phases by major industrial groups or sectors.  The Agency announced its schedule for the
development of effluent guidelines for two separate MM&R phases in EPA's  January 2, 1990
Effluent Guidelines Plan (55 FR 80). One of the primary reasons for dividing the category into
two phases was the large number of facilities (over 900,000) identified in the PDS as potentially
included in the MM&R Point Source Category. 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). Many 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 more
accurately describes  the coverage of the category.

             As mentioned in Section 2.2.2, 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. Browner, Civ. No. 89-2980). Under a consent decree in this litigation, EPA developed a
plan to promulgate effluent guidelines for, among others, the MP&M Point Source Category.
The 1992 Effluent Guidelines Plan provided for EPA to propose effluent guidelines for the
MP&M Phase I Category by November 1994 and take final  action by May 1996.  Based on a
motion filed by EPA on September 28, 1994, the court granted an extension for proposal and
promulgation of the final regulation. To make the regulation more manageable, EPA initially
divided the industry  into two phases based on industrial sectors.  The Phase I proposal included
the following industry sectors: Aerospace; Aircraft; Electronic Equipment; Hardware; Mobile
Industrial Equipment; Ordnance; and Stationary Industrial Equipment. At that time, EPA
planned to propose a rule for the Phase U sectors approximately three years after the MP&M
Phase I proposal.  Phase II sectors included:  Bus & Truck, Household Equipment, Instruments,
Job Shops, Motor Vehicles, Office Machines, Precious Metals and Jewelry, Printed Wiring
Boards, Railroad,  Ships and Boats, and Miscellaneous Metal Products.

             On May 30, 1995, EPA published the MP&M Phase I proposal (60 FR 28210).
EPA proposed effluent limitations guidelines, pretreatment standards, and new source
performance standards for the seven MP&M Phase I industrial sectors. EPA received over 350
public comments on the Phase I proposal requesting that the Agency combine all MP&M
industrial sectors into one effluent guideline. Commentors raised concerns regarding the
regulation of similar facilities with different compliance schedules and potentially different
limitations solely based on whether they were in a Phase I or Phase U MP&M industrial sector.
Furthermore, many facilities performed work in multiple sectors.  In such cases, permit writers
and control authorities (e.g., POTWs) would need to decide which MP&M rule (Phase I or II)
applied to a facility.

             Based on these comments and after negotiations with NRDC, EPA proposed
merging the two phases into one rule (61 FR 35042; July 3,  1996). In 1997, EPA obtained
approval from the U.S. District Court for the District of Columbia to combine MP&M Phases I

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                                                                              2.0 - Background

and II into a single regulation for the 18 MP&M industrial sectors and to extend the effluent
guidelines schedule (62 FR 8726; February 26, 1997).  Extension of the schedule allowed EPA to
use POTW survey data to develop more precise estimates of administrative burden and allowed
more extensive stakeholder involvement for data collection. Under the Consent Decree as
amended, EPA is required to take final action on the MP&M rule by February 14, 2003.

              EPA published a new proposal on January 3, 2001 (66 FR 424), which completely
replaced the 1995 proposal. EPA proposed to establish new effluent limitations and guidelines
and standards for  18 MP&M industrial sectors (without any designation of "Phase I or IT) and
divided the industry into eight regulatory subcategories: General Metals, Metal Finishing Job
Shops, Printed Wiring Board, Non-Chromium Anodizing, Steel Forming and Finishing, Oily
Wastes, Railroad Line Maintenance, and Shipbuilding Dry Dock (see 66 FR 439 for a discussion
of the proposal subcategorization scheme).

              EPA found two basic types of waste streams in the industry:  (1) wastewater with
high metals content (metal-bearing), and (2) wastewater with low concentration of metals and
high oil and grease content (oil-bearing).  When looking at facilities generating metal-bearing
wastewater (with or without oil-bearing wastewater), EPA identified five groups of facilities that
could potentially be subcategorized by dominant product, raw materials used, and/or nature of the
waste generated (i.e., General Metals, Metal Finishing Job Shops, Printed Wiring Board, Non-
Chromium Anodizing, and Steel Forming and Finishing). When evaluating facilities with only
oil-bearing wastewater for potential further subcategorization, EPA identified two types of
facilities (i.e., Railroad Line Maintenance and Shipbuilding Dry Dock) that were different from
the other facilities in the Oily Wastes Subcategory based on size, location, and dominant product
or activity.  This subcategorization scheme allowed EPA to more accurately assess various
technology options in terms of compliance costs, pollutant reductions, benefits, and economic
impacts.

              EPA proposed new limits and standards for direct dischargers in all eight MP&M
subcategories and proposed pretreatment standards for all indirect dischargers in three
subcategories (i.e., Metal Finishing Job Shops, Printed Wiring Board, and Steel Forming and
Finishing); pretreatment standards for facilities above a certain wastewater flow volume in two
subcategories (i.e., General Metals and Oily Wastes); and no national pretreatment standards for
facilities in three subcategories (i.e., Non-Chromium Anodizing, Railroad Line Maintenance, and
Shipbuilding Dry Dock).  EPA received over 1,500 comment letters on the 2001 proposal.

              On June 5, 2002, EPA published a Notice of Data Availability (NODA) at 67 FR
38752.  In the NOD A, EPA discussed major issues raised in comments on the 2001 proposal;
suggested revisions to the technical and economic methodologies used to estimate compliance
costs, pollutant loadings, and economic and environmental impacts; presented the results of these
suggested methodology changes and incorporation of new (or revised) data; and summarized the
Agency's thinking on how these results could affect the Agency's final decisions.
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                                                                              2.0 - Background

              The NODA also included a discussion of possible alternative options for certain
subcategories based on comments, including an Environmental Management System (EMS)
alternative in lieu of Part 438 limitations and standards, and a discussion of "upgrading" sites
currently regulated under the Electroplating regulations (40 CFR 413) to meet the Metal
Finishing regulations (40 CFR 433) (see 67 FR 38797). Finally, the NODA included preliminary
revised effluent limitations and pretreatment standards for all eight proposed subcategories. EPA
received over 300 comment letters on the NODA. EPA's responses to comments on the May
1995 proposal, January 2001 proposal, and June 2002 NODA can be found in Section 20.3 of the
rulemaking record.
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                                                                       3.0 - Data Collection Activities
3.0
DATA COLLECTION ACTIVITIES
              This section summarizes the Agency's data collection activities for the MP&M
rulemaking effort. Section 3.1 summarizes the 1989 and 1996 MP&M industry questionnaires
including their purpose, recipient selection process, types of information collected, and uses of
data.  Sections 3.2 and 3.3 summarize the site visit and field sampling programs, respectively,
conducted at facilities performing proposed MP&M operations.1 Sections 3.4, 3.5, and 3.6
discuss other data sources.
3.1
Industry Questionnaires
              EPA distributed two screener and six detailed questionnaires (surveys) as part of
the data collection effort for the MP&M rulemaking. As discussed in Section 2.0, EPA initially
divided the MP&M Point Source Category into two phases by major industrial sectors.  The
surveys distributed for the seven Phase I industrial sectors requested data reflecting 1989
operations, and the surveys distributed for the 11 Phase n industrial sectors requested data
reflecting 1996 operations. The table below lists the industry surveys and the distribution dates.
Sections  3.1.1 and 3.1.2 discuss these questionnaire efforts.

                   Distribution of the MP&M Industry Surveys
Type of Survey
Screener

Detailed


Survey Name
1989 Screener Survey
1996 Screener Survey
1996 Benefits Screener
1989 Detailed Survey
1996 Long Detailed Survey
1996 Short Detailed Survey
1996 Municipality Detailed Survey
1996 POTW Detailed Survey
1996 Federal Detailed Survey
Distribution Date
8/90
12/96
10/98
1/91
6/97
9/97
6/97
11/97
4/98
              During the same time that EPA was developing the MP&M Point Source
Category rulemaking, EPA was also updating the effluent limitations guidelines and standards
for the Iron and Steel Point Source Category. As part of the revised Iron and Steel rulemaking,
EPA distributed detailed and short surveys to iron and steel facilities.  Following receipt of the
1997 Iron and Steel Surveys, EPA evaluated whether some facilities may be more appropriately
covered under the MP&M Point Source Category.
'Note: EPA evaluated a number of unit operations for the May 1995 proposal, January 2001 proposal, and June 2002
NODA (see Tables 4-3 and 4-4). However, EPA selected a subset of these unit operations for regulation in the final
rule (see Section 1.0). For this Section, the term "proposed MP&M operations" means those operations evaluated
for the two proposals, NODA, and final rule.  The term "final MP&M operations" means those operations defined as
"oily operations" (see Section 1.0, 40 CFR 438.2(f), and Appendix B to Part 438) and regulated by the final rule.
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                                                                     3.0 - Data Collection Activities

              EPA included data from 154 iron and steel surveys in the MP&M survey database
and proposed to create a new subcategory, the Steel Forming and Finishing Subcategory in the
MP&M Point Source Category (see 66 FR 424). Based on comments on the January 2001
proposal and June 2002 NODA EPA concluded that those operations included in the proposed
Steel Forming and Finishing Subcategory should remain subject to effluent guidelines at the Iron
and Steel Point Source Category (40 CFR 420). See Section 6.0 for further discussion of
subcategorization.

              For this final rule, EPA also evaluated portions of the iron and steel surveys to
determine if continuous electroplaters would be more appropriately covered under the MP&M
Point Source Category, as described in the Notice of Data Availability (NODA) (67 FR 38752;
June 5, 2002). EPA included these facilities in the General Metals Subcategory for evaluating
options for the final rule.  See Section 6.0 for further discussion of this determination.  EPA has
data for 47 continuous electroplating lines at 24 sites.  The data for these lines were evaluated in
developing the final MP&M effluent limitation guidelines and standards (see Section 3.1.3 for
further discussion). A blank copy of the Iron and  Steel Surveys and the relevant data from the 24
surveys  are available in Section 5.3.6, DCN 16147 and Section 15.4.3 of the rulemaking record.

3.1.1          The 1989 Industry Surveys

              EPA distributed a screener and a detailed survey for the Phase I MP&M proposed
regulation to manufacturing, rebuilding, and/or maintenance facilities engaged in the following
seven industrial sectors:

              •      Aerospace;
              •      Aircraft;
              •      Electronic Equipment;
              •      Hardware;
              •      Mobile Industrial Equipment;
              •      Ordnance; and
              •      Stationary Industrial Equipment.

              The 1989 screener and detailed surveys are discussed below.  EPA describes in
detail the recipient selection, stratification schemes, and the type and potential use of the
requested information in the Information Collection Request (ICR) for the 1989 screener and
detailed MP&M industry surveys. The ICR can be found in Section 3.6.2 of the rulemaking
record, DCN M15738.

3.1.1.1        1989 Screener Survey

              In August and September 1990, EPA mailed 8,342 screener surveys (also referred
to as the Mini Data Collection Portfolio (MDCP)) to sites believed to be engaged in
manufacturing, rebuilding, or maintenance activities in one of the seven industrial sectors listed
above.  Mailout of the screener was the preliminary step  in an extensive data-gathering effort for
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                                                                      3.0 - Data Collection Activities

these seven industrial sectors. The purpose of the screener was to identify sites to receive the
more detailed survey and to make a preliminary assessment of these seven industrial sectors.

              1989 Screener Recipient Selection and Distribution

              EPA identified potential recipients from a Dun & Bradstreet database using
Standard Industrial Classification (SIC) codes. The Agency identified more than 190 SIC codes
applicable to the seven industrial sectors listed in Section 3.1.1.  Within each sector, EPA
identified between 1 and 40 SIC codes. EPA calculated the number of sites to receive the
screener within each SIC code by a coefficient of variation (CV) minimization procedure,
described in the Statistical Summary for the Metal Products & Machinery Industry Surveys
(Section 10.0, DCN 16118).  Based on the number of sites selected within each SIC code, the
Agency purchased a list of randomly selected names and addresses from the Dun & Bradstreet
database for each SIC code.  This list included twice the number of sites specified by the CV
minimization procedure for each SIC code.

              EPA deleted sites from the purchased Dun & Bradstreet list for the following
reasons:  sites had SIC codes that were inconsistent with company names; sites were corporate
headquarters without manufacturing, rebuilding, or maintenance operations; or sites had
insufficient mailing addresses.  EPA then randomly selected 30 to 60  sites within each SIC code
and assigned each site a randomly selected identification number. EPA assigned each site
identification number a corresponding barcode to track the distribution and processing of the
screeners.

              To examine trends and similarities in manufacturing across the industry sectors,
EPA also sent  screener surveys to some facilities performing manufacturing in the following
eight industrial sectors:

              •     Bus and Truck;
              •     Household Equipment;
              •     Instruments;
              •     Motor Vehicles;
              •     Office Machines;
              •     Precious and Nonprecious Metals;
              •     Railroad; and
              •      Ships  and Boats.

The Agency did not send the screener to sites whose SIC codes indicated that they were engaged
in only rebuilding or maintenance (i.e., not manufacturing) operations in the eight industrial
sectors listed above.

              EPA maintained a toll-free helpline from August through October of 1990 to
assist screener recipients in completing the survey. This helpline received approximately 900
calls from screener recipients. Additional information about the screener mailing (e.g., a copy of
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                                                                     3.0 - Data Collection Activities

the screener, specific mailing and processing procedures, non-CBI screener responses, follow-up
letters, and notes from helpline telephone conversations) is contained in Sections 3.7, 3.8 and 5.3
of the rulemaking record.

              1989 Screener Mailout Results

              EPA mailed 8,000 screener surveys in August 1990.  Based on the number of
surveys returned undelivered, EPA mailed an additional 342 in September 1990. In addition,
EPA received 22 unsolicited responses to the survey. Of the 8,364 potential respondents to the
screener, including those who provided unsolicited responses, 7,846 received the screener.
Screeners for the remaining 518 were returned to EPA as undeliverable. EPA assumed these
sites to be out of business.  Of the total potential respondents, 84 percent (6,981) returned the
screener to EPA.  A blank copy of the screener form and nonconfidential portions of the
completed screeners are contained in the rulemaking record (see Section 3.7.2, DCN 17223, and
Sections 3.7.1  and 5.3.7). Table 3-1 and Figure 3-1  summarize the mailout results for the 1989
and 1996 survey efforts.

              Information Collected

              The Agency requested the following site-specific information in the 1989
screener:

              •      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;
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                                                                 Table 3-1
                                                                                                                         3.0 - Data Collection Activities
                                         1989 and  1996 MP&M Survey Mailout Results
Survey Type
1989 Screener Survey
1989 Detailed Survey
1996 Screener Survey
1996 Benefits Screener
1996 Long Detailed Survey
1996 Short Detailed Survey
1996 Municipality Detailed
Survey
1996 Federal Detailed Survey
Mailed
8,342
1,020
5,325
1,750
353
101
150
-
Returned
Undelivered
518
0
579
155
1
1
2
-
Returned
(%)
6,98P(84)
998b (98)
4,248d (80)
1,392 (80)
311b(88)
83 (82)
147 (98)
51 (-)
Not
Returned
(%)
865(11)
22(2)
497 (10)
161 (10)
41 (12)
17(17)
1(1)
-
Respondents
Performing Proposed
MP&M Operations
(%)
3,598 (52)
792 (79)
2,424 (57)
1,354 (97)
303C (97)
59(71)
144 (53)f
44 (86)
Respondents Not Performing
Proposed MP&M Operations
and Respondents Performing
only Dry Proposed MP&M
Operations (%)
3,373 (48)
199 (20)e
1,824 (43)
38(3)
8(3)e
24 (29)
3 (47)f
7(14)
Source: 1989 and 1996 Survey Tracking Systems (see Section 8.8.1, DCN 16331, and Section 5.3, DCN 16330 of the rulemaking record).
includes 22 unsolicited responses.
bSeven of the 1989 detailed surveys and two of the 1996 long detailed surveys were returned too late to be incorporated into the detailed survey database.
Includes long survey respondents that discharge <1 mgy.
dDoes not include one duplicate survey received.
eNumber of respondents also includes sites with classified process information (1989 detailed survey), sites with insufficient data (1996 long survey), and surveys
returned too late to incorporate into the database (1996 long survey). The data from these surveys were not incorporated into the survey databases.
T^or the municipality survey, these numbers represent the number and percentage of POTWs receiving wastewater from facilities evaluated in the final rule, and
the number and percentage of POTWs not receiving wastewater from facilities evaluated in the final rule.
~ Not applicable to the survey.

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                                                                                                       3.0 - Data Collection Activities
          1996 Federal Detailed
           1996 POTW Detailed
       1996 Municipality Detailed
            1996 Short Detailed
     ><       1996 Long Detailed
         1996 Benefits Screener
                 1996 Screener
                 1989 Detailed
                1989 Screener
                            D Surveys Returned

                            • Respondents Engaged in MP&M
                              Operations
                             0%      10%      20%      30%     40%     50%     60%     70%      80%     90%    100%

                                                                       Percentage
NA - The number of federal surveys distributed is not certain, and the percentage of returned surveys cannot be calculated.


                           Figure 3-1.  Percentage of 1989 and 1996 MP&M Surveys Returned and
                         Percentage of Survey Respondents Performing Proposed MP&M Operations

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                                                                      3.0 - Data Collection Activities

              •      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 (MS Access 97) to store and analyze data
received from the screeners.  The database dictionary and all nonconfidential screener surveys are
located in Section 5.3.7 of the rulemaking record.

              EPA determined the number of sites engaged in proposed MP&M operations by
responses to the screener.  As shown in Table 3-1, approximately 52 percent of the 1989 screener
survey respondents reported that their sites were engaged in proposed MP&M operations and
approximately 48 percent reported no or only dry proposed MP&M operations at their sites.
EPA could not determine the status of 10 of the sites because they returned incomplete screeners
and did not respond to follow-up efforts.

              The Agency contacted a statistically representative sample of the nonrespondent
sites (i.e., sites that did not return the screener) and sites reporting "not engaged" in proposed
MP&M operations to determine whether their responses were due to confusion over the scope of
the industry.  Based on the results of this follow-up, EPA adjusted the survey weights for
misclassification and incorrect responses.  The methodology for calculating the adjustment
factors is provided in the Statistical Summary for the Metal Products & Machinery Industry
Surveys (Section 10.0, DCN 16118).

              1989 Screener Data Entry. Engineering Coding, and Analysis

              EPA reviewed all of the screener surveys prior to data entry.  As part of this effort,
the Agency reviewed all documentation provided by the site, corrected errors and deficiencies,
and coded the information for data entry.  In some cases, these revisions required telephone
contact with site personnel. The Agency contacted more than 1,100  screener recipients to resolve
survey deficiencies and code information for data entry. Following preliminary review, EPA
entered the scannable data (i.e., responses  to multiple-choice, Mark Sense™ questions) into the
database using a Scantron™ reader.  EPA scanned  each form twice and compared the
information using a computer program as a quality control check. The Agency performed double
key-entry of nonscannable data, resolved any inconsistencies, and converted the data to database
files.

              Based on the screener mailout results, EPA developed an industry profile for the
seven sectors. The screener database report provides estimates of the national population for
sites in these industrial sectors with regard to water use characteristics, size, location, sector, unit
operations, and metal types.  The Statistical Summary for the Metal  Products &  Machinery
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                                                                       3.0 - Data Collection Activities

Industry Surveys (Section 10.0, DCN 16118) discusses the sample size determination and
statistical procedures for developing national estimates for the industry.

3.1.1.2        1989 Detailed Survey

              Based on responses to the 1989 screener, EPA sent a more detailed survey to a
select group of water-using facilities performing proposed MP&M operations. This survey, also
referred to as the data collection portfolio (DCP), was designed to collect detailed technical and
financial information reflecting a site's 1989 operations.  EPA used this information to
characterize these facilities from the seven industrial sectors, develop pollutant loadings and
reductions, and develop compliance cost estimates, as discussed later in this document.

              EPA mailed 896 detailed surveys in January 1991. Based on the number of
detailed surveys returned undelivered, EPA mailed an additional 124 detailed surveys in January
and February 1991, for a total of 1,020 detailed surveys mailed.  A blank copy of the 1989
detailed survey (Section 3.7.2, DCN 17224) and copies of the nonconfidential portions of the
completed detailed surveys are located in Section 5.3.8 of the rulemaking record.

              1989 Detailed Survey Recipient Selection and Distribution

              EPA selected 1,020 sites to receive detailed surveys from the following three
groups of sites:

              •     Water-discharging 1989 screener respondents (860 sites);

              •     Water-using 1989 screener respondents that did not discharge process
                    water (74 sites); and

              •     Water-discharging sites from key companies performing proposed MP&M
                    operations that did not receive the 1989 screener (86 sites).

The methods used to select sites within each group are described below.

              The Agency mailed the 1989 detailed survey to all 860 water-discharging screener
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 these seven industrial sectors.

              The Agency mailed the 1989 detailed survey to a probability sample of 50
screener respondents that reported using but not discharging process water. EPA selected these
sites 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
facilities performing proposed MP&M operations.  In addition to the 50 probability sample sites,
EPA mailed the 1989 detailed survey to 24 screener respondents that reported using but not
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                                                                      3.0 - Data Collection Activities

discharging process water.  The Agency selected these sites because they performed unit
operations that were not expected to be sufficiently characterized by detailed surveys mailed to
other sites.  The unit operations that EPA expected at each of the 24 sites are listed in Section
3.8.2 of the rulemaking record.

              EPA mailed the 1989 detailed survey to 86 sites that did not receive the 1989
screener. The Agency identified these sites as representing key companies in the industry that
EPA did not select as 1989 detailed survey recipients based on the screener mailout. EPA
identified key companies from Dun & Bradstreet company lists, the Thomas Register, Fortune
Magazine's list of the top 500 U.S. companies, and MP&M site visits at companies with annual
revenues of $50 million or more that EPA believed to be leading companies in their particular
industrial sector.  The Agency contacted each of the key companies to identify sites within the
company that were performing proposed MP&M operations and used process water to perform
these operations.  Records of these follow-up telephone calls are located in the MP&M
rulemaking record (see Section 3.8.2). EPA did not use these 86 surveys for developing the
national estimates because the Agency did not randomly select these facilities.

              EPA operated a toll-free telephone helpline from January until July 1991 to assist
recipients in completing the 1989 detailed survey.  The helpline received approximately 1,400
calls from detailed survey recipients. Callers to the 1989 detailed survey helpline typically
requested the following:

              •     Assistance with the technical sections of the detailed survey (e.g.,
                    technical clarification of unit operation definitions);

              •     Additional time to complete the survey;

              •     Assistance with the financial sections of the detailed survey (these calls
                    were referred to a separate economics helpline); or

              •     Clarification of the applicability of the survey (i.e., did the survey apply to
                    the site?).

Records for nonconfidential telephone calls to the  helpline and to EPA personnel are located in
Section 5.3.8 of the rulemaking record.

              1989 Detailed Survey Mailout Results

              Table 3-1 summarizes the results of the detailed survey mailout. Of the 1,020
sites that received the detailed survey, 998 responded to the survey and 22 did not.  EPA did not
include 199 of the 1,020 sites that responded in the detailed survey database for one of the
following reasons:

              •     The site was out of business;
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                                                                      3.0 - Data Collection Activities

              •       The site did not use process water;

              •       The site was not performing proposed MP&M operations; or

              •       Process information at the site was Department of Defense or Department
                     of Energy classified information.

Specific reasons for not using data from these sites are documented in Section 5.3.8.2 of the
rulemaking record.

              Upon review of the detailed surveys submitted by these sites, EPA determined 87
sites to be in the other 11 industrial sectors rather than the seven sectors identified in Section
3.1.1. Because the scope of the detailed survey mailout effort included only sites from the seven
industrial sectors listed in Section 3.1.1, EPA did not include these 87 sites in the detailed survey
database.

              Information Collected

              The Agency designed the 1989 detailed survey to collect information necessary to
develop effluent limitations guidelines and standards for the MP&M rulemaking. EPA divided
the detailed survey into the following parts:

              •       Part I - General Information;
              •       Part II - Process Information;
                     Part IE - Water Supply;
              •       Part IV - Wastewater Treatment and Discharge;
              •       Part V - Process and Hazardous Wastes; and
              •       Part VI - Financial  and Economic Information.

              The detailed survey instructions and the ICR for this project contain further details
on the types of and potential uses for information collected.  These documents are located in
Section 3.7.2 of the rulemaking record, DCN 17224.

              Part I (questions 1 through 13) requested information necessary to identify the
site,  to characterize the site by certain variables, and to confirm that the site was performing
proposed 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 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. EPA requested the site to
provide detailed technical information (e.g., water balance, chemical additives, metal type
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                                                                      3.0 - Data Collection Activities

processed, disposition of wastewater) for each proposed MP&M operation and air pollution
control device using process water. This section also requested information on unique and/or
auxiliary operations.  EPA used this information to evaluate raw waste characteristics, water use
and discharge practices, and sources of pollutants for each proposed MP&M operation.

              Part in (question 22) requested information on the water supply for the site. EPA
requested the site to specify the source water origin, average intake flow, average intake
operating hours, and the percentage of water used for proposed MP&M operations.  EPA used
this information to evaluate overall water use for the site.

              Part IV (questions 23 through 33) requested detailed information on 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-monitoring data; and capital and
operating cost data.  EPA collected this information on facilities performing proposed MP&M
operations to: (1) evaluate treatment in place at these facilities; (2) develop and design a cost
model to estimate various control options; and (3) assess the long-term variability of 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.  EPA collected this information 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.  EPA collected this information to calculate the economic impacts
of the regulatory options considered for the MP&M rulemaking.

              1989 Detailed Survey Review, Coding, and Data Entry

              The Agency completed an engineering review of the detailed surveys, including
coding responses to questions from Parts I through V to facilitate entry of technical data into a
database. The MP&M DCP Database Dictionary identifying all database codes developed for
this effort and the database dictionary for Section VI of the detailed survey are located in Section
5.3.8.2 of the rulemaking record, DCN 17387.

              The Agency followed up with telephone calls to all respondents who did not
provide:  (1) information on operations (manufacturing, rebuilding, or maintenance) or sectors;
(2) metal type or unit operation descriptions for each water-using unit operation; or
(3) descriptions for each wastewater treatment operation. EPA also made follow-up calls to
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                                                                      3.0 - Data Collection Activities

clarify incomplete or contradictory technical or economic information. EPA confirmed all
information obtained from follow-up calls by sending a letter to the site.

              EPA developed a database to store all technical data provided in the detailed
surveys.  After engineering review and coding, the Agency entered data from the detailed surveys
into the database using a double key-entry and verification procedure. EPA coded and entered
data from 792 detailed survey respondents determined to be performing proposed MP&M
operations into the detailed survey database. The MP&M DCP Database Dictionary presents the
database  structure and defines each field in the detailed survey database and the codes that
describe data in these fields.

              The Economic, Environmental, and Benefits Analysis of the Proposed Metal
Products and Machinery Rule, which is located in Section 8.1 of the rulemaking record, DCN
2000, discusses EPA's review of Section VI of the detailed survey.

              1989 Detailed Survey Data Analysis

              EPA used the information collected in the detailed survey to develop an industry
profile and to identify the baseline of treatment in place and estimate the amount of pollutant
discharges from facilities performing proposed MP&M operations. Section 4.0 of this document
provides  estimates of the national population of these facilities that discharge water with regard
to size, location, sector, unit operations, metal types, and discharge flows, and discusses the
statistical procedures for developing national estimates for the industry. Section 11.0 and 12.0
present the methodologies used to estimate pollutant discharges and compliance costs,
respectively.

3.1.2          The 1996 Industry Surveys

              Between 1996 and 1998, EPA distributed one screener and five detailed surveys,
requesting data representing the survey recipients' 1996  operations.  The five detailed surveys
included  the long, short, municipality, federal, and publicly owned treatment works (POTW)
surveys. The Agency distributed the 1996 surveys to commercial and government (federal, state,
and local) facilities that manufacture, rebuild, or maintain metal products or parts to be used in
one of the following 11 industrial sectors:

              •      Bus and Truck;
              •      Household Equipment;
              •      Instruments;
              •      Job Shops;
              •      Motor Vehicles;
              •      Office Machines;
              •      Precious Metals and Jewelry;
              •      Printed Wire Boards;
              •      Railroad;
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                                                                      3.0 - Data Collection Activities

              •       Ships and Boats; and
              •       Miscellaneous Metal Products.

The 1996 screener and detailed surveys are discussed below. Recipient selection, stratification
schemes, and the type and potential use of the information requested are described in more detail
in the ICR for the 1996 screener (see Section 3.5.1, DCN 15766).

3.1.2.1        1996 Screener Survey

              In December 1996 and February 1997, EPA distributed 5,325 screener surveys to
sites believed to be engaged in manufacturing, rebuilding, or maintenance activities in one of the
11 industrial sectors listed in Section 3.1.2.  The purpose of the screener surveys was to identify
sites to receive the more detailed survey and to make a preliminary assessment of the industry for
the 11 industrial sectors.  EPA sent an additional 1,750 screeners to facilities located in Ohio (a
state with a high concentration of facilities  performing proposed MP&M operations) as part of a
benefits study. The Agency used these screeners to collect data to analyze environmental
benefits.

              1996 Screener Recipient Selection and Distribution

              As discussed above, EPA sent the 1996 screener survey to 5,325 randomly
selected facilities performing proposed MP&M operations (includes replacement sites).  The
Agency selected potential recipients from the Dun & Bradstreet database based on the industrial
sector (using the SIC code), activity (i.e., manufacturing, maintenance, or rebuilding), size as
measured by number of employees, and wastewater discharge flow rate.

              The Agency identified more than 126 SIC codes applicable to the 11 industrial
sectors. Within each sector, EPA identified between 1 and 26 SIC codes. EPA calculated the
number of sites to receive the 1996 screener within each SIC code by a coefficient of variation
(CV) minimization procedure described in the Statistical Support Document located in Section
10.0 of the rulemaking record, DCN 16119. Based on the number of sites selected within each
SIC code, the Agency obtained 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.  EPA randomly selected the initial list of sites from the Dun &
Bradstreet database for each SIC code.

              After reviewing the potential sites, EPA deleted sites for the following reasons:

              •       The site was a corporate headquarters without manufacturing, rebuilding,
                     or maintenance operations;

              •       The site received a 1989 screener or detailed survey;
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                                                                      3.0 - Data Collection Activities

              •       The site was a duplicate of another facility in the list of potential facilities
                     performing proposed MP&M operations;

              •       The site had an SIC code that was inconsistent with company name; or

              •       The site had an insufficient mailing address.

              EPA established a toll-free telephone helpline and an electronic mail address to
assist screener recipients in completing the survey. EPA received helpline calls and electronic
mail inquiries from more than 600 screener recipients. Nonconfidential notes from helpline and
review follow-up calls are located in Section 5.3.1 of the rulemaking record.

              1996 Screener Mailout Results

              EPA initially mailed 4,900 surveys in December 1996.  The Agency distributed
surveys to an additional 425 sites to replace surveys that were returned undelivered. EPA
assumed the undeliverable survey sites to be out of business. Of the 5,325 surveys mailed, 80
percent (4,248) of the recipients returned completed surveys to EPA. A blank copy of the 1996
screener (see Section 3.7.1, DCN 16367) and nonconfidential portions  of the completed screeners
are located in the public record for this rulemaking (see Section 5.3.1.1). Table 3-1 and Figure 3-
1 summarize the MP&M survey mailout results.

              The Agency contacted a statistically representative sample of nonrespondent sites
to determine whether these sites were performing proposed  MP&M operations and discharged
process wastewater. Only 24 percent of the nonrespondents contacted were performing proposed
MP&M operations, and approximately half of these facilities did not discharge process
wastewater.

              Information Collected

              The Agency requested the following site-specific information in the screener:

              •       Name and address of facility;

              •       Contact person;

              •       Whether process water is used at the  site;

              •       Destination of process wastewater discharged;

              •       Volume of process wastewater discharged;

              •       Number of employees;
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                                                                     3.0 - Data Collection Activities

              •      Annual revenue;

              •      Sectors in which the site manufactures, rebuilds, or maintains machines or
                    metal components; and

              •      Unit operations performed at the site and whether there is water use and/or
                    wastewater discharge for each unit operation performed at the site.

              The Agency used a computerized database system (MS Access 97) to store and
analyze data received from the 1996 screeners. Nonconfidential portions of the screener surveys
(see Section 5.3.1.1) and the database dictionary are located in the public record for this
rulemaking (see Section 5.3.1.2, DCN 15393).

              1996 Screener Data Review and Data Entry

              EPA reviewed the 1996 screener survey responses for accuracy and consistency
and formatted the information for data entry.  The Agency contacted approximately 1,800
screener respondents to resolve deficient and inconsistent information prior to data entry.
Following review, EPA double key entered and compared the data from the formatted screeners,
using a computer program, as a quality control check.  The Agency then reviewed the database
files for deficiencies and inconsistencies, and resolved all issues for the final survey database.

              1996 Benefits Screener Survey

              For an environmental benefits  study, EPA sent the 1996 screener survey to 1,750
(including replacement sites) randomly selected sites in Ohio, a state with a large number of
facilities performing proposed MP&M operations.  The selection criteria  and sampling frame for
the benefits screener recipients are described in more detail in memoranda located in Section
3.8.1.7 of the rulemaking record, DCN 16333.

              The Agency initially mailed the benefits screener to 1,600 facilities in October
1998. EPA mailed screeners to an additional  150 facilities in February 1999 to replace surveys
that were returned undelivered. The Agency assumed the undeliverable survey sites to be out of
business. Of the 1,750 surveys mailed, 80 percent (1,392) of the recipients returned completed
screeners to EPA. A blank copy of the 1996 benefits screener (see Section 3.7.1, DCN 16367)
and nonconfidential portions of the completed benefits  screeners (see Section 8.8.1) are located
in the public record for this rulemaking. Table 3-1 and Figure 3-1 summarize the MP&M
mailout results.

              EPA established a toll-free telephone helpline and an electronic mail address to
assist screener recipients in completing the survey. EPA received helpline calls and electronic
mail inquiries from more than 900 benefits screener recipients.  Nonconfidential notes from
helpline and review follow-up calls are located in Section 8.8.1 of the public record for this
rulemaking.
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              The Agency followed the same review, data entry, and database development
procedures used for the original 1996 screener survey. EPA contacted more than 400 screener
respondents to resolve deficient and inconsistent information prior to data entry.  The benefits
screener database is discussed in the Economic, Environmental, and Benefits Analysis of the
Proposed Metal Products and Machinery Rule.

3.1.2.2        1996 Long Detailed Survey

              EPA distributed the long detailed surveys (long survey) in June 1997 to 353
wastewater-discharging facilities performing proposed MP&M operations.  EPA designed this
survey to gather detailed technical and economic information required to develop the MP&M
effluent limitations guidelines and standards.  The long survey is discussed below.

              1996 Long Survey Recipient Selection and Distribution

              In June 1997, EPA sent the long  survey to all 353 1996 screener respondents who
indicated they performed operations in one of the 11 industry sectors listed in Section 3.1.2 and
discharged one million or more gallons of MP&M process wastewater annually. EPA established
a toll-free telephone helpline and an electronic mail address to assist long survey recipients in
completing the survey.  EPA received helpline calls and electronic mail inquiries from
approximately 200 long survey recipients. Nonconfidential notes from helpline and review
follow-up calls are located in Section 5.3.2.1 of the public record for this rulemaking.

              1996 Long Survey Mailout Results

              Of the 353 surveys mailed, 88  percent (311) of the recipients returned completed
surveys to EPA.  One survey was returned as undelivered and EPA assumed the facility to be out
of business.  A blank copy of the 1996 long survey (Section 3.7.1, DCN 713) and nonconfidential
portions of the completed long surveys are located in Section 5.3.2.1  of the  public record for this
rulemaking.  Table 3-1 and Figure 3-1 summarize the MP&M survey mailout results.

              Information Collected

              EPA divided the long detailed  survey into the following sections:

              •      Section I:     General Site Information;
              •      Section U:     General Process Information;
              •      Section HI:    Specific Process Information;
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                                                                      3.0 - Data Collection Activities

              •       Section IV:   Economic Information; and
              •       Section V:    Voluntary Supplemental Information.

Table 3-2 summarizes the information requested in the 1996 long, short, federal, and
municipality detailed surveys by question number. EPA designed these surveys to collect similar
detailed process information from different audiences, as discussed below for each survey.
Further details on the types of information collected and the potential uses of the information are
contained in the ICR for this data collection (see Section 3.5.1, DCN 15766) and in the survey
instructions that are located in Section 3.7.1 of the rulemaking record, DCN 713.

              Section I requested information to determine if the facility was performing
proposed MP&M operations. Question 1 requested the site to identify the industry sector and
type of activity (manufacturing, rebuilding, or maintenance) performed.

              Section II requested information to identify the site location and contact person,
number of employees, facility age, process wastewater discharge status and destination, and
wastewater discharge permits and permitting authority. This section also requested general
information about metal types processed, products and production levels, water use for unit
operations, and wastewater discharge from unit operations. EPA used the process information to
evaluate water use and discharge practices and sources of pollutants for each proposed MP&M
operation.

              Section HI requested detailed information on wet proposed MP&M operations,
pollution prevention practices, wastewater treatment technologies, costs for water use and
wastewater treatment systems, and wastewater/sludge disposal  costs.  EPA also requested the site
to provide block diagrams of the production process and the wastewater treatment system.  The
unit operation information requested included: metal types processed, production rate, operating
schedule, chemical additives, volume and destination of process wastewater and rinse waters, in-
process pollution prevention technologies, and in-process flow control technologies.  The
information requested for each wastewater treatment unit included: operating flow rate, design
capacity, operating time, chemical additives, and unit operations discharging to each treatment
unit. In addition, EPA requested the site to provide the type of any wastewater sampling data
collected. EPA used these data to characterize the industry, to perform subcategorization
analyses, to identify best management practices, to evaluate performance of the treatment
technology for inclusion in the regulatory options, and to develop regulatory compliance cost
estimates.

              Section IV requested detailed financial and economic information about the site or
the company owning the site. EPA collected this information to calculate the economic impacts
of the regulatory options considered for the MP&M rulemaking.

              Section V requested supplemental information on other facilities performing
proposed MP&M operations owned by the company. EPA included this voluntary section to
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measure the combined impact of proposed MP&M effluent guidelines on companies with
multiple facilities
                                    Table 3-2

     Summary of 1996 Detailed Survey Information by Question Number
Survey Question Number
Long and
Federal
Section I
1
Section II
2-5
6,7
8,9
10
—
11
12
13
Section III
14-15
16
17-23
24-29
30
31-41
42
43-44
45
—
Section IV
1-9
Section V
1
2
3
2,4
5
Short
Section I
1
Section II
2-5
6,7
8,9
10
11-12
13
15
16
—
—
—
Section II
17
—
—
—
Section II
14
—
—
Section IV
1-8
Section V
1
2
3
2,4
5
Municipality
Part II
1
2-5
5,6
7,8
9
10-11
12
13
14
—
—
—
16
—
—
—
15
—
—
Parti
1-3
—
—
—
—
—
Type of Information Requested
Industrial sector activities
Site location and facility contact
Number of employees and age of site
Discharge status and destination
Permits under miscellaneous categorical effluent guidelines
Types of end-of-pipe wastewater treatment units
Metal types processed
5 major products (quantity and sector)
Unit operations: water use and associated rinses
General water use and costs
Production process diagram
Detailed description of wet unit operations performed
In-process pollution prevention technologies or practices
Wastewater treatment (WWT) diagram
Detailed design and operating parameters of WWT units
WWT costs by treatment unit
Wastewater sampling and analysis conducted
Contract haul and disposal costs
Facility comments page
Financial and economic data
Parent firm name and contact, number of other facilities
performing proposed MP&M operations
Number of employees for other facility(ies)
Industrial and activity
Discharge status and destination
Unit operations: water use and discharge status
— Question is not applicable to this survey.
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performing proposed MP&M operations that discharge process wastewater. This section
requested the same information collected in the 1996 MP&M screener survey.  Responses to
questions in this section provided the size, industrial sector, revenue, unit operations, and water
usage of the company's other facilities performing proposed MP&M operations.

              1996 Long Survey Data Review and Data Entry

              EPA completed a detailed engineering review of Sections I through in of the
detailed long  survey to evaluate the accuracy of technical information provided by the
respondents.  During the engineering review, EPA coded responses to facilitate entry of technical
data into the long survey database.  The MP&M 1996 Long Survey Database Dictionary
identifies the  database codes developed for this project, and is located in Section 5.3.2.2 of the
rulemaking record, DCN 15773. EPA contacted approximately 240 long survey respondents, by
telephone and letter, to clarify incomplete or inconsistent technical information prior to data
entry.

              The Agency developed a database for the technical information  provided by
survey respondents. After engineering review and coding, EPA entered data from 303 long
surveys into the database using a double key-entry and verification procedure.  The MP&M  1996
Long Survey Database Dictionary presents the database structure and defines each field in the
database files. EPA did not include data from 8 long survey respondents in the database for the
following reasons:

              •      The site was  out of business;

              •      The site did not use process water;

              •      The site was  not performing proposed MP&M operations; or

              •      The site provided insufficient data and the survey was returned too late to
                    enter into the database.

              The Economic, Environmental, and Benefits Analysis of the Proposed Metal
Products and  Machinery Rule, which is located in Section 8.1  of the rulemaking record, DCN
2000, discusses EPA's review of Section IV of the detailed survey.

3.1.2.3        1996 Short Detailed Survey

              EPA distributed the short detailed survey (short survey) in September 1997 to 101
wastewater-discharging facilities performing proposed MP&M operations.  EPA designed this
survey to gather additional technical and economic information required to develop the MP&M
effluent limitations guidelines and standards.  The short survey is discussed below.
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              1996 Short Survey Recipient Selection and Distribution

              EPA initially sent 100 short surveys in September 1997 and mailed one additional
survey to a site to replace a  short survey that was returned undelivered.  EPA assumed the
undeliverable site to be out  of business. The Agency sent the short surveys to randomly selected
1996 screener respondents who performed operations in one of the 11 industry sectors identified
in Section 3.1.2 and indicated they discharged less than one million gallons of MP&M process
wastewater annually. The selection criteria and sampling frame for short survey recipients are
described in more detail in the Statistical Summary for the Metal Products & Machinery Industry
Surveys (Section 10.0, DCN 16118).

              EPA established a toll-free telephone helpline and an electronic mail address to
assist short survey recipients in completing the survey. EPA received helpline calls and
electronic mail inquiries from approximately 20 short survey recipients. Nonconfidential notes
from helpline and review follow-up calls are located in Section 5.3.3.1 of the public record for
this rulemaking.

              1996 Short Survey Mailout Results

              Of the 101 surveys mailed, 82 percent (83 surveys) of the recipients returned
completed surveys to EPA.  A blank copy of the 1996 short survey (Section 3.7.1, DCN 16368)
and nonconfidential portions of the completed short surveys (Section 5.3.3.1) are located in the
public record for this rulemaking. Table 3-1 and Figure 3-1 summarize the MP&M survey
mailout results.

              Information Collected

              The information collected in the 1996 short survey included the identical general
site and process information and economic information collected in Sections I, n, IV, and V of
the long detailed survey (see Section 3.1.2.2). To minimize the burden on facilities discharging
less than one million gallons of process wastewater, EPA did not require these facilities to
provide the detailed information on proposed MP&M operations or treatment technologies that
EPA requested in Section HI of the long survey. The ICR for this data collection and the survey
instructions contain further  details on the types of information collected and the potential uses of
the information.

              EPA divided the short survey into the following sections:

              •       Section I:     General Site Information;
              •       Section II:    General Process Information;
              •       Section IV:   Economic Information; and
              •       Section V:    Voluntary Supplemental Information.
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Section HI, Specific Process Information, consisted of a statement that EPA was not requesting
this information to reduce burden on sites discharging less than one million gallons of process
wastewater per year.  Table 3-2 summarizes the 1996 short survey information by question
number.

              1996 Short Survey Data Review and Data Entry

              EPA completed a detailed engineering review of Sections I and II of the short
survey to evaluate the accuracy of technical information provided by the respondents. During the
engineering review, EPA coded responses to facilitate entry of technical data into the short
survey database.  The MP&M 1996 Short Survey Database Dictionary identifies the database
codes developed for this project and is located in Section 5.3.3.2 of the rulemaking record, DCN
15772. EPA contacted more than 60 short survey respondents, by telephone and letter, to clarify
incomplete or inconsistent technical information prior to data entry.

              The Agency developed a database for the technical information provided by
survey respondents. After engineering review and coding, EPA entered data for 75 short surveys
into the database using a double key-entry and verification procedure.  The MP&M 1996 Short
Survey Database Dictionary presents the database structure and defines each field in the database
files.  EPA did not include data from eight short survey respondents in the database for the
following reasons:

              •      The site was  out of business;
              •      The site did not use process water; or
              •      The site was  not performing proposed MP&M operations.

              The Economic, Environmental, and Benefits Analysis of the Proposed Metal
Products and Machinery Rule, which is located in Section 8.1 of the rulemaking record, DCN
2000, discusses EPA's review of Section IV of the short survey.

3.1.2.4        1996 Municipality Detailed Survey

              EPA distributed the municipality surveys in June 1997 to 150 city and county
facilities that might operate facilities performing proposed MP&M operations. EPA designed
this survey to measure the impact of this rule on municipalities and other government entities
that perform certain maintenance and rebuilding operations (e.g., bus and truck, automobiles).

              Recipient Selection and Distribution

              The Agency sent the municipality survey to 150 city and county facilities
randomly selected from the Municipality Year Book-1995 based on population and geographic
location. EPA allocated 60 percent of the sample to municipalities and 40 percent to counties.
The 60/40 distribution was approximately proportional to their aggregate populations in the
frame. The Agency divided the municipality sample and the county sample into three size
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groupings as measured by population.  For municipalities, the population groupings were: less
than 10,000 residents, 10,000 - 50,000 residents, and 50,000 or more residents. For counties, the
population groupings were: less than 50,000 residents, 50,000 - 150,000 residents, and 150,000
or more residents.  The geographic stratification conformed to the Census definitions of
Northeast, North Central, South, Pacific, and Mountain states.

              EPA established a toll-free telephone helpline and an electronic mail address to
assist municipality survey recipients in completing the survey.  EPA received helpline calls and
electronic mail inquiries from more than 50 municipality survey recipients.  Notes from helpline
and review follow-up calls are located in Section 5.3.4.1 of the rulemaking record.

              1996 Municipality  Survey Mailout Results

              Of the 150 municipality surveys mailed, three surveys were returned undelivered
and 135 surveys (90 percent) of the recipients returned completed surveys to EPA. A blank copy
of the 1996 municipality survey (Section 3.7.1, DCN 16366) and nonconfidential portions of the
completed municipality surveys (Section 5.3.4.1) are located in the public record for this
rulemaking. Table 3-1 and Figure 3-1  summarize the MP&M survey mailout results.

              Information Collected

              The 1996 municipality survey collected economic information for the entire
municipality and site-specific process information for each facility performing proposed MP&M
operations operated by the municipality.

              EPA divided the municipality detailed survey into the following parts:

              •       Part I: Economic and Financial Information; and
              •       Part II: General Site-Specific Process Information.

Table 3-2 summarizes the 1996 municipality survey information by question number. The ICR
for this data collection (Section 3.5.1, DCN 15766) and the survey instructions (Section 3.7.1,
DCN 15366) contain further details on the types of information collected and the potential uses
of the information and are located in the rulemaking record.

              Part I requested information on the site location and contact person, number of
employees, detailed financial and  economic information about the entire municipality, and
information necessary to determine if the municipality owned and operated facilities performing
proposed MP&M operations in any of the proposed industrial sectors.

              Part II requested site-specific process information for each facility performing
proposed MP&M operations owned and operated by the municipality.  Question 1  requested the
site to identify the industry sector  and type of activity (manufacturing, rebuilding, or
maintenance) performed. The remaining questions were identical to Section II of the short
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detailed survey and requested facility age, process wastewater discharge status and destination,
wastewater discharge permits and permitting authority, general information about metal types
processed, products and production levels, water use for unit operations, and wastewater
discharge from unit operations. The Agency used the process information to evaluate water use
and discharge practices and sources of pollutants for each proposed MP&M operation.

              1996 Municipality Survey Data Review and Data Entry

              EPA completed a detailed engineering review of Part n of the municipality survey
to evaluate the accuracy of technical information provided by the respondents. During the
engineering review, the Agency coded responses to facilitate entry of technical data into the
municipality survey database. The MP&M 1996 Municipality Survey Database Dictionary
identifies the database codes developed for this project, and is located in Section 5.3.4.2 of the
rulemaking record, DCN 15771. EPA contacted more than  50 municipality survey respondents
by telephone to clarify incomplete or inconsistent technical information prior to data entry.

              The Agency developed a database for the technical information provided by
survey respondents. After engineering review and coding, EPA entered data from 209
municipality facilities into the database using a double key-entry and verification procedure.
This number is greater than the number of respondents because some municipalities had more
than one facility performing proposed MP&M operations. The MP&M 1996 Municipality
Survey Database Dictionary presents the database structure and defines each field  in the database
files.

              The Economic, Environmental, and Benefits Analysis of the Proposed Metal
Products and Machinery Rule, which is located in Section 8.1 of the rulemaking record, DCN
2000, discusses EPA's review of Part I of the municipality survey.

3.1.2.5        1996 Federal Facilities Detailed Survey

              In April 1998, EPA distributed the federal facilities detailed survey (federal
survey) to the following seven federal agencies:

              •      Department of Energy;
              •      Department of Defense;
              •      National Aeronautics and Space Administration (NASA);
              •      Department of Transportation (including the United States Coast Guard);
              •      Department of Interior;
              •      Department of Agriculture; and
              •      United States Postal Service.

EPA used this survey to assess the impact of the MP&M effluent limitations guidelines and
standards on federal agencies that operate facilities performing proposed MP&M operations.
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                                                                      3.0 - Data Collection Activities

              Recipient Selection and Distribution

              There was no specific sampling frame for the federal survey. EPA distributed the
survey to federal agencies likely to perform industrial operations on metal products or machinery.
 EPA requested representatives of seven federal agencies to voluntarily distribute copies of the
survey to sites they believed performed proposed MP&M operations. The selection criteria for
federal survey recipients are described in more detail in the ICR for the 1996 MP&M industry
surveys. Because the sample was not randomly selected, EPA did not use data from  these
surveys to develop national estimates.

              EPA established a toll-free telephone helpline and an electronic mail address to
assist federal survey recipients in completing the survey. EPA received helpline calls and
electronic mail inquiries from approximately 20 federal survey recipients. Nonconfidential notes
from helpline and review follow-up calls are located in Section 5.3.5.1 of the public record for
this rulemaking.

              1996 Federal Survey Distribution Results

              The Agency received 51 completed federal  surveys, 39 from Department of
Defense facilities and 12 from NASA facilities.  A blank copy of the 1996 federal survey
(Section 3.7.1, DCN 721) and nonconfidential portions of the completed federal surveys are
located in Section 5.3.5.1 of the public record for this rulemaking.

              Information Collected

              The information requested in Sections I and in of the 1996 federal survey was
identical to the long survey (see Section 3.1.2.2).  The financial and economic questions in
Section IV were revised to obtain this information for only the MP&M activities on a federal site.
The ICR for this data collection and the survey instructions contain further details on the types of
information collected and the potential uses of the information.  Table 3-2 summarizes the 1996
federal detailed survey information by question number.

              Data Review and Data Entry

              EPA completed a detailed engineering review of Sections I through in of the
federal survey to evaluate the accuracy of technical information provided by the respondents.
During the engineering review, the Agency coded responses  to facilitate entry of technical data
into the federal survey database.  The MP&M 1996 Federal Survey Database Dictionary
identifies the database codes developed for this project and is located in Section 5.3.5.2 of the
rulemaking record, DCN 15991.

              The Agency developed a database for the technical information provided by
survey respondents.  After engineering review and coding, EPA entered data from 44 federal
surveys into the database using a double key-entry and verification procedure. The Agency did
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not include data from seven federal survey responses in the database because the sites did not use
MP&M process water. The MP&M 1996 Federal Survey Database Dictionary presents the
database structure and defines each field in the database files.

              The Economic, Environmental, and Benefits Analysis of the Proposed Metal
Products and Machinery Rule, which is located in Section  8.1 of the rulemaking record, DCN
2000, discusses EPA's review of Section IV of the federal  survey.

3.1.2.6        1996 POTW Detailed Survey

              EPA  distributed the POTW survey to 150 sites in November  1997. The Agency
designed this survey to evaluate benefits associated with the MP&M regulations and to estimate
possible costs and burden that POTWs might incur in writing and maintaining MP&M permits or
other control mechanisms.

              Recipient Selection and Distribution

              The Agency sent the POTW survey to 150 POTWs with flow rates greater than
0.50 million gallons per day.  EPA randomly selected the recipients from the 1992 Needs Survey
Review, Update, and Query System Database. EPA divided the POTW sample into two strata by
daily flow rates: 0.50 to 2.50 million gallons, and 2.50 million gallons or more.  The selection
criteria and sampling frame for POTW survey recipients are described in more detail in the ICR
for the 1996 surveys.

              EPA  established a toll-free telephone helpline and an electronic mail address to
assist POTW survey recipients in completing the survey. EPA received helpline calls and
electronic mail inquiries from approximately 50 POTW survey respondents. Nonconfidential
notes from helpline and review follow-up calls are located in Section 8.7 of the public record for
this rulemaking.

              1996 POTW Survey Mailout Results

              Of the 150 POTW surveys mailed, two surveys were returned undelivered and 98
percent (147) of the  recipients returned completed surveys to EPA. A blank copy of the  1996
POTW survey  (Section 3.7.1, DCN 16369) and nonconfidential portions  of the completed
POTW survey  (Section 8.7) are located in the public record for this rulemaking.  Table 3-1 and
Figure 3-1 summarize the MP&M survey mailout results.

              Information Collected

              The POTW  survey requested data required to estimate benefits and costs
associated with implementation of the MP&M regulations. The ICR for this data collection and
the survey instructions contain further details on the types  of information collected and the
potential uses of the information. EPA divided the POTW survey into the following parts:
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                                                                     3.0 - Data Collection Activities

              •      Part I: Introduction and Basic Information;
              •      Part II: Administrative Permitting Costs; and
              •      Part IE: Sewage Sludge Use or Disposal Costs.

              Part I requested site location and contact information and the total volume of
wastewater treated at the site. EPA used the wastewater flow information to characterize the size
ofthePOTW.

              Part II requested the  number of industrial permits written, the cost to write the
permits, the permitting fee structure, the percentage of industrial dischargers covered by National
Categorical Standards (i.e., effluent guidelines), and the percentage of permits requiring
expensive administrative activities.  EPA used this information to estimate administrative burden
and costs.

              Part in requested information on the use or disposal of sewage sludge generated
by the POTW. EPA required only POTWs that received discharges from facilities performing
proposed MP&M operations to complete Part IE.  The sewage sludge information requested
included the amount generated, use or disposal method, metal  levels, use or disposal costs, and
the percentage of total metal loadings at the POTW from facilities  performing proposed MP&M
operations. The Agency used this information to assess the potential changes in sludge handling
resulting from the MP&M rule and  to estimate economic benefits to the POTW related to sludge
disposal and reduction in upsets/interference.

              Data Review and Data Entry

              EPA performed a detailed review of the POTW survey to evaluate the accuracy of
information provided by the respondents. During the review, the Agency coded responses to
facilitate entry of data into the POTW survey database. The database dictionary for the POTW
survey identifies the database codes developed for this project, and is located in Section 8.7 of
the rulemaking record.  EPA contacted more than 95 POTW survey respondents by telephone to
clarify incomplete or inconsistent information prior to data entry.

              The Agency developed a database for the information provided by survey
respondents.  After review and coding, EPA entered data from 147 POTW surveys into the
database using a double key-entry and verification procedure.  The database dictionary presents
the database structure and defines each field in the database files.

3.1.3          1997 Iron  and Steel Industry Survey Data

              As part of its effort to review and revise effluent limitations guidelines and
standards for the Iron and Steel Point Source Category (40  CFR 420), EPA distributed, reviewed,
and coded the iron and steel industry detailed and short surveys of  402 iron and steel facilities in
November 1998.
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                                                                      3.0 - Data Collection Activities

              EPA included data from 154 iron and steel surveys in the MP&M survey database.
EPA used these 154 Iron & Steel surveys to create a new subcategory, Steel Forming and
Finishing, in the January 2001 proposal. Based on comments to the January 2001 proposal and
June 2002 NOD A, EPA concluded that those operations included in the proposed Steel Forming
and Finishing Subcategory of the MP&M Point Source Category should remain subject to the
effluent guidelines and standards at the Iron and Steel Point Source Category (40 CFR 420). See
Section 6.0 for further discussion of subcategorization.

              As discussed in the June 2002 NODA (67 FR 38752), EPA considered
establishing a segment of the Steel  Forming and Finishing Subcategory for discharges resulting
from continuous electroplating of flat steel products (e.g., strip, sheet, and plate).  EPA examined
its database for facilities that perform continuous steel electroplating and found that continuous
electroplaters do not perform operations similar to facilities in the proposed Steel Forming and
Finishing Subcategory. Rather, continuous electroplaters perform operations included in the
proposed General Metals Subcategory.  Therefore, in evaluating options for the final rule, EPA
included continuous electroplaters in the proposed General Metals Subcategory. See Section 6.0
for a detailed discussion of subcategorization. For this reason, EPA incorporated the information
on these operations reported in 24 iron and steel surveys into the MP&M database.  Operations
on the continuous electroplating lines may include:

              •       Acid cleaning;
              •       Alkaline cleaning;
              •       Conversion coating (e.g., passivation, surface activation/fluxing);
              •       Electroplating;
              •       Rinsing; and
              •       Sealing.

              All 24 sites with electroplating lines processing steel flat-rolled products
discharge process wastewater.  The Agency coded and entered process and wastewater treatment
information from  the 47 lines in the 24 iron and steel surveys into the MP&M cost model. A
blank copy of the  1997 iron and steel detailed and short surveys and nonconfidential portions of
the 24 completed  iron and steel  surveys are located in Sections 5.3.6 and 15.1  of the public
record for this rulemaking. As discussed in Section 9.0, EPA rejected establishing limitations and
standards for the proposed General Metals Subcategory. Continuous electroplaters remain subject
to the Metal Finishing Point Source Category (40 CFR 433), as applicable.

              1997 Iron and Steel  Survey Recipient Selection and Distribution

              The Agency consulted with industry trade associations and visited a number of
sites to develop the survey instruments and to ensure an accurate mailing list.
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                                                                       3.0 - Data Collection Activities

              EPA distributed four industry surveys:

                     U.S. EPA Collection of 1997 Iron and Steel Industry Data (detailed
                     survey);

                     U.S. EPA Collection of 1997 Iron and Steel Industry Data (Short Form)
                     (short survey);

              •      U.S. EPA Collection of Iron and Steel Industry Wastewater Treatment
                     Capital Cost Data (cost survey); and

              •      U.S. EPA Analytical and Production Data Follow-Up to the Collection of
                     1997 Iron and Steel Industry Data (analytical and production survey).

              In October 1998, EPA mailed the detailed survey to 176 iron and steel sites and
the short survey to 223 iron and steel sites.  EPA designed the detailed survey for those iron and
steel sites that perform any iron and steel manufacturing process. Those sites include integrated
and non-integrated steel mills, as well as sites that were initially identified as stand-alone
cokemaking plants, stand-alone sinter plants, stand-alone direct-reduced ironmaking plants,
stand-alone hot forming mills, and stand-alone finishing mills. The short survey is an
abbreviated version of the detailed survey.  It was designed for stand-alone iron and steel sites
with the exceptions of those that received the detailed survey. EPA mailed the cost survey and
the analytical and production survey to subsets of the facilities that received the detailed or short
survey to obtain more detailed information on wastewater treatment system costs, analytical data,
and facility production.  EPA mailed the cost survey to 90 iron and steel sites and the analytical
and production survey to 38 iron and steel sites.

              EPA mailed the iron and steel industry surveys by mail to facilities that were
identified from the following sources:

              •      Association of Iron and Steel Engineers' 1997 and 1998 Directories: Iron
                     and Steel Plants Volume 1, Plants and Facilities;

              •      Iron and Steel Works of the World (11th and 12th editions) directories;

              •      Iron and Steel Society's The Steel Industry of Canada, Mexico, and the
                     United States: Plant Locations;

              •      Member lists from the following trade associations:
                            American Coke and Coal Chemicals Institute,
                            American Galvanizers Association,
                            American Iron and Steel Institute,
                            American Wire Producers Association,
                            Cold Finished Steel Bar Institute,
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                                                                      3.0 - Data Collection Activities

                            Specialty Steel Industry of North America,
                            Steel Manufacturers Association,
                            Steel Tube Institute of North America, and
                            Wire Association International;

              •      Dun & Bradstreet Facility Index Database:

              •      EPA's Permit Compliance System (PCS) Database:

              •      EPA's Toxic Release Inventory (TRI) Database:

              •      Iron and Steel Society's Iron and Steelmaker "Roundup" editions;

              •      33 Metalproducing "Roundup" editions (Reference 3-22);

              •      33 Metalproducing "Census of the North American Steel Industry"; and

              •      Thomas Register.

              The Agency cross-referenced these sources with one another to develop a list of
individual sites. Based on these sources, EPA identified 822 candidate facilities to receive
surveys.  To minimize the burden on the respondents, EPA grouped facilities into 12 strata. In
general, EPA determined the strata based on its understanding of the manufacturing processes at
each facility.

              Depending on the amount or type of information EPA required for the
rulemaking, EPA either solicited information from all facilities within a stratum (i.e., a census or
"certainty" stratum) or selected a random sample of facilities within a stratum (i.e., statistically
sampled stratum). EPA sent a survey to all facilities in the certainty strata (strata 5 and 8)
because the Agency determined it was necessary to capture the size, complexity, or uniqueness of
the steel operations at these sites.  EPA also sent surveys to all facilities in strata 1 through 4 (all
cokemaking sites, integrated steelmaking sites, and sintering and direct-reduced ironmaking
sites) because of the relatively low number of sites in each stratum and because of the size,
complexity, and uniqueness of raw material preparation and steel manufacturing operations at
these sites. The Agency statistically sampled the remaining sites in strata 6, 7, and 9 through 12.
EPA calculated survey weights for each selected facility based on the facility's probability of
selection.  If the Agency sent a survey to every facility in a stratum, each selected facility
represents only itself and has a survey weight of one.  For statistically sampled strata, each
selected facility represents itself and other  facilities within that stratum that were not selected to
receive an industry survey. These facilities have survey weights greater than one. See the
Development Document for Final Effluent Limitations Guidelines and Standards for the Iron and
Steel Manufacturing Point Source Category (EPA-821-R-02-004) for more details.
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                                                                        3.0 - Data Collection Activities

              Of the 822 candidate facilities, EPA mailed either a detailed survey or a short
survey to 399 facilities.2 Detailed survey recipients included integrated mills, non-integrated
mills, stand-alone cokemaking sites, stand-alone sintering sites, stand-alone direct-reduced
ironmaking sites, stand-alone hot forming sites, and stand-alone finishing sites.  Short survey
recipients included stand-alone cold forming sites, stand-alone pipe and tube sites, stand-alone
hot dip coating sites, and stand-alone wire sites.

              Once the Agency completed a review of the detailed and short surveys and
defined the technology options, EPA identified survey respondents who had installed wastewater
treatment systems in the last 10 years (since 1990) that were similar to the technology options
and mailed them the cost survey.  EPA selected 38 facilities to receive the analytical and
production survey who had indicated in the detailed or short survey that:  (1) they had treatment
trains similar to the treatment technology options, (2) they had collected analytical data for that
treatment train, (3) they had a treatment train with a dedicated outfall from which EPA could
evaluate performance, and (4) they did not add excessive dilution water to the outfall before
sampling.

              1997 Iron and Steel Survey Information Collected

              The detailed and short surveys were divided into two parts: Part A:  Technical
Information and Part B: Financial and Economic Information. The "Part A" technical questions
in the detailed survey comprised four sections, with Sections 3 and 4 being combined in the short
survey, as follows:

              •      Section 1:  General Site Information;

              •      Section 2:  Manufacturing Process Information;

              •      Section 3:  In-Process and End-of-Pipe Wastewater Treatment and
                     Pollution Prevention Information; and

              •      Section 4:  Wastewater Outfall Information.

              The financial and economic information in Part B of the detailed survey also
comprised four sections, as shown below:

              •      Section 1:  Site Identification;
              •      Section 2:  Site Financial Information;
              •      Section 3:  Business Entity Financial Information; and
2Before the surveys were actually mailed, the Agency notified potential survey recipients. One site, randomly
selected from stratum 12 and notified that it would be receiving a survey, notified the Agency that it was not engaged
in iron and steel activities.  The Agency decided not to mail a survey to that site. Therefore, this site was not
included in the 399 facilities receiving surveys.

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                                                                      3.0 - Data Collection Activities

              •       Section 4: Corporate Parent Financial Information.

              Part B of the short survey contained a single section for site identification and
financial information. More detailed descriptions of financial data collection and analysis are
included in the Economic Analysis of Final Effluent Limitations Guidelines and Standards for
the Iron and Steel Manufacturing Point Source Category (EPA 821-R-02-006).

              The detailed survey requested detailed descriptions of all manufacturing processes
and treatment systems on site.  The short survey contained manufacturing process questions for
only forming and finishing operations. EPA eliminated the cokemaking, ironmaking, and
steelmaking questions from the short survey because those processes were not applicable to the
facilities that received the short survey. The Agency also reduced the amount of detail requested
in the short survey.  EPA used the detailed descriptions of hot forming mills from the integrated,
non-integrated, and stand-alone hot forming mills to make assumptions about industry trends.

              Part A Section 1 requested site contacts and addresses and general information
regarding manufacturing operations, age, and location.  The  Agency used this information to
develop the proposed subcategorization and applicability statements.

              Part A Section 2 requested information on products, types of steel produced,
production levels, unit operations, chemicals and coatings used, quantity of wastewater
discharged from unit operations, miscellaneous wastewater sources, flow rates, pollution
prevention activities, and air pollution control. The Agency used these data to evaluate
manufacturing processes and wastewater generation, to develop the model production-
normalized flow rates, and to develop regulatory options. EPA also used these data to develop
the proposed subcategorization and applicability and to estimate compliance costs and pollutant
removals associated with the regulatory options EPA considered for the final rule.

              Part A Section 3 requested detailed information (including diagrams) on the
wastewater treatment systems and discharge flow rates, monitoring analytical data, and operating
and maintenance cost data (including treatment chemical usage).  The Agency used these data to
identify treatment technologies in place, to determine regulatory options, and to estimate
compliance costs and pollutant removals associated with the regulatory options considered for
the final rule.

              Part A Section 4 requested permit information, discharge locations, wastewater
sources to each outfall, flow rates, regulated pollutants and limits, and permit monitoring data.
EPA used this information to calculate baseline or current loadings for each facility. The Agency
also used this information to calculate the pollutant loadings associated with the regulatory
options considered for the final rule.

              The cost survey requested detailed capital cost data on selected wastewater
treatment systems installed since 1993, including equipment, engineering design, and installation
costs.  (EPA chose 1993 because 1997 was the base year for the detailed and short surveys, and
                                           3-31

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                                                                      3.0 - Data Collection Activities

this provided the Agency with a five-year range for collecting cost data on recently installed
treatment systems.) EPA incorporated these data into a costing methodology and used them to
determine incremental investment costs and incremental operating and maintenance costs
associated with the regulatory options considered for the final rule.

              The analytical and production survey requested detailed daily analytical and flow
rate data for selected sampling points, and monthly production data and operating hours for
selected manufacturing operations. The Agency used the analytical data collected to estimate
baseline pollutant loadings and pollutant removals from facilities with treatment in place similar
to the technology options considered for the final rule, to evaluate the variability associated with
iron and  steel industry discharges, and to establish effluent limitations guidelines and standards.
The Agency used the production data collected to evaluate the production basis for applying the
proposal in National Pollutant Discharge Elimination System (NPDES) permits and pretreatment
control mechanisms.

              1997 Iron and Steel Surveys Data Review and Data Entry

              EPA completed a detailed engineering review of the detailed surveys to evaluate
the accuracy of technical information provided by the respondents.  During the engineering
review, EPA coded responses to facilitate entry of technical data into the survey  database.  EPA
contacted survey respondents, by telephone and letter, to clarify incomplete or inconsistent
technical information prior to data entry.

              The Agency developed a database for the technical information provided by
survey respondents. After engineering review and coding, EPA entered data from the surveys
into the database using a double key-entry and verification procedure. During the engineering
review, EPA coded responses to facilitate entry of technical data into the survey  database.

3.1.4          Data Submitted by the American Association of Railroads (AAR)

              As noted in the June 2002 NOD A (67 FR 38752), EPA conducted another review
of all railroad line maintenance (RRLM) facilities in the MP&M questionnaire database to
determine the destination of discharged wastewater (i.e., either directly to surface waters or
indirectly to POTWs or both) and the applicability of the final rule to discharged wastewaters.
As a result of this review, EPA determined its questionnaire  database did not accurately represent
direct dischargers in this subcategory. Consequently, EPA used information supplied during the
comment period by the American Association of Railroads (AAR) as a basis for  its analyses and
conclusions on direct dischargers in this subcategory.

              AAR is a trade association which currently represents all facilities in the RRLM
Subcategory. As discussed in the NODA (see 67 FR 38755), for each RRLM direct discharging
facility known to them, AAR provided current permit limits, treatment-in-place,  and summarized
information on each facility's measured monthly average and daily maximum values.  AAR also
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                                                                     3.0 - Data Collection Activities

provided a year's worth of long-term monitoring data for each facility (see Section 15.1 of the
rulemaking record for the AAR surveys).

              AAR provided information on 27 facilities. EPA reviewed the information on
each of these facilities to ensure they were direct dischargers, discharged wastewaters resulting
from operations subject to this final rule, and discharged "process" wastewaters as defined by the
final rule. As a result of this review, EPA concluded 18 of the facilities for which AAR provided
information do not directly discharge wastewaters exclusively from oily operations.  Therefore,
EPA's final database consists of nine direct discharging RRLM facilities.

3.1.5          National Estimates

              EPA used the data collected in the MP&M and iron and steel industry surveys to:
(1) calculate national estimates of the number and types of facilities performing proposed
MP&M operations; (2) develop the industry profile presented in Section 4.0; (3) estimate the
current pollutant discharges from facilities performing proposed MP&M operations; and (4)
identify the baseline of treatment in place. The Agency assigned each survey a specific survey
weight to use as a multiplier for national estimates.

              Sampling Frame

              To produce a mailing list of facilities for the MP&M and the iron and steel
surveys, EPA developed a sampling frame of the industry. A sampling frame is a list of all
members (sampling units) of a population, from which a random sample of members will be
drawn for the survey. Therefore,  a sample frame is the basis for the development of a sampling
plan to select a random  sample. A sample frame size (N) is the total number of members in the
frame.

              EPA mailed MP&M industry surveys to all of the facilities in the sample. Based
on the survey responses, EPA determined that some facilities were "out of scope" or "ineligible"
because the regulation would not apply to them.  EPA also made a nonrespondent adjustment to
the weights (see below).

              Calculation of Sample Weights

              The next step in developing national estimates is to calculate the base weights,
nonresponse adjustments, and the final weights.  The base weights and nonresponse adjustments
reflect the probability of selection for each facility and adjustments for facility-level
nonresponses,  respectively.  Weighting the data allows inferences to be made about all eligible
facilities, not just those included in the sample, but also those not included in the sample or those
that did not respond to the survey. Also, the weighted estimates have a smaller variance than
unweighted estimates. In its analysis, EPA applied sample weights to survey data.
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                                                                     3.0 - Data Collection Activities

              Calculation of National Estimates

              For each characteristic of interest (e.g., number of sites using a particular unit
operation or annual discharge flow from a particular unit operation), EPA estimated totals for the
entire U.S. industry performing proposed MP&M operations (i.e., national estimates).  Each
national estimate, Yst, was calculated as:
                                T                  nh
                        Yst =   E   [FINALWT,  •  E   yhi]                       (3-1)
                              h=l                i=l

where:
              h            =      Survey where h = 1,2, ... T;
              T            =      Total number of surveys;
              FINALWTh  =      Final weight for survey h; and
              yw           =      ith value from the sample.

The development of survey weights and national estimates for the MP&M surveys are discussed
in greater detail in the Statistical Summary for the Metal Products & Machinery Industry Surveys
(Section  10.0, DCN 16118) andDCNs 36086 and 36087,  Section 19.5.

              Each national estimate for the entire U.S. iron and steel industry, Yst, was
calculated as:
                                       12                  nh
                               tst  =   E   [FINALWT, •  E   yhi]                 (3-2)
                                     h=l                i=l

where:

              h            =      Stratum and h=l,2,... 12 since there are 12 strata;
              FINALWTh  =      Final weight for the stratum h; and
              yih           =      Ith value from the sample in stratum h.

The development of the iron and steel survey weights and national estimates are discussed in
greater detail in the Development Document for Final Effluent Limitations  Guidelines and
Standards for the Iron and Steel Manufacturing Point Source Category (EPA-821-R-02-004).

3.2           Site Visits

              The Agency visited 234 facilities performing proposed MP&M operations and
iron and  steel sites between 1986 and 2001 to collect information about proposed MP&M
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 3.3). In general, the Agency visited sites to encompass the range of sectors,
unit operations, and wastewater treatment technologies within the industry (discussed in Section


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                                                                       3.0 - Data Collection Activities

3.2.1). Table 3-3 lists the number of sites visited within each industrial sector. The total number
of site visits presented in this table exceeds 234 because some sites had operations in more than
one sector. Figure 3-2 presents the number of facilities visited and sampled by industrial sector.
Table 3-3 and Figure 3-2 also include site visits initially conducted as part of the iron and steel
rulemaking, the results of which were incorporated into the MP&M rulemaking.

                                       Table 3-3

        Number of Sites Visited Within Each  Proposed Industrial Sector
Industrial Sectors
Aerospace
Aircraft
Bus and Truck
Electronic Equipment
Hardware
Household Equipment
Instrument
Job Shops
Miscellaneous Metal Products
Mobile Industrial Equipment
Motor Vehicle
Total
Number of
Sites Visited
13
32
8
23
15
4
4
25
0
7
20
Industrial Sectors
Office Machines
Ordnance
Precious Metals and Jewelry
Printed Wiring Boards
Railroad
Ships and Boats
Stationary Industrial Equipment
Steel Continuous Electroplating'
Steel Forming and Finishing: Wire
Drawing1

Total
Number of
Sites Visited
5
15
2
17
10
7
14
15
4


Source: MP&M and Iron and Steel Site Visits.
"The number of sites visited is listed separately for steel forming and finishing and steel continuous electroplating
sites instead of by industrial sector.
3.2.1
Criteria for Site Selection
              The Agency selected sites for visits based on information contained in the MP&M
and iron and steel surveys.  The Agency also contacted regional EPA personnel, state
environmental agency
                                           3-35

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                                                                                                                          3.0 - Data Collection Activities
     Steel Forming and Finishing - Wire Draw ing
              Steel Continuous Electroplating
              Stationary Industrial Equipment
                          Ships and Boats
                                Railroad
                      Printed Wiring Boards
                Precious Metals and Jewelry
                               Ordnance
                          Office Machines
                          Motor Vehicles
                  Mobile Industrial Equipment
               Miscellaneous Metal Products
                   Job Shop Metal Finishing
                              Instruments
                      Household Equipment
                               Hardw are
                      Electronic Equipment
                           Bus and Truck
                                Aircraft
                              Aerospace
                                                                                 15           20
                                                                                 Number of Sites
Figure 3-2. Number of Facilities Performing Proposed MP&M Operations Visited and Sampled by Industrial Sector

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                                                                       3.0 - Data Collection Activities

personnel, and local pretreatment coordinators to identify facilities performing proposed MP&M
operations believed to be operating in-process source reduction and recycling technologies and/or
well-operated end-of-pipe wastewater treatment technologies. For visits to iron and steel sites
prior to receipt of any completed survey, EPA used information collected from the sources used
to develop the iron and steel survey receipt list (discussed in Section 3.1.3).

              The Agency used the following four general criteria to select sites that
encompassed the range of sectors and unit operations within the industry:

              1.      The site performed proposed MP&M operations in one of the industrial
                     sectors. To assess the variation of unit operations and water-use practices
                     across sectors, the Agency visited sites in 18 industrial sectors.

              2.      The site performed proposed MP&M operations that needed to be
                     characterized for development of the regulation.

              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 EPA was evaluating in developing the MP&M
                     technology options.

              The Agency also visited sites of various  sizes. EPA visited sites with wastewater
flows ranging from less than 200 gallons per day (gpd) to more than 1,000,000 gpd.

              EPA selected iron and steel sites to visit based on the type of site (steel forming
and finishing, integrated, non-integrated), the manufacturing operations at each facility, the type
of steel produced (carbon, alloy, stainless), and the wastewater treatment operations.  The
Agency wanted to visit all types of iron and steel manufacturing operations as well as all types of
wastewater treatment operations, including recently installed treatment systems.  After EPA
evaluated the completed surveys and in response to comments received on the proposed rule, the
Agency used information provided by the sites to select additional iron and steel sites to visit.

              Site-specific selection criteria are discussed in site visit reports (SVRs) prepared
for each site visited by EPA.  The SVRs are located in Sections 5.1 and 15.2 of the rulemaking
record.
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                                                                     3.0 - Data Collection Activities

3.2.2          Information Collected

              During the site visits, EPA collected the following types of information:

              •      Types of unit operations performed at the site and the types of metals
                    processed through these operations;

              •      Purpose of unit operations performed and purpose of 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;

              •      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 site. Nonconfidential SVRs can be found
in the MP&M rulemaking record (see Sections 5.1 and 15.2).

3.3           EPA MP&M Sampling Program

              The Agency conducted sampling episodes at 84 sites between 1986 and 2001 to
obtain data on the characteristics of wastewater and solid wastes. In addition, EPA performed
sampling episodes to assess the following: (1) the loading of pollutants to surface waters and
POTWs from facilities performing proposed MP&M operations; (2) the effectiveness of
technologies designed to reduce and remove pollutants from wastewater; and (3) the variation of
wastewater characteristics across unit operations, metal types processed in each unit operation,
and sectors. Table 3-4 indicates the number of sites sampled within each industrial sector. The
number of sampled sites presented in the table does not equal 84 because EPA conducted
multiple sampling episodes at some sites, and some sites had operations in multiple sectors.
Figure 3-2 presents the number of sites visited and sampled by industrial sector. Table 3-4 and
Figure 3-2 also include sites initially sampled as part of the iron and steel rulemaking, the results
of which were incorporated into the MP&M rulemaking.
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                                                                     3.0 - Data Collection Activities
                                      Table 3-4
           Number of Sites Sampled Within Each Proposed Industrial
Industrial Sectors
Aerospace
Aircraft
Bus and Truck
Electronic Equipment
Hardware
Household Equipment
Instruments
Job Shops
Miscellaneous Metal Products
Mobile Industrial Equipment
Motor Vehicle
Total Number
of Sites
Sampled
2
9
4
4
4
2
2
10
0
2
9
Industrial Sectors
Office Machines
Ordnance
Precious Metals and Jewelry
Printed Wiring Boards
Railroad
Ships and Boats
Stationary Industrial Equipment
Steel Continuous Electroplating"
Steel Forming and Finishing: Wire
Drawing"

Total Number
of Sites
Sampled
2
3
2
5
4
3
4
5
2


Source:  MP&M and Iron and Steel Sampling Episodes.
"The number of sites sampled is listed separately for steel forming and finishing and steel continuous electroplater
sites instead of by industrial sector.
3.3.1
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 proposed MP&M operations EPA was evaluating for
                    the MP&M regulation;

             •      The site processed metals through proposed MP&M operations for which
                    the metal type/unit operation combination needed to be characterized for
                    the sampling database;

             •      The site performed in-process source reduction, recycling, or end-of-pipe
                    treatment technologies that EPA was evaluating for technology option
                    development; and

             •      The site performed unit operations in a sector that EPA was evaluating for
                    the MP&M regulation.

The Agency also sampled at sites of various sizes, with wastewater flows ranging from less than
200 gpd to more than 1,000,000 gpd.
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                                                                     3.0 - Data Collection Activities

              EPA selected iron and steel sampling sites using the following criteria:

              •      The site performed operations either currently regulated under 40 CFR 420
                    or identified in the Preliminary Study or otherwise identified as iron and
                    steel operations;

              •      The site performed high-rate recycling, in-process treatment, or end-of-
                    pipe treatment operations that EPA believed may represent potential
                    model pollutant control technology; and

              •      The site's compliance monitoring data indicated that it was among the
                    better performing pollutant control systems in the industry, based on
                    comparisons of monitoring data from other facilities with limits from the
                    1982 regulation in their permits.

              In response to comments received on the proposed rule, EPA conducted
wastewater sampling at four additional sites between November 2000 and April 2001.  EPA
selected these additional sites for the following reasons:

              •      As a collaborative effort between the American Iron and Steel Institute and
                    EPA, to supplement the 1997/1998 sampling results by further
                    characterizing raw sinter plant wastewater, specifically the amount of
                    dioxins and furans generated by this industry, and to evaluate wastewater
                    treatment system performance; and

              •      To further characterize untreated wastewater generated by continuous
                    casting and hot forming operations at non-integrated steel mills.

              After it selected a site 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.  EPA prepared the SAPs to ensure samples collected would be
representative of the sampled waste streams.  The SAPs 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.

3.3.2          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;
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                                                                    3.0 - Data Collection Activities

             •      Production data corresponding to each sample of wastewater from
                    proposed MP&M operations;

             •      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
                    that were not included in the SVR; and

             •      Temperature and pH of the sampled waste streams.

             EPA documented all data collected during sampling episodes in the sampling
episode report (SER) for each sampled site. SERs are located in Sections 5.2 and 15.3 of the
rulemaking record.

3.3.3         Sample Collection and Analysis

             The Agency collected, preserved, and transported all samples according to EPA
protocols as specified in EPA's Sampling and Analysis Procedures for Screening of Industrial
Effluents for Priority Pollutants (1) (Section 4.2, DCN 17334) and the MP&M Quality
Assurance Project Plan (QAPP) (Section 4.4, DCN 17366). These documents are located in the
rulemaking record. Appendix B presents the analytical methods and baseline values.

             In general, EPA collected composite samples from wastewater streams with
compositions that the Agency expected to vary over the course of a production period (e.g.,
overflowing rinse waters, wastewater from continuous recycling and treatment systems).  The
Agency collected grab samples from unit operation baths or rinses that the facility did not
continuously discharge and that the Agency did not expect to vary over the course of a
production period.  EPA also collected composite samples of wastewater treatment sludge at 11
facilities. EPA collected the required types of quality control samples as described in the MP&M
QAPP, such as blanks and duplicate samples, to verify the precision and accuracy of sample
analyses.

             The Agency shipped samples via overnight air transportation to EPA-approved
laboratories, where the samples were analyzed for metal and organic pollutants and additional
parameters (including several water quality parameters). EPA analyzed metal pollutants  using
EPA Method  1620 (2), volatile organic pollutants using EPA Method 1624 (3), and semivolatile
organic pollutants using EPA Method  1625 (4). Tables 3-5 and 3-6 list the metal and organic
pollutants, respectively, analyzed using these methods.  Table 3-5 also lists additional metal
pollutants that EPA analyzed in the MP&M sampling program, but, as specified by EPA Method
1620, were not subject to the rigorous  quality assurance/quality control procedures established by
the QAPP.
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                                                                3.0 - Data Collection Activities
                                    Table 3-5

     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 Constituents3 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
Source: EPA Method 1620.
aAnalyses for these metals were used primarily for screening purposes
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                                                           3.0 - Data Collection Activities
                                 Table 3-6

   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 DISULFIDE
CHLOROACETONITRILE
CHLOROBENZENE
CHLOROETHANE
CHLOROFORM
CHLOROMETHANE
CIS-1,3-DICHLOROPROPENE
CROTONALDEHYDE
DIBROMOCHLOROMETHANE
DIBROMOMETHANE
DIETHYL ETHER
ETHYL CYANIDE
ETHYL METHACRYLATE
ETHYLBENZENE
lODOMETHANE
ISOBUTYL ALCOHOL
M-XYLENE
METHYL METHACRYLATE
METHYLENE CHLORIDE
O+P-XYLENE
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 -DICHLOROETH ANE
1,1 -DICHLOROETHENE
1,1,1 -TRICHLOROETH ANE
1,1,1,2-TETRACHLOROETHANE
1,1,2-TRICHLOROETHANE
1,1,2,2-TETRACHLOROETHANE
1,2-DIBROMOETHANE
1,2-DICHLOROETHANE
1,2-DICHLOROPROP ANE
1,2,3 -TRICHLOROPROP ANE
1,3-BUTADIENE, 2-CHLORO
1,3 -DICHLOROPROP ANE
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
ACROLEIN
                                   3-43

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                                                            3.0 - Data Collection Activities
                           Table 3-6 (Continued)
                  Semivolatile Organic Constituents (EPA Method 1625)
ACENAPHTHENE
ACENAPHTHYLENE
ACETOPHENONE
ALPHA-TERPINEOL
ANILINE
ANILINE, 2,4,5-TRIMETHYL-
ANTHRACENE
ARAMITE
BENZANTHRONE
BENZENETHIOL
BENZIDINE
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
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
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
O-CRESOL
O-TOLUIDINE
O-TOLUIDINE, 5-CHLORO-
P-CHLOROANILINE
P-CRESOL
P-CYMENE
P-DIMETHYLAMINOAZOBENZENE
P-NITROANILINE
PENTACHLOROBENZENE
PENTACHLOROPHENOL
PENTAMETHYLBENZENE
PERYLENE
PHENACETIN
                                    3-44

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                                                              3.0 - Data Collection Activities
                            Table 3-6 (Continued)
                    Semivolatile Organic Constituents (EPA Method 1625)
 ISOPHORONE
 ISOSAFROLE
 LONGIFOLENE
 MALACHITE GREEN
 MESTRANOL
 METHAPYRILENE
 METHYL METHANESULFONATE
 N-DECANE
 N-DOCOSANE
 N-DODECANE
 STYRENE
 THIANAPHTHENE
 THIOACETAMIDE
 THIOXANTHE-9-ONE
 TOLUENE, 2,4-DIAMINO-
 TRIPHENYLENE
 TRIPROPYLENEGLYCOL METHYL ETHER
 1 -BROMO-2-CHLOROBENZENE
 1 -BROMO-3 -CHLOROBENZENE
 1 -CHLORO-3 -NITROBENZENE
 1 -METHYLFLUORENE
 1 -METHYLPHENANTHRENE
 1 -NAPHTHYL AMINE
 1 -PHENYLNAPHTH ALENE
 1,2-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
 1,3 -DICHLORO-2-PROP ANOL
 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
PHENANTHRENE
PHENOL
PHENOL, 2-METHYL-4,6-DINITRO-
PHENOTHIAZINE
PRONAMIDE
PYRENE
PYRIDINE
RESORCINOL
SAFROLE
SQUALENE
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 -METHYLCHOL ANTHRENE
3-NITRO ANILINE
3,3 '-DICHLOROBENZIDINE
3,3 '-DIMETHOXYBENZIDINE
3,6-DIMETHYLPHEN ANTHRENE
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
N-NITRODOSI-N-PROPYL AMINE
Source: EPA Methods 1624 and 1625.
                                      3-45

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                                                                     3.0 - Data Collection Activities

The Agency used these metals analyses for screening purposes and did not select the metals for
regulation in this rulemaking (see Section 7.0). EPA analyzed additional parameters, including
several water quality parameters, using analytical methods contained in EPA's Methods for
Chemical Analysis of Water and Wastes (5). Table 3-7 lists these parameters, along with the
method and technique used to analyze for each parameter. Method descriptions are included in
the MP&M QAPP.  The specific parameters measured in each sample are listed in the SER 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 QAPP.  EPA reviewed all
analytical data to ensure that these measures were followed and that the resulting data were
within the QAPP-specified acceptance criteria for accuracy and precision.

             As discussed previously, upon receipt and review of the analytical data for each
site, EPA prepared an SER to document the data collected during sampling,  the analytical results,
and the technical analyses of the results. The SAPs and correspondence with site personnel are
included as appendices to the SERs.

3.4          Other Sampling Data

             The Association of American Railroads (AAR), the Hampton Roads Sanitation
District (HRSD), the Los Angeles County Sanitation Districts (LACSD), and the Association
Connecting Electronic Industries (TPC) proposed  potential sampling sites to  the Agency, and
EPA visited these sites to identify candidates for sampling. After conducting site visits, EPA
selected six sites for sampling episodes.

             EPA selected the six sites to characterize end-of-pipe treatment technologies in
metal finishing and aircraft parts job shops and the railroad and shipbuilding industrial sectors.
AAR sampled a railroad line  maintenance that used dissolved air flotation (DAF) to treat MP&M
process wastewater. HRSD sampled a ship manufacturer that uses DAF, chemical precipitation,
and cyanide destruction to treat process wastewater. LACSD sampled two metal finishing job
shops and one aircraft parts manufacturing job  shop. EPA selected the LACSD sites to provide
data for cyanide treatment and also conducted effluent variability sampling at one of the metal
finishing job shops. The IPC site is a printed wiring board facility that uses  chemical
precipitation with chelation breaking, cyanide destruction and batch treatment to treat process
wastewater.

             EPA prepared detailed SAPs based on the information collected during the six  site
visits, and AAR, HRSD and LACSD collected the wastewater samples. EPA also prepared the
sampling episode reports. In addition to the wastewater samples, sampling personnel
documented the collection date and time, sample  flow data, treatment unit design and operating
parameters, and temperature and pH of the sampled waste streams. All data collected during
sampling episodes are documented in the SER for each sampled site, which  are located in the
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                                                              3.0 - Data Collection Activities
                                   Table 3-7
   Additional Parameters Measured Under the MP&M Sampling Program
Parameter
Acidity
Alkalinity
Ammonia as Nitrogen
BOD 5-Day (Carbonaceous)
Chemical Oxygen Demand (COD)
Chloride
Chromium, Hexavalent
Cyanide, Amenable
Cyanide, Total
Cyanide, Weak Acid Dissociable (WAD)
Fluoride
Nitrogen, Total Kjeldahl
Oil and Grease
Oil and Grease (as HEM)
pH
Phenolics, Total Recoverable
Phosphorus, Total
Sulfate
Sulfide, Total
Total Dissolved Solids (TDS)
Total Organic Carbon (TOC)
Total Petroleum Hydrocarbons (as SGT-HEM)
Total Suspended Solids (TSS)
Ziram (zinc dimethyldithiocarbamate)
EPA Method
305.1
310.1
350.1
405.1
410.1
410.2
325.3
218.4
335.1
335.2
1677
340.2
351.2
413.2
1664
150.1
420.2
365.4
375.4
376.1,376.2
160.1
415.1
1664
160.2
630.1
Source: EPA Methods for Chemical Analysis of Water and Wastes (5).
                                      3-47

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                                                                   3.0 - Data Collection Activities

MP&M rulemaking record (see Sections 5.2 and 15.3). EPA combined these data with data
collected from the MP&M sampling program.  For a discussion of sample collection and the
sampling protocols for the IPC site, see the SER (DCN 16684) in Section 15.3.7 of the MP&M
rulemaking record.

             AAR, HRSD, and LACSD collected, preserved, and transported all samples
according to EPA protocols as specified in EPA's  Sampling and Analysis Procedures for
Screening of Industrial Effluents for Priority Pollutants (Section 4.2, DCN 17334) and the
MP&M QAPP.  Procedures for shipping and analysis of the samples were similar to those
discussed in Section 3.3 with the  exception that some samples were shipped directly to internal
sanitation district laboratories for analysis.  Pollutant parameters and analytical methods were
agreed upon by EPA, AAR, HRSD, and LACSD and were treated as equivalent to those in the
EPA MP&M sampling program.

3.5          Other Industry-Supplied Data

             EPA evaluated other industry data in developing the MP&M effluent guidelines.
The data sources reviewed included:

             •      Public comments to the May 1995 Proposal, January 2001 proposal, and
                    June 2002 NOD A;

             •      The Metal  Finishing F006 Benchmark Study (6);

             •      Data supporting the Final Rule for the F006 Accumulation Time
                    Extension (65 FR 12377, March 8, 2000);

             •      Data provided by the Aluminum Anodizing Council (AAC), the American
                    Wire Producers Association (AWPA), and the Aerospace Association; and

             •      Surveys provided by the North Carolina Pretreatment Consortium.

             EPA also reviewed data from stormwater pollution prevention plans provided by
several shipbuilding sites, dry dock data from a shipbuilding site, and data from periodic
compliance monitoring reports/discharge monitoring reports for 19 sites that were part of the
Agency's wastewater sampling program.

             The Agency included data submitted with comments on the 1995 MP&M
Proposed Rule, the 2001 MP&M Proposed Rule, or the 2002 MP&M NOD A in the
establishment of effluent limitations and standards if they met the following criteria:

             •      Measurements of daily effluent concentration were provided;
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                                                                    3.0 - Data Collection Activities

             •      Data represented effluent from a treatment system equivalent to EPA's
                    BAT options;

             •      Samples represented fully treated effluent (as defined by Options 2, 6, or
                    10 as appropriate); and

             •      Treated pollutants were identified and/or unit operations contributing
                    pollutants were described.

             In addition, the North Carolina Pretreatment Consortium conducted a survey of
POTWs in that state. EPA evaluated the results of these surveys and used the results as
appropriate to verify and supplement information from the previous MP&M POTW survey on
loadings, number of facilities performing proposed MP&M operations served, and administrative
costs. The results of EPA's analysis of this data is in the  Comment Response Document, Issue
Codes 4 and 20G. The AMSA and North Carolina Pretreatment Consortium surveys can be
found in Section 17.6 of the rulemaking record.

3.6          Other Data Sources

             In developing the MP&M effluent guidelines, EPA evaluated the following
existing data sources:

             1.     EPA Engineering and Analysis Division (EAD) databases from
                    development of effluent guidelines for miscellaneous metals industries;

             2.     The Fate  of Priority Pollutants in Publicly Owned Treatment Works (50
                    POTW Study) database;

             3.     The Office  of Research and Development (ORD) National Risk
                    Management and Research Laboratory (NRMRL) treatability database;

             4.     The Domestic Sewage Study;

             5.     The Toxics Release Inventory (TRI) database; and

             6.     Discharge Monitoring Reports (DMR) from EPA's Permit Compliance
                    System (PCS).

These data sources and their uses for the development of the MP&M effluent guidelines are
discussed below.
                                         3-49

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                                                                     3.0 - Data Collection Activities

3.6.1          EPA/EAD Databases

              As discussed in Section 2.0, EPA had earlier promulgated effluent guidelines for
13 metals industries.  In developing these past effluent guidelines, EPA collected wastewater
samples to characterize the unit operations and treatment systems at sites in these industries.
Facilities performing proposed MP&M operations operate many of the same or similar sampled
unit operations and treatment systems; therefore, EPA evaluated these data for transfer to the
MP&M effluent guidelines development effort.

              For the pollutant loading and wastewater characterization efforts, EPA reviewed
the data collected for unit operations performed at both facilities performing proposed MP&M
operations and at sites in the other metals industries. EPA reviewed the  Technical Development
Documents (TDDs), sampling episode reports, and supporting rulemaking record materials for
the other metals industries to identify available data. EPA used these data for the preliminary
assessment of the industry, but did not use these data to estimate pollutant loadings because EPA
obtained sufficient data from the MP&M sampling program to characterize the proposed MP&M
operations.

              For the MP&M technology effectiveness assessment effort, EPA reviewed
sampling data collected to characterize treatment systems for the development of effluent
guidelines for miscellaneous metals industries.  For several previous effluent guidelines, EPA
used treatment data from metals industries to  develop the Combined Metals Database (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
treatment systems. EPA did not use these data in developing the MP&M technology
effectiveness concentrations, since the Agency collected sufficient data from facilities performing
proposed MP&M operations to develop technology effectiveness concentrations.

3.6.2          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 (7), referred to as the 50-POTW Study. The purpose of this study was
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:

              •       The quantity of priority pollutants in the influent to POTWs;

              •       The quantity of priority pollutants discharged from the POTWs;

              •       The quantity of priority pollutants in the effluent from intermediate
                     process streams; and
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                                                                    3.0 - Data Collection Activities

             •      The quantity of priority pollutants in the POTW sludge streams.

EPA used the data from this study to assess removal by POTWs of pollutants of concern (see
Section 7).  To provide consistency for data analysis and establishment of removal efficiencies,
EPA reviewed the 50-POTW Study and standardized the reported minimum levels of
quantitation (MLs) for use in the MP&M final rule. EPA's review of the 50-POTW Study is
described in more detail in the development document for the MP&M proposed regulation
located in Section 7.2 of the rulemaking record, DCN 16377, and in memoranda located in
Section 6.4 of the rulemaking record.

3.6.3         National Risk Management Research Laboratory (NRMRL) Treatability
             Database

             EPA's ORD developed the NRMRL (formerly 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 POTWs as
well as industrial facilities for various pollutants.  The database includes physical and chemical
data for each pollutant, the types of treatment used for specific pollutants, the types of wastewater
treated, the size of the POTW or industrial plant, and the treatment concentrations achieved.
EPA used the NRMRL database to estimate pollutant reductions achieved by POTWs for MP&M
pollutants of concern that were not found in the 50-POTW database. The Agency used these
percent removal estimates in calculating the pollutant loads removed by indirect discharging
facilities  performing proposed MP&M operations. Because the 50-POTW database contained
sufficient data, EPA did not use these percent removal estimates in the pass-through analysis.
EPA used only treatment technologies representative of typical POTW secondary treatment
operations (i.e., activated sludge, activated sludge with filtration, aerated  lagoons).  The Agency
further edited these files to include information pertaining only to domestic or industrial
wastewater. EPA used pilot-scale and full-scale data,  and eliminated bench-scale data and data
from less reliable references.

3.6.4         The Domestic Sewage Study

             In February 1986, EPA issued the Report to Congress on the Discharge of
Hazardous Wastes to Publicly  Owned Treatment Works (8), 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.  These pollutants 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 that 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 miscellaneous categories that were related to metals industries,  namely the motor
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                                                                     3.0 - Data Collection Activities

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
1989 Preliminary Data Summary (PDS) for the MP&M rulemaking.

3.6.5         Toxics Release Inventory (TRI) Database

              The 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 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 600 chemicals and 30
chemical categories.

              EPA considered using the TRI database in developing the MP&M effluent
guidelines. However, EPA did not use TRI data on wastewater discharges from facilities
performing proposed MP&M operations because sufficient data were not available for effluent
guidelines development. Also, many of the reported discharges are estimates, not based on
measurement.  For example, in developing the MP&M effluent guidelines, EPA uses wastewater
influent concentrations to characterize a facility's wastewater and to calculate treatment
efficiency (i.e., percent removal across the treatment system). The TRI database does  not provide
concentrations for the influent to a facility's treatment system.  EPA also did not use the data on
wastewater discharge because many facilities performing proposed MP&M operations do not
meet the reporting thresholds for the TRI database.

3.6.6         Discharge Monitoring Reports from EPA's Permit Compliance System

              The PCS provides information on companies which have been issued permits to
discharge wastewater into surface water. Users can review information on when a permit was
issued and expires, how much the company is permitted to discharge, and the actual monitoring
data showing what the company has discharged. Respondents to MP&M surveys and
commentors on the May 1995 proposal, January 2001 proposal, and June 2002 NOD A supplied
facility specific DMR data. In addition, EPA retrieved facility limits and process wastewater
monitoring data from facilities performing proposed MP&M operations for selected pollutant
parameters (e.g., metals, oil and grease). EPA used DMR data to estimate industry baseline
pollutant loadings.  Section 12.3 discusses the estimation of baseline pollutant loadings using
PCS data.
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                                                                   3.0 - Data Collection Activities

3.7          References

1.            U.S. Environmental Protection Agency. Sampling and Analysis Procedures for
             Screening of Industrial Effluents for Priority Pollutants, April 1977.

2.            U.S. Environmental Protection Agency. Method 1620 Draft - Metals by
             Inductively Coupled Plasma Atomic Emission Spectroscopy and Atomic
             Absorption Spectroscopy, September  1989.

3.            U.S. Environmental Protection Agency. Method 1624 Revision C - Volatile
             Organic Compounds by Isotope Dilution GCMS, June 1989.

4.            U.S. Environmental Protection Agency. Method 1625 Revision C - Semivolatile
             Organic Compounds by Isotope Dilution GCMS, June 1989.

5.            U.S. Environmental Protection Agency. Methods for Chemical Analysis of Water
             and Wastes. EPA-600/4-79-020, Washington, DC, March 1979.

6.            U.S. Environmental Protection Agency. Metal Finishing F006 Benchmark Study.
             Washington, DC, September 1998.

7.            U.S. Environmental Protection Agency. Fate of Priority Pollutants in Publicly
             Owned Treatment Works. EPA 440/1-82/303, Washington, DC, September 1982.

8.            U.S. Environmental Protection Agency. Report to Congress on the Discharge of
             Hazardous Wastes to Publicly Owned Treatment Works.  EPA 530-SW-86-004,
             Washington, DC, February 1986.

9.            U.S. Environmental Protection Agency. Development Document for Final
             Effluent Limitations Guidelines and Standards for the Iron and Steel
             Manufacturing Point Source Category (EPA-821-R-02-004).
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                                                                         4.0 - Industry Description

4.0           INDUSTRY DESCRIPTION

              As discussed in Section 1.0, EPA has promulgated effluent limitations for the
MP&M Point Source Category that regulate directly discharged process wastewaters from oily
operations at facilities engaged in manufacturing, rebuilding, or maintenance of metal parts,
products, or machines for use in one or more of the following 16 industrial sectors:

              •       Aerospace;
              •       Aircraft;
              •       Bus and Truck;
              •       Electronic Equipment;
              •       Hardware;
              •       Household Equipment;
              •       Instruments;
              •       Mobile Industrial Equipment;
              •       Motor Vehicle;
              •       Office Machine;
              •       Ordnance;
              •       Precious Metals and Jewelry;
              •       Railroad;
              •       Ships and Boats;
              •       Stationary Industrial Equipment; and
              •       Miscellaneous Metal Products.

              This section describes these facilities. For the final rule, EPA evaluated facilities
in the 16 MP&M industrial sectors above and Job Shop, Printed Wiring Board, and Steel
Forming and Finishing industrial sectors (i.e., Iron & Steel Wire Drawers and Steel
Electroplaters). For the purposes of this section, EPA is identifying all facilities evaluated for the
final rule as "MP&M facilities." Section 4.1 presents an overview of MP&M facilities; Section
4.2 provides a general discussion of unit operations performed, types of metal processed, and
volumes of wastewater discharged at MP&M facilities; Section 4.3 discusses trends at MP&M
facilities; and Section 4.4 lists the references used in this section.

4.1           Overview of MP&M facilities

              This subsection discusses the number and size of MP&M facilities evaluated for
regulation, the geographic distribution of these facilities, the number of wastewater-discharging
MP&M facilities, and the number of MP&M facilities that do not discharge wastewater.
                                           4-1

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                                                                           4.0 - Industry Description

4.1.1          Number and Size of MP&M Facilities

              Based on information in the MP&M survey database, there are an estimated
57,000 MP&M facilities in the United States.1 Results of the detailed surveys indicate there are
an estimated 44,000 MP&M facilities that discharge process wastewater (i.e., wastewater-
discharging MP&M facilities). The remaining 13,000 facilities fall into one of three categories:
zero dischargers, non-water-users, or contract haulers. A zero discharger is a facility that does
not discharge process wastewater to a treatment system, a non-water-user is a facility that does
not use process water in their unit operations, and a contract hauler is a facility that has all of
their process wastewater contract hauled. For the purposes of the evaluating options for the final
rule, EPA considers MP&M facilities that discharge wastewater exclusively to privately owned
treatment works to be zero dischargers that contract haul their wastewater to centralized
wastewater treatment facilities.

              Wastewater-discharging MP&M facilities range in size from facilities with less
than 10 employees to facilities with thousands of employees. As shown in Figure 4-1, 91 percent
of the wastewater-discharging MP&M facilities have 500 or fewer employees.  These facilities
discharge 55 percent (i.e., 43 billion gallons per year) of the total annual wastewater discharge
for the MP&M industry.  The 9 percent of the wastewater-discharging MP&M facilities that have
more than 500 employees discharge 35 billion gallons of wastewater annually,  or 45 percent of
the total annual wastewater discharge for the MP&M category.
'More information on how the MP&M survey database was used to generate national estimates is in the MP&M
rulemaking record (see Section 10.0, DCN 16118 and Section 19.5, DCNs 36086 and 36087).

                                            4-2

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                                                                              4.0 - Industry Description
       60 Y|
       50-
       40-
       30-
       20-
       10-
             47%
             <=10
                                                       D Percentage of MP&M Wastewater-Discharging Sites

                                                       D Percentage of Total Annual MP&M Discharge Flow
                       11-50
                                51-100      101-500    501-1,000    1,001-5,000  5,001-10,000    >10,000
                                          Number of Employees
4.1.2
               Source: MP&M Survey Database.
               Note:   There are 44,000 wastewater-discharging MP&M facilities. Total MP&M wastewater
                      flow is 78.2 billion gallons per year.

          Figure 4-1. Percentage of Wastewater-Discharging MP&M facilities and
           Percentage of Annual Wastewater Discharge by Number of Employees
Geographic Distribution
               Wastewater-discharging MP&M facilities are located throughout the United
States.  They are mostly concentrated in industrialized areas, with the highest concentration of
facilities in California, Pennsylvania, and Illinois.  The following map shows the estimated
number of wastewater-discharging MP&M facilities located in each EPA region.
                                              4-3

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                                                                     4.0 - Industry Description
                                            #J= EPA Region number
                                            3= Number of Wastewater-Discharging
                                                MP&M Sites in EPA Region
   Figure 4-2. Estimated Number of Wastewater-Discharging MP&M facilities by EPA
                                       Region
4.1.3
Wastewater-Discharging Facilities
             EPA evaluated MP&M facilities in 20 industrial sectors for the final rule. Table 4-
1 summarizes the number of wastewater-discharging MP&M facilities by industrial sector.
Because some MP&M facilities perform operations or make products used in more than one
sector, the sum of wastewater-discharging MP&M facilities by sector exceeds the total number of
wastewater-discharging MP&M facilities identified in the surveys. As shown in Table  4-1, the
ordnance sector has the smallest number of wastewater-discharging facilities (405) and the job
shop sector has the largest number of wastewater-discharging facilities (14,589).
                                         4-4

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                                                                                    4.0 - Industry Description
                                             Table 4-1
                 Wastewater-Discharging MP&M facilities by Sector
Sector
Aerospace
Aircraft
Bus and Truck
Electronic Equipment
Hardware
Household Equipment
Instruments
Iron and Steel Wire Drawers'5 ' °
Job Shop c
Miscellaneous Metal Products
Mobile Industrial Equipment
Motor Vehicle
Office Machine
Ordnance
Precious Metals and Jewelry
Printed Circuit Boards °
Railroad
Ships and Boats
Stationary Industrial Equipment
Steel Electroplatersb'c
Estimated Number of MP&M Facilities That
Discharge Process Wastewater"
712
1,598
3,522
2,644
6,223
3,137
3,902
153
14,589
5,316
1,079
13,070
1,092
405
1,860
1,456
5,181
1,367
1,724
28
Source:  MP&M Survey Database.
a Because some facilities perform unit operations in more than one sector, the sum of facilities by sector exceeds the
total number of facilities that discharge wastewater (44,000).
b Technical surveys for these facilities did not include sector information; therefore, they were listed separately for
this table.
0 These industrial sectors are not included in the final rule.
                                                 4-5

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                                                                             4.0 - Industry Description
              In addition to description by industrial sector, MP&M operations2 that were
proposed for regulation can be described by two types of activities: manufacturing and
rebuilding/maintenance.
              •      Manufacturing is the series of unit operations necessary to produce metal
                     products, and is generally performed in a production environment.

              •      Rebuilding/maintenance 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 products. These operations are intended to keep metal products in
                     operating condition and can be performed in either a production or a
                     nonproduction environment.

              Figure 4-3 presents the percentage of wastewater-discharging MP&M facilities
and percentage of the total annual wastewater discharge by activity. Eighty-two percent of the
annual wastewater discharge is discharged by facilities with only manufacturing operations.
These facilities represent 35 percent of the total wastewater-discharging MP&M facilities. The
highest percentage of the MP&M facilities (i.e., 50 percent) have only rebuilding and
maintenance operations.
2EPA evaluated a number of unit operations for the May 1995 proposal, January 2001 proposal, and June 2002
Notice of Data Availability (NODA) (see Tables 4-3 and 4-4). However, EPA selected a subset of these unit
operations for regulation in the final rule (see section 1.0). For this section, the term "proposed MP&M operations"
means those operations evaluated for the two proposals, NOD A, and final rule. The term "Final MP&M operations"
means those operations defined as "oily operations" (see Section 1.0, 40 CFR 438.2(f), and Appendix B to Part 438)
and regulated by the final rule.

                                             4-6

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                                                                               4.0 - Industry Description
         70-
         60-
         50-
       m
       o
       s
         40-
         30-
         20-
         10-
D Percentage of MP&M Wastewater-
 Discharging Sites

D Percentage of Total Anuual MP&M
 Discharge Flow
                  Manufacturing and
                Rebuilding/Maintenance
                   Manufacturing Only

                       Activity
Rebuilding/Maintenance Only
               Source: MP&M Survey Database.
               Note:   There are 44,000 wastewater-discharging MP&M facilities.  Total MP&M wastewater
                      flow is 78.2 billion gallons per year.

          Figure 4-3. Percentage of Wastewater-Discharging MP&M facilities and
                      Percentage of Total Annual Discharge by Activity
               Wastewater-discharging MP&M facilities include direct dischargers, indirect
dischargers, and those that are both direct and indirect dischargers.  A direct discharger is a
facility that discharges wastewater to a surface water (e.g., river, lake, ocean). An indirect
discharger is a facility that discharges wastewater to a publicly owned treatment works (POTW).
Figure 4-4 presents the percentage of wastewater-discharging MP&M facilities and the
percentage of the total annual wastewater discharge by discharge status.  This figure shows that
the highest percentage of wastewater-discharging MP&M facilities are indirect dischargers, and
those facilities account for 85 percent of the total annual discharge from all MP&M facilities.
                                              4-7

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                                                                              4.0 - Industry Description
          100-


           90-


           80-


           70-


           60-


  Percentage  50-


           40-


           30-


           20-


           10-
DPercentage of MP&M Wastewater-Dischargmg Sites
D Percentage of Total Annual MP&M Discharge Flow
                    Direct and Indirect
                                                Direct
                                           Discharge Destination
                                                                         Indirect
               Source: MP&M Survey Database.
               Note:   There are 44,000 wastewater-discharging MP&M facilities. Total MP&M wastewater
                      flow is 78.2 billion gallons per year.

          Figure 4-4. Percentage of Wastewater-Discharging MP&M facilities and
                 Percentage of Total Annual Discharge by Discharge Status
               Wastewater discharge flow rates for MP&M facilities range from less than 100
gallons per year to greater than 100 million gallons per year. Figure 4-5 presents the percentage
of wastewater-discharging MP&M facilities and the percentage of the annual MP&M wastewater
discharge by range of wastewater flow rates. As this figure shows, MP&M facilities discharging
more than one million gallons per year (approximately 12 percent of the total facilities) account
for approximately 95 percent of the total annual wastewater discharge for all MP&M facilities.
In contrast, facilities discharging less than 100,000 gallons per year (approximately 62 percent of
the total facilities) account for less than one percent of the total annual wastewater discharge for
all MP&M facilities.
                                              4-8

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                                                                              4.0 - Industry Description
50-
45-
40-
35-
30-
25-
20-
15-
10-


X
X
X

47%


D Percentc
• Percentc
ge of MP&M Wastewater-Discharging Sit
ge of Total Annual MP&M Discharge Flow
3S




30%




5%
ft,
_L£^










-|yo,
10%

^^
I
t



0


J — ^
^ 	










18%





,
i

y%










I
3%





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^ —





1





X

4.1.4
              0-100     101-1,000   1,001-10,000    10,001-     100,001-    1,000,001-   10,000,001-  > 100,000,000
                                          100,000     1,000,000    10,000,000   100,000,000
                                       Discharge Flow Range (GPY)
               Source:  MP&M Survey Database.
               Note:   There are 44,000 wastewater-discharging MP&M facilities.  Total MP&M wastewater
                      flow is 78.2 billion gallons per year.

          Figure 4-5. Percentage of Wastewater-Discharging MP&M facilities and
            Percentage of Total Annual MP&M Discharge by Flow Rate Range
Non-Wastewater-Discharging Facilities
              Based on the results of the detailed MP&M surveys, an estimated 13,000 MP&M
facilities either generate process water and do not discharge wastewater (i.e., zero discharge or
contract haulers) or do not use process water (dry facilities).  Information from the MP&M
detailed surveys, site visits, and technical literature indicates these facilities achieve zero
discharge of process wastewater in one of the following ways:

              •       Contract haul all process wastewater generated on site;

              •       Discharge process wastewater to either on-site septic systems or deep-well
                      injection systems;
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                                                                          4.0 - Industry Description

              •       Perform end-of-pipe treatment and reuse all process wastewater generated
                     on site;

              •       Perform either in-process or end-of-pipe evaporation to eliminate
                     wastewater discharges; or

              •       Perform in-process recirculation and recycling to eliminate wastewater
                     discharges.

              As discussed in Section 3.0, EPA mailed the 1989 detailed survey to a probability
sample of 50 screener respondents that reported using but not discharging process water. Based
on the survey responses, 5 of these facilities contract hauled all wastewater generated on site, 8
actually discharged process wastewater, 18 had no process wastewater discharges, and 19 were
not engaged in proposed MP&M operations. The Agency also mailed the 1989 detailed survey
to an additional 24 screener respondents that reported using but not discharging process water.
As discussed in Section 3.0, EPA selected these facilities because they performed unit operations
that were not expected to be characterized sufficiently by detailed surveys mailed to other
facilities.  Of the additional 24, 14 actually discharged process wastewater, 2 had no process
wastewater discharges, and 8 were not engaged in proposed MP&M operations. Of the 74
screener respondents that received the 1989 detailed survey, only 20 reported no discharge of
process water.

              In addition to the 20 facilities discussed above that do not discharge process
wastewater, 205 of the 1996 screener survey respondents reported eliminating wastewater
discharges by in-process or end-of-pipe evaporation, end-of-pipe treatment and reuse, in-process
recirculation and recycling, or other unspecified means. Figure 4-6 shows the percentage of the
facilities using each type of zero discharge method. Note that Figure 4-6  provides the percentage
of survey respondents, not industry percentages, because this information was available for only
a subset of the industry. The methods used by the 225 survey facilities to eliminate wastewater
discharges are discussed below.

              In-Process or End-Of-Pipe Evaporation.  Forty-one percent of the screener
survey respondents (i.e., 92 respondents) reported discharging wastewater to either evaporators,
on-site ponds, or lagoons to evaporate process wastewater.  None of these facilities reported
recovering the process wastewater. Facilities reported contracting for off-site disposal of sludge
from the evaporation units.

              End-Of-Pipe Treatment and Reuse. Eight percent of the screener survey
respondents (i.e., 18 respondents) reported eliminating wastewater discharges through end-of-
pipe treatment and reuse of all  wastewater generated on site.
                                           4-10

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                                                                           4.0 - Industry Description
                     Unknown M ethods
                           12%
                                                                 In-Process orEnd-Of-
                                                                   Pipe Evap oration
                                                                       41%
                       In-Process
                     Recirculation and
                       Recy cling
                          23%
                                         End-Of-Pipe
                                      Treatment and Reuse
              Note: There are 225 survey facilities that have eliminated wastewater discharge.

                  Figure 4-6.  Percentage of Screener Survey Respondents
                            Using Each Zero Discharge Method
              In-Process Recirculation and Recycling. Twenty-three percent of the screener
survey respondents (i.e., 52 respondents) reported eliminating wastewater discharges through in-
process recirculation and recycling. Several facilities used a stagnant bath in their heat treating
operations.  Some facilities used stagnant baths in their surface finishing operations (e.g., alkaline
cleaning and chemical conversion coating).  Make-up water is added to the stagnant baths to
account for losses of bath water through evaporation.

              Other. Sixteen percent of the screener survey respondents (i.e., 36 respondents)
reported eliminating wastewater discharge through a variety of other methods including land
application and septic tank systems or contract hauling through a centralized waste treater (CWT)
or privately owned treatment works (PrOTW).
4.2
Proposed MP&M Operations
              This subsection discusses the proposed MP&M operations and presents a brief
description of each unit operation. It also discusses the metals processed in proposed MP&M
operations, and presents an estimate of the annual wastewater discharge for each proposed
MP&M operations.
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                                                                          4.0 - Industry Description

4.2.1          Types of Unit Operations

              MP&M facilities perform several different types of unit operations and associated
rinses on metal parts, products, and machines. Section 4.2.2 describes these unit operations.

              The types of proposed MP&M operations include:

              •      Metal shaping;
              •      Surface preparation;
              •      Metal deposition;
              •      Organic material deposition;
              •      Surface finishing;
              •      Assembly;
              •      Dry dock; and
              •      Specialized printed wiring board operations.

              Metal shaping is a mechanical operation that alters the form of raw materials into
intermediate and final products. Surface preparation includes chemical and mechanical
operations that remove unwanted materials from or alter the chemical or physical properties of
the part surface prior to subsequent proposed MP&M operations. Metal deposition applies a
metal coating to the part surface by chemical or physical means. Organic material deposition
applies an organic material to the part by chemical or physical means. Facilities may perform
metal and organic material deposition to protect the surface from wear or corrosion, modify the
electrical properties of the surface, or alter the appearance of the surface.  Surface finishing
protects and seals the surface of the treated part from wear or corrosion by chemical means.
Facilities also may use surface finishing to alter the appearance of the part surface. Assembly is
performed throughout the manufacturing, rebuilding, or maintenance process.  Dry dock
operations are proposed MP&M operations performed at ship and boat facilities within dry docks
or similar structures and incorporate many types of proposed MP&M operations. Printed wiring
board unit operations are those specific to the manufacture or rebuilding/maintenance of wiring
boards (e.g., carbon black deposition, solder  flux cleaning, and photo image developing).
Specialized printed wiring board operations do not include those performed at assembly-only
facilities.  Table 4-2 lists examples of the different types of proposed MP&M operations.
                                           4-12

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                                                                         4.0 - Industry Description
                                       Table 4-2
                      Types of Proposed MP&M operations
Type of Unit Operations
Metal Shaping
Surface Preparation
Metal Deposition
Organic Material Deposition
Surface Finishing
Assembly
Dry Dock
Specialized Printed Wiring Board
Example
Machining, Grinding, Deformation
Alkaline Cleaning, Acid Treatment
Electroplating, Vapor Deposition
Painting
Chemical Conversion Coating
Testing (e.g., leak testing), Assembly
Welding
Solder Leveling, Photoresist Applications
              At a given MP&M facility, the specific unit operations and the sequence of
operations depend on many factors, including the activity at the facility (i.e., manufacturing,
rebuilding/maintenance), industrial sector, and type of product processed.  As a result, MP&M
facilities perform many different combinations and sequences of unit operations. For example,
MP&M facilities that repair, rebuild or maintain products often conduct 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).  In general, however, MP&M
products are processed in the following order:

              •     The raw material (e.g., bar stock, wire, rod, 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.  Facilities typically clean and
                    degrease the parts between some of the shaping operations to remove
                    lubricants, coolants, and metal fines.  Facilities also may  heat a part
                    between shaping operations to alter its physical characteristics.

              •     After shaping, the part typically undergoes some type of surface
                    preparation, such as alkaline cleaning, acid treatment (pickling), or barrel
                    finishing. The specific operation depends on the  subsequent unit
                    operations and the final use of the products. For example, prior to
                    electroplating, parts typically go through acid pickling (i.e., acid cleaning)
                    to prepare the part surface for electroplating.  Before assembly, parts
                    typically go through alkaline cleaning or barrel finishing. Parts go through
                    surface preparation at various stages of the production process.  Additional
                    cleaning and degreasing steps precede metal deposition, organic material
                    deposition, surface finishing, and assembly.
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                                                                         4.0 - Industry Description

              •      Metal and organic material deposition typically follow shaping and surface
                    preparation, and precede surface finishing and final assembly.  For
                    example, electroplating usually follows alkaline and acid treatment, while
                    painting usually follows phosphate conversion coating and alkaline
                    treatment.

              •      Surface finishing operations typically are performed after shaping and
                    surface preparation.  Some surface finishing is performed after metal
                    deposition.  For example, chromate conversion coating typically follows
                    acid cleaning, although this operation is sometimes performed as a sealant
                    operation after electroplating (e.g., chemical conversion coating of
                    cadmium plated parts).  Surface finishing also is done prior to  applying
                    organic coatings. For example, phosphate conversion coating  frequently
                    precedes painting to enhance the paint adhesion.

              •      Disassembly may be the first step in the rebuilding process. Assembly, on
                    the other hand, is done during many steps of the manufacturing and
                    rebuilding process to prepare the final product. Assembly also may
                    involve some final shaping (e.g., drilling and grinding) and surface
                    preparation (e.g., alkaline cleaning).  Final assembly usually is the last
                    operation prior to shipment to the customer.

              Some MP&M facilities conduct all of these types of unit operations in
manufacturing or rebuilding products, while others may perform only some types. For  example,
a facility that manufactures products used 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. Another hardware product
manufacturing facility may only clean and paint the parts. A third hardware product
manufacturing facility may only shape the parts, and perform only machining, cleaning, and
degreasing operations.

4.2.2          Description of Proposed MP&M Operations

              EPA described the operations above as either metal-bearing operations or oily
operations. This section describes each of the MP&M operations for which EPA considered new
regulations. Oily operations (as defined in 40 CFR 438.2(f)) are listed in Table 4-3. Metal-
bearing operations (as defined in 40 CFR 438.2(d)) are listed in Table 4-4.
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                                                                                    4.0 - Industry Description
                                             Table 4-3
                               List of MP&M Oily Operations
    Abrasive Blasting
    Adhesive Bonding
    Alkaline Cleaning for Oil Removal
    Alkaline Treatment Without Cyanide
    Aqueous Degreasing
    Assembly/Disassembly
    Burnishing
    Calibration
    Corrosion Preventive Coating
    Electrical Discharge Machining
    Floor Cleaning (In Process Area)
    Grinding
    Heat Treating
    Impact Deformation	
Iron Phosphate Conversion Coating
Machining
Painting-spray or Brush (Including Water Curtains)
Polishing
Pressure Deformation
Solvent Degreasing
Steam Cleaning
Testing (e.g., Hydrostatic, Dye Penetrant, Ultrasonic, Magnetic
Flux)
Thermal Cutting
Tumbling/Barrel Finishing/Mass Finishing/Vibratory Finishing
 Washing (Finished Products)
Welding
 Wet Air Pollution Control for Organic Constituents	
Note: This list is replicated at 40 CFR 438.2(f) with definitions at Appendix B to Part 438.
                                                 4-15

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                                                                                    4.0 - Industry Description
                                             Table 4-4
                        List of MP&M Metal-Bearing Operations
  1 Abrasive Jet Machining
  1 Acid Pickling Neutralization
  1 Acid Treatment With Chromium
  1 Acid Treatment Without Chromium

  • Alcohol Cleaning
  • Alkaline Cleaning Neutralization
  • Alkaline Treatment With Cyanide
  1 Anodizing With Chromium
  1 Anodizing Without Chromium
  1 Carbon Black Deposition
  1 Catalyst Acid Pre-dip
  • Chemical Conversion Coating Without Chromium
  • Chemical Milling (or Chemical Machining)
  • Chromate Conversion Coating (or Chromating)
  • Chromium Drag-out Destruction
  1 Cyanide Drag-out Destruction
  1 Cyaniding Rinse
  1 Electrochemical Machining
  1 Electroless Catalyst Solution
  1 Electroless Plating
  1 Electrolytic Cleaning
  1 Electroplating With Chromium
  1 Electroplating With Cyanide
  1 Electroplating Without Chromium or Cyanide
  1 Electropolishing
  1 Galvanizing/Hot Dip Coating
  1 Hot Dip Coating
  • Kerfing
  ' Laminating	
• Mechanical and Vapor Plating
• Metallic Fiber Cloth Manufacturing
• Metal Spraying (including Water Curtain)
• Painting-immersion (including Electrophoretic,
 "E-coat")
• Photo Imaging
• Photo Image Developing
• Photoresist Application
• Photoresist Strip
• Phosphor Deposition
• Physical Vapor Deposition
• Plasma Arc Machining
• Plastic Wire Extrusion
• Salt Bath Descaling
• Shot Tower - Lead Shot Manufacturing
• Soldering
• Solder Flux Cleaning
• Solder Fusing
• Solder Masking
• Sputtering
• Stripping (paint)
• Stripping (metallic coating)
• Thermal Infusion
• Ultrasonic Machining
• Vacuum Impregnation
• Vacuum Plating
• Water Shedder
• Wet Air Pollution Control
• Wire Galvanizing Flux
Note: This list is replicated at 40 CFR 438.2(d) with definitions at Appendix C to Part 438.
                                                4-16

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                                                                         4.0 - Industry Description

              EPA also evaluated process wastewater from "Bilge Water" and "Dry
Dock/Stormwater" for the final rule. These two processes generate mainly oily or organic
wastewater but are not included in the final definition of "oily operations" (as defined in 40 CFR
438.2(f)) as these unit operations only occur at facilities EPA decided should not be subject to the
final rule (see 40 CFR 438. l(e)(5)). EPA used the following definitions for "Bilge Water" and
"Dry Dock/Stormwater" for the final rule:

              •      Bilge Water is water that collects in the inner hull  of a ship. When a ship
                    is in a dry dock or similar structure, the bilge water is collected and then
                    treated and disposed of.

              •      Dry Dock/Stormwater.  Maintenance operations performed on a
                    ship/boat in a dry dock that either use process water or are exposed to
                    stormwater.

              The following descriptions are provided to aid the reader in understanding the
described processes and do not supersede regulatory definitions of unit operations in the final
MP&M rule. Moreover, the definitions in this section should not be used to differentiate
between the six "core" metal finishing operations (i.e., Electroplating, Electroless Plating,
Anodizing, Coating (chromating, phosphating, and coloring), Chemical Etching and Milling,  and
Printed Circuit Board Manufacture) and 40 "ancillary" process operations listed at 40 CFR
433.10(a).

4.2.2.1        Description of MP&M Oily Operations

Abrasive Blasting involves removing surface film from a part by using abrasive directed at high
velocity against the part. Abrasive blasting includes bead, grit,  shot, and sand blasting, and may
be performed either dry or with water. 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. In abrasive blasting, the water and
abrasive typically are reused until the particle size diminishes due to impacting and fracture.

Adhesive Bonding involves joining parts using an adhesive material. Typically, an organic
bonding compound is used as the adhesive. This operation usually is dry;  however, aqueous
solutions may be used as bonding agents or to contain residual  organic bonding materials.

Alkaline Cleaning for Oil Removal  is a general term for the application  of an alkaline cleaning
agent to a metal part to remove oil and grease during the manufacture, maintenance, or rebuilding
of a metal product.

This unit operation does not include washing of the  finished products after routine use (as
defined in "Washing (Finished Products)" in this subsection), or applying an alkaline cleaning
                                          4-17

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                                                                         4.0 - Industry Description

agent to remove nonoily contaminants such as dirt and scale (as defined in "Alkaline Treatment
Without Cyanide" in this subsection and "Alkaline Treatment With Cyanide" in Section 4.2.2.2).
Wastewater generated includes spent cleaning solutions and rinse waters.

              •      Alkaline cleaning is performed to remove foreign contaminants from
                     parts. This operation usually is done prior to finishing (e.g.,
                     electroplating).

              •      Emulsion cleaning is an alkaline cleaning operation that uses either
                     complex chemical enzymes or common organic solvents (e.g., kerosene,
                     mineral oil, glycols, and benzene) dispersed in water with the aid of an
                     emulsifying agent. The pH of the solvent usually is between 7 and 9, and,
                     depending on the solvent used, cleaning is performed at temperatures from
                     room temperature to 82°C (180°F). This operation often is used as a
                     replacement for vapor degreasing.

Alkaline Treatment Without Cyanide is a general term used to describe the application of an
alkaline solution not containing cyanide to a metal surface to clean the metal surface or prepare
the metal surface for further surface finishing.

Aqueous Degreasing involves cleaning metal parts using aqueous-based  cleaning chemicals
primarily to remove residual oils and greases from the part.  Residual oils can be from previous
operations (e.g., machine coolants), oil from product use in  a dirty environment, or oil coatings
used to inhibit corrosion. Wastewater generated by this operation includes spent cleaning
solutions and rinse waters.

Assembly/Disassembly involves fitting together previously manufactured or rebuilt parts or
components into a complete metal product or machine or taking a complete metal product or
machine apart. Assembly/disassembly operations are typically dry; however, special
circumstances can require water for cooling or buoyancy. Also,  rinsing may be necessary under
some conditions.

Burnishing involves finish sizing or smooth finishing a part (previously machined or ground) by
displacing, rather than removing, minute surface irregularities with smooth point or line-contact,
fixed or rotating tools. Lubricants or soap solutions can be used to cool the tools used in
burnishing operations. Wastewater generated during burnishing include process solutions and
rinse water.

Calibration is performed to provide reference points for the use of a product. This unit operation
typically is dry, although water may be used in some cases (e.g., pumping water for calibration of
a pump). Water used in this unit operation usually does not  contain additives.

Corrosion Preventive Coating involves applying removable oily or organic solutions to protect
metal surfaces against corrosive environments. Corrosion preventive coatings include, but are not
                                          4-18

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                                                                          4.0 - Industry Description

limited to: petrolatum compounds, oils, hard dry-film compounds, solvent-cutback petroleum-
based compounds, emulsions, water-displacing polar compounds, and fingerprint removers and
neutralizers. Corrosion preventive coating does not include electroplating or chemical conversion
coating operations.

Many corrosion preventive materials also are 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.

Wastewater generated during corrosion preventive coating includes spent process solutions and
rinses. Process solutions are discharged when they become contaminated with impurities or are
depleted of constituents. Corrosion preventive coatings typically do not require an associated
rinse, but parts are sometimes rinsed to remove the coating before further processing.

Electrical Discharge Machining involves removing metals by a rapid spark discharge between
different polarity electrodes, one the part and the other the tool, separated by a small gap. The gap
may be filled with air or a dielectric fluid. This operation is used primarily to cut tool alloys, hard
nonferrous alloys, and other hard-to-machine materials. Most electrical discharge machining
processes are operated dry; however, in some cases, the process uses water and generates
wastewater containing dielectric fluid.

Floor Cleaning (in Process Area) removes dirt, debris, and process solution spills from process
area floors. Floors can be cleaned using wet or dry methods, such as vacuuming, mopping, dry
sweeping, and hose rinsing. Nonprocess area floor cleaning in offices and other similar
nonprocess areas is not included in this unit operation.

Grinding involves removing stock from a part by using abrasive grains held by a rigid or
semirigid binder. Grinding shapes or deburrs the part. The grinding tool usually is a disk (the
basic shape of grinding wheels), but can also be a cylinder, ring, cup, stick, strip, or belt. The
most commonly used abrasives are aluminum oxide, silicon carbide, and diamond. The process
may use a grinding fluid to cool the part and remove debris or metal fines.

Wastewater generated during grinding 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. Rinse waters typically are assimilated
into the working fluid or treated on site.

Heat Treating involves modifying the physical properties of a part by applying controlled
heating and cooling cycles. This operation includes tempering, carburizing, cyaniding, nitriding,
annealing, aging, normalizing,  austenitizing, austempering, siliconizing, martempering,  and
malleablizing. Parts are heated in furnaces or molten salt baths, and then may be cooled by
quenching in aqueous solutions (e.g., brine solutions), neat oils (pure oils with little or no
impurities), or oil/water emulsions. Heat treating typically is a dry operation, but is considered a
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wet operation if aqueous quenching solutions are used. Wastewater includes spent quench water
and rinse water.

Impact Deformation involves applying impact force to a part to permanently deform or shape it.
Impact deformation may include mechanical processes such as hammer forging, shot peening,
peening, coining, high-energy-rate forming, heading, or 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.

These operations typically are dry, but wastewater can be generated from lubricant discharge and
from rinsing operations associated with the operation.

Iron Phosphate Conversion Coating is the process of applying a protective coating on the
surface of a metal using a bath consisting of a phosphoric acid solution containing no metals
(e.g., manganese, nickel, or zinc) or a phosphate salt solution (i.e., sodium or potassium salts of
phosphoric acid solutions) containing no metals (e.g., manganese, nickel, or zinc) other than
sodium or potassium. Any metal concentrations in the bath are from the  substrate.

Machining involves removing stock from  a part (as chips) by forcing a cutting tool against the
part. This includes machining processes such as turning, milling, drilling, boring, tapping,
planing, broaching, sawing, shaving, shearing, threading, reaming, shaping, slotting, hobbing,
and chamfering.  Machining processes use various types of metal-working fluids, the choice of
which depends on the type of machining being performed and the preference of the machine
shop. The fluids can be categorized into four groups: straight oil (neat oils), synthetic,
semisynthetic, and water-soluble oil.

Machining operations generate wastewater from working fluid or rinse water discharge. Metal-
working fluids periodically are discarded because of reduced performance or development of a
rancid odor. After machining, parts are sometimes rinsed to remove coolant and metal chips. The
coolant reservoir is sometimes rinsed, and the rinse water is added to the working fluid.

Painting - Spray or Brush (Including Water Curtains) involves applying an organic coating
to a part. Coatings such as paint, varnish, lacquer, shellac, and plastics are applied by spraying,
brushing, roll coating, lithographing, powder coating, and wiping.

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), and control the introduction of pollutants into the workplace and
environment.
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Polishing involves removing stock from a part using loose or loosely held abrasive grains carried
to the part by a flexible support. Usually, the objective is to achieve a desired surface finish or
appearance rather than to remove a specified amount of stock. Buffing is included in this unit
operation, and usually is 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
typically are dry, although liquid compounds and associated rinses are used in some polishing
processes.

Pressure Deformation involves applying force (other than impact force) to permanently deform
or shape a part. Pressure deformation may include rolling, drawing, bending, embossing, sizing,
extruding, squeezing, spinning, necking, forming,  crimping or flaring.

These operations use natural and synthetic oils, light greases, and pigmented lubricants.
Pigmented lubricants include whiting, lithapone, mica, zinc oxide, molybdenum disulfide,
bentonite, flour, graphite, white lead, and soap-like materials.

Pressure deformation typically is dry, but wastewater is  sometimes generated from the discharge
of lubricants or from rinsing associated with the process.

Solvent Degreasing removes oils and grease from the surface of a part 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 takes place in either the liquid or vapor phase. Solvent vapor degreasing
normally is quicker than solvent liquid degreasing. However, ultrasonic vibration is sometimes
used with liquid solvents to decrease the required immersion time of complex shapes.  Solvent
cleaning often is used as a precleaning operation prior to alkaline cleaning, as a  final cleaning of
precision parts, or as surface preparation for some  painting operations. Solvent degreasing
operations typically are not followed by rinsing, although rinsing is performed in some cases.

Steam Cleaning removes residual dirt, oil, and grease from parts after processing though other
unit operations. Typically, additives are not used in this operation; the hot steam removes the
pollutants. Wastewater is generated when the cleaned parts are rinsed.

Testing (e.g., hydrostatic, dye penetrant, ultrasonic, magnetic flux) involves applying
thermal,  electrical, mechanical, hydraulic, or other energy to determine the suitability or
functionality of a part, assembly, or complete unit. Testing also may include applying surface
penetrant dyes to detect surface imperfections.  Other examples of tests frequently performed
include electrical testing, performance testing, and ultrasonic testing; these tests typically are dry
but may generate wastewater under certain circumstances.  Testing usually is performed to
replicate some aspect of the working environment. Wastewater generated during testing includes
spent process solutions and rinses.
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Thermal Cutting involves cutting, slotting, or piercing a part using an oxy-acetylene oxygen
lance, electric arc cutting tool, or laser. Thermal cutting typically is a dry process, except for the
use of contact cooling waters and rinses.

Tumbling/Barrel Finishing/Mass Finishing/Vibratory Finishing involves polishing or
deburring a part using a rotating or vibrating container and abrasive media or other polishing
materials to achieve a desired surface appearance. 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 (e.g., alkaline detergents). As the barrel rotates, the upper layer of the part slides toward
the lower side of the barrel, causing the abrading or polishing. Similar results can be achieved 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 during 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.

Washing (Finished Products) involves cleaning finished metal products after use or storage
using fresh water or water containing a mild cleaning solution. This unit operation applies only to
the finished products that do not require maintenance or rebuilding.

Welding involves joining two or more pieces of material by applying heat, pressure, or both,
with or without filler material, to produce a metallurgical bond through fusion or recrystallization
across the interface. This includes gas welding, resistance welding, arc welding, cold welding,
electron beam welding, and laser beam welding. Welding typically is a dry process, except for
the occasional use of contact cooling waters or rinses.

Wet Air Pollution Control for Organic Constituents involves using water to remove organic
constituents that are entrained in air streams exhausted from process tanks or production areas.
Most frequently, wet air pollution control devices are used with cleaning and coating processes.
A common type of wet air pollution control is the wet packed scrubber consisting of a spray
chamber that is filled with packing material. Water is continuously sprayed onto the packing and
the air stream is pulled through the packing by a fan. Pollutants in the air stream are absorbed by
the water droplets and the air is released to the atmosphere.  A single scrubber often serves
numerous process tanks.

4.2.2.2        Description of MP&M Metal-bearing Operations

Abrasive Jet Machining includes removing stock material from a part by a high-speed stream  of
abrasive particles carried by a liquid or gas from a nozzle. Abrasive jet machining is used for
deburring, drilling, and cutting thin sections of metal or composite material. Unlike abrasive
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blasting, this process operates at pressures of thousands of pounds per square inch. The liquid
streams typically are alkaline or emulsified oil solutions, although water also can be used.

Acid Pickling Neutralization involves using a dilute alkaline solution to raise the pH of acid
pickling rinse water that remains on the part after pickling. The wastewater from this operation is
the acid pickling neutralization rinse water.

Acid Treatment With Chromium is a general term used to describe any application of an acid
solution containing chromium to a metal surface. Acid cleaning, chemical etching, and pickling
are types of acid treatment.

Chromic acid is used occasionally to clean cast iron, stainless steel, cadmium and aluminum, and
bright dipping of copper and copper alloys. Also, chromic acid solutions can be used for the final
step in acid cleaning phosphate conversion coating systems. Chemical conversion coatings
formulated with chromic acid are defined at "Chromate Conversion Coating (or Chromating)" in
this subsection.

Wastewater generated during acid treatment includes spent solutions and rinse waters. Spent
solutions typically are batch discharged and treated or disposed of off site. Most acid treatment
operations are followed by a water rinse to remove residual acid.

Acid Treatment Without Chromium is a general term used to describe any application of an
acid solution not containing chromium to a metal surface. Acid cleaning, chemical etching, and
pickling are types of acid treatment.

Wastewater generated during acid treatment includes spent solutions and rinse waters. Spent
solutions typically are batch discharged and treated or disposed of off site. Most acid treatment
operations are followed by a water rinse to remove residual acid.

Alcohol Cleaning involves removing dirt and residue material from a part using alcohol.

Alkaline Cleaning Neutralization involves using a dilute acid solution to lower the pH of
alkaline cleaning rinse water that remains on the part after alkaline cleaning. Wastewater from
this operation is the alkaline cleaning neutralization rinse water.

Alkaline Treatment With  Cyanide is the cleaning of a metal surface with an alkaline solution
containing cyanide.

Wastewater generated during alkaline treatment includes spent solutions and rinse waters.
Alkaline treatment solutions become contaminated from the introduction of soils and dissolution
of the base metal. They usually are treated and disposed of on a batch basis. Alkaline treatment
typically is followed by a water rinse that is  discharged to a treatment system.
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Anodizing With Chromium involves producing a protective oxide film on aluminum,
magnesium, or other light metal, usually by passing an electric current through an electrolyte bath
in which the metal is immersed. Anodizing may be followed by a sealant operation.

Chromic acid anodic coatings have a relatively thick boundary layer and are more protective than
are sulfuric acid coatings. For these reasons, chromic acid is sometimes used when the part
cannot be rinsed completely. These oxide coatings provide corrosion protection, decorative
surfaces, a base for painting and other coating processes, and special electrical and mechanical
properties.

Wastewaters generated during anodizing include spent anodizing solutions, sealants, and rinse
waters. 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. Rinse water following
anodizing, coloring, and sealing typically is discharged to a treatment system.

Anodizing Without Chromium involves applying a protective oxide film to aluminum,
magnesium, or other light metal, usually by passing an electric current through an electrolyte bath
in which the metal is immersed. Phosphoric acid, sulfuric acid, and boric acid are used in
anodizing. Anodizing also may include sealant baths. These oxide coatings provide corrosion
protection,  decorative surfaces, a base for painting and other coating processes, and special
electrical and mechanical properties.

Wastewater generated during anodizing includes spent anodizing solutions, sealants, and rinse
waters. 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. Rinse water following
anodizing, coloring, and sealing steps typically is discharged to a treatment systems.

Carbon Black Deposition involves coating the inside of printed circuit board holes by dipping
the circuit board into a tank that contains carbon black and potassium hydroxide.  After excess
solution dips from the circuit boards, they are heated to allow the carbon black to adhere to the
board.

Catalyst Acid Pre-Dip uses rinse water to remove residual solution from a part after the part is
processed in an acid bath. The wastewater generated in this unit operation is the rinse water.

Chemical Conversion Coating without Chromium is the process of applying a protective
coating on the surface of a metal without using chromium. Such  coatings are applied through
phosphate conversion (except for "Iron Phosphate Conversion Coating," see  section 4.2.2.1),
metal coloring, or passivation. Coatings are applied to a base metal or previously deposited metal
to increase  corrosion protection and lubricity, prepare the surface for additional coatings, or
formulate a special surface appearance. This unit process includes sealant operations that use
additives other than chromium.
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              •      In 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; or to provide a suitable base for corrosion-resistant oils or
                    waxes. Phosphate conversion coatings are formed by immersing a metal
                    part in a dilute solution of phosphoric acid, phosphate salts, and other
                    reagents.

              •      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.

              •      Passivation forms a protective coating on metals, particularly stainless
                    steel, by immersing the part 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.

Wastewater generated during chemical conversion coating includes spent solutions and  rinses
(i.e., both the chemical conversion coating solutions and post-treatment sealant solutions). These
solutions commonly are discharged to a treatment system when contaminated with the base metal
or other impurities. Rinsing normally follows each process step, except when a sealant dries on
the part surface.

Chemical Milling (or Chemical Machining) involves removing metal from a part by controlled
chemical attack, or etching, to produce desired shapes and dimensions. In chemical machining, a
masking agent typically is applied to cover a portion of the part's surface; the exposed
(unmasked) surface is then treated with the chemical machining solution.

Wastewater generated during chemical machining includes spent solutions and rinses. Process
solutions typically are discharged after becoming contaminated with the base metal. Rinsing
normally follows chemical machining.

Chromate Conversion Coating (or Chromating) involves forming a conversion coating
(protective coating) on a metal by immersing or spraying the metal with a hexavalent chromium
compound solution to produce a hexavalent or trivalent chromium compound coating. This also
is known as chromate treatment, and is most often applied to aluminum, zinc, cadmium or
magnesium surfaces. Sealant operations using chromium also are included in this unit operation.
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Chromate solutions include two types: (1) those that deposit substantial chromate films on the
substrate metal and are complete treatments themselves, and (2) those that seal or supplement
oxide, phosphate, or other types of protective coatings.

Wastewater generated during chromate conversion coating includes spent process solutions (i.e.,
both the chromate conversion coating solutions and post-treatment sealant solutions) and rinses.
These solutions typically are discharged to a treatment system 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 for sealants that dry on
the surface of the part.

Chromium Drag-out Destruction is a unit operation performed following chromium-bearing
operations to reduce hexavalent chromium that is "dragged out" of the process bath. Parts are
dipped in a solution of a chromium-reducing chemical (e.g., sodium metabisulfite) to prevent the
hexavalent chromium from  contaminating subsequent process baths.  This operation typically is
performed in a stagnant drag-out rinse tank that contains concentrated chromium-bearing
wastewater.

Cyanide Drag-out Destruction involves dipping the part in a cyanide oxidation solution (e.g.,
sodium hypochloride) to prevent cyanide that is "dragged out" of a process bath from
contaminating subsequent process baths. This operation typically is performed in a stagnant drag-
out rinse tank.

Cyaniding Rinse is generated during cyaniding hardening of a part. The part is heated in a
molten salt solution containing cyanide. Wastewater is generated when excess cyanide salt
solution is removed from the part in rinse water.

Electrochemical Machining is a process in which the part becomes the anode and a shaped
cathode is the cutting tool. By pumping electrolyte between the electrodes and applying a current,
metal is rapidly but selectively dissolved from the part. Wastewater generated during
electrochemical machining includes spent electrolytes and rinses.

Electroless Catalyst Solution involves adding a catalyst just prior to an electroless plating
operation to accelerate the plating operation.

Electroless Plating involves applying a metallic coating to a part using a chemical reduction
process in the presence of a catalysis. An electric current is not used in this operations. The metal
to be plated onto a part typically is held in solution at high concentrations using a chelating agent.
This plates all areas of the part to a uniform thickness  regardless of the configuration of the part.
Also, an electroless-plated surface is dense and virtually nonporous. Copper and nickel
electroless plating operations are the most common.
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Sealant operations (i.e., other than hot water dips) following electroless plating are considered
separate unit operations if they include any additives.

Wastewater generated during electroless plating includes spent process solutions and rinses. The
wastewater contains chelated metals, which require separate preliminary treatment to break the
metal chelates prior to conventional chemical precipitation. Rinsing follows most electroless
plating processes to remove residual plating solution and prevent contamination of subsequent
process baths.

Electrolytic Cleaning involves removing soil, scale, or surface oxides from a part by
electrolysis. The part is one of the electrodes and the electrolyte is usually alkaline. Electrolytic
alkaline cleaning and electrolytic acid cleaning are the two types of electrolytic cleaning.

              •      Electrolytic alkaline cleaning produces a cleaner surface than do
                     nonelectrolytic methods of alkaline cleaning. This operation 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.

              •      Electrolytic acid cleaning sometimes is used as a final cleaning before
                     electroplating. Sulfuric acid is most frequently used as the electrolyte. As
                     with electrolytic alkaline cleaning, the mechanical scrubbing effect from
                     the evolution of gas enhances the effectiveness of the process.

Wastewater generated during electrolytic cleaning includes spent process solutions and rinses.
Electrolytic cleaning solutions become contaminated during use due to the dissolution of the base
metal and the introduction of pollutants.  The solutions typically are batch discharged for
treatment or disposal after they weaken. Rinsing following electrolytic cleaning removes residual
cleaner to prevent contamination of subsequent process baths.

Electroplating with Chromium involves producing a chromium metal coating on a surface by
electrodeposition. Electroplating provides corrosion protection, wear or erosion resistance,
lubricity, 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. Metal salts or oxides typically are added to replenish the
solutions. Chromium trioxide often is 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 to dissolve anodes, and miscellaneous
ingredients that modify the process to attain specific properties. Sealant operations performed
after this operation  are considered separate unit operations if they include any additives (i.e.,
other than hot water dips).
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Wastewater generated during electroplating includes spent process solutions and rinses.
Electroplating solutions occasionally become contaminated during use due to the base metal
dissolving and the introduction of other pollutants, diminishing the effectiveness of the
electroplating solutions.  Spent concentrated solutions typically are treated to remove pollutants
and reused, processed in a wastewater treatment system, or disposed of off site. Rinse waters,
including some drag-out rinse tank solutions, typically are treated on site.

Electroplating with Cyanide involves producing metal coatings on a surface by
electrodeposition using cyanide. Electroplating provides corrosion protection, wear or erosion
resistance, 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 typically  are replenished by
dissolving metal from anodes contained in inert wire or metal baskets. Sealant operations
performed after this operation are considered separate unit operations if they include any
additives (i.e., any sealant operations other than hot water dips).

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 to
control pH, catalysts to assist in deposition, chemical aids to dissolve anodes, and miscellaneous
ingredients that modify the process to attain specific properties. Cyanide, usually in the form of
sodium or potassium cyanide,  frequently is used as a complexing agent for zinc, cadmium,
copper, and  precious metal baths.

Wastewater generated during electroplating includes spent process solutions and rinses.
Electroplating solutions occasionally become contaminated during use due to dissolution of the
base metal and the introduction of other pollutants, diminishing the performance of the
electroplating solutions. Spent concentrated solutions typically are treated to remove pollutants
and reused, processed in a wastewater treatment system, or disposed of off site. Rinse waters,
including some drag-out rinse tank solutions, typically are treated on site.

Electroplating without Chromium or Cyanide involves the production of metal coatings on a
surface by electrodeposition, without using chromium or cyanide. Commonly electroplated
metals include nickel, copper,  tin/lead, gold, and zinc. Electroplating provides corrosion
protection, wear or erosion resistance, lubricity, 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 typically  are replenished by
dissolving metal from anodes contained in inert wire or metal baskets. Sealant operations
performed after this operation are considered separate unit operations if they include any
additives (i.e., any sealant operations other than hot water dips).

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 to
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control pH, catalysts to assist in deposition, chemical aids to dissolve anodes, and miscellaneous
ingredients that modify the process to attain specific properties.

Wastewater generated during electroplating without chromium or cyanide includes spent process
solutions and rinses. Electroplating solutions occasionally become contaminated during use due
to dissolution of the base metal and the introduction of other pollutants, diminishing the
effectiveness of the electroplating solutions. Spent concentrated solutions typically are treated for
pollutant removal and reused, processed in a wastewater treatment system, or disposed  of off site.
Rinse waters, including some drag-out rinse tank solutions, typically are treated on site.

Electropolishing involves producing a highly polished surface on a part using reversed
electrodeposition in which the  anode (part) releases some metal ions into the electrolyte to reduce
surface roughness. When current is applied, a polarized film forms on the metal surface, through
which metal ions  diffuse. In this operation, areas of surface roughness on parts serve as high-
current density areas and are dissolved at rates greater than the rates for smoother portions of the
metal surface.

Metals are electropolished to improve appearance, reflectivity, and corrosion resistance. Base
metals processed by electropolishing include aluminum, copper, zinc, low-alloy steel, and
stainless steel. Common electrolytes include sodium hydroxide and combinations of sulfuric
acid, phosphoric acid, and chromic acid.

Wastewater generated during electropolishing includes spent process solutions and rinses.
Eventually, the concentration of dissolved metals increases to  the point where the process
becomes ineffective. Typically, a portion of the bath is decanted and either fresh chemicals are
added or the entire solution is discharged to treatment and replaced with fresh chemicals. Rinsing
can involve several steps and can include hot immersion or spray rinses.

Galvanizing/Hot Dip Coating involves using various processes to coat an iron or steel surface
with zinc. In hot dipping, a base metal is coated by dipping it into a tank that contains a molten
metal.

Hot Dip Coating involves applying a metal coating (usually zinc) to the surface of a part by
dipping the part in a molten metal bath. Wastewater is generated in this operation when residual
metal coating solution is removed from the part in rinse water.

Kerfing uses a tool to remove  small amounts of metal from a  product surface. Water and
synthetic coolants may be used to lubricate the area between the tool and the metal, to maintain
the temperature of the cutting tool, and to remove metal fines from the surface of the part.  This
operation  generates oily wastewater that contains metal fines and dust.

Laminating involves applying a material to a substrate using heat and pressure.
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 Mechanical and Vapor Plating involves applying a metallic coating to a part. For mechanical
 plating, the part is rotated in a drum containing a water-based solution, glass beads, and metal
 powder. In vapor plating, a metallic coating is applied by atomizing the metal and applying an
 electric charge to the part, which causes the atomized (vapor phase) metal to adhere to the part.

 Wastewater generated in this operation includes spent solutions from the process bath and rinse
 water. Typically, the wastewater contains high concentrations of the applied metal.

 Metallic Fiber Cloth Manufacturing involves weaving thin metallic fibers to create a mesh
 cloth.

 Metal Spraying (Including Water Curtain) involves applying a metallic coating to a part by
 projecting molten or semimolten metal particles onto a substrate. Coatings can be sprayed from
 rod or wire stock or from powdered material. The process involves feeding the material (e.g.,
 wire) into a flame where it is melted. The molten stock then is stripped from the end of the wire
 and atomized by a high-velocity stream of compressed air or other gas that propels the material
 onto a prepared substrate or part.

 Metal spraying coatings are used in a wide range of special applications, including: 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 that 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 discharged periodically. Metal spraying typically is not followed by rinsing.

Painting-Immersion (Including Electrophoretic, "E-coat") involves applying an organic
coating to a part using processes such autophoretic and electrophoretic painting.

              •      Autophoretic Painting involves applying an organic paint film by
                     electrophoresis when a part is immersed in a suitable aqueous bath.

              •      Electrophoretic Painting is coating a part by making it either anodic or
                     cathodic in a bath that is generally an aqueous emulsion of the organic
                     coating material.

              •      Other Immersion  Painting includes all other types of immersion painting
                     such as dip painting.

Water is used in immersion paint operations as a carrier for paint particles and to rinse the part.
Aqueous painting solutions and rinses typically are treated through an ultrafiltration  system. The
concentrate is returned to the painting solution, and the permeate is reused as rinse water. Sites
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typically discharge a bleed stream to treatment. The painting solution and rinses are batch
discharged periodically to treatment.

Photo Imaging is the process of exposing a photoresist-laden printed wiring board to light to
impact the circuitry design to the board. Water is not used in this operation.

Photo Image Developing is an operation in which a water-based solution is used to develop the
exposed circuitry in a photoresist-laden printed wiring board. Wastewater generated in this
operation includes  spent process solution and rinse water.

Photoresist Application is an operation that uses heat and pressure to apply a photoresist coating
to a printed wiring  board. Water is not used in this operation.

Photoresist Strip involves removing organic photoresist material from a printed wiring board
using an acid solution.

Phosphor Deposition is the application of a phosphorescent coating to a part. Wastewater
generated in this unit operation includes water used to keep the parts clean  and wet while the
coating is applied,  and rinse water used to remove excess phosphorescent coating from the part.

Physical Vapor Deposition involves physically removing a material from  a source through
evaporation or sputtering, using the energy of the vapor particles in a vacuum or partial vacuum to
transport the removed material, and condensing the  removed material as a film onto the  surface of
a part or other substrate.

Plasma Arc Machining involves removing material or shaping a part by a high-velocity jet of
high-temperature, ionized gas. A gas (nitrogen, argon, or hydrogen) is passed through an electric
arc, causing the gas to become ionized, and heated to temperatures exceeding 16,650°C
(30,000°F). The relatively narrow plasma jet melts and displaces the material in its path. Because
plasma arc 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.

Although plasma arc machining typically is a dry process, water is used for water injection plasma
arc torches. In these cases, a constricted swirling flow of water surrounds the cutting arc. This
operation also may be performed immersed in a water bath. In both cases, water is used to
stabilize the arc, to cool the part, and to contain smoke and fumes.

Plastic Wire Extrusion involves applying a plastic material to a metal wire through an extrusion
process.

Salt Bath Descaling involves removing surface oxides or scale from a part by immersing the part
in a molten salt bath or hot  salt solution. Salt bath descaling solutions can contain molten salts,
                                           4-31

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                                                                          4.0 - Industry Description

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 steel and other corrosion-
resistant alloys. In this process, the part typically is immersed in the molten salt, quenched with
water, and then dipped in acid. Oxidizing, reducing, or electrolytic  salt baths can be used
depending on the oxide to be removed. Wastewater generated during salt bath descaling includes
spent process solutions, quenches, and rinses.

Shot Tower - Lead Shot Manufacturing involves dropping molten lead from a platform on the
top of a tower through a sieve-like device and into a vat of cold water.

Soldering involves joining metals by inserting a thin (capillary thickness) layer of nonferrous
filler metal into the space between them. Bonding results from the intimate contact produced by
the metallic bond formed between the substrate metal and the solder alloy.  The term soldering is
used where the melting temperature of the filler is below  425°C (800°F). Some soldering
operations use a solder flux, which is an aqueous or nonaqueous material used to dissolve,
remove, or prevent the formation of surface oxides on the part.

Except for the use of aqueous fluxes,  soldering typically is 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.

Solder Flux Cleaning involves removing residual solder flux from a printed circuit board using
either an alkaline or alcohol cleaning  solution.

Solder Fusing involves coating a tin-lead plated circuit board with a solder flux and then passing
the board through a hot oil. The hot oil fuses the tin-lead  to the board and creates a solder-like
finish on the board.

Solder Masking involves applying a resistive coating to  certain areas of a  circuit board to protect
the areas during subsequent processing.

Sputtering is a vacuum evaporation process in which portions of a coating material are physically
removed from a substrate and deposited a thin film onto a different substrate.

Stripping (Paint) involves removing a paint (or other organic) coating from a metal basis
material. Stripping commonly is performed as part of the manufacturing process to recover parts
that have been improperly coated or as part of maintenance and rebuilding  to restore parts to a
usable condition.

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 (as defined in "Abrasive Blasting" in
                                           4-32

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                                                                          4.0 - Industry Description

Section 4.2.2.1). Chemical paint strippers include alkali solutions, acid solutions, and solvents
(e.g., methylene chloride).

Wastewater generated during organic coating stripping includes process solutions (limited mostly
to chemical paint strippers and rinses).

Stripping (Metallic Coating) involves removing a metallic coating from a metal basis material.
Stripping is commonly part of the manufacturing process to recover parts that have been
improperly coated or as 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) also are used. Chemical stripping frequently is performed as an
aqueous electrolytic process.

Wastewater generated during metallic coating stripping includes process solutions and rinses.
Stripping solutions become contaminated from dissolution of the base metal. Typically, the  entire
solution is discharged to treatment. Rinsing is used to remove the corrosive film remaining on the
parts.

Thermal Infusion uses heat to infuse metal powder or dust onto the surface of a part. Typically,
thermal infusion is a dry operation. In some cases, however, water may be used to remove excess
metal powder, metal dust, or molten metal.

Ultrasonic Machining involves forcing an abrasive liquid between a vibrating tool and a part.
Particles in the abrasive liquid strike the part, removing any microscopic flakes on the part.

Vacuum Impregnation is used to reduce the porosity of the part. A filler material (usually
organic) is  applied to the  surface of the part and polymerized under pressure and heat. Wastewater
is generated in this unit operation when rinse water is used to remove residual organic coating
from the part.

Vacuum Plating involves applying a thin layer of metal oxide onto a part using molten metal in a
vacuum chamber.

Water Shedder involves applying a dilute water-based chemical compound to a part to accelerate
drying. This operation typically is used to prevent a part from streaking when excess water
remains on the part.

Wet Air Pollution Control involves using water to remove chemicals, fumes, or dusts that are
entrained in air streams exhausted from process tanks or production areas. Most  frequently,  wet
air pollution control devices are used with electroplating, cleaning, and coating processes. A
common type of wet air pollution control is the wet packed scrubber consisting of a spray
chamber that is filled with packing material. Water is continuously sprayed onto the packing and
the air stream is pulled through the packing by a fan.  Pollutants in the air stream are absorbed by
                                           4-33

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                                                                         4.0 - Industry Description

the water droplets and the air is released to the atmosphere. A single scrubber often serves
numerous process tanks; however, the air streams typically are segregated by source into
chromium,  cyanide, and acid/alkaline sources. Wet air pollution control can be divided into
several suboperations, including:

              •       Wet Air Pollution Control for Acid Alkaline Baths;
              •       Wet Air Pollution Control for Cyanide Baths;
              •       Wet Air Pollution Control for Chromium-Bearing Baths; and
              •       Wet Air Pollution Control for Fumes and Dusts.

Wire Galvanizing Flux involves using flux to remove rust and oxide from the surface of steel
wire prior to galvanizing. This provides long-term corrosion protection for the steel wire.

4.2.3         Metals Processed

              MP&M facilities perform proposed MP&M operations on a variety of metals.
EPA identified 29 different metals processed at MP&M facilities from survey results. Of these,
iron, aluminum, and copper are the metals most frequently processed. Nickel, tin, lead, gold, and
zinc frequently are used in electroplating operations.

              Many MP&M facilities process more than one metal.  Figure 4-7 shows the
percentage  of wastewater-discharging MP&M facilities by number of metals processed. As
shown in Figure 4-7, 65 percent of the wastewater-discharging MP&M facilities that provided
metal use information process more than one metal.

4.2.4         Estimated Annual Wastewater Discharge

              Process wastewater is generated in many of the proposed MP&M operations listed
in Section 4.2.2.  Some operations may be performed with or without water (wet or dry)
depending on the purpose of the operation, raw materials used, and final product use. For
example, some machining operations (e.g., drilling) are performed without a coolant, while other
machining operations (e.g., milling) require a coolant. Process wastewater may be recirculated,
recycled or reused as described in Section  4.1.4; however, process wastewater generally is
discharged  to a treatment system or disposed of through other means (e.g., transfer to CWT).

              Based on survey results, the most commonly performed wet proposed MP&M
operations are floor cleaning and acid treatment.  Survey results also  show the most commonly
performed proposed MP&M operations do not generate the largest volumes of wastewater. Of the
volume of wastewater discharged, 79 percent is generated from rinses, with chemical conversion
coating rinsing, acid treatment rinsing, and alkaline treatment rinsing generating the highest
volume of wastewater. Table 4-5 lists the  proposed MP&M operations and presents the estimated
number of MP&M facilities that discharge wastewater generated in each proposed MP&M
operation and the estimated annual discharge for the proposed MP&M operation. Note that
MP&M facilities typically conduct more than one proposed MP&M operation.
                                          4-34

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                                                                       4.0 - Industry Description
            Five or More Metal Types
                    12%
     Four Metal Types
         7%
   Three M etal Types
        22%
                                                                     One M etal Type
                                                                          36%
                                            Two M etal Types
                                                 24%
  Source: MP&M Survey Database.
  Note:   Although there are 44,000 wastewater-discharging MP&M facilities only 15,470 are
          represented in the above pie chart. The 1996 short and municipality surveys did not
          request metal use information.  Additionally, several 1989 and 1996 long survey recipients
          did not provide this information.

Figure 4-7. Percentage of Wastewater-Discharging  MP&M facilities
                     by Number of Metal Processed
                                    4-35

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                                                        4.0 - Industry Description
                             Table 4-5

Estimated Number of MP&M Facilities Discharging Process Wastewater
   by Proposed MP&M Operation and Estimated Annual Discharge3
                for Each Proposed MP&M Operation
Survey Unit
Operation
Number
1
1R.
2
3
3R.
4
4R.
5
5R.
6
6R.
7
7R.
8
8R.
9
9R.
10
10R.
11
11R.
12
12R.
13
13R.
14
Unit Operation
Abrasive Blasting
Abrasive Blasting Rinse
Abrasive Jet Machining
Acid Treatment With Chromium
Acid Treatment With Chromium Rinse
Acid Treatment Without Chromium
Acid Treatment Without Chromium
Rinse
Alkaline Cleaning for Oil Removal
Alkaline Cleaning for Oil Removal
Rinse
Alkaline Treatment With Cyanide
Alkaline Treatment With Cyanide
Rinse
Alkaline Treatment Without Cyanide
Alkaline Treatment Without Cyanide
Rinse
Anodizing With Chromium
Anodizing With Chromium Rinse
Anodizing Without Chromium
Anodizing Without Chromium Rinse
Aqueous Degreasing
Aqueous Degreasing Rinse
Assembly/Disassembly
Assembly /Disassembly Rinse
Barrel Finishing
Barrel Finishing Rinse
Burnishing
Burnishing Rinse
Chemical Conversion Coating Without
Chromium
Estimated Number of MP&M
Facilities Discharging
Wastewater from Unit
Operation
1,140
2,714
1,802
789
1,139
21,518
25,886
15,194
10,918
447
529
16,200
12,937
275
358
1,090
1,587
41,220
28,923
2,031
2,189
14,632
6,694
4,920
2,881
9,357
Estimated Annual
Discharge1"
(gpy)
38,136,192
294,364,698
32,882,557
4,119,176
514,116,041
307,274,559
9,877,473,513
1,017,415,369
7,007,305,341
4,260,538
43,781,206
276,426,070
4,782,461,104
271,552
145,962,877
5,430,253
1,303,183,805
669,348,451
517,175,686
18,107,602
796,489
640,037,840
539,294,744
132,891,318
326,955,097
564,137,211
                               4-36

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                                       4.0 - Industry Description
Table 4-5 (Continued)
Survey Unit
Operation
Number
14R.
15
15R.
16
16R.
17
17R.
18
18R.
19
19R.
20
20R.
21
21R.
22
22R.
23
23R.
24
24R.
25
25R.
26
26R.
27
27R.
28
28R.
29
29R.
30
Unit Operation
Chemical Conversion Coating Without
Chromium Rinse
Chemical Milling
Chemical Milling Rinse
Chromate Conversion Coating
Chromate Conversion Coating Rinse
Corrosion Preventive Coating
Corrosion Preventive Coating Rinse
Electrical Discharge Machining
Electrical Discharge Machining Rinse
Electrochemical Machining
Electrochemical Machining Rinse
Electroless Plating
Electroless Plating Rinse
Electrolytic Cleaning
Electrolytic Cleaning Rinse
Electroplating With Chromium
Electroplating With Chromium Rinse
Electroplating With Cyanide
Electroplating With Cyanide Rinse
Electroplating Without Chromium or
Cyanide
Electroplating Without Chromium or
Cyanide Rinse
Electropolishing
Electropolishing Rinse
Floor Cleaning
Floor Cleaning Rinse
Grinding
Grinding Rinse
Heat Treating
Heat Treating Rinse
Impact Deformation
Impact Deformation Rinse
Machining
Estimated Number of MP&M
Facilities Discharging
Wastewater from Unit
Operation
11,582
1,466
2,323
5,071
5,980
2,262
1,015
1,323
559
294
258
2,583
3,664
5,280
6,886
1,019
1,937
1,958
8,885
4,558
13,644
442
458
49,002
3,580
8,738
263
1,609
1,315
404
148
16,935
Estimated Annual
Dischargeb
(gpy)
6,042,069,830
41,355,172
645,522,600
54,795,746
1,707,025,516
41,326,563
287,465,378
934,885
3,368,479
329,427,414
34,587,020
18,034,222
565,437,766
33,756,614
1,501,249,740
37,242,632
678,282,897
38,162,499
686,691,868
92,968,816
3,778,033,165
633,484
70,178,477
797,062,121
45,391,545
169,740,183
72,465,147
156,660,147
2,186,067,713
40,582,591
8,237,308
585,628,906
          4-37

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                                       4.0 - Industry Description
Table 4-5 (Continued)
Survey Unit
Operation
Number
30R.
31
32
32R.
33
33R.
34
35
35R.
36
36R.
37
37R.
38
38R.
39
39R.
40
40R.
41
41R.
42
42R.
43
43R.
44
44R.
45
45R.
46AA
46CN
46CR
Unit Operation
Machining Rinse
Metal Spraying
Painting - Spray or Brush
Painting - Spray or Brush Rinse
Painting - Immersion
Painting - Immersion Rinse
Plasma Arc Machining
Polishing
Polishing Rinse
Pressure Deformation
Pressure Deformation Rinse
Salt Bath Descaling
Salt Bath Descaling Rinse
Soldering/Brazing
Soldering/Brazing Rinse
Solvent Degreasing0
Solvent Degreasing Rinse
Stripping (paint)
Stripping (paint) Rinse
Stripping (metallic coating)
Stripping (metallic coating) Rinse
Testing
Testing Rinse
Thermal Cutting
Thermal Cutting Rinse
Washing Finished Products
Washing Finished Products Rinse
Welding
Welding Rinse
Wet Air Pollution Control for Acid
Alkaline Baths
Wet Air Pollution Control for Cyanide
Baths
Wet Air Pollution Control for
Chromium-Bearing Baths
Estimated Number of MP&M
Facilities Discharging
Wastewater from Unit
Operation
683
91
2,303
688
450
404
547
1,111
2,745
520
249
99
111
1,258
4,905
2,288
824
1,730
2,720
2,929
3,867
5,947
1,093
228
64
17,276
5,378
1,003
360
2,726
189
942
Estimated Annual
Dischargeb
(gpy)
149,922,705
866,823,774
3,009,847,635
726,589,166
164,139,746
190,487,578
10,728,876
113,097,868
567,887,844
241,040,874
783,831,607
62,703
53,938,360
425,688,291
231,488,012
8,128,901
108,089,561
68,326,631
295,059,493
5,855,277
943,853,805
3,713,880,058
46,615,860
35,395,401
2,940,934
1,975,525,613
651,385,578
1,177,301,469
44,297,886
1,335,631,480
43,321,771
234,814,961
          4-38

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                                       4.0 - Industry Description
Table 4-5 (Continued)
Survey Unit
Operation
Number
46FD
46OR
50
50R.
51
51R.
54R.
56
56R.
57
57R.
58
58R.
59
59R.
62
62R.
63
63R.
65
65R.
66
66R.
70
71
72
73R.
74
74R.
76
78
78R.
80
Unit Operation
Wet Air Pollution Control for Fumes
and Dusts
Wet Air Pollution Control for Organic
Constituents
Carbon Black Deposition
Carbon Black Deposition Rinse
Bilge Water
Bilge Water Rinse
Galvanizing/Hot Dip Coating Rinse
Mechanical Plating
Mechanical Plating Rinse
Photo Image Developing
Photo Image Developing Rinse
Photo Imaging
Photo Imaging Rinse
Photoresist Applications
Photoresist Applications Rinse
Solder Flux Cleaning
Solder Flux Cleaning Rinse
Solder Fusing
Solder Fusing Rinse
Steam Cleaning
Steam Cleaning Rinse
Vacuum Impregnation
Vacuum Impregnation Rinse
Kerfing
Adhesive Bonding
Calibration
Cyanide Rinsing Rinse
Hot Dip Coating
Hot Dip Coating Rinse
Thermal Infusion
Phosphor Deposition
Phosphor Deposition Rinse
Chromium Drag-out Reduction
Estimated Number of MP&M
Facilities Discharging
Wastewater from Unit
Operation
657
347
20
43
11
8
69
246
240
1,456
1,531
9
9
15
17
99
461
27
280
26
16
8
98
30
186
55
22
9
75
62
11
11
8
Estimated Annual
Dischargeb
(gpy)
30,596,886
19,613,181
31,848
2,377,389
69,949,548
304,839
225,928,671
27,717,634
202,002,940
430,595,569
603,943,807
27,900
497,022
7,157
180,161
1,694,799
214,927,721
5,739,846
55,114,403
18,130,100
15,851,628
649,893
10,144,137
7,429,800
525,950
2,467
33,490
692
28,135,640
138,939
4,283
42,826
857,994
          4-39

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                                                                                      4.0 - Industry Description
                                      Table 4-5 (Continued)
Survey Unit
Operation
Number
83
83R.
87
87R.
88
88R.
90
90R.
Unit Operation
Acid Pickling Neutralization
Acid Pickling Neutralization Rinse
Tin Catalyst
Tin Catalyst Rinse
Catalyst Acid Pre-Dip
Catalyst Acid Pre-Dip Rinse
Photoresist Strip
Photoresist Strip Rinse
Estimated Number of MP&M
Facilities Discharging
Wastewater from Unit
Operation
8
16
385
468
961
1,108
439
732
Estimated Annual
Dischargeb
(gpy)
22,761
22,497,118
295,415
102,883,125
680,949
64,173,379
8,039,179
312,703,073
Source: MP&M Survey Database.
aEPA used MP&M survey information to generate the estimated facility counts and estimated annual discharge.
bThese totals do not include facilities generating process wastewater that is contract hauled off site or not discharged.
°Solvent degreasing operations that use process water are included under alkaline treatment (see unit operation 5).
                                                  4-40

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                                                                         4.0 - Industry Description

4.3           Trends in the Industry

              To develop the MP&M rule, EPA collected data from the MP&M industry for over
10 years, including detailed information from surveys in 1990, 1996, and 1997.  Survey data and
results of industry site visits and sampling episodes showed numerous changes in the industry
between  1990 and 1996. Survey data indicate a greater than 30-percent industry increase in the
use of wastewater treatment systems between 1990 and 1996. Many facilities also have begun to
implement advanced treatment systems that include ultrafiltration for increased organic pollutant
removal and microfiltration units to improve clarification. The MP&M survey database indicates
that in 1990, 260 of the MP&M facilities with wastewater treatment in place were using
membrane filtration.  By 1996, that number increased to 700. In addition, facilities are moving
toward greater implementation of pollution prevention and water reduction, including progression
to zero discharge when possible. Fifty-three percent currently have in-process pollution
prevention or water use reduction practices in place, and over 27 percent of discharging facilities
report having wet unit operations with zero discharge.  Improvements in treatment controls are
allowing for more automated process controls, which leads to more consistent wastewater
treatment. Advances in wastewater treatment chemicals also result in higher treatment
efficiencies.

4.4           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.            U.S. Environmental Protection Agency. Development Document for Effluent
              Limitations Guidelines and Standards for the  Metal Finishing Point Source
              Category. 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.
                                          4-41

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                                                                    5.0- Wastewater Characteristics

5.0          WASTEWATER CHARACTERISTICS

             This section summarizes the characteristics of wastewater generated by oily
operations (as defined in Section 1.0) and discharged to wastewater treatment systems at MP&M
facilities. In general, the MP&M industry generates oil- and organic pollutant-bearing
wastewater. This wastewater exhibits high concentrations of oil and concentrations of organic
pollutants. Oil-bearing wastewater is classified as containing either free (floating) oils or
oil/water emulsions. These wastewaters may also contain incidental levels of metals most often
in the suspended or paniculate phase.

             Analytical data from the MP&M sampling program, including data obtained from
sanitation districts, MP&M facilities, and MP&M industry trade associations, are in the sampling
episode reports located in Sections 5.2 and 15.3 of the rulemaking record. As part of the MP&M
rulemaking, EPA also evaluated the following wastewaters: (1) hexavalent chromium-bearing
wastewater; (2) cyanide-bearing wastewater; (3) chelated metal-bearing wastewater; and (4)
metal-bearing wastewater. These additional analyses are presented in Appendix C.

             This section summarizes analytical data obtained during the MP&M regulatory
development process for oily operations and influents to the wastewater treatment systems.
These subsections present the number of samples analyzed, the number of times each pollutant
was detected, and the minimum, maximum, mean, and median pollutant concentrations. Section
5.1 discusses the oily operations that generate oil-bearing and organic pollutant-bearing
wastewater and presents pollutant concentration data for the process waters and rinse waters for
those oily operations. Section 5.2 characterizes the influent to oily wastewater treatment
systems.

5.1          Process Water and Rinse Water

             Table 5-1 lists the oily operations that generate oil-bearing and organic pollutant-
bearing wastewater and presents the number of process water and rinse water samples collected
for each operation during EPA's sampling program. Section 4.0 describes these operations in
detail.

             MP&M facilities usually use oil/water emulsions as coolants and lubricants in
machining, grinding, and deformation operations.  These facilities also perform alkaline cleaning
operations to remove oil and grease from parts. Table 5-2 summarizes the pollutant
concentration data collected during the MP&M sampling program for process water from oily
operations that generate oil-bearing wastewater. Table 5-3 summarizes similar data for the
associated rinse waters. The maximum concentration of oil and grease (measured as hexane
extractable material  (HEM)) in the process water samples was 390,000 mg/L (from an alkaline
cleaning bath), while the maximum concentration of oil and grease in the rinse water samples
was 9,195 mg/L.
                                          5-1

-------
                                                                       5.0- Wastewater Characteristics
                                        Table 5-1
   Number of Process Water and Rinse Water Samples For Oily Operations
Unit Operation
Abrasive Blasting
Adhesive Bonding
Alkaline Cleaning for Oil Removal
Alkaline Treatment without Cyanide
Aqueous Degreasing
Corrosion Preventive Coating
Electrical Discharge Machining
Floor Cleaning (In Process Area)
Grinding
Heat Treating
Impact Deformation
Machining
Painting-spray or Brush (Including Water Curtains)
Steam Cleaning
Testing (e.g., Hydrostatic, Dye Penetrant, Ultrasonic, Magnetic Flux)
Thermal Cutting
Tumbling/Barrel Finishing/Mass Finishing/Vibratory Finishing
Washing (Finished Products)
Welding
Wet Air Pollution Control for Organic Constituents
No. of Process
Water Samples3
o
J
0
34
18
11
8
1
6
19
o
J
1
14
6
8
8
2
9
4
0
Ob
No. of Rinse Water
Samples3
o
J
0
42
32
6
4
0
0
0
7
0
0
0
0
o
J
0
4
o
J
1
ob
Source: MP&M Sampling Program.
aOily operations for which no samples were collected are rarely performed or were not observed at MP&M facilities.
bData were transferred for this operation.
NA - Not applicable; unit operation has no associated rinse.
                                            5-2

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                                                       5.0- Wastewater Characteristics
                            Table 5-2
Process Water Pollutant Concentration Data for Oily Operations
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Organic Priority Pollutants
1,1,1 -Trichloroethane
1 , 1 -Dichloroethane
1 , 1 -Dichloroethene
2,4-Dimethylphenol
2,4-Dinitrophenol
2,6-Dinitrotoluene
2-Nitrophenol
4-Chloro-3 -Methylphenol
4-Nitrophenol
Acenaphthene
Acrolein
Anthracene
Bis(2-ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Chlorobenzene
Chloroethane
Chloroform
Di-n-butyl Phthalate
Di-n-octyl Phthalate
Dimethyl Phthalate
Ethylbenzene
Fluoranthene
Fluorene
Isophorone
Methylene Chloride
n-Nitrosodimethylamine
76
76
76
71
75
75
76
75
74
76
73
76
76
76
76
76
76
75
75
75
76
76
75
75
76
75
1
0
0
5
0
0
0
11
1
0
1
1
18
1
1
1
5
3
1
0
4
4
2
0
3
0
0.011
NA
NA
0.016
NA
NA
NA
0.011
0.424
NA
0.161
0.193
0.015
0.066
0.028
8.34
0.010
0.012
0.020
NA
0.028
0.029
0.010
NA
0.028
NA
0.011
NA
NA
0.064
NA
NA
NA
91.1
0.424
NA
0.161
0.193
143
0.066
0.028
8.34
0.019
0.070
0.020
NA
0.594
0.243
0.021
NA
6.76
NA
0.011
NA
NA
0.052
NA
NA
NA
18.2
0.424
NA
0.161
0.193
8.65
0.066
0.028
8.34
0.014
0.033
0.020
NA
0.239
0.132
0.015
NA
2.27
NA
0.011
NA
NA
0.062
NA
NA
NA
0.587
0.424
NA
0.161
0.193
0.164
0.066
0.028
8.34
0.013
0.018
0.020
NA
0.167
0.129
0.015
NA
0.030
NA
                                5-3

-------
                                     5.0- Wastewater Characteristics
Table 5-2 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Organic Priority Pollutants (continued)
Naphthalene
Phenanthrene
Phenol
Pyrene
Tetrachloroethene
Toluene
Trichloroethene
76
76
76
76
76
76
75
4
4
21
0
2
6
10
0.025
0.101
0.012
NA
0.015
0.029
0.019
1.84
5.50
8.84
NA
0.021
0.653
2.29
0.511
1.47
1.28
NA
0.018
0.183
0.251
0.091
0.143
0.103
NA
0.018
0.103
0.023
Metal Priority Pollutants
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
149
150
150
154
154
154
154
150
154
149
154
149
154
49
66
24
78
121
142
87
33
113
41
48
22
145
0.003
0.001
0.0005
0.002
0.007
0.006
0.006
0.0001
0.008
0.001
0.001
0.001
0.008
1.93
1.65
0.025
12.6
995
190
7,150
0.017
80.9
1.57
2.12
0.113
1,160
0.217
0.183
0.004
1.23
11.7
6.40
91.9
0.001
2.24
0.087
0.138
0.023
27.2
0.042
0.023
0.002
0.088
0.128
0.695
0.414
0.0005
0.141
0.024
0.014
0.021
1.31
Conventional Pollutants
BOD 5-day (Carbonaceous)
Oil and Grease (as HEM)
Total Suspended Solids
65
102
153
54
83
140
3.00
1.08
4.00
64,900
390,000
110,000
3,953
13,884
2,764
837
390
172
Nonconventional Organic Pollutants
1,4-Dioxane
1 -Bromo-2-Chlorobenzene
1 -Bromo-3 -Chlorobenzene
1-Methylfluorene
76
76
76
76
2
0
0
3
0.077
NA
NA
0.014
1.00
NA
NA
2.60
0.539
NA
NA
0.912
0.589
NA
NA
0.123
           5-4

-------
                                     5.0- Wastewater Characteristics
Table 5-2 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Nonconventional Organic Pollutants (continued)
2-Butanone
2-Hexanone
2-Isopropylnaphthalene
2-Methylnaphthalene
2-Propanone
3 ,6-Dimethylphenanthrene
4-Methyl-2-Pentanone
Acetophenone
Alpha-terpineol
Aniline
Benzoic Acid
Benzyl Alcohol
Biphenyl
Carbon Bisulfide
Dibenzofuran
Dibenzothiophene
Diphenyl Ether
Diphenylamine
Hexanoic Acid
Isobutyl Alcohol
m+p Xylene
m-Xylene
Methyl Methacrylate
n,n-Dimethylforrnamide
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
n-Hexadecane
76
76
76
76
76
76
76
76
72
76
76
76
76
76
76
76
76
76
76
76
52
24
76
76
75
76
76
76
76
76
13
3
1
9
41
1
10
1
12
0
11
2
2
0
0
0
0
2
24
3
2
2
0
4
9
23
24
29
19
28
0.057
0.124
7.34
0.011
0.050
8.50
0.052
0.566
0.012
NA
0.071
0.094
0.014
NA
NA
NA
NA
0.024
0.019
0.012
0.013
0.153
NA
0.028
0.017
0.013
0.011
0.012
0.011
0.015
38.3
0.505
7.34
3.14
11.9
8.50
63.7
0.566
14.1
NA
13.2
0.208
0.038
NA
NA
NA
NA
0.026
1,490
1.31
0.352
2.13
NA
0.665
1.33
141
36.8
14.1
109
95.3
3.72
0.263
7.34
0.511
0.943
8.50
6.73
0.566
2.69
NA
1.48
0.151
0.026
NA
NA
NA
NA
0.025
66.6
0.446
0.183
1.14
NA
0.322
0.462
7.97
3.60
1.40
7.82
6.64
0.121
0.161
7.34
0.236
0.215
8.50
0.358
0.566
178
NA
0.189
0.151
0.026
NA
NA
NA
NA
0.025
1.17
0.018
0.183
1.14
NA
0.297
0.132
0.164
0.419
0.190
0.093
0.444
           5-5

-------
                                     5.0- Wastewater Characteristics
Table 5-2 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Nonconventional Organic Pollutants (continued)
n-Octacosane
n-Octadecane
n-Tetracosane
n-Tetradecane
n-Triacontane
o+p Xylene
o-Cresol
o-Xylene
p-Cresol
p-Cymene
Pyridine
Styrene
Trichlorofluoromethane
Tripropyleneglycol Methyl Ether
76
76
76
76
76
24
76
52
76
76
76
75
76
76
7
28
16
30
12
2
1
6
7
2
0
1
1
6
0.035
0.013
0.011
0.011
0.012
0.063
0.039
0.010
0.010
0.021
NA
1.18
0.106
1.93
61.1
264
116
48.5
31.9
1.48
0.039
0.201
4.31
0.051
NA
1.18
0.106
5,254
11.9
13.1
9.92
6.31
3.89
0.774
0.039
0.044
1.02
0.036
NA
1.18
0.106
1,222
0.542
0.198
0.283
0.753
0.666
0.774
0.039
0.013
0.041
0.036
NA
1.18
0.106
245
Nonconventional Metal Pollutants
Aluminum
Barium
Boron
Calcium
Cobalt
Gold
Iron
Magnesium
Manganese
Molybdenum
Sodium
Tin
Titanium
Vanadium
154
150
150
150
150
3
154
150
154
150
150
154
150
150
132
137
127
145
59
1
147
139
142
100
147
64
105
64
0.039
0.001
0.022
0.274
0.005
1.66
0.016
0.088
0.002
0.003
1.61
0.004
0.002
0.002
29,600
31.4
4,150
11,600
35.3
1.66
2,790
213
20,600
112
152,000
1,830
59.7
1.07
242
1.62
136
200
0.723
1.66
49.1
26.1
146
2.74
4,908
30.5
0.886
0.095
2.31
0.106
1.11
39.0
0.034
1.66
4.83
11.6
0.190
0.122
297
0.080
0.040
0.023
           5-6

-------
                                                                           5.0- Wastewater Characteristics
                                   Table 5-2 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Other Nonconventional Pollutants
Ammonia as Nitrogen
Chemical Oxygen Demand (COD)
Chloride
Cyanide
Fluoride
Hexavalent Chromium
Sulfate
Total Dissolved Solids
Total Kjeldahl Nitrogen
Total Organic Carbon (TOC)
Total Petroleum Hydrocarbons
(as SGT-HEM)
Total Phosphorus
Total Recoverable Phenolics
Total Sulfide
47
109
62
9
69
61
86
146
45
72
69
39
109
16
41
103
59
7
66
16
72
146
42
68
47
37
92
5
0.160
6.90
2
0.004
0.130
0.016
1.50
33.5
0.200
4.26
6.55
0.051
0.006
1.00
2,340
330,000
14,400
0.232
190
1.70
46,000
411,420
2,830
85,300
6,230
7,170
33.8
11.0
82.2
25,354
482
0.078
6.00
0.185
1,793
25,197
167
8,280
489
276
1.53
4.40
1.76
4,800
137
0.059
1.10
0.065
121
4,200
34.9
666
46.0
11.0
0.160
2.00
Source: MP&M Sampling Program.
aDue to budgetary constraints, EPA did not analyze all samples for all pollutants.
NA - Not applicable.
                                               5-7

-------
                                                      5.0- Wastewater Characteristics
                           Table 5-3
Rinse Water Pollutant Concentration Data for Oily Operations
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Organic Priority Pollutants
1 , 1 -Dichloroethane
1 , 1 -Dichloroethene
1,1,1 -Trichloroethane
2-Nitrophenol
2,4-Dimethylphenol
2,4-Dinitrophenol
2,6-Dinitrotoluene
4-Chloro-3 -Methylphenol
4-Nitrophenol
Acenaphthene
Acrolein
Anthracene
Bis(2-ethylhexyl) Phthalate
Butyl Benzyl Phthalate
Chlorobenzene
Chloroethane
Chloroform
Di-n-octyl Phthalate
Di-n-butyl Phthalate
Dimethyl Phthalate
Ethylbenzene
Fluoranthene
Fluorene
Isophorone
Methylene Chloride
n-Nitrosodiphenylamine
n-Nitrosodimethylamine
62
62
62
62
48
59
62
60
60
62
53
62
62
62
62
62
62
62
62
62
62
62
62
62
62
62
62
1
0
1
0
0
0
1
2
0
0
0
0
8
0
0
0
17
0
1
0
1
0
0
0
1
0
0
0.039
NA
0.023
NA
NA
NA
0.616
0.023
NA
NA
NA
NA
0.011
NA
NA
NA
0.010
NA
0.017
NA
0.039
NA
NA
NA
0.016
NA
NA
0.039
NA
0.023
NA
NA
NA
0.616
0.050
NA
NA
NA
NA
1.15
NA
NA
NA
0.081
NA
0.017
NA
0.039
NA
NA
NA
0.016
NA
NA
0.039
NA
0.023
NA
NA
NA
0.616
0.037
NA
NA
NA
NA
0.417
NA
NA
NA
0.021
NA
0.017
NA
0.039
NA
NA
NA
0.016
NA
NA
0.039
NA
0.023
NA
NA
NA
0.616
0.037
NA
NA
NA
NA
0.327
NA
NA
NA
0.016
NA
0.017
NA
0.039
NA
NA
NA
0.016
NA
NA
                               5-8

-------
                                     5.0- Wastewater Characteristics
Table 5-3 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Organic Priority Pollutants (continued)
Phenanthrene
Phenol
Pyrene
Tetrachloroethene
Toluene
Trichloroethene
62
62
62
62
62
62
1
4
0
0
2
9
0.527
0.010
NA
NA
0.011
0.011
0.527
8.28
NA
NA
0.045
0.022
0.527
2.14
NA
NA
0.028
0.017
0.527
0.132
NA
NA
0.028
0.018
Metal Priority Pollutants
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
99
100
100
104
104
104
104
100
104
99
104
99
104
20
30
5
30
60
88
24
14
50
9
29
12
85
0.003
0.001
0.001
0.002
0.001
0.008
0.002
0.0001
0.001
0.001
0.001
0.001
0.009
0.256
0.303
0.005
11.9
104
14.7
6.89
0.002
10.3
0.232
0.118
0.036
46.7
0.051
0.044
0.002
0.432
1.97
0.942
0.759
0.001
0.434
0.056
0.022
0.008
1.89
0.037
0.009
0.002
0.012
0.082
0.247
0.050
0.0003
0.099
0.022
0.011
0.002
0.110
Conventional Pollutants
BOD 5-day (Carbonaceous)
Oil and Grease (as HEM)
Total Suspended Solids
51
75
102
42
47
77
3.04
1.12
5.00
12,900
9,195
2,560
730
348
201
47.0
25.5
65.0
Nonconventional Organic Pollutants
1 -Bromo-2-Chlorobenzene
1 -Bromo-3 -Chlorobenzene
1-Methylfluorene
1 -Methylphenanthrene
1,4-Dioxane
62
62
62
62
62
0
0
1
1
1
NA
NA
0.129
1.02
2.02
NA
NA
0.129
1.02
2.02
NA
NA
0.129
1.02
2.02
NA
NA
0.129
1.02
2.02
           5-9

-------
                                    5.0- Wastewater Characteristics
Table 5-3 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Nonconventional Organic Pollutants (continued)
2-Hexanone
2-Isopropylnaphthalene
2-Methylnaphthalene
2-Propanone
3 ,6-Dimethylphenanthrene
4-Methyl-2-Pentanone
Acetophenone
Alpha-Terpineol
Aniline
Benzoic Acid
Benzyl Alcohol
Biphenyl
Carbon Bisulfide
Dibenzofuran
Dibenzothiophene
Diphenyl Ether
Diphenylamine
Hexanoic Acid
Isobutyl Alcohol
m-xylene
m+p Xylene
Methyl Methacrylate
n-Eicosane
n-Decane
n-Docosane
n-Dodecane
n-Hexacosane
n-Hexadecane
n-Octacosane
n-Octadecane
62
62
62
62
62
62
62
52
62
62
62
62
62
62
62
62
62
62
62
13
49
62
62
62
62
62
62
62
62
62
0
1
1
8
1
0
0
2
0
7
2
0
2
1
0
0
0
20
0
0
1
0
13
1
8
6
6
9
3
10
NA
1.57
1.10
0.065
0.811
NA
NA
65.3
NA
0.122
2.73
NA
0.062
0.010
NA
NA
NA
0.013
NA
NA
0.104
NA
0.011
5.01
0.018
1.77
0.011
0.011
0.396
0.018
NA
1.57
1.10
3.10
0.811
NA
NA
67.3
NA
6.61
24.8
NA
0.354
0.010
NA
NA
NA
28.4
NA
NA
0.104
NA
2.41
5.01
6.47
53.3
1.46
52.7
1.37
4.03
NA
1.57
1.10
0.655
0.811
NA
NA
66.3
NA
2.03
13.8
NA
0.208
0.010
NA
NA
NA
1.84
NA
NA
0.104
NA
0.490
5.01
0.964
15.3
0.512
12.2
0.818
0.952
NA
1.57
1.10
0.390
0.811
NA
NA
66.3
NA
1.45
13.8
NA
0.208
0.010
NA
NA
NA
0.189
NA
NA
0.104
NA
0.172
5.01
0.039
7.24
0.268
1.27
0.684
0.159
          5-10

-------
                                    5.0- Wastewater Characteristics
Table 5-3 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Nonconventional Organic Pollutants (continued)
n-Tetradecane
n-Titrosopiperidine
n-Triacontane
n,n-Dimethylformamide
o-Cresol
o-Xylene
o+p Xylene
p-Cresol
p-Cymene
Pyridine
Styrene
Trichlorofluoromethane
Tripropyleneglycol Methyl Ether
62
62
62
62
62
49
13
62
62
62
62
62
62
8
0
2
1
1
1
0
o
3
i
0
0
1
3
0.011
NA
0.039
0.011
0.012
0.056
NA
0.014
0.190
NA
NA
0.036
0.413
160
NA
0.322
0.011
0.012
0.056
NA
0.063
0.190
NA
NA
0.036
4.18
40.0
NA
0.180
0.011
0.012
0.056
NA
0.030
0.190
NA
NA
0.036
2.43
1.07
NA
0.180
0.011
0.012
0.056
NA
0.014
0.190
NA
NA
0.036
2.71
Nonconventional Metal Pollutants
Aluminum
Barium
Boron
Calcium
Cobalt
Gold
Iron
Magnesium
Manganese
Molybdenum
Sodium
Tin
Titanium
Vanadium
104
100
100
100
100
7
104
100
104
100
100
104
100
100
66
86
66
91
19
o
5
77
87
79
41
99
31
43
23
0.060
0.001
0.012
0.050
0.005
0.056
0.011
0.066
0.001
0.008
1.63
0.006
0.001
0.001
321
1.61
838
175
0.627
0.086
453
37.3
135
187
19,100
16.3
1.85
0.182
12.9
0.134
36.6
36.1
0.115
0.074
14.2
9.12
4.07
4.71
524
1.22
0.206
0.026
0.389
0.032
0.223
20.8
0.024
0.081
0.418
6.36
0.043
0.045
113
0.042
0.014
0.014
          5-11

-------
                                                                           5.0- Wastewater Characteristics
                                   Table 5-3 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Other Nonconventional Pollutants
Ammonia as Nitrogen
Chemical Oxygen Demand (COD)
Chloride
Cyanide
Fluoride
Hexavalent Chromium
Sulfate
Total Dissolved Solids
Total Kjeldahl Nitrogen
Total Organic Carbon (TOC)
Total Petroleum Hydrocarbons (as
SGT-HEM)
Total Phosphorus
Total Recoverable Phenolics
Total Sulfide
30
65
21
2
22
54
48
100
23
64
62
10
63
11
14
58
21
2
20
15
39
99
12
60
29
9
43
1
0.020
5.20
3.00
0.010
0.300
0.011
2.33
26.0
0.310
1.72
5.00
0.060
0.005
12.0
10.1
32,700
64,500
1.45
135
0.590
780
120,000
149
10,100
7,367
720
0.800
12.0
2.01
1,690
3,128
0.730
7.50
0.067
96.0
2,955
16.2
490
317
85.5
0.110
12.0
0.125
175
30.0
0.730
0.705
0.022
34.8
756
3.25
83.5
27.0
7.30
0.050
12.0
Source: MP&M Sampling Program.
aDue to budgetary constraints, EPA did not analyze all samples for all pollutants.
NA - Not applicable.
                                              5-12

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                                                                     5.0- Wastewater Characteristics

              As shown in Tables 5-2 and Table 5-3, oil-bearing process water and rinses also
contain numerous organic pollutants.  These pollutants are either components of the oil/water
emulsions or pollutants in the aqueous cleaning solutions.  The maximum organic pollutant
concentration found in process water samples was 5,245 mg/L for tripropyleneglycol methyl
ether from a testing unit operation.  The maximum organic pollutant concentration in the rinse
water samples was 160 mg/L for n-tetradecane in the rinse water for a testing unit operation.
EPA also measured the concentration of chemical oxygen demand (COD) in oil-bearing
wastewater.  The maximum COD concentration found in process water and rinse water samples
was  330,000 mg/L and 32,700 mg/L, respectively. Data in Tables 5-2 and 5-3 show that the
process water samples also contained conventional, nonconventional, and metal pollutants.

              In general, the organic pollutants that EPA detected most frequently were those
associated with petroleum products used in the MP&M industry (e.g., long, straight-chain
organic pollutants associated with oil-based machining and grinding coolants and lubricants).
EPA also detected additional organic cleaners and solvents (e.g., phenol, 2-propanone, bis(2-
ethylhexyl) phthalate, and hexanoic acid).  EPA also detected numerous metals in the oil-bearing
waste streams. However, when compared to the metals concentrations detected in metal-bearing
waste streams (see Appendix C), the oil-bearing waste streams  contained lower median metals
concentrations. While some specific oil-bearing wastewater streams may contain elevated
concentrations of specific metals (e.g., machining of a copper part will generate copper-bearing
wastewater), these streams are typically lower-flow streams as compared to other oil-bearing
streams, resulting in lower treatment influent metals concentrations. These wastewaters may also
contain incidental levels of metals most often in the suspended  or paniculate phase.

5.2           Influent to Oily Wastewater Treatment Systems

              Wastewater containing oil and organic pollutants generated in the oily operations
listed in Table 5-1 generally require treatment to separate oil from the wastewater. Benzene,
toluene, ethylbenzene, and xylenes (BTEX) and other light hydrocarbons, for example, are
moderately soluble in process waters and rinse waters. If the oils are free or floating, a
technology such as oil skimming or ultrafiltration can separate the oil and water.  If the oil is
emulsified, techniques such as chemical emulsion breaking may be required before physical
separation (see Section 8.4.5). Oil/water separation technologies remove organic pollutants that
are more soluble in oil than in water from the wastewater.  Table 5-4 summarizes the MP&M
pollutant concentration data for the influent to oil/water separation, ultrafiltration, and dissolved
air flotation treatment systems. The influent-to-treatment concentrations are typically lower than
the concentrations of process and rinse water due to the number of high-flow, low-concentration
rinses that are commingled prior to treatment.
                                          5-13

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                                                5.0- Wastewater Characteristics
                       Table 5-4

MP&M Pollutant Concentration Data for the Influent to
          Oily Wastewater Treatment Systems
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Organic Priority Pollutants
1 , 1 -Dichloroethane
1 , 1 -Dichloroethylene
1,1,1 -Trichloroethane
2,4-Dimethylphenol
2,4-Dinitrophenol
2,6-Dinitrotoluene
2-Nitrophenol
4-Chloro-m-Cresol
4-Nitrophenol
Acenaphthene
Acrolein
Anthracene
Benzyl Butyl Phthalate
Bis(2-ethylhexyl) Phthalate
Chlorobenzene
Chloroethane
Chloroform
Di-n-butyl Phthalate
Di-n-octyl Phthalate
Dimethyl Phthalate
Ethylbenzene
Fluoranthene
Fluorene
Isophorone
Methylene Chloride
n-Nitrosodimethylamine
93
93
93
92
79
93
93
93
85
93
88
93
92
92
93
93
93
92
93
89
94
92
93
89
93
89
1
0
4
2
0
0
1
20
0
5
1
1
7
73
0
0
6
9
10
0
19
0
7
0
0
0
0.011
NA
0.006
0.017
NA
NA
0.025
0.247
NA
0.006
0.168
0.007
0.024
0.007
NA
NA
0.010
0.011
0.013
NA
0.010
NA
0.010
NA
NA
NA
0.011
NA
0.022
0.270
NA
NA
0.025
3,834
NA
1.82
0.168
0.007
2.73
216
NA
NA
0.038
0.193
19.7
NA
14.0
NA
9.93
NA
NA
NA
0.011
NA
0.013
0.144
NA
NA
0.025
637
NA
0.396
0.168
0.007
0.440
5.82
NA
NA
0.019
0.079
2.37
NA
0.798
NA
1.47
NA
NA
NA
0.011
NA
0.012
0.144
NA
NA
0.025
73.9
NA
0.025
0.168
0.007
0.065
0.173
NA
NA
0.016
0.059
0.332
NA
0.040
NA
0.034
NA
NA
NA
                         5-14

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                                    5.0- Wastewater Characteristics
Table 5-4 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Organic Priority Pollutants (continued)
Naphthalene
Phenanthrene
Phenol
Pyrene
Tetrachloroethene
Toluene
Trichloroethylene
93
93
92
92
93
94
93
15
18
41
2
1
23
0
0.010
0.012
0.020
0.031
0.006
0.006
NA
8.91
5.30
27.1
1.01
0.006
14.0
NA
1.04
0.459
1.09
0.521
0.006
0.795
NA
0.075
0.030
0.136
0.521
0.006
0.040
NA
Metal Priority Pollutants
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
97
97
97
101
101
101
101
97
101
97
101
97
101
38
46
20
67
85
101
74
23
77
14
18
6
98
0.002
0.002
0.0002
0.002
0.003
0.027
0.006
0.0001
0.012
0.001
0.004
0.001
0.123
0.234
0.534
0.187
12.1
15.9
232
210
0.003
18.4
0.124
2.80
0.068
664
0.030
0.048
0.036
0.744
0.630
19.7
16.2
0.001
0.870
0.027
0.273
0.012
22.7
0.022
0.006
0.002
0.023
0.063
0.407
0.247
0.0007
0.172
0.008
0.022
0.001
1.66
Conventional Pollutants
BOD 5-Day (Carbonaceous)
Oil and Grease (as HEM)
Total Suspended Solids
82
97
101
74
95
99
4.00
8.33
6.00
34,800
261,500
100,000
3,137
10,686
3,251
641
848
275
Nonconventional Organic Pollutants
1 -Bromo-2-Chlorobenzene
1 -Bromo-3 -Chlorobenzene
1 -Methylfluorene
88
88
88
0
0
12
NA
NA
0.010
NA
NA
1.72
NA
NA
0.188
NA
NA
0.019
          5-15

-------
                                    5.0- Wastewater Characteristics
Table 5-4 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Nonconventional Organic Pollutants (continued)
1,4-Dioxane
2-Butanone
2-Hexanone
2-Isopropylnaphthalene
2-Methylnaphthalene
2-Propanone
3 ,6-Dimethylphenanthrene
4-Methyl-2-Pentanone
Acetophenone
Alpha-terpineol
Aniline
Benzoic Acid
Benzyl Alcohol
Biphenyl
Carbon Bisulfide
Dibenzofuran
Dibenzothiophene
Diphenyl Ether
Diphenylamine
Hexanoic Acid
Isobutyl Alcohol
m+p Xylene
m-Xylene
Methyl Methacrylate
n,n-Dimethylformamide
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
88
88
88
88
89
88
88
88
88
88
88
88
88
88
88
88
87
88
88
88
88
40
48
88
88
88
88
88
87
88
2
13
2
2
21
74
5
13
3
33
1
4
7
10
5
2
3
0
4
34
0
10
6
0
2
36
44
52
59
34
0.069
0.073
0.505
0.421
0.011
0.060
0.013
0.072
0.014
0.011
0.014
0.098
0.011
0.014
0.045
0.014
0.015
NA
0.738
0.011
NA
0.038
0.018
NA
0.014
0.011
0.012
0.017
0.010
0.011
0.465
6.18
0.512
3.49
440
28.8
1.28
6.72
0.092
189
0.014
0.522
10.8
1.54
0.466
0.018
1.29
NA
1.99
31.9
NA
0.241
0.312
NA
0.023
27.7
79.7
207
109
217
0.267
1.22
0.509
1.96
21.9
3.84
0.583
0.660
0.051
19.4
0.014
0.315
1.63
0.226
0.312
0.016
0.452
NA
1.54
4.27
NA
0.125
0.071
NA
0.019
2.65
2.78
21.0
5.95
8.54
0.267
0.308
0.509
1.96
0.099
0.670
0.371
0.113
0.047
1.43
0.014
0.320
0.141
0.060
0.369
0.016
0.048
NA
1.71
0.561
NA
0.139
0.024
NA
0.019
0.130
0.125
0.594
0.217
0.134
          5-16

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                                    5.0- Wastewater Characteristics
Table 5-4 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Median
Nonconventional Organic Pollutants (continued)
n-Nitrosopiperidine
n-Octacosane
n-Octadecane
n-Tetracosane
n-Tetradecane
n-Triacontane
o+p Xylene
o-Cresol
o-Xylene
p-Cresol
p-Cymene
Pyridine
Styrene
Trichlorofluoromethane
Tripropyleneglycol Methyl Ether
88
88
88
87
88
87
48
88
40
88
88
88
88
93
88
0
10
67
32
64
11
6
0
12
7
12
15
0
0
14
NA
0.031
0.011
0.011
0.011
0.016
0.011
NA
0.012
0.018
0.015
0.014
NA
NA
0.447
NA
70.7
162
56.8
243
25.6
0.030
NA
0.130
1.09
14.6
3.42
NA
NA
1,680
NA
12.9
5.66
3.29
15.0
5.15
0.021
NA
0.059
0.413
1.29
1.02
NA
NA
328
NA
0.266
0.214
0.248
0.203
1.21
0.021
NA
0.046
0.287
0.052
0.063
NA
NA
4.96
Nonconventional Metal Pollutants
Aluminum
Barium
Boron
Calcium
Cobalt
Gold
Iron
Magnesium
Manganese
Molybdenum
Sodium
Tin
Titanium
Vanadium
97
97
97
97
97
2
97
97
101
101
97
101
97
97
82
96
95
96
41
1
95
94
99
80
96
58
72
48
0.076
0.006
0.057
0.154
0.008
2.81
0.604
0.180
0.031
0.003
1.19
0.003
0.003
0.004
134
32.0
686
2,200
1.22
2.81
940
255
29.0
40.3
2,030
85.2
1.80
0.482
13.0
1.89
34.0
156
0.203
2.81
47.7
36.1
1.68
1.25
397
3.05
0.228
0.054
2.48
0.217
5.50
41.0
0.102
2.81
10.6
12.9
0.349
0.088
181
0.053
0.081
0.019
          5-17

-------
                                                                           5.0- Wastewater Characteristics
                                   Table 5-4 (Continued)
Pollutant
No. of Samples
Analyzed3
No. of
Detects
Concentration (mg/L)
Minimum
Maximum
Mean
Other Nonconventional Pollutants
Amenable Cyanide
Ammonia as Nitrogen
Chemical Oxygen Demand (COD)
Chloride
Cyanide
Fluoride
Hexavalent Chromium
Sulfate
Total Dissolved Solids
Total Kjeldahl Nitrogen
Total Organic Carbon (TOC)
Total Petroleum Hydrocarbons (as
SGT-HEM)
Total Phosphorus
Total Recoverable Phenolics
Total Sulfide
4
15
96
11
4
16
78
39
93
15
81
81
24
95
27
0
15
96
11
2
16
12
38
93
15
79
75
24
91
24
NA
0.021
30.0
22.0
0.006
0.500
0.011
16.0
70.0
0.840
7.66
5.07
0.160
0.005
2.00
NA
160
213,000
450
0.007
17.0
1.74
176,000
88,800
1,500
106,000
25,431
240
1,360
18.0
NA
32.7
23,722
83.1
0.007
2.54
0.212
13,957
9,341
222
6,181
1,941
38.9
58.6
7.13
Median

NA
0.500
5,660
27.0
0.007
1.00
0.020
405
2,450
3.10
1,340
507
25.6
0.240
5.50
Source: MP&M Sampling Program.
aDue to budgetary constraints, EPA did not analyze all samples for all pollutants.
NA - Not applicable.
                                              5-18

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                                                                     6.0 - Industry Subcategorization

6.0           INDUSTRY SUBCATEGORIZATION

              This section discusses the Subcategorization evaluated for the final rule (MP&M
Point Source Category).  Section 6.1 discusses the methodology and factors considered when
determining the subcategories evaluated for the final rule. Section 6.2 describes the types of
facilities included in each subcategory evaluated for the final rule.

              As discussed below, EPA proposed effluent limitations and standards for eight
subcategories.  However, for reasons discussed in Section 9.0 and Section VI of the preamble to
the final rule, the final rule only establishes effluent limitations guidelines and standards for new
and existing direct dischargers in one subcategory: Oily Wastes (40 CFR 438, Subpart A).

6.1           Methodology and Factors Considered for Basis of Subcategorization

              In order to address variations between products, raw materials processed, and
other factors that result in distinctly different effluent characteristics, EPA proposed eight
groupings called "subcategories" for the January 2001 proposal and June 2002 Notice of Data
Availability (NODA). EPA retained this subcategory structure for evaluating options for the
final rule.  Regulation of a category using subcategories allows each subcategory to have a
uniform set of effluent limitations that take into account technological achievability and
economic  impacts unique to that subcategory.  The Clean Water Act (CWA) requires EPA, in
developing effluent limitations guidelines and pretreatment standards, to consider a number of
different Subcategorization factors.  The statute also authorizes EPA to take into account other
factors the Agency deems appropriate.  EPA considered the following factors in evaluating the
eight subcategories for the final rule:

              •       Unit operation;
              •       Activity;
              •       Raw materials;
              •       Products;
              •       Size of site;
              •       Geographic location;
              •       Facility age;
              •       Nature of the waste generated;
              •       Economic impacts;
              •       Treatment costs;
              •       Total energy requirements;
              •       Air pollution control methods; and
              •       Solid waste generation and  disposal.

              As a result of this evaluation, EPA retained the eight subcategories for evaluating
options for the final rule as shown in Table 6-1.
                                           6-1

-------
                                                                         6.0 - Industry Subcategorization
                                         Table 6-1
                  Final Subcategories Evaluated in the Final Rule
  Facilities that Generate Metal-Bearing Wastewater
     (With or Without Oil-Bearing Wastewater)
                                      Facilities that Generate Only Oil-Bearing
                                                  Wastewater
                 General Metalsa
            Metal Finishing Job Shopsa
            Non-Chromium Anodizing3
              Printed Wiring Board"
            Steel Forming and Finishing8
                                                   Oily Wastes
                                            Railroad Line Maintenance"
                                              Shipbuilding Dry Docka
Tor reasons discussed in Section 9.0 and Section VI of the preamble to the final rule, EPA did not establish effluent
guidelines for these subcategories.
6.1.1
Factors Contributing to the Subcategorization Structure Evaluated for the
Final Rule
              As discussed in Section 5.0 and Appendix C, facilities performing proposed
MP&M operations1 generate two basic types of waste streams: (1) wastewater with relatively
high metals content (metal-bearing, including hexavalent chromium-bearing and cyanide-
bearing), and (2) wastewater with relatively low metals content and/or relatively high oil and
grease content (oil-bearing). The type of wastewater a facility generates is directly related to the
unit operations it performs. For example, unit operations such as machining, grinding, aqueous
degreasing, and impact or pressure deformation tend to generate a wastewater with relatively
high oil and grease (and associated organic pollutants) loadings but relatively low concentrations
of metal pollutants. Other unit operations such as electroplating, conversion coating, chemical
etching and milling, and anodizing generate higher metals loadings with moderate or low oil and
grease concentrations or generate wastewater containing  both metals and oil and grease.  EPA
defined "oily operations" in the final rule (see 40  CFR 438.2(f) and Appendix B to Part 438) and
these final MP&M operations are  listed in Table 6-2. EPA defined "metal-bearing operations" in
the final rule (see 40  CFR 438.2(d) and Appendix C to Part 438) and these proposed MP&M
operations are listed in Table 6-3.
'EPA evaluated a number of unit operations for the May 1995 proposal, January 2001 proposal, and June 2002
NODA (see Tables 6-2 and 6-3). However, EPA selected a subset of these unit operations for regulation in the final
rule (see Section 1.0). For this section, the term "proposed MP&M operations" means those operations evaluated for
the two proposals, NODA, and final rule. The term "final MP&M operations" means those operations defined as
"oily operations" (see Section 1.0, 40 CFR 438.2(f), and Appendix B to Part 438) and regulated by the final rule.
                                             6-2

-------
                                                                               6.0 - Industry Subcategorization
                                             Table 6-2
                      Oily Operations as Defined by the Final Rule
    Abrasive Blasting
    Adhesive Bonding
    Alkaline Cleaning for Oil Removal
    Alkaline Treatment Without Cyanide
    Aqueous Degreasing
    Assembly/Disassembly
    Burnishing
    Calibration
    Corrosion Preventive Coating
    Electrical Discharge Machining
    Floor Cleaning (In Process Area)
    Grinding
    Heat Treating
    Impact Deformation	
Iron Phosphate Conversion Coating
Machining
Painting-spray or Brush (Including Water Curtains)
Polishing
Pressure Deformation
Solvent Degreasing
Steam Cleaning
Testing (e.g., Hydrostatic, Dye Penetrant, Ultrasonic, Magnetic
Flux)
Thermal Cutting
Tumbling/Barrel Finishing/Mass Finishing/Vibratory Finishing
 Washing (Finished Products)
Welding
 Wet Air Pollution Control for Organic Constituents	
Note: This list is replicated at 40 CFR 438.2(1) with definitions at Appendix B to Part 438.
                                                 6-3

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                                                                               6.0 - Industry Subcategorization
                                             Table 6-3
               Metal-Bearing Operations as Defined by the Final Rule
  1 Abrasive Jet Machining
  1 Acid Pickling Neutralization
  1 Acid Treatment With Chromium
  1 Acid Treatment Without Chromium
  1 Alcohol Cleaning
  • Alkaline Cleaning Neutralization
  • Alkaline Treatment With Cyanide
  1 Anodizing With Chromium
  • Anodizing Without Chromium
  1 Carbon Black Deposition
  1 Catalyst Acid Pre-dip
  1 Chemical Conversion Coating Without Chromium
  • Chemical Milling (or Chemical Machining)
  • Chromate Conversion Coating (or Chromating)
  • Chromium Drag-out Destruction
  1 Cyanide Drag-out Destruction
  1 Cyaniding Rinse
  1 Electrochemical Machining
  1 Electroless Catalyst Solution
  1 Electroless Plating
  1 Electrolytic Cleaning
  1 Electroplating With Chromium
  1 Electroplating With Cyanide
  1 Electroplating Without Chromium or Cyanide
  1 Electropolishing
  1 Galvanizing/Hot Dip Coating
  1 Hot Dip Coating
  1 Kerfing
  ' Laminating	
• Mechanical and Vapor Plating
• Metallic Fiber Cloth Manufacturing
• Metal Spraying (including Water Curtain)
• Painting-immersion (including Electrophoretic,
 "E-coat")
• Photo Imaging
• Photo Image Developing
• Photoresist Application
• Photoresist Strip
• Phosphor Deposition
• Physical Vapor Deposition
• Plasma Arc Machining
• Plastic Wire Extrusion
• Salt Bath Descaling
• Shot Tower - Lead Shot Manufacturing
• Soldering
• Solder Flux Cleaning
• Solder Fusing
• Solder Masking
• Sputtering
• Stripping (Paint)
• Stripping (Metallic Coating)
• Thermal Infusion
• Ultrasonic Machining
• Vacuum Impregnation
• Vacuum Plating
• Water Shedder
• Wet Air Pollution Control
» Wire Galvanizing Flux	
Note: This list is replicated at 40 CFR 438.2(d) with definitions at Appendix C to Part 438.
                                                 6-4

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                                                                      6.0 - Industry Subcategorization

              Although many facilities performing proposed MP&M operations generate both
metal- and oil-bearing wastewater, a large number of facilities, typically machine shops and
maintenance and repair facilities, only generate process wastewater from oily operations (see
Table 6-2). Because the wastewater at these facilities primarily contains oil and grease and other
organic constituents, these facilities use treatment technologies that focus on oil removal only
and do not include the chemical precipitation step needed to treat metal-bearing wastewater.
These treatment technologies generally include oil skimming, chemical emulsion breaking
followed by either gravity flotation, coalescing plate oil/water separators, dissolved air flotation
(DAF), or ultrafiltration.  Therefore, EPA first divided facilities on the basis of unit operations
performed and the nature of the wastewater generated, resulting in the following two wastewater
groups: (1) metal-bearing (with or without oily and organic constituents) group; and (2) oil-
bearing only group. EPA then identified any significant differences in the Subcategorization
factors within the two basic groups.

              Metal-Bearing Wastewater (With or Without Oil-Bearing Wastewater)

              When evaluating facilities generating metal-bearing wastewater (with or without
oil-bearing wastewater) for the final rule, EPA identified five groups of facilities that could
potentially be subcategorized by dominant product, raw materials used, and/or nature of the
waste generated: steel forming and finishing facilities, non-chromium anodizing facilities, metal
finishing job shops, printed wiring board facilities, and general metals facilities. In two of these
groups (non-chromium anodizing and metal finishing job shops), EPA also considered economic
impacts as a Subcategorization factor because of the reduced ability of these facilities to afford
treatment costs. EPA describes its rationale for subcategorizing each of these groups below (see
Section 6.2 for additional detailed discussion and applicability).  In general, EPA identified four
distinct groups within the metal-bearing group that warranted splitting out from the rest of this
group.

              Steel Forming and Finishing Facilities

              EPA proposed moving certain finishing operations subject to the Iron and Steel
Manufacturing effluent guidelines (40 CFR 420) into the scope of the MP&M regulations
because EPA's analyses, at that time, showed these operations to be more similar to MP&M
operations than to iron and steel operations (see W-00-25, Section 14.1, DCN IS10883). In the
MP&M proposed rule, these operations (at stand-alone facilities and at steel manufacturing
facilities) would have been subject to the limits and standards in the proposed Steel Forming and
Finishing Subcategory. This subcategory would have applied to wastewater discharges from
finishing or cold forming operations on steel wire, rod, bar, pipe, or tube. In order to better assess
potential economic impacts associated with the final rule, EPA concluded that facilities
performing these  operations should be evaluated as a separate subcategory when EPA selected
options for the final rule.

              Commentors on the proposed rule stated that these operations and resulting
wastewaters are comparable to those at facilities subject to the Iron and Steel Manufacturing
                                           6-5

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                                                                    6.0 - Industry Subcategorization

effluent guidelines and that these discharges should remain subject to Part 420 rather than the
final MP&M rule. In addition, commentors stated that Part 420 adequately protects the
environment from discharges associated with these activities.

             For reasons discussed in Section 9.0, EPA is not revising limitations or standards
for any facilities that would have been subject to this subcategory. Such facilities will continue to
be regulated by the General Pretreatment Standards (Part 403), local limits, permit limits, and
Iron  and Steel effluent limitations guidelines (Part 420) as applicable.

             Non-Chromium Anodizing Facilities

             The non-chromium anodizers differ from other metal-bearing facilities performing
proposed MP&M operations in that all of their products are primarily of one metal type, anodized
aluminum, and, most importantly, they do not use chromic acid, dichromate sealants, or other
process solutions containing significant concentrations of chromium in their anodizing process.
Table 6-4 shows the percentage of facilities using multiple metal types by subcategory.  EPA's
data  show that these facilities have very low levels of metals (with the exception of aluminum)
and toxic organic pollutants in their wastewater discharges, while other facilities performing
proposed MP&M operations have much greater concentrations of a wider variety of metals.

                                      Table 6-4

   Percentage of Facilities Performing Proposed MP&M Operations Using
                       Multiple Metal Types by Subcategory
Subcategory
General Metals
Metal Finishing Job Shops
Non-Chromium Anodizing
Oily Wastes
Printed Wiring Board
Railroad Line Maintenance
Shipbuilding Dry Dock
Steel Forming and Finishing
Percentage of Facilities by Number of Metal Types Processed
1
31
6
100
46
4
76
57
56
2
32
18
0
17
1
8
0
25
3
13
17
0
32
20
16
29
14
4
8
13
0
3
17
0
14
3
5-10
15
38
0
2
56
0
0
o
6
>10
i
7
0
0
2
0
0
0
Source: MP&M Survey Database.
             In addition, non-chromium anodizing facilities require more extensive wastewater
treatment systems than other metal-bearing facilities performing proposed MP&M operations to
remove both very high concentrations of aluminum (and resulting large volumes of wastewater
treatment sludge) and relatively low levels of alloy metals generated in their wastewater. As a
                                          6-6

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                                                                      6.0 - Industry Subcategorization

result, these facilities have relatively higher treatment costs compared to other metal-bearing
facilities.  EPA also found that, due to their current economic state, non-chromium anodizing
facilities are less able to afford pollutant control technologies as compared to other types of
facilities (see the Economic, Environmental, and Benefits Analysis for the Final Metal Products
& Machinery Rule (EEBA) (EPA-821-B-03-002)). Therefore, based on the differences in raw
materials used, nature of the waste generated, treatment costs, and economic conditions, EPA
concluded that non-chromium anodizing facilities should be evaluated as a separate subcategory
when EPA selected options for the final rule.

              For reasons discussed in Section 9.0, EPA is not revising limitations or standards
for any facilities that would have been subject to this subcategory. Such facilities will continue
to be regulated by the General Pretreatment Standards (Part 403), local limits, permit limits, and
Parts 413  and/or 433, as applicable.

              Metal Finishing Job Shops

              EPA investigated whether to subcategorize the metal finishing and electroplating
job shops  covered currently by the Metal Finishing (40 CFR 433) and Electroplating (40 CFR
413) effluent guidelines (with the exception of printed circuit board manufacturers, which were
analyzed as a separate subcategory as discussed below).  Although these facilities have metal
types that require the same treatment technologies as many other metal-bearing facilities,  EPA
determined that they can be different due to the variability of their raw materials and products as
well as their current economic state compared to other metal-bearing facilities performing
proposed MP&M operations. Metal finishing and electroplating job shops perform  electroplating,
electroless plating, anodizing, coating, and chemical etching and milling, and are "job shops" as
defined in the Metal  Finishing effluent guidelines (i.e., as owning less than 50 percent of the
products processed on site).

              Because metal finishing job shops work on a contract basis, they cannot always
predict the type of plating or other finishing operations required. In addition, because these
facilities work on a large variety of metal types from various customers, their wastewater
characteristics can vary from week to week (or even day to day).  Table 6-5 demonstrates  the
variety of metal types processed at metal finishing job shops as compared to the rest of the
industry.  EPA performed sampling to specifically identify the variability in the wastewater
generated at metal finishing job shops, and found that the variability factors calculated solely on
the analytical wastewater sampling data from metal finishing and electroplating job shops are
higher for most pollutant parameters than those calculated for other metal-bearing subcategories
(see Section 10.1 for a discussion of EPA's variability factor calculations).  In addition, EPA
found that, due to the current economic state, metal finishing job shops are less able to afford
pollutant control technologies compared to other metal-bearing subcategories (see the EEBA).
For these reasons, EPA concluded that metal finishing and electroplating job shops should be
evaluated  as a separate subcategory when EPA selected options for the final rule.
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                                                            6.0 - Industry Subcategorization
                                  Table 6-5
     Percentage of Facilities Performing Proposed MP&M Operations by
                    Subcategory Using Each Metal Type
Metal
Aluminum
Beryllium
Cadmium
Chromium
Cobalt
Copper
Gold
Indium
Iron
Lead
Magnesium
Manganese
Molybdenum
Nickel
Palladium
Platinum
Rhodium
Selenium
Silver
Tantalum
Tin
Titanium
Tungsten
Vanadium
Zinc
Zirconium
Percentage of Facilities by Subcategory
General
Metals
69
<1
2
9
4
29
4
<1
82
6
3
<1
1
17
1
1
1
<1
3
1
15
3
1
0
18
<1
Metal
Finishing
Job Shops
154
0
12
21
0
50
13
0
94
4
6
0
0
54
0
1
7
0
17
0
29
3
0
0
59
0
Non-
Chromium
Anodizing
88
0
0
0
0
0
0
0
12
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Oily
Wastes
67
0
0
<1
1
20
<1
<1
96
1
1
<1
0
5
1
0
0
0
<1
<1
2
2
<1
<1
3
<1
Printed
Wiring
Board
17
0
0
4
2
99
73
0
5
72
0
1
5
79
5
0
3
0
10
0
89
0
0
0
4
0
Railroad
Line
Maintenance
32
0
0
0
0
8
0
0
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Shipbuilding
Dry Dock
14
0
0
0
0
43
0
0
100
0
0
0
0
43
0
0
0
0
0
0
0
0
0
0
0
0
Steel
Forming
and
Finishing
3
0
3
10
3
10
0
0
100
1
0
0
0
5
0
0
0
0
0
0
5
3
0
0
29
0
Source: MP&M Survey Database.
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                                                                      6.0 - Industry Subcategorization

              For reasons discussed in Section 9.0, EPA is not revising any limitations or
standards for facilities that would have been subject to this subcategory. Such facilities will
continue to be regulated by the General Pretreatment Standards (Part 403), local  limits, permit
limits, and Parts 413 and/or 433, as applicable.

              Printed Wiring Board Facilities

              EPA subcategorized printed wiring board facilities based on raw materials, unit
operations performed, primary product, and nature of the waste generated. First, as shown in
Table 6-5, printed wiring board facilities process a more consistent set of metal types (copper,
tin, lead, nickel, and gold) than other metal-bearing facilities.  EPA concluded that this consistent
mix of metal types enables printed wiring board facilities to tailor their treatment technology.
Printed wiring board facilities generally work with copper-clad laminate material, allowing them
to target copper for removal in their wastewater treatment systems or recover the copper using in-
process ion exchange.

              Second, printed wiring board facilities apply, develop, and strip photoresist - a set
of unit operations that is unique to this subcategory. This process produces a higher
concentration of a more consistent group of organic constituents than other facilities in the metal-
bearing group.  Printed wiring board facilities also require chelation breaking more often than
other facilities performing proposed MP&M operations. Finally, the nature of the wastewater
generated at these facilities may also be different because these facilities perform more lead-
bearing operations (e.g., lead/tin electroplating, wave soldering) than other facilities performing
proposed MP&M operations. For these reasons, EPA concluded that printed wiring board
facilities should be evaluated as a separate subcategory when EPA selected options for the final
rule.

              At proposal, EPA included printed wiring board job shops in the Metal Finishing
Job Shops Subcategory based on the similar  economic considerations for job  shops. However,
information submitted by commentors in response to the proposed rule indicates that printed
wiring board job shops are much more similar to Printed Wiring Board Subcategory facilities
than to metal finishing job shops when considering their wastewater characteristics and
operations. Therefore, for the final rule, EPA included printed wiring board job  shops in the
Printed Wiring Board Subcategory evaluated for the final rule.

              For reasons discussed in Section 9.0, EPA is not revising any limitations or
standards for facilities that would have been subject to this subcategory. Such facilities will
continue to be regulated by the General Pretreatment Standards (Part 403), local  limits, permit
limits, and Parts 413 and/or 433, as applicable.

              General Metals Facilities

              After developing separate subcategories for non-chromium anodizing facilities,
metal finishing job shops, printed wiring board facilities, and steel forming and finishing
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                                                                      6.0 - Industry Subcategorization

facilities, EPA grouped the remaining metal-bearing wastewater generating facilities performing
proposed MP&M operations into a subcategory entitled "General Metals" for evaluating options
for the final rule.  This subcategory would be a "catch-all" for metal-bearing wastewater-
generating facilities that do not fall into any of the previous subcategories. For example,
wastewater generated from most manufacturing operations and heavy rebuilding operations (e.g.,
aircraft, aerospace, auto, bus/truck, railroad) would be grouped under the General Metals
Subcategory.

              Based on comments received on the proposed rule, EPA reviewed the unit
operations of printed wiring assembly facilities and determined that they are most similar to the
facilities in the General Metals Subcategory (discussed below). Printed wiring assembly
facilities do not manufacture printed circuit boards, but instead attach circuit boards to other
structures.  Therefore, they do not perform the operations typical of a printed wiring board
facility (e.g., applying photoresist, etching the board, or stripping). At proposal, EPA included
most printed wiring assembly facilities in the General Metals Subcategory; however, some were
included in the Printed Wiring Board Subcategory. For the final rule, EPA included all printed
wiring assembly facilities in the General Metals Subcategory.

              As discussed in the NODA (67 FR 38767), EPA considered establishing a
segment of the Steel Forming and Finishing Subcategory for discharges resulting from
continuous electroplating of flat steel products (e.g., strip, sheet, and plate).  EPA reexamined its
database for facilities that perform continuous steel electroplating, and found that, contrary to its
initial finding, continuous electroplaters do not perform operations similar to other facilities in
this subcategory (i.e., steel forming and finishing facilities performing cold forming on steel
wire, rod,  bar, pipe, and tube) (see Section 24.6.1 of the rulemaking record, DCN 17919). Thus,
EPA included continuous electroplaters performing electroplating and coating operations in the
General Metals Subcategory for evaluating options for the final rule.

              As also discussed in the NODA,  EPA also considered an additional subcategory
for facilities that primarily perform zinc electroplating ("zinc platers"). EPA uses the term "zinc
platers" to describe facilities where over 95 percent of their wastewater is generated from zinc
electroplating lines. Most of these facilities follow electroplating with chromium conversion
coating. Depending on whether or not these facilities operate as a captive or a job shop, EPA had
proposed to include them as part of the General Metals or Metal Finishing Job Shops
Subcategories, respectively. The wastewater characteristics of zinc platers differ from other
facilities in these two subcategories, particularly with respect to their concentrations of zinc.
Where nonzinc platers may have concentrations of 10 to 90 mg/1 zinc in their wastewater prior to
treatment, zinc platers have concentrations of 100 to 800 mg/1 zinc in their wastewater prior to
treatment. However, zinc platers have very low concentrations of other pollutants as compared
to nonzinc platers.

              The NODA explained that EPA was also  considering: (1) creating a separate
subcategory for zinc platers; (2) segmenting zinc platers  within the General Metals and Metal
Finishing Job Shops Subcategories; or (3) retaining the proposed subcategory structure and
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                                                                      6.0 - Industry Subcategorization

establishing numerical limitations and standards for zinc that would be achievable by zinc
platers. NODA commentors supported retaining the proposed subcategories as long as zinc
platers could achieve the zinc numerical limitations and standards. Commentors raised concerns
that creating a separate subcategory or segment to address the limitations for one pollutant would
be confusing and difficult to implement. EPA did not create a separate subcategory or segment
for zinc platers in evaluating the data for the final rule. EPA included zinc platers in the  General
Metals or Metal Finishing Job Shops Subcategories, as applicable, for evaluating options for the
final rule.

              For reasons discussed in Section 9.0, EPA is not revising or establishing any
limitations or standards for facilities that would have been subject to this subcategory. Such
facilities will continue to be regulated by the General Pretreatment Standards (Part 403), local
limits, permit limits, and Parts 413 and/or 433, as applicable.

              In summary, EPA divided facilities that generate metal-bearing wastewater, with
or without oil-bearing wastewater, into the following five subcategories: (1) non-chromium
anodizing facilities; (2) metal finishing job shops; (3) printed wiring board facilities; (4) steel
forming and finishing; and (5) general metals facilities.

              Oil-Bearing Wastewater Only Group

              When evaluating facilities generating oil-bearing wastewater for the final rule,
EPA identified three groups of facilities that could potentially be  subcategorized by size,
location, and dominant product or activity: railroad line maintenance facilities, shipbuilding dry
docks or similar structures, and oily wastes facilities (see Section 6.2 for detailed descriptions of
these subcategories).

              Railroad line maintenance facilities perform routine cleaning and light
maintenance on railroad engines, cars, car-wheel trucks,  or similar parts or machines, and
discharge wastewater  exclusively from oily operations (see Section 1.0).  EPA subcategorized
railroad line maintenance facilities due to their outdoor location, unit operations performed, and
low level of pollutant  loadings they discharge to the environment. EPA also determined that the
railroad line maintenance facilities discharge a much more limited range of organic pollutants
than general oily-wastewater-bearing facilities. These facilities perform only one or more of the
following operations:  assembly/disassembly, floor cleaning, maintenance machining (wheel
truing), touch-up painting, and washing. In addition, because some of these operations are
typically performed outdoors, stormwater collection and treatment is of concern for this
subcategory. Therefore, EPA included railroad line maintenance facilities in the Railroad Line
Maintenance Subcategory evaluated for the final  rule. EPA notes that this subcategory does not
include railroad manufacturing facilities or railroad overhaul or heavy maintenance facilities.

              The second type of facility is dry docks (and similar structures such as graving
docks, building ways,  lift barges, and marine railways). These are large, outdoor areas, exposed
to precipitation, where shipyards perform final assembly, maintenance, rebuilding, and repair
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                                                                      6.0 - Industry Subcategorization

work on large ships and boats. In evaluating options for the final rule, EPA grouped shipbuilding
dry docks and similar structures in the Shipbuilding Dry Dock Subcategory due to their size,
outdoor location, low level of pollutant loadings they discharge to the environment, and the fact
this wastewater is unique to the shipbuilding industry. This subcategory does not include other
proposed MP&M operations that occur at shipyards (e.g.,  shore-side operations such as
electroplating).

              The facilities that generate only oil-bearing wastewater but are not dry docks or
railroad line maintenance facilities fall into the Oily Wastes Subcategory (40 CFR 438, Subpart
A). These facilities meet the applicability criteria in Section 438.1 and discharge only oil-bearing
wastewater and perform one or more oily operations listed in Table 6-2.

             EPA received comments at proposal concerning the definition of "oily
operations" used in the applicability statement of the Oily Wastes Subcategory (see Section
6.2.5). Commentors provided data on several proposed MP&M operations that were not
considered "oily operations" in the proposed rule.  These  operations include:

              •       Abrasive blasting;
              •       Adhesive bonding;
              •       Alkaline treatment without cyanide;
              •       Assembly/disassembly;
              •       Burnishing;
              •       Calibration;
              •       Electrical discharge machining;
              •       Iron phosphate conversion coating;
              •       Painting-spray or brush (including water curtains);
              •       Polishing;
              •       Thermal cutting;
              •       Tumbling/barrel finishing/mass finishing/vibratory finishing;
              •       Washing (finished products);
              •       Welding; and
              •       Wet air pollution control for organic constituents.

The data show low levels of metals in these unit operations. Based on the data received and a
review of other unit operations containing only low metals content,  EPA revised the definition of
"oily operations" in the Oily Wastes Subcategory (see 40 CFR 438.2(f)) to incorporate these
additional unit operations considered in the NOD A, with the exception of bilge water. Bilge
water from ships that are afloat is  not considered an in-scope wastewater for any subcategories of
the MP&M rule  and was inadvertently included in the oily operations definition in  the NODA.
Bilge water from ships in a dry dock or similar structure is considered for the Shipbuilding Dry
Dock Subcategory only.
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                                                                      6.0 - Industry Subcategorization

              In addition, EPA is no longer including wastewater from laundering as part of the
oily operations definition because EPA does not consider it to be a process wastewater under this
rule (67 FR 3 8766).

              For reasons discussed in Section 9.0, EPA is only promulgating limitations and
standards for existing and new direct dischargers in the Oily Wastes Subcategory. EPA is not
promulgating pretreatment standards for existing or new indirect dischargers in this subcategory.

              In summary, EPA divided facilities that generate only oil-bearing wastewater into
the following three subcategories: (1) railroad line maintenance facilities; (2) shipbuilding dry
docks (and similar structures); and (3) oily wastes facilities.

              For reasons discussed in Section 9.0, EPA is not establishing limitations or
standards for any facilities in two subcategories evaluated for the final rule that only discharge
oil-bearing wastewater: Railroad Line Maintenance Subcategory and Shipbuilding Dry Dock
Subcategory. Permit writers and control authorities will establish controls using best professional
judgment (BPJ) to regulate wastewater discharges from these facilities.

6.1.2          Factors That are Not a Basis For MP&M Subcategorization

              During its consideration of the final rule, EPA examined the other factors listed
earlier in this section for possible basis of Subcategorization.  The Agency determined that there
was no basis for subcategorizing facilities  performing proposed MP&M operations based on the
following factors:  geographic location, age of facilities, total energy requirements, air pollution
control methods, and solid waste generation and disposal. These factors are discussed below. In
addition, EPA also considered subcategorizing the facilities performing proposed MP&M
operations according to the 18 industrial sectors proposed in the January 2001 proposal (66 FR
424). As described in Section 1.0, EPA did not regulate the following industrial sectors (Job
Shops, Printed Wiring Board Manufacturing, and Steel Forming & Finishing) as part of the final
rule. As discussed in Section 6.1.1, and further discussed below, EPA determined for evaluating
options for the final rule that Subcategorization based on sectors was appropriate for only one
sector (printed wiring boards), and for portions of three other sectors (railroad, ships and boats,
and job shops).

              For the Steel  Forming and Finishing Subcategory, EPA did not have sector
information from the Iron and Steel Surveys; therefore, EPA evaluated the steel forming and
finishing sites as their own subcategory for the proposed and final rule.  EPA concluded that the
basis for Subcategorization is the difference in the raw material and primary product at these
facilities. Facilities in this proposed subcategory primarily process steel and,  for the most part,
produce uniformly shaped products  such as wire, rod, bar, pipe, and tube.  In addition, this is the
only subcategory for which EPA proposed to cover forming operations under the MP&M
regulations.
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                                                                      6.0 - Industry Subcategorization

              Geographic Location

              Facilities performing proposed MP&M operations are located throughout the
United States. Sites are not limited to any one geographical location, but approximately half are
located east of the Mississippi River, with additional concentrations of facilities in Texas,
Colorado, and California.  EPA did not subcategorize based on geographic location because
location does not affect the ability of facilities to comply with the MP&M final rule. EPA's data
show that well-performing facilities are located throughout the United States.

              Geographic location may impact costs if additional land is required to install
treatment systems, because the cost of the land will vary depending on whether the site is located
in an urban or rural location. However, the treatment systems used to treat wastewater typically
do not have large land requirements, as demonstrated by the fact that many facilities performing
proposed MP&M operations are located in urban settings. The Agency,  however, recognizes that
spatial constraints may present a problem for certain facilities and believes this issue should be
evaluated on a case-by-case basis.

              Water availability is another function of geographical location. Limited water
supply encourages efficient use of water. The Agency encourages installing water recycle and
reuse practices.  Some technology options evaluated for the final rule include pollution
prevention and water conservation because these practices tend to reduce treatment costs and
improve pollutant removals.

              Facility Age

              Figure 6-1 presents the percentage of water-discharging facilities by the decade in
which they were built.  This information is based upon responses to MP&M surveys that reported
the date the facility was built.

              Most facilities have been built since 1970.  Although the  survey respondents
reported a wide range of ages, these facilities must be continually modernized to remain
competitive.  Most of the facilities EPA visited during the MP&M site visit program had recently
modernized some area  of their site. Modernizing production processes and air pollution control
equipment results in generation of similar process waste types regardless of the site's age.
Therefore, EPA did not select facility age as a basis for Subcategorization. EPA's data show that
well-performing facilities include both older and newer facilities.

              Total Energy Requirements

              EPA did not select total energy requirements as a basis for Subcategorization
because the estimated increase in energy consumption for the final rule is trivial (< 0.001
percent) as compared to national energy usage (see Section 13.0). EPA estimated the energy
requirements associated with each MP&M technology option and considered these in estimating
compliance costs (see Section 11.0).
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                                                                         6.0 - Industry Subcategorization
                                                  Before 1920
                                                     2%
                   1990s
                    15%
                                                                                1960s
                                                                                 7%
                                                                                       1970s
                                                                                       17%
              1980s
               48%
                  Source: MP&M Survey Database.
                  Note:   Although there are 44,000 wastewater-discharging facilities performing
                         proposed MP&M operations, only 42,282 are represented in the above pie
                         chart.  Several 1989 and 1996 Long Survey and several Municipality Survey
                         recipients did not provide this information.

         Figure 6-1. Percentage of Wastewater-Discharging Facilities Evaluated
                            for the Final Rule by Decade Built
              Air Pollution Control Methods

              Many facilities 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 sampling program, wastewater generated by these devices does not affect the
effectiveness of technologies used to control wastewater pollutant loadings from proposed
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                                                                      6.0 - Industry Subcategorization

MP&M operations (see Sections 5.2 and 15.3 of the rulemaking record). EPA considers some
wet air pollution control units as proposed MP&M operations, but not as a basis of
subcategorizing the category.

              Industrial Sectors

              EPA considered subcategorizing facilities performing proposed MP&M
operations by industrial sector (e.g., aerospace, aircraft, bus and truck, electronic equipment,
hardware, household equipment, instruments, job shops, mobile industrial  equipment, motor
vehicles, office machines, ordnance, precious metals and jewelry, printed wiring boards, railroad,
ships and boats, stationary industrial equipment, steel forming and finishing, and miscellaneous
metal products).  The Agency determined that Subcategorization based solely on industrial sector
would be complex and confusing because many facilities are in multiple sectors. Adopting such
a Subcategorization scheme would complicate the implementation of the limitations and
standards because permit writers might be required to develop facility-specific limitations across
multiple subcategories.

              The Agency determined that wastewater characteristics, unit operations, and raw
materials used to produce products within a given sector are not always the same from site to
site,  and they are not always different from sector to sector.  Within each sector, facilities can
perform a variety of unit operations on a variety of raw materials. For example, a site in the
aerospace sector may primarily machine aluminum  missile components and not perform any
surface treatment other than alkaline cleaning.  Another site  in that sector may electroplate iron
parts for missiles and perform little or no machining.  Wastewater characteristics from these
facilities may differ because of the different unit operations performed and different raw
materials used. As another example, an automobile manufacturer and an automobile repair
facility are both part of the motor vehicle sector. However, the automobile manufacturer may
perform unit operations that generate metal-bearing and oil-bearing wastewater (aqueous
degreasing, electroplating, chemical conversion coating, etc.) while the automobile repair facility
may perform unit operations that generate only oil-bearing wastewater (machining, aqueous
degreasing, impact deformation, painting, etc.).

              Based on the analytical data collected for this rule, EPA has not found a
statistically significant difference in industrial wastewater discharge among industrial sectors
when performing similar unit operations for cadmium, chromium, copper,  cyanide, lead,
manganese, molybdenum, nickel, oil and grease, silver, tin, total suspended solids (TSS), and
zinc. (The analytical data are available in Sections 5 and 15 of the rulemaking record.) In other
words, after dividing facilities performing proposed MP&M operations according to the unit
operations performed (metal-bearing or oil-bearing  operations), EPA concluded that raw
wastewater has similar treatability across all of the industrial sectors. For example, a facility that
performs chromium electroplating in the process of manufacturing office machines produces
metal-bearing wastewater with similar chemical characteristics as a facility that performs
chromium electroplating in the process of manufacturing a part for a bus.  Similarly, a  facility
that performs machining to repair and maintain an airplane engine produces oil-bearing
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                                                                      6.0 - Industry Subcategorization

wastewater that has similar chemical characteristics to a facility that performs machining to
repair and maintain construction machinery.

              Most proposed MP&M operations are not unique to a particular sector and are
performed across all sectors. For example, all sectors perform several of the major wastewater-
generating unit operations (e.g., alkaline treatment, acid treatment, machining, electroplating).
And, for the most part, 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.  Therefore, a facility in
any one of the proposed industrial sectors can generate metal-bearing or oil-bearing wastewater
(or a combination of both) depending on what unit operations the  facility performs.

              Due to the reasons stated above, EPA determined that a regulation based on
industrial sector would create a variety of implementation issues for state and local regulators as
well as for those multiple-sector facilities.  As a result, EPA did not use industrial  sector as a
basis for subcategorizing the industry.

              Solid Waste Generation and Disposal

              Physical and chemical characteristics of solid waste generated by facilities
performing proposed MP&M operations 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. The Subcategorization scheme that EPA is  promulgating should account
for any variations in solid waste generation and disposal. EPA considered the amount of sludge
generated as a result of the MP&M technology options, and included disposal of these  sludges in
the compliance cost estimates (see Section 11.0) and non-water quality impact assessments (see
Section 13.0).

6.2           General Description of Facilities in Each Subcategory Evaluated for the
              Final Rule

              Below is a general description of the types of facilities that fall within each of the
subcategories evaluated for the final rule.  Sections  11.0 and 12.0  present information on
compliance costs and pollutant reductions, respectively, evaluated for the final rule for each
proposed subcategory. However, for reasons discussed in Section 9.0  and Section VI of the
preamble to the final rule,  the final rule establishes effluent limitations guidelines and standards
for new and existing direct dischargers in one subcategory: Oily Wastes  (40 CFR 438,  Subpart
A).

6.2.1          General Metals  Subcategory Evaluated for the Final Rule

              As discussed in Section 6.1, the General Metals Subcategory evaluated for the
final rule is a "catch-all" for facilities performing proposed MP&M operations that discharge
metal-bearing wastewater (with or without oil-bearing wastewater) that do not fit the
applicability of the Metal Finishing Job Shops, Non-Chromium Anodizing, and Printed Wiring
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Board Subcategories evaluated for the final rule. This proposed subcategory also includes
general metals facilities that are owned and operated by the federal government, states and
municipalities.  General metals facilities typically perform manufacturing or heavy rebuilding of
metal products, parts, or machines. Facilities that perform metal finishing or electroplating
operations on site, but do not meet the definition of a job shop (i.e., captive shops), would fit in
the proposed General Metals Subcategory.  EPA also includes continuous electroplaters of flat
steel products (e.g., strip, sheet, and plate) in the General Metals Subcategory evaluated for the
final rule.

              Wastewater discharges from railroad overhaul or heavy maintenance facilities
may be covered by the MP&M effluent guidelines (Subpart A), the Metal Finishing Point Source
Category (40 CFR 433), or by other effluent limitations guidelines, as applicable. This provision
is codified at 40 CFR 438. l(d).  Facilities engaged in the manufacture, overhaul or heavy
maintenance of railroad engines, cars, car-wheel trucks, or similar parts or machines ("railroad
overhaul or heavy maintenance facilities") typically perform different unit operations than
railroad line maintenance facilities. Railroad line maintenance facilities perform routine cleaning
and light maintenance on railroad engines, cars, car-wheel trucks, or similar parts or machines,
and discharge wastewater exclusively from oily operations. These facilities only perform one or
more of the following operations: assembly/disassembly, floor cleaning, maintenance machining
(wheel truing),  touch-up painting, and washing.

              Railroad overhaul or heavy maintenance facilities are engaged in the manufacture,
overhaul,  or heavy maintenance of railroad engines, cars, car-wheel trucks, or similar parts or
machines. These facilities typically perform one or more of the same operations as railroad line
maintenance facilities and one or more of the following operations: abrasive blasting, alkaline
cleaning, aqueous degreasing, corrosion preventive coating, electrical discharge machining,
grinding, heat treating, impact deformation, painting, plasma arc machining, polishing, pressure
deformation, soldering/brazing, stripping (paint), testing, thermal cutting, and welding.
Depending on the operations performed, railroad overhaul or heavy maintenance facilities may
be included in the proposed General Metals Subcategory or the Oily Wastes Subcategory.

              EPA estimates that there are approximately 10,914 indirect dischargers and 250
direct dischargers in the General Metals Subcategory evaluated for the final rule. EPA currently
regulates 99 percent of the facilities in this proposed subcategory by existing effluent guidelines.
Some general metals facilities are currently covered by multiple  regulations. The Agency
estimates that, based on responses to  its questionnaires, the Metal Finishing (40 CFR 433) and
Electroplating (40 CFR 413) effluent guidelines cover approximately 89 percent and 16 percent,
respectively, of general metals facilities. Approximately 50 percent of the general metals
facilities are covered by other metal-related effluent guidelines (see Section 1.2.7). Facilities in
the proposed General Metals Subcategory are specifically not regulated by the final rule (see 40
CFR438.1(b)).
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6.2.2          Metal Finishing Job Shops Subcategory Evaluated for the Final Rule

              Facilities in the Metal Finishing Job Shops Subcategory evaluated for the final
rule met the following criteria: (1) perform one or more of the following five operations:
electroplating, electroless plating, anodizing, chemical conversion coating (chromating,
phosphating, passivation, and coloring), and chemical etching and milling, and (2) own not more
than 50 percent (on an annual area basis) of the materials undergoing metal finishing. (Note that
printed wiring board job shops are in the Printed Wiring Board Subcategory evaluated for the
final rule based on the operations performed and wastewater characteristics.)

              The Agency estimates that there are approximately 1,530 indirect dischargers and
12 direct dischargers in the Metal Finishing Job Shops Subcategory evaluated for the final rule.
EPA currently regulates all facilities in this proposed Subcategory under the existing Metal
Finishing or Electroplating effluent guidelines and standards.

              EPA has identified approximately 32,139 facilities that meet the definition of job
shop but do not perform one or more of the five metal finishing operations listed above. EPA
does not consider such job shops to be part of the Metal Finishing Job Shops Subcategory. These
other job shops typically perform assembly, painting, and machining on a contract basis and are
included in the General Metals, Oily Wastes, or Printed Wiring Board Subcategories evaluated
for the final rule. Facilities in the Metal Finishing Job Shops proposed Subcategory are
specifically not regulated by the final rule (see 40 CFR 438.l(b)).

6.2.3          Non-Chromium Anodizing Subcategory Evaluated for the Final Rule

              Facilities in the Non-Chromium Anodizing Subcategory evaluated for the final
rule performed aluminum anodizing without using chromic  acid or dichromate sealants.
Anodizing is a surface conversion operation used to alter the properties of aluminum for better
corrosion resistance and heat transfer. Generally, non-chromium anodizing facilities perform
sulfuric acid anodizing; however, facilities can use other acids (except chromic acid), such as
oxalic acid, for aluminum anodizing.  In evaluating options  for the final rule, EPA included
anodizers that use chromic acid or dichromate in the proposed General Metals Subcategory or, if
they operate as a job shop, in the proposed Metal Finishing Job Shops Subcategory.

              Some facilities that could potentially fall into the proposed Non-Chromium
Anodizing  Subcategory also may perform other metal surface finishing operations. Jf these
facilities commingle wastewater from their non-chromium anodizing operations with wastewater
from other  surface finishing operations (e.g., chromic acid anodizing, electroplating, chemical
conversion coating) for treatment, or perform chromium-bearing operations on site, they would
not be included in the proposed Non-Chromium Anodizing  Subcategory. Instead, the proposed
General Metals or Metal Finishing Job Shops Subcategories would apply.

              EPA estimates that there are approximately 122 indirect dischargers in the
proposed Non-Chromium Anodizing Subcategory. EPA did not identify any direct discharging
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non-chromium anodizers in its survey efforts. The wastewater generated at non-chromium
anodizing facilities contains relatively low levels of metals, with the exception of aluminum, and
low levels of toxic organic pollutants. Facilities in the proposed Non-Chromium Anodizing
Subcategory are specifically not regulated by the final rule (see 40 CFR 438.l(b)).

6.2.4          Printed Wiring Board Subcategory Evaluated for the Final Rule

              The Printed Wiring Board Subcategory evaluated for the final rule includes
wastewater discharges from the manufacture and repair of printed wiring boards (i.e., circuit
boards), including job shops.  However, printed wiring assembly facilities are included in the
General Metals Subcategory evaluated for the final rule.  EPA currently regulates all facilities in
this proposed Subcategory by the existing Metal Finishing or Electroplating effluent limitation
guidelines and standards. EPA estimates that there are approximately 840 indirect dischargers
and 8 direct dischargers in the Printed Wiring Board Subcategory evaluated for the  final rule.
Facilities in the Printed Wiring Board Subcategory evaluated for the final rule are specifically not
regulated by the final rule (see 40 CFR 438. l(b)).

6.2.5          Steel Forming and Finishing Subcategory Evaluated for the Final Rule

              Facilities in the Steel Forming and Finishing Subcategory evaluated  for the final
rule performed MP&M finishing operations and/or cold forming operations on steel wire, rod,
bar, pipe, or tube. This Subcategory does not include facilities that perform those operations on
other base materials.  Generally, steel forming and finishing facilities perform acid pickling,
annealing, conversion coating (e.g., zinc phosphate, copper sulfate), hot dip coating and/or
electroplating of steel wire or rod, heat treatment, welding, drawing, patenting, and oil tempering.

              EPA estimates that there are approximately 110 indirect and 43 direct dischargers
in the proposed Steel Forming and Finishing Subcategory. EPA currently regulates all facilities
in this proposed Subcategory under the Iron and Steel Point Source Category (40 CFR 420).
Facilities in the proposed Steel Forming and Finishing Subcategory are specifically not regulated
by the final rule (see 40 CFR 438.l(b)).

6.2.6          Oily Wastes Subcategory

              The Oily Wastes Subcategory established in the final rule is a "catch-all" for
facilities in one or more of the 16 industrial sectors (see Section  1.0) performing proposed "oily
operations" (see Table 6-2) and are not specifically excluded by the applicability to the final rule
(see Section 1.0 and 40 CFR 438.1). EPA defined the applicability of this Subcategory by the
presence of specific unit operations (see Table 6-2).  Facilities in the proposed Railroad Line
Maintenance or Shipbuilding Dry Dock Subcategories (see below) are not subject to the Oily
Wastes Subcategory in the final rule (see Section 1.0 and 40 CFR 438.l(d) and 438.1(e)(5)).
Facilities in the Oily Wastes Subcategory are predominantly machine shops or maintenance and
repair shops. This Subcategory also includes federal, municipal, and state-owned facilities
performing only the listed operations.
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              In the final rule, EPA also clarified the applicability of certain unit operations.
EPA defined "corrosion preventive coating" in the final rule (40 CFR 438.2(c)) as "the
application of removable oily or organic solutions to protect metal surfaces against corrosive
environments. Corrosion preventive coatings include, but are not limited to: petrolatum
compounds, oils, hard dry-film compounds, solvent-cutback petroleum-based compounds,
emulsions, water-displacing polar compounds, and fingerprint removers and neutralizers.
Corrosion preventive coating does not include electroplating, or chemical conversion coating
operations." EPA's analytical database shows that wastewater generated from phosphate
conversion coating operations may contain high levels of zinc, nickel, and manganese (see
Section 16.5.1 of the rulemaking record, DCN 16715).

              However, based on comments on the January 2001 proposal and June 2002
NOD A, EPA added iron phosphate conversion coating to the final list of oily operations (see 40
CFR 438.2(f) and Appendix B to Part 438). EPA defined iron phosphate conversion coating as
"the process of applying a protective coating on the surface of a metal using a bath consisting of
a phosphoric acid solution containing no metals (e.g., manganese, nickel, or zinc) or a phosphate
salt solution (i.e.,  sodium or potassium salts of phosphoric acid solutions) containing no metals
(e.g., manganese,  nickel, or zinc) other than sodium  or potassium. Any metal concentrations in
the bath are from the substrate." EPA notes that iron phosphate conversion coating should be
distinguished from zinc, manganese, or nickel phosphate conversion coating based on the
constituents of the bath. Manganese, nickel, or zinc phosphate conversion coating baths contain
metals in addition to what may be added from the substrate.

              If a facility discharges wastewater from any of the operations listed in Table 6-2,
but also discharges wastewater from any of the operations listed in Table 6-3, it does not meet
the criteria of the Oily Wastes Subcategory but instead would have been included under either the
proposed General Metals Subcategory or another metal-bearing wastewater proposed
subcategory.  EPA determined that both of the following wastewaters require some form of
wastewater treatment (e.g., chemical precipitation) to properly remove metals: (1) wastewaters
from metal-bearing operations; and (2) wastewaters commingled from metal-bearing operations
and oily operations. Thus, the final regulations do not apply to the discharge of wastewater from
oily operations commingled with wastewater from metal-bearing operations. Additionally, the
regulations in the  final rule do not apply to process wastewater discharges subject to the
limitations and standards of other effluent limitations guidelines (e.g., Metal Finishing (40 CFR
433) or Iron and Steel Manufacturing (40 CFR 420)). These provisions are codified in the final
rule at 40 CFR 438. l(b):

              "The regulations in this part do not apply to process wastewaters from metal-
              bearing operations (as defined at §438.2(d) and Appendix C of this part) or
              process wastewaters which are subject to the limitations and standards of other
              effluent limitations guidelines (e.g., Metal Finishing (40 CFR 433) or Iron and
              Steel Manufacturing (40 CFR 420)). The regulations in this  part also do not apply
              to process wastewaters from oily operations  (as defined at §438.2(f) and
              Appendix B of this part) commingled with process wastewaters already covered
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              by other effluent limitations guidelines or with process wastewaters from
              metal-bearing operations. This provision must be examined for each point source
              discharge at a given facility."

              Wastewater discharges from railroad overhaul or heavy maintenance facilities
may be covered by the MP&M effluent guidelines (Subpart A), the Metal Finishing Point Source
Category (40 CFR 433), or by other effluent limitations guidelines, as applicable. This provision
is codified at 40 CFR 438. l(d).  Facilities engaged in the manufacture, overhaul or heavy
maintenance of railroad engines, cars, car-wheel trucks, or similar parts or machines ("railroad
overhaul or heavy maintenance facilities") typically perform different unit operations than
railroad line maintenance facilities.  Railroad line maintenance facilities perform routine cleaning
and light maintenance on railroad engines, cars, car-wheel trucks, or similar parts or machines,
and discharge wastewater exclusively from oily operations. These facilities only perform one or
more of the following operations: assembly/disassembly, floor cleaning, maintenance machining
(wheel truing), touch-up painting, and washing.

              Railroad overhaul or heavy maintenance facilities are engaged in the manufacture,
overhaul, or heavy maintenance of railroad engines, cars, car-wheel trucks, or similar parts or
machines. These facilities typically perform one or more of the same operations as railroad line
maintenance facilities and one or more of the following operations:  abrasive blasting, alkaline
cleaning, aqueous degreasing, corrosion preventive coating, electrical discharge machining,
grinding, heat treating, impact deformation, painting, plasma arc machining, polishing, pressure
deformation, soldering/brazing, stripping (paint), testing, thermal cutting, and welding.
Depending on the operations performed, railroad overhaul  or heavy maintenance facilities may
be included in the proposed General Metals Subcategory or the Oily Wastes Subcategory.

              EPA estimates that there are approximately 26,824 indirect dischargers and 2,382
direct dischargers in the Oily Wastes Subcategory.  EPA has concluded that less than two percent
of the MP&M process wastewater discharged from the facilities in this Subcategory is covered by
existing effluent guidelines. Limitations and standards for this Subcategory are given in Section
1.0 and at 40 CFR 438, Subpart A (Oily Wastes).

6.2.7          Railroad Line Maintenance Subcategory Evaluated for the Final Rule

              The Railroad Line Maintenance Subcategory evaluated for the final rule included
facilities that perform routine cleaning and light maintenance (mostly consisting of parts
replacement) on railroad engines, cars, car-wheel trucks, and  similar parts or machines. These
facilities discharge wastewater from only those proposed MP&M operations that EPA defines as
oily operations (see Table 6-2).  The wastewater generated at railroad line maintenance facilities
contains relatively low levels of metals and toxic organic pollutants. Because these operations
are conducted outdoors, these facilities may also discharge large volumes of stormwater that may
or may not be commingled with process wastewater.
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              Railroad line maintenance facilities are similar to facilities in the Oily Wastes
Subcategory in that they produce oil-bearing wastewater and do not perform MP&M operations
that generate wastewater that requires metals removal treatment technology. This proposed
subcategory does not include railroad manufacturing facilities or railroad overhaul or heavy
maintenance facilities.  Railroad manufacturing facilities and railroad overhaul or heavy
maintenance facilities perform operations more similar to operations in the proposed General
Metals Subcategory (e.g., acid treatment without chromium) and Oily Wastes Subcategory (e.g.,
heat treating and impact deformation).

              EPA estimates that there are approximately 820 indirect dischargers and 9 direct
dischargers in the proposed Railroad Line Maintenance Subcategory  evaluated for the final rule.
Facilities in the proposed Railroad Line Maintenance Subcategory are specifically not regulated
by the final rule (see Section 1.0 and 40 CFR 438.l(d)). Additionally, EPA did not establish and
limitations and standards for the proposed General Metals Subcategory (see Section 9.0).
Consequently, railroad  manufacturing facilities and railroad overhaul or heavy maintenance
facilities in the proposed General Metals Subcategory will continue to be regulated by the
General Pretreatment Standards (Part 403), local limits, permit limits, and Parts 413 and/or 433,
as applicable.

6.2.8          Shipbuilding Dry Dock Subcategory

              The Shipbuilding Dry Dock Subcategory evaluated for the final rule included
wastewater generated in or on dry docks and similar structures such as graving docks, building
ways, marine railways,  and lift barges at shipbuilding facilities (or shipyards). Shipbuilding
facilities use these structures to maintain, repair, or rebuild existing ships, or perform the final
assembly and launching of new ships (including barges). Shipbuilders use these structures to
reach surfaces and parts that would otherwise be under water. Because dry  docks and similar
structures include sumps or containment systems, shipyards can control the discharge of
pollutants to surface water. Typical proposed MP&M operations that occur in dry docks and
similar structures include: abrasive blasting; hydro-blasting; painting; welding; corrosion
preventive coating; floor cleaning; aqueous degreasing; and testing. Not all of these proposed
MP&M operations generate wastewater. The proposed subcategory also included wastewater
generated when a shipyard cleans a ship's hull in a dry dock (or similar structure) to remove
marine life (e.g., barnacles) in preparation for performing proposed MP&M operations.

              This subcategory included only process wastewater generated and discharged
from proposed MP&M operations inside and outside ships (including bilge water) that occur in
or on dry docks or similar structures. The Agency is not including process wastewater from
proposed MP&M operations that is generated at other locations at the shipyard ("on-shore"
operations) in this proposed subcategory. EPA included these wastewaters from these "on-
shore" shipbuilding operations (e.g., electroplating, plasma arc cutting) in the proposed General
Metals Subcategory or  Oily Wastes Subcategory.  Also, EPA is not including  wastewater
generated onboard ships when they are afloat (i.e., not in dry docks or similar structures). For
U.S. military ships, EPA is in the process of establishing standards under the Uniform National
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                                                                      6.0 - Industry Subcategorization

Discharge Standards (UNDS) pursuant to Section 312(n) of the CWA (see 64 FR 25125; May
10, 1999) to regulate discharges of wastewater generated onboard these ships when they are in
U.S. waters and are afloat (e.g., at a shipyard's dock).

              In addition to wastewater from proposed MP&M operations, three other types of
water streams are in or on dry docks and similar structures: flooding water, dry dock ballast
water, and stormwater. Flooding water enters and exits the dry dock or similar structure prior to
performing any MP&M operations.  For example, in a graving dock, the gates are opened,
allowing flooding water in and ships to float inside the chamber. Then the flooding water is
drained, leaving the ship's exterior exposed so shipyard employees can repair and maintain the
ship's hull. Dry  dock ballast water serves a similar purpose.  It is used to lower (or sink) a
floating dry dock so that a ship can float over it. Then the dry dock ballast water is pumped out,
raising the dry dock with  the ship on top. Flooding water and dry dock ballast water are not
directly associated with proposed MP&M operations. Finally, because these structures are
located outdoors and are exposed to the elements, stormwater may fall in or on the dry dock or
similar structures.

              In its evaluation, EPA excluded all three of these water streams (i.e., flooding
water, dry dock ballast water, and stormwater) from the proposed definition of process
wastewater specific to the Shipbuilding Dry Dock Subcategory. Stormwater at these facilities is
covered by EPA's Storm  Water Multi-Sector General Permit, similar general permits issued by
authorized states, and individual stormwater permits.  In general, stormwater permits at shipyards
include best management practices (BMPs) that are designed to prevent the contamination of
stormwater. For example, these practices include sweeping areas after paint stripping or painting
are completed.

              Many shipyards perform only dry proposed MP&M operations in their dry docks
(and similar structures) or do not discharge wastewater generated in dry docks (and similar
structures) from proposed MP&M operations. Many shipyards prefer to handle this wastewater
as hazardous, and contract haul it off site due to the possible presence of copper or tin (used as an
antifoulant) in paint chips from paint stripping operations. The wastewater discharged from  dry
docks and similar structures contains relatively low levels of metals and toxic organic pollutants.

              EPA estimates that there are nine indirect dischargers and  six direct dischargers in
the Shipbuilding Dry Dock Subcategory evaluated for the final rule.  Many shipbuilders operate
multiple dry docks (or similar structures); this is the number of estimated facilities (not dry
docks) that discharge process wastewater from proposed MP&M operations at dry docks or
similar structures.  Facilities in the proposed Shipbuilding Dry Dock Subcategory are specifically
not regulated by the final  rule (see Section 1.0 and 40 CFR 438. l(e)(5)).
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                                                                  7.0 - Selection of Pollutant Parameters

7.0           SELECTION OF POLLUTANT PARAMETERS

              This section discusses the criteria EPA used to identify pollutants of concern
(POCs) and regulated pollutants. For the final rule, EPA evaluated process wastewater from
proposed MP&M operations1 to determine the presence of priority, conventional, and
nonconventional pollutant parameters.  EPA reviewed data on 308 metal and organic pollutant
parameters listed in The 1990 Industrial Technology Division List of Analytes (1) under the
MP&M final rule.  These pollutants are listed in Section 3.0, Tables 3-5 and 3-6.  The Agency
also evaluated regulating 24 conventional and other nonconventional pollutant bulk parameters
under the MP&M rule. These pollutants are listed in Section 3.0, Table 3-7.

              Section 7.1 discusses the criteria EPA used to identify POCs for the MP&M final
rule. POCs are pollutants EPA has identified  at significant concentrations in process wastewater
from proposed MP&M operations. While EPA generally considers the full list of POCs in its
analysis, it regulates only a subset of these pollutants. Section 7.2 presents the criteria EPA used
to select the regulated pollutants.  Section 7.3  presents the references used in this section.

7.1           Identification of Pollutants of Concern

              EPA performed the POC analysis using the analytical data from the Phase I and
Phase II sampling programs. The POC analysis identifies those pollutants present in industry
wastewater at significant concentrations. These pollutants are evaluated in the pollutant
reduction analysis (Section 11.0) and further considered for regulation.  To identify POCs for the
MP&M rulemaking, EPA analyzed for 329 pollutants in over 1,994 samples of unit operation
processes and rinse water, wastewater treatment influent, and wastewater treatment effluent
during the Phase I and Phase n sampling programs.  EPA did not use data collected during the
post-proposal sampling program and industry-supplied data in the POC analysis.  The Agency
excluded acidity, total alkalinity, and pH from the POC analysis since these pollutant parameters
do not have a detection limit.

              EPA performed the POC analysis using all data across proposed subcategories
evaluated for the final rule. When determining regulated pollutants (Section 7.2), EPA
considered proposed subcategory-specific factors. EPA identified POCs primarily using data
from proposed MP&M operations (both process baths and rinses) and wastewater treatment
influent data.  The pollutants generated depend more on the nature of the unit operations than the
subcategory in which the operation is performed (e.g., pollutants present in a machinery
operation conducted on steel parts will be similar across subcategories). While the oil-bearing
subcategories exclude operations generating high concentrations of metal pollutants, EPA still
'Note: EPA evaluated a number of unit operations for the May 1995 proposal, January 2001 proposal, and June 2002
NODA (see Tables 4-3 and 4-4). However, EPA selected a subset of these unit operations for regulation in the final
rule (see Section 1.0). For this section, the term "proposed MP&M operations" means those operations evaluated for
the two proposals, NODA, and final rule. The term "final MP&M operations" means those operations defined as
"oily operations" (see Section 1.0, 40 CFR 438.2(f), and Appendix B to Part 438) and regulated by the final rule.

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                                                                 7.0 - Selection of Pollutant Parameters

detected many metal pollutants in oil-bearing wastewaters (see Section 5.0) and therefore
considered these to be POCs.

              EPA reduced the list of 329 analyzed pollutants to 132 POCs by retaining only
those pollutants that met the following criteria:

              •       EPA detected the pollutant in at least three samples collected during the
                     MP&M sampling programs. For this evaluation, EPA considered all
                     samples collected from Phase I and Phase II process water, rinse water,
                     wastewater treatment influent, or wastewater treatment effluent.

              •       The average of all the detected concentrations of the pollutant in samples
                     of wastewater from proposed MP&M operations and treatment system
                     influents was at least five times the minimum level (ML).  EPA describes
                     the ML as "the  lowest level at which the entire analytical system must give
                     a recognizable signal and an acceptable calibration point for the
                     analyte" (2).  EPA evaluated the unit  operation, rinse, and treatment
                     influent data to identify those pollutants present in raw wastewater.  EPA
                     did not evaluate the effluent data for this step because the treatment
                     systems are designed to remove pollutants, so including effluent data in
                     this step may have artificially lowered the average concentration.

              •       EPA analyzed the pollutant in a quantitative manner following the
                     appropriate quality assurance/quality  control  (QA/QC)  procedures.  Thus,
                     wastewater analyses performed solely for certain semiquantitative
                     "screening" purposes did not meet this criterion, and EPA excluded these
                     results from the POCs analysis. EPA performed these semiquantitative
                     analyses only in unusual cases (e.g., to qualitatively screen for the presence
                     of a rare metal such as osmium).

              For the first criterion, EPA combined data from the unit operation, treatment
system influent, and treatment system effluent wastewater samples to determine the total number
of samples in which each pollutant was detected.

              EPA calculated the average detected pollutant concentrations of the unit operation
wastewater and treatment system influent samples to determine if the data met the second
criterion.  In this analysis, EPA focused only on detected pollutants so nondetected pollutants
were not included. For pollutants not meeting the second criterion based on this calculation (i.e.,
the average detected pollutant concentration in samples of unit operation wastewater and
treatment  system influent samples was less than five times the ML), EPA also calculated the
average detected pollutant concentration in the treatment system effluent and determined whether
those averages exceeded five times the ML.  EPA took this step for two reasons. First, the
Agency wanted to identify any pollutants that were generated during treatment.  For example,
EPA determined that chloroform can be produced in alkaline chlorination systems and adjusted

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                                                                 7.0 - Selection of Pollutant Parameters

the pollutant removal model accordingly.  Second, matrix interferences associated with unit
operation and wastewater treatment influent samples may have masked the presence of a
pollutant in a unit operation or influent sample. For six pollutants (1,1-dichloroethene,
chloroform, diphenyl ether, isophorone, n-nitrosopiperidine, and trichlorofluoromethane), the
average treatment system effluent concentrations exceeded five times the ML. Consequently,
EPA considered these compounds POCs.

              As explained above, EPA started with a possible list of 329 pollutants. The
Agency excluded acidity, total alkalinity, and pH from the POC analysis since these pollutant
parameters do  not have a detection limit. EPA also excluded oil and grease (EPA Method 413.2)
from the POC  analysis since oil and grease (as HEM) was included.  Therefore, these pollutant
parameters were not considered for regulation under the final MP&M rule.

              Of the 324 remaining pollutants EPA initially considered regulating under
MP&M, EPA excluded 192 as POCs because they failed to meet the following criteria:

              •      EPA did not detect 113  pollutant parameters in samples collected during
                     the Phase I and Phase II MP&M sampling programs. Table 7-1 lists these
                     pollutants.

              •      EPA detected 50 pollutants in less than three samples collected during the
                     Phase I and Phase n MP&M sampling programs. Table 7-2 lists these
                     pollutants.

              •      EPA detected 23 pollutants at average detected concentrations that were
                     less than five times the ML in unit operation wastewater and treatment
                     system  influent. Table 7-3 lists these pollutants.

              •      EPA performed analyses for 42 pollutants, listed in Section 3.0, Table 3-5,
                     using semiquantitative methods for "screening" purposes to determine if
                     these analytes were present. For this screening, the Agency did not use the
                     QA/QC procedures required by analytical method 1620.  EPA excluded
                     the six pollutants (strontium, potassium, platinum, sulfur, silicon, and
                     phosphorus) that passed the first three criteria but were part of the
                     screening analysis.  Based on the screening results, EPA did not measure
                     for these pollutants in a quantitative manner.

              After excluding these pollutants, EPA defined the 132 remaining pollutants as
POCs for further evaluation with respect to technology options and the performance of the
technologies. These include 47 priority pollutants (34 priority organic pollutants, 13  priority
metal pollutants), 3 conventional pollutants, and 82 nonconventional pollutants (50 organic
pollutants, 15 metal pollutants, and 17 other nonconventional pollutants).  Table 7-4 lists  these
pollutants, along with the number of times EPA analyzed for and detected each pollutant
                                           7-3

-------
                                                    7.0 - Selection of Pollutant Parameters
                              Table 7-1

Pollutants Not Detected in Any Samples Collected During the Phase I and
                 Phase II MP&M Sampling Programs
Priority Pollutants
1 ,2-Dichloropropane
1 ,3 -Dichlorobenzene
2-Chloroethylvinyl Ether
3 ,3 '-Dichlorobenzidine
4-Bromophenyl Phenyl Ether
4-Chlorophenylphenyl Ether
Acenaphthylene
Benzidine
Benzo(A)Anthracene
Benzo(A)Pyrene
Benzo(B)Fluoranthene
Benzo(Ghi)Perylene
Benzo(K)Fluoranthene
Bis(2-Chloroisopropyl) Ether
Chrysene
Dibenzo(A,H) Anthracene
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
Indeno( 1 ,2,3 -Cd)Pyrene
Pentachlorophenol
Trans- 1 ,2-Dichloroethene
Trans- 1 , 3 -Dichloropropene
Nonconventional Organic Pollutants
1,2,3 -Trichlorobenzene
1,2,3 -Trichloropropane
1,2,3 -Trimethoxybenzene
1,2,4,5-Tetrachlorobenzene
1 ,2-Dibromo-3 -Chloropropane
1 ,2-Dibromoethane
1,3 -Butadiene, 2-Chloro
1 ,3 -Dichloro-2-Propanol
1 ,3 -Dichloropropane
1,5-Naphthalenediamine
1 -Chloro-3 -Nitrobenzene
1 -Phenylnaphthalene
2,3,4,6-Tetrachlorophenol
2,3 ,6-Trichlorophenol
2,3 -Benzofluorene
2,3 -Dichloroaniline
2,3 -Dichloronitrobenzene
2,4,5-Trichlorophenol
2,6-Dichloro-4-Nitroaniline
2,6-Dichlorophenol
2-Methylbenzothioazole
Crotoxyphos
2-Nitroaniline
2-Phenylnaphthalene
2-Propen-l-Ol
2-Propenenitrile, 2-Methyl-
3 ,3 '-Dimethoxybenzidine
3,5-Dibromo 4-Hydroxybenzonitrile
3-Chloropropene
3 -Methylcholanthrene
3-Nitroaniline
4,4'-Methylenebis(2-Chloroaniline)
4,5-Methylene Phenanthrene
4-Chloro-2-Nitroaniline
5-Nitro-O-Toluidine
7, 12-Dimethylbenz(A)Anthracene
Aniline, 2,4,5-Trimethyl-
Aramite
Benzanthrone
Benzenethiol
Biphenyl, 4-Nitro
Chloroacetonitrile
Crotonaldehyde
Methyl Methanesulfonate
                                 7-4

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                                                                   7.0 - Selection of Pollutant Parameters
                                Table 7-1 (Continued)
Nonconventional Organic Pollutants (continued)
Diethyl Ether
Dimethyl Sulfone
Diphenyldisulfide
Ethyl Cyanide
Ethyl Methacrylate
Ethyl Methanesulfonate
Hexachloropropene
lodomethane
Isosafrole
Longifolene
Malachite Green
Mestranol
Methapyrilene
n-Nitrosodiethylamine
o-Toluidine, 5-Chloro-
p-Dimethylaminoazobenzene
Pentachlorobenzene
Pentachloroethane
Perylene
Phenacetin
Pronamide
Squalene
Thioacetamide
Trans-l,4-Dichloro-2-Butene
Triphenylene
Vinyl Acetate
Nonconventional Metal Pollutants
Cerium
Erbium
Europium
Gadolinium
Gallium
Germanium
Holmium
Indium
Iodine
Lanthanum
Praseodymium
Rhenium
Samarium
Scandium
Tellurium
Terbium
Thorium
Thulium
Uranium

Source: MP&M Sampling Data.
                                            7-5

-------
                                                       7.0 - Selection of Pollutant Parameters
                                 Table 7-2

         Pollutants Detected in Less Than Three Samples Collected
        During the Phase I and Phase II MP&M Sampling Programs
Priority Pollutants
1 , 1 ,2,2-Tetrachloroethane
1,1,2-Trichloroethane
1 ,2,4-Trichlorobenzene
1 ,2-Dichlorobenzene
1 ,2-Dichloroethane
1 ,2-Diphenylhydrazine
1 ,4-Dichlorobenzene
2,4-Dichlorophenol
2,4-Dinitrotoluene
2-Chloronaphthalene
2-Chlorophenol
Acrylonitrile
Bis(2-Chloroethoxy) Methane
Bis(2-Chloroethyl) Ether
Bromomethane
Nitrobenzene
n-Nitrosodi-n-Propylamine
Vinyl Chloride
Nonconventional Organic Pollutants
1,1,1 ,2-Tetrachloroethane
1 ,2 : 3 ,4-Diepoxybutane
1,3,5-Trithiane
1 ,4-Dinitrobenzene
1 ,4-Naphthoquinone
1-Naphthylamine
2,6-Di-Tert-Butyl-P-Benzoquinone
2-Picoline
4-Aminobiphenyl
Beta-Naphthylamine
Carbazole
Cis- 1 , 3 -Dichloropropene
Dibromomethane
Ethylenethiourea
n-Nitrosodi-n-Butylamine
n-Nitrosomethylphenylamine
o-Anisidine
p-Chloroaniline
Pentamethylbenzene
Phenothiazine
p-Nitroaniline
Resorcinol
Safrole
Thianaphthene
Thioxanthe -9 -One
Toluene, 2,4-Diamino-
Nonconventional Metal Pollutants
Dysprosium
Hafnium
Neodymium
Rhodium
Ruthenium
Zirconium
Source: MP&M Sampling Data.
                                    7-6

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                                                             7.0 - Selection of Pollutant Parameters
                                    Table 7-3

      Pollutants Detected at Average Concentrations of Less Than Five
          Times the Minimum Level During the Phase I and Phase II
                          MP&M Sampling Programs3
Priority Pollutants
2,4,6-Trichlorophenol
4,6-Dinitro-o-Cresol
Benzene
Bromodichloromethane
Carbon Tetrachloride (Tetrachloromethane)
Chloromethane
Dibromochloromethane
Diethyl Phthalate
Tribromomethane

Nonconventional Organic Pollutants
2-(Methylthio)Benzothiazole
n-Nitrosomethylethylamine
n-Nitrosomorpholine
o-Toluidine
Nonconventional Metal Pollutants
Bismuth
Indium
Lithium
Lutetium
Niobium
Osmium
Palladium
Tantalum
Tungsten
Ytterbium
Source: MP&M Sampling Data.
aThe average of all detected concentrations of the pollutants in samples of wastewater from proposed MP&M
operations and treatment system influent was less than five times the detection limit.
                                        7-7

-------
                                          7.0 - Selection of Pollutant Parameters
                   Table 7-4
Summary of Pollutants of Concern Information
Pollutant Parameter
Phase I and Phase II Sampling Information
No. of Times
Analyzed for All
Samples3
No. of Times
Detected for All
Samples3
Average Concentration
in Samples of Unit
Operation Wastewater
and Treatment System
Influent (mg/L)3
Priority Organic Pollutants
1,1,1 -Trichloroethane
1 , 1 -Dichloroethane
1 , 1 -Dichloroethylene
2,4-Dimethylphenol
2,4-Dinitrophenol
2,6-Dinitrotoluene
2-Nitrophenol
4-Chloro-m-cresol
4-Nitrophenol
Acenaphthene
Acrolein
Anthracene
Bis(2-Ethylhexyl) Phthalate
Benzyl Butyl Phthalate
Chlorobenzene
Chloroethane
Chloroform
Di-N-Butyl Phthalate
Di-N-Octyl Phthalate
Dimethyl Phthalate
Ethylbenzene
Fluoranthene
Fluorene
Isophorone
Methylene Chloride
n-Nitrosodimethylamine
N-Nitrosodiphenylamine
Naphthalene
1,043
1,043
1,043
994
946
1,029
1,021
1,003
969
1,029
1,003
1,029
1,028
1,026
1,043
1,043
1,043
1,026
1,028
994
1,043
1,028
1,029
996
1,043
996
1,029
1,029
28
7
3
31
4
3
9
95
5
6
5
4
211
16
7
4
331
41
18
3
61
4
18
3
52
3
15
71
0.327
0.091
0.418
0.078
83.7
2.73
0.394
260
2.99
0.332
0.307
0.117
4.15
1.08
0.282
4.22
0.049
0.352
1.58
0.739
0.165
0.132
0.956
.056
0.403
3.68
1.14
0.638
Minimum
Level
(mg/L)

0.01
0.01
0.01
0.01
0.05
0.01
0.02
0.01
0.05
0.01
0.05
0.01
0.01
0.01
0.01
0.05
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.05
0.02
0.01
                      7-8

-------
                                  7.0 - Selection of Pollutant Parameters
Table 7-4 (Continued)
Pollutant Parameter
Phase I and Phase II Sampling Information
No. of Times
Analyzed for All
Samples3
No. of Times
Detected for All
Samples3
Average Concentration
in Samples of Unit
Operation Wastewater
and Treatment System
Influent (mg/L)3
Minimum
Level
(mg/L)
Priority Organic Pollutants (continued)
Phenanthrene
Phenol
Pyrene
Tetrachloroethene
Toluene
Trichloroethylene
1,029
1,021
1,028
1,043
1,043
1,042
45
244
5
23
83
40
0.500
10.1
0.219
0.210
0.230
0.092
0.01
0.01
0.01
0.01
0.01
0.01
Priority Metal Pollutants
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc
1,956
1,972
1,972
1,972
1,972
1,972
1,972
1,970
1,972
1,956
1,972
1,956
1,971
606
627
301
873
1,480
1,752
911
321
1,518
317
698
206
1,691
6.12
0.178
0.147
244
1,029
495
30.0
0.0014
356
0.137
0.531
0.065
188
0.02
0.01
0.005
0.005
0.01
0.025
0.05
0.0002
0.04
0.005
0.01
0.01
0.02
Conventional Pollutants
BOD 5-Day (Carbonaceous)
Oil and Grease (as HEM)
Total Suspended Solids
1,005
1,028
1,959
757
554
1,563
2,015
2,308
1,007
2
5
4
Nonconventional Organic Pollutants
1,4-Dioxane
1 -Bromo-2-Chlorobenzene
1 -Bromo-3 -Chlorobenzene
1 -Methylfluorene
1 -Methylphenanthrene
2-Butanone
1,003
989
989
989
989
1,003
33
8
6
24
29
160
0.854
0.233
0.135
0.347
0.581
1.59
0.01
0.01
0.01
0.01
0.01
0.05
           7-9

-------
                                  7.0 - Selection of Pollutant Parameters
Table 7-4 (Continued)
Pollutant Parameter
Phase I and Phase II Sampling Information
No. of Times
Analyzed for All
Samples3
No. of Times
Detected for All
Samples3
Average Concentration
in Samples of Unit
Operation Wastewater
and Treatment System
Influent (mg/L)3
Minimum
Level
(mg/L)
Nonconventional Organic Pollutants (continued)
2-Hexanone
2-Isopropylnaphthalene
2-Methylnaphthalene
2-Propanone
3 ,6-Dimethylphenanthrene
4-Methyl-2-Pentanone
Acetophenone
Alpha-Terpineol
Aniline
Benzoic Acid
Benzyl Alcohol
Biphenyl
Carbon Bisulfide
Dibenzofuran
Dibenzothiophene
Diphenyl Ether
Diphenylamine
Hexanoic Acid
Isobutyl Alcohol
m+p Xylene
m-Xylene
Methyl Methacrylate
n,n-Dimethylformamide
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
n-Hexadecane
n-Nitrosopiperidine
n-Octacosane
1,003
989
989
1,003
989
1,003
989
978
989
989
989
989
1,003
989
988
989
989
989
1,003
595
408
1,003
989
989
989
989
988
989
989
989
989
7
6
61
593
13
91
10
133
19
202
61
23
63
4
6
5
14
237
19
31
21
6
63
67
108
125
156
95
168
4
40
1.26
3.21
0.775
3.14
1.24
5.19
0.159
13.6
0.684
277
1.23
0.174
0.408
0.055
0.240
0.047
0.704
15.2
0.167
0.159
0.498
0.396
0.193
2.10
3.47
13.8
3.30
5.84
6.27
0.020
7.45
0.05
0.01
0.01
0.05
0.01
0.01
0.01
0.01
0.01
0.05
0.01
0.01
0.01
0.01
0.01
0.01
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
          7-10

-------
                                  7.0 - Selection of Pollutant Parameters
Table 7-4 (Continued)
Pollutant Parameter
Phase I and Phase II Sampling Information
No. of Times
Analyzed for All
Samples3
No. of Times
Detected for All
Samples3
Average Concentration
in Samples of Unit
Operation Wastewater
and Treatment System
Influent (mg/L)3
Minimum
Level
(mg/L)
Nonconventional Organic Pollutants (continued)
n-Octadecane
n-Tetracosane
n-Tetradecane
n-Triacontane
o+p Xylene
o-Cresol
o-Xylene
p-Cresol
p-Cymene
Pyridine
Styrene
Trichlorofluoromethane
Tripropyleneglycol Methyl Ether
989
988
989
988
408
989
595
989
989
989
989
1,043
989
174
90
158
55
30
16
40
82
21
37
9
12
141
5.74
4.13
12.7
2.69
0.256
0.067
0.058
0.293
0.988
0.920
0.261
0.049
190
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Nonconventional Metal Pollutants
Aluminum
Barium
Boron
Calcium
Cobalt
Gold
Iron
Magnesium
Manganese
Molybdenum
Sodium
Tin
Titanium
Vanadium
Yttrium
1,972
1,972
1,913
1,972
1,972
161
1,972
1,972
1,972
1,972
1,972
1,912
1,913
1,972
1,913
1,520
1,651
1,645
1,929
640
104
1,743
1,803
1,620
1,091
1,953
850
949
504
306
166
1.75
85.0
68.4
12.8
16.2
777
53.8
43.4
2.97
3,384
153
32.6
5.31
0.061
0.2
0.2
0.1
5
0.05
1
0.1
5
0.015
0.01
5
0.03
0.005
0.05
0.005
          7-11

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                                                                  7.0 - Selection of Pollutant Parameters
                                Table 7-4 (Continued)
Pollutant Parameter
Phase I and Phase II Sampling Information
No. of Times
Analyzed for All
Samples3
No. of Times
Detected for All
Samples3
Average Concentration
in Samples of Unit
Operation Wastewater
and Treatment System
Influent (mg/L)3
Minimum
Level
(mg/L)
Other Nonconventional Pollutants
Amenable Cyanide
Ammonia As Nitrogen
Chemical Oxygen Demand (COD)
Chloride
Fluoride
Hexavalent Chromium
Sulfate
Total Cyanide
Total Dissolved Solids
Total Kjeldahl Nitrogen
Total Organic Carbon (TOC)
Total Petroleum Hydrocarbons
(as SGT-HEM)
Total Phosphorus
Total Recoverable Phenolics
Total Sulfide
Weak-Acid Dissociable Cyanide
Ziram
160
689
1,461
677
688
1,074
1,171
406
1,953
661
997
1,016
500
1,357
215
72
31
128
569
1,343
631
618
268
1,086
327
1,948
572
838
350
452
871
80
62
22
44.3
385
11,289
5,526
301
1.78
7,046
2,072
21,883
606
3,385
841
170
11.7
6.50
19.4
1.41
0.02
0.05
5
1
0.1
0.01
1
0.02
10
1
1
5
0.01
0.05
1
0.002
0.01
Source: MP&M Sampling Data.
aCounts and average based on Phase I and Phase II sampling results. Sample concentrations less than the ML were
not included in the average.

parameter in samples of the unit operation wastewater or treatment system influent. Table 7-4
also presents the average concentration at which each pollutant was detected. The Agency did
not use sample concentrations reported as less than the ML in calculating the average.
7.2
Regulated Pollutants
              EPA determined the pollutants for potential regulation on a subcategory basis.
As a first step in selecting the pollutants, the Agency grouped the proposed MP&M subcategories
(discussed in Section 6.0) according to whether the facilities in the proposed subcategory
generated wastewater with high metals content (metal-bearing) or wastewater with low metals
content and high oil and grease content (oil-bearing). The proposed General Metals, Metal
Finishing Job Shops, Printed Wiring Board, Non-Chromium Anodizing, and Steel Forming and
Finishing Subcategories generate metal-bearing wastewaters, while the Oily Wastes Subcategory
                                           7-12

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                                                                 7.0 - Selection of Pollutant Parameters

and the proposed Railroad Line Maintenance and Shipbuilding Dry Dock Subcategories generate
only oil-bearing wastewaters.

              Then, EPA evaluated the concentrations and prevalence of the POCs in the unit
operations (baths and rinses) and treatment system influents for each subcategory. EPA also
evaluated the effectiveness of the selected treatment technologies for each option (see Section
9.0) to determine which pollutants were effectively removed by these technologies.  Using this
information, EPA considered the following factors in determining which pollutants should not be
further considered for regulation:

              •      The pollutant is controlled through the regulation of other pollutants.  EPA
                    evaluated wastewater treatment data to determine if control of one
                    parameter would also control other pollutants. For example, most metal
                    POCs are effectively removed by chemical precipitation. Control of the
                    metals predominantly detected in process wastewater from proposed
                    MP&M operations also controls those other metals not as common in
                    process wastewater from proposed MP&M operations. Therefore, EPA
                    considered only a subset of metals for regulation. In addition, many
                    organic pollutants detected in process wastewater from proposed MP&M
                    operations are removed in oil/water separation systems in the oil phase of
                    the wastewater. Therefore, controlling the oil and grease bulk parameter
                    effectively controls these organic pollutants.

              •      The pollutant is present in only trace amounts in the subcategory's
                    wastewater type (metal-bearing or oil-bearing) and/or is not likely to cause
                    toxic effects. EPA performed this evaluation on a pollutant-by-pollutant
                    basis using the data presented in Section 5.0.

              •      The pollutant may be used as a treatment chemical.

              •      The pollutant is not controlled by the selected BPT/BAT technologies.
                    EPA  reviewed the treatment data for technologies considered in the
                    MP&M technology options (see Section 9.0), and identified any pollutants
                    that were not effectively removed by these technologies.

              Based on these criteria, a number of these pollutants were not further considered
for regulation. Based on other factors, EPA established limitations and standards for direct
dischargers in the Oily Wastes  Subcategory only. For that subcategory, the list of remaining
POCs was reduced for the purpose of setting limitations and standards to oil and grease (as
HEM) and TSS.  Table 7-5 lists all of the remaining POCs and the reason each pollutant was
eliminated.

              EPA determined that regulating only oil and grease will control the removal of
organic constituents for the  Oily Wastes Subcategory.  EPA did not promulgate a limit for total

                                          7-13

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                                                                7.0 - Selection of Pollutant Parameters

petroleum hydrocarbons (TPH) (as SGT-HEM) because it believes that regulating oil and grease
(as HEM) will control the discharge of TPH (as SGT-HEM).

              EPA determined that it was not necessary to promulgate limits for 28 POCs that
are present in only trace amounts in the Oily Wastes Subcategory and/or are not likely to cause
toxic effects.  As shown in Table 5-4, the median concentration at the influent to treatment for
most of these metals is less than 0.5 mg/L.

              EPA did not select aluminum, calcium, iron, magnesium, manganese, sodium,
chloride, sulfate, or total sulfide for regulation in the Oily Wastes Subcategory because they may
be used as treatment chemicals by facilities in the Oily Wastes Subcategory.

              EPA did not select lead, zinc, barium, boron or total phosphorus for regulation in
the Oily Wastes Subcategory because they are not controlled by the selected BPT/B AT
technology.

7.3           References

1.             U.S. Environmental Protection Agency.  The 1990 Industrial Technology Division
              List of Analvtes. Washington, DC, May  1990.

2.             U.S. Environmental Protection Agency.  Development Document for Final
              Effluent Limitations Guidelines and  Standards for the Centralized Waste
              Treatment Industry. (EPA-821-R-00-020), 2000.
                                          7-14

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                                                       7.0 - Selection of Pollutant Parameters
                               Table 7-5

Pollutants Considered for Regulation for Direct Dischargers in the Oily
                          Wastes Subcategory
Pollutant Parameter
Controlled
Through
Regulation of
Other
Pollutants
Present in
Trace
Amounts or
Not Likely to
Cause Toxic
Effects
Treatment
Chemical
Not Controlled
by BPT/BAT
Technology
Regulated
Under 40 CFR
438
Priority Organic Pollutants
1,1,1 -Trichloroethane
1 , 1 -Dichloroethane
1 , 1 -Dichloroethylene
2,4-Dimethylphenol
2,4-Dinitrophenol
2,6-Dinitrotoluene
2-Nitrophenol
4-Chloro-m-cresol
4-Nitrophenol
Acenaphthene
Acrolein
Anthracene
Bis(2-Ethylhexyl) Phthalate
Benzyl Butyl Phthalate
Chlorobenzene
Chloroethane
Chloroform
Di-N-Butyl Phthalate
Di-N-Octyl Phthalate
Dimethyl Phthalate
Ethylbenzene
Fluoranthene
Fluorene
Isophorone
Methylene Chloride
n-Nitrosodimethylamine
N-Nitrosodiphenylamine
Naphthalene
Phenanthrene
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/




















































































































                                  7-15

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Table 7-5 (Continued)
                                  7.0 - Selection of Pollutant Parameters
Pollutant Parameter
Controlled
Through
Regulation of
Other
Pollutants
Present in
Trace
Amounts or
Not Likely to
Cause Toxic
Effects
Treatment
Chemical
Not Controlled
by BPT/BAT
Technology
Regulated
Under 40 CFR
438
Priority Organic Pollutants (continued)
Phenol
Pyrene
Tetrachloroethene
Toluene
Trichloroethylene
/
/
/
/
/




















Priority Metal Pollutants
Antimony
Arsenic
Beryllium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Thallium
Zinc













/
/
/
/
/
/

/
/
/
/
/




















/





/













Conventional Pollutants
BOD 5-Day (Carbonaceous)
Oil and Grease (as HEM)
Total Suspended Solids
/












/
/
Nonconventional Organic Pollutants
1 ,4-Dioxane
1 -Bromo-2-Chlorobenzene
1 -Bromo-3-Chlorobenzene
1-Methylfluorene
1 -Methylphenanthrene
2-Butanone
2-Hexanone
2-Isopropylnaphthalene
2-Methylnaphthalene
2-Propanone
/
/
/
/
/
/
/
/
/
/








































          7-16

-------
Table 7-5 (Continued)
                                  7.0 - Selection of Pollutant Parameters
Pollutant Parameter
Controlled
Through
Regulation of
Other
Pollutants
Present in
Trace
Amounts or
Not Likely to
Cause Toxic
Effects
Treatment
Chemical
Not Controlled
by BPT/BAT
Technology
Regulated
Under 40 CFR
438
Nonconventional Organic Pollutants (continued)
3 ,6-Dimethylphenanthrene
4-Methyl-2-Pentanone
Acetophenone
Alpha- Terpineol
Aniline
Benzoic Acid
Benzyl Alcohol
Biphenyl
Carbon Bisulfide
Dibenzofuran
Dibenzothiophene
Diphenyl Ether
Diphenylamine
Hexanoic Acid
Isobutyl Alcohol
m+p Xylene
m-Xylene
Methyl Methacrylate
n,n-Dimethylformamide
n-Decane
n-Docosane
n-Dodecane
n-Eicosane
n-Hexacosane
n-Hexadecane
n-Nitro sopiperidine
n-Octacosane
n-Octadecane
n-Tetracosane
n-Tetradecane
n-Triacontane
o+p Xylene
o-Cresol
o-Xylene
/
/
/
/
/
/
/
/

/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/








/































































































































          7-17

-------
Table 7-5 (Continued)
                                  7.0 - Selection of Pollutant Parameters
Pollutant Parameter
Controlled
Through
Regulation of
Other
Pollutants
Present in
Trace
Amounts or
Not Likely to
Cause Toxic
Effects
Treatment
Chemical
Not Controlled
by BPT/BAT
Technology
Regulated
Under 40 CFR
438
Nonconventional Organic Pollutants (continued)
p-Cresol
p-Cymene
Pyridine
Styrene
Trichlorofluoromethane
Tripropyleneglycol Methyl Ether
/
/
/
/
/
/
























Nonconventional Metal Pollutants
Aluminum
Barium
Boron
Calcium
Cobalt
Gold
Iron
Magnesium
Manganese
Molybdenum
Sodium
Tin
Titanium
Vanadium
Yttrium



















/
/



/

/
/
/
/
/


/


/
/
/

/





/
/



























Other Nonconventional Pollutants
Amenable Cyanide
Ammonia As Nitrogen
Chemical Oxygen Demand
(COD)
Chloride
Fluoride
Hexavalent Chromium
Sulfate
Total Cyanide
Total Dissolved Solids
Total Kjeldahl Nitrogen


/







/
/


/
/

/
/
/



/


/























          7-18

-------
                                  7.0 - Selection of Pollutant Parameters
Table 7-5 (Continued)
Pollutant Parameter
Controlled
Through
Regulation of
Other
Pollutants
Present in
Trace
Amounts or
Not Likely to
Cause Toxic
Effects
Treatment
Chemical
Not Controlled
by BPT/BAT
Technology
Regulated
Under 40 CFR
438
Other Nonconventional Pollutants (continued)
Total Organic Carbon (TOC)
Total Petroleum Hydrocarbons
(as SGT-HEM)
Total Phosphorus
Total Recoverable Phenolics
Total Sulfide
Weak-Acid Dissociable Cyanide
Ziram
/
/

/








/
/




/




/











          7-19

-------
                                               8.0 - Pollution Prevention and Wastewater Treatment Technologies

8.0           POLLUTION PREVENTION PRACTICES AND WASTEWATER
              TREATMENT TECHNOLOGIES

              In general, MP&M facilities generate process wastewater containing metals,
cyanide, oil and grease, and suspended solids. Pollution prevention practices and wastewater
treatment technologies currently used by facilities evaluated for the final rule ("MP&M
facilities") are designed to remove these pollutants before they are discharged to either a
receiving stream (direct discharge) or public owned treatment works  (indirect discharge). The
type of pollution prevention practice and wastewater treatment technology a MP&M facility
selects depends on the manufacturing operations generating the wastewater. Many facilities have
implemented process modifications for waste reduction. Some of those modifications include
prolonging process bath life by removing contaminants, redesigning part racks to reduce dragout,
installing spray or fog nozzle rinse systems, and installing dragout recovery tanks (1).

              Most MP&M facilities rely on chemical  precipitation and gravity or membrane
clarification to remove metals; however, certain pretreatment techniques may be necessary when
chelated metals or hexavalent chromium are present. Facilities that generate oily wastewater
from operations such as machining and grinding typically use chemical emulsion breaking
followed by gravity or membrane clarification.  If cyanide is present, facilities typically use
oxidation techniques such as alkaline chlorination.

              This section describes the pollution prevention practices and wastewater treatment
technologies that are used by MP&M facilities, in the first instance, to prevent the generation of
wastewater pollutants or,  secondarily, to reduce the discharge of wastewater pollutants.  Section
8.1 describes flow reduction practices,  Section 8.2 describes in-process pollution prevention
technologies, Section 8.3  describes management practices for pollution prevention, Section 8.4
describes technologies used for the preliminary treatment of waste streams, and Section 8.5
describes end-of-pipe wastewater treatment and sludge  dewatering technologies.  This section
discusses the most prevalent treatment technologies, as  determined by survey responses and site
visits, in place at facilities evaluated for the final rule. This section includes descriptions of all
the technologies evaluated for the final rule and used as a basis for the MP&M effluent
guidelines (see Section 9.0).  Additional technologies may be applicable for some MP&M
facilities, depending on the waste streams generated.  Additionally, not all technologies discussed
in this section are applicable to all MP&M facilities; the applicability of a technology is driven
by the unit operations performed and waste streams generated on-site. EPA presents pollution
prevention practices and wastewater treatment information potentially applicable to all facilities
evaluated for the final rule ("MP&M facilities").

8.1           Flow Reduction Practices

              MP&M facilities applies flow reduction  practices to process baths or rinses to
reduce the volume of wastewater discharged. Flow reduction practices consist of optimizing
rinse tank design and configuration, and installing flow reduction technologies such as flow
restrictors or timers.  Table 8-1  lists various flow reduction practices and the number

                                           8-1

-------
                                                 8.0 - Pollution Prevention and Wastewater Treatment Technologies

observations at EPA MP&M site visits and surveys (see Section 3.0). This table also provides
EPA's estimate of the number of MP&M facilities employing the various flow reduction
practices based on occurrence at surveyed facilities and their respective survey weights. The
following subsections discuss these flow reduction practices in greater detail.

8.1.1          Rinse Tank Design and Innovative Configurations

              Rinsing follows many proposed MP&M operations1 to remove dirt, oil, or
chemicals remaining on parts or racks from a previous unit operation (i.e., drag-out). Rinsing
improves the quality of the surface finishing process and prevents the contamination of
subsequent process baths. Rinse tank design and rinsing configuration greatly influence water
usage. The key objectives of optimal rinse tank design are to quickly remove drag-out solution
from the part and to disperse the drag-out throughout the rinse tank.
MP&M facilities uses various rinsing configurations.  The most common are countercurrent
cascade rinsing, drag-out rinsing, and spray rinsing. EPA  estimates that over 5,000 MP&M
facilities use at least one of these rinse schemes to reduce wastewater flow. The use  of single
overflow rinse tanks following each process tank is the most inefficient use of rinse water.
Multiple rinse tanks connected in series (i.e., cascade rinsing) reduce 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 quality).  Spray rinsing, where the part is suspended over a tank and rinsed with
water applied by spray nozzles, also may be used to reduce water use requirements, although less
than countercurrent cascade rinses.  Below are descriptions of some of the common rinse types.

              Cascade Rinsing

              Cascade rinsing is a method of reusing water from one rinsing operation to
another, less critical rinsing operation before being discharged to treatment.  Some rinse waters
acquire chemical properties, such as low pH, that make them desirable for reuse in other rinse
systems.  For example, water from an acid treatment rinse may be reused in an alkaline treatment
rinse.  In this case, the rinse water both removes  drag-out from the work piece and neutralizes the
drag-out.
'Note: EPA evaluated a number of unit operations for the May 1995 proposal, January 2001 proposal, and June 2002
NODA (see Tables 4-3 and 4-4). However, EPA selected a subset of these unit operations for regulation in the final
rule (see Section 1.0). For this Section, the term "proposed MP&M operations" means those operations evaluated for
the two proposals, NODA, and final rule. The term "final MP&M operations" means those operations defined as
"oily operations" (see Section 1.0, 40 CFR 438.2(f), and Appendix B to Part 438) and regulated by the final rule.

                                            8-2

-------
                                                                                       8.0 - Pollution Prevention and Wastewater Treatment Technologies
                                                             Table 8-1
                                             MP&M Flow Reduction Technologies
Technology
Countercurrent Cascade
Rinsing
Drag-Out Rinsing
Spray Rinsing
Flow Restrictors
Technology Description
Series of consecutive rinse tanks that 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 has the
highest concentration of pollutants.
Stagnant rinse, initially of fresh water, positioned immediately after
process tanks. The drag-out rinse collects most of the drag-out from
the process tank, preventing it from entering the subsequent flowing
rinses. Drag-out rinse is commonly reused as make-up for heated
process bath to replace evaporative loss.
Water sprayed on parts above a process tank or drip/drag-out tank;
uses considerably less water than immersion for certain part
configurations. This technology can also be performed as
countercurrent cascade rinsing with spray rinses instead of overflow
immersion rinses.
Equipment that prevents the flow in a pipe from exceeding a
predetermined flow rate. 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.
Demonstration Status
Number of
Facilities
Visited Using
the Technology3
110
62
75
50
Number of
Survey
Facilities
Using the
Technology1"
130
139
187
127
Estimated Number
of MP&M
Facilities Using the
Technology0
1,569
1,737
1,767
1,581
oo

-------
                                                                       Table 8-1 (Continued)
                                                                                                                      8.0 -  Pollution Prevention and Wastewater Treatment Technologies
Technology
Conductivity Probes
Technology Description
Equipment that measures 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.
Demonstration Status
Number of
Facilities
Visited Using
the Technology3
40
Number of
Survey
Facilities
Using the
Technology"
29
Estimated Number
ofMP&M
Facilities Using the
Technology0
320
Source:  MP&M site visits, MP&M sampling episodes, MP&M surveys and technical literature.  Statistics specific to waste water-discharging facilities.
'Indicates the number of MP&M facilities visited by EPA that use the listed technology.  EPA visited a total of 221 facilities.
bNumberof survey facilities based on data collected in 1996 detailed survey only. The 1989 survey did not request this information.  EPA sent the 1996 detailed survey to 311 facilities.
"Indicates the estimated number of MP&M facilities currently performing this technology based on the 1996 detailed survey. EPA's national estimate of the 1996 detailed survey includes
approximately 4,900 facilities. EPA estimated numbers in this column using statistical weighting factors for the 1996 detailed survey respondents. See Section 3.0 for a discussion of the development
of national estimates and statistical survey weights.

-------
                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

              Countercurrent Cascade Rinsing

              Countercurrent cascade rinsing refers to a series of consecutive rinse tanks that are
plumbed to cause water to flow from one tank to another in the direction opposite of the work
flow. Fresh water flows into the rinse tank located farthest from the process tank and overflows
(i.e., cascades) into the rinse tank that is closest to the process tank. This is called Countercurrent
rinsing because the work piece and the rinse water move in opposite directions.  Over time, the
first rinse becomes contaminated with drag-out solutions and reaches a stable concentration of
process bath constituents that is lower than the concentration in the process bath. 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 rinse water is needed to adequately remove the process solution. This differs
from a single, overflow rinse tank where the rinse water is composed of fresh water that is
discharged after use without any recycle or reuse. Figure 8-1 illustrates Countercurrent cascade
rinsing.
       work movement »- —
                                                                            incoming water
                       Figure 8-1.  Countercurrent Cascade Rinsing
              The rinse rate needed to adequately dilute drag-out depends on the concentration
of process chemicals in the initial process bath, the concentration of chemicals that can be
tolerated in the final rinse tank to meet product specifications, the amount of drag-out solution
carried into each rinse stage, and the number of Countercurrent cascade rinse tanks.  These factors
are expressed in Equation 8-1 (2):
                                     1/n
                                           'D
                                                                                   (8-1)
                                            8-5

-------
                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

where:

              Vr     =      the flow rate 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 rate,
                            gal/min.

              This mathematical rinsing model is based on complete rinsing (i.e., removal of all
contaminants from the work piece) and complete mixing (i.e., homogeneous rinse water in each
rinse stage). Under these conditions, each additional rinse stage can reduce rinse water use by 90
percent. However, each rinse stage needs to have sufficient residence time and agitation for
complete mixing to occur in each rinse tank to achieve these conditions. For less efficient rinse
systems, each added rinse stage reduces rinse water use by 50 to 75 percent.

              Countercurrent cascade rinsing systems have higher capital costs than do overflow
rinses and require more space to accommodate the additional rinse tanks. 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 may be
added to increase rinsing efficiency.

              Drag-out Rinsing

              Drag-out rinse is a stagnant rinse, initially filled with fresh water, positioned
immediately after the process tank. Work pieces are rinsed in drag-out tanks directly after
exiting the process bath. The drag-out rinse collects most of the drag-out from the process tank,
thus preventing it from entering the subsequent flowing rinses and reducing pollutant loadings in
those rinses. Gradually, the concentration of process chemicals in the drag-out tank rises.  In the
most efficient configuration, a drag-out tank follows a heated process tank that has a moderate to
high evaporation rate. A portion of the fluid in the drag-out tank returns to the process tank to
replace the evaporative loss. The level of fluid in the drag-out tank is maintained by adding fresh
water.  Electrolytic recovery, discussed in Section  8.2.6, is commonly used to remove dissolved
metals from drag-out tanks.

              Spray Rinsing

              For certain work piece configurations, spray rinsing uses considerably less water
than does immersion rinsing.  During spray rinsing, the parts are held over a catch tank and are
sprayed with water. Water then drips from the part into the catch tank, and is then either recycled
to the next stage or discharged to treatment. Spray rinsing can occur in a countercurrent cascade
configuration, further reducing water use. Spray rinsing can enhance draining over a process
                                            8-6

-------
                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

bath by diluting and lowering the viscosity of the process fluid film clinging to the work piece.
Using spray rinsing can control rinse water flow.

8.1.2         Additional Design Elements

              In addition to rinse configuration, unit operations can be modified in other ways to
reduce drag-out of process bath chemicals. For example, air knives and drip tanks reduce the
pollutant loading and volume of rinse water requiring treatment. Other aspects of good rinse
tank design include positioning the water inlet and discharge points of the tank at opposite
locations in the tank to avoid short-circuiting, using air agitation for better mixing, using a flow
distributor, and using the minimum tank size possible (3). Four rinse design elements are
described in more detail below.

              Air Knives

              Air knives are high-pressure air blowers installed over a process tank or drip
shield and are designed to remove drag-out by blowing the liquid off the surface of work pieces
and racks and into a catch tank. Liquid from the catch tank is pumped back to the process tank.
Air knives  are most effective with flat parts and cannot be used to dry surfaces that passivate or
stain due to oxidation.

              Drip Shields

              Drip shields are inclined sheets installed between process tanks and rinse tanks to
recover, and drain to the process tank, process fluid that drips from racks and barrels and would
otherwise fall into rinse tanks or onto the floor.  Often, drip shields are composed of
polypropylene or another inert material.

              Drip Tanks

              Drip tanks are installed immediately after the process tank. Work pieces exiting a
process bath are  held over the drip tank and the process fluid that drips from the work pieces
collects in the drip tank.  When enough fluid is collected in the  drip tank, the fluid flows back to
the process tank.

              Long Dwell Time

              Automatic finishing lines can be programmed to include  optimum drip times.
Long dwell times over the process tank reduce the volume of drag-out reaching the rinsing
system. On manual lines, racks can be hung on bars over process baths to allow the fluid  drip.
Barrels can be rotated over the process bath to enhance drainage. Increases in drip time may be
unsuitable for surfaces that  can be oxidized or stained by exposure to air.
                                           8-7

-------
                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

8.1.3         Rinse Water Use Control

              Facilities can reduce water use by coordinating and closely monitoring rinse water
requirements (e.g., rinse water use is optimized based on drag-out rates so that the rinse quality is
consistent).  Matching water use to rinse water requirements optimizes the quantity of rinse water
used for a given work load and tank arrangement (3). Inadequate controlling water use negates
the benefits  of using multiple rinse tanks or other water conservation practices and results in a
high water usage.

              Many facilities use  some form of rinse water control. The four most common
methods are flow restrictors (these can be used 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.  Using data from the 1996 MP&M industry survey, EPA
estimates there are over 1,900 MP&M facilities using this equipment to control rinse water flow.
These are  discussed below.

              Flow Restrictors

              A flow restrictor prevents the flow in a pipe from exceeding a predetermined flow
rate. Flow restrictors are commonly installed on a rinse tank's water inlet.  These  devices contain
an elastomer washer that 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
and is therefore best suited for continuous rinsing. 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 use control.

              Conductivity Controllers

              Conductivity controllers use conductivity probes to measure the conductivity
(total dissolved solids (TDS)) of water in a rinse tank to regulate the flow of fresh  rinse water
into the rinse system. 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 enter the water in the rinse tank, raising the conductivity of the water. When
conductivity reaches a set point where the water can no longer provide effective rinsing, the
solenoid valve opens to allow fresh water to enter the tank.  When the conductivity falls below
the set point, the valve closes to discontinue the fresh water flow.

              In theory,  conductivity control of rinse flow is a precise method of maintaining
optimum rinsing conditions in intermittent rinsing operations. In practice, conductivity
controllers work best with deionized rinse water.  Incoming fresh water conductivity may vary
day to day and season to season, which forces frequent set point adjustments.  In addition,

-------
                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

suspended solids and nonionic contaminants (e.g., oil) can cause inadequate rinsing and are not
measured by the conductivity probe.

              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 predetermined time period,
usually from 1 to 99 minutes. After the time period has expired, the valve automatically closes.
The timer may be activated either manually by the operator or automatically by the action of
racks or hoists. Automatic rinse timers are generally preferred for intermittent rinses because
they eliminate operator error. 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) because the rinse  operates nearly continuously.

8.1.4         Pollution Prevention for Process Baths

              Facilities also can implement measures that will reduce or prevent pollution in
process baths to reduce the drag-out pollutant loadings and therefore the amount of drag-out
solution produced.  Examples of these technologies are increasing bath temperature, operating at
lower batch concentration, and using wetting agents, discussed below:

              •      Temperature and viscosity are inversely related; therefore, operating a bath
                     at the  highest possible temperature will lower process bath viscosity and
                     reduce drag-out.

              •      Operating at the lowest possible concentration reduces the mass of
                     chemicals in a given volume of drag-out.  Also, viscosity and
                     concentration are directly related; therefore, lower process bath
                     concentration will result in lower process bath viscosity and less drag-out
                     volume. Contaminants and other process bath impurities should be
                     minimized, if possible, to extend the usefulness  of the bath, reducing the
                     frequency of treatment or disposal.

              •      Adding wetting agents or surfactants to some process baths reduces
                     viscosity and surface tension, thereby significantly reducing drag-out.

8.2           In-Process Pollution Prevention Technologies

              This section describes in-process pollution prevention technologies used at
MP&M facilities to reduce pollutant loadings to the wastewater treatment system. Table 8-2 lists
a number of in-process pollutant prevention technologies. This table also provides EPA's
estimate of the number of MP&M facilities employing the various in-process pollutant
                                            8-9

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                                                                                      8.0 - Pollution Prevention and Wastewater Treatment Technologies
                                                             Table 8-2
                                    MP&M In-Process Pollution Prevention Technologies
Technology
Evaporation with
Condensate Recovery
Ion Exchange (in-
process)
Reverse Osmosis
Centrifugation of
Painting Water
Curtains
Filtration of Painting
Water Curtains
Settling of Painting
Water Curtains
Biocide Addition to
Lengthen Coolant Life
Centrifugation of
Machinery Coolant
Technology Description
Removes water by evaporation, leaving a concentrated residue for
disposal and water vapor for condensation and reuse.
Removes metal salts from electroplating rinse water using combined
cation and anion exchange. Effluent (permeate) from the ion
exchange flows back to the electroplating rinse system. Ion
exchange regenerants are either discharged to the end-of-pipe
chemical precipitation unit for metals removal or to electrolytic
recovery for metals recovery.
Forces wastewater through a membrane at high pressure, leaving a
concentrated stream of pollutants for disposal. Reverse osmosis may
provide an effluent clean enough for reuse.
Removes the heavier solids from the water curtain by Centrifugation,
allowing the water to be reused. The solids are collected as a cake in
the basket of the centrifuge. This technology can achieve closed-loop
reuse of water curtains.
Removes solids by filtration (cloth, sand, diatomaceous earth, etc.)
followed by reuse. This technology can achieve closed-loop reuse of
water curtains.
Removes the heavier solids from the water curtains by gravity
separation. This technology can be used in conjunction with other
removal technologies to lessen the solids loading.
Can impede the growth of microorganisms that cause rancidity.
Machining coolant is often discarded as it becomes rancid.
Removes the solids from the coolant by Centrifugation to extend its
usable life. Some high-speed centrifuges can also perform liquid-liquid
separation to remove tramp oils and further extend coolant life.
Demonstration Status
Number of
Facilities Visited
Using the
Technology3
7
35
3
3
2
5
9
18
Number of
Survey
Facilities
Using the
Technology"
15
33
1
1
3
5
27
10
Estimated Number
of MP&M
Facilities Using the
Technology0
147
437
3
12
20
23
216
78
oo
o

-------
                                                                               Table 8-2 (Continued)
                                                                                                                              8.0 - Pollution Prevention and Wastewater Treatment Technologies
Technology
Filtration of Machinery
Coolant
Skimming of Tramp
Oils in Machinery
Coolants
Pasteurization of
Machinery Coolants
General Filtration of
Baths and Solutions
Electrolytic Recovery
(Electrowinning)
Technology Description
Removes the solids from the coolant using filters such as cloth, sand, or
carbon to extend its usable life.
Removes tramp oils using mechanical skimming to extend coolant
life. Tramp oil buildup often makes machining coolant unusable.
Kills the microorganisms that cause rancidity using heat. Machining
coolant is often discarded as it becomes rancid.
Removes metals and other impurities from process tanks, including
electrolytic plating solutions and acid/alkaline cleaning tanks.
Increases bath longevity. Technologies include paper filters, carbon
adsorption, and magnetic separators.
Recovers dissolved metals from concentrated sources using an
electrochemical process. For rinses, electrolytic recovery is typically
restricted to drag-out rinses. Flowing rinses are generally too dilute
for efficient electrolytic recovery. This technology effectively
recovers metals from ion exchange regenerants.
Demonstration Status
Number of
Facilities Visited
Using the
Technology3
18
8
2
6
22
Number of
Survey
Facilities
Using the
Technology"
18
9
2

23
Estimated Number
ofMP&M
Facilities Using the
Technology0
142
82
18

142
oo
         Source: MP&M site visits, MP&M sampling episodes, MP&M surveys and technical literature. Statistics specific to waste water-discharging facilities.
         "Indicates the number of MP&M facilities visited by EPA that use the listed technology. EPA visited a total of 221 facilities.
         bNumberof survey facilities based on data collected in 1996 detailed survey only.  The 1989 survey did not request this information. EPA sent the 1996 detailed survey to 311 facilities.
         "Indicates the estimated number of MP&M facilities currently performing this technology based on the 1996 detailed survey. EPA's national estimate of the 1996 detailed survey includes
         approximately 4,900 facilities.  EPA estimated numbers in this column using statistical weighting factors for the 1996 detailed survey respondents. See Section 3.0 for a discussion of the development
         of national estimates and statistical survey weights.

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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

prevention technologies based on occurrence at surveyed facilities and their respective survey
weights. In-process pollution prevention technologies can be applied to process baths or rinses.
Not all technologies discussed in this subsection are applicable to all MP&M facilities.

              Process baths become contaminated with impurities that affect their performance.
The sources of process bath contamination include: (1) breakdown of process chemicals;
(2) buildup of by-products (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 not
properly maintained, process baths become prematurely unusable and require disposal.
Regeneration and maintenance techniques help keep baths in good operating condition, thereby
extending the useful lives of process solutions. Using these technologies reduces the frequency
of process bath discharges, and therefore reduces pollutant loadings to the wastewater treatment
system. This, in turn, reduces wastewater treatment requirements and sludge disposal costs.

              Rinsing removes residual process chemicals from the  surface of a work piece. As
more and more work pieces are rinsed, the concentration of process chemicals (contaminants) in
the rinse water increases. At some point, the concentration of process chemicals in the rinse
water becomes so high that an unacceptable amount of process chemicals remain on the surface
of the work piece.  When this occurs, clean water is added to the rinse solution to lower the
concentration of process chemicals to a level that will not impact the quality of the work piece.
Overflow from the rinsing operation goes to treatment for removal of the residual process
chemicals. For continuous processing operations, clean water may continuously flow into the
rinse process to ensure that the concentration of contaminants will not exceed the quality limit
for the work piece.

              This section describes the following technologies used to treat and reuse process
solutions:

              •      Activated carbon adsorption;
              •      Carbonate freezing;
              •      Centrifugation and pasteurization of machining coolants;
              •      Centrifugation and recycling of painting water curtains;
              •      Electrodialysis;
              •      Electrolytic recovery;
              •      Evaporation;
              •      Filtration;
              •      Ion exchange; and
              •      Reverse osmosis.

8.2.1          Activated Carbon Adsorption

              Activated carbon adsorption is a common method of removing organic
contaminants from electroplating baths.  Process solution flows through a filter where the carbon
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adsorbs organic impurities that result from the breakdown of bath constituents.  Carbon
adsorption can be either a continuous or batch operation, depending on the site's preference.
Carbon treatment is most commonly applied to nickel, copper, zinc, and cadmium electroplating
baths but also can be used to remove organic contaminants from paint curtains.

8.2.2         Carbonate "Freezing"

              Carbonate "freezing" removes excessive carbonate buildup by forming carbonate
salt crystals at a low temperature that are then removed.  MP&M facilities most often apply this
process to electroplating baths formulated with sodium cyanide. Carbonates build up in the
process bath by the breakdown of cyanide (especially at high temperatures) and the adsorption of
carbon dioxide from the air.  An excessive carbonate concentration reduces the product quality of
many metal finishing operations. Carbonate "freezing" takes advantage of the low solubility of
carbonate salts in the sodium cyanide bath. The method lowers the bath temperature to
approximately 26°F (-3°C), at which point hydrated salt (Na2CO3»10H2O) crystallizes out of
solution. The crystallized carbonate can be removed by decanting the fluid into another tank or
by filtration.

8.2.3         Centrifugation and Pasteurization of Machining Coolants

              Most machining coolants contain water-soluble oil in water. The water-soluble
coolant typically is pumped from a sump, over the machining tool and work piece during
machining, and back to the sump. Over a period of time, recycled coolant becomes ineffective,
or 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,
                     inhibiting performance;

              •       The coolant becomes rancid due to microbial growth; or

              •       Coolant additives are consumed by drag-out and organic breakdown, thus
                     reducing corrosion prevention and lubrication properties.

As shown in Table 8-2, EPA estimates that nearly 300 MP&M facilities use centrifugation and
biocide/pasteurization processes to extend the life of their water-soluble coolants.

              Coolant recycling is most effective when facilities minimize the number of
different coolants used on-site and use  a centralized coolant recycling system. However, some
facilities may not be able to use a single recycling system because of multiple coolant types
required by product or customer specifications.  In this case, facilities may need to purchase
dedicated coolant recycling systems for each type of coolant used.
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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

              Using a centrifugal separator and pasteurization unit can extend the useful life of
machining coolants.  The separator is a rotating chamber that uses centrifugal force to push the
coolant through a mesh chamber, leaving behind solid contaminants of sludge.  Sludge is scraped
from the centrifuge and collected in a sludge hopper.  Some high-speed centrifuges also can
perform liquid-liquid separation to remove tramp oils. The coolant undergoes pasteurization
after separation to kill the microorganisms that cause bacterial growth. Adding a biocide can
also control bacterial growth. Figure 8-2 shows a diagram of a typical  machine coolant recycling
system.
                                                                       Recycled Coolant
                                                                        Holding Tank
                      Figure 8-2.  Machine Coolant Recycling System

              Centrifugal separators are very reliable and require only routine maintenance, such
as periodic cleaning and removal of accumulated solids.  Flow rate is the primary operating
factor to control.  The sludge generated from this technology is commonly classified as a
hazardous waste,  based on the metal type processed and the amount of metal that dissolves into
the coolant. Facilities typically haul the sludge off-site for treatment and disposal.

              Centrifugation and pasteurization can be used in conjunction with oil skimming
and biocide addition to reduce coolant discharge and pollutant generation at the source.  Oil
skimming using a vertical belt system (described in Section 8.4.5.2) removes large amounts of
tramp hydraulic oils floating on the surface of the machine coolant.  Oil skimming and biocide
addition can further extend the life of water-soluble coolant, thereby reducing the amount of
coolant and wastewater requiring treatment and disposal, and minimizing fresh coolant
requirements.
8.2.4
Centrifugation and Recycling of Painting Water Curtains
              Water curtains are a continuous flow of water behind the work piece being spray
painted in a paint booth.  The water traps paint overspray and is continuously recirculated in the
paint curtain until the solids content in the wastewater necessitates either in-process treatment
and recycling or discharge. Based on data from the 1996 MP&M detailed survey, approximately
12 MP&M facilities centrifuge and recycle water from their paint curtains.
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              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 facilities.
Moreover, if a facility uses only painting water curtains and continuously recycles the water, the
facility would not need end-of-pipe wastewater treatment.

              Figure 8-3 shows a diagram of a typical in-process centrifugation and recycling
treatment system for a paint curtain.  Centrifugal separators remove the solids and recycle the
water curtain, eliminating the need for discharge. This system can recycle, the paint curtain
water continuously.  The system pumps the water curtain from the paint curtain sump to a
holding tank, then through the centrifugal  separator, which separates the solids from the
wastewater (see section 8.2.3).  Solids from the centrifuge are hauled for off-site disposal, while
the treated wastewater is returned to the paint booth. Centrifugation of the paint curtain proceeds
until all wastewater is treated and only sludge remains in the paint curtain sump. Operators must
remove the sludge in the paint curtain sump either manually, with a sludge pump, or by vacuum
truck. The facility may add detactifiers before centrifugation to increase the solid separation
efficiency.  Detactifiers make the paint solids less sticky, allowing them to be more easily
removed from the centrifuge. Make-up water is added to the system to compensate for
evaporation.
         Chemical Addition
          (if necessary)
                                         Recycled Water
           Paint Solids
         to Contract Haul
           Figure 8-3. Centrifugation and Recycling of Painting Water Curtains


              As discussed in Section 8.2.3, centrifugal separators are very reliable and require
only routine maintenance. Flow rate is the primary operating factor to control.  One disadvantage
of this technology is that it may not be economically feasible for facilities generating only a small
amount of paint curtain wastewater.  Facilities that have multiple sumps can use portable
centrifuges.
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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

              The sludge generated from painting water curtains is commonly classified as a
hazardous waste, based on the type of paint used, and typically is hauled off-site for treatment
and disposal. See Appendix D for more information on pollution prevention practices with
painting operations.

8.2.5         Electrodialysis

              Electrodialysis is a process in which dissolved colloidal species are exchanged
between two liquids through selective semipermeable membranes (11).  The technology applies a
direct current across a series of alternating anion and cation exchange membranes to remove
dissolved metal salts and other ionic constituents from solutions.

              An electrodialysis unit consists of a rectifier and a membrane stack.  The rectifier
converts alternating current to direct current. The stack consists of alternating anion- and cation-
specific membranes that form compartments.  As the feed stream enters the unit, ions move
across the electrodialysis membranes, forming a concentrated stream and a deionized stream.
When the compartments are filled, a direct current is applied across each membrane in the stack.
Cations traverse one cation-specific membrane in the direction of the cathode and are trapped in
that concentrate compartment by the next membrane, which is anion-specific. Anions  from the
neighboring compartment traverse the anion-specific membrane in the direction of the  anode,
joining the cations, and are likewise trapped in the concentrate compartment by the next cation-
specific membrane. In this way, the technology depletes  the feed stream of ions, and traps anions
and cations in each concentrate compartment.  Facilities typically use electrodialysis to remove
metal ions from electroplating wastewater. Figure 8-4 shows a  diagram  of an electrodialysis cell.
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                                                 8.0 - Pollution Prevention and Wastewater Treatment Technologies
                  EDR Module
                         Cathode
                    Cathode Transfer
                        Membrane
                      Anion Transfer
                        Membrane
                    Cathode Transfer
                       Membrane
                              Figure 8-4.  Electrodialysis Cell
              By using the electrodialysis cell, facilities remove impurities from the process
bath, extending its life. Facilities can treat the removed concentrate stream on-site, or haul it off-
site for disposal, treatment, or metals reclamation.
8.2.6
Electrolytic Recovery
              Electrolytic recovery is an electrochemical process used to recover metal
contaminants from many types of process solutions and rinses, 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. Equipment
consists of one or more 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.

              Facilities typically apply electrolytic recovery to solutions containing either
nickel, copper, precious metals, or cadmium. Chromium cannot be electrolytically recovered
because it exists primarily in anionic forms such as dichromate.  Drag-out rinses and ion-
exchange regenerant are solutions that commonly 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
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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

recovered without pH adjustment. In some cases, when the target metal concentration is reached,
the waste stream can act as cation regenerant.

              The capacity of electrolytic recovery equipment depends on the total cathode area
and the maximum rated output of the rectifier.  Units are available with a cathode area ranging
from 1 ft2 to 100 ft2 or larger, and an output of  10 to 1,000 amperes or more. Faraday's law,
which  states the amount of chemical change produced by an electric current is proportional to the
quantity of electricity used, determines theoretical electrolytic recovery rates.  Theoretical
recovery rates range from  1.09 grams/amp-hour for nickel 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 concentrations under 100 mg/L, electrolytic recovery rates may be below 10
percent of the theoretical maximum.

              Electrolytic recovery units use various types of cations,  depending mainly on the
concentration of metal in the waste stream. Cathodes are often classified by their surface area.
Flat-plate cathodes have the lowest surface area and are used only for recovering metal from
metal-rich waste streams (usually 1,000 to 20,000 mg/L of metal). Reticulate cathodes, which
have a metallized woven fiber design, have a surface area 10 times greater than their apparent
area. These cathodes are effective over a wide  range of metal concentrations but typically are
used where the dissolved metal concentration is below 100 mg/L. Carbon and graphite cathodes
have the highest surface area per unit of apparent area. Their use is usually restricted to metal
concentrations below 1,000 mg/L.

              Reticulate or carbon cathodes can  recover metals  in electrolytes to concentrations
as low as 5 mg/L. Electrolytes are substances that dissociate into ions in solution (i.e., water),
thereby becoming electrically conducting (4). In  practice, however, the target effluent
concentration for most applications is 50 to 250 mg/L or higher because of the time and energy
required to achieve  concentrations less than 100 mg/L. With flat-plate cathodes, the target
effluent concentration is usually above 500 mg/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 units have relatively low labor requirements.  Units
recovering dissolved metal from  drag-out rinse tanks only may require occasional cleaning and
maintenance. Units treating batch discharges from ion-exchange units (see Section 8.2.8.1)
require more  labor due to the higher metal content of the solution and the resultant increase in
cathode loading frequency. Energy costs for this  technology can be high, 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.  In addition, from an
energy standpoint, electrolytic recovery removes metals from concentrated solutions more
efficiently than from dilute solutions.  Electrode replacement costs may be significant for units
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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

using disposable cathodes, especially for high metal recovery rates. However, if electrodes are
constructed properly, cathodes and anodes may last more than five years for most applications.

              Numerous vendors offer electrolytic recovery technology.  The technology is
applicable to a wide range of processes, drag-out rinses, and ion-exchange regenerants due to the
diversity of materials and configurations available for anodes and cathodes.  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, this technology cannot cost-effectively remove
dissolved metals to concentrations required for discharge to POTWs or surface waters.

8.2.7         Evaporation

              Evaporation is a volume reduction and water recovery technology applicable
when raw water costs are high or discharge to either a receiving stream or the local sewerage
district is not permitted. EPA estimates there are 147 MP&M facilities using evaporation to
reduce the volume of their waste and to recover and reuse their water.  Evaporators have the
potential to recover 95 percent of the water in a waste stream  for reuse in the process. MP&M
facilities use two basic types of evaporators:  atmospheric and vacuum. Atmospheric evaporators
are more prevalent and are relatively inexpensive to purchase and easy to operate. Vacuum
evaporators  are mechanically more sophisticated and are more energy-efficient.  Facilities
typically use vacuum evaporators when evaporation rates greater than 50 to  70 gallons per hour
are required. MP&M facilities use evaporators to recover metals from ion exchange regenerates,
to reduce the volume of oily wastes that require off-site transfer, and to recover and reuse rinse
water from plating operations.

              Equipment required for evaporation systems include (12):

              •     Basket strainers in lift  stations and sumps to prevent items like shop rags
                    from reaching the evaporator;

              •     Equalization tanks to handle batch dumps of process water;

              •     An oil skimmer in the  equalization tank to remove floatable oil;

              •     Evaporators (either vacuum or atmospheric);

              •     Residue holding tanks;

              •     Air pollution control equipment;

              •     A condenser to capture water vapor for return to the manufacturing
                    process; and

              •     Natural gas or propane tanks for evaporator fuel storage.
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Residue from evaporators can be recycled if sufficiently pure, disposed of off-site, or used for
energy recovery if the material has a sufficient BTU content.

8.2.8          Filtration

              Filtration removes suspended solids from surface finishing operations.  EPA
estimates there are nearly 150 MP&M facilities that use filters on their machining and grinding
operations to remove solids, debris, or swarf from machining coolants. If solids are not removed
from machining coolants, they may cause a rough or burred surface on the work piece. Filtered
coolants return to the manufacturing  process. In-process filtration extends  the life of the coolant
and reduces the amount of oil and grease sent to treatment. Filtration equipment includes
cartridge filters, precoat diatomaceous earth filters, sand, and 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.
The filter media used depends on the chemical and physical characteristics  of the bath, which
determine the filter material type, density, nominal micron retention, wet strength, mullen burst,
and air permeability. Material type is important to ensure the media is compatible with the liquid
being filtered.  Media density is how close or dense the media fibers are laid, laminated, or
woven. Nominal micron retention indicates the smallest particle size the media will retain to
develop a filter cake. Flux rate through the filter is determined by the air permeability
characteristics. All filtration systems are sized based on solids loading and  the required flow
rate.

              Membrane filtration also can remove oils and metals from process baths or rinses,
and remove solids from paint curtains or tramp oils from machine coolants  to extend usable life.
They are also commonly used to recover and recycle electrophoretic painting ("e-coat")
solutions. Membrane filtration is a pressure-driven process that separates solution components
based on molecular size and shape.  Solvent and small solutes can pass through the membrane
while the membrane retains and collects larger compounds as a concentrated waste stream.  The
cleaner permeate can be reused in the process while the concentrated waste stream is discharged
to treatment. Figure 8-5 shows a typical membrane filtration unit.
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                                                 8.0 - Pollution Prevention and Wastewater Treatment Technologies
             Concentrate
             Output
Influent- - -
Wastewater
                                                                        Tubular
                                                                        Membranes
                           Figure 8-5. Membrane Filtration Unit
8.2.8.1
Ion Exchange (in-process)
              Ion exchange is a commonly used technology within MP&M facilities. In
addition to water recycling and chemical recovery applications, ion exchange is used to soften or
deionize raw water for process solutions.  Figure 8-6 shows a typical ion-exchange system.

              Ion exchange is a reversible chemical reaction that 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 FT for other cations, while
anion resins exchange OH" for other anions (10).
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  Influent
                                                 8.0 - Pollution Prevention and Wastewater Treatment Technologies
Fresh Alkaline
 Regenerant
                  Metal-Bearing
                  Regenerant
             Non-Metal
              Bearing
             Regenerant
                                                                                 Effluent
                                 Figure 8-6.  Ion Exchange
              A feed stream passes through 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 organic pollutants that foul the resin
bed. The exchange process continues until the capacity of the resin is reached (i.e., an exchange
has occurred at all the resin sites).  A regenerant solution then passes through the column.  For
cation resins, the regenerant is an acid, and the FT 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 metals concentration is much higher in the regenerant than in the feed
stream; therefore, the ion-exchange process not only separates the metals from the waste stream
but also results in a more concentrated waste stream.

              MP&M facilities use ion exchange for water recycling and 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, the system can achieve closed-loop rinsing. The
regenerant from the cation column contains metal ions, which are recoverable in elemental form
via electrolytic recovery (see Section 8.2.6). The anion regenerant typically flows to wastewater
treatment.  Facilities use this type of ion exchange to recycle relatively dilute rinse streams.
Generally,  the TDS concentration of such streams must be below 500 mg/L to maintain an
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efficient regeneration frequency. Reducing drag-out can enhance the efficiency of the recovery
process. Effluent TDS concentrations of 2 mg/L or less are typical.

              When facilities are seeking only metal recovery, they use a single or double cation
column unit containing selective resin. These resins attract divalent cations while allowing
monovalent cations to pass, a process usually called metal scavenging. This technology is
efficient if the metal ions being scavenged are the primary source of ions in the stream. Ion
exchange provides effective metals recovery even when the metal content of the  stream is only a
small fraction of the TDS present in the stream, making scavenging suitable over a wider range
of TDS than water recycling. Scavenging also provides a highly concentrated regenerant,
particularly suitable for electrolytic recovery (see Section 8.2.6). Water recycling using this ion
exchange configuration is not possible because only some of the cations and none of the anions
are removed. Standard units typically achieve effluent metal concentrations of under 0.5 mg/L.

              Many process wastewaters are excellent candidates for ion exchange, including
the rinse water from plating processes of chromium, copper, cadmium, gold, lead, nickel, tin, tin-
lead, and zinc. Ion exchange resins usually are regenerated using inexpensive chemicals such as
sulfuric acid and sodium hydroxide. Gold-bearing resins are difficult to regenerate and
frequently require incineration to recover the gold content.  Lead also is difficult to recover from
ion exchange resins. Methane sulfonic acid and fluoboric acid (usually not suitable for
electrolytic recovery) are effective regenerants for lead ion exchange but are very expensive.
Cyanide rinse waters are amenable to ion exchange; cation resins can break the metal-cyanide
complex and the cyanide is removed in the anion column.  The metals in the cation regenerant
can be recovered electrolytically and the cyanide present in the anion regenerant  can be returned
to the process or discharged to treatment.

              Ion-exchange equipment ranges from small, manual,  single-column units to multi-
column, highly automated units.  Two sets of columns are necessary for continuous treatment;
one set receives the wastewater flow while the other set is being 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 involvement.

              The labor requirements for ion exchange depend  on the automation level of the
equipment. Manual systems can have significant labor costs associated with preparing,
transporting,  and disposing of regenerants. Automatic systems require far less labor.  Resins
need to be replaced periodically due to organic contamination, resin oxidation, and fouling from
suspended solids.  This process can be hastened by misuse, accidents, or poor engineering.

              Equipment size is based on flow rate 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
typically are sized to handle wastewater flow for at least a period of time equal to that required
for regeneration. Automatic systems are sized to provide continuous treatment.  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.
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8.2.8.2        Reverse Osmosis

              Reverse osmosis is a membrane separation technology used by MP&M facilities
for chemical recovery and water recycling.  The system pumps dilute rinse water to the surface of
the reverse osmosis membrane at pressures of 400 to 1,000 pounds per square inch gauge (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 retained by the membrane while the
permeate passes through.  Reverse osmosis membranes reject more than 99 percent of
multivalent ions and 90 to 96 percent of monovalent ions, in addition to organic pollutants and
nonionic dissolved solids. The permeate stream usually is 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. Reverse osmosis equipment is similar to the
equipment shown in Figure  8-5.

              A sufficiently concentrated reject stream can be returned directly to the process
bath.  Recycling the stream through the unit more than once or by increasing the feed pressure
can increase the reject stream concentration. 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 may, in some cases, have high enough
concentrations to go directly back to the bath.

              The capacity of reverse osmosis equipment generally is measured in flow volume,
and is determined by the membrane surface area and operating pressure.  Increasing the surface
area of the membrane usually increases the membrane capacity. Operating at higher pressures
increases the permeate flow volume per unit membrane area (also called the flux).  Reject stream
concentration increases with pressure and decreases as flow volume increases.

              Facilities may need to prefilter and pretreat the feed stream to lengthen membrane
life or reduce the frequency  of fouling; filtration to remove suspended solids is usually necessary.
Adjusting pH may prevent precipitation 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
electroplating of Watts nickel, bright nickel, brass cyanide, copper cyanide, and zinc cyanide.
This technology can treat TDS concentrations of up to 1,000 mg/L. Permeate TDS
concentrations of 250 mg/L  or less are typical, and the dissolved solids are mostly  commonly
monovalent ions, allowing the permeate stream to be reused in many rinsing operations.

              The maximum achievable reject stream concentration for basic reverse osmosis
equipment is approximately 20,000  mg/L TDS.  Multipass and multistage units achieve
concentrations of 30,000 mg/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 uncommon because the concentration
is often too low.  When the reject stream concentration is not high enough to return it to the bath,
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it can be concentrated with an evaporator, electrolytically recovered, or discharged to wastewater
treatment. When evaporators are used, however, reverse osmosis loses its low-energy advantage
over other in-process reuse and recovery technologies.

             Reverse osmosis often has a higher capital cost than does ion exchange when both
technologies include an electrolytic recovery unit. When used for water recycling, reverse
osmosis and ion exchange both remove similar quantities of metals; however, reverse osmosis
may allow for more water recycling.. During reverse osmosis, only the pumps use energy. In
most cases, water is recycled; in  some cases, a closed loop is possible.  Compared to ion
exchange, reverse osmosis can treat 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
organic compounds and total suspended  solids. Ion-exchange effluent generally has a lower IDS
concentration than does reverse osmosis permeate and can be recycled in most rinses.

             For most applications, reverse osmosis membranes last for one to five years,
although they are susceptible to fouling from organic pollutants, suspended solids, or misuse.
Reverse osmosis units may be able to track the condition of the membrane by measuring the flux.
If the membrane fouls or clogs, the flux rate drops, indicating that the membrane should be
cleaned. Labor associated with operating reverse osmosis equipment is for periodic membrane
cleaning. Membrane and pump replacement are the primary maintenance items.

8.3          Best Management Practices and Environmental Management Systems for
             Pollution Prevention

             EPA encourages the wide spread use of Best Management Practices (BMPs), and
Environmental Management Systems (EMS), to achieve improved environmental performance
and compliance, pollution prevention through source reduction, and continual improvement (see
EPA Position Statement on Environmental Management Systems, May 15, 2002, DCN  17848,
Section 24.4). However, as described in the Section IV of the preamble to the final rule, EPA is
not requiring the use of BMPs or EMSs for compliance with the MP&M effluent guidelines.

             Best Management Practices (BMPs)  are inherently pollution prevention practices.
BMPs may include the universe of pollution prevention encompassing production modifications,
operational changes, material substitution, materials and water conservation, and other such
measures (17). BMPs include methods to prevent the discharge of toxic and hazardous
pollutants. BMPs are most effective when organized into a comprehensive facility EMS.

             MP&M facilities  employ many types of pollution prevention measures including
the following: training and supervision; production planning; process or equipment modification;
raw material and product substitution or elimination; loss prevention and housekeeping; waste
segregation and separation; and closed-loop recycling. These practices are discussed in further
detail below (1).
                                          8-25

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                           8.0 - Pollution Prevention and Wastewater Treatment Technologies

Training and Supervision
Training and supervision ensure that employees are aware of, understand,
and support the company's pollution prevention goals.  Effective training
programs translate these goals into practical information that enables
employees to minimize waste generation by properly and efficiently using
tools, supplies, equipment, and materials.

Production Planning
Production planning can minimize the number of process operation steps
and eliminate unnecessary procedures (e.g., production planning can
eliminate additional cleaning steps between process operations).

Process or Equipment Modification
Facilities can modify processes and equipment to minimize the amount of
waste generated (e.g., changing rack configuration to reduce drag-out).

Raw Material and  Product Substitution or Elimination
Where possible, facilities should replace toxic or hazardous raw materials
or products with other materials that produce less waste and less toxic
waste (e.g., replacing chromium-bearing solutions with non-chromium-
bearing and less toxic solutions, or consolidating types of cleaning
solutions and machining coolants).

Loss Prevention and Housekeeping
Loss prevention and housekeeping includes performing preventive
maintenance and managing equipment and materials to minimize leaks,
spills, evaporative losses, and other releases (e.g., 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).

Waste Segregation and Separation
Facilities should avoid mixing different types of wastes or mixing
hazardous wastes with nonhazardous wastes. Similarly, facilities should
not mix recyclable materials with noncompatible materials or wastes. For
example, facilities can segregate scrap metal by metal type, separate
cyanide-bearing wastewater for preliminary treatment, and segregate
coolants  for recycling or treatment.

Closed-Loop Recycling
Facilities can recover and reuse some process streams.  For example, some
facilities can use ion exchange to recover metal from electroplating rinse
water, reuse the rinse water, and reuse the regenerant solution as process
solution make-up.
                      8-26

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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

              The following sections describe pollution prevention opportunities for a few
MP&M facilities.

8.3.1          Pollution Prevention for Cleaning and Degreasing Operations

              The majority of facilities in the Oily Wastes Subcategory perform cleaning and
degreasing operations to remove residual oil and coolants from metal parts following machining
and grinding operations. These facilities also perform cleaning and degreasing on equipment
undergoing maintenance. Opportunities to reduce waste from these operations include process
elimination, material substitution, in-process recycling, waste segregation, maintenance/
housekeeping, procedures/scheduling, and equipment layout/piping/automation. Examples of
these opportunities are presented below (15).

              Process Elimination

              •       Determine whether parts need to be cleaned;

              •       Use easy-to-clean or no-clean rust inhibitors and lubricants;

              •       Review the parts-handling process to determine why parts are getting dirty,
                     and take action to prevent it from happening in the future; and

              •       Purchase clean input stock.

              Material Substitution

              •       Clean by brushing and wiping where possible;
              •       Use aqueous-based cleaners;
              •       Use solvents with low vapor pressure and high flash point; and
              •       Use citrus or terpene cleaners.

              In-Process Recycling

              •       Use countercurrent rinsing;

              •       Skim/filter and reuse aqueous cleaners;

              •       Reuse solvents by installing filtration or distillation units; and

              •       Install a bioremediation parts washer that uses enzymes to remove oil and
                     grease.
                                           8-27

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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

              Waste Segregation

              •       Segregate solvents to allow recycling;

              •       Keep solvents out of waste oil;

              •       Keep fuel, brake fluid and other fluids out of solvents to prevent the
                     mixture from becoming hazardous; and

              •       Keep solvents out of aqueous cleaners.

              Maintenance/Housekeeping

              •       Use secondary containment for solvent storage; and
              •       Implement a maintenance program to fix and prevent leaks.

              Procedures/Scheduling

              •       Reduce dragout by increasing drain time; and
              •       When dripping parts, lift them such that it reduces dragout.

              Equipment Layout/Piping/Automation

              •       Install sliding lids on solvent tanks;
              •       Increase the freeboard height to significantly reduce solvent evaporation;
              •       Install automatic parts lift on vapor degreasers;
              •       Use drain racks to reduce dragout; and
              •       Drain parts using a rotating rack.

8.3.2          Pollution Prevention for Machining Operations

              Many machining operations use metal-working fluids to cool and lubricate parts
and machining tools during cutting, drilling, milling, and other machining operations. These
fluids become contaminated and begin to lose their working characteristics. If neglected, the
fluids become unusable and require treatment and disposal. Through proper care, the life span of
the fluids can be extended indefinitely. For most machining operations, prolonging metal-
working fluid life reduces the cost of treatment and disposal, as well as the cost of fresh coolant.

              Many MP&M facilities use  some type of pollution prevention and water
conservation practices for machining wastewaters.  Some facilities have implemented numerous
pollution prevention and water conservation methods and technologies that result in very low
machining wastewater discharge  rates and in some cases eliminate the discharge of machining
fluids. Pollution prevention and water conservation practices are applicable to all machining
                                           8-28

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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

operations; however, process-related factors and site-specific conditions may restrict the utility of
certain methods.

              The Agency has identified two categories of pollution prevention and water
conservation practices and technologies that can be used to reduce metal-working fluid
discharge: those used to prevent metal-working fluid contamination and those used to extend the
life of machining fluids, including recovering and recycling metal-working fluids. Within each
of these categories are several specific practices and technologies. See Appendix D for more
information on these pollution prevention practices.

8.3.3          Painting Operations

              Paint is applied to a base material for protective and decorative reasons in various
forms, including dry powder, solvent-diluted formulations, and water-borne formulations. There
are various methods of application, the most common being immersion and spraying.  Water is
used in painting operations in paint booth water-wash systems (water curtains),  in water-borne
formulations, in electrophoretic painting solutions and rinses, and in clean-up operations.  This
discussion is directed at water use in spray painting booths; however, Appendix D also provides
some information on rinsing following electrophoretic painting and water clean-up.
              EPA has identified three categories of pollution prevention and water
conservation practices that, if implemented, can reduce or eliminate wastewater discharges from
painting operations:  practices to reduce the quantity of paint entering the water system; recycling
technologies for paint booth water; and conversion of water-wash booths to dry-filter booths.
These are discussed in this subsection and summarized in Appendix D. It is possible, however,
that facilities can reduce or eliminate wastewater discharges using different practices than those
described here.

8.3.4          Pollution Prevention for Printed Wiring Board Manufacturing

              Printed wiring board manufacturers use a large amount of water each day, mostly
for rinsing and electroplating processes.  The following BMP's developed specifically for printed
wiring board manufacturing outline water-saving process changes and controls that can be
inexpensively  incorporated in the production process.  A number of these pollution prevention
processes are described in more detail in Section 8.1.

              •     Use dry film photoresist instead of wet applications.

              •     Examine the pre-plating rinse processes:

                           Based on monitoring data, eliminate unnecessary  cycles  and rinse
                           only until desired cleanliness is reached.

                            Switch from continuous to on-demand rinsing, and from once-
                           through  to closed-loop use.
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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

                            Use counter-current rinsing.

                            Use air or workpiece agitation to increase rinsing efficiency.

                            Spray rinse with high-pressure, low flow nozzles.  This can reduce
                            rinse water use up to 60 percent.

                            Link flow controls to conductivity meters that measure the total
                            dissolved solids in the rinses.

              •      Examine the electroplating process.  Extending bath life will reduce both
                     water consumption and toxics in the effluent.

                            Reduce drag-in through efficient rinsing.

                            Use deionized or distilled water for makeup.

                            Reduce drag-out through the following methods:

                            a)    Minimize bath chemical concentrations.

                            b)    Use nonionic wetting agents to reduce surface tension in
                                  the process baths.

                            c)    Prior to rinsing, maximize water returned to the process
                                  bath through several measures - withdraw pieces from the
                                  baths slowly, install drainage boards between process baths
                                  and rinses to return drag-out back to the process bath,
                                  install rails above process baths to hang workpiece/racks
                                  for drainage and/or use air knives or spray rinses above
                                  process baths to rinse excess solution into the process bath.

                            Restore barrel holes.

                            Maintain bath solution  quality through monitoring, replacement of
                            reagents and stabilizers, and impurity removal.

              •      Install multiple baths after the process bath for using counter-current
                     rinsing wherever possible.

8.4           Preliminary Treatment of Segregated Wastewater Streams

              Preliminary treatment systems reduce pollutant loadings in segregated waste
streams prior to combined end-of-pipe treatment. Wastewater containing pollutants such as
                                           8-30

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                                               8.0 - Pollution Prevention and Wastewater Treatment Technologies

cyanide, hexavalent chromium, oil and grease, or chelated metals may not be treated effectively
by chemical precipitation and gravity settling without preliminary treatment. Proper segregation
and treatment of these streams is critical for the successful treatment of process wastewater.
Highly concentrated metal-bearing wastewater also may require pretreatment to reduce metal
concentrations before end-of-pipe treatment.  This subsection describes the following wastewater
streams that typically undergo preliminary treatment at MP&M facilities:

                     •      Chromium-bearing wastewater;
                     •      Concentrated metal-bearing wastewater;
                     •      Cyanide-bearing wastewater;
                     •      Chelated metal-bearing wastewater; and
                     •      Oil-bearing wastewater.

Table 8-3 summarizes these preliminary treatment operations.

8.4.1          Chromium-Bearing Wastewater

              MP&M facilities generate hexavalent-chromium-bearing wastewater from acid
treatment, anodizing, conversion coating, and electroplating operations and rinses.  Hexavalent
chromium exists in an ionic form and does not form a metal hydroxide; therefore, hexavalent
chromium cannot be treated by chemical  precipitation and sedimentation (discussed in Section
8.5.1). The wastewater requires preliminary chemical treatment to reduce the hexavalent
chromium to trivalent chromium, which can be removed by chemical precipitation and
sedimentation. As shown in Table 8-3, EPA estimates there are over 1,800 MP&M facilities that
perform hexavalent chromium reduction. The chemical reduction process is discussed below.
Figure 8-7 presents a diagram of a continuous chromium reduction system.
                                          8-31

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                                                                                  8.0 - Pollution Prevention and Wastewater Treatment Technologies
                                                          Table 8-3
                              MP&M Preliminary and End-of-Pipe Treatment Technologies
Technology
Chemical Emulsion Breaking
Followed by Gravity Oil/Water
Separation
Chemical Emulsion Breaking
Followed by Dissolved Air
Flotation
Chemical Reduction of
Hexavalent Chromium
Cyanide Destruction by
Alkaline Chlorination
Oil Skimming of Oily
Wastewater Streams
Cyanide Oxidation by Ozone
Chelation Breaking/
Precipitation to Remove
Complexed Metals
Ultrafiltration
Activated Carbon Adsorption
Aerobic Biological Treatment
Air Stripping
Technology Description
Adds acids (typically sulfuric), polymer, and sometimes alum to oil-
bearing wastewater to break oil/water emulsions for subsequent gravity
separation. Separated oil is skimmed and hauled by a contractor. A
facility may purchase the recycled oil for reuse.
Adds acids (typically sulfuric), polymer, and sometimes alum to oil-
bearing wastewater to break oil/water emulsions for subsequent gravity
separation. Introduces gas bubbles into the wastewater, bringing oils and
solids to the surface for subsequent removal.
Reduces hexavalent chromium to trivalent chromium using a reducing
agent such as sulfur dioxide, sodium bisulfite, or sodium metabisulfite.
Destroys cyanide by adding chlorine (usually sodium hypochlorite or
chlorine gas) to high pH wastewater to first oxidize cyanide to cyanate,
then cyanate to carbon dioxide and nitrogen gas.
Removes free floating oil by gravity separation and mechanical
skimming. This technology does not remove emulsified oils.
Ozone oxidizes cyanide to ammonia, carbon dioxide and oxygen.
Wastewater from electroless plating and some cleaning operations
contains chelated metals that cannot be removed by chemical
precipitation. Strong reducing agents such as dithiocarbamate are added
to break the metal-organic chelate bond and precipitate the metal.
Removes emulsified or free-floating oils. This technology also removes
other solids. Uses a membrane of very small pore size.
Removes dissolved organic pollutants by filtration through and
adsorption on activated carbon. This technology requires preliminary
treatment to remove suspended solids and oil and grease.
Biochemically decomposes organic materials in the presence of oxygen
using microorganisms.
Removes dissolved volatile 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.
Demonstration Status
Number of
Facilities Visited
Using the
Technology a
13
85
56
14
45
0
15
19
9
1
(used to treat
nonprocess
wastewater)
0
Number of
Survey
Facilities Using
the Technology1"
56
25
103
53
89
1
49
23
21
4
2
Estimated Number
of MP&M Facilities
Using the
Technology0
958
244
1,839
1,136
2,087
4
555
351
165
130
14
oo
OJ
to

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                                                                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies
                                                            Table 8-3 (Continued)
Technology
Neutralization
Chemical Precipitation and
Gravity Sedimentation
Chemical Precipitation and
Micro filtration
Atmospheric Evaporation
Ion Exchange (end-of-pipe)
Multimedia Filtration
Sand Filtration
Gravity Settling
Centrifugation of Sludge
Gravity Thickening of Sludge
Technology Description
Neutralizes high or low pH wastewater to within an acceptable range
using acidic or alkaline chemicals. Common acids include sulfuric and
hydrochloric. Common alkaline chemicals include lime and sodium
hydroxide.
Removes metals by precipitating insoluble compounds such as
hydroxides, sulfides, or carbonates. Precipitation as metal hydroxides
using lime or sodium hydroxide is the most common. Precipitated and
flocculated solids are removed by gravity sedimentation in a clarifier.
Removes metals by precipitating insoluble compounds such as
hydroxides, sulfides, or carbonates. Precipitation as metal hydroxides
using lime or sodium hydroxide is the most common. Precipitated and
flocculated solids are removed by micro filtration through a porous
membrane.
Includes both natural solar evaporation and forced atmospheric
evaporation by which the evaporation rate is accelerated by increased
temperature, air flow, and surface area.
Polishing technique after metals precipitation to scavenge low
concentrations of residual metals (cations) using combined cation and
anion exchange. Anions remain in solution and are discharged.
Concentrated metal-containing regenerants are typically returned to the
metals precipitation system.
Removes solids from wastewater using filter media of different grain
size. Coarser media remove larger particles and finer media remove
smaller particles. Media include garnet, sand, and anthracite coal. The
filter is periodically backwashed to remove solids.
Removes solids from wastewater using a sand filter. The filter is
periodically backwashed to remove solids.
Physically removes suspended particles by gravity. This technology does
not include the addition of any chemicals.
Separates water from solids using centrifugal force. Centrifugation
dewaters sludges, reducing the volume and creating a semisolid cake.
Centrifugation of sludge can typically achieve a sludge of 20-35 percent
solids.
Physically separates solids and water by gravity. Gravity thickening can
typically thicken sludge to 5 percent solids.
Demonstration Status
Number of
Facilities Visited
Using the
Technology a
63
149
6
4
17
12
46
7
7
83
Number of
Survey
Facilities Using
the Technology1"
233
203
5
12
39
16
41
46
9
85
Estimated Number
of MP&M Facilities
Using the
Technology0
3,713
2,981
36
142
251
354
830
1,679
127
1,161
oo

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                                                                                                                  8.0 - Pollution Prevention and Wastewater Treatment Technologies
                                                                        Table 8-3 (Continued)
Technology
Pressure Filtration of Sludge
Sludge Drying
Vacuum Filtration of Sludge
Technology Description
Physically separates solids and water by pressure filtration. 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 percent
solids.
Dries sludge by heating, which causes the water in the sludge to
evaporate.
Physically separates solids and water by vacuum filtration. Most
commonly performed in a cylindrical drum vacuum filter, where water is
pulled by vacuum through the filter and dewatered sludge is retained and
subsequently scraped from the filter surface. Vacuum filtration can
nroduce a sludae cake with 20 - 30 nercent solids.
Demonstration Status
Number of
Facilities Visited
Using the
Technology a
140
28
11
Number of
Survey
Facilities Using
the Technology1"
189
48
9
Estimated Number
of MP&M Facilities
Using the
Technology0
3,106
835
193
oo
        Source:  MP&M site visits, MP&M sampling episodes, MP&M surveys and technical literature. Statistics specific to wastewater-discharging facilities.
        ^Indicates the number of MP&M facilities visited by EPA using the listed technology. EPA visited a total of 221 facilities.
        Indicates the number of water-discharging survey facilities that reported using this technology. Based on 874 MP&M survey respondents for the 1996 detailed survey and the
        1989 survey.
        'Indicates the estimated number of MP&M facilities currently performing this technology based on the 1989 and 1996 detailed surveys. EPA's national estimate of the 1996
        detailed survey and the 1989 survey includes approximately 44,000 water-discharging facilities. EPA estimated numbers in this column using statistical weighting factors for the
        MP&M survey respondents. See Section 3.0 for a discussion of the development of national estimates and statistical survey weights.

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                                                  8.0 - Pollution Prevention and Wastewater Treatment Technologies
                Inlet (Influent)
       Hexavalent
  Chromium—Bearing
    Wastewater from
    Unit Operations
                                  Reducing Agent
                             (Sulfer Dioxide, Sodium Bisulfite,
                           Sodium Metabisulfite or Ferrous Sulfate)
                              Sulfur ic
                               Acid
                 Motor •
                                                    Mixer
                                  Reaction
                                   Tank

                             ORP=250-300 millivolts
                                   pH=2
                                                    • Oxidation—Reduction
                                                     Potential (ORP) Meter
Trivalent Chromium—
Bearing Wastewater
                                                   | Outlet (Effluent)
              -To Chemical Precipitation
               and Sedimentation
                  Figure 8-7.  Chemical Reduction of Hexavalent Chrome


              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, peroxide, and ferrous sulfate form strong reducing agents in water.
MP&M facilities use these agents to reduce hexavalent chromium to the trivalent form, which
allows the metal to be removed from solution by subsequent chemical precipitation.

              Sodium metabisulfite, sodium bisulfite, and sulfur dioxide are the most widely
used reducing agents at MP&M facilities (14). Below is an equation showing the sulfur dioxide
reaction (reduction using other reagents is similar chemically):
                          2H2Cr04 +  3S02 - Cr2(SO4)3  + 2H2O
                         (8-2)
              An operating pH of between 2 and 3 is normal for chromium reduction.  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.

              Typically, the chemicals are retained in a reaction tank for 45 minutes.  The tank
is equipped with pH and oxidation-reduction potential (ORP) controls.  Sulfuric acid is added to
maintain a pH of approximately 2, and a reducing agent is metered to the reaction tank to
maintain the target ORP.

              Chemical reduction of hexavalent chromium is a proven technology that is widely
used at MP&M facilities. Operation at ambient conditions requires little energy, and the process
                                             8-35

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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

is well suited to automatic control.  For high concentrations of chromium, treatment chemical
costs may be significant.

              Maintenance of chemical reduction systems consists of sludge removal, the
frequency of which depends on the concentration of contaminants. There also may be small
amounts of sludge generated due to minor shifts in the solubility of the contaminants (e.g., iron
hydroxides).  This sludge can be removed by the sludge-handling equipment associated with
subsequent end-of-pipe chemical precipitation and sedimentation.

8.4.2         Concentrated Metal-Bearing Wastewater

              Facilities use several methods to manage concentrated metal-bearing wastewater
from spent process solutions.  Facilities may:

              •       Meter the concentrated metal-bearing wastewater slowly to the end-of-pipe
                     chemical precipitation system and commingle it with other facility
                     wastewater;

              •       Treat the concentrated metal-bearing wastewater in a batch pretreatment
                     system; or

              •       Send concentrated metal-bearing wastewater for off-site treatment.

              Batch pretreatment allows better control of the treatment system (e.g., the
treatment chemicals can be better tailored to the specific solution being treated), better treatment
of difficult-to-treat materials (e.g., photo-resist-bearing wastewater), and potential recovery of
metals from the sludge. With batch treatment, facilities typically discharge effluent from the
batch treatment tank to the end-of-pipe treatment system for additional polishing.

              Batch chemical precipitation of concentrated metal-bearing wastewater typically
occurs in a single stirred tank, where a precipitating agent (e.g., sodium hydroxide,  lime, sodium
sulfide) is added to create an insoluble metal hydroxide or sulfide complex. Following
precipitate formation, a polyelectrolyte is added to flocculate the metal hydroxide or metal
sulfide particles into larger clumps that will settle to the bottom of the reaction tank following
mixing. Clarified effluent from the batch tank is discharged to the end-of-pipe treatment system
and the  settled sludge, typically containing only one type of metal, is transferred off-site for
metals recovery.

8.4.3         Cyanide-Bearing Wastewater

              Plating and cleaning wastewater may contain significant amounts of cyanide,
which should be removed through preliminary treatment. In addition to its toxicity, cyanide
forms complexes with metals that prohibit subsequent removal in chemical precipitation systems.
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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies
Cyanide typically is treated using alkaline chlorination with sodium hypochlorite or chlorine gas
or by ozone oxidation.  These two processes are described below.
8.4.3.1
              Alkaline Chlorination
              Alkaline chlorination is in wide use in industrial wastewater treatment to destroy
cyanide.  Table 8-3 shows there are over 1,100 MP&M facilities using alkaline chlorination to
remove cyanide. Chlorine is typically used as either chlorine gas or sodium hypochlorite (i.e.,
bleach).  The alkaline chlorination process oxidizes cyanides to carbon dioxide and nitrogen by
the following two-step  chemical reaction (10):
                   C12  + NaCN  +  2NaOH -  NaCNO +  2NaCl +

               C12  + 4NaOH  +  2NaCNO - 2CO2  + N2 +  6NaCl

Figure 8-8 presents  a diagram of an alkaline chlorination system.
                                                                                     (g-3)

                                                                                     (g-4)
                          Sodium
                         Hypochlorite
                                                                  Sodium
                                                                 Hypochlorite
Inlet (Influe
Cyanide-Bearing
Wastewalerfrom
Unit Operations
PH
Meter -
nt) Sodium
	 x. Hydroxide
airT~~
/P
p
j^>
,O.
Reaction
Tank
Cyanide converted to Cyanate
ORP=350-400 millivolts
PH
Potential (ORP) Meter
pH=1U-1 C 	 '—
I Outlet (Effluent) Cyanide-Bearing
Acid
d^^
React io
Tank
Cyanate convertec
and Dioxide to
ORP=660 mi
pH=8-9
s
I Tllb^
(9-
to Carbon
Nitrogen

Potential (ORP) Meter
i volts C. 	
I Treated Wastewater to
                                                                              ischarge or to Chemical
                                                                             Precipitation & Sedimentation
             Figure 8-8. Cyanide Destruction Through Alkaline Chlorination
              Treatment equipment often consists of an equalization tank followed by two
continuous reaction tanks, although the batch reaction can occur in a single tank. Each tank has
an electronic controller to monitor and maintain the required pH and ORP. To oxidize cyanides
to cyanates, chlorine or sodium hypochlorite is metered to the first reaction tank as necessary to
maintain the ORP at 350 to 400 millivolts, and aqueous sodium hydroxide is added to maintain a
pH of approximately 11.  This pH dictates that most of the cyanide exists in the CN" form, rather
than as the highly toxic hydrogen cyanide (HCN) form.  In the second reaction tank, the ORP and
the pH level typically 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 typically occurs in two tanks, one to collect water over a
specified time period and one to treat an accumulated batch. If concentrated wastes are
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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies

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 take place at ambient temperature, can be automatically
controlled at relatively low cost, and can achieve effluent concentrations of free cyanide that are
below the detection limit.  Disadvantages include the need for careful pH control, possible
chemical interference in treating mixed wastes, and the potential hazard of storing and handling
chlorine gas (if sodium hypochlorite is not used). If organic compounds are present, chlorinated
organic compounds may be generated.  Additionally, there are several safety  concerns associated
with handling chlorine gas and with the gas feed system.  This technology is not effective in
treating metallocyanide complexes, such as ferrocyanide.

8.4.3.2        Ozone Oxidation

              A less common cyanide treatment method is ozone oxidation. Ozone, generated
as a gas, is bubbled through a wastewater solution containing free cyanide. The ozone reacts
with cyanide, converting it to cyanate. Additional ozone reacts with the cyanate to convert it to
nitrogen gas,  ammonia, and bicarbonate, as shown by the reactions below.
                                     O3  ------- >CNO- + O2                           (8-5)

              3 CM)' + 2O3 + 2OH- + 2H2O ----------- > 3HCO3- + NH3 + N2 + 2O2          (8-6)

              The reaction rate is limited by mass transfer of ozone to the solution, the cyanide
concentration, and temperature. Literature data show that oxidation can reduce amenable
cyanide in electroplating wastewaters to below detection (5).  Ozone is not effective in treating
metallocyanide complexes, such as ferrocyanide, unless ultraviolet light is added to the reaction
tank (6).

              One advantage ozone has over chlorine is the type of residuals formed.  Chlorine
oxidation of organic compounds has the potential to form trihalomethanes. Ozone oxidizes
organic compounds to form relatively less toxic, short-chain organic acids, ketones, and
aldehydes. Equipment required for ozone oxidation of cyanides includes an ozone generator, gas
diffusion system, a mixed reaction tank, and off-gas controls to prevent the release of unreacted
ozone.

              The major disadvantage of the ozone oxidation process is the capital and
operating cost (12).  Ozone must be manufactured on-site and delivered directly to the  reaction
tank.  Ozone generation equipment is expensive, and facilities also must purchase closed reaction
tanks and ozone off-gas treatment equipment.
                                           8-38

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                                               8.0 - Pollution Prevention and Wastewater Treatment Technologies

8.4.4          Chelated-Metal-Bearing Wastewater

              Certain process wastewaters evaluated for the final rule contain chelating agents
that form metal complexes and interfere with conventional chemical precipitation treatment.
This wastewater is often associated with electroless plating and requires 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.

8.4.4.1        Reduction to Elemental Metal

              Reduction to elemental metal can be done using one of two methods.  One method
is electrolytic recovery (see Section 8.2.6), in which the dissolved metal is deposited on a 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 depend on
the volume of wastewater per unit surface area of cathode. This method typically does not lower
metal concentrations to levels sufficient for wastewater discharge.

              The second method uses a reducing agent to provide the electrons to reduce the
metal. Possible reducing agents for treating chelated wastewater streams include:

              •     Dithiocarbamate (DTC);
              •     Sodium borohydride;
              •     Hydrazine; and
              •     Sodium hydrosulfite.

Upon reduction, the metal forms a particulate in solution, which a solids removal technique, such
as gravity clarification,  can remove.  For effective use, these reducing agents sometimes require
the use of other chemicals (e.g., lime or sodium hydroxide) for pH adjustment. Figure 8-9
presents a diagram showing this method of chemical reduction of chelated metals.
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                              Reducing/Precipitation Agent,
                                Sodium Borohydride or
                                  Dithiocarbamate
                                                 8.0 - Pollution Prevention and Wastewater Treatment Technologies
                                                    Mixer
Lime or
Inlet (Influent) Sodium
Chelated Metal- N \ 	 •
Bearing Wastewater .*- — | [ If"
from Unit Operations
pH
Meter


Periodic
P .(. i e°i..-j. 	 -

Removal
"^--JJ T ' J_L
t &
Reaction
Tank



                                                                 Treated
                                                                 Metal-Bearing
                                                                 Wastewater
                                                    Outlet (Effluent)
                                                                             "To Chemical Precipitation
                                                                             and Sedimentation
8.4.4.2
             Figure 8-9.  Chemical Reduction / Precipitation of Chelated Metals
Precipitation as an Insoluble Compound
              Chelating agents hinder the formation of hydroxides, making hydroxide
precipitation ineffective for treating chelated-metal-bearing wastewaters.  Other precipitation
methods that are less affected by chelating agents include sulfide precipitation, DTC
precipitation, and carbonate precipitation.  Section 8.5.1 discusses sulfide precipitation and
carbonate precipitation.

              DTC is added to solution in stoichiometric ratio to the metals present. Equation
8-7 shows the reduction of nickel using DTC:
                                Ni2
                                    (aq)
                         + DTC2
                                  (aq)
(s)
                             (8-7)
DTC is effective in treating wastewater containing chelated metals.  Based on information
provided in the MP&M Detailed Surveys, approximately 53 percent of MP&M facilities with
chelated metals use DTC for treatment. DTC compounds are a class of pesticides and, if used
incorrectly, may cause process upsets in the biological treatment system used at the POTW and
can potentially be harmful to the environment (e.g., lead to fish kills if it passes through the
POTW and reaches surface  waters). Another disadvantage is that DTC precipitation generates
large amounts of sludge.
              Other treatment chemicals used by MP&M industries for treatment of chelated
metals include:
                     Borohydride;
                     Sodium hydrosulfite;
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              •       Sodium metabisulfite;
              •       Polysulfide polymer;
              •       Sodium hydroxide;
              •       Ferrous sulfate;
              •       Ferris chloride; and
              •       Formaldehyde.

              EPA evaluated the treatment performance of polysulfide polymer (Sampling
Episode 6462) and determined this compound effectively treated chelated copper and nickel to
metal finishing effluent limits (40 CFR 433).  Further concentration reductions may have been
achievable if additional jar testing was conducted. Iron or calcium salts  and pH adjustment may
also provide acceptable methods for chelated  metals treatment; however, no data are available for
evaluation.

              The Orange County Sanitation District (OCSD) compile a study of a NDMA and
found that the highest concentrations of a probable human carcinogen, n-nitrosodimethylamine
(NDMA), at a printed circuit board manufacturer were observed at effluent from batch treatment
(18). "Overdosing" of DTC in batch treatment systems may be common and may lead to the
formation of NDMA. During its evaluation OCSD encouraged facilities  and treatment chemical
vendors to develop non-NDMA forming treatments. EPA compiled information on DTC
alternative treatments for the record (see "DTC Alternatives for Treatment of Chelated Metals,"
Section 24.6.1  of the  rulemaking record, DCN 17962).

8.4.4.3        Physical Separation

              Ion exchange and reverse osmosis can separate metals from solution. These
technologies are not affected by chelating agents in the wastewater, making them effective in
treating wastewater from electroless plating.   Sections 8.2.8.1 and 8.2.8.2, respectively, discuss
these technologies.

8.4.5          Oil-Bearing Wastewater

              Some  MP&M wastewater (e.g., alkaline cleaning wastewater and water-based
metal-working fluids) contains significant amounts of oil and grease. This wastewater
sometimes requires preliminary treatment to remove oil and grease and organic pollutants.
Oil/water separation includes breaking oil/water emulsions (oil dispersed in water,  stabilized by
electrical charges and emulsifying agents) as well  as gravity separation of oil. When only free oil
(i.e., nonemulsified oil) is present, oil skimming is enough for effective treatment.  Techniques
available to remove oil include chemical  emulsion breaking followed by oil/water separation or
dissolved air flotation (DAF), oil skimming, and ultrafiltration. These technologies are described
in more detail below.

              Oil/water separation not only removes oil but also removes organic compounds
that are more soluble in oil than in water. Subsequent clarification removes organic solids
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directly and may also remove dissolved organic compounds by adsorption on inorganic solids.
MP&M operations, sources of these organic compounds mainly are process coolants and
lubricants, additives to formulations of cleaners, paint formulations, or leaching from plastic
lines and other materials.
                                                                         In
8.4.5.1
Chemical Emulsion Breaking
              Chemical emulsion breaking is used to break stable oil/water emulsions.  A stable
emulsion will not separate or break down without chemical and or physical treatment. Chemical
emulsion breaking is applicable to wastewater containing emulsified coolants and lubricants such
as machining and grinding coolants and impact and pressure deformation lubricants.  This
technology also is applicable to cleaning solutions that contain emulsified oils.  Figure 8-10
shows a diagram of a type of continuous chemical emulsion breaking system.
                                                                Chemical Addition
                                                                (Polymer. Alum. Ferric Chloride)
     Figure 8-10.  Continuous Chemical Emulsion Breaking Unit with Coalescing Plates


              Treatment of spent oil/water emulsions involves adding chemicals to break the
emulsion followed by oil/water 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 breaking 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)
break emulsions and allow coagulation (13) by neutralizing repulsive charges between particles,
precipitating or salting out emulsifying agents, or weakening the interfacial film between the oil
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and water so it is readily broken.  Reactive cations (e.g., H+, Al+3, Fe+3) and cationic polymers are
particularly effective in breaking dilute oil/water emulsions.  Once the charges are 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 adding the chemicals can affect both breaking efficiency and chemical
dosages.

              Another important consideration in emulsion breaking is pH, especially if cationic
inorganic chemicals, such as alum,  serve as coagulants. For example, a pH of between 2 and 4
keeps the aluminum ion in its most positive state where it most effectively neutralizes charges.
After some of the oil is broken free and skimmed, 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, this process usually requires
adding an inorganic flocculent to supplement the adsorptive properties of the polymer emulsion
breaker.

              Mixing is important in effectively breaking oil/water emulsions because it
provides  proper chemical feed and dispersion. Mixing also causes droplets to collide and break
the emulsion and promotes subsequent agglomeration into larger droplets. Heating also
improves chemical emulsion breaking by lowering the viscosity and increasing the apparent
specific gravity differential between oil  and water. In addition, heating increases the frequency
of droplet collisions, which helps to rupture the interfacial film.

              Once an emulsion is broken, the oil floats to the surface of the water because of
the difference in specific gravity between oil and water.  Solids usually form a layer between the
oil and water because 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 typically are
skimmed from the surface  of the water after chemical emulsion breaking. Often, other
techniques such as air flotation or rotational separation (e.g., centrifugation) 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,  operator training requirements for batch treatment,
chemical sludges produced, and poor efficiency for low oil concentrations.

              Chemical emulsion breaking is a very reliable process. The main control
parameters are pH and temperature. Some MP&M facilities may achieve effective emulsion
breaking by lowering the pH with acid, by heating the wastewater, or both.  Maintenance is
required  on pumps, mixers, instrumentation and valves, as is periodic cleaning of the treatment
tank to remove any accumulated solids. Energy use typically is limited to mixers and pumps,  but
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also can 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 contains a low enough percentage of water, it may be burned for its fuel value or
processed and reused.
8.4.5.2
Oil Skimming
              Oil skimming is a physical separation technology that removes free or floating oil
from wastewater using the difference in specific gravity between oil and water.  Common
separation devices include belts, rotating drums, disks, and weir oil skimmers and coalescers.
These devices are not suited to remove emulsified oil, which requires chemical treatment,
ultrafiltration, or other treatment.  Figures 8-1 la and 8-1 Ib show diagrams of disk and belt oil
skimming units, respectively, that are applicable for small systems or on process tanks. The oil
removal system shown in Figure 8-10 is a coalescing separator used for large systems.
                                                      Disk Movement
                                    Figure 8-1 la.  Disk
                                    Oil Skimming Unit
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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies
                                                    Belt
                                                    Movement
                                      Figure 8-1 Ib.
                                 Belt Oil Skimming Unit
              To separate oil from process solutions, oil skimming devices typically mount onto
the side of a tank and operate on a continuous basis.  The disk skimmer is a vertically rotating
disk that is partially submerged in the solution (see Figure 8-1 la). The disk continuously
revolves between spring-loaded wiper blades that are located above the liquid surface.  The
disk's adhesive characteristics cause the floating oil to remain on the disk.  As the disk's surface
passes under the wiper blades, the blades scrape off the oil, which is 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 typically is hauled off-site for disposal.

              Gravity separators use overflow and underflow weirs to skim a floating oil layer
from the surface of the wastewater.  The oil layer flows over the weir into a trough for  disposal or
reuse while most of the water flows underneath the weir.  A diffusion device, such as a vertical
slot weir, helps create a uniform flow through the system and increase  oil removal efficiency.

              An oil skimmer's removal efficiency depends on the composition of the waste
stream and the retention time of the water in the tank. Larger, more buoyant particles require less
retention time than do smaller particles.  The retention time necessary for 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
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amounts of surface oil. Drum and belt type skimmers are more applicable to waste streams
containing smaller amounts of floating oil.  A gravity separator in conjunction with a drum-type
skimmer effectively removes floating contaminants from nonemulsified oily waste streams.

              Coalescers remove oil droplets too finely dispersed for conventional gravity
separation-skimming technology. Coalescing also reduces the residence times (and therefore
separator sizes) required to separate oil from some wastes. The basic principle of coalescence
involves the attraction of oil droplets to the coalescing medium (typically plates). 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, and glass.

              Coalescing stages may be integrated with a wide variety of gravity oil separators,
and some  systems may incorporate several coalescing stages. A preliminary oil skimming step
avoids overloading the coalescer.

8.4.5.3        Flotation of Oils or Solids

              Air flotation combined with chemical emulsion breaking is an effective way to
treat oily wastewater containing low concentrations of metals. Flotation separates oil and grease
from the wastewater, and entrainment or adsorption will remove small amounts of metal. In
DAF, air is injected into a fluid under pressure.  The amount of air that can dissolve in a fluid
increases with increasing pressure. When the pressure is released, the  air comes out of solution
as bubbles, which attach to oil and grease molecules and "float" the oil and grease to the surface.
Induced-air flotation uses the same separation principles as DAF  systems but the gas is self-
induced by a rotor-disperser mechanism.

              Figure 8-12 shows a diagram of a DAF unit. A DAF system consists of a
pressurizing pump, air injection equipment, pressurizing tank, a pressure release valve, and a
flotation tank. DAF systems operate in two modes: full-flow pressurization and recycle
pressurization.  In full-flow pressurization, all influent wastewater is pressurized and injected
with air. The wastewater then enters the flotation unit where the pressure is relieved and bubbles
form, causing the oil and grease to rise to the surface with the air bubbles. In recycle
pressurization, part of the clarified effluent is recycled back to the influent of the DAF unit, then
pressurized and supersaturated with air.  The recycled effluent then flows through a pressure
release valve into the flotation unit. Pressurizing only the recycle reduces the amount of energy
required to pressurize the entire influent.  DAF is the  most common method of air flotation.
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                                       \
          chemical
          addition
                         Figure 8-12. Dissolved Air Flotation Unit
8.4.5.4
Ultrafiltration
              Ultrafiltration is a membrane-based process used to separate solution components
based on molecular size and shape. Under pressure, solvent and small solute species pass
through the membrane and are collected as permeate while the membrane retains larger
compounds, which are recovered as concentrate. Figure 8-5 shows a typical membrane filtration
unit.

              Ultrafiltration typically removes materials ranging from 0.002 to 0.2 microns or
molecular-weights from 500 to 300,000.  It can be used to treat oily wastewater.  Filtering the
Ultrafiltration influent removes large particles and free oil to prevent membrane damage and
fouling. Most Ultrafiltration membranes consist of homogeneous polymer or copolymer material.
The transmembrane pressure required for Ultrafiltration depends on membrane pore size, and
typically ranges between 15 to 200 psi.

              Ultrafiltration typically produces a concentrated oil phase that is two to five
percent of the influent volume. Oily concentrates typically are hauled off-site or incinerated, and
the permeate (water phase) can be  either treated further to remove water-soluble metals and
organic compounds or discharged, depending on local and state requirements.

              An Ultrafiltration system includes: pumps and feed vessels, piping or tubing,
monitoring and control units for temperature, pressure, and flow rate; process and cleaning tanks;
and membranes. Membranes  are designed specifically to handle various waste stream
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parameters, including temperature, pH, and chemical compatibility.  There are different types of
membranes, including hollow fiber, tubular, flat plate, and spiral wound. The type selected
depends on the application. For example, tubular membranes commonly separate suspended
solids, whereas spiral wound membranes separate oil from water.  Ultrafiltration systems
designed to remove oil typically are more expensive than are DAF systems.  Membranes must be
cleaned periodically to ensure effective treatment.

8.5           End-of-Pipe Wastewater Treatment and Sludge-Handling Technologies

              This subsection describes end-of-pipe technologies that MP&M facilities use for
wastewater treatment and sludge handling. Table 8-3 describes each technology and lists the
number of MP&M facilities that use the technology.  Section 8.5.1 discusses metal removal by
chemical precipitation, Section 8.5.2 discusses oil removal technologies, Section 8.5.3 discusses
wastewater polishing technologies, and Section 8.5.4 discusses sludge-handling technologies.

8.5.1          Chemical Precipitation for Metals Removal

              The most common end-of-pipe treatment technology used at MP&M facilities to
remove dissolved metals is chemical precipitation and flocculation followed by gravity
clarification.  The data in Table 8-3 show there are nearly 3,000 MP&M facilities that use
chemical precipitation and gravity settling to treat their metals-bearing wastewater.  Some
MP&M facilities use microfiltration, filter press operations, centrifuge operations, DAF, and
American Petroleum Institute (API) separation in place of clarification, but this subsection
discusses only clarification and microfiltration.  The types of equipment used for chemical
precipitation vary widely.  Small batch operations can take place in a single tank that typically
has a conical bottom to permit removal of settled solids. Continuous processes usually occur in a
series of tanks, including an equalization tank, a rapid-mix tank for dispersing the precipitating
chemicals, and a slow-mix tank for adding coagulants and flocculants and for floe formation.

              For continuous-flow systems, the first tank in the treatment train typically is the
equalization tank.  The flow equalization tank prevents upsets in processing  operations from
exceeding the hydraulic design capacity of the treatment system, improves chemical feed control,
and allows wastewater neutralization.

              Commingled wastewater from the equalization tank enters the rapid mix tank,
along with various types of precipitation chemicals added to convert the soluble metals into
insoluble compounds. Following precipitation,  the wastewater flows into a flocculation tank
where polyelectrolytes (polymers) are added, causing the precipitated solids to coagulate into
larger particles that gravity settling or other separation techniques can remove.

              Chemical precipitation is a highly reliable technology when properly monitored
and controlled. The effectiveness of this technology 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, subtle changes in operating factors (e.g., varying
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the pH, altering chemical dosage, or extending the process reaction time) may sufficiently
improve the system's efficiency.  In other cases, modifications to the treatment system are
necessary.  For example, some raw wastewater contains chemicals that may interfere with metals
precipitation, and may require additional, specialized treatment reagents such as ferrous sulfate,
sodium hydrosulfate, aluminum sulfate, or calcium chloride.  These chemicals may be added
prior to or during the precipitation process.

              Chemical precipitation systems require routine maintenance for proper operation.
This includes: calibrating instrumentation and cleaning probes; maintaining chemical pumps and
mixers (inspection, cleaning, lubrication, replacing seals and packing, replacing check valves,
cleaning strainers); and monitoring tanks and sumps (inspection, cleaning, corrosion prevention).

              There are several basic methods of performing chemical precipitation and
flocculation and many variations of each method. The four most common methods are described
below. Figure 8-13 shows a typical continuous chemical precipitation system.
               Figure 8-13.  Continuous Chemical Precipitation System with
                                    Lamella Clarifier

              Removing precipitated metals typically involves adding flocculating agents or
polymers to destabilize the hydrodynamic forces that hold the particles in suspension. For a
continuous treatment system, polymer is either added in-line between the reaction tank and the
flocculation tank, or in a small rapid mix tank between the reaction tank and flocculation tank.
In the flocculation tank, the mixer is slowed to promote agglomeration of the particles until their
density is greater than water and they settle from solution in the clarifier.
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              Hydroxide Precipitation

              Hydroxide precipitation is the most common method of removing metals from
MP&M wastewater. This process typically consists of 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 for precipitation of a divalent metal using sodium
hydroxide is shown in the following equation:

                           M2+  + 2NaOH - M(OH)2 + 2Na+                       (8-8)

              The precipitation process usually operates at a pH of between 8.5 and 11,
depending on the types of metals in the wastewater.  The pH set point for each hydroxide
precipitation system is determined by jar testing.  Jar testing results determine the optimum pH,
flocculent type and dosage to maximize the removal of target metals. Figure 8-14 shows the
effect of pH on hydroxide precipitation. Figure 8-14 was  developed based on empirical studies
using single metal solutions in reagent-free water. However, metal solubilities in complex
wastewater may  differ from those shown in the figure, and therefore facilities must test their
actual wastewater to define the minimum solubility for all metals.

              Iron Coprecipitation

              Iron coprecipitation is one method that has proven effective at reducing the
concentration of metals such as arsenic, beryllium, cadmium, copper, lead, nickel and zinc to less
than could be achieved with hydroxide precipitation alone (7).  Iron coprecipitation involves
adding an iron source such  as ferric sulfate or ferric chloride to the pH adjustment tank in the
chemical precipitation treatment system. Iron is then precipitated as iron oxyhydroxide (7).
During this process, other metal hydroxides (e.g., nickel hydroxide, copper hydroxide) may be
incorporated as an impurity within the iron oxyhydroxide  matrix or physically entrapped within
its pore spaces. Metal hydroxides may also be adsorbed to the surface of the iron oxyhydroxide
precipitate. Factors affecting the iron coprecipitation process include iron dose and iron
oxidation state, pH, the target metals oxidation state, the initial concentration of the target metal,
and competition  for adsorbent sites from other species. Facilities should conduct jar testing
using their actual wastewater to optimize the operating conditions for this process.

              Sulfide Precipitation

              The sulfide precipitation process uses equipment similar to 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 in hydroxide
precipitation. The sulfide reagents precipitate dissolved metals as metal sulfides, which often
have lower solubility limits than metal hydroxides.  Therefore, the sulfide precipitation process
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can (for many metals) achieve lower levels of residual dissolved metal in the effluent than
hydroxide precipitation treatment (see Figure 8-14). The sulfide precipitation reaction is shown
in the following equation:
                               M2+  +  FeS - MS +  Fe
2+
                             (8-9)
                    Figure 8-14.  Effect of pH on Hydroxide and Sulfide
                                    Precipitation (10)
Unlike hydroxides, sulfide can precipitate most chelated metals and can remove hexavalent
chromium without first reducing the chromium to its trivalent state.

              The major disadvantages of sulfide precipitation as compared to hydroxide
precipitation are higher capital and operating costs.  Additional disadvantages of sulfide
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precipitation are the potential for toxic hydrogen sulfide gas generation and excessive sulfide
releases in the effluent, and the generation of sulfide odors.

              Carbonate Precipitation

              Carbonate precipitation typically uses sodium carbonate (soda ash), sodium
bicarbonate, or calcium carbonate to form insoluble metal carbonates. The reaction is shown in
the following equation:


                            M2+ +  NajCC^  -  MC03 +  2Na+                      (8-10)
              Carbonate precipitation is similar in operation to hydroxide precipitation, and its
purpose is to remove metals such as cadmium or lead. For these metals, carbonate precipitation
operates at a lower pH to achieve effluent concentrations similar to those achieved by hydroxide
precipitation. Facilities sometimes operate carbonate precipitation in conjunction with hydroxide
precipitation, which may improve the overall performance of certain systems.

              Carbonate precipitation is less common than hydroxide precipitation due to the
higher cost of treatment reagents and certain operational problems, such as the release of carbon
dioxide, which can result in foaming and floating sludge.  Also, because many metal carbonates
are more soluble than are sulfides or hydroxides, this process does not effectively precipitate all
target metals.

              Chemical Precipitation Performance Factors

              Ionic strength of the wastewater is another factor that can negatively affect the
performance of the chemical precipitation system (8). As MP&M facilities lower water usage by
implementing technologies such  as flow restrictors, countercurrent cascade rinsing, and timed
rinses, the ionic strength of the wastewater reaching the treatment system will increase. In
process chemistry, a precipitate always forms or dissolves in the presence of indifferent
electrolytes. Although ions from such species do not participate directly in the solubility
equilibrium reaction, they do affect the solubility behavior of the precipitate.  The following
chemical equilibrium equations show the impact of ionic strength on the precipitation process:

                                  CA(srC(aq) + A(aq)                                (8-11)

The equilibrium constant expression for this reaction is given by

                                  (Ka)eq = (C)(A)                                    (8-12)

or

                                  (Ka)eq = gm[C]gm[A]                               (8-13)
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This equation can be rewritten as

                                   (Ke)eq = (Ka)eq/ (gm)2                                (8-14)

              The greater the concentration of indifferent electrolytes, the greater the ionic
strength of the solution and the smaller the value of the activity coefficient.  In process chemistry,
the value of g is normally less than 1.0. Therefore, the smaller the value of g, the larger the value
of (Ke)eq, indicating the solubility of the solid phase (metal hydroxide precipitate) will increase.
This means that the solubility of a precipitate will increase if the concentration of indifferent
electrolytes in solution increases (8). MP&M facilities that reduce process water usage should be
aware of these equilibria changes that will occur within their treatment system.  Facilities should
conduct additional jar testing to determine if they can mitigate the negative impacts with new
treatment chemistry or add process water to improve treatment efficiency.

              One issue raised during the MP&M public comment period was that treatment
system performance is fixed (i.e., percent removal) and therefore the effluent concentration is a
direct function of influent concentration.  The MP&M sampling episode data, however, indicate
the effluent concentration is a function  of the minimum solubility of the metal, regardless of the
influent concentration. As explained in the June 2002 NOD A (67 FR 38779), EPA reviewed
graphical displays of the paired influent and effluent values and other data analyses.  Because the
results were inconclusive and sometimes  inconsistent, EPA was unable to reach  a conclusion
about the effect of influent concentrations on the effluent concentrations.  If a facility finds that
influent concentrations appear to affect its effluent concentrations, it may be useful to perform jar
testing on a representative sample of wastewater to optimize the treatment conditions for both
high and low influent concentrations.

              After precipitation, the metal hydroxide particles are very fine and resistant to
settling. To increase their particle size  and improve their settling characteristics, 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 ferric sulfate, and a highly
diverse range of organic polyelectrolytes with varying characteristics suitable for different
wastewaters.  The type and dosage of flocculent and coagulant are based on the results of jar
testing done using the actual facility wastewater.

              Flocculated particles with  densities greater than water settle in a separate
clarification tank (e.g., a lamella clarifier), under quiescent conditions.  Operators remove the
solids from the bottom of the settling tank or clarifier, then transfer them to a thickener or other
dewatering process (see Section  8.5.4). Clarifier effluent either undergoes further processing in a
polishing unit such as a multimedia filter or discharges.
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8.5.1.1        Gravity Clarification for Solids Removal

              Gravity sedimentation to remove precipitated metal hydroxides is the most
common method of clarification (solids removal) used by MP&M facilities. Typically, two types
of sedimentation devices are used: inclined-plate clarifiers (e.g., lamella clarifiers) and circular
center-feed rim flow clarifiers.

              Lamella clarifiers contain inclined plates oriented at angles varying between 45
and 60 degrees from horizontal. As the water rises through the clarifier, the solids settle on the
plates. Clarified effluent continues to the top of the clarifier, passes over a weir, and collects in a
holding tank.  The solids collect on the inclined plates and slide downward and into the bottom
of the clarifier. When sufficient solids collect in the bottom of the clarifier, they are scraped into
a sludge hopper and then discharged, usually to a thickener.  Figure 8-13 presents a lamella
clarifier.

              Overflow rates for lamella clarifiers (i.e., between 1,000 and 1,500 gpd/ft2 for
metal hydroxide sludges) are two to four times  higher than the overflow rates for clarifiers not
equipped with inclined plates.  Clarifier inlets must be designed to distribute flow uniformly
through the tank and plate settlers. In addition, because solids can build up on plate surfaces and
adversely affect flow distribution, the clarifier should be cleaned periodically.

              Lamella clarifiers are more common at MP&M facilities than other types of
clarifiers because of the smaller area required.  They typically require only 65 to 80 percent of the
area required for clarifiers without inclined plates. Their design promotes laminar flow through
the clarifier, even when the water throughput is relatively high.

              In a center-feed  rim flow clarifier,  wastewater flows into the bottom of a center
feed well and then up into a circular tank. Heavy particles settle to the bottom of the tank where
they are raked to a discharge pipe and removed. Materials with a density less than the density  of
water float to the top of the water and are skimmed from the water surface and discharged to a
scum pit through a scum trough. Scum is removed from the scum pit periodically and then
disposed of. Clarified effluent  flows over the top of the clarifier and is collected in an effluent
channel and discharged. Figure 8-15 shows a center-feed rim flow clarifier.
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                                                 8.0 - Pollution Prevention and Wastewater Treatment Technologies
                                Operating Platform
    Scum Trough
                                                                             Overflow Weir
                                                                               Clarified Effluent
                                                                               Channel
              Scum
              Pit
                          Sludge Rake
                                          Sludge Pipe
                                                                  Influent Pipe
8.5.1.2
                       Figure 8-15. Center-Feed Rim Flow Clarifier
Microfiltration for Solids Removal
              Microfiltration is an alternative to conventional gravity clarification after chemical
precipitation. Microfiltration is a membrane-based process used to separate small suspended
particles based on size and shape.  Water and small solute species pass under pressure through a
membrane and are collected as permeate while larger particles such as precipitated and
flocculated metal hydroxides are retained by the membrane and are recovered as concentrate.
Microfiltration is similar to ultrafiltration (Section 8.4.5.4) but has a larger pore size.

              Microfiltration removes materials ranging from 0.1 to 1.0 microns (e.g.,  colloidal
particles, heavy metal particulates  and their hydroxides).  Most microfiltration membranes
consist of homogeneous polymer material.  The transmembrane pressure required for
microfiltration typically ranges between 3 to 50 psi, depending on membrane pore size.

              Microfiltration produces a concentrated suspended solid slurry that typically goes
to dewatering equipment such as a sludge thickener or a filter press. The permeate can  either be
treated further to adjust the pH or be discharged, depending on local and state requirements.
Figure 8-5 shows a typical membrane filtration system.

              The microfiltration  system includes: pumps and feed vessels; piping or tubing;
monitoring and control units for temperature, pressure, and flow rate; process and cleaning tanks;
and membranes. Membranes are designed specifically to handle various waste stream
parameters, including temperature, pH, and chemical compatibility.  Different types of
membranes are available, including hollow fiber, tubular, flat plate, and spiral wound. The
configuration selected for a particular facility depends on the type of application. For example,
tubular membranes commonly separate suspended solids, whereas spiral wound membranes
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                                               8.0 - Pollution Prevention and Wastewater Treatment Technologies

separate oils from water. Microfiltration is more expensive than conventional gravity
clarification.  Membranes must be cleaned periodically to prevent fouling and ensure effective
treatment.

8.5.1.3        Optimization of Existing Chemical Precipitation Treatment System

              Facilities can optimize the performance of an existing chemical precipitation and
clarification system using a variety of techniques such as adding equalization prior to treatment,
conducting jar testing to optimize treatment chemistry, upgrading control systems, and providing
operator training.

              Equalization

              Equalization is simply the damping of flow and concentration variations to
achieve a constant or nearly constant wastewater treatment system loading (8). Equalization
improves treatment performance by providing a uniform hydraulic loading to clarification
equipment, and by damping mass loadings, which improves chemical feed control and process
reliability. MP&M facilities implement equalization by placing a large collection tank ahead of
the treatment system. All process water and rinse water entering this tank are mixed
mechanically and then pumped or allowed to gravity flow to the treatment system at a constant
rate.  The size (volume) of the tank depends on the facility flow variations throughout the day.
Operating data collected during MP&M sampling episodes indicate hydraulic residence times for
equalization tanks average 4 to 6 hours.

              Jar Testing

              The purpose of jar testing is to optimize treatment pH, flocculant type and dosage,
the need for coprecipitants such as iron, and solids removal characteristics.  Facilities should
conduct jar testing on a sample of their actual wastewater to provide reliable information.

              Control System Upgrades

              Typical treatment system controls at MP&M facilities includes pH and ORP
controllers on alkaline chlorination systems for cyanide destruction, pH controllers on chemical
precipitation systems, flow and level monitoring equipment on equalization tanks, and solonoid
valves and metering pumps on chemical feed systems to provide accurate treatment chemical
dosing. A number of MP&M facilities have computer hardware and  software to monitor and
change treatment system operating parameters. For a number of MP&M facilities, upgrading
control equipment may reduce both pH and ORP swings caused by excess chemical dosing,
resulting in consistent effluent metals concentrations.
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                                               8.0 - Pollution Prevention and Wastewater Treatment Technologies

              Operator Training

              Having operators trained in both the theory and practical application of
wastewater treatment is key to ensuring the systems are operating at their best. Many MP&M
facilities send their operators to off-site training centers while others bring consultants familiar
with their facility's operations and wastewater treatment system to the facility to train operators.
Some of the basic elements of an operator training course should include (1):

              •      An explanation of the need for wastewater treatment, which emphasizes
                    the benefits to employees and the community;

              •      An emphasis on management's commitment to environmental
                    stewardship;

              •      An explanation of wastewater treatment terminology in simple terms;

              •      An overview of the environmental regulations that govern the facility's
                    wastewater discharges;

              •      A simple overview of wastewater treatment chemistry;

              •      Methods that can optimize treatment performance (e.g., how to conduct jar
                    testing);

              •      The test methods or parameters used to verify the system is operating
                    properly (e.g., control systems); and

              •      The importance of equipment maintenance to ensure the system is
                    operating at its maximum potential.

              First-time training for new operators may require 4 to 5 days of classroom and
hands-on study.  Experienced MP&M wastewater treatment operators should consider attending
at least 1 day of refresher training per year to update themselves on the chemistry and to learn
about new equipment on the market that may help their system's performance.

8.5.2         Oil Removal

              Operations  such as machining and grinding, disassembly of oily equipment, and
cleaning can generate wastewater containing organic machining coolants, hydraulic oils, and
lubricating oils. In addition, shipbuilding facilities may commingle oily bilge water with
wastewater from other shore-side operations, resulting in a mixed oily wastewater. Information
collected during MP&M site visits, sampling episodes,  and from the MP&M detailed surveys
showed a variety of methods to treat oily wastewater. The primary treatment technologies are
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                                                8.0 - Pollution Prevention and Wastewater Treatment Technologies
emulsion breaking and gravity flotation, emulsion breaking and DAF, and ultrafiltration.  Section
8.4 discusses these technologies.
8.5.3
Polishing Technologies
              Polishing systems remove small amounts of pollutants that may remain in the
effluent after treatment using technologies such as chemical precipitation and gravity
clarification.  These systems also can act as a temporary measure to prevent pollutant discharge
should the primary solids removal system fail due to a process upset or catastrophic event. The
following are descriptions of end-of-pipe polishing technologies that are applicable to MP&M
facilities.
8.5.3.1
Multimedia Filtration
              Sand filtration and multimedia filtration systems typically remove small amounts
of suspended solids (metal precipitates) entrained in effluent from gravity clarifiers. Sand and
multimedia polishing filters usually are designed to remove 90 percent or greater of all filterable
suspended solids 20 microns or larger at a maximum influent concentration of 40 mg/L.
Wastewater is pumped from a holding tank through the filter.  The principal design factor for the
filter is the hydraulic loading. Typical hydraulic loadings range between 4 and 5 gpm/ft2 (9).
Sand and multimedia filters are cleaned by backwashing with clean water. Backwashing is timed
to prevent breakthrough of the suspended solids into the  effluent. Figure 8-16 shows a diagram
of a multimedia filtration system.
Influent
                                                                                      Effluent
                        Figure 8-16. Multimedia Filtration System
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                                               8.0 - Pollution Prevention and Wastewater Treatment Technologies
8.5.3.2        Activated Carbon Adsorption

              Activated carbon adsorption removes dissolved organic compounds from
wastewater. Some MP&M facilities use carbon adsorption to polish effluent from ultrafiltration
systems treating oily wastewater. During adsorption, molecules of a dissolved compound adhere
to the surface of an adsorbent solid.  Activated carbon is an excellent adsorption medium due to
its large internal surface area, generally high attraction to organic pollutants, and hydrophobic
nature (i.e., water will not occupy bonding sites and interfere with the adsorption of pollutants).
Pollutants in the wastewater bond on the activated carbon grains until all the surface bonding
sites are occupied.  At that point, the carbon is considered to be "spent." Spent carbon requires
regeneration; regenerated carbon has a reduced adsorption capacity compared to fresh carbon.
After several regenerations, the carbon is disposed of.

              The carbon fits in granular carbon system vessels, forming a "filter" bed. Vessels
are usually circular for pressure systems and rectangular for gravity flow systems. For wastewater
treatment, activated carbon typically is packed into one or more  filter beds or columns; a typical
treatment system consists of multiple filter beds in series. Wastewater flows through the filter
beds and comes in  contact with all portions of the activated carbon. The activated carbon in the
upper portion of the column is spent first (assuming flow is downward), and progressively lower
regions of the column are spent as the adsorption zone moves down the unit. When pollutant
concentrations at the bottom  of the column begin to increase above acceptable levels, the entire
column is considered spent and must be regenerated or removed.

8.5.3.3        Reverse Osmosis

              Reverse osmosis is a membrane separation technology used by MP&M facilities
as an in-process step or as an end-of-pipe treatment.  Section 8.2.8.2 discusses in-process reverse
osmosis. In an end-of-pipe application, reverse osmosis typically recycles water and reduces
discharge volume rather than recovers chemicals.  The effluent from a conventional treatment
system generally has a TDS concentration unacceptable for most rinsing operations, and cannot
be recycled. Reverse osmosis with or without some pretreatment can replace TDS
concentrations, and the resulting effluent stream can be used for most rinsing operations.

8.5.3.4        Ion Exchange

              Ion  exchange is both an in-process metals recovery and recycle  and end-of-pipe
polishing technology.  Section 8.2.8.1 discusses in-process ion exchange.  This technology
generally uses cation resins to remove metals but sometimes uses both cation and anion columns.
The regenerant from end-of-pipe ion exchange is not usually amenable to metals recovery as it
typically contains multiple metals at low concentrations.
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8.5.4
8.5.4.1
                                   8.0 - Pollution Prevention and Wastewater Treatment Technologies

Sludge Handling

This subsection discusses the following sludge-handling technologies:

•      Gravity thickening;
•      Pressure filtration;
•      Sludge drying; and
•      Vacuum filtration.

Gravity Thickening
              Gravity thickening is a physical liquid-solid separation technology used to
dewater wastewater treatment sludge. Sludge feeds from a primary settling tank or clarifier to a
thickening tank, where gravity separates the supernatant (liquid) from the sludge, increasing the
sludge density. The supernatant returns to the primary settling tank or the head of the treatment
system for further treatment. The thickened sludge that collects on the bottom of the tank is
pumped to additional dewatering equipment or contract hauled for disposal.  Figure 8-17 shows a
diagram of a gravity thickener.
                         Sludge from
                  Chemical Precipitation
                    (approx. 3% solids)
                                            Supernatant Back
                                            to Chemical Precipitation
                                               Thickened Sludge to
                                               Contract Haul or to
                                               Sludge Dewatering
                                               (approx. 5% solids)
                              Figure 8-17.  Gravity Thickening
              Facilities where the sludge is to be further dewatered by a mechanical device, such
as a filter press, generally use gravity thickeners.  Increasing the solids content in the thickener
substantially reduces capital and operating costs of the subsequent dewatering device and also
reduces the hauling cost. This process is potentially applicable to any MP&M facility that
generates sludge.
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8.5.4.2
Pressure Filtration
              The filter press is the most common type of pressure filtration used at MP&M
facilities 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 8-18 shows 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 forced by the pressure of the feed pump (typically
around 100 psi) to a discharge port.  The filter cloth retains the solids, which remain in the
cavities. This process continues until the cavities are packed with sludge solids.  Some units use
an air blow-down manifold at the end of the filtration cycle to drain remaining liquid from the
system, further drying the sludge.  The pressure releases and the plates separate. 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 20 to 30 percent solids for metal
hydroxides precipitated with sodium hydroxide, and 30 to 40 percent solids for metal hydroxides
precipitated with calcium hydroxide.  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.

                                              plates
                                              and
                                             frames
     sludge
     flow in
                                   dewatered
                                   sludge (cake)
                                   unloaded
              filtrate
              flow
               out
                         Figure 8-18. Plate-and-Frame Filter Press
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                                                 8.0 - Pollution Prevention and Wastewater Treatment Technologies
8.5.4.3
Vacuum Filtration
              Some MP&M facilities conduct vacuum filtration to reduce the water content of
metal hydroxide sludge.  These MP&M facilities generally use cylindrical drum vacuum filters.
The filters on these drums typically are either made of natural or synthetic fibers, or a wire-mesh
fabric. The drum dips into a vat of sludge and rotates slowly. A vacuum inside the drum draws
sludge to the filter.  Water is drawn through the filter to a discharge port, and the dewatered
sludge is scraped from the filter. Because dewatering sludge with a vacuum filter is relatively
expensive per kilogram of water removed, the liquid sludge is frequently gravity-thickened prior
to vacuum filtration. Figure 8-19 shows a typical rotary vacuum filter.  Municipal treatment
plants and a wide variety of industries frequently use vacuum filters.  Larger facilities more
commonly use this technology, as they may have a gravity thickener to  double the solids content
of clarifier sludge before vacuum filtering.  Often facilities apply a precoat to inhibit filter
blinding.
                            Figure 8-19. Rotary Vacuum Filter

              Maintenance of vacuum filters involves cleaning or replacing the filter media,
drainage grids, drainage piping, filter parts, and other parts.  Since maintenance time may be as
high as 20 percent of total operating time, facilities may maintain one or more spare units. If this
technology is used intermittently, the facility may drain and wash the filter equipment each time
it is taken out of service.
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                                               8.0 - Pollution Prevention and Wastewater Treatment Technologies

8.5.4.4        Sludge Drying

              Wastewater treatment sludges are often hauled long distances to disposal
facilities. The transportation and disposal costs depend mostly on the volume and weight of
sludge, which is directly related to its water content. Therefore, many MP&M facilities use
sludge drying equipment following dewatering to further reduce the volume and weight of the
sludge.  The solids content of the sludge dewatered on a filter press usually ranges from 20 to 40
percent. Drying equipment can produce a waste material with a solids content of approximately
90 percent.

              There are several design variations for sludge drying equipment. A commonly
used system consists of 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 including electric, electric
infrared, steam, and  gas are used for sludge drying.  Some continuous units are designed such
that the  sludge cake  discharged from a filter press drops into the feed hopper of the 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 drying equipment requires an air exhaust system due to the
fumes generated during drying.

8.6           References

1.            Freeman, H.M. Hazardous Waste Minimization.  McGraw-Hill Publishing Co.,
              1990, p. 39.

2.            U.S. Environmental Protection Agency. Development Document for Effluent
              Limitations Guidelines and Standards for the Nonferrous Metals Forming and
              Metal Powders Point Source Category. EPA 440-1-86-019, September 1996.

3.            Cushnie, George C. Pollution Prevention and Control Technology for Plating
              Operations. National Center for Manufacturing Sciences, 1994.

4.            Brown, T. and LeMay, H. Chemistry - The Central Science, 2nd Edition. Prentice-
              Hall,  Inc., 1981, p. 360.

5.            AFCEC-TR-76-13, Final Report: Ozone Oxidation of Metal Plating Cyanide
              Wastewater. September 1976.

6.            Garrison, R.L. and Monk, C.E. "Advanced Ozone-Oxidation for Complexed
              Cyanides."  Proceedings of the First International  Symposium on Ozone for Water
              and Wastewater Treatment, 1973, p. 551.

7.            Electric Power Research Institute.  Trace Element Removal by Iron Adsorption/
              Coprecipitator: Process Design Manual.  EPRIGS-7005, October  1990.
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                                              8.0 - Pollution Prevention and Wastewater Treatment Technologies

8.            Benefield, L. and  Judkins, J. Process Chemistry for Water and Wastewater
             Treatment. Prentice-Hall, Inc., 1982, p. 110.

9.            Metcalf& Eddy, Inc. Wastewater Engineering: Treatment Disposal and Reuse.
             McGraw-Hill Book Company, 1979, p. 187.

10.           Freeman, H.M. Standard Handbook of Hazardous Waste Treatment and Disposal.
             McGraw-Hill Publishing Co., 1989.

11.           Cherry, K.F. Plating Waste Treatment. Ann Arbor Science, 1982.

12.           Evans, F.L. Ozone in Water  and Wastewater Treatment. Ann Arbor Science,
             1975.

13.           Harms, L.L. Chemicals in the Water Treatment Process. Water/Engineering and
             Management, March 1987, pg 32.

14.           Eckenfelder, W.W. Principles of Water Quality Management. CBI Publishing Co.,
             1980.

15.           Texas Natural Resource Conservation Commission. Pollution Prevention for
             Cleaning and Degreasing Operations, www.eponline.com.

16.           Ogunbameru, G. Reducing Water Used for Printed Circuit Board Manufacturing.
             Water and Wastewater Products, January 2003. www.wwp-online.com.

17.           U.S. EPA, Guidance Document for Developing Best Management Practices
             (BMP)," EPA 833-B-93-004, 1993.

18.           NDMA Source Control. Source Control Division, Orange County Sanitation
             District, California. March 27, 2002. www.ocsd.com.
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                                                                          9.0 - Technology Options

9.0           TECHNOLOGY OPTIONS

              This section presents the technology options evaluated by EPA as the basis for the
final MP&M effluent limitations guidelines and standards.  It also describes EPA's rationale for
selecting the technology options for the final rule.  EPA used the options presented in this section
as the basis for evaluating Best Practicable Control Technology Currently Available (BPT), Best
Conventional Pollutant Control Technology (BCT), Best Available Technology Economically
Achievable (BAT), New Source Performance Standards (NSPS), Pretreatment Standards for
Existing Sources (PSES), and Pretreatment Standards for New Sources (PSNS).

              EPA is promulgating performance-based limitations and standards  for the Oily
Wastes Subcategory to control direct discharges. These limitation and standards do not require
the use of any particular pollution prevention or wastewater treatment technology. Rather, a
facility may use any combination of pollution prevention and wastewater treatment technology to
comply with the limitations. Direct dischargers must also comply with NPDES regulations (40
CFR 122).

              Section 9.1 summarizes the methodology EPA used to select the technologies
included in the options.  Sections 9.2 through 9.9 describe the technology options  evaluated for
the final effluent limitations guidelines and standards for each subcategory for each of the
regulatory levels of control. Section 9.10 summarizes the options for each subcategory
considered and selected in developing the effluent limitations and standards, and Figures 9-1
through 9-6  (at the end of this section) present schematic diagrams of the options.

9.1           Technology Evaluation Methods

              Facilities performing proposed MP&M operations generate wastewater containing
oils, organic pollutants, cyanide, hexavalent chromium,  complexed metals, and dissolved
metals.1  The technology options considered for the final rule consist of pollution prevention and
wastewater treatment technologies designed to reduce or eliminate the generation  or discharge of
pollutants from facilities performing proposed MP&M operations.  EPA identified these
technologies from responses to the MP&M detailed and screener surveys, MP&M site visits and
sampling episodes, and technical literature. EPA then grouped the most common  technologies
according to the type of wastewater treated (e.g., oily wastewater, metal-bearing wastewater,
cyanide-bearing wastewater), and  also by source reduction and pollution prevention technologies,
recycling technologies, and end-of-pipe treatment technologies. Tables 8-1 through  8-3 in
Section 8.0 show the in-process and end-of-pipe treatment used by industry as reported in
industry surveys.
'Note: EPA evaluated a number of unit operations for the May 1995 proposal, January 2001 proposal, and June 2002
NODA (see Tables 4-3 and 4-4). However, EPA selected a subset of these unit operations for regulation in the final
rule (see Section 1.0). For this section, the term "proposed MP&M operations" means those operations evaluated for
the two proposals, NODA, and final rule. The term "final MP&M operations" means those operations defined as
"oily operations" (see Section 1.0, 40 CFR 438.2(f), and Appendix B to Part 438) and regulated by the final rule.

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                                                                         9.0 - Technology Options

              EPA considered a technology to be demonstrated in the industry if the technology
effectively treated wastewater from proposed MP&M operations and if EPA observed the
technology during at least one MP&M site visit or at least one survey respondent reported using
the technology. EPA evaluated the performance of each technology in terms of percent removal
and final effluent concentration using analytical data available from MP&M sampling episodes,
discharge monitoring reports and periodic compliance reports, previous effluent guidelines data
collection efforts, and quantitative and qualitative assessments from engineering site visits,
comment submittals,  and literature.

              EPA evaluated several technology options for direct dischargers in the
subcategories listed in the January 2001  proposal (i.e., General Metals, Metal Finishing Job
Shops, Printed Wiring Board, Non-Chromium Anodizing, Steel Forming and Finishing, Oily
Wastes, Railroad Line Maintenance, and Shipbuilding Dry Dock).

9.2           General Metals Subcategory

              EPA is not revising or establishing any limitations or standards for facilities that
would have been subject to this subcategory.  Such facilities will continue to be regulated by the
General Pretreatment Standards (Part 403), local limits, permit limits, and Parts 413 and/or 433,
as applicable.

9.2.1          Best Practicable Control Technology Currently Available (BPT)

              The following discussion describes the technology options considered for the
proposed General Metals Subcategory. Facilities in this proposed subcategory generate metal-
bearing wastewater but may also generate some oily wastewater (see Section 6.0).

              Option 1

              Option 1 includes segregation and preliminary treatment of oily wastewater,
cyanide-bearing wastewater,  hexavalent chromium-bearing wastewater, and complexed metal-
bearing wastewater, followed by chemical precipitation using either sodium hydroxide or lime,
sedimentation using a clarifier, and sludge removal using gravity thickening and a filter press.
Segregation of wastewater and subsequent preliminary treatment allows for the most efficient,
effective, and economical means of removing pollutants in certain wastewater streams. These
streams contain pollutants (e.g., oil and grease, cyanide, hexavalent chromium, chelated metals,
and organic solvents) that can inhibit the performance of chemical precipitation and
sedimentation treatment, while increasing the overall treatment costs. For example, if a facility
segregates its oil-bearing wastewater from its metal-bearing wastewater, then the facility can
design an oil removal treatment technology based on only the oily waste flow volume and not on
the combined metal-bearing and oil-bearing wastewater flow, decreasing the size of the overall
treatment system. Treatment chemical costs are also reduced because of the reduced volume.
Preliminary treatment technologies for these types of wastewater streams are described below.
                                           9-2

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                                                                         9.0 - Technology Options

(see Section 5.0 and Appendix C for a more detailed description of each of these wastewater
streams).

              •      Oil-Bearing Wastewater.  Alkaline cleaning wastewater and water-based
                    metal-working fluids (e.g., machining and grinding coolants) typically
                    contain significant amounts of oil and grease.  These wastewater streams
                    require preliminary treatment to remove oil and grease and organic
                    pollutants. Option 1 includes a preliminary treatment step for these
                    wastewaters consisting of chemical emulsion breaking followed by gravity
                    separation of oil and water (oil/water separator or gravity flotation).

              •      Cyanide-Bearing Wastewater.  The industry generates several types of
                    wastewater that may contain significant amounts of cyanide, such as
                    electroplating and cleaning wastewater. Option 1 includes a preliminary
                    treatment step for these wastewaters consisting of alkaline chlorination
                    with sodium hypochlorite.

              •      Hexavalent Chromium-Bearing Wastewater.  The industry generates
                    several types of wastewater that contain hexavalent chromium, usually
                    from acid treatment, anodizing, conversion coating, and electroplating.
                    Because hexavalent chromium does not form an insoluble hydroxide, this
                    wastewater requires chemical reduction of the hexavalent chromium to
                    trivalent chromium prior to chemical precipitation and sedimentation.
                    Trivalent chromium forms an insoluble hydroxide and is treated by
                    chemical precipitation and sedimentation. Option 1 includes a preliminary
                    treatment step for these wastewaters consisting of chromium reduction
                    using sodium metabisulfite.

              •      Chelated Metal-Bearing Wastewater. Electroless plating and some
                    cleaning operations generate wastewater that contains significant amounts
                    of chelated metals.  This wastewater requires chemical reduction to break
                    the metal-chelate bond or reduce the metal-chelate complex to an insoluble
                    state so that it can be removed during chemical precipitation. Option 1
                    includes a preliminary treatment  step for these wastewaters consisting of
                    chemical reduction using sodium borohydride, dithiocarbamate, hydrazine,
                    or sodium hydrosulfite.

              •      Organic Solvent-Bearing Wastewater.  Option  1 also includes contract
                    hauling of solvent degreasing wastewater, where applicable. Based on the
                    MP&M surveys and site visits, most solvent degreasing  operations that use
                    organic solvents (e.g., 1,1,1-trichloroethane, trichloroethene) are contract
                    hauled for off-site recycling. Some facilities performing proposed MP&M
                    operations reported using organic solvent/water mixtures or rinses
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                                                                          9.0 - Technology Options

                     following organic solvent degreasing. EPA found contract hauling of this
                     wastewater to be the most common disposal method for these sites.

              After pretreatment of the applicable segregated streams, the Option 1  technology
basis is chemical precipitation and gravity clarification.  Chemical precipitation adjusts 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 gravity settling process in a clarifier to remove the precipitated and
flocculated metal hydroxides. Sludge is then thickened in a gravity-thickening unit.  The sludge
is then sent to a filter press used to remove excess wastewater, which is generally recycled back
to the clarifier.

              The technology components that many facilities performing proposed MP&M
operations currently use are equivalent to those described for Option 1. Differences  in the level
of performance (i.e., effluent limitations) between current discharges and Option 1 derive from
improvements in operation and control of process operations and pollutant control technology.
EPA's technical database developed for this rule, including industry survey, site visit, and
sampling information collected during the period from 1989 through 2001, demonstrate
significant progress by the industry in reducing pollutants in wastewater discharges beyond the
existing regulatory standards. For example, sites are moving toward greater implementation of
pollution prevention and water reduction, including progression to zero discharge when possible.
In addition, improvements in treatment controls allow for more automated controls, which leads
to more consistent process operation and wastewater treatment. Finally, advances in wastewater
treatment chemicals also result in higher treatment efficiencies.

              Option 2

              Option 2 builds on Option 1 by adding the following in-process pollution
prevention, recycling, and water conservation methods that allow for recovery and reuse of
materials:

              •      Two-stage countercurrent cascade rinsing for all flowing rinses;

              •      Centrifugation and recycling of painting water curtains; and

              •      Centrifugation, pasteurization, and recycling of water-soluble machining
                     coolants.

              Option 2S

              Option 2S includes the technologies that compose Option 2 plus a sand filter after
the clarifier to further remove residual suspended solids from chemical precipitation and
clarification effluent.
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                                                                         9.0 - Technology Options

              Option 3

              In Option 3, an ultrafilter replaces the Option 1 chemical emulsion breaking and
oil/water separator to remove oil and grease, and a microfilter replaces the Option 1 clarifier.

              Option 4

              Option 4 includes the technologies in Option 3 plus the in-process flow control
and pollution prevention technologies described in Option 2, allowing recovery and reuse of
materials along with water conservation.

              Best Professional Judgment (BPJ) to Part 433 Option

              EPA also considered transferring limitations from existing Metal Finishing
effluent guidelines (40 CFR 433) to the General Metals Subcategory.  The technology basis for
Part 433 includes the following: (1) segregation of wastewater streams; (2) preliminary treatment
steps as necessary (including oils removal using chemical emulsion breaking and oil/water
separation, alkaline chlorination for cyanide destruction, reduction of hexavalent chromium, and
chelation breaking); (3) chemical precipitation using sodium hydroxide; (4) sedimentation using
a clarifier; and (5) sludge removal (i.e., gravity thickening and filter press).

              Option Selection Discussion

              As discussed in the 2001 proposal (see 66 FR 451), EPA dropped Options 1 and 3
from further consideration because Options 2 and 4, respectively, cost less and provided greater
pollutant removals. After proposal, EPA also dropped Option 4 from further consideration for
the final rule because of its increased cost and lack of significant additional pollutant removals
beyond Option 2.  In addition, comments submitted  on the proposed rule questioned the
completeness of EPA's database on microfiltration (Option 4), noting that EPA transferred
limitations for several pollutants from the Option 2 technology based on lack of data.

              EPA dropped Option 2S from further consideration for the final rule for the
reasons outlined in the 2002 Notice of Data Availability (NOD A) (67 FR 38767). First,  Option
2S results in greatly increased cost and minimal increased pollutant removals beyond Option 2.
Second, EPA believes, after incorporating additional treatment performance data and revising the
statistical methodology used for calculating numerical limitations (see Section 10.0),  the Option
2 limitations are consistently achievable without adding a sand filter.  Therefore, for the final
rule, EPA considered Option 2 and "BPJ  to Part 433 Option" as the basis for limitations  for BPT
for the General Metals Subcategory.  See Sections 11.0 and 12.0 for the final estimated
compliance costs and pollutant removals  for Option  2.

              EPA proposed to establish BPT limitations for existing direct dischargers in the
General Metals Subcategory based on the Option 2 technology. EPA  evaluated the cost of
achieving effluent reductions, pollutant reductions, and the economic  achievability of compliance
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with BPT limitations based on the Option 2 technology and the level of the pollutant reductions
resulting from compliance with such limitations. EPA has decided not to establish BPT
limitations for existing direct dischargers in the proposed General Metals Subcategory. The 2001
proposal also contains detailed discussions on why EPA rejected BPT limitations based on other
BPT technology options (see 66 FR 452).  The information in the rulemaking record for the final
rule provides no basis for EPA to change this conclusion.

              Those facilities potentially regulated in the General Metals Subcategory include
facilities that are currently subject to effluent limitations guideline regulation under 40 CFR 433
as well as facilities not currently subject to national regulation. Approximately 263 of the 266
existing General Metals  direct dischargers (estimated from survey weights for 31 surveyed
facilities) are currently covered by the Metal Finishing effluent guidelines at Part 433. The
remaining three facilities (estimated from  a survey weight for one surveyed facility) are currently
directly discharging metal-bearing wastewaters (e.g., salt bath descaling) but are not covered by
existing Metal Finishing effluent guidelines.  EPA's review of discharge monitoring data and
unit operations for this surveyed non-433 General Metals facility (with a survey weight of
approximately three) indicates that this facility is already achieving Part 433 limitations because
this facility has discharges that closely mirror those required by Part 433.

              The facilities that are currently subject to Part 433 regulations and those facilities
achieving Part 433 discharge levels, in most cases, have already installed effective pollution
control technology that includes many of the components of the Option 2 technology.
Approximately 30 percent of the direct discharging facilities in the General Metals Subcategory
currently use chemical precipitation followed by a clarifier. Further, EPA estimates that
compliance with BPT limitations based on the Option 2 technology would result in no closures
of the existing direct dischargers in the General Metals Subcategory. EPA also notes that the
adoption of this level of control would also reduce the pollutants discharged into the environment
by facilities in this Subcategory.  For facilities in the General Metals Subcategory at Option 2,
EPA estimates an annual compliance cost of $23.7 million (2001$). Using the method described
in Section 12.0 to estimate baseline pollutant loadings, EPA estimates Option 2 pollutant
removals of 417,477 pounds of conventional pollutants and 33,716 pounds of priority metal and
organic pollutants from current discharges into the Nation's waters.

              Evaluated under its traditional yardstick, EPA calculated that the effluent
reductions are achieved  at a cost of $18.1/pound-pollutant removed (2001$) for the General
Metals Subcategory at Option 2.  To estimate all pounds of pollutant removed by Option 2
technology for direct dischargers in the General Metals Subcategory, EPA used the revised
method described in Section 12.0 to estimate baseline pollutant loadings as the sum of chemical
oxygen demand (COD) pounds removed plus the sum of all metals pounds removed.  EPA used
the combination of COD pounds removed plus the sum of all metals pounds removed to avoid
any significant double counting of pollutants.

              As previously stated, EPA received many comments on its estimation of baseline
pollutant loadings and reductions for the various options presented in the January 2001 proposal.
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In response to these comments, EPA solicited comment in the June 2002 NODA on alternative
methods to estimate baseline pollutant loadings. Commentors on the NODA were generally
supportive of EPA's alternative methods to estimate baseline pollutant loadings. In particular,
commentors noted that more accurate estimates of baseline pollutant loadings could be achieved
by using DMR data. In response to these NODA comments, EPA combined the alternative
methods in the NODA into the EPA Costs & Loadings Model for the final rule (see Sections 11.0
and 12.0).

             EPA also received comment on the parameter or parameters it should use for
estimating total pounds removed by the selected technology option.  EPA selected the sum of
COD and all metals pounds removed for the final rule to compare effluent reductions and
compliance costs. This approach avoided any significant double counting of pollutants and also
provided a reasonable estimate of total pounds removed by Option 2 for the General Metals
Subcategory. Option 2 technology segregates wastewaters into at least five different waste
streams, each of which have one or two treatment steps. For example, segregated oily
wastewaters have two treatment steps under Option 2 technology as they are first treated by
chemical emulsion breaking-oil/water separation and then by chemical precipitation and
sedimentation.  These segregated wastestreams can be loosely grouped together as either oily
wastewaters or metal-bearing wastewaters.  EPA's use of COD pounds removed for Option 2
technology generally represents the removal of pollutants from the segregated oily wastewaters.
EPA's use of total metals pounds removed for Option 2 technology generally represents the
removal of pollutants from the segregated metal-bearing wastewaters.

             EPA also considered alternative parameters for calculating total  pounds removed
by Option 2 for the comparison of effluent reductions and compliance costs for the General
Metals Subcategory. In particular, EPA calculated a ratio of less than $14/pound-pollutant
removed (2001$) for the General  Metals Subcategory at Option 2 when EPA used the highest set
of pollutants removed per facility with no significant double counting of pollutants (i.e., highest
per facility pollutant removals of: (1) COD plus total metals; (2) oil and grease (as HEM) plus
total metals; or (3) oil and grease (as  HEM) plus total suspended solids (TSS)). EPA used the
highest per facility pollutant removals as a confirmation of its primary method for calculating
baseline pollutant loadings (see Section  12.0) and Option 2 for General Metals  Subcategory.

             Based on the revisions and corrections to the EPA Costs & Loadings Model
discussed in the June 2002 NODA and in Sections 11.0 and 12.0, EPA has decided not to adopt
BPT limitations based  on Option  2 technology. A number of factors supports EPA's conclusion
that BPT limitations based on Option 2 technology do not represent effluent reduction levels
attainable by the best practicable technology currently available.  As previously noted, a
substantial number of facilities that would be subject to limitations as General Metals facilities
are already regulated by BPT/BAT Part 433 limitations and other facilities are de facto Part 433
facilities if characterized by their  discharges. Thus, establishing BPT limitations for a new
General Metals Subcategory would effectively revise existing BPT/BAT limitations with respect
to those facilities. In this case, EPA felt that since the Agency is revising BPT/BAT limitations
for a significant portion of an industry, it should further review the effluent reductions achieved,
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and corresponding costs, for Option 2 technology.  Such an examination shows that, while the
Option 2 technology would remove additional pollutants at costs in the middle of the range EPA
has traditionally determined are reasonable, the costs of the additional removals of toxic
pollutants are substantially greater. In developing the final rule, EPA determined that, where a
substantial portion of a sub category is already subject to effluent limitations guidelines that
achieve significant removal, the Agency should not promulgate the proposed BPT limitations
because the limitations would achieve additional toxic removals at a cost ($l,000/pound
equivalent (PE) in 1981$) substantially greater than that EPA has typically imposed for BAT
technology in other industries (generally less than $200/PE in 1981$).

              EPA also considered transferring limitations from existing Metal Finishing
effluent guidelines (40 CFR 433) to the General Metals Subcategory. The technology basis for
Part 433 includes the following: (1) segregation of wastewater streams; (2) preliminary treatment
steps as necessary (including oils removal using chemical emulsion breaking and oil/water
separation, alkaline chlorination for cyanide destruction, reduction of hexavalent chromium, and
chelation breaking); (3) chemical precipitation using  sodium hydroxide; (4)  sedimentation using
a clarifier; and (5) sludge removal (i.e., gravity thickening and filter press).

              Approximately 99 percent of the existing direct dischargers in the General Metals
Subcategory are currently covered by the existing Metal Finishing effluent guidelines. The
remaining 1 percent (an estimated three facilities nationwide based on the survey weight
associated with one surveyed facility) are currently permitted to discharge metal-bearing
wastewaters but are not covered by the existing Metal Finishing effluent guidelines. EPA's
review of discharge monitoring data and unit operations for this surveyed  non-433  General
Metals facility (with a survey weight of approximately three) indicates that this facility is subject
to permit limitations established on a BPJ basis that are equivalent or more stringent than Part
433 limitations. Transferring limitations from existing Metal Finishing effluent guidelines would
likely result in no additional pollutant load reductions.  Therefore, based on  the lack of additional
pollutant removals that are estimated, EPA is not promulgating BPT limitations transferred from
existing Metal Finishing effluent limitations guidelines for the General Metals Subcategory.

              EPA is not revising or establishing BPT limitations for any facilities in this
Subcategory. Direct dischargers in the General Metals Subcategory will remain regulated by
permit limits and  Part  433, as applicable.

9.2.2          Best Conventional Pollutant Control Technology (BCT)

              In  deciding whether to adopt more stringent limitations for BCT than BPT, EPA
considers whether there are technologies that achieve greater removals of conventional pollutants
than those adopted for BPT, and whether those technologies are cost-reasonable under the
standards established by the CWA. EPA generally refers to the decision criteria as the "BCT cost
test." For a more detailed description of the BCT cost test and details of EPA's analysis, see
Chapter 4 of the Economic, Environmental, and Benefits Analysis of the Final Metal Products &
Machinery Rule (EEBA) (EPA-821-B-03-002).
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              As EPA is not establishing any BPT limitations for the General Metals
Subcategory, EPA did not evaluate any technologies for the final rule that can achieve greater
removals of conventional pollutants. Consequently, EPA is not establishing BCT limitations for
the General Metals Subcategory.

9.2.3          Best Available Technology Economically Achievable (BAT)

              EPA proposed to establish BAT limitations for existing direct dischargers in the
General Metals Subcategory based on the Option 2 technology.  As discussed in Section 9.2.1,
EPA has decided not to establish BPT limitations based on Option 2 technology. For the same
reasons, EPA is not establishing BAT limitations based on the same technology. EPA evaluated
the cost of effluent reductions, pollutant reductions, and the economic achievability of
compliance with BAT limitations based on the Option 2 technology.

              Based on the revisions and corrections to the EPA Costs & Loadings Model
discussed in the NOD A, preamble to the final rule, and in Sections 11.0 and 12.0, EPA
determined that the costs of Option 2 are disproportionate to the toxic pollutant reductions
(measured in PE). The cost of achieving the effluent reduction (in 1981$) for Option 2 for direct
dischargers in the General Metals Subcategory is over $1,000/PE removed (see the EEBA and
Section 26.0 of the rulemaking record, DCN 37900, for a discussion of the cost-effectiveness
analysis). The costs associated with this technology are, as previously noted, substantially greater
than the level EPA has traditionally determined are associated with available toxic pollutant
control technology. EPA has determined that Option 2 technology is not the best available
technology economically achievable for existing direct dischargers in the General Metals
Subcategory. Therefore, EPA is not revising or establishing BAT limitations for this Subcategory
based Option 2 technology.

              EPA also considered transferring BAT limitations from existing Metal Finishing
effluent guidelines (40 CFR 433.14) to the General Metals Subcategory (see "BPJ to Part 433
Option" in Section 9.2.1).  EPA reviewed existing General Metals facilities and found that all are
currently achieving Part 433  BAT  limitations.  Transferring BAT limitations from existing Metal
Finishing effluent guidelines would likely result in no additional pollutant load reductions and
minimal incremental  compliance costs (see Section 9.2.1). Therefore, based on the lack of
additional pollutant removals that are estimated, EPA is not promulgating BAT limitations
transferred from existing Metal Finishing effluent limitations guidelines for the General Metals
Subcategory.

              EPA is not revising or establishing BAT limitations for any facilities in this
Subcategory. Direct dischargers in the General Metals Subcategory will remain regulated by
permit limits and Part 433, as applicable.
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9.2.4          New Source Performance Standards (NSPS)

              EPA proposed NSPS for the General Metals Subcategory based on Option 4
technology (see Section 9.2.1). Option 4 technology is similar to Option 2 (including Option 2
flow control and pollution prevention) but includes oils removal using ultrafiltration and solids
separation by a microfilter (instead of a clarifier). Commentors stated that EPA had under-costed
the Option 4 technology and that the compliance costs would be a barrier to entry for new
facilities. In addition, commentors questioned the completeness of EPA's database on
microfiltration, noting that EPA transferred standards for several pollutants from the Option 2
technology, based on lack of data.  EPA reviewed its database for the Option 4 technology and
agrees that its microfiltration database is insufficient to support a determination that the Option 4
limitations are technically achievable.

              EPA also evaluated setting General Metals NSPS based on the Option 2
technology and assessed the financial  burden to new General Metals direct dischargers.
Specifically, EPA's 'barrier-to-entry'  analysis identified  whether General Metals NSPS based on
the Option 2 technology would pose sufficient financial burden as to constitute a material barrier
to entry of new General Metals establishments into the MP&M Point Source Category.
Additionally, EPA reviewed its database for establishing General Metals NSPS based on the
Option 2 technology as commentors indicated the proposed standards were not technically
achievable.

              In response to these comments,  EPA reviewed all the information currently
available on General Metals facilities  employing Option 2 technology. This review demonstrated
that process wastewaters at General Metals facilities contain a wide variety of metals in
significant concentrations. Commentors stated that single-stage precipitation and solids
separation steps may not achieve sufficient removals for wastewaters that contain significant
concentrations of a wide variety of metals - especially if the metals preferentially precipitate at
disparate pH ranges. Consequently, to address concerns raised by commentors, EPA also costed
new sources to operate two separate chemical precipitation and solids separation steps in series.
Two-stage chemical precipitation and solids separation allows General Metals facilities with
multiple metals to control metal discharges to concentrations lower than single-stage chemical
precipitation and solids separation over a wider pH range.

              Applying this revised costing approach, EPA projects a barrier to entry  for
General Metals NSPS based on the Option 2 technology because 14 percent of General Metals
direct dischargers have after-tax compliance costs between 1 to 3 percent of revenue, 22 percent
have after-tax compliance costs between 3 to 5 percent of revenue, and 2 percent have after-tax
compliance costs greater than 5 percent of revenue.  Consequently, based on the compliance
costs of the modified Option 2 technology, EPA rejected Option 2 technology as the basis for
NSPS in the General Metals Subcategory. See Section 11.0 for a description of how these new
source compliance costs were developed and Chapter 9 of the EEBA for a description  of the
framework EPA used for the barrier-to-entry analysis and general discussion of the results.
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              EPA also considered transferring NSPS from existing Metal Finishing effluent
guidelines (40 CFR 433.16) to the General Metals Subcategory.  EPA reviewed existing General
Metals direct dischargers and found that all are currently either covered by or have permits based
on the Metal Finishing limitations at 40 CFR 433. EPA has no basis to conclude that new
General Metals facilities would have less stringent requirements than existing facilities,
particularly since, in the absence of promulgated NSPS, it is likely that permit writers would
consult the Part 433 requirements to establish BPJ limits. In addition, those new facilities which
meet the applicability criteria for Part 433 will be subject to the NSPS for that category.
Therefore, transferring standards from these existing Metal Finishing effluent limitations
guidelines would likely result in no additional pollutant load reductions.

              Therefore, based on the lack of additional pollutant removals that are estimated,
EPA is not promulgating NSPS for the General Metals Subcategory. EPA is not revising or
establishing NSPS for any facilities in this Subcategory. Direct dischargers in the General Metals
Subcategory will remain regulated by permit limits and Part 433, as applicable.

9.2.5          Pretreatment Standards for Existing Sources (PSES)

              As discussed in the June 2002 NODA (67 FR 38798), EPA also considered a
number of alternative options whose economic impacts would be less costly than Option 2
technology.  These options potentially have compliance costs more closely aligned with toxic
pollutant reductions. EPA considered the following alternative options for the final rule:

              •      Option A:  No change in current regulation.

              •      OptionB:  Option 2 with a higher low-flow exclusion.

              •      Option  C:  Upgrading facilities currently covered by Part 413  to meet the
                    PSES of Part 433 ("413 to 433 Upgrade Option" described below).

              •      Option D:  Upgrading all facilities covered by Part 413 and those facilities
                    covered by "local limits only" that discharge greater than a specified
                    wastewater flow (e.g., 1, 3, or 6.25 million gallons per year (MGY)) of
                    process wastewater to meet the PSES of Part 433 ("Local Limits to 433
                    Upgrade Option" described below).  Note that facilities regulated by "local
                    limits only" are also regulated by the General Pretreatment Standards (40
                    CFR 403).

              413 to 433 Upgrade Option

              The 413  to 433 Upgrade Option would require those facilities currently required
to meet the standards of the Electroplating effluent limitations guidelines (40 CFR 413) to meet
the limitations and standards of the Metal Finishing effluent guidelines (40 CFR 433). Currently,
the only facilities that are still completely covered by the Electroplating effluent guidelines are
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indirect dischargers that were in existence prior to 1982 and have not significantly upgraded their
operations. Therefore, this alternative option applies to only a subset of indirect dischargers
within the proposed General Metals, Metal Finishing Job Shops, Printed Wiring Board, and Non-
Chromium Anodizing Subcategories.

              The technology components that compose the basis for the 413 to 433 Upgrade
Option are equivalent to those described for Option 1.  Differences in the level of performance
(i.e., effluent limitations) between the 413 to 433 Upgrade Option and Option 1 derive from
improvements in operation and control of process operations and pollutant control technology
since the early 1980s when the Electroplating effluent guidelines were developed.

              Local Limits to 433 Upgrade Option

              This option would upgrade all facilities covered by Part 413 and those facilities
covered by "local limits only" that discharge greater than a specified wastewater flow (e.g., 1, 3,
or 6.25 million gallons per year) of process wastewater to meet the PSES of Part 433.
Accordingly, this technology option applies to only a subset of indirect dischargers within the
proposed General Metals Subcategory. A separate but similar alternative option (see Section
9.2.1) applies to direct dischargers.

              The technology components that compose the basis for the Local Limits to 433
Upgrade Option are equivalent to those described for Option 1. Differences in treatment
performance (i.e., effluent limitations) between the Local Limits to 433 Upgrade Option and
Option 1 derive from improvements in operation and control of pollutant control technology
implemented since the early 1980s when the Electroplating effluent guidelines were developed.

              Option Selection Discussion

              EPA proposed to establish PSES for existing indirect dischargers in the General
Metals Subcategory based on the Option 2 technology  (i.e., the same technology basis that EPA
considered for BPT/BCT/BAT for this Subcategory) with a "low-flow" exclusion of 1 MGY to
reduce economic impacts on small businesses and administrative burden for control  authorities.
Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the
NOD A, preamble to the final rule, and in Sections 11.0 and 12.0, EPA rejected promulgating
PSES for existing indirect dischargers in the General Metals Subcategory based on the Option 2
technology for the following reasons: (1) many General Metals indirect dischargers are currently
regulated by existing effluent guidelines (Parts 413 or 433 or both, as applicable); (2) EPA
estimates that compliance with PSES based on the Option 2 technology will result in the closure
of approximately 4 percent of the existing indirect dischargers in this Subcategory; and (3) EPA
determined that the incremental toxic pollutant reductions are very expensive per pound removed
(the cost-effectiveness value (in 1981$) for Option 2 for indirect dischargers in the General
Metals Subcategory is $432/PE).
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              This suggests to EPA that the identified technology is not truly "available" to this
industry because it would remove a relatively small number of additional toxic pounds at a cost
significantly greater than that EPA has typically determined is appropriate for other industries.
Therefore, EPA has determined that Option 2 technology is not the best available technology
economically achievable for existing indirect dischargers in the General Metals Subcategory, and
is not establishing PSES for this subcategory based on the Option 2 technology.

              Based on the revisions and corrections to the EPA Costs & Loadings Model
discussed in the NOD A, preamble to the final rule, and in Sections 11.0 and 12.0, EPA has
revised its methodology for estimating compliance costs and pollutant loadings for Option 2,
higher low-flow exclusions (Option B),  and the "upgrade"  options (Options C and D) previously
described. Using information from this revised analysis,  EPA concludes that all of these
alternative options (Options B, C, and D) are either not available or not economically achievable.
EPA rejected Options B, C, and D because: (1) more than 10 percent of existing indirect
dischargers not covered by Part 433 close at the upgrade option; or (2) toxic removals of the
upgrade options are quite expensive (cost-effectiveness values (in  1981$) in excess of $420/PE),
suggesting that these  options are not truly available technologies for this industry segment.

              EPA consequently determined that none of the treatment options represented best
available technology  economically achievable. Therefore,  EPA is not revising or establishing
PSES for existing indirect dischargers in the General Metals Subcategory (Option A).
Wastewater discharges to POTWs from facilities in this  subcategory will remain regulated by
local limits, General Pretreatment Standards (Part 403), and Parts 413 and/or 433, as applicable.
EPA also notes that facilities regulated by Parts 413  and/or 433 PSES must comply with Part 433
PSNS if the changes to their facilities are determined to make them new sources.

9.2.6          Pretreatment Standards for New Sources (PSNS)

              In 2001, EPA proposed pretreatment  standards for new sources based on the
Option 4 technology basis.  Option 4 technology is similar to Option 2  (including Option 2 flow
control and pollution prevention) but includes oils removal using ultrafiltration and solids
separation by a microfilter (instead of a  clarifier).  As explained in Section 9.2.4, EPA concluded
that its database is insufficient to support a determination that the Option 4 standards are
technically achievable.  As a result, for the final rule, EPA  considered establishing PSNS in the
General Metals Subcategory based on the Option 2 technology (i.e., the same technology basis
that was considered for BPT/BCT/BAT for this subcategory) along with the same "low-flow"
exemption of 1 MGY considered for existing sources.

              For the final rule, EPA evaluated setting General Metals PSNS based on the
Option 2 technology and assessed the financial burden to new General Metals indirect
dischargers. Specifically, EPA's 'barrier-to-entry' analysis  identified whether General Metals
PSNS based on the Option 2 technology would pose sufficient financial burden on new General
Metals facilities to constitute a material  barrier to entry into the MP&M Point Source Category.
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              EPA projects a barrier to entry for General Metals PSNS based on the Option 2
technology because 14 percent of General Metals indirect dischargers have after-tax compliance
costs between 1 to 3 percent of revenue and 20 percent have after-tax compliance costs between
3 to 5 percent of revenue. Consequently, EPA rejected Option 2 technology as the basis for
PSNS in the General Metals Subcategory.  EPA has selected "no further regulation," and is not
revising PSNS for new General Metals indirect dischargers. Wastewater discharges to POTWs
from facilities in this subcategory will remain regulated by local limits, General Pretreatment
Standards (Part 403), and Part 433, as applicable.  See Section 11.0 for a description of how
these new source compliance costs were developed and Chapter 9 of the EEBA for a description
of the framework EPA used for the barrier-to-entry analysis and general discussion of the results.

9.3           Metal Finishing Job Shops Subcategory

              EPA is not revising any limitations or standards for facilities that would have been
subject to this subcategory. Such facilities will continue to be regulated by the General
Pretreatment Standards (Part 403), local limits, permit limits, and Parts 413 and/or 433, as
applicable.

9.3.1          BPT, BCT, and BAT

              EPA evaluated several technology options for direct dischargers for the Metal
Finishing Job Shops (MFJS) Subcategory. Facilities in this subcategory perform unit operations
that primarily generate metal-bearing wastewater, but may also generate some oily wastewater.
EPA evaluated Options 1, 2, 2S, 3, and 4, which are described in detail in Section 9.2.1. As
discussed in Section 9.2.1, EPA dropped Options 1, 2S, 3, and 4 from further consideration.
Therefore, for the final rule, EPA considered only Option 2 as the basis for limitations for the
MFJS Subcategory. See Sections 11.0 and 12.0 for the final estimated compliance costs and
pollutant loadings for Option 2.

              EPA proposed to establish BPT/BCT/BAT for existing direct dischargers in the
MFJS Subcategory based on the Option 2 technology (see Section 9.2.1 for a description of
Option 2). EPA evaluated the cost of effluent reductions, pollutant reductions, and the economic
achievability of compliance with BPT/BCT/BAT limitations based on the Option 2 technology.
Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the
NOD A, preamble to the final rule, and in Sections 11.0 and 12.0, EPA determined that the
compliance costs of the Option 2 technology are not economically achievable.

              EPA estimates that compliance with BPT/BCT/BAT limitations based on the
Option 2 technology will result in the closure of 50 percent of the existing direct dischargers in
this subcategory (12 of 24 existing MFJS direct dischargers). Consequently, EPA concludes that,
for existing direct dischargers in the MFJS Subcategory, Option 2 is not the best practicable
control technology, best conventional pollutant control technology, or best available technology
economically achievable. EPA has decided not to establish new BPT,  BCT, or BAT limitations
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for existing MFJS direct dischargers based on the Option 2 technology; these discharges will
remain subject to Part 433.

9.3.2          NSPS

              EPA proposed to establish NSPS for new direct dischargers in the MFJS
Subcategory based on the Option 4 technology. Option 4 technology is similar to Option 2
(including Option 2 flow control and pollution prevention) but includes oils removal using
ultrafiltration and solids separation by a microfilter (instead of a clarifier). As explained in
Section 9.2.4, EPA concluded that its database is insufficient to support a determination that the
Option 4 standards are technically achievable.  Consequently, EPA rejected Option 4 technology
as the basis for NSPS in the MFJS Subcategory.

              For the final rule, EPA evaluated setting MFJS NSPS based on the Option 2
technology and assessed the financial burden to new MFJS direct dischargers.  Specifically,
EPA's 'barrier-to-entry' analysis identified whether MFJS NSPS based on the Option 2
technology would pose sufficient financial burden so as to constitute a material barrier to entry
into the MP&M point source category. Additionally, EPA reviewed its database for establishing
MFJS NSPS based on the Option 2 technology as commentors indicated the proposed standards
were not technically achievable.

              In response to these comments, EPA reviewed all the information currently
available on MFJS facilities using the Option 2 technology basis. This review demonstrated that
process wastewaters at MFJS facilities contain a wide variety of metals in significant
concentrations. Commentors stated that single-stage precipitation and solids separation may not
achieve sufficient removals for wastewaters that contain significant concentrations of a wide
variety of metals, especially if the metals preferentially precipitate at disparate pH ranges.
Consequently, to address concerns raised by commentors, EPA also costed new sources to
operate two separate chemical precipitation and solids separation steps in series.  Two-stage
chemical precipitation and solids separation allows MFJS facilities with multiple metals to
control metal discharges to concentrations lower than single-stage chemical precipitation and
solids separation over a wider pH range.

              Applying this revised costing approach, EPA projects a barrier to entry for MFJS
NSPS based on the Option 2 technology because all MFJS direct dischargers have new source
compliance costs that are greater than 5 percent of revenue.  Consequently, EPA rejected Option
2 technology as the basis for NSPS in the MFJS Subcategory, and is not revising NSPS for new
MFJS direct dischargers. Wastewater discharges from these facilities in this Subcategory will
remain regulated by local limits and Part 433 NSPS as applicable.  See Section 11.0 for a
description of how these new source compliance costs were developed and Chapter 9 of the
EEBA for a description of the framework EPA used for the barrier-to-entry analysis and general
discussion of the results.
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9.3.3         PSES

             EPA evaluated several technology options for indirect dischargers for the MFJS
Subcategory, whose unit operations primarily generate metal-bearing wastewater, but may also
generate some oily wastewater. These include the same option as evaluated for BAT (i.e.,
Option 2), as well as several alternative options discussed below. EPA did not further evaluate
Options 1, 2S, 3, and 4 for the final rule for the same reasons as explained for BPT above. See
Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant loadings for Option
2 and the alternative options considered for the final rule.

             EPA proposed to establish PSES for existing indirect dischargers in the MFJS
Subcategory based on the Option 2 technology. Based on the revisions and corrections to the
EPA Costs & Loadings Model discussed in the NOD A, preamble to the final rule, and Sections
11.0 and 12.0, EPA determined that the costs of Option 2 are not economically achievable for
existing indirect dischargers in the MFJS  Subcategory. EPA estimates that compliance with
PSES based on the Option 2 technology will  result in the closure of 46 percent of the existing
indirect dischargers in this Subcategory (589  of 1,270 existing MFJS indirect dischargers), which
EPA considers to be too high. EPA has determined that Option 2 technology  is not the best
available technology economically achievable for existing indirect dischargers in the MFJS
Subcategory. Therefore, EPA is not establishing PSES for this Subcategory based on the Option 2
technology.

             As discussed in the January 2001 proposal (66 FR 551) and June 2002 NODA (67
FR 38801), EPA also considered a number of alternative options whose economic impacts would
be less costly than Option 2 technology. These options potentially have compliance costs more
closely aligned with toxic pollutant reductions. EPA considered the following alternative options
for the final rule:

             •      Option A: No change in current regulation;

             •      OptionB: Option 2 with a higher low-flow exclusion;

             •      Option C: Upgrading  facilities currently covered by Part 413 to meet the
                    PSES of Part 433 ("413 to 433 Upgrade Option" described in Section
                    9.2.5); and

             •      Option D: Pollution prevention option (see 66 FR 551).

All facilities in the MFJS Subcategory are currently subject to Part 413, Part 433 or both.

             As discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0,
based on comments, EPA has revised its methodology for estimating compliance costs  and
pollutant loadings for Option 2, low-flow exclusions (Option B), and the "upgrade" option
(Option C) previously described. Using information from this revised analysis, EPA concludes
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that neither of these alternative options (Options B or C) are economically achievable. EPA
rejected Options B and C because more than 10 percent of existing indirect dischargers not
covered by Part 433 close at the upgrade option.

             EPA also solicited comment in the January 2001 proposal on a pollution
prevention alternative for indirect dischargers in this subcategory (Option D).  Commentors
supported Option D and stated that the pollution prevention practices identified by EPA in the
January 2001 proposal represent environmentally sound practices for the metal finishing
industry. The commentors also stated that Option D should, however, be implemented on a
voluntary basis similar to the National Metal Finishing Strategic Goals Program (see 66 FR 511).
Control authorities also commented that Option D may increase their administrative burden
because of additional review of facility operations and compliance with the approved pollution
prevention plan, and enforcement of Option D may be more difficult than other options
considered.  EPA is not promulgating Option D for facilities in the MFJS Subcategory for the
final rule due to the increased administrative burden on pretreatment control authorities  and
potential problems enforcing Option D. Section 8.0 describes many of the pollution prevention
practices that were considered for Option D. These pollution prevention practices may be useful
in helping facilities lower operating costs, improve environmental performance, and foster other
important benefits.

             EPA is not establishing PSES for existing indirect dischargers in the MFJS
Subcategory. Wastewater discharges to POTWs from facilities in this subcategory will remain
regulated by General Pretreatment Standards (Part 403), and Parts 413 and/or 433, as applicable.
EPA also notes that facilities regulated by Parts 413 and/or 433 PSES must comply with Part 433
PSNS if the  changes to their facilities are determined to make them  new sources.

9.3.4         PSNS

             EPA proposed to establish PSNS for indirect dischargers in the MFJS
Subcategory based on the Option 4 technology. Option 4 technology is similar to Option 2
(including Option 2 flow control and pollution prevention) but includes oils removal using
ultrafiltration and solids separation by a microfilter (instead of a  clarifier). As explained in
Section 9.2.4, EPA concluded its database is insufficient to support a determination that the
Option 4 standards are technically achievable. Consequently, EPA rejected Option 4 technology
as the basis for PSNS in the MFJS Subcategory.

             For the final rule, EPA evaluated setting MFJS PSNS based on the Option 2
technology and assessed the financial burden to new MFJS indirect  dischargers. Specifically,
EPA's 'barrier-to-entry' analysis identified whether MFJS PSNS  based on the Option 2
technology would pose sufficient financial burden on new MFJS facilities to constitute a material
barrier to entry into the MP&M Point Source Category.

             EPA projects a barrier to entry for MFJS PSNS based on the Option 2 technology
because 8 percent of MFJS indirect dischargers have after-tax compliance costs between 1 to 3
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percent of revenue, 5 percent have after-tax compliance costs between 3 to 5 percent of revenue,
and 6 percent have after-tax compliance costs greater than 5 percent of revenue. Consequently,
EPA rejected Option 2 technology as the basis for PSNS in the MFJS Subcategory, and is not
revising PSNS for new MFJS indirect dischargers. Wastewater discharges to POTWs from
facilities in this subcategory will remain regulated by local limits, General Pretreatment
Standards (Part 403), and Part 433, as applicable. See Section 11.0 for a description of how these
new source compliance costs were developed and Chapter 9 of the EEBA for a description of the
framework EPA used for the barrier-to-entry analysis and general discussion of the results.

9.4           Non-Chromium Anodizing Subcategory

              EPA is not revising limitations or standards for any facilities that would have been
subject to this subcategory. Such facilities will continue to be regulated by the General
Pretreatment Standards (Part 403), local limits, permit limits, and Parts 413 and/or 433, as
applicable.

9.4.1          BPT, BCT, and BAT

              As previously discussed, after publication of the June 2002 NOD A, EPA
conducted another review of all Non-Chromium Anodizing (NC A) facilities in the MP&M
survey database to determine the destination of discharged wastewater (i.e., either directly to
surface waters or indirectly to POTWs or both) and the applicability of the final rule to
discharged wastewaters. As a result of this review, EPA did not identify any NCA direct
discharging facilities or NCA facilities that do not discharge wastewater (i.e., zero discharge or
contract haulers) or do not use process water (dry facilities) in its rulemaking record.  All  of the
NCA facilities in EPA's database are indirect dischargers. Therefore, EPA cannot evaluate
treatment systems at direct dischargers. As a result, EPA transferred cost and pollutant loading
data from the best performing indirect facilities in order to evaluate direct discharging limitations
in this subcategory.

              EPA evaluated several technology options for direct dischargers for the NCA
Subcategory, whose unit operations primarily generate metal-bearing wastewater, but may also
generate some oily wastewater. These include Options 1, 2, 2S, 3, and 4, which are described in
detail in Section 9.2.1.  As discussed in Section 9.2.1, EPA dropped Options 1, 2S, 3, and 4 from
further consideration. Therefore, for the final rule, EPA considered only Option 2 as the basis for
limitations for the NCA Subcategory.  See Sections 11.0 and 12.0 for the final estimated
compliance costs and pollutant loadings for Option 2.

              In 2001, EPA proposed to establish BPT/BCT/BAT limitations for direct
dischargers in the NCA Subcategory based on the Option 2 technology.  EPA evaluated the cost
of effluent reductions, quantity of pollutant reductions, and the economic achievability of
compliance with BPT/BCT/BAT limitations based on the Option 2 technology.  Based on the
revisions and corrections to the EPA Costs & Loadings Model discussed in the NOD A, preamble
to the final rule, and Sections 11.0 and 12.0, the costs of the Option 2 technology were
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disproportionate to the projected toxic pollutants reductions (cost-effectiveness values (in 1981$)
in excess of $1,925/PE).

              EPA decided not to establish BPT/BAT limitations based on the Option 2
technology for the NCA Subcategory for following reasons: (1) EPA identified no NCA direct
dischargers, and (2) the costs of Option 2 are disproportionate to the estimated toxic pollutant
reductions (i.e., $1,925/PE). EPA concludes that for existing direct dischargers in the NCA
Subcategory, Option 2 is not the best practicable control technology, best conventional pollutant
control technology, or best available technology economically achievable. EPA has decided not
to establish new BPT, BCT, or BAT limitations for existing NCA direct dischargers based on the
Option 2 technology. Although, EPA identified no NCA direct dischargers through its survey
efforts, if such facilities do exist, they would be subject to Part 433.

9.4.2          NSPS

              EPA proposed to establish NSPS for direct dischargers in the NCA Subcategory
based on the Option 2 technology. For the final rule, EPA evaluated  setting NCA NSPS based
on the Option 2 technology and assessed the financial burden to new NCA direct dischargers.
Specifically, EPA's 'barrier-to-entry' analysis identified whether NCA NSPS based on the Option
2 technology would pose sufficient financial burden on new NCA facilities to constitute a
material barrier to entry into the MP&M Point Source Category.

              EPA projects a barrier to entry for NCA NSPS based on the Option 2 technology
because approximately 26 percent of NCA direct dischargers have new source compliance costs
that are between 3 percent and 5 percent of revenue. Consequently, EPA rejected Option 2
technology as the basis for NSPS in the NCA Subcategory.  EPA has selected "no further
regulation" for new NCA direct dischargers and is not revising NSPS for  new NCA direct
dischargers, which will remain subject to Part 433.  See Section 11.0  for a description of how
these new source compliance costs were developed and Chapter 9 of the EEBA for a description
of the framework EPA used for the barrier-to-entry analysis and general discussion of the results.

9.4.3          PSES and PSNS

              EPA proposed "no further regulation" for existing and new indirect dischargers in
the NCA Subcategory. EPA based this decision on the economic impacts to indirect dischargers
associated with Option 2 and the small quantity of toxic pollutants discharged by facilities in this
Subcategory, even after a economically achievable flow cutoff is applied (see 66 FR 467).  For
the reasons set out in the 2001 proposal, EPA has decided not to establish new regulations and is
not establishing PSES or PSNS in the NCA Subcategory.  These facilities remain subject to Parts
413 or 433, or both, as applicable. EPA also notes that facilities regulated by Parts 413 and/or
433 PSES must comply with Part 433 PSNS if the changes to their facilities are determined to
make them new sources.
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9.5           Printed Wiring Board Subcategory

              EPA is not revising any limitations or standards for facilities that would have been
subject to this subcategory.  Such facilities will continue to be regulated by the General
Pretreatment Standards (Part 403), local limits, permit limits, and Parts 413 and/or 433, as
applicable.

9.5.1          BPT, BCT, and BAT

              EPA evaluated several technology options for direct dischargers for the Printed
Wiring Board (PWB) Subcategory, whose unit operations primarily generate metal-bearing
wastewater, but may also generate some oily wastewater. These include Options 1, 2, 2S, 3, and
4, which are described in detail in Section 9.2.1.  As discussed in Section 9.2.1, EPA dropped
Options 1, 2S, 3, and 4 from further consideration.  Therefore, for the final rule, EPA considered
only Option 2 as the basis for limitations for the PWB Subcategory.  See Sections 11.0 and 12.0
for the final estimated compliance costs and pollutant loadings for Option 2.

              EPA proposed to establish BPT/BCT/BAT for direct dischargers in the PWB
Subcategory based on the Option 2 technology (see Section 9.2.1 for a description of Option 2).
EPA evaluated the cost of effluent reductions,  pollutant reductions, and the economic
achievability of compliance with BPT/BCT/BAT limitations based on the Option 2 technology.

              Based on MP&M survey information, EPA estimates that compliance with
BPT/BCT/BAT limitations based on the Option 2 technology results in no closures of the
existing eight direct dischargers in the PWB Subcategory. However, EPA decided not to
establish BPT/BAT limitations based on the Option 2 technology for the PWB Subcategory for
the following reasons: (1) EPA identified only eight existing PWB direct dischargers and all of
these PWB direct dischargers are currently regulated by existing effluent guidelines (Part 433),
and (2) the  costs of Option 2 are disproportionate to the estimated toxic pollutant reductions.
EPA estimates compliance costs of $0.3 million (2001$ dollars) with only 186 toxic
pound-equivalents (PE) being removed. This equates to a cost-effectiveness value (in 1981$) of
approximately $900/PE.  EPA concludes that, for existing direct dischargers in the PWB
Subcategory, Option 2 is not the best practicable control technology, best conventional pollutant
control technology, or best available technology economically achievable. EPA has decided not
to establish new BPT, BCT, or BAT limitations for existing PWB direct dischargers based on the
Option 2 technology; these discharges will remain subject to Part 433.

9.5.2          NSPS

              EPA proposed to establish NSPS for new direct dischargers in the PWB
Subcategory based on the Option 4 technology. Option 4 technology is  similar to Option 2
(including Option 2 flow control and pollution prevention) but includes oils removal using
ultrafiltration and solids  separation by a microfilter (instead of a clarifier). As explained in
Section 9.2.4, EPA concluded that its database is insufficient to support a determination that the
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Option 4 standards are technically achievable. Consequently, EPA rejected Option 4 technology
as the basis for NSPS in the PWB Subcategory.

              For the final rule, EPA evaluated setting PWB NSPS based on the Option 2
technology.  EPA reviewed its database for establishing PWB NSPS based on the Option 2
technology as commentors indicated the proposed standards were not technically achievable.  In
response to these comments, EPA reviewed all the information currently available on PWB
facilities using the Option 2 technology basis. EPA now concludes that the PWB's Option 2
database can only be used to establish limitations for copper, nickel, and tin.  In order to assess
the difference between current NSPS requirements (from Part 433) for PWB facilities and those
under consideration in the final rule, EPA estimated the incremental quantities of copper, nickel,
and tin that would be reduced if a new PWB facility were required to meet NSPS based on the
Option 2 technology rather than NSPS based on Part 433. EPA analysis shows minimal amounts
of pollutant reductions based on more stringent requirements on copper, nickel,  and tin.

              Consequently, EPA rejected Option 2 technology as the basis for NSPS in the
PWB Subcategory based on the small incremental quantity of toxic pollutants that would be
reduced in relation to existing requirements. EPA is not establishing NSPS or revising existing
NSPS for new PWB direct dischargers. Wastewater discharges from these facilities in this
Subcategory will remain regulated by permit limits and Part 433 as applicable. See Section 11.0
for a description of how these new source compliance costs were developed and Chapter 9 of the
EEBA for a description of the framework EPA used for the barrier-to-entry analysis and general
discussion of the results.

9.5.3          PSES

              EPA evaluated several technology options for indirect dischargers for the PWB
Subcategory, whose unit operations primarily generate metal-bearing wastewater, but may also
generate some oily wastewater. These include the same option as evaluated for BAT (i.e.,
Option 2 as described in Section 9.2.1), as well as several alternative options described below.
EPA did not further evaluate Options 1, 2S, 3, and 4 for the final rule for the same reasons as
explained for BPT above.  See  Sections 11.0 and 12.0 for the final estimated compliance costs
and pollutant loadings for Option 2 and the alternative options considered for the final rule.

              EPA proposed to establish PSES for existing indirect dischargers in the PWB
Subcategory based on the Option 2 technology.  Based on the revisions and corrections to the
EPA Costs & Loadings Model discussed  in the NOD A, preamble to the final rule, and Sections
11.0 and 12.0, EPA rejected promulgating PSES for existing indirect dischargers in the PWB
Subcategory based on the Option 2 technology for the following reasons: (1) all PWB indirect
dischargers are currently regulated by existing effluent guidelines (Parts 413  or 433 or both, as
applicable); (2) EPA estimates that compliance with PSES  based on the Option 2 technology will
result in the closure of 6.5 percent of the existing indirect dischargers in this  Subcategory (55 of
840 existing PWB indirect dischargers); and (3) EPA determined that the toxic pollutant
reductions are very expensive per pound removed (the cost-effectiveness value (in 1981$) is
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$455/PE). EPA has determined that Option 2 technology is not the best available technology
economically achievable for existing indirect dischargers in the PWB Subcategory, and therefore
is not establishing PWB PSES based on the Option 2 technology.

              As discussed in the June 2002 NODA (see 67 FR 38802), EPA also considered a
number of alternative options whose economic impacts would be less costly than Option 2
technology.  These options potentially have compliance costs more closely aligned with toxic
pollutant reductions. EPA considered the following alternative options for the final rule:

              •      Option A: No change in current regulation;

              •      Option B: Option 2 with a higher low-flow exclusion; and

              •      Option C: Upgrading facilities currently covered by Part 413 to the PSES
                    of Part 433 ("413 to 433 Upgrade Option").

              EPA notes that all facilities in the PWB Subcategory are currently subject to Part
413, Part 433, or both.

              As discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0,
based on comments, EPA has revised its methodology for estimating compliance costs and
pollutant loadings for Option 2, higher low-flow exclusions (Option B), and the "upgrade" option
(Options C) previously described. Using information from this revised analysis, EPA rejected
Options B and C because:  (1) more than 10 percent of existing indirect dischargers not covered
by Part 433 close at the upgrade option; or (2) the incremental compliance costs of the upgrade
options were too great in terms  of toxic removals (cost-effectiveness values (in 1981$) in excess
of $833/PE). Therefore, EPA is not revising PSES for existing indirect dischargers in the PWB
Subcategory. Wastewater discharges to POTWs from facilities in this Subcategory will remain
regulated by General Pretreatment Standards (Part 403) and Parts 413 and/or 433, as applicable.
EPA also notes that facilities regulated by Parts 413 and/or 433 PSES must comply with Part 433
PSNS if the changes to their facilities are determined to make them new sources.

9.5.4         PSNS

              EPA proposed to establish PSNS for indirect dischargers in the PWB Subcategory
based on the Option 4 technology.  Option 4 technology is similar to Option 2 (including Option
2 flow control and pollution prevention) but includes oils removal using ultrafiltration and solids
separation by a microfilter  (instead of a clarifier).  As explained in Section 9.2.4, EPA concluded
that its database is insufficient to support a determination that the Option 4 standards are
technically achievable. Consequently, EPA rejected Option 4 technology as the basis for PSNS
in the PWB Subcategory.

              For the final rule, EPA evaluated setting PWB PSNS based on the Option 2
technology and assessed the financial burden to new PWB indirect dischargers. Specifically,
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                                                                         9.0 - Technology Options

EPA's 'barrier-to-entry' analysis identified whether PWB PSNS based on the Option 2
technology would pose sufficient financial burden on new PWB facilities to constitute a material
barrier to entry into the MP&M Point Source Category.

             EPA projects a barrier to entry for PWB PSNS based on the Option 2 technology
because 3 percent of PWB indirect dischargers have after-tax compliance costs between 1 to 3
percent of revenue and 4 percent have after-tax compliance costs greater than 5 percent of
revenue.  Consequently, EPA rejected Option 2 technology as the basis for PSNS in the PWB
Subcategory. EPA has selected "no further regulation" for new PWB indirect dischargers  and is
not revising PSNS for new PWB indirect dischargers.  Wastewater discharges to POTWs  from
facilities in this subcategory will remain regulated by local limits, General Pretreatment
Standards (Part 403), and Part 433, as applicable.  See Section 11.0 for a description of how
these new source compliance costs were developed and Chapter 9 of the EEBA for a description
of the framework EPA used for the barrier-to-entry analysis and general discussion of the  results.

9.6          Steel Forming and Finishing Subcategory

             EPA is not revising limitations or standards for any facilities that would have been
subject to this subcategory.  Such facilities will continue to be regulated by the General
Pretreatment Standards (Part 403), local limits, permit limits, and Iron and Steel effluent
limitations  guidelines (Part 420), as applicable.

9.6.1        BPT, BCT, and BAT

             EPA evaluated several technology options for direct dischargers for the Steel
Forming and Finishing (SFF) Subcategory, whose unit operations primarily generate metal-
bearing wastewater, but may also generate some oily wastewater. These include Options  1, 2,
2S, 3, and 4, which are described in detail in Section 9.2.1. As discussed Section 9.2.1, EPA
dropped Options 1, 2S, 3, and 4 from further consideration. Therefore, for the final rule, EPA
considered  only Option 2 as the basis for limitations for the SFF Subcategory.  See Sections 11.0
and 12.0 for the final  estimated compliance costs and pollutant loadings for Option 2.

             EPA proposed to establish BPT/BCT/BAT for existing direct dischargers in the
SFF Subcategory based on the Option 2 technology (see Section 9.2.1 for a description of Option
2).  For the final rule, EPA evaluated the cost of effluent reductions, pollutant reductions,  and the
economic achievability of compliance with BPT/BCT/BAT limitations based on the Option 2
technology. Based on the revisions and corrections to the EPA Costs & Loadings Model
discussed in the NOD A, preamble to the final rule, and Sections 11.0 and 12.0, EPA determined
that the compliance costs of Option 2 are not economically achievable.  EPA estimates that
compliance with BPT/BCT/BAT limitations based on the Option 2 technology will result  in the
closure of 17 percent of the existing  direct dischargers in this subcategory (7 of 41 existing SFF
direct dischargers). EPA concludes that, for existing direct dischargers in the SFF Subcategory,
Option 2 is not the best practicable control technology, best conventional pollutant control
technology, or best available technology economically achievable, and therefore, EPA is not
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establishing new BPT, BCT, or BAT limitations for existing SFF direct dischargers based on the
Option 2 technology. These facilities will remain subject to Part 420.

9.6.2          NSPS

              EPA proposed to establish NSPS for new direct dischargers in the SFF
Subcategory based on the Option 4 technology.  Option 4 technology is similar to Option 2
(including Option 2 flow control and pollution prevention) but includes oils removal using
ultrafiltration and solids separation by a microfilter (instead of a clarifier).  As explained in
Section 9.2.4, EPA concluded that its database is insufficient to support a determination that the
Option 4 standards are technically achievable. Consequently, EPA rejected Option 4 technology
as the basis for NSPS in the SFF Subcategory. EPA has selected "no further regulation" for new
SFF direct dischargers and is not revising NSPS for new SFF direct dischargers, which will
remain subject to Part 420.

9.6.3          PSES

              EPA evaluated several technology options for indirect dischargers for the Steel
Forming and Finishing Subcategory, whose unit operations primarily generate metal-bearing
wastewater, but may also generate some oily wastewater.  For the final rule, EPA considered the
same option as evaluated for BAT (i.e., Option 2).  EPA did not further evaluate Options 1, 2S,
3, and 4 for the final rule for the same reasons as explained for BPT above.  See the Development
Document for the Proposed Effluent Limitations Guidelines and Standards for the Metal
Products & Machinery Point Source Category (EPA 821-B-00-005) for the final estimated
compliance costs and pollutant loadings for Option 2.

              EPA proposed to establish PSES for existing indirect dischargers in the SFF
Subcategory based on the Option 2 technology. Based on the revisions and corrections to the
EPA Costs & Loadings Model discussed in the NOD A, preamble to the final rule, and Sections
11.0 and 12.0, EPA estimates that compliance with PSES based on the Option 2 technology will
result in the closure of 9 percent of the existing indirect dischargers in this Subcategory (10 of
112 existing SFF indirect dischargers).

              EPA has determined that Option 2 technology is not the best available technology
economically achievable for existing indirect dischargers in the SFF Subcategory, and therefore
EPA is not revising PSES for this Subcategory based on the Option 2 technology.  Wastewater
discharges to POTWs from these facilities will remain regulated by General Pretreatment
Standards (Part 403) and Part 420.

9.6.4          PSNS

              EPA proposed to establish PSNS for indirect dischargers in the SFF Subcategory
based on the Option 4 technology.  Option 4 technology is similar to Option 2 (including Option
2 flow control and pollution prevention) but includes oils removal using ultrafiltration and solids
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separation by a microfilter (instead of a clarifier). As explained in Section 9.2.4, EPA concluded
its database is insufficient to support a determination that the Option 4 standards are technically
achievable. Consequently, EPA rejected Option 4 technology as the basis for PSNS in the SFF
Subcategory.  EPA has selected "no further regulation" for new SFF indirect dischargers and is
not revising PSNS for new SFF indirect dischargers; these facilities will remain subject to Part
420.

9.7           Oily Wastes Subcategory

              EPA is promulgating limitations and standards for existing and new direct
dischargers in the Oily Wastes Subcategory based on the proposed Option 6 technology  (see
Section 9.7.1). EPA is not promulgating pretreatment standards for existing or new indirect
dischargers in this Subcategory.

9.7.1          BPT

              EPA evaluated several technology options for the direct dischargers in the Oily
Wastes Subcategory.  Each of these options is discussed below. As discussed in Section 6.0,
EPA defines the Oily Wastes Subcategory as those facilities that only discharge wastewater from
one or more oily operations (see Table 6-2 and 40 CFR 438.2(f)).

              Option 5

              Option 5 consists of end-of-pipe chemical emulsion breaking followed by gravity
separation using an oil/water separator. EPA performed sampling episodes at several facilities in
the Oily Wastes Subcategory that used chemical emulsion breaking followed by gravity  flotation
and oil skimming. These systems typically achieved a 96-percent removal of oil and grease.
Breaking the oil/water emulsion requires adding treatment chemicals such as acid, alum, and/or
polymers to change the emulsified oils or cutting fluids from hydrophilic colloids to aggregate
hydrophobic particles.  The aggregated oil particles, with a density less than water, can be
removed by gravity flotation in a coalescing plate oil/water separator.  Option 5 also includes
contract hauling of organic solvent-bearing wastewaters instead of discharge.

              Option 6

              Option 6 consists of the technologies in Option  5 plus the following in-process
flow control and pollution prevention technologies, which allow for recovery and reuse of
materials along with water conservation:

              •       Two-stage countercurrent cascade rinsing for all flowing rinses;

              •       Centrifugation and recycling of painting water curtains; and
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              •       Centrifugation, pasteurization, and recycling of water-soluble machining
                     coolants.

              Option 7

              Option 7 consists of end-of-pipe ultrafiltration, as well as contract hauling of
organic solvent-bearing wastewater instead of discharge. Sampling episode data determined that,
on average, ultrafilters will remove greater than 99 percent of all oil and grease in the influent
stream.

              Option 8

              Option 8 consists of the Option 7 technology (ultrafiltration) plus the pollution
prevention and water conservation alternatives described in Option 6.

              Option Selection

              As discussed in the 2001 proposal (66 FR 451), EPA dropped Options 5 and 7
from further consideration because Options 6 and 8, respectively, cost less and provided greater
pollutant removals.  Subsequent to proposal, EPA also dropped Option 8 from further
consideration for the final rule because of its increased cost and lack of significant additional
pollutant removals beyond Option 6.  Therefore, for the final rule, EPA considered only Option 6
as the basis for limitations for the Oily Wastes Subcategory. See Sections 11.0 and 12.0 for the
final estimated compliance costs and pollutant loadings for Option 6.

              EPA is establishing BPT pH limitations and daily maximum limitations for two
pollutants, oil  and grease as hexane extractable material (oil and grease (as HEM)) and total
suspended solids (TSS), for direct dischargers in the Oily Wastes Subcategory based on the
proposed technology option (Option 6). Option 6 technology includes the following treatment
measures: (1) in-process flow control and pollution prevention; and (2) oil/water separation by
chemical emulsion breaking and skimming (see above for additional details on the Option 6
technology).

              The Agency concluded that the Option 6 treatment technology represents the best
practicable control technology currently available and should be the basis for the BPT Oily
Wastes limitations for the following reasons.  First, this technology is available and readily
applicable to all  facilities in the Oily Wastes Subcategory. Approximately 42 percent of the
direct dischargers in the Oily Wastes Subcategory currently use the Option 6 technology.
Second, the cost of compliance with these limitations  in relation to the effluent reduction benefits
is not wholly disproportionate. None of these wastewater discharges  are currently subject to
national effluent limitations guidelines and the final rule will control wastewater discharges from
a significant number (2,382) of facilities.
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              EPA estimates that compliance with BPT limitations based on Option 6
technology will result in no closures of the existing direct dischargers in the Oily Wastes
Subcategory. Moreover, the adoption of this level of control will significantly reduce the amount
of pollutants discharged into the environment by facilities in this subcategory. For facilities in
the Oily Wastes Subcategory at Option 6, EPA estimates an annual compliance cost of $13.8
million (pre-tax, 2001$) and 480,325 pounds of conventional pollutants removed from current
discharges into the Nation's waters at a cost of $28.73/pound-pollutant removed (2001$). EPA
has, therefore, determined that the total cost of effluent reductions as a result of using the Option
6 technology are reasonable in relation to the effluent reduction benefits. (In estimating the
pounds of pollutant removed by implementing Option 6 technology for direct dischargers in the
Oily Wastes Subcategory, EPA used the sum of oil and grease (as HEM) and TSS pounds
removed to avoid  any significant double counting of pollutants).

              The 2001 proposal also contains detailed discussions explaining why EPA
rejected BPT limitations based on other BPT technology options (see 66 FR 457). The
information in the record for the final rule provides no basis for EPA to change this conclusion.

              In the  2001 proposal, EPA proposed to regulate sulfide in addition to pH, oil and
grease (as HEM),  and TSS. In the final rule, EPA has not established a sulfide limitation because
it may serve as a treatment chemical (see Section 7.0). EPA also proposed three alternatives to
control discharges of toxic organics in MP&M process wastewaters: (1) meet a numerical limit
for the total sum of a list of specified organic pollutants (similar to the Total Toxic Organic
(TTO) parameter used in the Metal Finishing effluent limitations guidelines); (2) meet a
numerical limit for total organic carbon (TOC) as an indicator parameter; or (3) develop and
certify the implementation of an organic chemicals management plan. EPA evaluated the
analytical wastewater and treatment technology data from Oily Wastes facilities and concluded it
should not establish a separate indicator parameter or control mechanism for toxic organics.
Optimizing the separation of oil and grease from wastewater using the Option 6 technology will
similarly optimize the removal of toxic organic pollutants amenable to this treatment technology.
Consequently, EPA is effectively controlling toxic organics and other priority and
nonconventional pollutant discharges in Oily Wastes Subcategory process wastewaters by
regulating oil and  grease (as HEM).

              In its analyses, EPA estimated that facilities will monitor once per month for oil
and grease (as HEM) and TSS. EPA expects that 12 data points for each pollutant per year will
yield a meaningful basis for establishing compliance with the promulgated limitations through
long-term trends and  short-term variability in oil and grease (as HEM) and TSS pollutant
discharge loading patterns.

              Although EPA is not changing the technology basis from that proposed, EPA is
revising all of the  proposed Oily Wastes Subcategory BPT limitations.  This is a result of a
recalculation of the limitations after EPA revised the data sets used to calculate the promulgated
limitations to reflect changes including corrections and additional data (see 67 FR 38754).
                                          9-27

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                                                                         9.0 - Technology Options

9.7.2          BCT

              In deciding whether to adopt more stringent limitations for BCT than BPT, EPA
considered whether there are technologies that achieve greater removals of conventional
pollutants than adopted for BPT, and whether those technologies are cost-reasonable under the
standards established by the CWA. EPA generally refers to the decision criteria as the "BCT cost
test."  EPA is promulgating effluent limitations for conventional parameters (e.g., pH, TSS, oil
and grease) equivalent to BPT for this subcategory because it identified no technologies that can
achieve greater removals of conventional pollutants than the selected BPT technology basis that
also pass the BCT cost test. EPA evaluated the addition of ultrafiltration technology to the BPT
technology basis as a means to obtain further oil and grease reductions.  However, this
technology option failed the BCT cost test. For a more detailed description of the BCT cost test
and details on EPA's analysis, see Chapter 4 of the EEBA.

9.7.3          BAT

              EPA proposed to control toxic and nonconventional pollutants by establishing
BAT limitations based on Option 6 technology. As described in Section 9.7.1, EPA has decided
not to establish BAT toxic and nonconventional limitations based on the Option 6 technology.
While the BPT limitations are cost reasonable, the additional costs associated with compliance
with Option 6-generated BAT limitations are not warranted. EPA has determined that these
costs, primarily monitoring costs, are  not warranted in view of the small quantity of additional
effluent reduction (if any) the BAT limitations would produce.  As explained above, EPA has
determined that the BPT limitation on oil and grease (as HEM) will effectively control toxic and
nonconventional discharges in Oily Wastes Subcategory process wastewaters.  EPA has not
identified any more stringent economically achievable treatment technology option beyond BPT
technology (Option 6) that it considered to represent BAT level of control applicable to Oily
Wastes Subcategory facilities.

              For the reasons explained above, EPA has concluded that it should not establish
BAT limitations for specific pollutant parameters for Oily Waste operations. EPA notes that
permit writers retain the authority to establish, on a case-by-case basis under Section
301(b)(l)(C)  of the CWA, toxic effluent limitations that are necessary to meet state water quality
standards.

9.7.4          NSPS

              EPA is promulgating NSPS that would control pH and the same conventional
pollutants controlled at the BPT and BCT levels.  The selected technology basis for NSPS for
this subcategory for the final rule is Option 6.  This is unchanged from the proposal. EPA
projects no barrier to entry for new source direct dischargers associated with Option 6 because:
(1) Option 6 technology is currently used at existing direct dischargers (i.e., Option 6 technology
is technically available), and (2) there is no barrier to entry for new sources.
                                          9-28

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                                                                         9.0 - Technology Options

              EPA evaluated the economic impacts for existing direct dischargers associated
with compliance with limitations based on Option 6 and found Option 6 to be economically
achievable (no closures projected). EPA expects compliance costs to be lower for new sources
as new sources can use Option 6 technology without incurring retrofitting costs (as is required for
some existing sources). Additionally, EPA projects no barrier to entry for Oily Wastes NSPS
based on the Option 6 technology because approximately 97 percent of Oily Wastes direct
dischargers have after-tax compliance costs less than 1 percent of revenue and 3 percent have
after-tax compliance costs between 1 to 3 percent of revenue.

              In addition, EPA also evaluated and rejected more stringent technology options
for Oily Wastes NSPS (i.e., Options 8 and 10). EPA reviewed its database for the Option 8 and
10 technologies and found that the database for Option 8 and 10 technologies is insufficient (i.e.,
no available data) or the costs are not commensurate with the pollutant removals (see 66 FR
457).

              Consequently, EPA selected Option 6 technology as the basis for NSPS in the
Oily Wastes Subcategory. See Section 11.0 for a description of how these new source
compliance costs were developed and Chapter 9 of the EEBA for a description of the framework
EPA used for the barrier-to-entry analysis and general discussion of the results.

              In addition, EPA also evaluated and rejected more stringent technology options
for Oily Wastes NSPS (i.e., Options 8 and 10). EPA reviewed its database for the Option 8 and
10 technologies and found no available data for Option 8 and 10 technologies. Since EPA's
database did not contain Option 10 treatability data from Oily Wastes facilities, EPA considered
transferring limitations for Option 10 from the Shipbuilding Dry Dock or Railroad Line
Maintenance Subcategories.  EPA ultimately rejected this approach, however, because influent
wastewaters in the Shipbuilding Dry Dock and Railroad Line Maintenance Subcategories are
generally less concentrated and contain less pollutants than wastewaters  discharged by Oily
Wastes facilities.

9.7.5         PSES

              EPA evaluated the same technology options for indirect dischargers in the Oily
Wastes Subcategory as for direct dischargers in the subcategory. For the final rule, EPA
considered the same option as evaluated for BAT (i.e., Option 6). EPA did not further evaluate
Options 5, 7, and 8 for the final rule for the same reasons as explained for BPT above.  See
Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant loadings for Option
6.

              EPA proposed to establish PSES for existing indirect dischargers in the Oily
Wastes Subcategory based on the Option 6 technology (i.e., the same technology basis that is
being promulgated for BPT/BCT/NSPS for this subcategory) with  a "low-flow" exclusion of 2
MGY to reduce economic impacts on small businesses and administrative burden for control
authorities. Based on the revisions and corrections to the EPA Costs & Loadings Model
                                          9-29

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                                                                        9.0 - Technology Options

discussed in the NOD A, preamble to the final rule, and Sections 11.0 and 12.0, and previously
discussed, EPA determined that the toxic pollutant reductions are very expensive in dollars per
toxic pounds removed.  The cost-effectiveness value (in 1981$) for Option 6 for indirect
dischargers in the Oily Wastes Subcategory is in excess of $3,500/PE removed. This suggests
that the technology is not truly "available."  EPA has determined that Option 6 technology with a
2-MGY low-flow cutoff is not the best available technology economically achievable for existing
indirect dischargers in the Oily Wastes Subcategory. Therefore, EPA is not establishing PSES
for this Subcategory based on Option 6 technology with a 2-MGY low-flow cutoff.

             As discussed in the June 2002 NODA (67 FR 38804), EPA also considered
alternative options for which economic impacts could be less costly than Option 6 technology
with a 2-MGY low-flow cutoff.  These options potentially have compliance costs more closely
aligned with toxic pollutant reductions. EPA considered the following alternative options for the
final rule:

             •      Option A:     No regulation; and
             •      OptionB:     Option 6 with a higher low-flow exclusion.

             As discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0,
based on comments, EPA has revised its methodology for estimating compliance costs  and
pollutant loadings for Option 6 with a higher low-flow exclusion (Option B). Using information
from this revised analysis, EPA concludes that none of the alternative low-flow exclusions (even
as high as 6.25 MGY) represented "available technology" because the costs associated with these
alternatives were not commensurate with the projected toxic pollutants reductions. Therefore,
EPA is not establishing PSES for existing indirect dischargers in the Oily Wastes Subcategory
(Option A). Since EPA did not identify another technology basis that was more cost-effective,
EPA is not promulgating PSES for existing indirect dischargers in the Oily Wastes Subcategory.
These facilities remain subject to the General Pretreatment Standards (40 CFR 403) and local
limits,  as applicable.

9.7.6         PSNS

             EPA proposed to establish PSNS for indirect dischargers in the Oily Wastes
Subcategory based on the Option 6 technology (i.e., the same technology basis that is being
promulgated for NSPS for this Subcategory) with a "low-flow" exclusion of 2 MGY to  reduce
economic impacts on small businesses and reduce administrative burden to POTWs.

             For the final rule, EPA evaluated setting Oily Wastes PSNS based on Option 6
technology and assessed the financial burden of Oily Wastes PSNS based on Option 6
technology on new Oily Wastes indirect dischargers.  Specifically, EPA's 'barrier-to-entry'
analysis identified whether Oily Wastes PSNS based on Option 6 technology would pose
sufficient financial burden on new Oily Wastes facilities to constitute a material barrier to entry
into the MP&M Point Source Category.
                                          9-30

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                                                                         9.0 - Technology Options

              EPA projects a barrier to entry for Oily Waste PSNS based on Option 6
technology as approximately because 1 percent of Oily Waste indirect dischargers have after-tax
compliance costs between 1 to 3 percent of revenue and 5 percent have after-tax compliance
costs between 3 to 5 percent of revenue. Consequently, EPA rejected Option 6 technology as the
basis for PSNS in the Oily Wastes Subcategory. EPA has selected "no further regulation" for
new Oily Wastes indirect dischargers and is not revising PSNS for new Oily Wastes indirect
dischargers. Wastewater discharges to POTWs from facilities in this subcategory will remain
regulated by local limits and General Pretreatment Standards (Part 403), as applicable.  See
Section 11.0 for a description of how these new source compliance costs were developed and
Chapter 9 of the EEBA for a description of the framework EPA used for the barrier-to-entry
analysis and general discussion of the results.

9.8           Railroad Line Maintenance Subcategory

              EPA is not establishing limitations or standards for any facilities that would have
been subject to this subcategory.  Permit writers and control authorities will establish  controls
using BPJ to regulate wastewater discharges from these facilities.

9.8.1          BPT

              At proposal,  EPA evaluated four technology options for the Railroad Line
Maintenance (RRLM) Subcategory.  These included Options 7 and 8, which are described in
detail in Section 9.7.1, and Options 9 and 10, described below.  In addition, for the final rule,
EPA evaluated Option 6 for this subcategory (see Section 9.7.1).

              Option 9

              Option 9 consists of end-of-pipe chemical emulsion breaking followed by
dissolved air flotation (DAF) to remove flocculated oils. This treatment train is demonstrated in
both the Shipbuilding Dry Dock and RRLM Subcategories and effectively removes emulsified
oils and suspended solids.  Option 9 also includes contract hauling of organic solvent-bearing
wastewater instead of discharge.

              Option 10

              Option 10 consists of the end-of-pipe treatment technologies included  in Option 9
plus in-process flow control and pollution prevention technologies, which allow for recovery and
reuse of materials along with water conservation.  The specific Option 10 in-process technologies
include:

              •       Two-stage countercurrent cascade rinsing for all flowing rinses;

              •       Centrifugation and recycling of painting water curtains; and
                                          9-31

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                                                                         9.0 - Technology Options

              •      Centrifugation, pasteurization, and recycling of water soluble machining
                    coolants.

              Option Selection

              For the final rule, EPA evaluated setting BPT limitations for two pollutants, TSS
and oil and grease (as HEM), for direct dischargers in the RRLM Subcategory based on a
different technology basis from that proposed in 2001. EPA proposed Option 10 technology as
the technology basis for BPT.  However, as discussed in the NOD A, EPA considered
promulgating limitations for the final rule based on the Option 6 technology for the RRLM
Subcategory (see 67 FR 38804). Option 6 technology includes the following: (1) in-process flow
control and pollution prevention; and (2) oil/water separation by chemical emulsion breaking and
skimming (see Section 9.7.1 for additional details on the Option 6 technology).

              For the RRLM Subcategory, EPA changed the technology basis considered for the
final rule based on comments and data submitted by the American Association of Railroads
(AAR). This organization is a trade association that currently represents all facilities in this
Subcategory.  As discussed in the NODA (67 FR 38755), for each RRLM direct discharging
facility known to them, AAR provided current permit limits, treatment-in-place, and summarized
information on each facility's measured monthly average and daily maximum values. AAR also
provided a year's worth of long-term monitoring data for each facility (see Section 15.1 of the
rulemaking record for the AAR surveys). This data shows that, contrary to EPA's initial findings
in the 2001 proposal, most RRLM direct dischargers treat their wastewater by chemical emulsion
breaking/oil skimming (Option 6). Based on this  updated information, EPA rejected Option 10 as
the technology basis for BPT.  The 2001 proposal also contains detailed discussions on why EPA
rejected BPT limitations based on other BPT technology options (see 66 FR 451). The
information in the rulemaking record provides no basis for EPA to change this  conclusion.

              As previously discussed, after publication of the June 2002 NODA, EPA also
conducted another review of all RRLM facilities  in the MP&M survey database to determine  the
destination of discharged wastewater (i.e., either  directly to surface waters or indirectly to
POTWs or both) and the applicability of the final rule to discharged wastewaters. As a result of
this review, EPA determined that its survey database did not accurately represent direct
dischargers in this Subcategory. Consequently, for the final rule, EPA used the information
supplied by AAR as a basis for its  analyses and conclusions on direct dischargers in this
Subcategory.

              AAR provided information on 27  facilities. EPA reviewed the information on
each of these facilities to ensure they were direct dischargers, discharged wastewaters resulting
from operations subject to this final rule, and discharged "process" wastewaters as defined by the
final rule. As a result of this review, EPA concluded that 18 of the facilities for which AAR
provided information do not directly discharge wastewaters  exclusively from oily operations (see
Section V. A of the preamble to the final rule).  Therefore, EPA's final database consists of data
for nine direct discharging RRLM  facilities. EPA considered promulgating BPT limitations for
                                          9-32

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                                                                        9.0 - Technology Options

these nine direct discharging RRLM facilities based on the Option 6 technology. The Agency
made the following conclusions during its evaluation of Option 6 for this subcategory.

             First, this technology is readily applicable to all facilities in the RRLM
Subcategory.  All direct dischargers in the RRLM Subcategory currently use wastewater
treatment equivalent or better than chemical emulsion breaking/oil skimming (Option 6).
Second, EPA estimates that compliance with BPT limitations based on Option 6 technology will
result in no closures of the existing direct dischargers in the RRLM Subcategory.  Moreover,
none of the facilities identified by AAR are small businesses as defined by the Small Business
Administration (SB A). Third, most of the RRLM facilities identified by AAR have NPDES
daily maximum permit limitations for oil and grease (as HEM) and TSS as  15 and 45 mg/L,
respectively. Based on AAR survey information, EPA concludes that these  oil and grease (as
HEM) and TSS daily maximum limits represent the average of the best performances of facilities
utilizing Option 6 technology.

             EPA evaluated the compliance costs and load reductions associated with
establishing BPT daily maximum limitations equivalent to 15 and 45 mg/L for oil and grease (as
HEM) and TSS, respectively. EPA concluded that all of the facilities identified by AAR
currently meet a daily maximum oil and grease limit of 15 mg/L and most currently monitor once
per month. Therefore, EPA estimates no pollutant load reductions and minimal incremental
annualized compliance costs for the monitoring associated with a BPT daily maximum limitation
equivalent to  15 mg/L for oil and grease (as HEM).  For TSS, with the exception of one facility,
all RRLM facilities identified by AAR currently meet a daily maximum limit of 45 mg/L. For
this one facility, EPA estimates the TSS pollutant loadings reductions associated with a BPT
daily maximum limitation equivalent to 45 mg/L to be less than 1 pound of TSS per day. Given
the fact that the few facilities in this subcategory are already essentially achieving the limitations
under consideration, EPA has determined that additional national regulation is not warranted. As
a result of this analysis, EPA concludes that it is more appropriate to address permits limitations
for this industry on a case-by-case basis and that additional national  regulation of direct
discharges in  the RRLM Subcategory at this time is unwarranted.

9.8.2        BCT

             In deciding whether to adopt more stringent limitations for BCT than BPT, EPA
considers whether there are technologies that achieve greater removals of conventional pollutants
than adopted for BPT, and whether those technologies are cost-reasonable under the standards
established by the CWA. EPA generally refers to the decision criteria as the "BCT cost test." For
a more detailed description of the BCT cost test and details of EPA's analysis, see Chapter 4 of
the EEBA.

             For the reasons discussed above, EPA is not establishing BCT limitations for the
RRLM Subcategory.
                                          9-33

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                                                                        9.0 - Technology Options

9.8.3          BAT

              As proposed, EPA is not establishing BAT regulations for the RRLM
Subcategory. EPA did not propose BAT regulations because the Agency concluded that facilities
in this subcategory discharge very few pounds of toxic pollutants. EPA estimates that six
facilities discharge 34 PE per year to surface waters, or about 6 PE per year per facility. The
Agency based the loadings calculations on EPA sampling data, which found very few priority
toxic pollutants at treatable levels in raw wastewater.  EPA has received no data or information
during the rulemaking that contradicts these conclusions. Therefore, nationally applicable
regulations for toxic and nonconventional pollutants are unnecessary at this time and direct
dischargers will remain subject to permit limitations for toxic and nonconventional pollutants
established on a case-by-case basis using BPJ.

9.8.4          NSPS

              EPA proposed setting NSPS based on Option 10 technology for this subcategory.
For the final rule, EPA considered setting RRLM NSPS based on Option 10 technology and
assessed the financial burden of RRLM NSPS based on  Option  10 technology on new RRLM
direct dischargers.  Specifically, EPA's 'barrier-to-entry' analysis identified whether RRLM
NSPS based on Option  10 technology would pose sufficient financial burden as to constitute a
material barrier to entry into the MP&M Point Source Category.

              EPA projects no barrier to entry for RRLM NSPS based on Option 10 technology
because: (1) Option 10 technology is currently used at existing RRLM direct dischargers (i.e.,
Option 10 technology is technically available), and (2) all RRLM direct dischargers have new
source compliance costs that are less than 1 percent of revenue.  However, EPA is not
promulgating RRLM NSPS based on the Option 10 technology  because EPA concludes that it is
more appropriate to address limitations for this industry on  a case-by-case basis and that national
regulation of direct discharges in the RRLM Subcategory at this time is unwarranted. See
Section  11.0 for a description of how these new source compliance costs were developed and
Chapter 9 of the EEBA for a description of the framework EPA used for the barrier-to-entry
analysis and general discussion of the results.

9.8.5          PSES and PSNS

              EPA proposed not to establish pretreatment standards for existing and new
indirect dischargers in the RRLM Subcategory based on the small quantity of toxic pollutants
discharged to the environment (after POTW treatment) by facilities in this subcategory (i.e.,
approximately 2 PE removed annually per facility (see 66 FR 470-471)). For the same reasons
set out in the 2001 proposal, EPA is not promulgating pretreatment standards for existing or new
indirect dischargers in this subcategory. These facilities remain subject to the General
Pretreatment Standards (40 CFR 403) and local limits.
                                          9-34

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                                                                         9.0 - Technology Options

9.9           Shipbuilding Dry Dock Subcategory

              EPA is not establishing limitations or standards for any facilities that would have
been subject to this subcategory.  Permit writers and control authorities will establish controls
using BPJ to regulate wastewater discharges from these facilities.

9.9.1          BPT/BCT/BAT/NSPS

              EPA evaluated four technology options for the Shipbuilding Dry Dock (SDD)
Subcategory.  These include Options 7 and 8, which are described in detail in Section 9.7.1, and
Options 9 and 10, which are described in detail in Section 9.8.1.

              As discussed in the 2001 proposal (66 FR 451), EPA dropped Options 7 and 9
from further consideration because Options 8 and 10, respectively, cost less and provided greater
pollutant removals.  EPA also evaluated and rejected a more stringent technology option for SDD
NSPS (i.e., Option 8). EPA reviewed its database for the Option 8 technology and found that no
available data or possibility of data transfer from the other oily subcategories are available
because ultrafiltration does not consistently show a better removal than Option 10 to support a
determination that NSPS based on Option 8 standards are technically achievable.  EPA
concluded that Option 8 does not represent the best  practicable control technology. Therefore,
for the final rule, EPA considered only Option 10 as the basis for limitations for the SDD
Subcategory.  See Sections  11.0 and 12.0 for the final estimated compliance costs and pollutant
loadings for Option 10.

              At the time of the 2001  proposal, EPA identified six direct discharging SDD
facilities with multiple discharges. Based on the information in the database at that time,
discharges from these facilities contained minimal concentrations of toxic organic and metals
pollutants (<9 PE/facility), but substantial quantities of conventional pollutants, particularly oil
and grease. Consequently, EPA proposed to establish BPT limitations and NSPS for only two
pollutants, TSS and oil and grease (as HEM), for direct dischargers in the SDD Subcategory
based on Option 10 technology. This technology includes the following:  (1) in-process flow
control and pollution prevention, and (2) oil/water separation by chemical emulsion breaking and
oil/water separation by dissolved air flotation (see Section 9.8.1). EPA proposed this technology
basis because some existing SDD facilities use this technology and it projected significant
reductions in conventional pollutants and determined that these reductions were cost reasonable.

              Following proposal, EPA received comments and supporting data indicating that
its estimates of current pollutant discharges from this subcategory were overestimated. In
particular, commentors claimed that current discharges of oil and grease were minimal and that
national regulation was not warranted for this subcategory.

              For the final  rule, EPA incorporated the additional information provided by
commentors into its analysis.  EPA continues to conclude that there are six direct discharging
SDD facilities. However, EPA now concludes that  direct discharges from these facilities
                                          9-35

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                                                                         9.0 - Technology Options

generally contain minimal levels of all pollutants. In particular, EPA's database indicates that
regulation of oil and grease in direct discharges from SDD facilities is unwarranted because
current oil and grease discharges from these facilities are not detectable (< 5 mg/L) or nearly not
detectable. EPA has similarly determined that it should not establish nationally applicable
limitations and standards for TSS because TSS discharges are, on average, minimal.  The data
show that TSS discharges may increase episodically, particularly when the dry dock is
performing abrasive blasting operations cleaning. However, EPA has concluded that these
episodic discharges from six facilities do not warrant national regulation.

              Therefore, nationally applicable regulations for new and existing SDD direct
dischargers are unnecessary at this time and these facilities will remain subject to permit
limitations established on a case-by-case basis using BPJ.

9.9.2         PSES and PSNS

              EPA proposed not to establish pretreatment standards for existing and new
indirect dischargers in the SDD  Subcategory based on the small number of facilities in this
subcategory and on the small quantity of toxic pollutants removed by the technology options
evaluated by EPA at proposal (i.e., less than 26 PE removed annually per facility (see 66 FR
471)). For the same reasons set out in the 2001  proposal, EPA is not promulgating pretreatment
standards for existing or new indirect dischargers in this subcategory. These facilities remain
subject to the General Pretreatment Standards (40 CFR 403) and local limits.

9.10          Summary of Technology Options Considered and Selected for the Final
              MP&M Rule

              Table 9-1  summarizes all of the technology options considered for the MP&M
subcategories for either the proposed or final rules.  Table 9-2 summarizes EPA's selected
technology bases for the final rule.
                                          9-36

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                                                                                                                                                  9.0 - Technology Options
                                                                                Table 9-1
                                                            Technology Options  by Subcategory
Treatment or Source Reduction Technology
Chemical Precipitation
Gravity Clarification for Metal Hydroxide Removal
Microfiltration for Metal Hydroxide Removal
Chemical Emulsion Breaking Followed by Gravity
Separation for Oil Removal
Ultrafiltration for Oil Removal
Chemical Emulsion Breaking Followed by Dissolved Air
Flotation for Oil Removal
Alkaline Chlorination for Cyanide Removal
Chemical Reduction of Hexavalent Chromium
Chelation Breaking/Precipitation to Remove Complexed
Metals
Contract Hauling of Organic Solvent-Bearing
Wastewater Instead of Discharge
Countercurrent Cascade Rinsing to Conserve Water
Centrifugation of Painting Water Curtains to Extend Life
Centrifugation and Pasteurization of Machining
Coolants to Extend Life
Sand Filter to Remove Additional Suspended Solids
Sludge Dewatering and Disposal
Technology Options Considered for the General Metals, Metal Finishing
Job Shops, Printed Wiring Board, Steel Forming and Finishing, and Non-
Chromium Anodizing Subcategories"
1
/
/

/


/
/
/
/




/
2
/
/

/


/
/
/
/
/
/
/

/
2S
/
/

/


/
/
/
/
/
/
/
/
/
3
/

/

/

/
/
/
/




/
4
/

/

/

/
/
/
/
/
/
/

/
413 to 433
Upgrade
/
/

/


/
/
/
/




/
Local Limits
to 433
Upgrade
/
/

/


/
/
/
/




/
Technology Options Considered for the Oily
Wastes, Shipbuilding Dry Dock, and Railroad
Line Maintenance Subcategories'
5



/





/





6



/





/
/
/
/


7




/




/





8




/




/
/
/
/


9





/



/




/
10





/



/
/
/
/

/
VO
        "See Section 9.2.2 for a discussion of BCT options considered for the General Metals Subcategory.
        bEPA evaluated Option 5 for the Oily Wastes Subcategory only, Option 6 for the Oily Wastes and Railroad Line Maintenance Subcategories only, and Options 9 and 10 for the Shipbuilding Dry Dock
        and Railroad Line Maintenance Subcategories only. See Sections 9.7.2, 9.8.2, and 9.9.1 for discussions of BCT options considered for these subcategories.

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                                                9.0 - Technology Options
                   Table 9-2
Summary of Technology Bases for the Final Rule
Subcategory
General Metals
Metal Finishing Job Shops
Printed Wiring Board
Non-Chromium Anodizing
Steel Forming and
Finishing
Oily Wastes
Railroad Line Maintenance
Shipbuilding Dry Dock
Regulatory Level
BPT/BCT/BAT/NSPS
PSES/PSNS
BPT/BCT/BAT/NSPS
PSES/PSNS
BPT/BCT/BAT/NSPS
PSES/PSNS
BPT/BCT/BAT/NSPS
PSES/PSNS
BPT/BCT/BAT/NSPS
PSES/PSNS
BPT/BCT/NSPS
BAT
PSES/PSNS
BPT/BCT/BAT/NSPS
PSES/PSNS
BPT/BCT/BAT/NSPS
PSES/PSNS
Technology Basis
No new or revised limitations or standards established
No new or revised standards established
No new or revised limitations or standards established
No new or revised standards established
No new or revised limitations or standards established
No new or revised standards established
No new or revised limitations or standards established
No new or revised standards established
No new or revised limitations or standards established
No new or revised standards established
Option 6: In-process pollution prevention, recycling,
and water conservation methods; and chemical emulsion
breaking followed by oil/water separation
No new or revised limitations established
No new or revised standards established
No new or revised limitations or standards established
No new or revised standards established
No new or revised limitations or standards established
No new or revised standards established
                      9-38

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VO
OJ
VO
                                                                                                                    9.0 - Technology Options
                General Metal-Bearing
                   Wastewater
                                 Reducing Agent
Hexavalent Chromium- w
Bearing Wastewater *~
Chromium
Reduction





>,
•
Oxidizing Agent
1
Cyanide-Bearing ^
Wastewater
Cyanide
Destruction


Emulsion Breaking Agent
Oily Wastewater w

Chemical
Emulsion
Breaking
>,


Oil to Reclaim
Chemical
Emulsion
Breaking

•w



Precipitation and
Flocculation Chemicals
•w
>
k '
Filtrate
Chemical
Precipitation

Sludge
Dewatering
1— i
Solids Removed
Clarification
Sludge
^ Sludge to
Disposal
                                                                                                                  Wastewater
                             Reducing/Precipitation Agent
Chelated Metal- w
Bearing Wastewater
Chelated
Metals
Treatment


Solvent-Bearing
Wastewater
'

Contract
Hauling
                                                  . Off-Site Treatment
                                                    and Disposal
                Figure 9-1.  End-of-Pipe Treatment Train for Options 1 and 2 Considered for the Following Subcategories:
                 General Metals, Metal Finishing Job Shops, Non-Chromium Anodizing, Printed Wiring Board, and Steel
                                                          Forming and Finishing

-------
                                                                                                                      9.0 - Technology Options
                                          Countercurrent
                                          Cascade Rinse
                         Fresh
                         Water
VO
-U
o
Discharge to
 Treatment
                                                                                       Recycled Water
                                                                                                                    Discharge to
                                                                                                                    Treatment
                                                                                        Wastewater
                                                                                                         Paint
                                                                                                        Sludge
                                                                                                         Oilto
                                                                                                        Reclaim
                                                                                                                    Discharge to
                                                                                                                    Treatment or
                                                                                                                     Disposal
                                                                                        Spent Cooling
                                                                                                        Sludge
                     Figure 9-2. In-Process Water Use Reduction Technologies for Options 2 and 4 Considered for the
                           Following Subcategories: General Metals, Metal Finishing Job Shops, Non-Chromium
                                    Anodizing, Printed Wiring Board, and Steel Forming and Finishing

-------
                  General Metal-Bearing
                      Wastewater
                                    Reducing Agent
vo
                                                                                                                      9.0 - Technology Options
Hexavalent Chromium- w
Bearing Wastewater ^
Cyanide-Bearing .
Wastewater ^
Oily Wastewater w

Chromium
Reduction
Oxidizing Agen
I
Cyanide
Destruction
Oil to Reclaim
t
Ultrafiltration

t
>,
-w



Precipitation and
Flocculation Chemicals
w
>
k
Filtrate
Chemical
Precipitation

Sludge
Dewatering
1— »
> Solids Removed
by Microfiltration
Sludge
^. Sludge to
Disposal

                                                                                                                   Wastewater
                                                                                                                    Discharge
                                Reducing/Precipitation Agent
Chelated Metal- -
Bearing Wastewater
Chelated
Metals
Treatment
>,

                    Solvent-Bearing
                      Wastewater
Off-Site Treatment
  and Disposal
                Figure 9-3. End-of-Pipe Treatment Train for Options 3 and 4 Considered for the Following Subcategories:
                 General Metals, Metal Finishing Job Shops, Non-Chromium Anodizing, Printed Wiring Board, and Steel
                                                           Forming and Finishing

-------
                                                                  9.0 - Technology Options
                    Polymer,
                     Alum,
                     Acid
   Oilto
  Reclaim
Oily
Wastewater w

>
f
Chemical
Emulsion
Breaking
>,

i
k
Gravity
Oil/Water
Separation
Wastewater
Discharge w

Figure 9-4.  End-of-Pipe Treatment Train for Options 5 and 6 Considered for the
     Following Subcategories: Oily Wastes and Railroad Line Maintenance
                                 Oil to Reclaim
                                     11
             Oily Wastewater
                                 Ultrafiltration
Wastewater Discharge
         Figure 9-5. End-of-Pipe Treatment Train for Option 7 and 8
          Considered for the Following Subcategories: Oily Wastes,
             Railroad Line Maintenance, Shipbuilding Dry Dock
                                    9-42

-------
                                                                   9.0 - Technology Options
                     Polymer,
                      Alum,
                       Acid
 Oilto
Reclaim
Oily
Wastewater w

>
f
Chemical
Emulsion
Breaking
>,

i
k
Dissolved
Air
Flotation
Wastewater
Discharge w

   Figure 9-6.  End-of-Pipe Treatment Train for Options 9 and 10 Considered for
the Following Subcategories: Railroad Line Maintenance and Shipbuilding Dry Dock
                                     9-43

-------
                                                 10.0 - Limitations and Standards: Data Selection and Calculation

10.0          LIMITATIONS AND STANDARDS: DATA SELECTION AND
              CALCULATION

              This section describes the data sources, data selection, data conventions, and
statistical methodology used by EPA in calculating the long-term averages, variability factors,
and daily maximum limitations. The effluent limitations and standards1 are based on long-term
average effluent values and variability factors that account for variation in treatment performance
within a particular treatment technology over time. As explained in the preamble to the rule,
EPA is promulgating daily maximum limitations only for the Oily Wastes Subcategory. This
section describes the data selection and calculations for the daily maximum limitations for total
suspended solids (TSS) and oil and grease measured as w-hexane extractable material (O&G).

              Section 10.1 gives a brief overview of data  sources (a more detailed discussion is
provided in Chapter 3) and describes EPA's evaluation and selection of episode data sets that are
the basis of the limitations.  Section  10.2 provides a more detailed discussion of the selection of
the episodes and data for each pollutant.  Section 10.3 presents the procedures for data
aggregation.  Section 10.4 provides an  overview of the daily maximum limitations.  Section 10.5
describes the procedures for and summary of the estimation of long-term averages, variability
factors,  and limitations.  Section 10.6 presents an evaluation of the limitations.

10.1          Overview of Data  Selection

              To develop the long-term  averages, variability factors, and limitations, EPA used
concentration data from facilities with the Option 6 technology in the Oily Wastes Subcategory.
These data were collected from two sources, EPA's sampling episodes and self-monitoring data.

              All sampling episodes were conducted using the EPA sampling and chemical
analysis protocols as described in Section 3.3.  Sampling episode reports maintained in the
rulemaking record present the data collected during each sampling episode.

              In comments on the proposal and from other sources, EPA received compliance
monitoring data from industry. These data are sometimes referred to as 'Discharge Monitoring
Report'  (DMR) or self-monitoring data.  EPA denoted these data with a 'D' appended to the 4-
digit episode identifier, the same 4-digit number used for EPA sampling data at that facility.  In
the statistical analyses, the self-monitoring data are treated separately from the EPA sampling
data.  This practice is consistent with other guidelines and  is used because the data tend to be
associated with different time periods and/or analytical methods than EPA sampling data.

              Following the 2001 proposal and 2002 NOD A, EPA received many comments on
its selection  of facilities and datasets used as the basis of its limitations. In response to these
comments, EPA revisited its selection of facilities operating the  Option 6 technology in the Oily
Wastes  Subcategory. As discussed in Section 10.2, for the episode datasets that were used to
'In the remainder of this chapter, references to 'limitations' includes 'standards.'

                                          10-1

-------
                                                 10.0 - Limitations and Standards: Data Selection and Calculation

develop the final MP&M limitations, EPA performed a detailed review of the data and all
supporting documentation accompanying the data. This was done to ensure that the selected data
represent a facility's normal operating conditions and that the data accurately reflect the
performance expected by the production method and treatment systems. Thus, EPA evaluated
whether the data were collected while a facility was experiencing exceptional incidents (upsets).

              EPA also examined the range of unit operations covered by the facilities.  As part
of its detailed review, EPA verified that it had  selected facilities that generated wastewater that
encompassed the unit operations that generated the most concentrated types of wastewater in the
Oily Wastes Subcategory. (Section IV.A.3.6 of the preamble to the final rule identifies the unit
operations in the Oily Wastes Subcategory.)

              In evaluating the data for the rule, EPA relied on two major sources of data:
sampling episode reports and data review narratives.

              The sampling episode report (SER) describes the collection, analysis, and results
of EPA's comprehensive sampling at a facility in support of effluent guidelines rulemakings.
Each SER presents a general overview of facility operations, includes process diagrams of
treatment  operations, summarizes the sample fractions collected for each sample point, describes
any deviations from the sampling and analysis  plan, provides flow and production information,
and lists the analytical data results.  SERs  are located in Sections 5.2 and 15.3 of the record.

              The data review narratives  (DRNs) present an assessment of the quality of the
analytical  (chemical) data, based upon a five-stage review process.  The DRNs are included as an
attachment to each SER. Because the data are  the basis of the limitations, EPA determined that
an additional evaluation of the laboratory submissions was appropriate. As a result of that
evaluation, EPA confirmed that its previous determinations were appropriate for the TSS  data
and most oil and grease data.  As explained in  Section 10.2, EPA excluded  some oil and grease
data as a result of the evaluation.  (See DCN 36500 in Section 28.5 of the record for a summary
of the evaluation.)

10.2          Episode and Data Selection

              This section describes the episodes selected for EPA's evaluations of the
technology option for the Oily Wastes Subcategory. Table 10-1 summarizes the episode and
sample point selections,  and Table 10-2 identifies the unit operations for each facility.
                                          10-2

-------
                                                                                        10.0 - Limitations and Standards: Data Selection and Calculation
                                                             Table 10-1
                                        Oily Wastes Subcategory Oil/Water Separation


Episode
No.
4471




4851




4872





4872D

4876






Treatment Type (specific information on treatment
from LTA folders, batch vs. continuous)1'2
Process: Eq, skim, CE, O/W, CPT, sed
Batch vs. Cont: continuous
Additives: H2SO4, ferric chloride, lime, polymer
Targets: unspecified
Flow: unspecified
Process: API, eq, CE, skim
Batch vs. Cont: continuous
Additives: CO2, aluminum chloride
Targets: Oil and grease, metals, organics
Flow: 9,900-12,000 gph during sampling
Process: CE, O/W, oil cooking
Batch vs. Cont: batch
Additives: H2SO4, NaOH, alum, polymer
Targets: Oil and grease
Flow: design max 433,000 gal/batch x 2 batches/day;
during sampling 433,133 gal/batch x 1 batch/day
Same as above

Process: CE, O/W, gravity flot, DAF, oil cooking
Batch vs. Cont: batch
Additives: polymer, alum, NaOH, H2SO4
Targets: Oil and grease, TSS
Flow: 152,000 gpd
Discharger
Type
(indirect/
direct)
Indirect




Indirect




Indirect





Indirect

Indirect




Type of Data (EPA
sampling, industry
sampling episode,
comment data)
EPA sampling




EPA sampling




EPA sampling





Industry-supplied
DMR data
EPA sampling





Influent
Sampling
Point
SP-1




SP-11




SP-4





N/A

SP-4





Effluent
Sampling
Point
SP-5




SP-13




SP-5





SP-5

SP-5





Number of
Effluent
Data Points
4




5




3





4

5




o
oo

-------
                                                                                                10.0 - Limitations and Standards: Data Selection and Calculation
                                                        Table 10-1 (Continued)


Episode
No.
4877






Treatment Type (specific information on treatment
from LTA folders, batch vs. continuous)1'2
Process: Eq, CE, O/W, oil cooking
Batch vs. Cont: batch
Additives: polymer, alum, NaOH, H2SO4, floe
Targets: unspecified
Flow: 100,000-200,000 gpd
Discharger
Type
(indirect/
direct)
Indirect




Type of Data (EPA
sampling, industry
sampling episode,
comment data)
EPA sampling





Influent
Sampling
Point
SP-4





Effluent
Sampling
Point
SP-5





Number of
Effluent
Data Points
5




'Process abbreviations:
                API = API separator
                CE = chemical emulsion breaking
                CPT = chemical precipitation
                DAF = dissolved air flotation
                Eq = flow equalization
                Gravity Hot = gravity flotation
                O/W = oil/water separation
                Sed = sedimentation
                Skim = oil skimmer
treatment units or additives represented by the sampling points are in bold.

-------
                                                       10.0 - Limitations and Standards: Data Selection and Calculation
                                           Table 10-2
                             Unit Operations at Each Episode
Unit
Operation
01
05
07
10
11
12
13
17
18
26
27
28
29
30
32
35
36
39
42
43
44
45
46OR
65
71
72

Description
Abrasive Blasting
Alkaline Cleaning for Oil Removal
Alkaline Treatment Without Cyanide
Aqueous Degreasing
Assembly/Disassembly
Barrel Finishing
Burnishing
Corrosion Preventative Coating
Electrical Discharge Machining
Floor Cleaning
Grinding
Heat Treating
Impact Deformation
Machining
Painting (Spray or Brush)
Polishing
Pressure Deformation
Solvent Degreasing
Testing (Such as Hydrostatic, Dye
Penetrant, Ultrasonic, Magnetic Flux)
Thermal Cutting
Washing of Final Products
Welding
Wet Air Pollution Control of Organic
Constituents
Steam Cleaning
Adhesive Bonding
Calibration
Iron Phosphate Conversion Coating
4471
dry
X


dry


X


X
X

X
X



X


dry




X
4851"
dry
X

X
X




X


dry
X
dry


X
X

X
dry
zero




48727
4872D"

X

dry
dry




X
X
zero
X
X
zero
X




X
dry





4876

X


X




X
X


X




X








4877
X


X
dry




X
X

X
X
zero



X



X




a4851 also performs chromium and nickel electroplating (nonoily operations) where the wastes are contract hauled
and plasma arc machining (a nonoily operation) but never discharged to the water table.
b4872 also has manganese phosphate coating and leaking hydraulic oil from machines.
                                                10-5

-------
                                                10.0 - Limitations and Standards: Data Selection and Calculation

             As a first step, EPA reviewed all of its data from facilities with the Option 6
treatment in the Oily Wastes Subcategory. Table 10-1 identifies all of the episodes with Oily
Wastes Subcategory oil/water separation treatability data in EPA's database.  EPA has data from
six different sampling episodes:  five are EPA sampling episodes (4471, 4851, 4872, 4876, 4877)
and one is industry-supplied DMR data (4872D). For the final rule, EPA based the oil and grease
limitations on the data from Episodes 4872, 4872D, and 4877 and the TSS limitation on the data
from Episode 4851.  The following describes EPA's evaluation of each of the six episodes and
its decisions to include or exclude the data.  As shown in Table 10-2, these episodes encompass a
variety of unit operations included in the Oily Wastes Subcategory.

             Episode 4471 was conducted at a facility that manufactured magnum tractors for
the farming industry.  The facility's primary water-using unit operations included alkaline
cleaning, grinding, heat treating, painting, and testing of the finished product. Episode 4471
operated chemical precipitation and sedimentation following the Option 6 technology.
Consequently, the facility did not need to rely on the Option 6 technology alone to meet any
discharge requirements, and most likely optimized oil and grease and TSS removals following
during the chemical precipitation and solids separation step.  Consequently, its Option 6
technology performance had removal rates of only 31 percent for TSS and 42 percent for oil and
grease during the sampling episode. In contrast, the other facilities had removal rates of over 90
percent for TSS and oil  and grease using the Option 6 technology. In addition, EPA measured oil
and grease using a fireon method, rather than a hexane extractable method used for the other
episodes.  As explained in the NOD A, the sampling data in Phase 1 (this includes Episode 4471)
had been analyzed by EPA Method 413.2, a method utilizing fireon that was unlikely to produce
comparable results to methods approved under 40 CFR 136 (such as EPA Method 413.1). Thus,
EPA did not use these data in determining the final daily maximum oil and grease limitation,
because the facility had not optimized its Option 6 technology (because it did not need to do so)
and the oil and grease data were  not measured by a method comparable to those approved at 40
CFR 136.

             Episode 4851 was conducted at a facility that repaired and manufactured
locomotives.  The facility's primary water-using unit operations included alkaline cleaning,
machining, and testing of the finished product.  Episode 4851 operated the Option 6 technology
and was used as the basis of the final TSS daily maximum limitation because this facility had the
highest concentrations of TSS in the influent (except for Episode 4876, which EPA excluded as
explained below). Episode 4851's average influent TSS concentration was 833  mg/L compared
to the next highest TSS  influent average of 219 mg/L at Episode 4872. Although this facility, on
average, had concentrated TSS influent, it also had the lowest daily value for TSS in the influent
that EPA observed in its sampling of facilities in this Subcategory. Because EPA was concerned
that this value might not represent normal operations for a facility that normally has concentrated
TSS in its influent, it excluded this one value from its calculations of the limitation.  In addition,
EPA excluded all of the oil and grease effluent  data based upon a review of the laboratory
reports. Over the five-day period for the sampling episode, EPA collected 36 oil and grease
samples at the effluent sample point.  One sample (36240) broke and thus was not analyzed. For
31 other samples (36232-36239, 36241-36263), when EPA performed  a final review of the
                                          10-6

-------
                                                10.0 - Limitations and Standards: Data Selection and Calculation

laboratory reports, it realized that the ongoing precision recoveries (OPR) were below the
acceptable range of 79-144 percent that is specified in Method 1664. For the four remaining
samples (36264-36267), EPA considered these values to be 'minimum values' because the
matrix spike and its matrix sample duplicate (MS/MSD) recoveries were outside of the criteria in
the method.  For these reasons, EPA excluded the oil and grease data from Episode 4851.

              Episodes 4872 and 4872D are from a facility that manufactured automotive parts,
including axles, shafts, tubes, housings, and transmission gear sets.  The facility's unit operations
included machining, polishing, impact deformation (punch pressing), heat treatment (carburizing
and tempering), and washing of the components. The facility also performed manganese
phosphate coating and painting operations.  In general, based on information obtained from
episode 4872, the facility generated approximately 70 percent of the daily process wastewater
from 21 aqueous parts washers, and approximately 30 percent from 14 machining operations
containing a 5-percent solution of machining coolant. Less than 1 percent of the wastewater flow
was generated from minor water-producing operations, including the paint booth water curtain,
the manganese phosphate coating operation, heat treatment, and leaking hydraulic oil from
machines (tramp oil).  Because this facility also commingles wastewater generated by CFR 433
operations (i.e., manganese phosphate coating) with wastewater generated by oily waste
operations, it would be subject to 433  rather than 4382. However, EPA determined it was
appropriate to retain this facility in its Part 438 limitations calculations because the commingled
wastewater from this facility largely comprises wastewater generated from oily waste operations
(>99 percent).  Furthermore, EPA compared the influent concentrations of the regulated
parameters at this facility with those at other oily waste facilities and found them to be
comparable.

              During the time periods of these episodes, this facility operated the Option 6
technology to treat its wastewater. As noted in Section 10.1, EPA has treated  its self-monitoring
data separately from the EPA sampling data. The data for the two episodes were collected about
two years apart (1997 for the sampling episode and 1999 for the self-monitoring episode). EPA
expects that some changes in process, production mix, volume of production,  and wastewater
treatment systems were likely to have occurred during the two-year period and has used the data
as if they were from two different facilities.  EPA also notes that the ranges of the daily oil and
grease effluent concentrations were different for the two episodes, with Episode 4872 ranging
from 44.8 to 57.1 mg/L and Episode 4872D ranging from 8.6 to 23.6 mg/L.

              For Episode 4872, the treatment system consisted of a large batch tank in which
the facility added emulsion breaking chemicals and then allowed the oil to separate from the
water. The facility then discharged the water layer (i.e., the lower layer). Upon review of the
operating procedures for this facility, EPA determined that the approach used to determine when
to stop the draw-down was based solely on tank level, as opposed to being based on any type of
measurement.  While EPA has concerns about this approach and has incorporated costs  in this
rule for an upgrade to remove the subjectivity, EPA determined that the Episode 4872D data
2See 438.2(b)

                                          10-7

-------
                                                 10.0 - Limitations and Standards: Data Selection and Calculation

demonstrated that the system can achieve low concentrations of oil and grease when the
treatment system is operated properly.  For this reason, EPA has included all but one oil and
grease value in calculating the limitation.  EPA excluded the concentration value of 25.8 mg/L
from the third grab sample (38970) on Day 1 of Episode 4872, because the MS/MSD percent
recoveries were below the method criteria and the value is considered to be a minimum value.
Because its field duplicate value was reported with a higher value of 65.9 mg/L and met the
criteria in the data review guidelines, the field duplicate value was used in calculating the oil and
grease limitation instead (i.e., sample 38970 was excluded). EPA also considered excluding the
data value for the fourth grab sample (38971) on Day 1, because the MS percent recovery was
below the method criteria and the relative percent difference (RPD) between the MS and its MSD
also exceeded the method criteria. Despite these qualifiers, EPA decided to retain this sample
because it was consistent with the value for its field duplicate (105  mg/L) which had met the
method criteria.

              Episode 4876 was conducted at a facility that manufactured engines for
automobiles and light trucks. The primary wastewater generating operations at this facility
included machining and grinding operations, which require a water-based cutting fluid.  The
facility also performed alkaline cleaning operations.  Episode 4876 treated  its wastewater using a
DAF system following the Option 6 technology.  When EPA reviewed these data in detail, it
found that the facility appeared to be optimizing its Option 6 portion of the treatment technology
for TSS removals, but not oil and grease.  Because the system was not optimized for oil  and
grease removals (because the facility additionally used the DAF system for this purpose), EPA
excluded those data in calculating the oil and grease limitation.  Although the facility had a
removal rate of 99 percent for TSS, EPA excluded the TSS effluent data values because EPA had
collected daily grab  samples at this sample point, rather than daily composite samples that EPA
expects that facilities would use in complying with the final TSS daily maximum limitation3. As
explained in Section 10.5, while it had excluded the data from its limitation calculations, EPA
ultimately used these TSS data to evaluate the limitation.

              Episode 4877 was conducted at a facility that manufactured and assembled
automatic transmissions and chassis components. Manufacturing processes included machining,
grinding, impact deformation, abrasive blasting,  and aqueous degreasing of the metal
components.  The facility also performed painting operations; however, no wastewater was
generated from painting.  In general, the facility generated approximately 75 percent of its
process wastewater from 60 aqueous parts washers and 20 percent from 18 machine coolant
recirculation filtration systems (hydromation pits), containing a 4- to 12-percent solution of
coolant used for machining and grinding operations.  Miscellaneous wastewater sources such as
floor washing, leaking hydraulic oil, and transmission oil from hydrostatic testing were included
in the remaining 5 percent of the flow. This facility treated its wastewater using the Option 6
technology.  In calculating the limitation, EPA excluded the oil and grease  data from the second
day because operation on that day was not representative of the normal operating conditions for
3 This system was a batch system that discharged over the course of 24 hours. EPA expects that facilities with this
type of system would conduct continuous compliance monitoring.

                                           10-8

-------
                                                 10.0 - Limitations and Standards: Data Selection and Calculation

Option 6 technology. As documented in the sampling episode report, on that day only, the
operator failed to add the proper treatment chemicals. EPA also reviewed the laboratory reports
and identified qualifiers on two of the effluent samples used to calculate the oil and grease
limitation, but has included both results in calculating the oil and grease limitation. These
samples were the third and fourth grab samples (39564 and 39565) collected on Day  1 of the
sampling episode. For both samples, the RPD between the MS and its MSD exceeded the
method criteria.  In addition, the MSD recovery was below the method criteria for the fourth grab
sample. In conjunction with those samples, EPA had collected field duplicates.  The oil and
grease limitation was calculated using daily values calculated from the average of each duplicate
pair. When EPA calculated the daily value with the averages of each duplicate pair (see Section
10.3), it found virtually no difference if the qualified data were included or excluded. Because
their inclusion results in a minutely higher daily value for Day 1, the values for samples 39564
and 39565 were included in calculating the limitations.

10.3         Data Aggregation

             In developing the limitations, EPA modeled daily data values rather than
individual sample measurements. EPA's approach of aggregating multiple analytical results to
obtain a single daily value is consistent with standard, conventional practice in environmental
analytical work.  This approach also gives one day's sampling information appropriate weight in
determining effluent limitations and is consistent with requirements of NPDES regulations at 40
CFR 122 which define the daily discharge.

             In some  cases, EPA mathematically aggregated two or more samples to obtain a
single value that could be used in other calculations.  This occurred with field duplicates and grab
samples collected over time to represent a single waste stream. Table 10-3 lists these values.
Table 10-4 lists the influent and effluent data after these aggregations were completed and a
single daily value was obtained for each day for each pollutant.

             In all aggregation procedures, EPA considered the censoring type associated with
the data. EPA considered measured values to be detected. In statistical terms, the censoring type
for such data was 'noncensored' (NC).  The Agency censored measurements reported as being
less than some sample-specific detection limit (e.g., <10 mg/L) and considered them  to be
nondetected (ND). In the tables and data listings in this document and the rulemaking record,
EPA uses the abbreviations NC and ND to indicate the censoring types.  The data used as a basis
for the final limitations are all NC and thus all aggregated results also are considered to be NC.

             This subsection describes each of the different aggregation procedures. They are
presented in the order that the aggregation was performed (i.e., field duplicates were  aggregated
first and grab samples second). Table 10-3 lists the effluent data before aggregation and Table
10-4 lists the daily influent and effluent values after any aggregation.
                                           10-9

-------
                                                    10.0 - Limitations and Standards: Data Selection and Calculation
                                         Table 10-3
                           Effluent Data Before Aggregation3
Pollutant
Oil and
Grease




















TSS
Episode
4872








4877












4851
Sample
Day
1


2



3



1



3



4



5



1
2
3
Original Sample
Concentration (mg/L)
23.1
14.4

108.0
89.6
54.5
21.1
14.1
33.2
63.1
68.2
57.9
25.0
21.0
33.0
20.0
12.0
16.0
10.0
21.0
21.0
11.0
24.0
29.0
13.0
31.0
8.0
8.0
54.0
40.0
36.0
Corresponding Field
Duplicate (if any)
Concentration (mg/L)
50.8
23.3
65.9
105.0








26.0
15.0
20.0
32.0












26.0
30.0
62.0
This table includes only values that were later aggregated with other values. See Table 10-4 for all daily values.
                                             10-10

-------
                                                10.0 - Limitations and Standards: Data Selection and Calculation
                                      Table 10-4
                    Data After Aggregation (i.e., Daily Values)
Pollutant
Oil and Grease








TSS



Episode
4872


4872D



4877



4851



Sample
Day
1
2
3
1
2
o
5
4
1
3
4
5
1
2
o
5
4
Influent
Daily Value (mg/L)
696
2182
502




557
997
544
469
1720
508
373
615
Effluent
Daily Value (mg/L)
57.050
44.825
55.600
12.100
23.600
15.200
8.640
24.000
14.750
21.250
15.000
40.000
35.000
49.000
48.000
10.3.1
Aggregation of Field Duplicates
             During its sampling episodes, EPA collected field duplicates for quality control
purposes.  Generally, 10 percent of the number of samples collected were duplicated. Field
duplicates are two samples collected for the same sampling point at the same time, assigned
different sample numbers, and flagged as duplicates for a single sample point at a facility.
Because the analytical data from each duplicate pair characterize the same conditions at that time
at a single sampling point, EPA averaged the data to obtain one value for each duplicate pair.
This aggregation step for the duplicate pairs was the first step in the aggregation procedures.
10.3.2
Aggregation of Grab Samples
             During its sampling episodes, EPA collected two types of samples: grab and
composite. For oil and grease, EPA collected four grab samples over the course of each day of
sampling during each sampling episode. To obtain one value characterizing the oil and grease
levels at the sample point on a single day, EPA arithmetically averaged the measurements to
obtain a single value for the day. In developing the TSS limitation, EPA used the concentration
values of daily composite samples from episode 4851,  and thus, this aggregation step was not
necessary.
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                                                 10.0 - Limitations and Standards: Data Selection and Calculation

10.4          Overview of Limitations

              The preceding subsections discuss the data selected as the basis for the limitations
and the data aggregation procedures EPA used to obtain daily values in its calculations. This
subsection provides a general overview of limitations.

              The oil and grease and TSS limitations are provided as maximum daily discharge
limitations.  The definition provided in 40 CFR 122.2 states that the "maximum daily discharge
limitation" is the "highest allowable daily discharge." Daily discharge is defined as the
"discharge of a pollutant measured during a calendar day or any 24-hour period that reasonably
represents the calendar day for purposes of sampling."

              EPA did not establish monthly average limitations for oil and grease and TSS
because a monthly average limitation would be based on the assumption that a facility would be
required to monitor more frequently than once a month. For the rule, EPA has determined that
one monthly monitoring event is sufficient; however, if permitting authorities choose to require
more frequent monitoring for oil and grease and TSS, they may set monthly average limitations
and standards based on their best professional judgement.  (See, e.g., 40 CFR 430.24(a)(l),
footnote b.)

              The following three subsections describe EPA's objective for daily maximum
limitations, the selection of the percentile for those limitations, and compliance with final
limitations.  EPA has included this discussion in Section 10.0 because these fundamental
concepts are often the subject of comments on EPA's effluent guidelines regulations and in
EPA's contacts and correspondence with industry.

10.4.1         Objective

              In establishing daily maximum limitations, EPA's objective is to restrict the
discharges on a daily basis to a level that is achievable for a facility that targets its treatment at
the long-term average.  EPA acknowledges that variability around the long-term average results
from normal operations. This variability means that occasionally facilities  may discharge at a
level that is lower than or greater than the long-term average.  To allow for possibly higher daily
discharges, EPA has established the daily maximum limitation. A facility that discharges
consistently  at a level near the daily maximum limitation would not be operating its treatment
system to achieve the long-term average, which is part of EPA's objective in establishing the
daily maximum limitations.  That is, targeting treatment to achieve the limitations may result in
frequent values exceeding the limitations  due to routine variability in treated effluent.

              In estimating the limitations, EPA first determines an average performance level
(the "option long-term average" discussed in Section 10.5) that a facility with well-designed and
operated model technologies (that reflect the appropriate level of control) is capable of achieving.
This long-term average is calculated from the  data from the facilities using the model
technologies for the option. EPA expects that all facilities subject to the final limitations will
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                                                  10.0 - Limitations and Standards: Data Selection and Calculation

design and operate their treatment systems to achieve the long-term average performance level on
a consistent basis because facilities with well-designed and operated model technologies have
demonstrated that this can be done.

              Next, EPA determines an allowance for the variation in pollutant concentrations
when wastewater is processed through extensive and well-designed treatment systems. This
allowance incorporates all components of variability, including shipping, sampling, storage, and
analytical variability. This allowance is incorporated into the limitations through the use of the
variability factors that EPA calculated from the data from the facilities using the model
technologies. If a facility operates its treatment system to achieve the relevant option long-term
average, EPA expects the facility will be able to comply with the limitations. Variability factors
assure that normal fluctuations in a facility's treatment are accounted for in the limitations. By
accounting for these reasonable excursions above the long-term average, EPA's use of variability
factors results in limitations that are generally well above the actual long-term averages.

              EPA calculates the percentile used  as a basis for the daily maximum limitation
using the product of the long-term average and the daily variability factor. The following
subsection describes EPA's rationale for selecting the 99th percentile as the basis for the daily
maximum limitations.

10.4.2        Selection of Percentiles

              EPA calculates limitations based upon percentiles chosen, on one hand, to be high
enough to accommodate reasonably anticipated variability within control of the facility and, on
the other hand, to be low enough to reflect a level  of performance consistent with the Clean
Water Act requirement that these effluent limitations be based on the "best" technologies.  The
daily maximum limitation is an estimate of the 99th percentile of the distribution of the daily
measurements.

              The 99th percentile does not relate  to, or specify, the percentage of time a
discharger operating the "best available" or "best available demonstrated" level of technology
will meet (or not meet) the limitations.  Rather, EPA used this percentile in developing the daily
maximum limitation. If a facility is designed and operated to achieve the long-term averages on
a consistent basis and the facility maintains adequate control of its processes and treatment
systems, the allowance for variability provided in the daily maximum limitations is sufficient for
the facility to meet the requirements of the rule. EPA used 99 percent to draw a line at a definite
point in the statistical distributions (100 percent is not feasible because it represents an infinitely
large value), while setting the percentile at a level  that would ensure that operators work hard to
establish and maintain the appropriate level of control. By targeting its treatment at the long-
term average, a well-operated facility should be able to comply with the limitations at all times
because EPA has incorporated an appropriate allowance for variability into the limitations.

              In conjunction with the statistical methods,  EPA performs an engineering review
to verify that the limitations are reasonable based upon the design and expected operation of the
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                                                 10.0 - Limitations and Standards: Data Selection and Calculation

control technologies and the facility process conditions. As part of that review, EPA examines
the range of performance by the facility datasets used to calculate the limitations.  Some facility
datasets demonstrate the best available technology.  Other facility datasets may demonstrate the
same technology, but not the best demonstrated design and operating conditions for that
technology.  For these facilities, EPA will evaluate the degree to which the facility can upgrade
its design, operating, and maintenance conditions to meet the limitations.  If such upgrades are
not possible, then EPA will modify the limitations to reflect the lowest levels that the
technologies can reasonably be expected to achieve.

10.4.3         Compliance with Limitations

              EPA promulgates limitations with which facilities can comply at all times by
properly operating and maintaining their processes and treatment technologies. EPA uses a
percentile of a statistical distribution in developing the daily maximum limitation because
statistical methods provide a logical and consistent framework for analyzing a set of effluent data
and determining values from the data that form a reasonable basis for effluent limitations. EPA
establishes the limitations on the basis of percentiles estimated using data from facilities with
well-operated and controlled processes and treatment systems. However, because EPA uses a
percentile basis, the issue of exceedances (i.e., values that exceed the limitations) or excursions is
often raised in public comments on limitations. For example, comments often suggest that EPA
include a provision that allows a facility to be considered in compliance with permit limitations if
its discharge exceeds the  daily maximum limitations one day out of 100.  This issue was, in fact,
raised in other rules, including EPA's final Organic Chemicals, Plastics, and Synthetic Fibers
(OCPSF) rulemaking.   EPA's general approach there for developing limitations based on
percentiles is the same in this rule, and was upheld in Chemical Manufacturers Association v.
U.S. Environmental Protection Agency. 870 F.2d 177, 230 (5th Cir. 1989). The Court
determined that:

              EPA reasonably concluded that the data points exceeding the 99th
              and 95th percentiles represent either quality-control problems or
              upsets because there can be no other explanation for these isolated
              and extremely high discharges. If these data points result from
              quality-control problems, the exceedances they represent are within
              the control of the plant. If, however, the data points represent
              exceedances beyond the control of the industry, the upset defense
              is available.
              Id at 230.

              As that Court recognized, EPA's allowance for reasonably anticipated variability
in its effluent limitations, coupled with the availability of the upset defense, reasonably
accommodates acceptable excursions. Any further excursion allowances would go beyond the
reasonable accommodation of variability and would jeopardize the effective control of pollutant
discharges on a consistent basis and/or bog down administrative and enforcement proceedings in
detailed fact-finding exercises, contrary to Congressional intent. See, as an example,  Rep. No.
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                                                10.0 - Limitations and Standards: Data Selection and Calculation

92-414, 92d Congress, 2d Sess. 64, reprinted in A Legislative History of the Water Pollution
Control Act Amendments of 1972 at 1482; Legislative History of the Clean Water Act of 1977 at
464-65.

              EPA expects that facilities will comply with promulgated limitations at all times.
If an exceedance is caused by an upset condition, the facility would have an affirmative defense
to an enforcement action if the requirements of 40 CFR 122.41(n) are met. If the exceedance is
caused by a design or operational deficiency, then EPA has determined that the facility's
performance does not represent the appropriate level of control. For promulgated limitations  and
standards, EPA has determined that such exceedances can be controlled by diligent process and
wastewater treatment system operational practices such as frequent inspection and repair of
equipment, use of back-up systems, and operator training and performance evaluations.

              EPA recognizes that, as a result of the rule, some dischargers may need to
improve treatment systems, process controls, and/or treatment system operations in order to
consistently meet the effluent limitations.  EPA believes that this consequence is consistent with
the Clean Water Act statutory framework,  which requires that discharge limitations reflect the
best technology.
10.5
Calculation of the Limitations
              This section discusses the calculation of the daily maximum limitations for TSS
and oil and grease.

              First, EPA calculated the episode long-term average and daily variability factor by
using the modified delta-lognormal distribution (see Appendix E). Table 10-5 lists these
episode-specific values.

                                      Table 10-5
          Episode Long-Term Averages and Daily Variability Factors
Pollutant
Oil and grease
TSS
Episode
4872
4872D
4877
4851
Episode Long-Term Average
(mg/L)
52.6533
15.2101
18.8921
43.1442
Episode Daily Variability
Factor
1.3489
2.4403
1.7203
1.4312
              Second, EPA calculated the option long-term average for a pollutant as the
median of the episode-specific long-term averages for that pollutant. The median is the midpoint
of the values ordered (i.e., ranked) from smallest to largest. For oil and grease, when the three
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                                                 10.0 - Limitations and Standards: Data Selection and Calculation

episode long-term averages are ordered, this midpoint value is 18.89 mg/L from Episode 4877.
For TSS, this midpoint value is the same as the episode long-term average from Episode 4851.

              Third, EPA selected the option daily variability factor.  For oil and grease, EPA
used the self-monitoring data, Episode 4872D, as the basis of the option daily variability factor.
In the proposal and NOD A, when EPA used multiple episodes as the basis of a limitation, it used
the mean of the episode daily variability factors. That practice was consistent with EPA's
development of limitations for other industries. However, for this pollutant in this subcategory,
EPA has determined that it is appropriate to deviate from its normal practice, because each of the
self-monitoring measurements were obtained several months apart (i.e., 2/23/99, 4/29/99,
8/11/99, and 10/28/99). As explained in the NOD A, EPA intended to investigate whether
autocorrelation was likely to be present in the  data.  When data are positively autocorrelated, it
means that measurements taken at specific time intervals (such as 1  day or 2 days apart) are
related.  To determine autocorrelation in the data, many measurements for each pollutant would
be required with values for every single day over an extended period of time. Despite its requests
to industry, the data were not made available to EPA for Option 6 oily wastes effluent. However,
by selecting the self-monitoring data, each measured several months apart, as the basis of the
option daily variability factor, EPA has avoided the possibility of autocorrelation existing in the
data used as a basis  of the option daily variability factor for oil and grease. For TSS, the option
daily variability factor is the same as the episode daily variability factor from Episode 4851,
because EPA used the data from that facility as the basis for the limitation as explained in
Section 10.2. While autocorrelation might exist in the Episode 4851 data, EPA selected a facility
with high concentrations of TSS in the influent as the basis of the option daily variability factor.
EPA notes that no facilities with the Option 6  technology with similar high concentrations of
TSS influents provided any daily measurements of TSS effluent concentrations. From the
information that EPA had available to it, EPA determined that the allowance for variability
provided by the Episode 4851 data was sufficient and the limitation  was demonstrated to be
achievable, as described later in this subsection.

              Fourth, EPA calculated each daily maximum limitation for a pollutant using the
product of the option long-term average and the option daily variability factor.  EPA rounded the
limitation to two significant digits.  The rounding procedure rounds  up values of five and above,
and rounds down values of four and below. Table 10-6 provides the option long-term average,
option daily variability factor, and the daily maximum limitation.

10.6          Evaluation of the Limitations

              To evaluate the limitations, EPA compared the daily  maximum limitations to all
of the effluent data that it had received from facilities in the Oily Wastes Subcategory.  In
addition, EPA compared the values of the final daily maximum limitation to the values presented
in the 2001 proposal and the 2002 NODA. The following subsections describe these evaluations.
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                                                 10.0 - Limitations and Standards: Data Selection and Calculation
                                      Table 10-6

   Option Long-Term Averages, Daily Variability Factors, and Limitations
Pollutant
Oil and grease
TSS
Option Long-Term Average
(mg/L)
19
43
Option Daily Variability
Factor
2.4
1.4
Daily Maximum
Limitation (mg/L)
46
62
10.6.1        Comparison to Data

              This section compares the daily maximum limitations to all of the data that EPA
had available to it from the Oily Wastes Subcategory. In the following subsections, EPA first
evaluated the TSS limitation and then the oil and grease limitation. In addition, EPA compared
the data from each facility to both limitations,  because it had received many comments stating
that facilities would have difficulty complying with multiple limitations simultaneously.  From
its conclusions about the data comparisons, EPA has determined that the data do not support
such assertions. As a result of the data comparisons and reviews described below, EPA has
concluded that facilities that properly design and operate to achieve the option long-term  average
will be able to comply with the limitations.

Total Suspended Solids Limitation

              For TSS, none of the daily values from Episode 4851 (i.e, the basis of the
limitation) were greater than the daily maximum limitation of 62 mg/L. EPA performed this
comparison to determine whether it used appropriate distributional assumptions for the data used
to develop the limitations (i.e., whether the curves EPA used provide a reasonable "fit" to the
actual effluent data4 or if there was an engineering or process reason for an unusual discharge).
As a result of this comparison, EPA determined that the distributional  assumptions appear to be
appropriate for these data. As a further evaluation of these limitations, EPA compared the
individual measurements  from field duplicate  pairs and  also found that none of the individual
values were greater than the limitation.

              EPA performed additional comparisons of the limitation to other EPA sampling
data obtained from the Option 6 technology in the Oily Wastes Subcategory, although they were
not used as a basis of the limitation. EPA compared the limitation to the TSS data values from
Episode 4876 (see Section 10.2 for EPA's reasons for excluding these data from its limitation
4EPA believes that the fact that the Agency performs such an analysis before promulgating limitations might give the
impression that EPA expects occasional exceedances of the limitations. This conclusion is incorrect. EPA
promulgates limitations that facilities are capable of complying with at all times by properly operating and
maintaining their treatment technologies.

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                                                10.0 - Limitations and Standards: Data Selection and Calculation

calculations). Although this episode had more concentrated TSS influent than Episode 4851
(which was the basis for the limitation), all of its TSS effluent data values were considerably less
than the daily maximum limitation. In addition, none of the individual measurements exceeded
the option long-term average of 43 mg/L.  For the episodes that EPA excluded from the
limitations calculations because they had less concentrated influents (Episodes 4872,  4872D, and
4877), all of the daily values and individual values in each field duplicate pair were below the
option long-term average, except for the data from the second sampling day during Episode 4877
when the facility did not add the proper treatment chemicals. During Episode 4471, the facility
achieved levels lower than the limitation on three sampling days even though the facility had not
optimized its treatment system. EPA notes that the single effluent value greater than  the
limitation was also greater than its corresponding influent value, and thus, the system did not
demonstrate any removals of TSS on that day. (See DCNs 36000S and 36034 in Section 19.1 of
the record and DCN 00573 in Section 5.2.32.1.)

             EPA also compared the TSS limitation to the sampling episode and self-
monitoring data obtained from three facilities (4819, 4820, and 4824) that treated oily wastes
using ultrafiltration systems. The average influent concentrations at these facilities ranged from
128 mg/L to 10,100 mg/L. During the sampling episodes and their own self-monitoring, none of
the facilities had average concentration values that were greater than 12 mg/L, which  is
substantially less than the option long-term average of 43 mg/L used in calculating the limitation.
Furthermore, during EPA's sampling episodes, none of the effluent data values were  greater than
17 mg/L.

             EPA compared the TSS limitation to the data from Episode 7052P that operated
DAF technology in addition to the Option 6 technology. The influent values ranged from 212 to
4440 mg/L.  This facility demonstrated treatment performance levels below the option long-term
average for each of the four days that the facility sampled.

             As a further evaluation of its TSS daily maximum limitation, EPA examined TSS
monitoring data provided by the questionnaire respondents that operated facilities in the Oily
Wastes Subcategory, including two facilities that operated the Option 6 technology. Each facility
provided the average of its TSS concentrations for one year, but not the individual measurements
or the influent concentrations (because the questionnaire did not request this information).  For
both Option 6 facilities, the average TSS concentrations were below the daily maximum
limitation as well as the long-term average. Other than these two facilities, the questionnaire
respondents in the Oily Wastes Subcategory either reported that they used a different  technology
than Option 6 or did not provide TSS average concentrations.  Except for two facilities, the
reported TSS long-term averages were all less than the option long-term average.  One of the two
exceptions used a treatment technology that was less sophisticated than Option 6, and thus, it is
to be expected that it would have a higher TSS average concentration than demonstrated by
Option 6.  The other exception operated a carbon adsorption and oil/water separation  treatment
system.  Operated properly, this treatment technology is equivalent or better than the  Option 6
technology.  EPA did not receive sufficient information in the survey from this facility to conduct
a detailed engineering analysis of their unit operations and treatment system.  Using the limited
information that it had, EPA compared this facility's unit operations and wastewater generating

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                                                 10.0 - Limitations and Standards: Data Selection and Calculation

operations to similar facilities in this subcategory, and found no factors that would prevent this
facility from achieving the demonstrated TSS removal of Option 6. Furthermore, this facility did
not provide comments to EPA stating that it would be unable to meet the TSS limitations in the
proposed rule or the NODA. EPA considers that it may be possible that the carbon adsorption
system was overloaded on one or more occasions resulting in large TSS discharges that affected
the overall average TSS value reported by the facility.  To ensure that the facility would be
capable of complying with the limitation, EPA assigned a one-time unit upgrade cost to this
facility which includes contractor fees,  operator training, and additional treatment controls.  With
this cost for additional system optimization, the site should be able to comply with the daily
maximum limitation.

Oil and Grease Limitation

              For oil and grease, EPA compared the daily maximum limitations to the data from
Episodes 4872, 4872D, and 4877 which were used as the basis of the limitation. None of the
daily values or even the individual values for grab samples from Episodes 4872D and 4877 were
greater than the daily maximum limitation of 46 mg/L. For Episode 4872, EPA found some daily
values (and values for individual grab samples) that were greater than the daily  maximum
limitation. While EPA recognizes that the data from this episode forms the technology basis of
the oil and grease limitation, based upon its review of the data, EPA concluded  that
improvements to its system would optimize its treatment performance. Based upon this review,
EPA also discussed the possibility of excluding these data from developing the  daily maximum
limitation because the data probably reflect less than optimal performance.5 EPA decided to
maintain a conservative approach by retaining these data in developing the limitation.6 As a
result of this comparison, EPA determined that the distributional assumptions appear to be
appropriate for effluent data from the Option 6 technology.

              EPA performed additional comparisons of the limitation to other EPA sampling
data obtained from the Option 6 technology in the Oily Wastes Subcategory, although the data
were not used as a basis of the limitation. During Episode 4876, the system still achieved levels
lower than the daily maximum limitation on two of the sampling days although it was not
optimized for oil and grease removals.  Although EPA used most of the data from Episode 4877
in calculating the limitation, it had excluded the data for the second sampling day as explained in
Section 10.2. This daily value was greater than the limitation, which is what EPA expects from a
system operating without the proper treatment chemicals.  EPA did not compare the Episode
4177 and 4851 data values to the limitation because any conclusions would have been hard to
5 A review of the treatment technology as this facility demonstrates that this facility lacks some parts of the Option 6
technology basis (i.e., skimmer).

""Because EPA did not include this facility in its sample for the questionnaire, it did not include costs for it in the rule.
Also, as explained in Sections 11.0 and 12.0, EPA only estimated compliance costs and loadings reductions for
facilities in its cost and loads model database. Had this been a costed facility, EPA would have included cost
estimates for additional energy, labor and equipment for this facility to improve the operation of its current systems
in order to comply with the daily maximum limitation.

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                                                 10.0 - Limitations and Standards: Data Selection and Calculation

interpret. As explained in Section 10.2, the data for Episode 4177 and 4851 were excluded due
to concerns about the analytical method and the quality of the data. (See DCNs 36000S and
36034 in Section 19.1 of the record and DCN 00573 in Section 5.2.32.1.)

              EPA also compared the oil and grease limitation to the sampling episode and self-
monitoring data obtained from the three ultrafiltration facilities.  Two facilities (4819 and 4820)
had average effluent values that were less than the option long-term average of 19 mg/L used in
calculating the limitation, and their daily effluent values during EPA's sampling episodes were
all below the daily maximum limitation.  These episodes had influent values ranging from  90 to
144 for Episode 4820 and 689 to 857 for Episode 4819.  For the third facility (4824), EPA's
sampling data had an average effluent value below the daily maximum limitation, although one
daily value at 78 mg/L was greater than the limitation. During the sampling episode, the
facility's oil and grease influent values ranged from  660 to 3670 mg/L.  The self-monitoring data
(4824D) for that facility had an average value of 47 mg/L, which is greater than the limitation.
However, this facility demonstrated poor performance of the ultrafiltration system during EPA's
sampling episode. It was only able to remove about half of the 5-day biochemical oxygen
demand (BOD5) and chemical oxygen demand (COD) concentrations, resulting in effluent
averages of 1390 mg/L and 5450 mg/L, respectively. Thus, because this facility did not achieve
typical removal rates for pollutants generally well treated by ultrafiltration, EPA has determined
that its concentrations of oil and grease are abnormally high and can be corrected by improved
operations.

              EPA compared the  oil and grease limitation to the data from the DAF facility
(Episode 7052P).  The effluent average concentration was below the option long-term average,
with each daily concentration having a value less than the daily maximum limitation. The
influent levels ranged from 212 to 1020 mg/L.

              As it had for TSS, EPA examined oil and grease monitoring data provided by the
questionnaire respondents that operated facilities in the Oily Wastes Subcategory, including three
facilities that operated the Option 6 technology. For two of the three Option 6 facilities, the
average oil and grease concentrations were below the daily maximum limitation as well as the
long-term average. For the third, the average oil and grease concentration was slightly above the
long-term average (21 as compared to 19 mg/L), but well below the daily maximum limitation.
In the questionnaire, the facility reported that it used Method 413.1 to measure oil and grease.
Because EPA used only data measured by Method 1664 in developing the TSS limitation, the
slight difference between the averages might be a result of the different solvents used in the two
analytical methods or just normal variability that has been incorporated into the option daily
variability factor.  For the nonoption 6  facilities, the reported oil and grease long-term averages
were all less than the option long-term average, except for the one facility that operated a less
sophisticated treatment technology, resulting in a higher oil and grease average concentration
value. In developing the rule, EPA also included costs for this facility to upgrade its treatment
system to comply with the daily maximum limitation.
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                                                 10.0 - Limitations and Standards: Data Selection and Calculation

Both Limitations

              To respond to comments that stated that facilities would have difficulties
complying with multiple limitations simultaneously, EPA compared the data from each facility to
both limitations.

              For facilities with the Option 6 technology for which EPA had daily data values
for both TSS and oil and grease concentrations, only Episode 4872 had any daily values that were
greater than the oil and grease daily limitation and none were greater than the TSS limitation.
Thus, Episode 4872 was still able to treat its TSS and sometimes its oil and grease influent
concentrations to low levels in the effluent, although, as explained above, it has not optimized its
treatment system.

              For facilities with the ultrafiltration technology, two had average effluent values
that were below both limitations. Although the third facility had poor removals of key
parameters including oil and grease, it still had adequate TSS removals and the average effluent
values were less than the TSS limitation.

              The facility with the DAF technology had daily concentration values below both
limitations for each sampling day.

              For the seven facilities that provided averages of their monitoring data in the
questionnaire,  only two reported effluent averages above either limitation. One facility operates
a technology that is less sophisticated than Option 6, and thus,  it is not surprising that its effluent
is more concentrated than Option 6 levels.  The other facility reports that it operates the Option 6
technology, but, while it was able to treat oil and grease to levels below detection, it had an
average value greater than the TSS limitation. As explained above, EPA has incorporated costs
into the rule for this facility to improve its operations.

10.6.2        Comparison to Proposed and NODA Values

              EPA compared the  TSS and oil and grease daily maximum limitations to the
values in the 2001 proposed rule and the 2002 NODA.  Table 10-7 shows the three sets of values.
In the NODA,  EPA requested comment on an approach that would select the higher value of the
proposed and revised limitation. In general, the comments that EPA received did not address this
approach, but rather focused on the data selection and achievability of the limitations. Thus,
EPA has chosen to base the final limitations on its in-depth review of the episodes, as explained
in Sections 10.1 and 10.2.  As a result of these changes, the final oil and grease daily maximum
limitation has a value that is greater than the proposed and NODA values; and the TSS daily
maximum limitation has a value that is slightly less than the proposed and NODA values. EPA
has determined that these are reasonable outcomes of its in-depth review of the data.
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                                     10.0 - Limitations and Standards: Data Selection and Calculation
                           Table 10-7
Daily Maximum Limitations: Proposal, NOD A, and Final Rule
Pollutant
Oil and grease (mg/L)
TSS (mg/L)
2001 Proposal
27
63
2002 NODA
45.9
63.0
Final Rule
46
62
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                                                         11.0 - Costs of Technology Bases for Regulations

11.0         COSTS OF TECHNOLOGY BASES FOR REGULATIONS

             This section presents EPA's estimates of costs for the MP&M industry to comply
with the technology options considered and described in Section 9.0. EPA estimated the
compliance costs for each technology option in order to determine potential economic impacts on
the industry. EPA also weighed these costs against the effluent reduction benefits resulting from
each technology option. This section includes cost estimates for options and subcategorization
schemes that EPA selected for promulgation and for those that EPA ultimately rejected. Section
12.0 presents Agency estimates of corresponding annual pollutant loadings and removals.  The
Agency is reporting estimates of potential economic impacts associated with the total estimated
annualized costs of the regulation separately,  in the Economic, Environmental and Benefit
Analysis of the Final Metal Products & Machinery Rule (EEBA).

             Section 11.1 summarizes the costs associated with each stage of the regulation
development process.  The remainder of this section discusses the following information:

             •       Section 11.2: Selection and development of cost model inputs;

             •       Section 11.3: The methodology for estimating costs, including an
                     overview of the cost model;

             •       Section 11.4: The specific methodology and assumptions used to estimate
                     costs for the Notice of Data Availability (NOD A) and for analyses after
                    the NOD A;

             •       Section 11.5: Design and cost elements for pollution prevention and end-
                     of-pipe technologies;

             •       Section 11.6: Examples of how sites were allocated costs, from start to
                    finish; and

             •       Section 11.7: References used in this section.

             Tables are presented in the text and figures are located at the end of this section.

11.1         Summary of Costs

             This subsection summarizes EPA's final capital, operating and maintenance
(O&M), and annualized cost estimates for each final regulatory option. Table 11-1 summarizes
the capital and O&M costs and Table 11-2 summarizes the annualized costs. These tables also
present costs for each
                                          11-1

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                                                 11.0 - Costs of Technology Bases for Regulations
              Table 11-1
Incremental Capital and O&M Costs
Subcategory
General Metals
Metal Finishing
Job Shops
Non-Chromium
Anodizing
Printed Wiring
Board
Steel Forming
and Finishing
Oily Wastes
Discharge
Status
Direct
Indirect
Direct
Indirect
Direct
Indirect
Direct
Indirect
Direct
Indirect
Direct
Indirect
Options
Evaluated Since
Proposal
Option 2
Option 2, 1MGY
cutoff
Upgrade Option
50% Local Limits
Option 2
Option 2
Upgrade Option
Option 2 (model
site)
Not Proposed
Option 2
Option 2
Upgrade Option
Option 2
Option 2
Option 6
Option 6, 2 MGY
cutoff
NODA Costs ($2001)
Number
of Sites
1,521
2,354
Capital
Costs
215,372,532
545,616,505
O&M
Costs
406,618,406
718,480,881
NA
NA
24
1,270
6,136,725
252,665,620
3,952,333
167,585,291
NA
35
21,726,209
35,625,488
Final Rule Costs ($2001)
Number
of Sites
228
Capital
Costs
16,302,446
O&M
Costs
10,582,427
NA
429
628
65,548,547
95,760,054
36,159,912
40,732,283
NA
NA
314
19
51,694,660
2,473,423
11,409,399
6,584,137
NA
4
840
1,117,553
178,724,756
222,423
176,775,257
NA
41
112
2,749
288
12,089,100
19,399,831
14,578,563
16,338,598
28,744,590
22,760,945
34,841,549
94,408,489
NA
NA
354
51,588,250
17,942,002
Not Covered by MP&M
Not Covered by MP&M
2,382
6,505,602
13,110,283
NA
Technology
Basis for
Final Rule?
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
No

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                                                                                                            11.0 - Costs of Technology Bases for Regulations
                                                        Table  11-1 (Continued)
Subcategory
Railroad Line
Maintenance
Shipbuilding
Dry Dock
Discharge
Status
Direct
Indirect
Direct
Indirect
Options
Evaluated Since
Proposal
Option 10
Option 6
Not Proposed
Option 10
Not Proposed
NODA Costs ($2001)
Number
of Sites
31
Capital
Costs
5,941,283
O&M
Costs
3
NA
Final Rule Costs ($2001)
Number
of Sites
Capital
Costs
NA
9
O&M
Costs

See Footnote A
NA
6
601,172
3,152,880
6
See Footnote A
NA
Technology
Basis for
Final Rule?
No
No
No
No
No
Source: EPA Costs & Loadings Model.
Note: Cost estimates presented in this table will not equal those presented in the EEBA. These estimates do not include costs for facilities that are projected to
close in the baseline.
NA - Not applicable.
Footnote A - Based on DMR data received both from the model facilities and in comments, EPA considered the final removals to be negligible. Therefore, the
Agency did not calculate exact final costs.

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          Table 11-2
Incremental Annualized Costs
                                             11.0 - Costs of Technology Bases for Regulations
Subcategory
General Metals
Metal Finishing
Job Shops
Non-Chromium
Anodizing
Printed Wiring
Board
Steel Forming
and Finishing
Oily Wastes
Railroad Line
Maintenance
Discharge
Status
Direct
Indirect
Direct
Indirect
Direct
Indirect
Direct
Indirect
Direct
Indirect
Direct
Indirect
Direct
Indirect
Options Evaluated Since
Proposal
Option 2
Option 2, 1 MGY cutoff
Upgrade Option
50% Local Limits
Option 2
Option 2
Upgrade Option
Option 2 (model site)
Not Proposed
Option 2
Option 2
Upgrade Option
Option 2
Option 2
Option 6
Option 6, 2 MGY cutoff
Option 10
Option 6
Not Proposed
NODA Costs ($2001)
Number of
Sites
1,521
2,354
Annualized Costs
431,321,635
781,063,094
NA
NA
24
1,270
4,656,215
196,566,038
NA
35
38,117,484
Final Rule Costs ($2001)
Number of
Sites
228
Annualized Costs
12,452,318
NA
429
628
43,678,331
51,715,961
NA
NA
314
19
17,338,777
6,867,838
NA
4
840
350,606
197,274,986
NA
41
112
2,749
288
31
30,131,210
24,986,106
36,513,710
96,282,526
681,469
NA
NA
NA
354
23,859,174
Not Covered by MP&M
Not Covered by MP&M
2,382
13,856,475
NA
NA
9
See Footnote A
NA
Option
Promulgated?
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
No
No
No
No

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                                                                                                            11.0 - Costs of Technology Bases for Regulations
                                                        Table  11-2 (Continued)
Subcategory
Shipbuilding
Dry Dock
Discharge
Status
Direct
Indirect
Options Evaluated Since
Proposal
Option 10
Not Proposed
NODA Costs ($2001)
Number of
Sites
6
Annualized Costs
3,221,834
Final Rule Costs ($2001)
Number of
Sites
6
Annualized Costs
See Footnote A
NA
Option
Promulgated?
No
No
Source: EPA Costs & Loadings Model.
Note: Cost estimates presented in this table will not equal those presented in the EEBA. These estimates do not include costs for facilities that are projected to
close in the baseline.
NA - Not applicable.
Footnote A - Based on DMR data received both from the model facilities and in comments, EPA considered the final removals to be negligible. Therefore, the
Agency did not calculate exact final costs.

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                                                           11.0 - Costs of Technology Bases for Regulations

option considered following proposal of the rule and compares EPA's final cost estimates to
those presented in the NODA.  Cost estimates presented in this section differ from those
presented in the EEBA because of additional EEBA annual costs (e.g., taxes and amortization).
In addition, the EEBA cost estimates exclude facilities that EPA projected will close in the
baseline (i.e., facilities already financially stressed without the additional compliance costs
associated with this rule).  The remainder of this section discusses the methodology EPA used to
calculate its final cost estimates.  For a discussion of the costing methodology EPA used at
NODA, see Section 16 of the rulemaking record.

11.2          Development of Cost Model Inputs

              This subsection describes the key inputs to the cost model: model sites,
wastewater discharge parameters, pollutant concentrations, and technology in place.  This section
also discusses the data sources used to determine these parameters. Section 11.3 describes how
the cost model uses the input data.

11.2.1        Model Site Development

              The Agency used a model-site approach to estimate costs for the water-
discharging sites in the MP&M Point Source Category. A model site is an operating MP&M
survey site whose regulatory status, and unit operation and treatment information were used as
input to the cost model.  EPA selected a site-by-site model approach to estimate compliance
costs, as opposed to a more generalized approach, to better characterize the variability of both
process water and wastewater discharges in the MP&M industry. EPA selected 915 model sites
from the 1,563 sites returning surveys. EPA excluded sites if:

              •      The site's operations did not fall within the scope of this rulemaking;

              •      The site did not discharge wastewater (treated or untreated) to either a
                    surface water or publicly owned treatment works (POTW); or

              •      The site did not supply sufficient technical data to estimate compliance
                    costs and pollutant loading reductions associated with the technology
                    options.

              Each of the 915 facilities is considered a "model" facility for two reasons. First,
because only a portion of the MP&M universe was surveyed, each facility represents a larger
number of similar facilities in the overall industry population, as determined by its statistical
survey weight. Section 3.0 discusses the development of survey weights.  The surveyed sites
represent an estimated industry population of more than 44,000 sites that discharge either directly
to surface waters or indirectly through a POTW. Second, because only a portion of the MP&M
universe was sampled, EPA used its sampling data to model an aggregated influent to treatment
concentration for each survey site based on the survey subcategory and the unit operations the
site performs. Section 12.0 discusses the use of unit operation sampling data.  Additionally, the
                                           11-6

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                                                          11.0 - Costs of Technology Bases for Regulations

Agency made engineering assumptions based on national information from standard engineering
costing publications, equipment vendors, and industry-wide data. Thus, for any given model site,
the estimated costs and loads may deviate from those that the site would actually incur.
However, EPA considers the compliance costs to be accurate when evaluated on an industry-
wide, aggregate basis.

11.2.2        Wastewater Streams and Flow Rates

              EPA used wastewater discharge parameters (e.g., production rates,  flow, and
operation schedule) to calculate wastewater generation and discharge rates.  The cost model uses
these flow rates to estimate the capacity of treatment units needed for each wastewater stream.
Using information from  survey responses, follow-up letters, and phone calls, EPA first classified
each process wastewater stream by the type of unit operation generating the wastewater (e.g.,
machining, electroplating, acid treatment). For each unit operation, EPA then determined
production rate, operating schedule, wastewater discharge flow rate, and discharge destination.
Some sites provided all the information needed for each wastewater stream, but others did not.
EPA determined the wastewater discharge parameters as described below:

              •       Production rate. In survey responses, sites reported production rates in
                     surface area processed, mass of metal removed, or air flow rate, depending
                     on the unit operation.  Production  expressed in terms of surface area
                     represented surface finishing or cleaning operations;  mass of metal
                     removed represented metal  removal  operations  such  as machining and
                     grinding; and air flow rate represented air pollution control  operations.
                     For blank responses, EPA statistically imputed production rates using
                     other data provided in the site's survey or by using data for  similar unit
                     operations reported in other MP&M surveys. The general methodology as
                     well as specific production  calculations can be found in DCN 36200 in
                     Section 28.2 of the rulemaking record.

              •       Operating schedule.  EPA used survey responses to represent the
                     operating rate (hours per day (hpd) and days per year (dpy)) of each unit
                     operation.  For blank responses, EPA used the following:

                           The maximum hpd and dpy reported by the site for other unit
                           operations, if reported by the site, or

                           The survey response for wastewater treatment system operating
                           schedule,  if the site provided a wastewater treatment operation
                           schedule,  or

                           8 hpd and 260 dpy.  This estimate represents the median work
                           schedule for MP&M sites.
                                          11-7

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                                                          11.0 - Costs of Technology Bases for Regulations

              •      Wastewater discharge flow rate. For each process wastewater stream,
                    most sites reported the total wastewater discharge flow rate from the unit
                    operation and associated rinses. For sites that reported performing a unit
                    operation but did not report a discharge flow rate, EPA statistically
                    imputed wastewater flow rates using other data provided in the site's
                    survey or by using data for similar unit operations reported in other
                    MP&M surveys.  The general methodology as well as specific calculations
                    for sites' wastewater flow rates can be found in DCN 36200, in Section
                    28.2 of the rulemaking record.

              •      Discharge destination. EPA used survey responses to determine the
                    discharge destination of each unit operation (surface  water, POTW, no
                    discharge, contract haul, or other alternatives) and the level of treatment
                    prior to discharge (none, pollution prevention, chemical precipitation,
                    sedimentation, etc.). In many cases, a site had multiple discharge
                    destinations. EPA assumed no costs would be incurred at baseline for
                    wastewater streams not discharged to POTWs or surface waters (i.e., those
                    contracted for off-site disposal, deep-well injected, discharged to septic
                    systems, reused on site, or otherwise not discharged (recycled, evaporated,
                    etc.)). For sites that did not report a discharge destination for some or all
                    operations, EPA used other MP&M survey information (e.g., types of
                    discharge permits, discharge destination of other unit operations, process
                    flow diagrams) to determine the stream discharge destination. For details
                    on determination of site discharge destination, see Section 24.6.1 of the
                    rulemaking record, DCNs 17881,  17825, and 17826.

              EPA then used the completed wastewater discharge information to create the first
of three cost model input databases, Model Site Profile 1 (MSP1). Table 11-3 summarizes the
information contain in MSP1.

                                      Table 11-3

                          Information Contained in MSP1
Field Name
SitelD
UPNum
UPExt
UPRinse
Description
Random Site Identification Number assigned by EPA.
Unit operation number as reported in the survey. (See Section 4.0 for a list of unit operations
performed at MP&M facilities.)
Unit operation extension. Each unique unit operation was given a new extension (e.g., electroless
nickel plating might be UP20-1 and electroless copper plating might be UP20-2).
Unit operation rinse indicator. "0" designates a unit operation, "R" designates a unit operation
rinse.
                                          11-8

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                                                          11.0 - Costs of Technology Bases for Regulations
                               Table 11-3 (Continued)
Field Name
StreamID
SiteDest
Weights
FLOW
PROD
PNP
PNF
HPD
DPY
TANKVOL
NUMUNITS
BASEMET
METAPPL
DEST
RinseCode
Equipment
Code
MCTIP
IXTIP
PCTIP
Description
A consolidation of the fields UPNum, UPRinse, and UPExt used by the cost model
(UPNum+UPRinse"-"UPExt).
Overall site wastewater discharge destination as determined by the survey.
Industry Weighting Factor; this number indicates how many sites the survey represents on a
national basis (see Section 3.0 for more information).
Unit operation discharge flow in gallons per hour.
Unit operation production in PNP per hour.
Production-normalizing parameter; standard cubic feet per minute, square feet, or pounds of
metal removed depending on the unit operation.
Production-normalized flow, equivalent to FLOW/PROD.
Hours per day that the unit operation operates.
Days per year that the unit operation operates.
Unit operation tank volume in gallons.
Number of individual units represented by the unit operation (e.g., 30 machines performing the
same operation, operating the same hours and days, and using the same process chemicals would
be represented by one unit operation in MSP1 but would have a numunits of 30).
Base metal of the part on which the operation is being performed.
Metal being applied by the unit operation (where appropriate).
Stream discharge destination as determined by the detailed unit operation information.
Rinse water code used to determine the level of pollution prevention currently in place at the site.
Refer to Section 5.3.2.2 of the rulemaking record, DCN 15773, for specific code definitions.
Equipment code used to determine the amount of equipment currently in place at the site. Refer
to pollution prevention documentation for specific code definitions.
Indication of whether the stream has machine coolant treatment in place (yes/no).
Indication of whether the stream has ion exchange treatment in place (yes/no).
Indication of whether the stream has paint curtain treatment in place (yes/no).
11.2.3
Wastewater Pollutant Concentrations
             EPA developed pollutant concentrations for the model sites' wastewater streams.
The cost model tracks two concentrations for each wastewater stream: the baseline pollutant
concentration and the post-compliance pollutant concentration. The baseline pollutant
concentration represents what the site currently discharges. The post-compliance pollutant
concentration represents what the site would discharge after installing the regulatory option
technology.

             EPA assigned each wastewater stream a baseline pollutant concentration for each
pollutant of concern (POC) in the second input database named MSP2.  The cost model used this
                                          11-9

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                                                          11.0 - Costs of Technology Bases for Regulations

information to calculate both costs and pollutant loadings. The remainder of this section
describes how the cost model used pollutant concentration data to estimate costs.  Section 12.0
discusses how the cost model used these data to estimate pollutant loadings. Table 11-4
summarizes the information contained in MSP2.

                                      Table 11-4

                          Information Contained in MSP2
Field Name
SitelD
StreamID
PollCode
CHEM_NAM
PollConc
Description
Random Site Identification Number assigned by EPA.
A consolidation of the fields UPNum, UPRinse, and UPExt used by the cost model
(UPNum+UPRinse"-"UPExt).
Pollutant identification code (e.g., CU, NA, TS). Refer to analytical data documentation
(Section 5.3.2.2 of the rulemaking record, DCN 15773) for specific code definitions.
Chemical Name (e.g., copper, sodium, total suspended solids). Refer to analytical data
documentation for specific code definitions.
Pollutant concentration as defined through analytical data (mg/L). Refer to Section 12.0 for
concentration development information.
11.2.4
Technology in Place
              The term "technology in place" refers to those treatment technologies installed
and operating at a model site. EPA recognizes the importance of identifying which wastewater
streams were already being treated. For example, sites with technology in place that met or
exceeded the option technology would incur no additional costs, and sites with some technology
in place would need only parts of the option technology.  Sites with technology in place that met
or exceeded the option technology but did not treat all of the required streams with this
technology would incur costs to increase capacity, if required. Therefore, EPA identified
technology in place from survey responses, which documented the technology in place at the
time of the survey response. EPA's surveys cover two base years: 1989 and 1996. Because EPA
has two base years for this industry, where EPA received updated TIP information up to the later
base year of 1996, EPA incorporated this updated information in its analyses. The cost model
used these data to determine what components of the option technology a site would need, as in
Example 11-1 at the end of this section.

              The regulatory options include two types of wastewater treatment: (1) in-process
pollution prevention and source reduction (pollution prevention) and (2)  end of pipe. EPA
determined the technologies in place  for all unit operations, both pollution prevention and end of
pipe; however, some sites did not provide information on the pollution prevention technology in
place.  The following paragraphs describe in detail how EPA determined pollution prevention
technologies in place for these sites.
                                         11-10

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                                                         1 1 .0 - Costs of Technology Bases for Regulations

             Determination of Pollution Prevention Technology In Place

             Although both the 1989 and 1996 MP&M Detailed Surveys requested detailed
information on end-of-pipe treatment in place, only the 1996 MP&M Detailed Survey requested
information about a site's in-process pollution prevention technologies. Where available, EPA
determined pollution prevention technology in place based on survey responses (e.g., for all 1996
survey respondents). For other model sites, the Agency determined pollution prevention
technology in place based on other survey information. For example, EPA examined the model
site's production-normalized flow rate (PNF). The PNF is the volume of wastewater generated
per unit of production, as described in the following equation:
                                 PNF  -
                                          PROD

where:

             PNF   =      Production-normalized flow, gallons per ton;
             FLOW =      Annual wastewater discharge, gallons per year; and
             PROD =      Annual production, tons per year.

             Generally, the less wastewater generated per volume of production, the better the
pollution prevention technology in place.  Therefore, if the site PNF was below the median PNF
calculated for the industry for that pollution prevention technology, then EPA assumed the site
had the pollution prevention technology in place. For example, if a 1989 survey site reported a
machining wastewater stream with a PNF below the median PNF for centrifugation and
pasteurization of machining coolants, then the Agency assumed that the model site had a
machining coolant regeneration/recycling system in place. The median PNFs estimated for each
technology are detailed in Section 24.6.1 of the rulemaking record, DCN 17885.

             Determination of Rinse Scheme Technology In Place

             EPA used a similar method to determine which sites had efficient rinse schemes.
For unit operations without the option rinse technology in place, EPA estimated costs to install
and operate a two-stage countercurrent cascade rinse. EPA used the following parameters in
designing rinse technology upgrades:

             •      Rinse technology in place.  EPA determined which of the following rinse
                    technologies sites had in place:

                           Two overflow rinse tanks,
                           One overflow rinse tank,
                           One stagnant tank followed by one overflow tank,
                           One spray rinse, or
                           Two-stage countercurrent cascade rinsing.
                                         11-11

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                                                          11.0 - Costs of Technology Bases for Regulations

                    For sites that did not provide information on their rinse scheme, EPA
                    classified their rinse type based on the PNF for the industry. First EPA
                    calculated site-specific PNFs for all rinses with data.  Next, the Agency
                    calculated the median industry PNFs for each rinse type. Finally, EPA
                    assigned each unknown stream a rinse type corresponding to the stream's
                    PNF.

                    For more information on the median PNF calculations and the PNFs
                    associated with each rinse type, see Section 24.6.1 of the rulemaking
                    record, DCN 17885.

              •      Tank volume.  The cost model uses unit operation tank volume as a
                    design parameter for countercurrent cascade rinsing, but the Agency did
                    not request this information in the surveys. EPA estimated additional tank
                    volume needed based  on the annual discharge flow rate.

              EPA then estimated what new pollution prevention equipment a site would need
to meet the regulatory option.  Sites with countercurrent cascade rinsing in place would not
require rinse upgrades.  Sites with parts of countercurrent cascade rinsing, such as tanks but not
enough piping, were allocated costs for the piping and pumps needed. Additional information on
the rinse flow reduction methodology can be found in Section 24.6.1  of the rulemaking record,
DCN 17885.  Section 11.3.3 also discusses flow reduction methodology.

              Determination of End-of-Pipe Technologies in Place

              EPA reviewed survey data for each model site to assess the end-of-pipe
technologies in place (e.g., chemical reduction of chromium, sludge pressure filtration). EPA
found some technologies in place that were not part of the regulatory options but  achieve
removals equivalent to the option technology. For example, the Agency considered vacuum
filtration equivalent to pressure filtration for sludge dewatering. EPA also assumed that some
sedimentation  and oil treatment systems qualified  as treatment in place for multiple options. For
example, if a site had microfiltration in place for solids removal,  EPA considered that equivalent
treatment for either microfiltration or clarification. If a site had a clarifier in place, EPA
considered it equivalent for clarification, but not for  microfiltration. Table 11-5 lists the
technologies that EPA considered equivalent to the option technologies. EPA also found
technologies that it did not consider equivalent to option technologies. For example, EPA did
not consider oil/water separation equivalent to dissolved air flotation in the advanced technology
options. Conversely, the Agency considered dissolved air flotation to achieve equivalent or
better pollutant removals than oil/water separation. EPA assumed that sites specifying only
chemical precipitation also had a clarifier and vice versa. In addition, the Agency assumed sites
with treatment systems in place have the associated chemical feed systems.  Assumptions
regarding treatment technologies in place at each model site are discussed in detail in Section 6.5,
DCN 15799, and Section 24.6.1, DCN 17888, of the rulemaking record.
                                          11-12

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                                                          11.0 - Costs of Technology Bases for Regulations
                                      Table 11-5
  Treatment Technologies Considered Equivalent to the Option Technologies
Technology Specified by Option
Chelated metals treatment
Chemical emulsion breaking and gravity
oil/water separation
Chemical precipitation and
sedimentation
Chromium reduction
Clarification
Cyanide reduction
Dissolved air flotation
Filter press
Microfiltration for solids removal
Multimedia filtration
Sludge dewatering
Ultrafiltration for oil removal
Technologies Considered Equivalent or Better to the
Option Technologies
Chelated metals treatment
Chemical emulsion breaking and gravity oil/water separation
Chemical emulsion breaking and gravity flotation
Dissolved air flotation
General oil water separation*
Ultrafiltration
Chemical precipitation
Sites without chemical precipitation and
(1) with ion exchange were assumed to have technology equivalent to
chemical precipitation and clarification
(2) with dissolved air flotation assumed to have technology equivalent
to given chemical precipitation and clarificatiorf
(3) with pH adjustment and sludge dewatering/filter press were
assumed to have technology equivalent to chemical precipitation,
clarification, and sludge dewatering/filter pressa
Chromium reduction
Clarification
Microfiltration
Dissolved air flotation (where no other chemical precipitation is
present)3
Cyanide reduction
Ion exchange
Dissolved air flotation
Ultrafiltration
Filter press
Vacuum filtration
Microfiltration
Multimedia filtration
Sludge dewatering
Gravity thickener
Sludge settling tank
Ultrafiltration for oil removal
These technologies are considered equivalent only for the purpose of defining treatment in place, not as a proven
method of meeting the final limits.
                                          11-13

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                                                          11.0 - Costs of Technology Bases for Regulations

             EPA also used survey data to determine the capacity of the end-of-pipe
technologies in place at the model sites for the following parameters:

             •      Operating schedule. EPA used the operating schedule (hpd and dpy) for
                    each treatment unit supplied by sites. For blank responses, EPA
                    determined the schedule using the following:

                           The maximum hpd and dpy reported for other treatment units,

                           The maximum hpd and dpy reported for the unit operations, if all
                           hpd and dpy responses for all treatment units  were blank,

                           The maximum hpd and dpy reported by the site for other unit
                           operations associated with other treatment units, or

                           8 hpd and 260 dpy, if all hpd and dpy survey  responses were blank
                           for unit operations and treatment units.

             •      Wastewater streams treated.  For blank responses,  EPA determined
                    which wastewater streams were treated by the technology in place using
                    survey process flow diagrams or survey responses regarding the
                    destination of individual process wastewater streams. If this information
                    was not provided, EPA used the cost model logic described in  Section
                    11.3 to help assign streams to technologies (e.g., EPA assumed that
                    cyanide-bearing streams were treated through cyanide destruction, if the
                    site currently had it in place).

             EPA used the operating schedule and wastewater stream  flows treated by the
technology to define the capacity needed for each technology using the following equation:
                               V x SA =

where:

             V     =      Volume of tank needed, gallons;
             SA    =      Surface area of tank, gallons per foot;
             Q     =      Discharge flow, gallon per minute; and
             HLR  =      Hydraulic loading rate. EPA set the HLR to 1,000 gallons per
                           square foot per day.

             The Agency determined  design capacity from one of two flows:  the survey-
provided design capacity flow (when available) or the model design capacity flow as derived
from the 122 percent of baseline flow.  The methodology for calculating the model flow is
                                         11-14

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                                                          11.0 - Costs of Technology Bases for Regulations

discussed in detail in Section 11.3.4. EPA also accounted for those sites that may need to
increase wastewater treatment capacity as a result of the process changes associated with some of
EPA's technology options. Section 11.3.4 presents how EPA accounted for baseline end-of-pipe
technologies with insufficient capacity. Also, more details on capacity calculations are in
Section 6.7, DCN 15902, and Section 24.6.1, DCN 17903, of the rulemaking record. All stream-
by-stream treatment-in-place information was then incorporated into the final input database
MSP3. Table 11-6 summarizes the information contained in MSP3.

                                      Table 11-6

                          Information Contained in MSP3
Field Name
SitelD
UPNum
UPPrefix
UPExt
OldExt
UPSuffix
StreamID
MODULE
HPD
DPY
SITEDCF
DCF
Description
Sited Identification Number assigned by EPA.
Unit operation number as reported in the survey.
Identifier that indicates if the UPNum refers to a unit operation, in-process pollution prevention
operation, or treatment unit. EPA used this field to aid in the creation of MSP3 (e.g., UP or TU).
Unit operation extension. Each unit operation was given a new extension (e.g., electroless nickel
plating might be UP20-1 and electroless copper plating might be UP20-2).
Field used in the creation of MSP 1 and MSP3.
Unit operation rinse indicator. "0" designates a unit operation, "R" designates a unit operation
rinse.
A consolidation of the fields UPNum, UPRinse, and UPExt used by the cost model
(UPNum+UPRinse"-"UPExt).
Indicates which treatment units the site currently has in place.
Hours per day that the treatment unit operates.
Days per year that the treatment unit operates.
The design capacity flow reported by the site in survey data (gph).
The design capacity flow populated during cost model operation. This is equivalent to the larger
of the following: the sitedcf or a minimum dcf calculated in the cost model. Refer to cost model
documentation (Section 24.6. 1, DCN 17890) for complete DCF creation information (gph).
11.2.4.1
Baseline Model Runs
              The baseline run simulated the current treatment practices at each model site. The
cost model uses baseline costs to determine the incremental costs for each regulatory option.
EPA first performed a baseline run of the cost model to determine the following parameters:

              •      Estimated baseline O&M costs incurred by sites in 2001 dollars;

              •      Estimated baseline non-water quality impacts such as electricity usage,
                    sludge generation, and waste oil generation;
                                          11-15

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                                                           11.0 - Costs of Technology Bases for Regulations

              •       Estimated baseline pollutant effluent concentrations (see Section 12.0);
                     and

              •       Capacity flow rate of each wastewater treatment technology in place.

11.2.4.2       Post-Compliance Model Runs

              Following the baseline model run, EPA then ran a post-compliance cost model
run for each regulatory option. Each cost model run calculated the following values:

              •       Incremental capital investment costs incurred by sites in 2001 dollars;

              •       O&M costs incurred by sites  in 2001 dollars;

              •       Non-water quality impacts such as electricity usage, sludge operation, and
                     waste oil generation; and

              •       Pollutant loadings discharged after installation of the option technology
                     (see Section 12.0).

              EPA calculated incremental O&M costs as the difference between baseline and
post-compliance, using the following equation:

                  O&M CostSlncremental = O&M CostsTreated - O&M CostsBaseline            (11-3)

EPA used the same methodology to calculate incremental values for non-water quality impacts
and pollutant loadings.

11.2.4.3       New Source Model Runs

              EPA also ran new source cost model runs for the General Metals, Metal Finishing
Job Shops, Non-Chromium Anodizing, Printed Wiring Board, and Oily Wastes Subcategories.
These runs estimated the costs a new source would incur in meeting the new source standards
considered for Part 438.  Model sites were used to calculate total construction and operating costs
associated with a brand new treatment system  consisting of the appropriate option technology.
Each cost model run calculated the following values:

              •       Total, rather than incremental, capital investment costs incurred by sites in
                     2001;

              •       Total, rather than incremental, O&M costs incurred by sites in 2001
                     dollars;
                                          11-16

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                                                             11.0 - Costs of Technology Bases for Regulations

              •      Total, rather than incremental, monitoring costs incurred by sites in 2001
                     dollars;

              •      Non-water quality impacts such as electricity usage, sludge operation, and
                     waste oil generation; and

              •      Pollutant loadings discharged after installation of the option technology
                     (see Section 12.0).

              The model estimated total costs for new sources to meet the considered 438
limitations as follows:
Subcategory"
General Metals
Metal Finishing Job
Shops
Non-Chromium
Anodizing
Printed Wiring Board
Oily Wastes
Discharge
Destination
Direct
Indirect
Direct
Indirect
Direct
Indirect
Direct
Indirect
Direct
Indirect
Number of
MP&M Sites
794
10,307
12
1,542
Capital Costs
($2001)
116,844,985
1,851,638,823
5,546,098
372,340,073
Annual Costs
($2001)
310,919,560
2,268,371,865
2,612,444
276,027,559
Annualized
Costs ($2001)
324,321,680
2,480,754,838
3,248,581
318,734,965
None Identified
122
8
818
2,585
26,608
76,369,114
3,128,633
230,533,415
79,678,368
575,295,361
112,525,473
2,697,791
255,151,103
101,830,335
1,629,178,524
121,285,010
3,056,645
281,593,286
110,969,444
1,695,164,902
aEPA did not perform new source cost model runs for the Railroad Line Maintenance or Shipbuilding Dry Dock
Subcategories because, as discussed in the preamble to the final rule, EPA determined that national regulation of
discharges in these subcategories is unwarranted at this time.

              Note that for metal-bearing subcategories, EPA then costed new sources to
operate two separate chemical precipitation and solids separation steps in series.  This was done
to address concerns raised by commentors that  single-stage precipitation and solids separation
may not achieve sufficient removals for wastewaters that contain significant concentrations of a
wide variety of metals that precipitate at disparate pH ranges.  To calculate the addition of a
second stage of treatment, EPA doubled the original treatment costs.
11.3
General Methodology for Estimating Costs of Treatment Technologies
              This subsection discusses the methodology for estimating costs, including the
components of cost (Section 11.3.1), the sources and standardization of cost data (Section
11.3.2), the cost model (Section 11.3.3), and assumptions made during the costing effort (Section
11.3.4).
                                           11-17

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                                                          11.0 - Costs of Technology Bases for Regulations

11.3.1         Components of Cost

              The components of the capital and annual costs and the terminology used in
developing these costs are presented below.

              Capital Investment Costs

              The capital investment costs consist of two major components:  direct capital
costs and indirect capital costs. The direct capital costs include:

              •      Purchased equipment cost, including ancillary equipment (e.g., piping,
                    valves, controllers);

              •      Delivery cost (based on the equipment weight and a shipping distance of
                    500 miles); and

              •      Installation/construction cost (including labor and site work).

              EPA derived the direct components of the total capital cost separately for each
treatment unit or pollution prevention technology.  When  possible, EPA obtained costs for
various sizes of preassembled, skid-mounted treatment units from equipment vendors. If costs
for these units were not available, EPA obtained catalog prices for individual system components
(e.g., pumps, tanks, feed systems) and summed these prices to estimate the cost for the treatment
unit.

              Indirect capital costs consist of secondary containment, engineering, contingency,
and contractor fees. These costs together with the direct capital costs form the total capital
investment. EPA estimates the indirect costs as percentages of the total direct capital cost, as
shown in Table 11-7.

              Annual Costs

              Annual costs include the following:

              •      Raw material costs - Chemicals and other materials used in the treatment
                    processes (e.g., sodium hydroxide,  sulfuric acid, sodium hypochlorite);

              •      Operating labor and material costs - The labor and materials directly
                    associated with operation of the process equipment;

              •      Maintenance labor and material  costs - The labor and materials required
                    for repair and routine  maintenance  of the equipment;
                                          11-18

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                                                        11.0 - Costs of Technology Bases for Regulations

                    Energy costs - Calculated based on total energy requirements (in kiloWatt
                    hours (kW-hrs)); and

                    Monitoring and analytical costs - The periodic sampling and analysis of
                    wastewater effluent samples to ensure that discharge limitations are being
                    met.

                                     Table 11-7
                    Components of Total Capital Investment
Item
Number
1
2
3
4
5
6
7
8
9
10
11
Item
Equipment capital costs including
required accessories
Site work, including demolition,
concrete repair, and build out
Shipping cost, based on weight of
equipment and 500-mile shipping radius
Installation, based on estimated number
of hours for each technology at a rate of
$29.67/hour
Direct capital cost
Engineering/administrative and legal
costs
Secondary containment/land costs
Total plant cost
Contingency
Contractor's fee
Total capital investment
Cost
Total equipment cost
3% of total equipment cost
Technology-specific cost,
see individual cost module
Technology-specific cost,
see individual cost module
Sum of items 1 through 4
10% of item 5
10% of item 5
Sum of items 5 through 7
15% of item 8
5% of item 8
Sum of items 8 through 10
Source
MP&M cost model capital
cost curves
Attachment 1
(DCN 16027, Section 6.7.1)
Attachment 2
(DCN 16027, Section 6.7.1)
MP&M cost modules

Attachment 1
(DCN 16027, Section 6.7.1)
Attachment 3
(DCN 16027, Section 6.7.1)

Attachment 1
(DCN 16027, Section 6.7.1)
Attachment 1
(DCN 16027, Section 6.7.1)

11.3.1.1
Total Annualized Costs
             EPA calculated total annualized costs (TAG) from the capital and annual costs.
The Agency assumed a 7-percent discount rate over an estimated 15-year equipment life,  using
the following equation:

      Annualized Cost = (Incremental Capital Cost) x 0.1147 + (Incremental Annual Cost)(ll-4)
                                        11-19

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                                                         11.0 - Costs of Technology Bases for Regulations

11.3.2        Sources and Standardization of Cost Data

             EPA obtained capital and annual cost data for the technologies that constitute
EPA's technology options (see Section 9.0) from equipment vendors, literature, and MP&M
sites. The Agency used specific data from the 1989 and 1996 MP&M Detailed Surveys
whenever possible; however, the required types of data were  often either not collected or not
supplied by the sites.  The major sources of capital cost data were equipment vendors, while the
literature sources provided most of the annual cost information.

             •      Capital Equipment. EPA obtained information on capital equipment
                    from vendors in 1998; specific cost estimates for technologies are included
                    in Section 6.7.1 of the rulemaking record.

             •      Chemicals. EPA used the Chemical Marketing Reporter from December
                    1997 to obtain chemical prices (2). A  list is in Section 6.7.1 of the
                    rulemaking record, DCN 15890.

             •      Water and Sewer Costs. EPA based  water and sewer use prices on
                    average data collected through an EPA Internet search of various public
                    utilities located throughout the United  States for years ranging from 1996
                    to 1999. The average water and sewer use charges were $2.03 per 1,000
                    gallons and $2.25 per 1,000 gallons, respectively. The results of the
                    Internet search can be found in Section 6.7.1 of the rulemaking record,
                    DCN 15890.

             •      Energy. EPA used average electricity prices from the U.S. Department of
                    Energy's Energy Information Administration.  The average electrical cost
                    to industrial users from 1994 to 1996 was $0.047 per kW-hr (see Section
                    6.7.1 of the rulemaking record, DCN 15890).

             •      Labor. EPA used a labor rate of $29.67 per hour to convert the labor
                    requirements of each technology into annual costs. The Agency obtained
                    the base labor rate from the Monthly Labor Review, which is published by
                    the U.S. Bureau of Labor Statistics of the U.S. Department of Labor.
                    Excluding the maximum and minimum values, EPA used the largest
                    remaining monthly value for 1997 for  production labor in the fabricated
                    metals industry, $12.90 per hour, as a conservative estimate.  The Agency
                    added 15 percent of the base labor rate for supervision and 100 percent for
                    overhead to obtain the labor rate of $29.67 per hour (3). See Section 6.7.1
                    of the rulemaking record, DCN 15890.

             •      Off-Site Treatment/Disposal.  EPA estimated average costs of
                    contracting for off-site waste treatment/disposal using data from the 1996
                    MP&M Detailed and Screener Surveys, as discussed in Section 11.4.4.
                                         11-20

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                                                         11.0 - Costs of Technology Bases for Regulations

                    The Agency estimated costs to dispose of RCRA hazardous metal
                    hydroxide sludge from Pollution Prevention and Control Technology for
                    Plating Operations (4). Table 11-8 presents the treatment/disposal costs
                    for various waste types.  See Section 6.7.1 of the rulemaking record, DCN
                    16023.

             •      Monitoring Costs. MP&M effluent monitoring costs were developed
                    based on sampling frequency, the cost per analysis, and the labor to collect
                    the samples. Monitoring costs vary depending on the current regulatory
                    status of the facility. The following subsections describe the MP&M
                    monitoring frequency requirements and the estimated incremental
                    monitoring costs for each MP&M subcategory.

                                     Table 11-8

  Costs for Contracted Off-Site Treatment/Disposal of Various Waste Types
Waste Type
RCRA hazardous nonhazardous paint sludge
RCRA hazardous metal hydroxide sludge (3)
RCRA nonhazardous oil
Solvent (paint and paint stripping waste)
Oily wastewater
General metal-bearing wastewater
Cyanide-bearing wastewater
Hexavalent chromium-bearing wastewater
Chelated metal-bearing wastewater
Cost ($/gallon)
3.70
1.95
0.86
2.85
1.33
2.00
5.64
3.51
1.40
           Source: 1996 MP&M Detailed and Screener Surveys.

             EPA standardized capital and annual cost data to 1996 dollars (the most current
year for which EPA collected survey data). Final industry cost estimate numbers are then
converted to 2001 dollars using the Engineering News-Record Construction Cost Index. For
cases where EPA's information is not representative of 1996, EPA adjusted the cost estimates
using RS Means Building Construction Historical Costs as shown in Table 11-9 (see Section
6.7.1 of the rulemaking record, DCN 15890).
                                         11-21

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                                                          11.0 - Costs of Technology Bases for Regulations
                                      Table 11-9
            RS Means Building Construction Historical Cost Indexes
Year
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
Index
92.1
94.3
96.8
99.4
101.7
104.4
107.6
110.2
112.8
114.4
           Source: Historical Cost Indexes, RS Means Building Construction Cost Data.
           56th Annual Edition, 1998, page 594 (1).

             Monitoring Frequency for Metal-Bearing Subcategories

             When developing costs for the Part 438 effluent limits considered for the metal-
bearing subcategories, EPA considered a monitoring frequency of once per week for regulated
pollutants.  EPA calculated the costs for the Part 438 limitations assuming the monitoring
frequencies listed in Table 11-10.  See Section 24.6.1 of the rulemaking record, DCN 17911.

             Sampling and Analysis Costs

             EPA developed sampling labor and equipment requirements based on its
experience gained during the MP&M sampling episodes. The Agency determined laboratory
analysis costs for each regulated pollutant by contacting PEL Laboratories in Tampa, Florida.
Using the monitoring frequency, labor hours to collect samples, the loaded labor rate
($29.67/hour), and the cost per analysis, EPA estimated the annual monitoring costs for various
facilities.
                                         11-22

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                                                         11.0 - Costs of Technology Bases for Regulations
                                     Table 11-10
  Monitoring Frequencies Used to Develop Part 438 Limitations Considered
                         for Metal-Bearing Subcategories
Regulated Pollutant
Cadmium
Chromium
Copper
Lead
Nickel
Silver
Tin
Zinc
Cyanide (total)
Oil and grease (as HEM)
pH
Total Toxic Organic (TTO)
parameter1
Sample Type
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Composite
Grab
Composite
Grab
Samples/week









4
1
0
Samples/month
4
4
4
4
4
4
4
4
4
12
4
1
Samples/year
48
48
48
48
48
48
48
48
48
192
48
12
aSum of volatile organics, semivolatile organics, pesticides and PCBs.

             Incremental monitoring costs for metal-bearing MP&M facilities depended on
their current regulatory status.  Incremental costs for facilities currently regulated by Part 433 or
assumed to be meeting Part 433 (e.g., direct-discharging facilities in the General Metals
Subcategory) to comply with the limits considered for existing and new source Part 438 resulted
from:

             •      Adding tin to the list of regulated pollutants;

             •      Lowering the effluent limit for lead, which requires analysis by graphite
                    furnace atomic adsorption ($28/sample) rather than inductively coupled
                    plasma ($20/sample); and

             •      Increasing the number of samples for oil and grease from one to four
                    during each sampling event.

             Incremental sampling labor costs result from the need to collect four oil  and
grease samples rather than one during the facility's daily processing period.  The annual
incremental monitoring cost for a Part 433 facility to comply with the limits considered for Part
438 were approximately $22,000 for the metal-bearing subcategories (see Section 24.6.1 of the
rulemaking record, DCN 17911). These incremental monitoring costs are conservative (e.g.,
some Part 433 facilities may be currently collecting four oil  and grease grab samples per
monitoring day and some that generate oily waste may have either implemented an Organics
Management Plan or are already collecting 12 TTO samples per year).
                                         11-23

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                                                             11.0 - Costs of Technology Bases for Regulations

              Costs for new source facilities (not including existing facilities that become new
source facilities) result from the purchase or rental of sampling equipment, sampling labor, and
laboratory analysis. The monitoring and analytical cost for these new source facilities to comply
with the considered effluent limits was $41,000 for the metal-bearing subcategories (see Section
24.6.1 of the rulemaking record, DCN 17911).

              Monitoring Frequency for Oil-Bearing Subcategories

              EPA evaluated monitoring frequency separately for the Oily Wastes, Railroad
Line Maintenance, and Shipbuilding Dry Dock Subcategories due to the high percentage of
survey- and comment-supplied DMR sampling data in each of these subcategories. One hundred
percent of the direct discharging railroad line maintenance facilities supplied sampling data and
some associated sampling frequency information.  Ninety-two percent of the direct discharging
oily wastes facilities, with treatment in place, supplied sampling data and some associated
sampling frequency information. Fifty percent of the shipbuilding dry dock facilities supplied
sampling data and some associated sampling frequency information.

              Direct discharging MP&M facilities in the Oily Wastes Subcategory will be
required to monitor their discharges for total suspended solids (TSS) and oil and grease.  Based
on the supplied information, for the Part 438 limitations, EPA calculated incremental monitoring
costs assuming all direct discharging facilities are currently analyzing at least one  TSS and oil
and grease sample per month. Therefore, incremental monitoring costs for these facilities is
zero1.  Monitoring frequencies are determined by the permit writer and must be a minimum of
once per year. The monitoring frequency specified in MP&M National Pollutant Discharge
Elimination System (NPDES) permits will vary depending upon the size of the facility, potential
impacts on receiving waters,  compliance history, and other factors, including monitoring policies
or regulations required by permit authorities. EPA encourages permit writers to require all
facilities subject to the Part 438 limitations to collect a minimum of one TSS and oil and grease
sample per month. Facilities may monitor more frequently than specified in their permits;
however, the results must be  reported in accordance with Part 122.41 (l)(4)(ii) for direct
dischargers.
'Based on the information in its database, EPA concludes most facilities currently collect one sample per month.
During EPA sampling events, EPA collected four grab samples at each sampling point each day.  These samples
were analyzed individually with the results composited mathematically to obtain a single daily concentration for each
pollutant at each sampling point.  While the final limitations are based on these composited values, the analytical
method allows a facility to composite multiple grab samples prior to analysis. Therefore, analytical costs should
remain constant for these facilities even if permit writers require them to collect a composite, rather than grab
sample.

                                           11-24

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                                                          11.0 - Costs of Technology Bases for Regulations

11.3.3        Development of the Cost Model

              The cost model consists of the following programming components:

              •      Model shell;
              •      Model drivers;
              •      Data storage files; and
              •      Technology modules.

              The model shell includes a program that creates various menus and user interfaces
that accepts user inputs and passes them to the appropriate memory storage areas. The model
drivers are programs that access technology modules in the proper order for each option and
process model-generated data.  Data storage files are databases that contain cost model input and
output data. Information typically stored in data storage files includes:

              •      Flow, production, and operating data associated with each wastewater
                    stream;

              •      Pollutant concentrations associated with each wastewater stream; and

              •      Site-specific data regarding existing technologies in place (discussed in
                    Section 11.2.4).

              Technology modules are programs that calculate costs and pollutant loadings for a
particular pollution control technology.  EPA developed cost modules for the pollution
prevention and end-of-pipe technologies included in the regulatory options for the MP&M
industry.

              The technology drivers perform the following functions for each technology
costed for a site (if applicable):

              •      Locate and open necessary input data files;
              •      Store input data entered by the user;
              •      Open and run the appropriate technology modules; and
              •      Calculate and track model outputs.

              Table 11-11 lists the treatment technology modules that are used in the cost
model. Section 11.5 discusses the technology modules.

              In the context of the MP&M cost program, "model" refers to the overall computer
program and "module" refers to a computer subroutine that 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).  EPA adapted some modules from previous
                                          11-25

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                                                             11.0 - Costs of Technology Bases for Regulations

EPA rulemaking efforts for the metals industry and developed others specifically for this
rulemaking effort.

                                       Table 11-11

           Wastewater Treatment Technologies and  Source Reduction
        and Recycling Practices for Which EPA Developed Cost Modules
     In-Process Technologies and Practices
                                    End-Of-Pipe Technologies and Practices
 Countercurrent cascade rinsing
 Centrifugation and pasteurization of machining
 coolants
                            Chemical reduction of hexavalent chromium
                            Cyanide destruction
                            Chemical reduction of chelated metals
                            Chemical emulsion breaking and gravity oil/water separation
                            Chemical emulsion breaking and dissolved air flotation
                            Gravity oil emulsion breaking (baseline only, see
                              Section 11.3.4)
                            Ultrafiltration for oil removal
                            Contract hauling of solvent degreasing wastewaters
                            Chemical precipitation
                            Inclined clarification for solids removal
                            Microfiltration for solids removal
                            Sludge thickening
                            Sludge pressure filtration
                            Multimedia filter (baseline only, see Section 11.3.4)
Source: MP&M Surveys, MP&M Site Visits, Technical Literature.
11.3.3.1
Modeling Technology Options
              The model drivers access technology modules in the proper order for each
technology option (e.g., in-process flow control and pollution prevention followed by end-of-pipe
treatment). The drivers' logic dictates which unit operations feed which treatment technologies.
EPA assumed wastewater destination based on unit operation wastewater characteristics:
cyanide-bearing wastewater feeds cyanide destruction and flowing rinses feed countercurrent
cascade rinsing. Table 11-12 lists the assigned unit operations feeding each treatment
technology. Note that a unit operation can feed more than one treatment technology or in-
process pollution prevention technology. EPA assumed that the model sites commingled all
MP&M wastewater generated for treatment by chemical precipitation, inclined clarification or
microfiltration for solids removal, sludge thickening, and sludge pressure filtration, except for
wastewater from the Oily Wastes, Shipbuilding Dry Dock, and Railroad Line Maintenance
Subcategories, and except for solvent-bearing wastewater, for which EPA estimated costs for off-
site disposal.
                                           11-26

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                                      11.0 - Costs of Technology Bases for Regulations
                    Table 11-12

List of Unit Operations Feeding Each Treatment Unit
             or In-Process Technology
Treatment Technology/Pollution
Prevention Technology
Countercurrent cascade rinsing
Unit Operations Feeding Technology3
Acid treatment with chromium rinse
Acid treatment without chromium rinse
Alkaline cleaning for oil removal rinse
Alkaline treatment with cyanide rinse
Alkaline treatment without cyanide rinse
Anodizing with chromium rinse
Anodizing without chromium rinse
Aqueous degreasing rinse
Barrel finishing rinse
Chemical conversion coating without chromium rinse
Chemical milling rinse
Chromate conversion coating rinse
Corrosion preventive coating rinse
Electrochemical machining rinse
Electroless plating rinse
Electrolytic cleaning rinse
Electroplating with chromium rinse
Electroplating with cyanide rinse
Electroplating without chromium or cyanide rinse
Electropolishing rinse
Heat treating rinse
Salt bath descaling rinse
Solvent degreasing rinse
Stripping (paint) rinse
Stripping (metallic coating) rinse
Testing rinse
Washing finished products rinse
Carbon black deposition rinse
                        11-27

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                            11.0 - Costs of Technology Bases for Regulations
Table 11-12 (Continued)
Treatment Technology/Pollution
Prevention Technology
Countercurrent cascade rinsing (cont.)
Centrifiguration and pasteurization of
machining coolant
Centrifugation of painting water curtains
Chemical emulsion breaking and oil/water
separation
OR
Dissolved air flotation
OR
Ultrafiltration system for oil removal
Unit Operations Feeding Technology3
Galvanizing/hot dip coating rinse
Mechanical plating rinse
Laundering rinse
Cyanide rinsing
Ultrasonic machining rinse
Phosphor deposition rinse
Multiple unit operation rinse
Grinding
Machining
Painting - spray or brush
Painting - immersion
Alkaline cleaning for oil removal and rinse
Alkaline treatment without cyanide
Aqueous degreasing
Assembly/disassembly
Electrical discharge machining rinse
Electrolytic cleaning
Electroplating without chromium or cyanide
Floor cleaning and rinse
Grinding
Grinding rinse
Heat treating
Impact deformation and rinse
Machining and rinse
Painting - spray or brush
Painting - immersion
Pressure deformation
Steam cleaning rinse
Stripping (paint)
           11-28

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                                                                    11.0 - Costs of Technology Bases for Regulations
                                   Table 11-12 (Continued)
Treatment Technology/Pollution
Prevention Technology
Chemical emulsion breaking and oil/water
separation
OR
Dissolved air flotation
OR
Ultrafiltration system for oil removal
Chemical reduction of hexavalent chromium
Chemical reduction of chelated metals
Cyanide destruction
Solvent hauling
Unit Operations Feeding Technology3
Stripping (metallic coating) rinse
Testing
Thermal cutting rinse
Washing finished products and rinse
Bilge water
Mechanical plating
Photo image developing
Photo imaging
Steam cleaning
Vacuum impregnation
Laundering
Calibration
Centrifugation and pasteurization of machining coolant
Acid treatment with chromium and rinse
Anodizing with chromium and rinse
Chromate conversion coating and rinse
Electroplating with chromium and rinse
Stripping (paint)
Wet air pollution control - chromium
Chromium drag-out reduction and rinse
Electroless plating and rinse
Alkaline treatment with cyanide and rinse
Electroplating with cyanide and rinse
Cyanide rinsing and rinse
Cyanide drag-out destruction and rinse
Wet air pollution control - cyanide
Solvent degreasing
aA unit operation can feed more than one treatment technology or in-process pollution prevention technology. EPA
assumed that the model sites commingled all MP&M wastewater generated for treatment by chemical precipitation,
inclined clarification or microfiltration for solids removal, sludge thickening, and sludge pressure filtration, except
for wastewater from the Oily Wastes, Shipbuilding Dry Dock, and Railroad Line Maintenance Subcategories, and
except for solvent-bearing wastewater, for which EPA estimated costs for off-site disposal.
                                                 11-29

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                                                          11.0 - Costs of Technology Bases for Regulations

11.3.3.2      Modeling Flow Reduction

             Figure 11-2 shows the logic used by the cost model to apply the in-process flow
reduction to each model site. EPA estimated flow reductions resulting from applying in-process
pollution prevention technologies to any streams that did not already have the technology in
place (see  Section 11.2.4).  The estimated flow reductions are as follows:

             •      EPA estimated a 20- to 80-percent flow reduction achieved by converting
                    the current rinse scheme in place to countercurrent cascade rinsing (DCN
                    15993, Section 6.7.1 of the rulemaking record and Section 15.0 of this
                    document and 1996 survey data). The flow reduction applied depends on
                    the rinse scheme currently in place. An 80-percent flow reduction
                    corresponds to converting a high-flow two-stage continuous overflow
                    rinse to a two-stage countercurrent cascade rinse. A  20-percent flow
                    reduction corresponds to converting a stagnant rinse  followed by a
                    continuous overflow rinse to a two-stage countercurrent cascade rinse.
                    EPA computed the flow reductions based on information collected in the
                    MP&M surveys.

             •      EPA assumed that centrifugation and pasteurization of machining coolants
                    reduced coolant use by 80 percent (see Section 6.7.1  of the rulemaking
                    record, DCN 15802). EPA assumed that a site combined all wastewater
                    from machining operations prior to centrifugation and pasteurization of
                    machining coolants.

             •      EPA assumed that centrifugation of painting water curtains allowed 100
                    percent reuse of the treated wastewater in the painting booth, or zero
                    discharge (sludge removed from the centrifuge is contract hauled). EPA
                    assumed a site combined wastewater from painting streams prior to paint
                    curtain centrifugation.

11.3.3.3      Modeling End-of-Pipe Treatment for Metal Bearing Subcategories

             The logic used by the model drivers to access end-of-pipe technologies varies
depending on whether the subcategory is primarily metal bearing or oil bearing. Figure 11-3
presents the logic used by the cost model to apply the end-of-pipe treatment technologies and
practices for the following  metal-bearing wastewater subcategories: General Metals, Metal
Finishing Job Shops, Non-Chromium Anodizing, Printed Wiring Board, and Steel Forming and
Finishing.  In developing costs, EPA assumed sites would segregate wastewater streams
according to pollutant characteristics (chromium, cyanide, chelated metals,  oil, and solvent).
Segregating wastewater streams provides the most efficient and  effective treatment of wastes.
Because treating solvent-bearing waste streams may require Treatment Storage and Disposal
(TS&D) permitting, EPA assumed model sites would contract for off-site disposal of solvent-
bearing wastewater streams, while the other segregated wastewater streams would receive
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                                                           11.0 - Costs of Technology Bases for Regulations

preliminary treatment.  The cost model assumed that effluent from preliminary treatment
technologies would be combined with other wastewater streams that did not require preliminary
treatment prior to estimating the cost of treating the combined wastewater.  Model drivers also
direct treatment unit order; for example, sludge from chemical precipitation goes to thickening
and pressure filtration prior to off-site disposal. EPA assumed wastewater from chemical
precipitation and sedimentation systems would be discharged to either a surface water or POTW
according to the model site's current discharge destination (see Section 11.3.4 for general
discharge status assumptions for sites with multiple discharge destinations).

11.3.3.4       Modeling End-of-Pipe Treatment for Oily Subcategories

              The model drivers access modules to simulate oily wastewater treatment.  Figure
11-4 presents the logic used to apply the end-of-pipe treatment technologies and pollution
prevention  practices for the Oily Wastes, Railroad Line Maintenance, and Shipbuilding Dry
Dock Subcategories.  Each of these subcategories generates wastewater that primarily contains
oily constituents and low concentrations of dissolved metals; therefore, EPA did not include
chemical precipitation and sedimentation following oil treatment for these subcategories.

11.3.3.5       Model Output

              The model drivers track output including the following site-specific information
for each technology:

              •      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;
              •      Chemical usage reduction and associated cost credit;
              •      Effluent flow rate; and
              •      Effluent pollutant concentrations.

Section 11.6 discusses calculation specifics for each technology module.

11.3.4        General Assumptions Made During the Costing Effort

              This subsection presents general assumptions that EPA included in the cost
model.  Section 11.4 discusses specific assumptions made for NODA and post-NODA analyses.
Section 11.6 discusses technology-specific assumptions.
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                                                          11.0 - Costs of Technology Bases for Regulations

              Baseline Year Determination

              EPA estimated costs for the MP&M industry for the base years 1989 and 1996
(the years in which survey data were collected). The Agency included sites (or operations) that
operated during the 1989 and 1996 calendar years in the cost and loadings analyses if the site
operated at least one day during the respective calendar year. If a site (or operation) shut down
before 1996, it was removed from the costing and pollutant loadings analyses. If a site (or
operation) commenced after 1989 (Phase I) or 1996  (Phase II), EPA did not include the site (or
operation) in the costing or pollutant loadings analyses. See Section 3.1 for additional
information regarding EPA's use of 1996 as the base year for its analyses for this rule.
Furthermore, if a site did not discharge wastewater to surface water or a POTW in 1989 (Phase I)
or 1996 (Phase n) (e.g., was a zero or alternative discharger), then EPA  excluded the site from
the costing and pollutant loadings analysis.

              If EPA has information that a Phase I site installed or significantly altered its
wastewater treatment systems before 1996, EPA used the updated data.  Also, if a site changed
its discharge status before 1996, EPA used the updated discharge status  in its analyses. Some
sites provided information during the comment period that corrected information submitted with
their survey. For example, a Phase 1 site may have completed its survey as having no treatment
for oily discharges but submitted information during comment that it had installed treatment
prior to 1996.  In these cases, EPA revised the input data to reflect the corrected site information.

              Capacity of End-of-Pipe Technology in Place

              For sites with technology in place, EPA assessed the design capacity flow for each
treatment unit using the derived design capacity flow from the larger of two values:  the site's
reported survey design capacity flow or the flow calculated by the cost model baseline run, as
described in Section 11.2.4, assuming the baseline flow is 78 percent of the design capacity flow.
MP&M survey data indicate, on average, that flow entering the treatment units is 78 percent of
the design flow reported by the survey respondent. Therefore, rather than assuming that the site
is operating at 100 percent of the design capacity when survey information is unavailable, EPA
assumed the site is operating at 78 percent of the design capacity.  Therefore, flows can increase
by as much as 22 percent over the current flow before  either additional treatment capacity or
contract hauling is required (see Section 6.7 of the rulemaking record, DCN 15902). The Agency
determined the need for greater capacity using the following logic:

              •       If the technology was not in place at the model site, then EPA assigned
                     capital costs to the site for a treatment unit of sufficient capacity.

              •       If the technology was in place at the model site with sufficient capacity to
                     treat all of the applicable MP&M wastewater, then EPA assigned no
                     additional  capital costs.
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                                                           11.0 - Costs of Technology Bases for Regulations

              •      If the site had a technology in place equivalent to the option technology
                    but with insufficient capacity to treat all the applicable MP&M
                    wastewater, then EPA assumed the site would operate the existing system
                    at full capacity.  EPA assigned costs for the option technology train to run
                    in parallel with the existing treatment to handle the additional flow.

              Contracting for Off-Site Treatment/Disposal in Lieu of Treatment

              EPA assessed the cost to contract for off-site treatment/disposal of wastewater
compared to on-site treatment. Because many MP&M sites have flow rates less than the
minimum design capacity for treatment, EPA determined that some model sites would contract
for off-site disposal of wastewater rather than treat it on site. If off-site disposal was less
expensive than treatment on site, EPA assumed the site would dispose of the wastewater off site.
EPA compared off-site disposal versus on-site treatment for individual technologies and their
influent flow rates, rather than on the total site wastewater treatment system.  For example, a site
may find it less expensive to contract for off-site disposal of cyanide-bearing wastewater than to
install and operate a cyanide destruction treatment system. However, it would still be less
expensive to treat all other wastewater streams on site. To determine whether treatment on site
was less expensive then contracting for off-site disposal, EPA compared total annualized costs
assuming an equipment life expectancy of 15 years and an annual interest rate of 7 percent.

              EPA used MP&M survey data to determine the unit cost ($/gal or $/lb)
to contract for off-site treatment/disposal for various waste types (see Section 6.7.1 of the
rulemaking record, DCN 16023). EPA compared the costs  of the following technologies to
contracting for off-site disposal in lieu of treatment costs:

              •      Centrifugation and pasteurization of machining coolants;

              •      Centrifugation of painting water curtains (general metal-bearing waste and
                    paint sludge);

              •      Chemical reduction of hexavalent chromium;

              •      Cyanide destruction;

              •      Chemical reduction of chelated metals;

              •      Chemical emulsion breaking and gravity oil/water separation;

              •      Dissolved air flotation;

              •      Ultrafiltration for oil removal;
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                                                         11.0 - Costs of Technology Bases for Regulations

             •      Chemical precipitation and sedimentation; and

             •      Sludge pressure filtration.

             In the case of wastewater requiring chemical precipitation and sedimentation
treatment, EPA compared the costs of contracting for off-site disposal of the untreated end-of-
pipe wastewater to the cost of the entire treatment system, which includes chemical precipitation,
sedimentation (gravity clarification or microfiltration), sludge thickening, and pressure filtration.

             Equipment Size Ranges

             EPA developed equipment cost equations for each component of the treatment
technologies. The equations are valid between the minimum and maximum sizes (e.g., flow
rates, volume capacities) from which EPA developed the equations. For wastewater capacities
below the minimum range of validity, the cost model designed the equipment at the minimum
size. For wastewater capacities above the maximum range of validity, the cost model designed
multiple units of equal capacity to operate in parallel.

             Batch Schedules

             EPA designed either batch or continuous systems, depending on each model site's
operating schedule and discharge flow rate.  The Agency also designed wastewater treatment
operations such that the minimum system would be operated at capacity. For example, if the
minimum cyanide destruction system was 480 gallons per batch, and a site generated 80 gallons
of cyanide-bearing wastewater per day, then the cost model designed the cyanide destruction
system to treat a 480-gallon batch once every six days.

             Dilute Influent Concentrations

             In rare cases, high wastewater flow rates at some sites resulted in pollutant
concentrations below the long-term average technology effectiveness concentrations (discussed
in Section 10.0) even after flow reduction from in-process pollution prevention practices. In
these cases, EPA assumed the site did not require treatment to meet the EPA option for that
wastewater stream and therefore did not include end-of-pipe costs.

11.4         Specific  Methodology and Assumptions Used to Estimate Costs for
             Treatment Technologies

             EPA made many changes in cost model assumptions and methodology made
based on comments submitted during both the proposed rule and the NODA comment periods.
This subsection describes the changes to proposal methodology and assumptions that EPA used
to estimate both the costs presented in the NODA and those developed for the final rule. The
methodology and assumptions used for the costs presented in the Development Document for the
Proposed Effluent Limitations Guidelines and Standards for the Metal Products & Machinery
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                                                          11.0 - Costs of Technology Bases for Regulations

Point Source Category (EPA 821-B-00-005) are discussed in that document.  EPA updated
information regarding unit operations, discharge status, operating schedule, and flow throughout
the costing effort, based on industry comments and corrections to submitted survey data.

11.4.1         NODA Cost Estimates

              For the costs presented in the NODA, EPA revised the following inputs and logic
of the proposed cost model:

              •      Pollutant concentration;
              •      Subcategorization scheme;
              •      Discharge status;
              •      Wastewater treatment determination;
              •      Wastewater flow;
              •      Treatment modules;
              •      Statistical weighting factors; and
              •      Post processing.

              EPA also added an option:  upgrading treatment from 40 CFR 413 standards to
those of 40 CFR 433.  The remainder of this subsection describes all these changes in detail.

              Pollutant Concentrations

              EPA revised the calculation of pollutant concentrations from unit operations.
First, the Agency incorporated additional data submitted with comments and from the Phase in
sampling (see Section 3.0 for details on data sources). Next, EPA reclassified sampling data unit
operations, including revising one sample point to be a drag-out rinse and adding more printed
wiring board unit operations (see  Section 12.0 for details). See Section 24.7 of the rulemaking
record, DCN 17890, for details of these changes.

              Subcategorization Scheme

              In response to industry comments, EPA made the following adjustments to the
Subcategorization scheme for analyses presented in the NODA:

              •      Printed Wiring Board Assembly facilities in the Metal Finishing Job
                    Shops Subcategory were moved to the General Metals Subcategory.
                    Facilities that perform only Printed Wiring Board Assembly operations
                    remained in the General Metals Subcategory.

              •      Printed Wiring Board Job Shops were moved from the Metal Finishing
                    Job Shops Subcategory into the Printed Wiring Board Subcategory.
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                                                           11.0 - Costs of Technology Bases for Regulations

              •      Additional unit operations were included in the Oily Wastes Subcategory
                    based on new sampling data and data submitted with comments.

              •      Zinc platers were defined and segregated from the General Metals and
                    Metal Finishing Job Shops Subcategories for some analyses for EPA's
                    consideration of a zinc platers subcategory or segment.

              Discharge Status

              For NOD A analyses, EPA revised the discharge status determination for sites
submitting MP&M Phase I surveys to better reflect the MP&M Phase II discharge status
hierarchy. The discharge status for all sites was thus based on the following assumptions:

              •      EPA considered a site with a direct discharging stream as direct, regardless
                    of any indirect or zero-discharging streams (i.e., all streams at the site were
                    considered to be direct);

              •      EPA considered a site with an indirect discharging stream and no direct
                    streams as indirect, regardless of any zero-discharging streams;  and

              •      EPA considered a site with no direct or indirect streams a contract-haul,
                    reuse, or zero-discharge site.

              Wastewater Treatment Determination

              EPA updated the treatment in place based on the following additional comment
data and new assumptions:

              •      In response to industry comments, EPA considered end-of-pipe ion
                    exchange equivalent to cyanide destruction for sites discharging cyanide-
                    bearing wastewater.  See Section 20.3 of the rulemaking record, DCN
                    17947, for the industry comment information.

              •      For sites responding to the Short and Municipality Surveys, EPA no longer
                    considered neutralization/pH adjustment equivalent to chemical
                    precipitation. EPA considered only neutralization/pH adjustment with
                    clarification or  sludge removal equivalent to chemical precipitation.

              •      EPA assumed that sites with baseline pollutant concentrations less than the
                    option technology pollutant concentrations did not require any additional
                    treatment.

              •      EPA verified cost model input database accuracy versus the site surveys
                    and resolved inconsistencies, such as stream discharge destination.
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                                                         11.0 - Costs of Technology Bases for Regulations

             Wastewater Flow

             EPA revised flow imputations for sites not reporting unit operation discharges.
The sum of imputed flows was verified to be less than the total reported facility flow, where
available.  Additionally, EPA excluded recirculated flow from the imputation to reduce the
potential for overinflated imputations. See Section 16.6.1 of the rulemaking record, DCN 27711.

             Statistical Weighting Factors

             EPA incorporated new statistical weighting factors. The Agency adjusted some
Phase I survey weights to account for additional zero dischargers and to exclude ineligible
facilities.  See Section 19.5 of the rulemaking record, DCN 36086.

             Post Processing

             EPA adjusted model logic, allowing treatment costs to be estimated on individual
wastestreams for the Railroad Line Maintenance and Steel Forming and Finishing Subcategories.
 EPA also allowed for cost savings from the addition of pollution prevention technologies.

             40 CFR 413 to 433 Upgrade Analysis

             To consider the industry comment that the proposed standards were too stringent,
EPA examined a new option: to upgrade from the 40 CFR 413  standards to 40 CFR 433
standards. EPA approximated compliance costs and load reductions associated with upgrading
facilities from the Electroplating (40 CFR 413) rule to the Metal Finishing (40 CFR 433) rule.
The 40 CFR 413 rule, promulgated in 1981, is based on older technology than the 40  CFR 433
rule, promulgated in 1983.  Section 9.0 presents the option technology associated with the Part
413 to 433 Upgrade Analysis.  Section 11.5  discusses how EPA estimated costs for each
component of the option technology,  and Section 12.0 discusses how EPA estimated the
pollutant loadings reductions associated with the Upgrade Analysis.

11.4.2        Post-NODA Cost Estimates

             Following receipt of industry comment on the analyses presented in the NOD A,
EPA revised parts of the costing approach. The remainder of this subsection describes the
changes made between the NODA and promulgation:  how EPA incorporated new data received
and revised assumptions and parts of the costing methodology.

             Treatment Modules Updates

             EPA revised and updated treatment modules. Most notably, EPA added
monitoring costs for tin, sulfide, and lead for all sites.  EPA revised the off-site disposal
methodology to haul nickel-bearing wastewater prior to chemical precipitation if the model
determines not to treat via chemical precipitation and sedimentation. EPA also added costs for
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                                                          11.0 - Costs of Technology Bases for Regulations

sand (multimedia) filters as a technology option. For more details on these and other revisions,
refer to Section 16.6.1, DCN 16741, and Section 24.6.1, DCN 17935,  of the rulemaking record.

              Discharge Status

              Post-NODA, EPA altered its discharge status determination to allow a site to have
multiple discharge statuses (e.g., direct discharge, indirect discharge, and zero discharge). The
approach was changed to more accurately reflect the actual site situation.  At the time of the
proposed rule and the NOD A, EPA classified discharge status for an entire site, instead of each
wastestream. For analyses after the NOD A, EPA assigned a discharge status to each wastewater
treatment system.

              Flow Estimates

              EPA revised the flow imputation methodology used to  estimate flows for sites that
did not provide them.  The new methodology allowed for zero discharge as a possible imputation
result.  See Section 28.2 of the rulemaking record, DCN 36200 for more detail on imputed flows.

              Treatment in Place

              In response to industry comments to ensure proper consideration of the baseline
treatment in place, EPA reconsidered additional treatment technologies equivalent to the option
technologies:

              •       EPA now considers end-of-pipe and in-process ion exchange equivalent to
                     cyanide destruction for cyanide-bearing wastestreams without any other
                     cyanide treatment;

              •       EPA now considers end-of-pipe and in-process ion exchange equivalent to
                     chemical precipitation plus a filter press for metals-bearing wastestreams
                     without other metals treatment;

              •       Dissolved air flotation is considered equivalent to chemical precipitation
                     treatment for metals-bearing wastestreams without other metals treatment
                     for the 413 to 433 Upgrade option;

              •       Any type of oily wastewater treatment (e.g., belt skimming) is equivalent
                     to chemical emulsion breaking and oil/water separation; and

              •       The presence of a holding tank and sludge removal after some chemical
                     addition is now considered equivalent to chemical  precipitation followed
                     by clarification.
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                                                          11.0 - Costs of Technology Bases for Regulations

11.5          Costing Methodologies for Direct Discharging Oil-Bearing Subcategories

              Commentors supplied additional DMR and sampling data during the post-
proposal and post-NODA comment periods.  Due to the small number of model facilities in each
of the oil-bearing subcategories and the high percentage of supplied DMR sampling data, EPA
was able to use site-specific effluent discharge information as a major part of the costing process.
(One hundred percent of the direct discharging railroad line maintenance facilities supplied
sampling data and some associated sampling frequency information.  Ninety-two percent of the
direct discharging oily wastes facilities, with treatment in place, supplied sampling data and some
associated sampling frequency information. Fifty percent of the shipbuilding dry dock facilities
supplied sampling data and some associated sampling frequency information.) The methodology
used in each of the oil-bearing subcategories is discussed below.

11.5.1         Oily Wastes Costing Methodology

              For the Oily Wastes Subcategory, EPA calculated the costs for the final rule
through the following methodology. If a model site had provided DMR data, it was reviewed to
determine baseline compliance with the final MP&M LTAs. If the data indicated the model site
was currently meeting the LTAs, no additional costs were applied to the site. If the DMR data
indicated the model site was not currently meeting the LTAs, and the  survey indicated that the
facility had Option 6 technology (or equivalent) in place, then the cost model output was
reviewed.  If the model determined that pollution prevention (P2) could be added to the site, then
only P2 costs were assigned. It was assumed that adding P2 would lower the flow into the
treatment system and help increase the system removals.  If the site already had P2 in place, then
a one-time upgrade cost was added. This upgrade cost was intended to help the facility better
operate their treatment system through use of a consultant, subsequent operator training, and
some additional treatment control equipment. The upgrade was considered a capital cost and
totaled $10,700 ($2001). This is made up of the costs listed below (for more details on how each
of these costs were derived,  see DCN  17906 located in Section 24.6.1 of the rulemaking record):

              •      $5,500 for consultant fees;
              •      $2,200 for operation training; and
              •      $3,000 for a new pH meter.

If the DMR data indicated the model site was not currently meeting the LTAs, and the survey
indicated that the facility did not have Option 6 technology (or equivalent) in place, then the cost
model output was used.

              If the model site did not have DMR data, it was reviewed to determine the level of
treatment in place. If the survey indicated the facility did have Option 6 technology (or
equivalent) in place, then EPA set the  baseline discharge concentrations to the median of the
DMR data. Because the calculated medians for oil and grease and TSS were below the final
MP&M LTA's, no additional costs were added. (Note that, if they had been above the final
MP&M LTA's, then EPA would have added a one-time upgrade cost.) If the survey indicated
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                                                          11.0 - Costs of Technology Bases for Regulations

the facility did not have Option 6 technology (or equivalent) in place, then the cost model output
was used.

11.5.2        Railroad Line Maintenance Costing Methodology

              For the Railroad Line Maintenance (RRLM) Subcategory, the AAR survey
information discussed in Section 3.0 was used.  Each survey contained information on effluent
concentrations, flow, and treatment currently in place. The AAR surveys indicated that all direct
discharging facilities in the RRLM Subcategory currently use wastewater treatment equivalent to
or better than Option 6. Additionally, most of the facilities have NPDES daily maximum permit
limitations for oil and grease (as HEM) and TSS as 15 and 45 mg/L, respectively. Based on this
information, EPA concluded that these oil and grease (as HEM) and TSS daily maximum limits
represent the average of the best performances of facilities utilizing Option 6 technology.

              EPA evaluated the compliance costs associated with establishing BPT daily
maximum limitations equivalent to 15 and 45 mg/L for oil and grease (as HEM) and TSS,
respectively, and concluded all facilities currently meet a daily maximum oil and grease limit of
15 mg/L and most currently monitor once per month. With one exception, all facilities are
currently meeting a TSS daily maximum limit of 45 mg/L. If EPA had decided to develop Part
438 limitations for this Subcategory, it would have estimated incremental costs associated with
bringing this one facility into compliance with the TSS limit.

11.5.3        Shipbuilding Dry Dock Costing Methodology

              No additional costs were estimated for this Subcategory. Following proposal,
EPA received comments and supporting data indicating that its estimates of current pollutant
discharges from this Subcategory were overestimated. In particular, commentors claimed that
current discharges of oil and grease were minimal and that national regulation was not warranted
for this Subcategory.  EPA incorporated the additional information provided by commentors into
its analysis and now concludes that direct discharges from these facilities generally contain
minimal levels of all pollutants.  In particular,  current oil and grease discharges from these
facilities are not detectable (< 5 mg/L) or nearly not detectable. EPA has similarly determined
that TSS discharges are, on average, minimal. The data show that TSS discharges may increase
episodically, particularly when the dry dock is performing abrasive blasting operations. However,
EPA has concluded that these episodic discharges from six facilities do not warrant national
regulation. If EPA had decided to develop Part 438 limitations for this Subcategory, it would
have estimated incremental costs associated with lowering and/or controlling the episodic TSS
discharges.

11.6          Design and Costs of Individual Pollution Control Technologies

              This subsection discusses in detail the design and costing of the individual
technologies that compose the technology options. Table 11-13 presents the capital and annual
cost equations for the specific equipment mentioned in each technology description below. When
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                                                          11.0 - Costs of Technology Bases for Regulations

tanks were a component of an option, EPA estimated that each wastestream would need only one
tank, unless the technology required a reserve tank, such as chemical emulsion breaking. EPA
estimated the tank volume needed based on Equation 11-2 in Section 11.2.4. The remainder of
this subsection describes the tank requirements of each individual technology. Additional
documentation is available in Section 24.6.1 of the rulemaking record, DCN 17885.

11.6.1        Countercurrent Cascade Rinsing

             The Agency estimated costs for countercurrent cascade rinses for flowing rinses at
the model sites. The countercurrent cascade rinse module estimates a cost and flow reduction
associated with the conversion to a two-stage countercurrent rinse. Section 15.2.4 gives more
information on countercurrent cascade rinsing flow reduction as related to the site's existing rinse
scheme.

             EPA estimated capital and annual costs based on the model site's current rinse
schemes. The module included capital and annual costs for the following equipment when
necessary.

             •     A second rinse tank with a volume equal to the volume of the existing
                    tank;

             •     Transfer pumps and piping; and

             •     An air-agitation system.

             EPA assumed there would not be additional O&M costs for replacing the current
rinse scheme with a two-stage countercurrent cascade rinse. Direct annual costs for this module
included increased energy costs but a reduced water cost due to water-use reduction. EPA
calculated the water savings obtained from converting the rinse to countercurrent cascade and
used a water cost of $2.03 per 1,000 gallons to subtract the cost savings from the site's total
annual cost.

11.6.2        Centrifugation and Pasteurization  of Machining Coolant

             EPA estimated costs for centrifugation and pasteurization  of machining coolant
for machining and grinding operations discharging water-soluble or emulsified coolant (listed in
Table 11-13). EPA estimated the costs of a liquid-liquid separation centrifuge to remove solids
and tramp oils and a pasteurization unit to reduce microbial growth. The costed systems
included the following equipment in Table 11-13:

             •     High-speed, liquid-liquid separation centrifuge;
             •     Pasteurization unit; and
             •     Holding tanks for large-volume applications.
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                                                          11.0 - Costs of Technology Bases for Regulations

              EPA provided a 50-percent excess capacity to account for fluctuations in
production resulting from flow rates greater than 14 gallons per minute. The Agency developed
capital and annual cost estimates from vendor data on packaged systems of different capacities.
Direct annual costs included O&M labor and materials, energy costs, sludge and waste oil
disposal costs, and a cost credit for water- and coolant-use reduction. EPA estimated
maintenance labor at one hour per week and operating labor at one hour per shift.

              Based on site visit and vendor information, EPA assumed that this technology can
reduce coolant discharge by 80 percent. The Agency based the amount of coolant and water
saved on the model site recycling 80 percent of the coolant and discharging a 20-percent
blowdown stream to oil treatment. From site visit and vendor information, EPA estimated the
coolant solution to be 95 percent water and 5 percent coolant.

11.6.3        Centrifugation of Painting Water Curtains

              EPA estimated costs for centrifugation of painting water curtains (listed in Table
11-13), which included a centrifuge and a holding tank large enough to hold flow for one hour.
Direct annual costs included O&M labor and materials, energy costs, sludge disposal costs, and a
cost credit for water-use reduction. EPA estimated maintenance labor at  one hour per week and
operating labor at one hour per shift.

              EPA assumed that a model site reused all water discharged from the
centrifugation system in painting operations, andxontracted for off-site disposal of the sludge
from the system. EPA estimated off-site disposal costs using the average paint sludge hauling
costs reported in the 1996 MP&M Detailed Survey. Because actual disposal costs depend more
on site-specific conditions (e.g., paint type and spray-gun cleaner requirements) than RCRA
hazard classification, EPA estimated costs by averaging the costs for RCRA hazardous and
nonhazardous paint sludges together.  (See Table 11-14 for off-site disposal costs and Section
11.6.4 for more detailed information.)
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                                       11.0- Costs of Technology Bases for Regulations
            Table 11-13
MP&M Equipment Cost Equations3
Equipment
Countercurrent cascade
rinsing



Machine coolant
regeneration system
(including holding tanks)





Paint curtain centrifuge





A =
C =
C =
c =
A =
c =
c =
c =
c =
c =
A =
c =
c =
c =
c =
Equation
[(0.0004 x TANKVOL + 0.2243)] x DPY x HPD x 0.047
- [(Y-CCFLOW) x 60 x HPD x DPY x 0.00203]
6.047 x TANKVOL + 3,784.3; Tank, piping, and pump
0.5077 x TANKVOL + 1077.8; Piping and pump
8 x 29.67; Labor only
[18 x 0.047 x DPY x HPD x NUM] + [(HPD/8) x DPY x 29.67 x NUM] + [(DPY/5) x 29.67
x NUM] + [0.002 x Y x 60 x HPD x DPY x 1.95]+ [0.05 x Y x 60 x HPD x DPY x 0.86] -
[0.05 x 0.80 x Y x 60 x HPD x DPY x 9.03] - [0.95 x 0.8 x Yx 60 x HPD x DPY x 0.00203]
41,422
	 . 	 1
110,205
142,831
164,009
191,331
[0.047 x KW x HPD x DPY] + [(HPD/8) x DPY x 29.67] + [(DPY/5) x 29.67]
+ [TSS x 3.785/106 x 2.2/0.4 x Y x 60 x HPD x DPY/8.5 x 3.7]
- [(Y x 60 x HPD x DPY) - (TSS x 3.785/106 x 2.2/0.4 x Y x 60 x HPD x DPY/8.35)] x
0.00203
	 1
7,254 (kW = 0.4)
10,325 (kW= 1.5)
47,104(kW = 2.2)
62,936 (kW = 3. 7)
Range of Validity




Y<14
\. 	
Y< 1
\. 	
1
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                                    11.0- Costs of Technology Bases for Regulations
Table 11-13 (Continued)
Equipment
Feed system, aluminum
sulfate (alum)




Feed system, calcium
chloride, continuous

Feed system, calcium
hydroxide (lime),
continuous



Feed system, ferric
sulfate, continuous




A =
C =
C =
A =
A =
C =
A =
C =
C =
A =
C =
C =
A =
C =
A =
C =
C =
A =
C =
Equation
0.35 x 0.7456 x HPD x DPY x 0.047
6,622
142.88 xY + 6,412
[1.36 x HPD x DPY x 0.047] + [0.0006615 x Y x 60 x HPD x DPY] + [(HPD/8) x DPY x
29.67] + [(DPY/5) x 29.67]
[1.49 x HPD x DPY x 0.047] + [0.0006615 x Y x 60 x HPD x DPY] + [(HPD/8) x DPY x
29.67] + [(DPY/5) x 29.67]
9.7882 xY + 9,718.7
[[(0.0061 x Y) + 1. 1696] x HPD x DPY x 0.047] + [0.00125 x Y x 60 x HPD x DPY]
10,299
28.805 xY+ 10,683
0.25 x 0.7456 x HPD x DPY x 0.047
8,489
47.713 xY + 8,445
[[(0.0006 x Y) + 1.2961] x HPD x DPY x 0.047] + [0.0001 17 x Y x 60 x HPD x DPY]
24.586 xY+ 12,830
0.35 x 0.7456 x HPD x DPY x 0.047
5,200
52.991 xY + 5,118
[[(0.0009 x Y)+ 1.33 13] x HPD x DPY x 0.047] + [0.0000434 x Y x 60 x HPD x DPY]
1 1.56 xY + 9,762.9
|



















Range of Validity
Y<10
Y< 1
1 350
10 < Y< 350
Y< 350
Y< 10
10
-------
                                    11.0- Costs of Technology Bases for Regulations
Table 11-13 (Continued)
Equipment
Feed system, polymer



Feed system, sodium
hydroxide, continuous
(caustic)


Feed system, sulfuric
acid


Chemical emulsion
breaking, coalescent
plate separator (gravity
oil/water separator)
[requires sulfuric acid,
alum, caustic, and
polymer feed systems]


Dissolved air flotation
[requires lime, ferric
sulfate, and polymer
feed systems]


A =
C =
A =
C =
A =
C =
A =
C =
A =
C =
A =
C =
A =
C =
C =
A =
C =
C =
See
A =
C =
Equation
[0.2833 x HPD x DPY x 0.047] + [0.001 x Y x 60 x HPD x DPY]
3,686
[[(0.0034 x Y) + 1.4171] x HPD x DPY x 0.047] + [0.001 x Y x 60 x HPD x DPY]
20.685 xY + 9,822
[0.1864 x HPD x DPY x 0.047] + [0.0042 x Y x 60 x HPD x DPY]
4,503
[[(0.0071 x Y) + 1. 1584] x HPD x DPY x 0.047] + [0.0042 x Y x 60 x HPD x DPY]
77.564 xY + 21,506
[0.0373 x HPD x DPY x 0.047] + [0.000222 x Y x 60 x HPD x DPY]
4,110
[[(0.0023 x Y) + 1.683] x HPD x DPY x 0.047] + [0.000222 x Y x 60 x HPD x DPY]
56.416 xY+ 17,769
[(0.0019 x Y + 2.009) x 0.7456 x HPD x DPY x 0.047] x NUM + [29.67 x (HPD/8) x DP\
+ [(DPY/5) x 29.67] x NUM + [3.664 x Y x HPD x DPY]
42,261
3,916.2 x Y + 30,278 + 2,452 x Y +1,132
[(0.096 x Y + 2.039) x 0.7456 x HPD x DPY x 0.047] x NUM + [29.67 x (HPD/8) x DPY]
+ [(DPY/5) x 29.67] x NUM + [3.664 x Y x HPD x DPY]
86,720
845.43 x Y + 65,284 + 2,452 x Y + 1,132
ultrafiltration for oil removal.
[(0.0728 x Y + 3.072) x HPD x DPY x 0.047] + [0.0045 x Y x 60 x HPD x DPY] + [29.67
HPD x DPY] + [(DPY/5) x 29.67] + [0.86 x 0.0003 x Y x 60 x HPD x DPY] + [0.86 x 0.0'
x Y x 60 x HPD x DPY]
1, 125.4 xY+ 137,936
|












1






x
71

Range of Validity
Y<10

10 < Y< 350

Y<10

10 < Y< 350

Y<10

10 < Y< 350

Y< 8
Y<2
2
-------
                                    11.0- Costs of Technology Bases for Regulations
Table 11-13 (Continued)
Equipment
Ultrafiltration for oil
removal
Batch oil-emulsion
breaking with gravity
flotation [requires
sulfuric acid, alum, and
polymer feed systems]
Chromium reduction
system, sodium
metabisulfite
Alkaline chlorination
with hypochlorite feed
system (for cyanide
destruction)
Chelation breaking with
dithiocarbamate
treatment

A =
C =
C =
See dissolved
A =
C =
A =
C =
C =
A =
C =
C =
A =
C =
C =
Equation
[(0.71 x Y + 5.46) x HPD x DPY x 0.047] +
[(DPY/5) x 29.67] + [65.78 x Y + 193.46] +
HPD x DPY]
157,700
3,596 xY + 235,146
air flotation.
[(0.65 x Y + 49.7) x HPD x DPY x 0.047] +
[0.022 x Y x 60 x HPD x DPY x 0.86]
17,204 xY + 2,000,000
[2.4225 x HPD x DPY x 0.047] + [0.002608
29.67] + [(DPY/5) x 29.67]
20,892
261.7 xY + 24,249
1
[0.4 x Y + 0.3] + [0.5 x HPD x DPY x29.67] +
[(27,123 x Y/(24 x 365 x 60)) x 0.86 x 60 x
4.


[HPD x DPY x 29.67] + [(DPY/5) x 29.67] +

x Y x 60 x HPD x DPY] + [(HPD/8) x DPY x


[4.845 x HPD x DPY x 0.047] + [0.012418 x Y x HPD x DPY x 60] + [0. 125 x HPD x DPY
x 29.67] + [(DPY/5) x 29.67]
28,862
29,793 xY°'19
[2.4225 x HPD x DPY x 0.047] + [0.000583
29.67] + [(DPY/5) x 29.67]
20,892
261.7 xY + 24,249


x Y x 60 x HPD x DPY] + [(HPD/8) x DPY x


Range of Validity
Y<406
Y< 8
8 < Y < 406
Y<100
100 < Y < 300
Y<45
Y< 1
1
-------
                                    11.0- Costs of Technology Bases for Regulations
Table 11-13 (Continued)
Equipment
Chemical precipitation
[requires sulfuric acid,
caustic and polymer
feed systems]


Clarifier, slant-plate
(lamella)


Filtration, multimedia


Microfiltration system
for metals removal


Sludge thickening




A =
C =
C =
A =
C =
A =
C =
C =
c =
A =
c =
c =
A =
c =
c =
A =
c =
A =
C =
Equation
[0.932 x HPD x DPY x 0.047] + [(DPY/5) x 29.67] + [(HPD/8) x DPY x 29.67]
8,900
626.6 xY + 8,550
[[(0.0571 x Y) + 0.0123] x HPD x DPY x 0.047] + [(DPY/5) x 29.67] + [(HPD/8) x DPY
29.67]
784.54 xY + 34,216
2 x (DPY/5) x 29.67
9,740
15,057
74.896 xY + 31,401
[[(0.0504 x Y) + 1.0139] x HPD x DPY x 0.047] + [(HPD/8) x DPY x 29.67] + [(DPY/5)
29.67]
35,115
240.85 xY + 27,269
[(0.3 x Y + 6.3) x HPD x DPY x 0.047] + [3.4 x Y] + [0.5 x HPD x DPY x 29.67] +
[(DPY/5) x 29.67] + [184.2 x Y + 155.2]
74,081
1,728.3 xY + 69,337
[0.246 x HPD x DPY x 0.047] + [2 x (DPY/5) x 29.67]
74.306 xYx60 + 3,746
[3.7 x HPD x DPY x 0.047] + [2 x (DPY/5) x 29.67]
2334.8 xY + 77,429
|

	
	
x
	

	
	
	
X
	
	

	
	

	

	
Range of Validity
Y<5
Y<0.5
0.5
-------
                                                                                                       11.0- Costs of Technology Bases for Regulations
                                                             Table 11-13 (Continued)
Equipment
Filter press, plate-and-
frame



A =
A =
A =
C =

[(60 + (30
[(60 + (60
[(60 + (90
[1,658.8 x

x DPY
xDPY
xDPY
FT3] +

X 2)) 3
x2))x
x2))x
17,505
Equation
•c NUM] + [FT3
NUM] + [FT3 x
NUM] + [FT3 x


xDPY
DPYx
DPYx


x7.48
7.48 x
7.48 x


x
1
1


1.95]
95]
95]

|
	 L.
	 L.
	 L.
	 1
Range of Validity
CFT3 < 6
CFT3 < 12
CFT3 > 12
0.85 < FT3 < 76.5
oo
aAll costs are calculated in 2001 dollars.

Variable Definitions:
C              - Direct capital costs (1996 dollars).
A              - Annual costs (1996 dollars).
Y              - Influent equipment flow (gallons per minute).
HPD           - Operating hours per day.
DPY           - Operating days per year.
FT3            - Daily cake volume (FT3) from all presses.
IPFLOW       - GPH
TANKVOL     - Volume of countercurrent rinsing tank (gallons).
CCFLOW      - Flow rate after countercurrent rinsing is supplied (gallons per minute).
kW            - Kilowatts.
CFT3          - Cake volume (FT3) per cycle per press (assume two cycles per day).
NUM          - Number of units.
TSS            - Influent TSS concentration (mg/L).

-------
                                                         11.0 - Costs of Technology Bases for Regulations

11.6.4        Contracting for Off-Site Treatment and Disposal

             The Agency estimated costs for off-site treatment and disposal of various types of
wastes generated on site. These waste types include:

             •      Painting and paint stripping/solvent wastewater;
             •      Paint sludge;
             •      Wastewater containing oil and grease and organic pollutants;
             •      Waste oils/sludges;
             •      Chromium-bearing wastewater;
             •      Cyanide-bearing wastewater;
             •      Chelated metal-bearing wastewater;
             •      General metal-bearing wastewater; and
             •      Metal-bearing sludge.

             Except for F006 hazardous waste, EPA estimated costs for off-site transportation
and treatment/disposal of each waste type in dollars per gallon of waste using averages of cost
data provided in the 1996 MP&M Detailed Survey for off-site disposal of specific wastewater
streams. EPA applied these costs throughout the cost model using the logic in Table 11-14.

11.6.5        Feed Systems and Chemical Dosages

             Feed systems are components of almost every option technology.  EPA developed
three types of cost modules for feed systems: treatment-specific, generic, and low-flow.  EPA
determined dosage, equipment, and other design specifics for  treatment-specific feed systems,
whenever data were available. For feed systems with no specific information available, EPA
developed a generic feed system module, using literature or engineering judgement to select
dosages and equipment.  For feed systems with low-flow treatment systems, EPA developed low-
flow polymer, sodium hydroxide,  sulfuric acid, alum, lime, and ferric sulfate feed modules, with
lower fixed capital and energy costs for flow rates of less than 600 gallons per hour.  EPA also
developed lower energy costs for alum feed systems with flow rates below 350 gallons per
minute. Table 11-15 lists the treatment technologies that use feed systems.
                                         11-49

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                                                      11.0 - Costs of Technology Bases for Regulations
                                   Table 11-14
        Logic Used for Off-Site Treatment and Disposal Cost Estimates
Type of Waste
Painting and paint stripping wastewater
Paint sludge generated by the painting water
curtain centrifugation system
Wastewater bearing oil and grease or other
organic pollutants
Waste oil generated by machining coolant
centrirugation and pasteurization, chemical
emulsion breaking and gravity oil/water
separation, dissolved air flotation, and
ultrafiltration
Waste sludge generated by dissolved air flotation
Hexavalent chromium-bearing wastewater
Cyanide-bearing wastewater
Chelated metal-bearing wastewater
Metal-bearing wastewater
Metal-bearing sludge, generated by the sludge
pressure filtration system and the machining
coolant centrirugation and pasteurization system
Estimated Cost
$2.85 per gallon
$3. 70 per gallon
$1.33 per gallon
$0.86 per gallon
$0.86 per gallon
$3.51 per gallon
$5. 64 per gallon
$1.40 per gallon
$2.00 per gallon
$1.95 per gallon
Data Source
Costs for off-site disposal of solvent-
bearing wastewater as reported in the
1996 MP&M Detailed Survey
Average values reported in the 1996
MP&M Detailed Surveys for hazardous
and nonhazardous waste
Values reported in the 1996 MP&M
Detailed Survey
Values reported in the 1996 MP&M
Detailed Survey
Values reported in the 1996 MP&M
Detailed Survey
Values reported in the 1996 MP&M
Detailed Survey
Values reported in the 1996 MP&M
Detailed Survey
Values reported in the 1996 MP&M
Detailed Survey
Values reported in the 1996 MP&M
Detailed Survey
The value reported in Pollution
Prevention and Control Technology for
Plating Operations (4) for F006
hazardous wastes
            Additional details are provided in Section 6.7.1 of the rulemaking record, DCN
16023.
                                       11-50

-------
                                                          11.0 - Costs of Technology Bases for Regulations
                                     Table 11-15
                 Treatment Technologies That Use Feed Systems
Treatment Technology
Chemical emulsion breaking and gravity oil/water separation
Dissolved air flotation
Batch oil emulsion breaking with gravity flotation
Chemical reduction of hexavalent chromium
Cyanide destruction
Chemical reduction/precipitation of chelated metals
Chemical precipitation
Feed Systems Required
Sulfuric acid
Polymer
Alum
Lime
Ferric sulfate
Polymer
Polymer
Sulfuric acid
Alum
Sulfuric acid
Sodium metabisulfite
Sodium hydroxide
Sulfuric acid
Sodium hypochlorite
Sulfuric acid
Dithiocarbamate
Sulfuric acid
Polymer
Caustic
Sources: Pollution Prevention and Control Technology for Plating Operations (4) and MP&M Sampling Data.

              To determine the required chemical dosage for each technology, the Agency used
either the Pollution Prevention and Control Technology for Plating Operations (4) or chemical
usage data from sampled MP&M sites with the option technology in place. Table 11-16 lists the
chemical dosage used to estimate costs and the source from which the dosage was derived.

              Capital and annual costs from feed systems were not reported individually in cost
model outputs but were added into the overall treatment system capital and annual costs. The
cost model included the capital  and annual costs for the following equipment in the feed system
capital costs:

              •      Raw material storage tank;
              •      Day storage tank with mixer;
              •      Chemical metering pumps;
              •      pH controller; and
              •      Supporting piping and valves.
                                         11-51

-------
                                                         11.0 - Costs of Technology Bases for Regulations
                                     Table 11-16
                          Treatment Dosage Information
Feed system
Polymer feed system
Continuous sodium hydroxide feed system
Continuous hydrated lime feed system
Continuous sulfuric acid feed system
Continuous ferric sulfate feed system
Continuous aluminum sulfate (alum) feed system
Continuous calcium chloride feed system
Chemical Concentration Required
(mg/L)
20
1,685
376
699
74
648
830
Data
Source
(4)
(4)
(4)
(4)
(5)
(5)
(4)
Sources: Pollution Prevention and Control Technology for Plating Operations (4) and MP&M Sampling Data.
11.6.6
Chemical Emulsion Breaking and Gravity Oil/Water Separation
             EPA estimated costs for chemical emulsion breaking and gravity oil/water
separation systems to separate and remove oil and grease and TSS. The Agency assumed that
model sites commingled all oil-bearing wastewater streams prior to treatment. Table 11-12 lists
the unit operations that discharge wastewater streams that feed oil removal treatment units.

             For chemical emulsion breaking systems, the module included capital and annual
costs for the following equipment:

             •      Flow equalization tank;
             •      Two emulsion breaking tanks;
             •      Two mixers;
             •      Sulfuric acid feed system (see Section 11.6.5);
             •      Polymer feed system (see Section 11.6.5);
             •      Alum feed system (see Section 11.6.5);
             •      Sodium hydroxide feed  system (see Section 11.6.5); and
             •      Wastewater pumps.

             Emulsion breaking was followed by oil removal using a coalescent plate
separator.  For oil removal systems, EPA estimated capital and annual costs for the following
equipment:

             •      Feed pumps;
             •      Belt skimmer; and
             •      Oil/water separator.
                                         11-52

-------
                                                           11.0 - Costs of Technology Bases for Regulations

              Direct annual costs included O&M labor and materials, energy costs, raw
materials (e.g., sulfuric acid, alum, polymer, sodium hydroxide), and waste oil disposal costs.
EPA also included costs for off-site reclamation of waste oil.  EPA also estimated waste oil
generation to be 7.1 percent of the influent flow, based on MP&M survey data.

11.6.7        Dissolved Air Flotation

              For the Shipbuilding Dry Dock Subcategory, EPA estimated costs for dissolved
air flotation systems to separate and remove oil and grease, suspended solids, and organic
pollutants.  The Agency assumed that shipbuilding model sites commingled all oil-bearing
wastewater streams prior to treatment.

              The module included capital and annual costs for the following equipment:

              •       Flow equalization tank;

              •       Feed pumps;

              •       Oil/water separator;

              •       Chemical treatment tank;

              •       Lime feed system (see Section 11.6.5);

              •       Ferric sulfate feed system (see Section  11.6.5);

              •       Polymer feed system (see Section 11.6.5);

              •       Dissolved air flotation system with pressure tank and programmable logic
                     controller (PLC);

              •       Oil storage tank; and

              •       Final pH adjustment tank.

              Direct annual costs included O&M labor and materials, energy costs, raw
materials (e.g., hydrated lime, ferric sulfate, polymer), and waste oil and sludge disposal costs.
EPA also estimated costs for off-site reclamation  of the waste oil and sludge.  Hydrated lime and
ferric sulfate flows were added to the discharge flow, while polymer volume was considered
negligible.  EPA estimated generation of waste oil and sludge as 7.1 and 0.03 percent of the
influent flow, respectively, based on the MP&M survey data.  Because dissolved air flotation
systems are not typically used for flow rates of less than 265 gallons per hour (gph), EPA
estimated costs for ultrafiltration oil removal for model sites with flows of less than 265 gph.
                                          11-53

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                                                          11.0 - Costs of Technology Bases for Regulations

11.6.8        Ultrafiltration System for Oil Removal

              EPA estimated costs for ultrafiltration systems to separate and remove oil and
grease, suspended solids, and organic pollutants.  This technology differs from chemical
emulsion breaking with oil/water separation, which was used to develop Option 6 costs (see
11.6.6). The Agency assumed that model sites commingled all oil-bearing wastewater streams
prior to treatment and that flow rates greater than the maximum costed system (406 gallons per
minute) required multiple systems.

              The module included capital and annual costs for the following equipment:

              •      Spiral-wound membrane filtration modules;

              •      Process and chemical tanks;

              •      Steel skid;

              •      Recirculation tank;

              •      Recirculation pump;

              •      Bag filter;

              •      Fix-mounted cleaning system;

              •      Sludge pump; and

              •      Electrical components (pH control/monitoring, temperature control, flow
                    meter, pressure gauges).

              Direct annual costs included O&M labor and materials, energy costs, cleaning
chemicals, membrane replacement, and waste oil disposal costs. EPA estimated costs for off-site
reclamation of waste  oil. EPA estimated waste oil generation as 5.2 percent of the influent flow,
based on MP&M survey data.

11.6.9        Batch Oil Emulsion Breaking with Gravity Flotation

              EPA estimated costs for batch oil emulsion breaking with gravity flotation
systems to separate and remove oil and grease, suspended solids, and organic pollutants.  This
technology differs from chemical emulsion breaking with oil/water separation, which was used to
develop Option 6 costs (see 11.6.6).  Gravity flotation uses a large tank, with oil recovered over
weirs, and is typically seen at large sites such as automotive manufacturing. The Agency
assumed that model sites commingled all oil-bearing wastewater streams prior to treatment.
                                          11-54

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                                                          11.0 - Costs of Technology Bases for Regulations

              Although batch emulsion breaking with gravity flotation is not part of the MP&M
technology options, EPA estimated baseline operating costs and pollutant removals for sites that
had this technology in place at baseline. The module included capital and annual costs for the
following equipment:

              •      Polymer feed system (see Section 11.6.5);
              •      Sulfuric acid feed system (see Section 11.6.5);
              •      Alum feed system (see Section 11.6.5);
              •      Two mechanically cleaning bar screens;
              •      Three batch wastewater treatment tanks;
              •      Two segregated waste tanks;
              •      Three skim and saleable oil storage tanks;
              •      Two oil cooking tanks;
              •      Pumps;
              •      One air compressor;
              •      Six mixers (segregation, saleable oil, and oil cooker tanks); and
              •      Ancillary equipment (pipes and valves, heat trace, controls, and
                    programmable logic controller (PLC)).

              Direct annual costs included O&M labor, energy costs, raw materials (e.g.,
polymer, sulfuric acid, alum), and waste oil disposal costs.  EPA also estimated costs for off-site
reclamation of waste oil. Flows from sulfuric acid and alum were added to the treatment flow,
while the polymer volume was considered negligible. EPA assumed the model sites discharged
treatment effluent to the chemical precipitation and sedimentation system. EPA estimated
generation of waste oil as 2.2 percent of the influent flow, based on MP&M survey data. This
technology is typically used for flow rates of greater than 6,000 gallons per hour, whereas
dissolved air flotation is used for  flow rates of between 265 and 6,000 gallons per hour and
ultrafiltration for oil removal for flow rates of less than 265 gallons per hour.

11.6.10       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. Note that the
sedimentation portion of this treatment is discussed in Section 11.6.14.  The Agency assumed
that model sites commingled all chromium-bearing wastewater streams prior to treatment and
that all chromium in the wastewater was in the hexavalent form.

              The Agency estimated costs for batch treatment for flow rates of less than or
equal to 600 gallons per day and continuous systems for flow rates of greater than 600 gallons
per day.  The module included capital and annual costs for  the following equipment:

              •      Fiberglass reaction tank;
              •      Mixer;
              •      Sulfuric acid feed system;


                                         11-55

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                                                          11.0 - Costs of Technology Bases for Regulations

              •      Sodium metabisulfate feed system;
              •      Flow equalization tank;
              •      Effluent pump; and
              •      pH and oxidation-reduction potential (ORP) meters.

              Direct annual costs included O&M labor and materials, energy costs, and raw
materials (e.g., sulfuric acid, sodium metabisulfite). EPA based flow-dependent costs on the
volume of wastewater from chromium-bearing unit operations flowing into the system, before
treatment chemicals were added to the flow. EPA assumed model sites discharged the treatment
effluent to the chemical precipitation and sedimentation system.

11.6.11       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
model  sites commingled all cyanide-bearing wastewater streams prior to treatment and did not
send cyanide-free wastewater streams to the cyanide destruction system.

              The Agency estimated costs for batch treatment for flow rates of less than or equal
to 600  gallons per day and continuous systems for flow rates of greater than 600 gallons  per day.
The module included capital and annual costs  for the following equipment:

              •      Two reaction tanks (batch treatment uses a single tank, with the second
                    tank operating as a batch-holding tank);

              •      Mixers;

              •      Sodium hydroxide feed system;

              •      Sulfuric acid  feed system;

              •      Sodium hypochlorite feed system;
                                         11-56

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                                                          11.0 - Costs of Technology Bases for Regulations

             •      Effluent pumps; and

             •      pH and ORP meters.

             Direct annual costs included O&M labor and materials, energy costs, and raw
materials (e.g., sodium hydroxide, sulfuric acid, sodium hypochlorite). EPA based flow-
dependent costs on the volume of wastewater from cyanide-bearing unit operation flowing into
the system, before treatment chemicals were added to the flow.  The Agency assumed model sites
discharged the treatment effluent to the chemical precipitation and sedimentation system. EPA
also assumed that all other pollutant concentrations remained unchanged in this treatment unit.

11.6.12      Chemical Reduction/Precipitation of Chelated Metals

             EPA estimated costs for batch and continuous chemical reduction/precipitation of
chelated metal systems to break and precipitate electroless plating complexes (e.g., copper or
nickel complexes) prior to chemical precipitation and sedimentation.  The Agency assumed that
model sites commingled all chelated metal-bearing wastewater streams prior to treatment.

             The Agency estimated costs for batch treatment for flow rates of less than or equal
to 600 gallons per day and continuous systems for flow rates of greater than 600 gallons per day.
The module included capital and annual costs for the following equipment:

             •      Fiberglass reaction tank;
             •      Mixer;
             •      Sulfuric acid feed system;
             •      Dithiocarbamate feed system (see Section 8.4.4);
             •      Flow equalization tank;
             •      Effluent pump; and
             •      pH and ORP meters.

             Direct annual costs included O&M labor and materials, energy costs, and raw
materials (e.g., sulfuric acid, dithiocarbamate). EPA based flow-dependent costs on the volume
of wastewater from chelated metal-bearing unit operations flowing into the system, before
treatment chemicals were added to the flow.  The Agency assumed that model  sites discharged
treatment effluent to the chemical precipitation and sedimentation system. Based on analytical
data for the systems EPA sampled, EPA assumed that concentrations of carbon disulfide and
dithiocarbamate increased across the system.

11.6.13      Chemical Precipitation

             The Agency estimated costs for continuous chemical precipitation systems. EPA
estimated costs for low-flow systems for model sites with influent flow rates of less than or equal
to 300 gallons per hour.  EPA assumed that the model sites commingled all MP&M wastewater
generated for treatment by this technology, except for wastewater from the Oily Wastes,


                                         11-57

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                                                           11.0 - Costs of Technology Bases for Regulations

Shipbuilding Dry Dock, and Railroad Line Maintenance Subcategories. In addition, EPA
assumed that sites would contract for off-site disposal of solvent-bearing wastewater.

              The module included capital and annual costs for the following equipment:

              •       Sulfuric acid feed system (see Section 11.6.5);
              •       Polymer feed system (see Section 11.6.5);
              •       Caustic feed system (see Section 11.6.5);
              •       Equalization tank;
              •       Rapid-mix tank for precipitation;
              •       Flocculation tank;
              •       Final pH-adjustment tank;
              •       System feed pumps; and
              •       Rapid and flocculation mixers.

              Direct annual costs included O&M labor, energy costs, and raw materials (e.g.,
sulfuric acid, polymer, caustic).  The module assumed that the amount of TSS leaving the
chemical precipitation system was equivalent to the sum of influent TSS and the dissolved solids
that are converted to suspended solids when caustic is added to the wastewater. The approach for
calculating suspended solids generated from dissolved solids is documented in Section 6.7.1 of
the rulemaking record, DCN 16363. EPA estimated that the effluent flow rate from this system
equaled the influent flow rate because additional flow from treatment chemical addition was
negligible.  EPA designed the cost model to include recycled water from the sludge thickener and
filter press.  In addition, the Agency assumed that model sites discharged effluent from the
chemical precipitation system to either clarification or microfiltration.

11.6.14       Sedimentation by Slant-Plate Clarifier

              The Agency estimated costs for sedimentation using slant-plate (lamella) clarifier
systems. EPA estimated costs for low-flow systems for model  sites with influent flow rates of
less than or equal to 600 gallons per hour. EPA designed this system to treat effluent from the
chemical precipitation system.

              The module included capital and annual costs for the following equipment:

              •       Slant-plate clarifier; and

              •       One-time training costs for operators to meet MP&M clarifier limits
                     instead of the baseline 40 CFR 433 Metal Finishing effluent guideline
                     limits (see Section 24.6.1, DCN 17906, of the rulemaking record).

              EPA estimated costs associated with achieving long-term average effluent
concentrations for all pollutants treated by chemical precipitation with  clarification (see Section
10.3).  EPA calculated the amount of sludge generated using model-calculated site-specific


                                          11-58

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                                                          11.0 - Costs of Technology Bases for Regulations

influent pollutant concentrations for the commingled wastewater.  The Agency assumed the
sludge was 3 percent solids (5) and was discharged to a sludge-thickening tank (see Section
11.6.17) and that model sites discharged treatment effluent to surface water or a POTW. Direct
annual costs included maintenance labor and materials. EPA included costs for operating labor
in the chemical precipitation module and included costs for pumps in the chemical precipitation
and the  sludge-thickening modules.

11.6.15        Multimedia Filtration

              The Agency estimated costs for a multimedia filter to continuously remove
filterable suspended solids.  The system was designed as a polishing step for effluent from the
clarifier. Although EPA did not include this technology in the MP&M technology options, it
estimated baseline operating costs and pollutant removals for sites that had multimedia filters in
place at baseline.

              The module included capital and annual costs for the following equipment:

              •      Multimedia filter skid;
              •      Holding tank for clarifier effluent (clear well); and
              •      Media filter feed pump.

              Based on data collected during an MP&M sampling episode, the Agency assumed
filter backwash to be 1.2 percent of the influent flow to the chemical precipitation unit and that
model sites discharged filtrate from this system to surface water or a POTW.  Direct annual costs
included O&M labor and energy costs. EPA incorporated waste disposal costs for solids at sites
operating multimedia filters.

11.6.16        Microfiltration for Solids  Removal

              The Agency estimated costs for microfiltration for solids separation, assuming
that flow rates of greater than the maximum costed system (406 gallons per minute) required
multiple systems.

              The module included capital and annual costs for the following equipment:

              •      Tubular membrane filtration modules;
              •      Carbon steel skid;
              •      Recirculation tank;
              •      Recirculation pump;
              •      Air back pulse system;
              •      Cleaning system;
                                          11-59

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                                                          11.0 - Costs of Technology Bases for Regulations

              •      Sludge pump; and
              •      All associated instruments and controls.

              EPA calculated the amount of sludge generated by this system using model-
calculated site-specific influent pollutant concentrations for the commingled wastewater. Based
on data collected during an MP&M sampling episode, the Agency assumed the sludge was 3.2
percent solids and was discharged to a sludge-thickening tank (see Section 11.6.17). EPA
assumed model sites discharged microfiltration effluent to surface water or a POTW. Direct
annual costs included O&M labor and materials (e.g., replacement membranes, cleaning
chemicals) and energy costs.

11.6.17       Sludge Thickening

              The Agency estimated costs for sludge thickening by gravity settling for the
sludge discharged from slant-plate clarifiers and microfilters. EPA assumed the sludge-
thickening system discharged 60 percent of influent flow as sludge, thus increasing the solids
content of the sludge from 3 to  5 percent for clarifier sludges and from 3.2 to 5.3 percent for
microfiltration sludges (6). EPA assumed that the model sites discharge thickened sludge to a
pressure filter for further dewatering (see Section 11.6.18), and that they returned the remaining
40 percent of influent flow (supernatant) to the chemical  precipitation system. The module
included capital and annual costs for the following equipment:

              •      Sludge-thickening unit (package system); and
              •      Clarified water return pump.

              Direct annual costs included O&M labor  and energy costs.

11.6.18       Sludge Pressure Filtration

              The Agency estimated costs for the plate-and-frame filter presses, estimating the
number needed to increase the solids content of the sludge from approximately 5 to 35 percent
(5). The module included capital and annual costs for the following equipment:

              •      Recessed plate or plate-and-frame  filter press; and
              •      Two double-diaphragm sludge pumps.

              Direct annual costs included O&M labor and sludge disposal costs. EPA assumed
model sites contracted for off-site disposal of the denatured sludge (see Section 11.3.2 and Table
11-4). EPA also assumed these sites discharged the filtrate from this system to the chemical
precipitation and sedimentation system.
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                                                          11.0 - Costs of Technology Bases for Regulations

11.7         References

1.            RS Means Building Construction Cost Data, 56th Annual Edition.  1998, page
             594. Historical Cost Indexes.

2.            Chemical Marketing Reporter. December 1997.

3.            U.S. Bureau of Labor Statistics. Monthly Labor Review. 1997.

4.            Cushnie, George C., CAI Engineering (prepared for NCMS/NAMF). Pollution
             Prevention and Control Technology for Plating Operations.

5.            Cherry, Kenneth F.  Plating Waste Treatment. Chapters. Ann Arbor Sciences
             Publishers, Inc., Ann Arbor, MI, 1982.

6.            Eckenfelder, W. Wesley. Principals of Water Quality Management. Chapter 11.
             CBI Publishing Company, 1980.
                                         11-61

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                                     11.0 - Costs of Technology Bases for Regulations
                    Industrial process
                   wastewater streams
                     current o.
                     being analyzed
                       In-process
                      flow control
                      and pollution
                       prevention
                      End-of-pipe
                       treatment
                  Discharge to surface
                     water or POTW
aSee Section 9.0 for descriptions of the 10 technology options.


Figure 11-1. Relationship Between In-Process and End-
          of-Pipe Technologies and Practices
                    11-62

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                                                   11.0 - Costs of Technology Bases for Regulations
                                Individual
                           process wastewater
                                streams
     Is flow
    reduction
 applicable to
                      contain paint or
                        machining
                         coolant?
                                  rinse
                                stream?
                                      Combine
                                        paint
                                       curtain
                                    wastewater
                                      streams
                         Combine
                        machining
                          coolant
                        wastewater
                         streams
Countercurrent
cascade rinse
/Discharge^.
I to end-of-pipe 1
I   treatment   I
\systerri/
Centrifugation
      of
   painting
    water
   curtains
                                  f  Discharge
                                    to end-of-pipe
                                  I   treatment   J
                                                         Centrifugation
                                                              and
                                                         pasteurization
                                                          of machining
                                                           coolants
                     / Discharge^v
                     I  to end-of-pipe I
                     I   treatment   I
        Figure 11.2. Components of Total Capital Investments
                                 11-63

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                                                                11.0 - Costs of Technology Bases for Regulations
                              Wastewater streams from
                               individual processes or
                                 in-process controls
                                      oes the
                                    wastewater
                                 contain chromium
                                 cyanide, chelated
                                    metal, oil, or
                                     solvent?
                                                                                      solvent-bearing
                                                    Chemical emulsion
                                                        breaking
                                                     (polymer, alum,
                                                       sulfuric acid,
                                                         caustic)
                                                                                        Contract
                                                                                        for off-site
                                                                                        treatment
                                                                                       and disposal
chelated metals
                                        Oil
                                      reclaim/
                                      disposal
                                                                      Discharge to
                                                                     surface water
                                                                       or POTW
                                            Contract haul
                                             for off-site
                                             disposal
  Figure 11-3. Logic Used to Apply End-of-Pipe Technologies and Practices for the Following
Subcategories: General Metals, Metal Finishing Job Shops, Non-Chromium Anodizing, Printed
                         Wiring Board, and Steel Forming and Finishing
                                              11-64

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                                                   11.0 - Costs of Technology Bases for Regulations
                         Wastewater streams from
                          individual processes or
                            in-process controls
Railroad Line Maintenance or Oily Wastes  /subcateaorv\Shipbuild'n9 Dl7 D°Ck
                                is the site
                                  in?
                     Is
                  the option
                   5 or 6 or
                   7 or 8?a
  Is the
 option
7 or 8 or
9or10?a
 Chemical emulsion
 breaking (polymer,
 alum, sulfuric acid)
           floatation (lime
                                                Oil
                                           H  reclaim/
                                              disposal
                              Discharge to
                              surface water
                                orPOTW
          3 See Section 9.0 for descriptions of the 10 technology options.


  Figure 11-4. Logic Used to Apply End-of-Pipe Technologies
  and Practices for the Following Subcategories: Oily Wastes,
    Railroad Line Maintenance, and Shipbuilding Dry Dock
                                11-65

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                                                                                                11.0 - Costs of Technology Bases for Regulations
ON
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Figure 11-5.  Example Treatment Facility for General Metals Subcategory Direct Discharger

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                                                          12.0 - Pollutant Loading and Reduction Estimates

12.0         POLLUTANT LOADING AND REDUCTION ESTIMATES

             This section describes EPA's approach for modeling the MP&M industry annual
pollutant loadings and removals for each technology option described in Section 9.0. In general,
this approach consists of three major steps:

             1.     Estimate baseline pollutant loading from each MP&M model site.
                    Wastewater discharged from MP&M unit operations goes to either on-site
                    treatment, publicly owned treatment works (POTWs), or directly to
                    surface waters. EPA used survey data from each model site to determine
                    the destination of each waste stream. EPA estimated discharged pollutant
                    concentrations from:  EPA sampling data, industry-supplied data, and
                    existing limitations. EPA estimated loadings by multiplying the
                    discharged pollutant concentrations by the discharged flow.  The baseline
                    pollutant loading refers to the total amount of pollutants discharged from
                    the model site to surface waters or POTWs for the base year of the survey.

             2.     Estimate baseline pollutant loadings for the MP&M industry.  EPA
                    multiplied the site-specific baseline wastewater loadings by the
                    corresponding statistically derived weighting factors (see Section 3.0) for
                    each model site. EPA summed the weighted loadings across all sites to
                    estimate industry-wide baseline wastewater pollutant loadings.

             3.     Estimate option-specific pollutant loadings and removals for the MP&M
                    industry.  The option-specific pollutant loadings represent the total
                    industry pollutant loadings in MP&M wastewater that would be
                    discharged to surface water or POTWs after complying with a particular
                    regulatory option.

             Key terms for pollutant loadings and removals are defined below:

             •      Model sites - Facilities used in the EPA Costs & Loadings Model to
                    represent the industry nationally.  These facilities responded in the MP&M
                    detailed survey that they discharge MP&M wastewater.

             •      Long-term average - Average pollutant concentrations achieved over a
                    period of time by a facility, subcategory, or technology option.

             •      Baseline  concentration - Pollutant concentration (milligrams per liter
                    (mg/L)) in wastewater currently discharged to surface water or a POTW.
                    If the facility has wastewater treatment in place, the baseline concentration
                    is the pollutant concentration in wastewater discharged from final
                    treatment.  If the facility does not have treatment in place, the baseline
                    concentration is the commingled concentration of all unit operation
                    wastewater discharged.

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                                                          12.0 - Pollutant Loading and Reduction Estimates

              •      Baseline loadings - Modeled pollutant loadings, in pounds per year
                    (Ibs/yr), in MP&M wastewater currently being discharged to surface water
                    or to POTWs for the base year of the model site's survey.  These loadings
                    reflect wastewater treatment in place at model sites in the year 1996.

              •      Option loadings - Also referred to as post-compliance loadings.  Pollutant
                    loadings, in Ibs/yr, in MP&M wastewater that would be discharged to
                    surface water or to POTWs after complying with a regulatory option. EPA
                    calculated the loadings assuming that all MP&M facilities would achieve
                    long-term average effluent pollutant concentrations associated with the
                    technology options.

              •      Pollutant reductions - The difference between baseline loadings and option
                    loadings for each regulatory option.

              •      Weighting factor - Statistically derived values for each model site used to
                    reflect all facilities in the MP&M industry.  (See Section 10.0, DCN 16118
                    of the rulemaking record). EPA multiplied the baseline or option loadings
                    for each model site by its corresponding weighting factor to estimate
                    industry-wide baseline or option loadings.

              •      Toxic pound-equivalents - Pollutant loadings, in pound-equivalents per
                    year (PE/yr), in MP&M wastewater. A pound-equivalent (PE) is a pound
                    of pollutant weighted for its toxicity to human and aquatic life.

              Unless specified otherwise, EPA estimated baseline pollutant loadings and
reductions for all pollutants identified in Section 7.0 as pollutants of concern. EPA used data
from several sources to estimate pollutant loadings and reductions, including data from EPA
sampling episodes, the existing 40 CFR 413 and 433 regulations, EPA's Permit Compliance
System (PCS) database, pretreatment coordinators, states, and industry.  See Section 3.0 for
additional discussion on EPA's data collection efforts.

              Note that all tables appear at the end of this section.

12.1          Estimation of Unit Operation Wastewater Pollutant Concentrations

              EPA used sampling data and industry-supplied data (included in Sections 5.0 and
15.0 in the rulemaking record) to estimate subcategory-specific wastewater pollutant
concentrations for each of the MP&M unit operations that generate wastewater at MP&M model
sites.

12.1.1         Unit Operation Wastewater Data Collection

              EPA's "unit operations database" comprises EPA sampling data and industry-
supplied data.  EPA collected unit operations wastewater discharged from 56 sites for 96 unit

                                           12-2

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                                                          12.0 - Pollutant Loading and Reduction Estimates

operations. Industry supplied EPA with wastewater data for 15 unit operations.  Throughout this
section, the terms "sampling point" and "sample" refer to the following:

              •      Sampling point - The physical location at which samples are collected.
                    Example sampling points include a wastewater treatment influent stream,
                    an electroplating bath, or a cleaning rinse. A sampling point captures the
                    wastewater characteristics of a specific unit operation or a group of unit
                    operations.

              •      Sample - The unique volume of wastewater collected for analysis at a
                    sampling point. A sample can include several different aliquots collected
                    for analysis of multiple parameters.  Each sample represents a unique
                    period of time.  EPA typically collected multiple samples from sampling
                    points that represented flowing waste streams (e.g., wastewater treatment
                    systems, rinses).

12.1.2         Calculation of Pollutant Concentrations for Each Unit Operation for Each
              Sampling Point from EPA or Industry-Supplied Sampling Data

              EPA collected both grab and composite samples to characterize MP&M unit
operations. EPA generally collected grab samples for nonflowing streams where the pollutant
concentrations were not expected to vary  significantly over the sampling period. EPA generally
collected composite samples (typically 24-hour composites) for flowing streams.  For oil and
grease, EPA collected a series of grab samples as specified by the analytical method. In some
cases, EPA had to mathematically aggregate two or more samples to obtain a single value that
could be used in calculations to represent a single waste stream. This occurred with field
duplicates and grab samples collected over time.  For each sample point, EPA aggregated field
duplicates first, grab samples second, and multiple-day samples third. In cases where the
sampled pollutants were not detected in the wastewater, EPA used the sample-specific detection
limit as the pollutant concentration.  EPA calculated pollutant concentrations for each sampling
point using the following approach:

              •      Average the duplicate sample concentrations. As discussed in Section 3.0,
                    EPA collected duplicate samples at many sampling points as a quality
                    control measure. Industry-supplied data submitted  with comments on the
                    MP&M proposal also contained duplicate samples. Where duplicate
                    samples were collected at a sampling point, EPA averaged the
                    concentrations of the two samples to develop a single pollutant profile for
                    the sampling point for that 24-hour period.

              •      Average the grab sample aliquot concentrations. EPA averaged the
                    concentrations of all grab sample aliquot fractions (i.e., for oil and grease)
                    collected during a 24-hour period in order to estimate a representative 24-
                    hour composite for that parameter.
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                                                           12.0 - Pollutant Loading and Reduction Estimates

              •      Average multiple sample concentrations for each sampling point. For
                    flowing wastewater streams (e.g., rinses), EPA and industry typically
                    collected multiple samples at a single sample point to account for
                    variability over time of the discharges from these streams.  EPA averaged
                    the concentrations of the composite or grab samples collected on each day
                    at the same sampling point. For example, if EPA collected three one-day
                    composite samples of an acid treatment rinse at the same sampling point, it
                    averaged the concentrations of each pollutant on each of the three days to
                    develop a single pollutant profile for the sampling point for that episode.

12.1.3        Estimation of Pollutant Concentrations for Each Subcategory and Unit
              Operation

              EPA estimated pollutant concentrations for each unit operation performed in  a
given subcategory (as reported in the MP&M detailed surveys).  For example, EPA estimated
pollutant concentrations for UP-4 (acid treatment without chromium) separately for sites in the
General Metals Subcategory and for sites in the Metal Finishing Job Shops Subcategory.  For
electroplating and electroless  plating operations, EPA estimated the pollutant concentration(s) of
the applied metal(s) separately from other bath constituents to account for the dependancy of
these operations on high concentrations of the applied metal(s).  EPA used the following steps to
estimate the subcategory-specific unit operation wastewater pollutant concentrations at model
MP&M sites:

              1.     Identified, for each subcategory, all unit operations reported in the detailed
                    surveys (see Section 12.1.3.1);

              2.     Estimated pollutant concentrations for each unit operation in a given
                    subcategory (see Section 12.1.3.2);

              3.     Estimated an applied metal concentration in the bath and in the rinse for
                    each electroplating and electroless plating operation for each subcategory
                    (see Section 12.1.3.3); and

              4.     Modeled pollutant concentrations for each model site unit operation (see
                    Section 12.1.3.4).

These steps are described in the following subsections.

12.1.3.1       Identification of Unit Operations Reported in the Detailed Surveys

              EPA queried the MP&M detailed survey database to identify all unit operations
discharging wastewater, as well as all types of electroplating and electroless plating operations
(defined by applied metal).
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                                                          12.0 - Pollutant Loading and Reduction Estimates

12.1.3.2       Estimation of Wastewater Pollutant Concentrations for Each Unit
              Operation/Subcategory Combination

              For each subcategory, EPA calculated the average wastewater pollutant
concentrations for each unit operation. For example, EPA averaged the wastewater pollutant
concentrations for all acid cleaning operations (using the wastewater pollutant concentrations
calculated at each sampling point) at facilities in the General Metals Subcategory. EPA also
separately estimated wastewater pollutant concentrations for unit operations for the "zinc plater"
segments of the Metal Finishing Job Shops and General Metals Subcategories.

              Additionally, EPA combined the sampling data for all metal-bearing
subcategories (with the exception of data from printed wiring board facilities1) and calculated the
average wastewater pollutant concentrations for each unit operation. EPA did the same for all
oil-bearing subcategories. EPA used the average unit operation concentrations calculated for
metal-bearing subcategories and oil-bearing subcategories to estimate pollutant concentrations
from unit operations in subcategories with no unit operation concentration data.

              Based on comments received on the MP&M proposed rule, EPA modified the
calculation of unit operation wastewater pollutant concentrations for the following pollutants:

              •       Cyanide.  EPA set the cyanide pollutant concentration equal to zero for all
                     non-cyanide-bearing unit operation wastewaters.  (EPA sampling data
                     included incidental cyanide concentrations for non-cyanide-bearing unit
                     operations due to drag-out or unspecified sources.)

              •       Total Sulfide.  EPA estimated wastewater pollutant concentrations for total
                     sulfide using all results from Phase I and U sampling (Method 376.1) and
                     an average of the results from Methods 376.2 and 4500-S2E from Phase
                     in sampling. EPA used all three analytical methods (376.1, 376.2, and
                     4500-S2E) to measure total sulfide in Phase HI sampling (i.e., post-
                     proposal sampling); however, EPA did not use sampling data from
                     Method 376.1 from Phase HI due to possible interferences.

              •       Oil and Grease. EPA estimated wastewater pollutant concentrations for
                     oil and grease using all Phase II and in data, but included Phase I data only
                     in cases where no Phase U or in data were available for that unit operation
                     in the Oily Wastes, Railroad Line Maintenance, and Shipbuilding Dry
                     Dock Subcategories.  EPA used a different analytical method to measure
                     for oil and grease during Phase I sampling than during Phase U and HI
                     sampling.  EPA used Method 413.2 during Phase I sampling (a freon-
                     extractable method).  EPA used Method 1664 during Phase II and Phase
                     in sampling (measures oil and grease as hexane extractable material).
'EPA omitted data from the Printed Wiring Board Subcategory due to the high concentration of specific metals (i.e.,
copper) common to primarily the printed wiring board industry.

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                                                          12.0 - Pollutant Loading and Reduction Estimates

              •      Sodium, Calcium, and Total Dissolved Solids.  EPA set the wastewater
                    pollutant concentrations for these pollutants equal to zero for all unit
                    operation wastewaters in all subcategories.  EPA set the pollutant
                    removals for sodium and calcium equal to zero in response to Phase I
                    comments on the wide use of these two treatment chemicals, which results
                    in elevated removals estimates. EPA set the loads removals for total
                    dissolved solids (IDS) equal to zero because many treatment chemicals
                    also elevate TDS concentrations.

              Based on comments received on the MP&M proposed rule, EPA modified the
calculation of unit operation wastewater pollutant concentrations for the following specific cases:

              •      Testing. EPA used data from radiator pressure testing operations to
                    estimate unit operation wastewater pollutant concentrations for all testing
                    unit operations at model sites in the oil-bearing wastewater subcategories
                    and hydraulic testing unit operations in the metal-bearing wastewater
                    subcategories. EPA used dye penetrant testing data to estimate wastewater
                    pollutant concentrations in all other types of testing in the metal-bearing
                    wastewater subcategories.  EPA did not include the other EPA-sampled
                    testing data (from alpha-case detection testing and engine performance
                    testing coolant operations) based on the unique composition of wastewater
                    for these site-specific operations.

              •      Unit Operations with a Greater Rinse Concentration  than Bath
                    Concentration.  After averaging sampling data across samples  for a
                    particular sampling point, EPA found instances where the modeled bath
                    had a lower concentration than  for the same pollutant in the associated
                    rinse. In these cases, EPA set the bath wastewater pollutant concentration
                    equal to the rinse wastewater pollutant concentration.

              Based on comments received on the MP&M proposed rule, EPA modified the
calculation of unit operation wastewater pollutant concentrations for certain pollutants in the
Non-Chromium Anodizing Subcategory:

              •      Chromium, Hexavalent Chromium, Lead, and Cadmium. EPA set the
                    wastewater pollutant concentrations for these pollutants equal to zero for
                    all unit operation wastewaters in the Non-Chromium Anodizing
                    Subcategory. EPA defined the  Non-Chromium Anodizing Subcategory as
                    sites that have no chromium present in any operation on site. Therefore,
                    EPA did not expect chromium or hexavalent chromium to be present at
                    non-chromium anodizing facilities. EPA also did not expect lead or
                    cadmium to be used in unit operations at non-chromium anodizing
                    facilities based on the metal types processed by this Subcategory.
                                          12-6

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                                                           12.0 - Pollutant Loading and Reduction Estimates

For further details, refer to the memorandum entitled "MP&M Pollutant Loadings Methodology
Changes from Proposal" located in the rulemaking record (Section 16.7, DCN 16764).

12.1.3.3       Estimation of Applied Metal Concentrations Using Available Analytical Data

              While the pollutant concentrations in many MP&M unit operations are somewhat
dependent on the type of metal processed, pollutant concentrations are heavily dependent on the
applied metal in the electroplating and electroless plating operations. For example, chromium
electroplating operations and rinses contain higher concentrations of chromium than other
metals, while electroless nickel plating operations  and rinses contain higher concentrations of
nickel  than other metals. EPA estimated the pollutant concentrations of the plated metal(s),
referred to as "applied" metals, separately from other constituents in the bath and rinse to account
for the dependency of the pollutant concentrations in these operations and rinses on these
metal(s). When developing the model pollutant concentrations for these two unit operations,
EPA designated the metal(s) applied to the surface of the product as the  "applied metals" to
distinguish them from other nonplated metals in the process bath. EPA also designated these
metals that wash off the product during the process rinse as the "applied metals" in the rinse.

              To more adequately represent the metals concentrations in the wastewater from
electroplating and electroless plating operations, EPA used a different approach for applied
metals and other plating bath constituents in these  operations.  Due to budget constraints, EPA
did not obtain sampling data for every type of plating solution and rinse  reported in the detailed
surveys and was therefore unable to estimate separately the pollutant concentrations for each type
of plating.  EPA modeled the pollutant concentrations in electroplating and electroless plating
solutions using the following approach:

              1.     EPA calculated the total applied metal concentrations for each plating bath
                     for which EPA had collected data.  If a sampling point had two applied
                     metals (e.g., zinc and cobalt), the two pollutant concentrations were
                     summed to get a total applied metal concentration. If a sampling point had
                     one applied metal, the concentration for that metal was the total applied
                     metal  concentration.

              2.     For each subcategory, EPA  calculated the median total  applied metal
                     concentration for all plating baths for which EPA had sampling data. EPA
                     calculated these median concentrations separately for electroplating and
                     electroless plating baths. EPA then modeled the total metal concentration
                     in the  bath at the model site as the median concentration of total metals for
                     which EPA had data. Note that the Agency had sufficient data to estimate
                     the total applied metal concentration on a subcategory-specific basis, but
                     not on a pollutant-specific basis.  For subcategories with no available
                     applied metal data, EPA used the median of all total applied metal
                     concentration data across all subcategories.
                                           12-7

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                                                           12.0 - Pollutant Loading and Reduction Estimates

              3.      EPA calculated the average concentration for all nonapplied pollutants
                     across the plating baths (separating electroplating from electroless plating
                     baths).  For example, EPA calculated the cadmium concentration in all
                     baths other than cadmium electroplating baths.  EPA then modeled the
                     concentration of the nonapplied pollutants as the average concentration for
                     the pollutant across the plating baths.

              EPA followed the same approach for estimating pollutant concentrations in
electroplating and electroless plating unit operation rinses.  For further detail, refer to the
memorandum entitled "MP&M Pollutant Loadings Data Transfer for Base/Applied Metals"
located in the rulemaking record (Section 16.7, DCN  16763).

12.1.3.4       Modeling of Pollutant Concentrations for Each Model Site Unit Operation

              To estimate the pollutant concentrations for each model site unit operation, EPA
first identified the unit operations performed by the model sites in each subcategory. For unit
operations for which it had  collected pollutant concentration data, EPA modeled the wastewater
pollutant concentrations using the corresponding unit operation average wastewater pollutant
concentrations calculated from sampling data for that unit operation in the same subcategory.
For example, EPA calculated the average concentrations for all pollutants of concern identified
in alkaline cleaning operations in the General Metals Subcategory, and applied these average
concentrations to all alkaline cleaning operations reported in the surveys for this subcategory.

              When EPA did not have pollutant concentration data for a unit operation within a
subcategory, EPA transferred pollutant concentrations from unit operations expected to have
similar wastewater characteristics, based on process considerations. Process considerations
include the following: 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,
rinse water); and typical bath additives (e.g., acids, organic solvents, metal salts).  EPA
transferred available pollutant concentration data to the model sites using the following
hierarchy:

              1.      If EPA sampled the same unit operation bath (or rinse) at facilities in more
                     than  one subcategory, including the same subcategory as the model site,
                     the Agency used available analytical data for the same operation in the
                     same subcategory to estimate wastewater pollutant concentrations for the
                     model site unit operation. For example, if available analytical data for a
                     unit operation exist for both the General Metals and the Metal Finishing
                     Job Shops Subcategories, EPA transferred data from only the General
                     Metals Subcategory to model the wastewater pollutant concentrations for
                     the same unit operation at a model site in the General Metals Subcategory.

              2.      If EPA sampled the same unit operation bath (or rinse) at facilities in only
                     one MP&M subcategory, even if it is a different subcategory than that of
                     the model site, the Agency transferred these data to the same unit

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                     operation bath (or rinse) at model sites. For example, if available
                     analytical data for a unit operation exist only for the General Metals
                     Subcategory, EPA transferred these data to model the wastewater pollutant
                     concentrations for the same unit operation at a model site in any other
                     subcategory.

              3.      If EPA did not have unit operation sampling data from a site in
                     Subcategory A, then EPA used unit operation sampling data from a site in
                     a similar subcategory (e.g., if Subcategory A is a metal-bearing
                     subcategory, data from another metal-bearing subcategory was used).  The
                     Agency used available analytical data for the same operation in similar
                     subcategories to estimate wastewater pollutant concentrations  for the
                     model site unit operation.  For example, if available analytical  data for a
                     unit operation bath (or rinse) exist from both metal-bearing wastewater
                     facilities and oil-bearing wastewater facilities, EPA used the following
                     approach. If the model site is designated as one of the metal-bearing
                     wastewater  subcategories, only available  analytical data from other
                     metal-bearing wastewater subcategorized facilities were used to estimate
                     wastewater  pollutant concentrations. EPA used the same approach for
                     oil-bearing wastewater subcategories.

              4.      If EPA did not sample a unit operation bath (or rinse) that is the same as
                     the unit operation at a model site, the Agency used the available analytical
                     data for a unit operation bath (or rinse) that has similar wastewater
                     characteristics, but are within the same subcategory, to estimate
                     wastewater  pollutant concentrations for the model site unit operation.  Due
                     to budget constraints, EPA did not collect data for 22 baths and 24 rinses,
                     representing approximately 8.3 percent of the total MP&M discharge flow
                     rate.  The basis for these estimates are discussed in the memorandum
                     entitled "Data Transfers Between Unit Operations" located in  the
                     rulemaking  record (Section 16.7, DCN 17767).

              Supporting documentation for all data transfers of unit operation pollutant
concentrations is contained in Section 16.7 of the MP&M rulemaking record.

12.2          Estimation of Industry Baseline Pollutant Loadings

              Industry baseline wastewater pollutant loadings are modeled pollutant loadings in
MP&M wastewater discharged to  surface waters or to POTWs for the base year of the detailed
surveys, supplemented by additional site information provided to EPA. These  loadings reflect
wastewater treatment in place at model sites in the year 1996. EPA estimated baseline pollutant
loadings using the effluent pollutant concentrations, unit operation flows provided in the
questionnaire (as described in Section 11.2.2), and effluent flows from treatment (estimated by
the EPA Costs & Loadings Model as described in Section 11.3.3).  EPA estimated the baseline
pollutant loadings using the approaches described in this subsection.

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12.2.1         Estimation of Baseline Pollutant Concentrations from Sites in the Metal-
              Bearing Subcategories

              For the final rule, EPA revised its methodology for estimating baseline pollutant
concentrations in metal-bearing subcategories. The final methodology varies depending on
whether or not the stream is treated or untreated and also by its current regulatory status.

12.2.1.1       Estimation of Effluent Pollutant Concentrations for Untreated Streams

              EPA used the following steps to estimate the wastewater pollutant concentrations
for each pollutant of concern (POC) in wastewater discharged from model sites without
treatment:

              1.     Estimated wastewater pollutant concentrations for each unit operation
                    that discharges wastewater from the site without treatment. EPA
                    estimated unit operation wastewater pollutant concentrations using the
                    methodology described in Section 12.1. EPA notes that the unit
                    operations data were significantly revised between the proposal and the
                    Notice of Data Availability (NOD A), and have been revised further based
                    on comments on the NODA (see DCN 16764 in Section 16.7 of the
                    rulemaking record).

              2.     Incorporated limits on wastewater discharged from sites regulated by 40
                    CFR 413 only (Baseline for the 413 to  433  Upgrade Analysis). For the
                    final rule, in response to comments, EPA accounted for sites that are
                    currently regulated by and complying with Part 413. For streams not
                    currently receiving treatment at model  sites subject to Part 413, but not
                    Part 433, EPA assumed the sites achieved the monthly average limitation
                    for Part 413 regulated parameters (i.e., set the wastewater pollutant
                    concentrations equal to the Part 413 limits (as opposed to achieving the
                    long-term average (LTA) concentration)). EPA noted that the Part 413
                    limit for cyanide is different for small platers than for large platers.  For
                    parameters not regulated by Part 413, EPA  estimated wastewater pollutant
                    concentrations from the unit operations data.  MP&M facilities covered
                    under Part 413 only include some, but not all, indirect dischargers in the
                    Printed Wiring Board, Metal Finishing Job  Shops, and General Metals
                    Subcategories.  EPA conducted a unique analysis to determine the costs
                    and loads associated with the upgrade of facilities regulated under Part 413
                    to meet the Part 433 limits. EPA used  the methodology described in this
                    section to estimate baseline pollutant concentrations of untreated streams
                    for this analysis.

              3.     Incorporated limits on wastewater discharged from sites regulated by 40
                    CFR 433 (or Parts 413 and 433). For the final rule, in response to
                    comments, EPA accounted for sites that are currently regulated by and

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                                                         12.0 - Pollutant Loading and Reduction Estimates

                    complying with 40 CFR 413 and 433, or 433 only.  EPA assumed the
                    untreated streams achieved the monthly average limitation for Part 433
                    regulated parameters (i.e., set the wastewater pollutant concentrations
                    equal to the Part 433 limits (as opposed to achieving the LTA
                    concentration)). For parameters not regulated by Part 433, EPA estimated
                    wastewater pollutant concentrations from the unit operations data. MP&M
                    facilities covered under Part 433 include all direct and some indirect
                    dischargers in the Printed Wiring Board and Metal Finishing Job Shops
                    Subcategories, and some direct and indirect dischargers in the General
                    Metals and Non-Chromium Anodizing Subcategories.

             4.     Incorporated limits on wastewater discharged from sites not regulated by
                    40 CFR 413 or 433 (Baseline for the Local Limits to 433 Upgrade
                    Analysis).  For the final rule, in response to comments, EPA also
                    incorporated changes to take into account the compliance of indirect
                    dischargers in the General Metals Subcategory, not currently regulated by
                    Parts 413 or 433, with local limits. Although EPA could not obtain  actual
                    local limits for all facilities, EPA gathered local limits data from 213
                    POTWs in seven EPA Regions to develop national median local limit
                    values, (see DCN 17844 of the rulemaking record for  a list of the data and
                    the median value for each parameter). EPA assumed the untreated streams
                    achieved the national median local limit for all parameters regulated by
                    Part  433 in untreated streams.  For parameters not regulated by Part  433,
                    EPA estimated wastewater pollutant concentrations from the unit
                    operations data. EPA conducted a unique analysis to determine the costs
                    and loads associated with the upgrade of facilities not regulated under
                    Parts 413 or 433 to meet the Part 433 limits. EPA used the methodology
                    described in this section to estimate baseline pollutant concentrations of
                    untreated streams for this analysis.

             5.     Estimated commingled wastewater concentrations for all untreated
                    streams. EPA combined the wastewater from all unit operation discharges
                    that are not sent through treatment. EPA calculated the commingled
                    concentration of each POC in the combined MP&M wastewater based on
                    pollutant concentrations and flow rates of each stream.

12.2.1.2      Estimation  of Effluent Pollutant Concentrations for Treated Streams

             EPA used the Costs & Loadings Model (see Section 11.0) to estimate the
pollutant concentrations in  wastewater discharged from the treatment technology at each model
site.  EPA used the following steps to estimate the wastewater pollutant concentrations for each
POC in treated discharged wastewater:

             1.     Estimated wastewater pollutant concentrations for each unit operation
                    that discharges wastewater to treatment. EPA estimated unit operation

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                    wastewater pollutant concentrations using the methodology described in
                    Section 12.1.  EPA notes that the unit operations data were significantly
                    revised between the proposal and the NOD A, and have been revised
                    further based on comments on the NODA (see DCN 16764 in Section 16.7
                    of the rulemaking record).

             2.     Estimated wastewater concentrations in influent to treatment (commingled
                    wastewater concentrations for all treated streams). EPA combined the
                    wastewater from all unit operations that discharge to treatment. EPA
                    calculated the commingled (treatment influent) concentration of each POC
                    in the combined MP&M wastewater, based on pollutant concentrations
                    and flow rates of each stream. The treatment influent concentrations are
                    required to estimate baseline costs (see  Section 11.0).

             3.     Estimated wastewater concentrations in effluent from treatment. EPA
                    used the Costs & Loadings Model (see Section 11.0) to estimate the
                    pollutant concentrations in wastewater discharged from each model site
                    wastewater treatment unit.  The following summarizes the pollutant
                    concentrations for the various treatment technologies reported for the
                    metal-bearing subcategories.

                    •      Treatment Equivalent to the Metal Finishing (40 CFR 433) Best
                           Available Treatment (BAT). EPA assumed that all streams that
                           undergo treatment equivalent2 to the Metal Finishing (40 CFR 433)
                           BAT technology basis are treated to achieve the LTAs promulgated
                           at 40 CFR 433 for those parameters regulated under Part 433  (433
                           parameters). EPA assumed that parameters not regulated under
                           Part 433 (non-433 parameters) are treated to achieve the LTAs
                           based on MP&M BAT (Option 2) sampled sites.

                    •      Microfiltration for Solids Removal Technology. For streams
                           treated by a membrane system, EPA assumed that the membrane
                           technology could treat to a lower concentration than the 433 LTAs.
                           Therefore, EPA assumed the membrane technology could achieve
                           the lower of the LTAs calculated based on MP&M sampled sites
                           using membrane technology or the 433 LTAs.

                    •      Chemical Reduction of ChelatedMetals.  For streams treated by a
                           chelation breaking system, EPA assumed the reduction of chelated
                           metals to the elemental state. The concentrations of carbon
                           disulfide and dithiocarbamate (DTC) increase in the chelation
                           breaking module to account for addition of treatment chemicals.
2Refer to Table 11-5 for treatment technologies considered equivalent to chemical precipitation and sedimentation.

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                                            12.0 - Pollutant Loading and Reduction Estimates

       •      Oil Treatment (Chemical Emulsion Breaking and Oil/Water
             Separation) and Batch Oil Emulsion Breaking with Gravity
             Flotation. EPA assumed oil treatment and batch oil emulsion
             breaking technologies could achieve the LTAs calculated based on
             MP&M sampled sites using chemical emulsion breaking with
             gravity oil/water separation.

       •      Ultrafiltration (for Oil Removal).  EPA assumed ultrafiltration
             technologies could achieve the LTAs calculated based on MP&M
             sampled sites using ultrafiltration (for oil removal).

       •      Dissolved Air Flotation (DAF). EPA assumed DAF technology
             could achieve the 433 limits for all 433 parameters.  For non-433
             parameters, EPA assumed DAF technology could achieve the
             LTAs calculated based on MP&M sampled sites using DAF
             technology.

       •      Cyanide Destruction and Ion Exchange. EPA assumed cyanide
             destruction and  ion exchange technologies could reduce the
             amount of cyanide in cyanide-bearing wastewater. EPA assumed
             total cyanide, amenable cyanide, and weak-acid dissociable
             cyanide are reduced to the LTAs calculated based on MP&M
             sampled sites using cyanide destruction. The concentration of
             chloroform increases in the cyanide destruction module to  account
             for the reduction process.

       •      Chemical Reduction of Hexavalent Chromium.  EPA assumed
             hexavalent chromium reduction could reduce the amount of
             hexavalent chromium to achieve the LTA calculated based on
             MP&M sampled sites using hexavalent chromium reduction. The
             concentration of trivalent chromium increases in the hexavalent
             chromium reduction module to account for the conversion process.

       Note that if the treated effluent concentration for a pollutant was more than
       its corresponding treatment influent concentration (obtained in step 2
       above), EPA retained the treatment influent concentration to estimate the
       baseline  concentration for that pollutant.

4.      Incorporated limits on wastewater discharged from sites regulated by 40
       CFR 413 only (Baseline for the 413 to 433  Upgrade Analysis). For the
       final rule, in response to comments, EPA accounted for sites that are
       currently regulated by and complying with Part 413 only. For streams
       receiving treatment at model sites subject to Part 413, but not Part 433,
       EPA assumed the sites  achieved the LTAs for Part 413 regulated
       parameters (i.e., set the wastewater pollutant concentrations equal  to the

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                    Part 413 LTA concentration). EPA noted that 40 CFR 413 only sets
                    limitations on lead, cadmium, and cyanide for small platers.  EPA assumed
                    small platers achieved the monthly limit average for those additional
                    parameters regulated by Part 413 for large platers. For parameters not
                    regulated by Part 413, EPA assumed sites achieve the baseline pollutant
                    concentrations for the treatment technology. MP&M  facilities covered
                    under Part 413 only include some indirect dischargers in the Printed
                    Wiring Board, Metal Finishing Job Shops, and General Metals
                    Subcategories. EPA conducted a unique analysis to determine the costs
                    and loads  associated with the upgrade of facilities regulated under Part 413
                    to meet the Part 433 limits.  EPA used the methodology described in this
                    section to estimate baseline pollutant concentrations of treated streams for
                    this analysis.

              5.     Incorporated limits on wastewater discharged from sites not regulated by
                    40 CFR 413 or 433  (Baseline for the Local Limits to  433 Upgrade
                    Analysis). For the final rule, in response to comments, EPA also
                    incorporated changes to take into account the compliance of indirect
                    dischargers in the General Metals Subcategory, not currently regulated by
                    Parts 413  or 433, with local limits. Although EPA could not obtain  actual
                    local limits for all facilities, EPA gathered local limits data from 213
                    POTWs in seven EPA Regions to develop national median local limit
                    values, (see DCN 17844 of the rulemaking record for a list of the data and
                    the median value for each parameter). EPA assumed  the treated streams
                    achieved one-half of the national median local limit values3 for all
                    parameters regulated by Part 433. For parameters not regulated by Part
                    433, EPA assumed the treated streams achieved the national median local
                    limit values. EPA conducted a unique analysis to determine the costs and
                    loads associated with the upgrade of facilities not regulated under Parts
                    413 or 433 to meet the Part 433 limits. EPA used the methodology
                    described  in this section to estimate baseline pollutant concentrations of
                    treated streams for this analysis.

12.2.1.3       Estimation of Commingled Effluent Pollutant Concentrations from Sites

              EPA combined the wastewater from treated and untreated streams. EPA
calculated the commingled baseline effluent pollutant concentration of each POC in the
combined MP&M wastewater based on pollutant concentrations and flow rates of each stream
(treated and untreated).

              EPA received comments that, although the concentration of chemical oxygen
demand (COD) in discharged wastewater is not regulated by Parts 413 or 433 (unlike oil and
3EPA used !/2 the median value to take into account that facilities do not operate treatment systems to achieve the
limit, but some value below the limit to account for variability.

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grease and total suspended solids), it is typically regulated by local limits.  EPA reviewed data
from the Permit Compliance System (PCS) and found that, while COD is not generally regulated
by local limitations, a small number of facilities do have COD restrictions.  EPA found similar
results for total kjeldahl nitrogen (TKN) and ammonia as nitrogen (NH)4.  Since EPA could not
identify which sites in PCS may have been subject to MP&M, EPA conducted its analysis using
information from process wastewater dischargers from facilities in the 3000 series SIC codes.
Using information from those sites with COD, TKN, and NH limitations, EPA calculated a
single local limit value for each parameter. These values are 175, 35.67, and 19.3 mg/L for
COD, TKN, and NH, respectively.  EPA compared the baseline pollutant concentrations it
predicted for these pollutants at each site.  If these concentrations were in excess of the local
limit value, then EPA set the concentration for the commingled MP&M wastewater discharged
from each model site in metal-bearing wastewater subcategories equal to the local limit value.
Details are provided in the memorandum "Loadings Methodology for Cost Model Run 4" (DCN
17846 in Section 24.7 of the rulemaking record).

12.2.2        Estimation of Baseline Pollutant Concentrations from Sites in the Oil-
              Bearing Subcategories

              For the proposal and the NOD A, EPA's methodology to estimate baseline
pollutant concentrations  for facilities in oil-bearing wastewater subcategories was similar to the
one used at that time for metal-bearing wastewater subcategories.  EPA received comment on the
proposal and NODA that this methodology overestimated baseline pollutant concentrations for
Shipbuilding Dry Dock,  Railroad Line Maintenance, and Oily Waste sites.  In response to these
comments, EPA significantly revised its methodology for estimating baseline pollutant
concentrations in the oil-bearing wastewater subcategories.  Because EPA has different types of
information in its database for each oil-bearing wastewater subcategory, it used different methods
to represent baseline pollutant concentrations for each oil-bearing wastewater subcategory. The
final methodologies used for each oil-bearing wastewater subcategory are described individually
below.

12.2.2.1       Estimation of Baseline Pollutant Concentrations from Sites in the
              Shipbuilding Dry Dock Subcategory

              For the final rule, EPA used its sampling  data and  industry supplied long-term
monitoring data to estimate baseline pollutant concentrations for this subcategory. This data
includes pollutant concentrations measured at two EPA sampling episodes and those reported in
three years of Detailed Monitoring Reports (DMR) covering numerous dry dock discharges from
a single shipbuilding dry dock facility. In estimating baseline pollutant concentrations in this
manner, EPA looked at the individual data points as well as averages for its conclusions.  See
DCNs 17859 and 17860 in Sections 24.6.1 and 24.5.1 of the final rulemaking record for
additional information.  Note that for the final rule, EPA only estimated baseline concentrations
for total suspended solids (TSS) and oil and grease because EPA  had previously determined that
4EPA reviewed these parameters because they were important in estimating benefits (see the Economic.
Environmental, and Benefits Analysis for the Final MP&M Rule (EEBA)).

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                                                           12.0 - Pollutant Loading and Reduction Estimates

discharges from these facilities contain minimal concentrations of toxic organic and metal
pollutants.

12.2.2.2       Estimation of Baseline Pollutant Concentrations from Sites in the Railroad
              Line Maintenance Subcategory

              In response to proposal and NODA comments, EPA revisited its database of
direct discharging Railroad Line Maintenance facilities. EPA found that many of the facilities in
its database would not be subject to this rule because they discharged only noncontaminated
stormwater or wastewater resulting from refueling operations (neither of which is subject to the
final rule). As a result of this review, EPA concluded its database was insufficient to make any
regulatory decisions on direct discharging Railroad Line Maintenance facilities.

              However, as part of its comments on the proposed rule and as discussed more
fully in the NODA (67 FR 38755), the American Association of Railroads (AAR) provided a
census listing of each Railroad Line Maintenance direct discharging facility known to them.  For
each facility, AAR provided a description of treatment technologies, a summary of effluent data,
including flow rates, permit limits, and a process flow diagram or description of the operations.
For the final rule, EPA used this information to create a new database representing direct
discharging Railroad Line Maintenance facilities.

              EPA's final database consists of nine direct discharging Railroad Line
Maintenance facilities.  Six of the nine facilities use technologies consistent with the Option 6
technology basis, two use technologies consistent with the Option 10 technology basis, and one
uses biological treatment.

              For the final rule, EPA did not need to model effluent pollutant concentrations for
each of the final database facilities. Rather, EPA used the summary effluent data provided for
each facility to represent baseline oil and grease and TSS concentrations in the Railroad Line
Maintenance Subcategory. For additional information, see DCN 17861 in Section 24.6.1 of the
rulemaking record. Note that EPA considered only TSS and oil and grease because it had
previously determined that discharges in this Subcategory contain few pounds of toxic pollutants.

12.2.2.3       Estimation of Baseline Pollutant Concentrations from Sites in the Oily
              Wastes Subcategory

              For the final rule, EPA estimated baseline pollutant concentrations using a
different methodology for treated and untreated streams in the oily waste Subcategory.

Treated Streams:     Where EPA had survey information (DMR data) for a particular site with
                    treatment, EPA used that information as the baseline pollutant
                    concentration. For half of the oily waste Subcategory facilities with
                    treatment, however, EPA had to estimate baseline pollutant
                    concentrations.  In all of these cases, EPA determined the treatment
                    currently in place would achieve equivalent or greater removals to the

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                    treatment technology considered as the technology basis for limitations in
                    this sub category (Option 6).  Therefore, where EPA did not have DMR
                    data for a facility with treatment in place, EPA estimated its baseline
                    pollutant concentrations as the median effluent concentrations of the DMR
                    data from facilities with the option 6 technology.

Untreated Streams:   EPA had DMR data for one site that indicated no treatment.  Therefore,
                    EPA used this data as the baseline pollutant concentrations for this facility.
                    For the remaining sites without treatment, EPA had to estimate baseline
                    pollutant concentrations. For these sites, EPA estimated unit operation
                    wastewater pollutant concentrations using the methodology described in
                    Section 12.1. EPA notes that it  significantly revised the unit operations
                    data between the proposal and the NOD A, and between the NODA and
                    final rule based on comments on the NODA (see DCN 16764, in Section
                    16.7 of the rulemaking record).  EPA combined the wastewater from all
                    unit operation discharges that are not sent through treatment. EPA
                    calculated the commingled concentration of each POC in the combined
                    MP&M wastewater based on pollutant concentrations and flow rates of
                    each stream.

12.2.3        Estimation of Model Site Baseline Loadings

              EPA estimated the pollutant loadings (Ibs/yr) in effluent wastewater (treated or
untreated) discharged from each MP&M model site. EPA estimated pollutant-specific baseline
loadings by multiplying the effluent pollutant concentration of the pollutant by the corresponding
effluent wastewater flow rate. To determine site-specific pollutant baseline loadings for sites that
have both treated and untreated streams, EPA summed the estimated pollutant-specific baseline
loading from the untreated effluent and the treated effluent.  EPA estimated site-specific baseline
loadings by summing site-specific pollutant baseline loadings for all pollutants considered.

              For direct dischargers in the General Metals Subcategory, EPA additionally
compared the baseline pollutant loadings from EPA's Costs & Loadings Model to available
DMR data. EPA obtained DMR data for 18 of the model sites. The MP&M model did not
overestimate baseline loadings for 12 of these  18 model direct discharging facilities (or
approximately two-thirds of these facilities). The relative percent difference (in pound-
equivalents) of the model baseline loadings and those estimated using DMR data is 14 percent.
Based on this analysis, EPA concluded that the MP&M model estimates of baseline pollutant
loadings are reasonable and appropriate.

12.2.4        Estimation of Industry-Wide Baseline Pollutant Loadings

              EPA multiplied the site-specific baseline wastewater loadings by the
corresponding statistically derived weighting factors (see Section 3.0) for each model site. EPA
summed the weighted loadings across all sites in each  subcategory to estimate
subcategory-specific baseline wastewater pollutant loadings. EPA also summed the weighted

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loadings across all sites to estimate industry-wide baseline wastewater pollutant loadings.  Table
12-2 presents the estimated baseline pollutant loadings by subcategory for direct and indirect
dischargers.

12.3          Estimation of Industry Option Pollutant Loadings

              Industry option pollutant loadings (i.e., post-compliance pollutant loadings for the
technology option) represent the total loadings of pollutants in all MP&M wastewater that would
be discharged to surface waters or POTWs after complying with the regulatory option. The
estimation of industry option pollutant loadings for each subcategory is described in the
following subsections.

12.3.1        Estimation of Industry Option Pollutant Loadings for Sites in the Metal-
              Bearing Subcategories

              Direct Dischargers (General Metals Subcategory).  EPA estimated option effluent
concentrations assuming that all direct discharging MP&M facilities in the General Metals
Subcategory would achieve long-term average effluent pollutant concentrations associated with
the MP&M sampled  sites performing BAT (Option 2, including chemical precipitation with
clarification). EPA estimated effluent concentrations for all pollutants of concern (listed in
Section 7.0).  Note that if the long-term average effluent concentration for a pollutant was more
than its corresponding treatment influent concentration (based on unit operation wastewater
concentrations), EPA retained the treatment influent concentration to estimate the option effluent
concentration for that pollutant.

              Indirect Dischargers - 413 to 433 Upgrade Analysis for sites regulated by 40
CFR 413 only (General Metals, Printed Wiring Board, and Metal Finishing Job Shop
Subcategories).  EPA estimated option effluent concentrations assuming all  indirect discharging
MP&M facilities in metal-bearing Subcategories, currently regulated by 40 CFR 413  only, would
achieve long-term average effluent pollutant concentrations associated with the BAT sites
sampled under development of 40 CFR 433 (at the option). EPA estimated effluent
concentrations only for pollutants regulated under 40 CFR 433.

              Indirect Dischargers - Local Limits to 433 Upgrade Analysis for sites regulated
by local limits (GeneralMetals Subcategory). EPA estimated option effluent concentrations
assuming all indirect discharging facilities in the General Metals Subcategory, not currently
regulated by 40 CFR 413 or 433, would achieve long-term average effluent pollutant
concentrations associated with the BAT sites sampled under development of 40 CFR 433 (at the
option). For pollutants regulated under local limits, but not regulated under Part 433, EPA
assumed the facilities would achieve the national median local limit values.  EPA estimated
effluent concentrations only for pollutants regulated under local limits.

              EPA then estimated post-compliance pollutant loadings for each model facility by
multiplying the treated effluent concentration by its wastewater  flow rate to obtain a mass
loading (in pounds) for each pollutant.  Finally, EPA estimated site-specific option loadings.

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EPA summed the mass loadings for all pollutants in the final effluent discharged from the model
site.

12.3.2        Estimation of Industry Option Pollutant Loadings for Sites in the
             Shipbuilding Dry Dock Subcategory

             Because EPA concluded that national regulation of discharges from the
Shipbuilding Dry Dock Subcategory is unwarranted5, EPA did not assess option pollutant
loadings for this Subcategory.

12.3.3        Estimation of Industry Option Pollutant Loadings for Sites in the Railroad
             Line Maintenance Subcategory

             For this Subcategory, EPA used information in its database on current permit
limitations for facilities operating the Option 6 technology to estimate post-compliance pollutant
loadings.  All of the facilities that operate the Option 6 technology have a daily maximum oil and
grease limit of 15 mg/L.  For TSS, half of the facilities have a daily maximum limit of 45 mg/L
while the other half have no limit.  Based on this information, the oil and grease and TSS daily
maximum limits representing the average of the best performing Option 6 facilities would be 15
mg/L and  45 mg/L, respectively. To estimate pollutant loadings for each model facility, EPA
multiplied these maximum limits by the wastewater flow (provided in the survey) to obtain a
mass loading (in pounds) for TSS.

12.3.4        Estimation of Industry Option Pollutant Loadings for Sites in the Oily
             Wastes Subcategory

             EPA calculated the loadings assuming that all Oily Wastes sites would achieve
long-term  average effluent pollutant concentrations associated with the MP&M sampled sites
performing BAT (Option 6, including chemical emulsion breaking with gravity oil/water
separation).

             First, EPA estimated the pollutant concentrations in the effluent from treatment at
each model site, using the LTAs calculated from MP&M BAT sampled sites. The calculated
LTAs for oil and grease and TSS are 18.89 mg/L and 44 mg/L, respectively. Note that if the
long-term  average effluent concentration for a pollutant was more than its corresponding
treatment influent concentration (based on unit operation wastewater concentrations), EPA
retained the treatment influent concentration to estimate the option concentration for that
pollutant.

             Second, EPA estimated site-specific pollutant loadings. EPA multiplied the
pollutant concentrations in the final effluent (discharged from the model site) by the wastewater
5See Section VI.H of the final preamble for additional discussion.

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                                                          12.0 - Pollutant Loading and Reduction Estimates

flow rate (calculated in the EPA Costs & Loadings Model, or provided in the DMR) to obtain a
mass loading (in pounds) for each pollutant.

              Finally, EPA estimated site-specific option loadings. EPA summed the mass
loadings for all pollutants in the final effluent discharged from the model site.

12.4          Estimation of Pollutant Reductions

              Option pollutant reductions represent the incremental amount of pollutants
removed by each technology option with respect to EPA's estimated baseline pollutant loadings.
EPA estimated baseline pollutant loadings as explained in Section 12.2.  EPA estimated option
pollutant loadings as explained in Section 12.3.  EPA estimated pollutant reductions as follows:

              1.     Estimated site-specific, pollutant-specific option removals.  EPA
                    calculated the difference between the model  site's baseline pollutant
                    loadings and option pollutant loadings.  For direct dischargers, EPA
                    considered all pollutants of concern, with the exception of boron, sodium,
                    calcium, and total dissolved solids. For indirect dischargers, EPA
                    considered only pollutants regulated under 40 CFR 433. EPA further
                    reduced the model site's option-specific pollutant removals for indirect
                    dischargers by their corresponding POTW percent removal (listed in Table
                    12-1) to account for treatment that will occur at the POTW. A detailed
                    discussion of how EPA developed pollutant-specific POTW percent
                    removals is provided in Section 7.3.1 of the Technical Development
                    Document for the Proposed Effluent Limitations Guidelines and Standards
                    for the Metal Products and Machinery Point  Source Category.

              2.     Modified site-specific, pollutant-specific option removals.  First, if the
                    option-specific concentration for certain pollutant(s) was greater than the
                    estimated baseline concentration for a model site,  EPA set option-specific
                    loadings for the pollutant(s) equal to the baseline loadings at those sites
                    (EPA set the option-specific pollutant removal for that model site equal  to
                    zero).  This was the case if the pollutant long-term average concentration
                    for the treatment currently in place at the site was  lower than that for
                    EPA's treatment technology option (i.e., a model facility uses membrane
                    technology, but EPA's option  technology is chemical precipitation).
                    Second, EPA set all removals  of boron equal to zero. EPA determined
                    that boron is not rem