United States
Envi-onmcn'.ai Piotecvgn
Agency
industrial Technology
WH552
Washington, DC 20460
EPAM0.1-B&070
October 1965
Water
Final
Development
Document for
Effluent Limitations
Guidelines and
Standards for the
Metal Molding and Casting
(Foundries)
Point Source Category
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DEVELOPMENT DOCUMENT
FOR
EFFLUENT LIMITATIONS GUIDELINES
NEW SOURCE PERFORMANCE STANDARDS
AND
PRETREATMENT STANDARDS
FOR THE
METAL MOLDING AND CASTING
(FOUNDRIES)
POINT SOURCE CATEGORY
Lee M. Thomas
Administrator
James M, Conlon
Acting Director
Office of Water Regulations and Standards
Jeffery D, Denitr Director
Industrial Technology Division
Robert W. Dellinger
Chief, Consumer Commodities Branch
Donald F. Anderson
Senior Project Officer
October 1985
Industrial Technology Division
Office of Water Regulations and Standards
U.S. Environmental Protection Agency
Washington, D.C, 20460
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TABLE OF CONTENTS
SECTION SUBJECT
I. SUMMARY AND CONCLUSIONS
II. RECOMMENDATIONS
III. INTRODUCTION
Legal Authority 41
Summary of Methodology 43
Data Gathering Efforts 45
Description of the Metal Molding and
Casting (Foundry) Industry 56
Description of Metal Molding and
Casting Industry Processes 62
Profile of Plants in the Metal Molding
and Casting Point Source Category 75
IV. INDUSTRY SUBCATEGORIZATION
Introduction 93
Selected Subcategories 93
Subcategory and Process Segment
Definitions 96
Subcategorization Basis 101
Production Normalizing Parameters 108
V. WATER USE AND WASTE CHARACTERIZATION 113
Data Sources
Metal Molding and Casting
Industry Data Base 113
Sampling and Analysis Program 113
Site Selection Rationale and
Sampling History 115
Water Use and Waste Characteristics 120
Aluminum Subcategory 121
Copper Subcategory 129
Ferrous Subcategory 135
Magnesium Subcategory 147
Zinc Subcategory 150
VI. SELECTION OF POLLUTANTS TO BE CONSIDERED
FOR REGULATION 273
Rationale for Pollutant Selection 273
Pollutant Selection by Subcategory 274
Organic Priority Pollutant
Selection by Process Segment 275
Pollutant Selection for the
Aluminum Subcategory 276
Pollutant Selection for the
Copper Subcategory 281
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TABLE OF CONTENTS (Continued)
SECTION SUBJECT PAGE
VI. Pollutant Selection for the
Ferrous Subcategory 284
Pollutant Selection for the
Magnesium Subcategory 287
Pollutant Selection for the
Zinc Subcategory 290
VII. CONTROL AND TREATMENT TECHNOLOGY 311
Introduction 311
End-of-Pipe Treatment Technologies 311
Major Technologies 312
Carbon Adsorption 312
Chemical Precipitation 314
Emulsion Breaking 318
Granular Bed Filtration 321
Oxidation by Potassium
Permanganate 324
Pressure Filtration 326
Settling 327
Skimming 330
Vacuum Filtration 332
Minor Technologies 333
Centrifugation 333
Coalescing 335
Flotation 336
Gravity Sludge Thickening 339
Sludge Bed Drying 340
Ultrafiltration 341
In-Process Pollution Control
Techniques 343
Generally Applicable In-Process
Control Techniques 343
Wastewater Segregation 344
Wastewater Recycle and Reuse 344
Water Use Reduction 346
Contract Hauling 347
Lubricating Oil Recovery 347
Dry Air Pollution Control
Devices 347
Good Housekeeping 348
Development of Control and Treatment
Options 349
Development of Treatment Effectiveness
Values 352
11
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TABLE OP CONTENTS (Continued)
SECTION SUBJECT PAGE
VIII. COST, ENERGY, AND NON-WATER QUALITY IMPACTS
Cost Estimation 409
Model Plant Costs 410
Utilization Factors 414
Projected Number of Dischargers 415
Calculation of Industry Costs 415
Segregation Costs 417
Central Treatment Costs 419
Pollutant Removal Estimates 420
Energy and Non-Water Quality Impacts 421
Energy Requirements 421
Air Pollution 421
Solid Waste 421
Consumptive Water Loss 423
IX. BEST PRACTICABLE CONTROL TECHNOLOGY J
CURRENTLY AVAILABLE 457
Introduction 457
Technical Approach to BPT 457
BPT Option Selection 458
Regulated Pollutant Parameters 459
BPT Flows 461
BPT Effluent Limitations 462
BPT Development by Subcategory and
Process Segment 463
Non-Water Quality Aspects of BPT 480
X. BEST AVAILABLE TECHNOLOGY ECONOMICALLY
ACHIEVABLE 491
Introduction 491
Technical Approach to BAT 491
BAT Option Selection 492
Regulated Pollutant Parameters 494
BAT Flows 495
BAT Effluent Limitations 496
Cost of Application and Effluent
Reduction Benefits 496
Non-Water Quality Aspects of BAT 496
XI. BEST CONVENTIONAL POLLUTANT CONTROL
TECHNOLOGY 507
ill
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TABLE OF CONTENTS (Continued)
SECTION SUBJECT PAGE
XII. NEW SOURCE PERFORMANCE STANDARDS 509
Introduction 509
Technical Approach to Establishing
NSPS 509
NSPS Technology Option Selection 510
Regulated Pollutant Parameters 510
NSPS Flow 510
NSPS Effluent Standards 510
Cost of Application and Effluent
Reductions Benefits 511
Non-Water Quality Aspects of NSPS 511
XIII. PRETREATMENT STANDARDS 523
Introduction 523
Technical Approach to Establishing
Pretreatment Standards 523
Pass Through Analysis 524
PSES and PSNS Option Selection 527
Regulated Pollutant Parameters 527
PSES/PSNS Flow 528
PSES/PSNS Effluent Standards 528
Cost of Application and Effluent
Reduction Benefits 529
Non-Water Quality Aspects of
PSES/PSNS 529
XIV. ACKNOWLEDGMENTS 537
XV. REFERENCES 539
XVI. GLOSSARY 543
Appendix A - Toxic Organic Pollutants
Included in TTO for Each Process
Segment 565
Appendix B - Water Chemistry Recycle
Model Sensitivity Analyses 575
Appendix C - Guidance for Implementing
the Metal Molding and Casting Category
Regulations 591
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LIST OF TABLES
Number Page
1-1 POLLUTANT PARAMETERS REGULATED 6
1-2 APPLIED FLOW RATES, RECYCLE RATES, AND
DISCHARGE RATES THAT FORM THE BASIS OF BPT 8
II-l BPT LIMITATIONS COVERING CONTINUOUS DIRECT
DISCHARGES 12
II-2 BPT LIMITATIONS COVERING NON-CONTINUOUS
DIRECT WASTEWATER DISCHARGES 14
II-3 BAT LIMITATIONS COVERING CONTINUOUS DIRECT
DISCHARGES 18
II-4 BAT LIMITATIONS COVERING NON-CONTINUOUS
DIRECT WASTEWATER DISCHARGES 22
II-5 NSPS LIMITATIONS COVERING CONTINUOUS DIRECT
DISCHARGES 25
II-6 NSPS LIMITATIONS COVERING NON-CONTINUOUS
DIRECT WASTEWATER DISCHARGES 28
II-7 PSES LIMITATIONS COVERING CONTINUOUS
INDIRECT DISCHARGES 34
II-8 PSNS LIMITATIONS COVERING CONTINUOUS
INDIRECT DISCHARGES 37
III-l PENTON FOUNDRY CENSUS INFORMATION 80
III-2 FOUNDRY SHIPMENTS IN THE UNITED STATES 81
III-3 DISTRIBUTION OF WET AND DRY PLANTS IN
THE METAL MOLDING AND CASTING INDUSTRY 82
III-4 PERCENTAGE OF ACTIVE "MET" OPERATIONS
WITHIN EACH EMPLOYEE GROUP 83
V-l APPLIED FLOW RATES FOR ALUMINUM CASTING
CLEANING 154
V-2 APPLIED FLOW RATES FOR ALUMINUM CASTING
QUENCH 155
V-3 APPLIED FLOW RATES FOR ALUMINUM DIE
CASTING 156
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LIST OF TABLES (Continued)
Number Page
V-4 APPLIED FLOW RATES FOR ALUMINUM DOST
COLLECTION SCRUBBER 157
V-5 APPLIED FLOW RATES FOR ALUMINUM GRINDING
SCRUBBER 158
V-6 APPLIED FLOW RATES FOR ALUMINUM, COPPER,
AND FERROUS INVESTMENT CASTING 158
V-7 APPLIED FLOW RATES FOR ALUMINUM MELTING
FURNACE SCRUBBER 159
V-8 APPLIED FLOW RATES FOR ALUMINUM MOLD
COOLING 160
V-9 APPLIED FLOW RATES FOR COPPER CASTING
QUENCH 161
V-10 APPLIED FLOW RATES FOR COPPER DIRECT
CHILL CASTING 162
V-ll APPLIED FLOW RATES FOR COPPER DUST
COLLECTION SCRUBBER 162
V-12 APPLIED FLOW RATES FOR COPPER GRINDING
SCRUBBER 163
V-13 APPLIED FLOW RATES FOR COPPER MELTING
FURNACE SCRUBBER 163
V-14 APPLIED FLOW RATES FOR COPPER MOLD
COOLING 164
V-15 APPLIED FLOW RATES FOR FERROUS CASTING
CLEANING 165
V-16 APPLIED FLOW RATES FOR FERROUS CASTING
QUENCH 166
V-17 APPLIED FLOW RATES FOR FERROUS DUST
COLLECTION SCRUBBER 168
V-18 APPLIED FLOW RATES FOR FERROUS GRINDING
SCRUBBER 176
V-19 APPLIED FLOW RATES FOR FERROUS MELTING
FURNACE SCRUBBER 178
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LIST OF TABLES (Continued)
Number Page
V-20 APPLIED FLOW RATES FOR FERROUS MOLD
COOLING 182
V-21 APPLIED FLOW RATES FOR FERROUS SLAG
QUENCH 183
V-22 APPLIED FLOW RATES FOR FERROUS WET SAND
RECLAMATION 186
V-23 APPLIED FLOW RATES FOR MAGNESIUM CASTING
QUENCH 187
V-24 APPLIED FLOW RATES FOR MAGNESIUM DUST
COLLECTION SCRUBBER 187
V-25 APPLIED FLOW RATES FOR MAGNESIUM GRINDING
SCRUBBER 187
V-26 APPLIED FLOW RATES FOR ZINC CASTING
QUENCH 188
V-27 APPLIED FLOW RATES FOR ZINC DIE CASTING 189
V-28 APPLIED FLOW RATES FOR ZINC MELTING
FURNACE SCRUBBER 190
V-29 APPLIED FLOW RATES FOR ZINC MOLD COOLING 190
V-3Q METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-ALUMINUM CASTING QUENCH-RAW
WASTEWATER 191
V-31 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-ALUMINUM DIE CASTING-RAW
WASTEWATER 193
V-32 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-ALUMINUM INVESTMENT CASTING-RAW
WASTEWATER 195
V-33 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-ALUMINUM MELTING FURNACE
SCRUBBER-RAW WASTEWATER 197
V-34 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-COPPER DIRECT CHILL CASTING-RAW
WASTEWATER 198
vii
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LIST OF TABLES (Continued)
Table Pa<
V-35 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-COPPER DUST COLLECTION SCRUBBER-RAW
WASTEWATSR 199
V-36 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-COPPER MOLDING COOLING-RAW
WASTEWATER 201
V-37 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-FERROUS CASTING CLEANING-RAW
WASTEWATER 202
V-38 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-FERROUS CASTING QUENCH-RAW
WASTEWATER 203
V-39 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-FERROUS DUST COLLECTION
SCRUBBER-RAW WASTEWATER 204
V-40 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-FERROUS MELTING FURNACE SCRUBBER-
RAW WASTEWATER 207
V-41 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-FERROUS MOLD COOLING-RAW
WASTEWATER 209
V-42 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-FERROUS SLAG QUENCH-RAW
WASTEWATER 210
V-43 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-FERROUS WET SAND RECLAMATION-RAW
WASTEWATER 211
V-44 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-MAGNESIUM GRINDING SCRUBBER-RAW
WASTEWATER 213
V-45 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-ZINC CASTING QUENCH-RAW WASTEWATER 214
V-46 METAL MOLDING AND CASTING ANALYTICAL DATA
SUMMARY-ZINC DIE CASTING-RAW WASTEWATER 216
V-47 LIST OF 129 PRIORITY POLLUTANTS 218
Vlll
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LIST OP TABLES (Continued)
Page
NON-PRIORITY POLLUTANTS ANALYZED FOR
DURING MM&C SAMPLING EFFORTS 223
V-49 SUMMARY OP SAMPLING ACTIVITIES 224
VI-1 FREQUENCY OF OCCURRENCE OF CONVENTIONAL
AND NONCONVENTIONAL POLLUTANT PARAMETERS
IN THE ALUMINUM SUBCATEGORY 294
VI-2 FREQUENCY OF OCCURRENCE OF THE PRIORITY
POLLUTANTS - ALUMINUM SUBCATEGORY 295
VI-3 FREQUENCY OF OCCURRENCE OF CONVENTIONAL
AND NONCONVENTIONAL POLLUTANT PARAMETERS
IN THE COPPER SUBCATEGORY 297
VI-4 FREQUENCY OF OCCURRENCE OF THE PRIORITY
POLLUTANTS - COPPER SUBCATEGORY 298
VI-5 FREQUENCY OF OCCURRENCE OF CONVENTIONAL
AND NONCONVENTIONAL POLLUTANT PARAMETERS
IN THE FERROUS SUBCATEGORY 299
VI-6 FREQUENCY OF OCCURRENCE OF THE PRIORITY
POLLUTANTS - FERROUS SUBCATEGORY 300
VI-7 FREQUENCY OF OCCURRENCE OF CONVENTIONAL
AND NONCONVENTIONAL POLLUTANT PARAMETERS
IN THE MAGNESIUM SUBCATEGORY 302
VI-8 FREQUENCY OF OCCURRENCE OF THE PRIORITY
POLLUTANTS - MAGNESIUM SUBCATEGORY 303
VI-9 FREQUENCY OF OCCURRENCE OF CONVENTIONAL
AND NONCONVENTIONAL POLLUTANT PARAMETERS
IN THE ZINC SUBCATEGORY 304
VI-1Q FREQUENCY OF OCCURRENCE OF THE PRIORITY
POLLUTANTS - ZINC SUBCATEGORY 305
VI-11 ORGANIC PRIORITY POLLUTANTS CONSIDERED FOR
REGULATION IN EACH PROCESS SEGMENT -
ALUMINUM SUBCATEGORY 306
VI-12 ORGANIC PRIORITY POLLUTANTS CONSIDERED FOR
REGULATION IN EACH PROCESS SEGMENT - COPPER
SUBCATEGORY 307
lx
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LIST OF TABLES (Continued)
Table Page
VI-13 ORGANIC PRIORITY POLLUTANTS CONSIDERED FOR
REGULATION IN EACH PROCESS SEGMENT -
FERROUS SDBCATEGORY 308
VI-14 ORGANIC PRIORITY POLLUTANTS CONSIDERED FOR
REGULATION IN EACH PROCESS SEGMENT -
MAGNESIUM SUBCATEGORY 309
Vl-15 ORGANIC PRIORITY POLLUTANTS CONSIDERED FOR
REGULATION IN EACH PROCESS SEGMENT - ZINC
SUBCATEGORY 310
VII-1 TREATMENT TECHNOLOGY DEMONSTRATION STATUS 370
VII-2 CLASSES OF ORGANIC COMPOUNDS ADSORBED ON
CARBON 371
VII-3 THEORETICAL SOLUBILITIES OF HYDROXIDES,
CARBONATES, AND SULFIDES OF SELECTED
METALS IN PURE WATER 372
VII-4 RECYCLE DEMONSTRATION STATUS 373
VI1-5 METAL MOLDING AND CASTING LIME AND SETTLE
TREATMENT EFFECTIVENESS CONCENTRATIONS
EPA AND CONFIRMED DMR DATA 375
VII-6 METAL MOLDING AND CASTING LIME AND SETTLE
TREATED EFFLUENT CONCENTRATIONS INDIVIDUAL
PLANT DATA FOR COPPER 376
VII-7 METAL MOLDING AND CASTING LIME AND SETTLE
TREATED EFFLUENT CONCENTRATIONS INDIVIDUAL
PLANT DATA FOR LEAD 377
VII-8 METAL MOLDING AND CASTING LIME AND SETTLE
TREATED EFFLUENT CONCENTRATIONS INDIVIDUAL
PLANT DATA FOR ZINC 378
VII-9 METAL MOLDING AND CASTING LIME AND SETTLE
TREATED EFFLUENT CONCENTRATIONS INDIVIDUAL
PLANT DATA FOR OIL AND GREASE 379
VII-10 METAL MOLDING AND CASTING LIME AND SETTLE
TREATED EFFLUENT CONCENTRATIONS INDIVIDUAL
PLANT DATA FOR PHENOL 380
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LIST OF TABLES (Continued)
Table Page
VII-11 METAL MOLDING AND CASTING LIME AND SETTLE
TREATED EFFLUENT CONCENTRATIONS INDIVIDUAL
PLANT DATA FOR TOTAL SUSPENDED SOLIDS 381
VII-12 TREATMENT EFFECTIVENESS CONCENTRATIONS FOR
THE METAL MOLDING AND CASTING CATEGORY -
OPTION 2 382
VII-13 TREATMENT EFFECTIVENESS CONCENTRATIONS FOR
PRIORITY TOXIC ORGANIC POLLUTANTS 383
VII-14 TREATMENT EFFECTIVENESS CONCENTRATIONS FOR
THE METAL MOLDING AND CASTING CATEGORY -
OPTION 3 385
VII-15 LIME AND SETTLE EFFLUENT DATA COMPARISON
BETWEEN THE COMBINED METALS DATA BASE AND
METAL MOLDING CASTING DATA 386
VII-16 MULTIMEDIA FILTER PERFORMANCE 387
VIII-1 METAL MOLDING AND CASTING INDUSTRY
GUIDELINES MODEL COSTS 424
VIII-2 MODEL PLANT COSTS - OPTION 1 425
VIII-3 MODEL PLANT COSTS - OPTION 2 430
VIII-4 MODEL PLANT COSTS - OPTION 3 435
VIII-5 MODEL PLANT COSTS - OPTION 4 440
VIII-6 MODEL PLANT COSTS - OPTION 5 445
VIII-7 PROJECTED NUMBER OF ACTIVE WET PROCESSES
IN THE METAL MOLDING AND CASTING INDUSTRY 446
VIII-8 ESTIMATED INSTALLED CAPITAL COSTS FOR
SEGREGATION OF NONCONTACT COOLING WATER 451
VIII-9 SELECTED PROCESS SEGMENT COMBINATIONS
FOR CENTRAL TREATMENT COST STUDY 452
VIII-10 INCREMENTAL POLLUTANT REMOVAL ESTIMATES
DUE TO APPLICATION OF MODEL TREATMENT
TECHNOLOGY 453
XI
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LIST OP TABLES (Continued)
Table Page
VIII-11 NET INCREASE IN ELECTRICAL ENERGY
CONSUMPTION DOE TO APPLICATION OF MODEL
TREATMENT TECHNOLOGY 454
VIII-12 INCREMENTAL INCREASE IN SOLID WASTE
GENERATION DOE TO APPLICATION OF MODEL
TREATMENT TECHNOLOGY 455
VIII-13 CONSUMPTIVE WATER LOSS DUE TO APPLICATION
OF HIGH RATE RECYCLE 456
IX-1 APPLIED FLOW RATES, RECYCLE RATES, AND
DISCHARGE RATES THAT FORM THE BASIS OP BPT 482
IX-2 BPT LIMITATIONS COVERING CONTINUOUS DIRECT
DISCHARGE 484
IX-3 BPT LIMITATIONS COVERING NON-CONTINUOUS
DIRECT WASTEWATER DISCHARGES 486
X-l APPLIED FLOW RATES, RECYCLE RATES, AND
DISCHARGE RATES THAT FORM THE BASIS OF BAT 498
X-2 BAT LIMITATIONS COVERING CONTINUOUS DIRECT
DISCHARGES 500
X-3 BAT LIMITATIONS COVERING NON-CONTINUOUS
DIRECT WASTEWATER DISCHARGES 503
XII-1 APPLIED FLOW RATES, RECYCLE RATES, AND
DISCHARGE RATES THAT FORM THE BASIS OP
NSPS 512
XII-2 NSPS LIMITATIONS COVERING CONTINUOUS
DIRECT DISCHARGES 514
XII-3 NSPS LIMITATIONS COVERING NON-CONTINUOUS
DIRECT WASTEWATER DISCHARGES 517
XZII-1 PASS-THROUGH ANALYSIS 531
XIII-2 APPLIED FLOW RATES, RECYCLE RATES, AND
DISCHARGE RATES THAT FORM THE BASIS OF
PSES AND PSNS 532
XIII-3 PSES AND PSNS LIMITATIONS COVERING
CONTINUOUS INDIRECT DISCHARGES 534
xii
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LIST OF TABLES (Continued)
Table Page
C-l PLANT A MAXIMUM FOR MONTHLY AVERAG1 BPT
EFFLUENT LIMITATIONS 602
C-2 PLANT A MAXIMUM FOR MONTHLY AVERAGE BAT
EFFLUENT LIMITATIONS 604
xiii
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LIST OP FIGURES
Figure Page
III-l FOUNDRY INDUSTRY STUDY PRODUCT FLOW
DIAGRAM 84
III-2 INVESTMENT FOUNDRY PROCESS FLOW DIAGRAM 85
III-3 ALUMINUM DIE CASTING PROCESS FLOW DIAGRAM 36
III-4 COPPER AND ALLOYS PROCESS FLOW DIAGRAM 37
III-5 FERROUS FOUNDRY PROCESS FLOW DIAGRAM 88
II1-6 MAGNESIUM FOUNDRY PROCESS FLOW DIAGRAM 89
111-7 ZINC DIE CASTING PROCESS FLOW DIAGRAM 90
II1-8 IRON FOUNDRY CUPOLA TYPE III PROCESS FLOW
DIAGRAM 91
II1-9 IRON FOUNDRY CUPOLA TYPE II PROCESS FLOW
DIAGRAM 92
V-l PLANT WATER FLOW DIAGRAM - PLANT 00001 226
V-2 PLANT WATER FLOW DIAGRAM - PLANT 00002 227
V-3 PLANT WATER FLOW DIAGRAM - PLANT 04622 228
V-4 PLANT WATER FLOW DIAGRAM - PLANT 04704 229
V-5 PLANT WATER FLOW DIAGRAM - PLANT 04736 230
V-6 PLANT WATER FLOW DIAGRAM - PLANT 06809 231
V-7 PLANT WATER FLOW DIAGRAM - PLANT 06956 232
V-8 PLANT WATER FLOW DIAGRAM - PLANT 07170 233
V-9 PLANT WATER FLOW DIAGRAM - PLANT 07929 234
V-10 PLANT WATER FLOW DIAGRAM - PLANT 08146 235
V-ll PLANT WATER FLOW DIAGRAM - PLANT 09094 236
V-12 PLANT WATER FLOW DIAGRAM - PLANT 09441 237
V-13 PLANT WATER FLOW DIAGRAM - PLANT 10308 238
xiv
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LIST OF FIGURES (continued)
.jigure Page
V-14 PLANT WATER FLOW DIAGRAM - PLANT 10837 239
V-15 PLANT WATER FLOW DIAGRAM - PLANT 12040 240
V-16 PLANT WATER FLOW DIAGRAM - PLANT 15265 241
V-17 PLANT WATER FLOW DIAGRAM - PLANT 15520 242
V-18 PLANT WATER FLOW DIAGRAM - PLANT 15654 243
V-19 PLANT WATER FLOW DIAGRAM - PLANT 17089 244
V-20 PLANT WATER FLOW DIAGRAM - PLANT 17230 245
V-21 PLANT WATER FLOW DIAGRAM - PLANT 18139 246
V-22 PLANT WATER FLOW DIAGRAM - PLANT 19872 247
V-23 PLANT WATER FLOW DIAGRAM - PLANT 20007 248
V-24 PLANT WATER FLOW DIAGRAM - PLANT 20009 249
V-25 PLANT WATER FLOW DIAGRAM - PLANT 20017 250
V-26 PLANT WATER FLOW DIAGRAM - PLANT 20147 251
V-27 PLANT WATER FLOW DIAGRAM - PLANT 50000 252
V-28 PLANT WATER FLOW DIAGRAM - PLANT 50315 253
V-29 PLANT WATER FLOW DIAGRAM - PLANT 51026 254
V-30 PLANT WATER FLOW DIAGRAM - PLANT 51115 255
V-31 PLANT WATER FLOW DIAGRAM - PLANT 51473 256
V-32 PLANT WATER FLOW DIAGRAM - PLANT 52491 257
V-33 PLANT WATER FLOW DIAGRAM - PLANT 52881 258
V-34 PLANT WATER FLOW DIAGRAM - PLANT 53219 259
V-35 PLANT WATER FLOW DIAGRAM - PLANT 53642 260
V-36 PLANT WATER FLOW DIAGRAM - PLANT 54321 261
V-37 PLANT WATER FLOW DIAGRAM - PLANT 55122 262
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LIST OP FIGURES (Continued)
Figure Page
V-38 PLANT WATER PLOW DIAGRAM - PLANT 55217 263
V-39 PLANT WATER FLOW DIAGRAM - PLANT 56123 264
V-40 PLANT WATER FLOW DIAGRAM - PLANT 56771 265
V-41 PLANT WATER FLOW DIAGRAM - PLANT 56789 266
V-42 PLANT WATER FLOW DIAGRAM - PLANT 57100 267
V-43 PLANT WATER FLOW DIAGRAM - PLANT 57775 268
V-44 PLANT WATER FLOW DIAGRAM - PLANT 58589 269
V-45 PLANT WATER FLOW DIAGRAM - PLANT 59101 270
V-46 PLANT WATER FLOW DIAGRAM - PLANT 59212 271
VII-1 ACTIVATED CARBON ADSORPTION COLUMN 388
VII-2 LEAD SOLUBILITY IN THREE ALKALIES 389
VII-3 GRANULAR BED FILTRATION 390
VII-4 PRESSURE FILTRATION 391
VI1-5 REPRESENTATIVE TYPES OP SEDIMENTATION 392
VII-6 GRAVITY OIL/WATER SEPARATOR 393
VII-7 VACUUM FILTRATION 394
VII-8 CENTRIFUGATION 395
VII-9 DISSOLVED AIR FLOTATION 396
VII-10 GRAVITY THICKENING 397
VII-11 SLUDGE DRYING BED 398
VII-12 SIMPLIFIED ULTRAFILTRATION FLOW SCHEMATIC 399
VII-13 WATER CHEMISTRY - GENERALIZED WASTEWATER
RECYCLE SYSTEM 400
VII-14 TREATMENT OPTION 1: RECYCLE AND SETTLE 401
xvi
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LIST OP FIGURES (Continued)
Figure Page
VII-15 TREATMENT OPTION 2j RECYCLE, LIME, AND
SETTLE 402
VII-16 TREATMENT OPTION 2 FOR ALUMINUM AND ZINC
DIE CASTING PROCESS SEGMENTS 403
VII-17 TREATMENT OPTION 3: RECYCLE, LIME, SETTLE,
AND FILTER 404
VII-18 TREATMENT OPTION 3 FOR ALUMINUM AND ZINC
DIE CASTING PROCESS SEGMENTS 405
VII-19 TREATMENT OPTION 4: RECYCLE, LIME, SETTLE,
FILTER, AND CARBON ADSORPTION 406
VII-20 TREATMENT OPTION 4 FOR ALUMINUM AND ZINC
DIE CASTING PROCESS SEGMENTS 407
VII-21 TREATMENT OPTION 5: SETTLE AND COMPLETE
RECYCLE 408
C-l BLOCK DIAGRAM OF EXAMPLE 1 - INTEGRATED
COPPER CASTING AND FORMING PLANT 600
C-2 BLOCK DIAGRAM OF EXAMPLE- 2 - ALUMINUM
AND ZINC DIE CASTING PLANT 606
C-3 COMBINED WASTESTREAMS FOR EXAMPLE 3 -
INTEGRATED GRAY IRON FOUNDRY AND HEAVY
EQUIPMENT MANUFACTURER 610
C-4 BLOCK DIAGRAM OF EXAMPLE 4 - INVESTMENT
CASTING PLANT 620
C-5 COMBINED WASTESTREAMS FOR EXAMPLE 5 -
MALLEABLE IRON PLANT 624
JCVil
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SECTION I
SUMMARY AND CONCLUSIONS
This document presents the technical rationale for effluent
limitations guidelines and standards for the metal molding and
casting point source category as required by the Clean Water Act
of 1977 {P.L. 95-217, "the Act") and the Settlement Agreement in
Natural Resources Defense Council., Inc. v. Train,, 8 IRC 2120
(D.D.C. 1976), modified, 12 ERC 1833 (D.D.C. 1979), modified by
Orders dated October 26, 1982, August 2r 1983, January 6, 1984,
July 5, 1984, and January 1, 1985, This document describes the
technologies which form the bases for effluent limitations
guidelines reflecting the best practicable control technology
currently available (BPT) and the best available technology
economically achievable (BAT), new source performance standards
(NSPS), and pretreatment standards for new and existing sources
(PSNS and PSES).
Effluent limitations guidelines based on the application of BPT
and BAT are to be achieved by existing direct dischargers. New
source performance standards (NSPS) based on the best available
demonstrated technology are to be achieved by new direct
discharging facilities. Pretreatment standards for existing and
new sources (PSES and PSNS) are to be acheived by indirect
dischargers for those pollutants which are incompatible with or
not susceptible to treatment in a publicly owned treatment works
(POTW). These guidelines and standards are required by Sections
301, 304, 306, and 307 of the Clean Water Act.
On November 15, 1982 at 47 FR 51512, the Agency proposed
regulations for six subcategories and 19 process segments of the
metal molding and casting point source category. Following
receipt and evaluation of public comments on these proposed
regulations, the Agency published a notice of availability on
March 20, 1984 at 49 FR 10280 concerning its intended
modifications to or confirmations of the underlying facets of the
proposed regulations. Following receipt and evaluation of public
comments on this notice, the Agency published a second notice of
availability on February 15, 1985 at 50 FR 6572 in which it
summarized the major issues raised in comments on the first
notice and requested additional specific information, In
summary, these three publications explain how the final
regulations supported by this document were developed.
For the purpose of establishing BPT, BAT, NSPS, PSES, and PSNS
for the metal molding and casting category, EPA developed a
subcategorization and process segmentation scheme. In developing
this scheme, the Agency considered numerous factors:
-------
1. Type of metal cast
2. Manufacturing process and water use
3. Air pollution sources
4. Pollutant concentrations in raw wastewater
5. Raw materials
6. Process chemicals
7. Plant size
8. Plant age
9. Geographic location
10. Central treatment
11. Make-up water quality
The type of metal cast is the principal factor affecting the
Agency's subcategorization scheme. Differences in the physical
and chemical properties of the various types of metals cast can
result in differences in manufacturing processes, raw materials,
process chemical use, sources of air pollution, water use, and
process wastewater characteristics. The type of process employed
can also effect wastewater characteristics and water use.
Following an analysis of all the data and information submitted
on the Agency's proposed regulations, the Agency expanded its
subcategorization scheme as explained in the March 20, 1984,
notice of availability of new information (49 FR 10280). The
Agency's final subcategorization scheme includes five
subcategories and 31 process segments. This scheme is as
follows:
Aluminum Casting Subcategory
1. Casting cleaning
2* Casting quench
3. Die casting
4. Dust collection scrubber
5. Grinding scrubber
6. Investment casting
7. Melting furnace scrubber
8. Mold cooling
Copper Casting Subcategory
1. Casting quench
2. Direct chill casting
3. Dust collection scrubber
4. Grinding scrubber
5. Investment casting
6. Melting furnace scrubber
7. Mold cooling
-------
Ferrous Casting Subcategory
1. Casting cleaning
2. Casting quench
3, Dust collection scrubber
4. Grinding scrubber
5. Investment casting
6. Melting furnace scrubber
7. Mold cooling
8. Slag quench
9. Wet sand reclamation
Magnesium Casting Subcategory
1. Casting Quench
2. Dust collection scrubber
3. Grinding scrubber
Zinc Casting Subcategory
1. Casting quench
2. Die casting
3. Melting furnace scrubber
4. Mold cooling
For a complete discussion of the subcategorization scheme, see
Section IV of this document.
EPA studied in-plant control and wastewater recycle in the metal
molding and casting category. The Agency also studied various
end-of-pipe technologies to treat the process wastewaters
generated in this point source category, and then identified
model treatment systems as possible technology bases for the
regulation. These technologies included:
Sedimentation
Chemical precipitation and sedimentation
Flocculation
Neutralization
Multimedia filtration
Vacuum filtration
Chemical emulsion breaking
Oil Skimming
Evaporative cooling
Oxidation by potassium permanganate
Activated carbon adsorption
All technologies except activated carbon adsorption are part of
the technology bases of the final regulations.
Model treatment system costs were prepared for each of several
levels of treatment considered in each process segment. Using
these model costs and the information provided in the Data
Collection Portfolios (DCPs) as submitted and updated by
industry, the Agency estimated the compliance cost impact of the
-------
final regulation on the industry. The Agency also estimated the
expected economic impacts of these costs in terms of the number
of potential plant closures, the number of employees affected,
and the impact on price and balance of trade and other
considerations. These results are reported in the economic
impact analysis. (See Economic Impact Analysis of_ Effluent
Limitations and Standards for^ th_e Metal Molding and Casting
Industry,~U.S. EPA, 440/2-85-028,September 1985).
EPA is promulgating final regulations for four of the six
subcategories for which it had proposed regulations. One of the
two subcategories not being regulated, the lead casting
subcategory, was transferred to the battery manufacturing
category. The other subcategory, the magnesium casting
subcategory, is not subject to these final categorical
regulations because the Agency has determined that regulations
based on the technologies considered for this regulation would
not be economically achievable for existing plants in the
subcategory and that the costs of compliance with the regulations
would present a barrier to entry to new plants.
No discharge of process wastewater pollutants is the basis of
final BPT, BAT, NSPS, PSES, and PSNS regulations for three of the
28 regulated process segments of this category. These are the
grinding scrubber process segments of the aluminum, copper, and
ferrous casting subcategories. Final BPT regulations for the
remaining 25 process segments are generally based on high rate
recycle and treatment of the allowed blowdown by oil skimming and
lime precipitation and settling (with emulsion breaking and/or
chemical oxidation, if required). For two process segments, the
aluminum and zinc die casting segments, complete treatment is
within the recycle loop.
As explained in Section X of this document, BAT regulations based
on high rate recycle, oil skimming, lime precipitation and
settling, and filtration are being promulgated for the copper and
zinc subcategories and for the ferrous subcategory except for (a)
plants where steel is the primary metal cast or (b) plants
pouring less than 3,557 tons of metal per year where malleable
iron is the primary metal cast. BAT limitations equal to BPT
limitations are being promulgated for the aluminum casting
subcategory, for direct dischargers in the ferrous subcategory
where steel is the primary metal cast, and for direct dischargers
pouring less than 3,557 tons of metal per year where malleable
iron is the primary metal cast. As explained in Section XI of
this document, BCT regulations for the metal molding and casting
category are not being promulgated at this time.
For the reasons explained in Section XII of this document, EPA is
promulgating NSPS equal to BAT effluent limitations for each
subcategory segment being regulated. As explained in Section
XIII of this document, PSES and PSNS are being promulgated equal
the BAT technology for all subcategories except the ferrous
subcategory for indirect dischargers pouring less than 1,784 tons
of metal per year where gray iron is the primary metal cast. In
-------
this case, PSES and PSNS are based upon the BPT technology.
On the basis of its review of data on raw wastewater
characteristics and taking into account the statutory factors,
EPA is establishing regulations controlling the following
pollutants and pollutant parameters:
pH
Total suspended solids
Oil and Grease
Phenols (4AAPJ
Total toxic organics (PSES/PSNS)
Copper
Lead
Zinc
A list of the pollutants that are regulated for each subcategory
by the BPT and BAT effluent limitations guidelines, NSPS, PSES,
and PSNS is presented in Table 1-1, TTO is defined separately
for each process segment for which toxic organic pollutants are
regulated. The applied flow rates, recycle rates, and discharge
flow rates that form the basis of the final regulations are shown
in Table 1-2. The BPT flow rates also apply to BAT, NSPS, PSES,
and PSNS.
-------
Applicable to:
Subcategory and
Process Segment
Aluminuffi
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
Ferrous
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand Reclamation
TABLE I-I
POLLUTANT PARAMETERS REGULATED
Direct Dischargers Direct and Indirect Dischargers
Characteristic
pH TSS 0*6(3)
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
. _U<
X
X
X
X
X
X
w,
X
X
X
X
X
X
._______NI
X
X
X
X
X
Pollutants
Phenol (I) TTO(
X
X X
X X
3 Discharge of Pol
X
X X
X
X
X X
3 Discharge of Pol
X
X X
X
X
X X
j Discharge of Pol
X
X X
X
X
X X
Toxic Pollutants
2) Copper
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
lead
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
TABLE 1-1
(CONTINUED)
Applicable to:
Subcategory and
CHsehirgtrs Direct and Indirect Dischargers
Characteristic Pollutants Toxic Pollutants
X
X
X
X
x
X
X
X
X
X X
X X
X
X
X
X
X
X
X
X
X
X
X
x
X
X
X
X
X
X
X
X
X
Z1nc
Casting Quench
Die Casting
HeHIng Furnace
Scrubber
Mold Cooling
{1} Total Phenols - Phenol as measured by the 4 amlnoantlpyrene method - 4AAP
(2) TTO - Total Toxic Qrganlcs measured as the sum of all toxic organic compounds found
in treatable concentrations. See Appendix A for lists of the specific toxic organics
Included in TTO for each subcategory segment. Limitations for TTO are established
only for PSES and PSNS.
(3) Oil and Grease may be used as an alternate monitoring parameter for TTO by indirect
dischargers,
-------
Table 1-2
APPLIED FLOW RATES, RECYCLE RATES, AND DISCHARGE RATES THAT FORM THE BASIS
OF BPT, BAT, NSPS, PSES, AND PSNS
gubcat-egory/PrQcesa
Aluminum
Casting Cleaning
Casting Quench
Die Casting
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace Scrubber
Mold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace Scrubber
Hold Cooling
Ferrous
Casting Cleaning
Casting Quench
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace Scrubber
Production
Norna!ized
AUK]led Flov Rate
H80 gal/ton
115 gal/ton
11,1 gal/ton
K78 gal/1,000 SCF
0.063 gal/1,GOO SCF
IT,600 gal/ton
11.7 gal/1,000 SCF
1,850 gal/ton
»(78 gal/ton
5,780 gal/ton
«,29 gal/1,000 SCF
0.111 gal/1,000 SCF
1ff600 gal/ton
7.04 gal/1,000 SCF
2,450 gal/ton
213 gal/ton
571 gal/ton
3.0 gal/1,000 SCF
3-1? gal/I,000 SCF
IT,600 gal/ton
10.5 gal/1,000 SCF
Production
Normalizing Recycle
Parameter Bate
ton of mo(,al poured 951
ton of metal poured 981
ton of metal poured 95J
UDOO SCF of air 98J
flow through the
scrubber
1,000 SCF of air 100*
flow through the
scrubber
ton of metal poured 659
1,000 SCF of air 961
flow through the
scrubber
ton of metal poured 95%
ton of metal poured 981
ton of metal poured 959
1,000 SCF of air 98J
flow through the
scrubber
t.OOO SCF of air 100J
flow through the
scrubber
ton of metal poured 85J
1,000 SCF of sir 96%
flow through the
scrubber
ton of metal poured 95J
ton of metal poured 95f
ton of metal poured 981
1,000 SCF of air 97*
flow through the
scrubber
1,000 SCF of air 1001
flow through the
scrubber
ton of metal poured 851
1,000 SCF of sir 96>
flow through the
scrubber
Production
normalized
Discharge Flow*
fl.Q gal/ton
2.90 i»l/ton
2.07 gal/ton
O.OJ6 gal/1,000
SCF
0
2,640 gal/ton
0.168 gal/1,ODO
SCF
92,5 g»l/ton
9,56 gal/ton
289 gal/ton
0.086 gal/1,000
SCF
2,610 gal/ton
0,282 gal/1,000
SCF
122 gal/ton
10.7
11.1) gal/ton
0.090 gal/1,000
SCF
0
2,610 gal/ton
0,120 gal/1,000
SCF
-------
Table 1-2 (Continued)
APPLIED FLOW RATES, RECYCLE RATES, AND DISCHARGE RATES THAT THE BASIS
OF BPT, BAT, NSPS, PSES, AND PSNS
Subcategorv/Process Segment
Ferrous (Cont. )
Hold Cooling
Slag Quench
Wet Sand Reclamation
Zinc
Casting Quench
Die Casting
Melting Furnace Scrubber
Hold Cooling
Production
Nornalized
Applied Flow Rate
?0? gal/ton
727 gal/ton
895 gal/ton
533 galAon
41.4 gal/ton
6.07 gal/1,000 SCF
1,890 gal/ton
Production
Normalizing
Paraateter
ton or metal poured
ton oT metal poured
ton of sand reclaimed
ton or octal poured
ton of octal poured
1,000 SCF of atr
flow through the
scrubber
ton of metal poured
Recycle
Rate
95$
94t
80S
981
951
961
951
Production
Normalized
Discharge Floti*
35.1 gal/ton
H3.& gal/ton
179 gal/ton
10.7 gal/ton
2.07 gal/ton
0.2H3 gal/1,000
SCF
91.5 gal/ton
-------
-------
SECTION II
RECOMMENDATIONS
EPA has established final effluent limitations guidelines and
standards for 28 process segments in four subcategories of the
metal molding and casting category. These process segments are
listed in the tables included in this section.
The BPT and BAT effluent limitations guidelines and NSPS for
direct dischargers presented at proposal and in the two notices
of availability assumed that discharges from metal molding and
casting plants would always be on a continuous basis,
Information submitted in comments and confirmed by EPA indicate
that treatment is commonly done on a batch basis with discharge
on an intermittent basis. Consequently, EPA is establishing
final regulations covering both continuous and intermittent
dischargers. Intermittent or non-continuous dischargers are
defined as plants which do not discharge pollutants during
specific periods of time for reasons other than treatment plant
upset, such periods being at least 24 hours in duration. Final
BPT, BAT, and NSPS regulations covering continuous discharges are
found in Tables II-l, II-3, and II-5, respectively. Final BPT,
BAT, and NSPS regulations covering non-continuous discharges are
found in Tables II-2, II-4, and II-6, respectively.
The PSES and PSNS for indirect dischargers, presented in Tables
II-7 and II-8, respectively, cover continuous discharges j>nly.
POTWs may^ elect to establish concentration-based standards for
discharges to POTWs, including non-continuous discharges. They
may do so by establishing concentration-based pretreatment
standards equivalent to the mass-based limitations and standards
found in Tables II-l, II-3, and II-5. Equivalent concentration
standards may be established by multiplying the mass limitations
and standards included in the tables by an appropriate
measurement of average production, raw material usage, or air
flow (kkg of metal poured, kkg of sand reclaimed, or standard
cubic meters of air scrubbed) and dividing by an appropriate
measure of average discharge flow to the POTW, taking into
account the proper conversion factors to ensure that the units
(mg/l) are correct.
11
-------
TA8LE II-1
BPT LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
TSS
Coper Lead Zm
Subcategory and
Al umi num
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
Direct Chill
Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
30-Day
Max.
1.50
.182
.13
4.51
165
58.6
5.79
0.598
18.1
10.8
165
35.3
7.63
Daily
Max.
3.80
.46
.33
11.4
419
148
14.7
1.52
45.8
27.3
419
89.4
19.3
30-Day Dai ly
Max. Max.
1.0
.121
.0864
3.0
110
39.1
3.86
0.399
12.1
7.18
110
23.5
5.09
3,0
.363
.259
9.01
330
117
11.6
1.2
36.2
21.5
330
70.6
15.3
30-Day
Max.
(3)
(3)
.0026
.09
Wn
(3)
1,17
(3)
(3)
(3)
0.215
tin
(3)
0.706
•(3}
Daily 30-Day
Max, Max.
(3) .0421
(3) .0051
.0074 .0036
.258 .126
"Daily 30-Day
Max. Max.
.0771
.0093
.0066
.231
Discharge of Pollutants
(3) 4.63
3.36 1.64
(3) .162
(3) .168
(3) 0.506
0.617 0.301
Discharge of Pol
(3) 4.63
2.02 0.988
(3) D.214
8,48
3.01
.297
,0307
0.928
0.553
lutants
8.48
1.81
0.392
.039
.0047
.0034
.117
4.3
1.52
,151
.0156
0.47
0.28
4,3
0.918
0.199
Daily
Max.
.0791
.0096
.0068
,237
8.7
3.09
,305
.0315
0.952
0.567
8.7
1.86
0.402
30-Day Daily
Max. Max. pH
.0431
,0052
.0037
.129
4.74
1,68
.166
.0171
0.518
0.309
4.74
1.01
0.219
.114 (2)
.0138 (2)
.0098 (2)
.343 (2)
12.6 (2)
4.45 (2)
.44 (2)
.0455(2)
(2)
1,37
0.818 (2)
12.6 (2)
2,68 (2)
0.58 (2)
* All limitations are in units of kg/lOOD kkg (Ib per million Ib) of metal poured except for the Wet Sand
Reclamation, Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter
two process segments, the limitations are in units of kg/62.3 million Sm^ (lb per billion SCF) of air scrubbed;
in the case of the former process segment, the limitations are in units of kg/1000 kkg {Ib per million Ib) of
sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Hot regulated at BPT for this process segment.
-------
TABLE II-l (Continued)
BPT LIHITATIQNS* COVERING CONTINUOUS DIRECT DISCHARGES
TSS
Subcategory and
Process Segment
Ferrous
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Mold Cooling
30-Day
Mai.
0.67
0.713
11.3
165
S2.6
2,22
2.73
11.2
0.67
0.13
30.4
i.il
Daily
Hax.
1.7
1.81
28.5
419
133
5.61
6.91
28.4
1.7
.328
77.1
15
Oil 4 Grease
30-Day Daily
Hax. Max,
0.446 1.34
0.476 1.43
7.51 22.5
110 330
35 101
1.48 4.43
1.82 5.46
7.47 22.4
0,446 1,34
0.0864 0.259
20.3 60.8
3,94 11,8
Phenols(l)
30-Day
Max.
(3)
(3)
0.225
Nr,
(3)
1.05
(3)
(3)
0.224
(3)
Daily
Max.
£3}
(3)
0.656
Discharge
(3)
3.01
(3)
(3)
0.642
(3)
0.0026 0.0074
0.608
(3)
1.74
(3)
Copper Lead
30-Day
Max,
0.0071
0.0076
0.12
of Poll
1.76
0.561
0.0236
0.0291
0.12
0.0187
0.0036
0.852
0.166
Daily 30-Day
Max. Max.
0.0129 0.0174
0.0138 0.0185
0.218 0.293
3.19 4.3
1.02 1.37
0.0428 0.0576
0.0527 0.0709
0.217 0.291
0.0344 0.0174
0.0066 0.0034
1.56 0.791
0,304 0.154
Daily
Max.
0.0353
0.0376
0.593
8.7
2.77
0.117
0.144
0.59
0.0353
0.0068
1.6
0.311
Zinc
30-Day
Max.
0.025
0.0266
0.421
6.17
1.96
0.0827
0,102
0.418
0.0192
0.0037
0.872
0.17
Daily
Max.
0.0656
0.0699
1.1
16.2
5.15
0,217
0.267
1.1
0.0509
0.0098
2.31
0,449
M
(2)
(2)
(2)
(2)
(2)
(2)
{2}
(2)
(2)
(2)
{2}
* All limitations are in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Met Sand
Reclamation, Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter
two process segments, the limitations are in units of kg/62.3 million Sm^ (Ib per billion SCF) of air scrubbed;
in the case of the former process segment, the limitations are in units of kg/1000 kkg {Ib per million lb) of
sand reel aimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) yithin the range of 7.0 to 10.0 at all times
(3) Not regulated at BPT for this process segment.
-------
TABLE 11-2
BPT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Subcategory and
Process Segment
Aluminum
Castinc leaning
Casting uench
Die Casting
Dust Collection
Scrubber
Investment Casting
MeHi'ng Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
TSS
3D-Day
Max,
15(12/x)
15(1. 45/x)
J5(l-04/x)
15(.036/y)
15(1320/x)
15{.468/y)
15(46. 3/x)
15(4. 8/x)
15(145/x)
15(.OB6/y)
15{1320/x)
15{.282/y)
15{61/x)
Daily
Max.
38(12/x)
38(1. 45/x)
38(1. 04/x)
38{.036/y)
38{1320/x)
38(.468/y)
38(46. 3/x)
3S(4.S/x)
38{145/x)
38(.086/y)
38(1320/x)
38{.282/y)
38{61/x)
Oil « Gre
30-Day
Max.
10{12/x)
10(I.45/x)
10(1. 04/x)
10{.036/y)
10{1320/x)
10(. 468/y)
10(46. 3/x)
10(4.8/x)
10(l45/x)
10(.086/y)
10{1320/x)
10{.282/y)
10(61/x)
;ase
Daily
Max.
30(12/x)
30(1. 45/x)
30(2. 04/x)
30( .036/y)
nf PnT 7 uf'anf e-
30(1320/x)
30 ( .468/y)
30(46. 3/x)
30{4.8/x)
30(145/x)
30(.086/y)
ri-f PA! 1 rrf arit'e..
30(1320/x)
30(.282/y)
30(61/x)
Phenol s|
30-Day
Max,
(3)
(3)
0.3(1. 04/x)
0.3(.036/y}
(3)
0.3(. 468/y)
(3)
(3)
(3)
0.3(.086/y)
(3)
0.3(.282/y)
(35
:D
Daily
Max.
(3}
(3)
.85(1. 04/x)
.8S(.036/y)
(3)
.86( .468/y)
(3)
{3}
(3)
.86( .086/y)
(3)
,86{.282/y)
(3)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg (Ib per minion ]b) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the annual average limitations are in units of kg/62.3 million Sm^ (Ib per billion SCF) of air
scrubbed; in the case of the former process segment, the limitations are in units of kg/1000 kkg (Ib per
million Ib) of sand reclaimed.
(!) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at BPT for this process segment.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific
plant.
Y = Actual normalized process wastewater flow (in gallons per 1.000 SCF of air scrubbed) for the specific
plant.
-------
TABLE 11-2 (Continued)
BPT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Subcategory and
P_roce_s_s_ Segment
Alumi num
Casting Cleaning
Casting Quench
Di e Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
30-Day
Max.
.42(12/x)
,42(1.45/x)
.42(1. 04/x)
"Daily
Max.
30- Day
Hax.
Daily
Max,
Zinc
30-Day
Hax.
Daily
Max.
.77{12/x) .39{12/x) .79(12/x) .43{12/x)
.77(!.45/x) .39(1.4S/x) .79(1. 45/x) .43(1.45/x)
.77(1. 04/x) .39(1. 04/x) .79(1. 04/x) .43(1. 04/x)
.42(.036/y) ,77(.036/y) .39{.036/y) ,79{.036/y) .43{.036/y)
------------------------- Mo Discharge of Pollutants
.42(1320/x) .77{1320/x) .39(1320/x) .79(1320/x) .43(1320/x)
.42{.468/y) .77{.468/y) ,39{.468/y)
.42(46.3/x) .77(46,3/x) .39(46.3/x)
.42(4.8/x)
.42(145/x)
.42(.086/y)
.42{1320/x)
.42(.282/y)
.42(61/x)
.77<4.8/x)
.77(145/x)
.77(.086/y)
,77(1320/x)
.77(.282/y)
.77(61/x)
.39(4.87x5
.39(145/x)
.79(.468/y) .43{.468/y)
.79(46.3/x) .43(46.3/x)
.79(4.8/x) .43(4.8/x)
.79{145/x) .43(145/x)
(2)
1.14(1.45/x) (2)
1.14(1.04/x) (2)
1.14(.036/y) (2)
1.14(1320/x) (2)
1.14(.468/y) (2)
1,14(46.3/x) (2)
1.14(4.8/x)
1.14(145/x)
.39(.086/y) ,79{.086/y) .43{.086/y)
No Discharge of Pollutants
.39(1320/x) .79{1320/x) .43(1320/x)
.39(.282/y} .79(.282/y} .43(.282/y)
.39(61/x) .79(61/x) .43{61/x)
(2)
(2)
1.14(.086/y) (2)
1.14{1320/x) (2)
1.14(.282/y) (2)
(2)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Oust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two
process segments, the annual average limitations are in units of kg/62.3 million Sm^ {Ib per billion
SCF) of air scrubbed; in the case of the former process segment, the limitations are in units of kg/1000
kkg (Ih per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at PPT for this process segment.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific
pi ant.
Y = Actual normalized process wastewater flow (in gallons per 1.000 SCF of air scrubbed) for the specific
plant.
-------
TABLE I1-2 (Continued)
BPT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT HASTEWATER DISCHARGES
Suhcategory and
PJXK: es^_Segment
Ferrous
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grindi ng Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Mold Cooling
JSS CK1 & Grease
30-Day Daily 30-Day" Daily
Max. Max. Max. Max.
Phenol sjjlj
30-Day ~ Daily
Max. Hax.
15(5. 35/x)
15(5. 7/x)
15(.09/y)
15(1320/x)
15(.42/y)
15(17. 7/x)
15(21. 8/x)
38(5. 35/x)
38(5. 7/x)
38(.09/y)
38(1320/x)
38(.42/y)
38(17. 7/x)
38(21. 8/x)
10(5. 35/x)
10(5. 7/x)
10(.09/y)
10(1320/x)
10( ,42/y)
10(17. 7/x)
10(21. 8/x)
30(5. 35/x)
30(5. 7/x)
30(.09/yJ
30(1320/x)
30(.42/y)
30(17. 7/x)
30(21. 8/x)
(3)
(3)
.3(.09/y)
(3)
.3(.42/y)
(3)
(3)
(3)
(3)
.86(.09/y)
(3)
.86(.42/y)
(3)
(3)
15(89.5/z) 38(89.5/z) 10(89.5/z) 30(89.5/z) .3(89.5/z) .86(89.5/z)
15(5.35/x)
15(1.04/x)
15(.243/y)
15(47,3/x)
38(5.35/x)
38(1.04/x)
38(.243/y)
38(47.3/x)
10(5,35/x)
10(1.04/x)
10(.243/y)
10(47.3/x)
30(5.35/x)
30(1.04/x)
30(.243/y)
30(47.3/x)
(3)
.3(1.04/x)
.3(.243/y)
(3)
(3)
.86(1.04/x)
.86(.243/y)
(3)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations
are in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter
two process segments, the annual average limitations are in units of kg/62.3 million Sm3 (fb per
billion SCF) of air scrubbed; in the case of the former process segment, the limitations are in units
of kg/1000 kkg (Ib per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP),
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at BPT for this process segment.
X = Actual normalized process wastewater flow (in gallons per 1.000 pounds of metal poured) for the specific
plant.
Y = Actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific
plant.
Z = Actual normalized process wastewater flow (in gallons per 1,000 pounds of sand reclaimed) for the
specific plant.
-------
BPT
TABLE 11-2 (Continued)
LIHITATIONS* COVERING NON-CONTINUOUS DIRECT NASTEWATER DISCHARGES
Subcategory and
Process Segment
Ferrous
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Mold Cooling
Coj)pe_r
30-Day "' " "Daily
Max. Max*
Lead Zinc
30-Day ~ ~ Daily 30-Day" ~ Daily
Max. Max, Max, Max.
.16(5. 35/x)
.16(5. 7/x)
.16(.09/y)
.16{1320/x)
.16(.42/y)
.16(17. 7/x)
.16(21. 8/x)
.29(5. 35/x)
.29(5. 7/x)
.29(.09/y)
.29(1320/x)
.29(.42/y)
.29(17. 7/x)
.29(21. 8/x)
.39(5. 35/x)
.39(5. 7/x)
-39(.09/y)
-No Discharge
.39(1320/x)
.39(.42/y)
,39(17. 7/x)
.39(21. 8/x)
.79(5. 35/x)
.79(5. 7/x}
.79(.09/y)
of Pollutant!
,79(1320/x)
.79(.42/y)
.79(17. 7/x)
.79(21. 8/x)
.56(5, 35/x)
.56(5. 7/x)
.56(.09/y)
.56{1320/x)
.56(,42/y)
.56(17. 7/x)
.56(21 .8/x)
1
1
1
1
1
1
1
.47(5. 35/x)
.47(5. 7/x)
.47{.09/y)
.47(1320/x)
.47(.42/y)
.47(17, 7/x)
.47(21. 8/x)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
.16(89.5/z) .29(89.5/z) .39(89.5/z) .79(89.5/z) .56(89.5/z) 1.47(89.5/z) (2)
.42(5.35/x) .77(5.35/x) .39(5.35/x)
.42(1.04/x) .77(1.04/x) .39(1.04/x)
.42{.243/y) .77(.243/y) .39(.243/y)
.42(47.3/x) .77(47.3/x) .39(47.3/x)
.79(5.35/x) .43(5.35/x)
.79(1.04/x) .43(1.04/x)
.79(.243/y) ,43(.243/y)
.79(47.3/x) .43(47.3/x)
1,14(5.35/x) (2)
1.14(1.04/x) (2)
1.14(.243/y) (2)
1.14(47.3/x) (2)
(1)
(2)
(3)
X -
All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two
process segments, the annual average limitations are in units of kg/62.3 million Sra3 (I
SCF) of air scrubbed; in the case of the former process segment, the limitations are in
kkg (Ib per million Ib) of sand reclaimed.
Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
Within the range of 7.0 to 10. 0 at all times.
per billion
units of kg/1000
Not regulated at BPT for this process segment
Actual
plant.
Y - Actual
plant.
Z = Actual normalized process wastewater flow (in gallons per 1,000 pounds of sand reclaimed) for the
normalized process wastewater flow (in gallons per
normalized process wastewater flow (in gallons per
1,000 pounds of metal poured) for the specific
1.000 SCF of air scrubbed) for the specific
specific plant.
-------
TABLE I1-3
BAT LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
Suhcategory and
_Proces_s Segment
Aluminum
Casting Cleaning
Casting Quench
Die Casting
Oust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Phenojs(l)
30-Day "Da Fly
Max. Max.
Copper
30-Oay 'Daily
Max. Max.
Lead
30-Day ""Daily
Max. Max.
(3)
(3)
.0026
.09
{3)
1.17
(3)
(3)
(3}
.0074
.258
(3)
3.36
(3)
.0421
.0051
.0036
.126
4.63
1.64
.162
.0771
.0093
,0066
.039
.0047
.0034
.231 .117 .2
Discharge of Pollutants
8.48 4.3 8.7
(3)
(3)
.215
(3)
.706
(3)
(3)
(3)
.617
(3)
2.02
(3}
.0
.5
.3
4.6
.9
.2
3.01
.297
.0307
.928
1.52
.151
.0104
.314
3.09
01 .553 .187 .3
No Discharge of Pollutants
3 8.48 2.86 5.84
1.81
.392
.612
.132
1.25
.
30-Oay
Max.
-
Daily
Max.
pH
791 .0431
096 .0052
068 .0037
37 .129
4.74
9 1,68
05 .166
.114
.0138
.0098
.343
12.6
4.45
.44
{2}
(2)
(2)
(2)
(2)
(2)
{2}
211 .0116
39 .35
8 ,208
4 3.19
5 .673
7 .148
.0303
.916
.545
8.37
1.79
.387
{2}
(2)
(2)
(2)
(2)
(2)
* All limitations are in units of kg/1000 kkg (lb per million lh) of metal poured except
for the Wet Sand Reclamation, Dust Collection Scrubber, and Melting Furnace Scrubber
process segments. In the case of the latter two process segments, the limitations are in
units of kg/62.3 million Sm3 (lb per billion SCF) of air scrubbed; in the case of the
former process segment, the limitations are in units of kg/1000 kkg {lb per million lb)
of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-annnoantipyrene method {4AAP}.
(?.) Within the range of 7.0 to 10.0 at all times.
{3} Not regulated at BAT for this process segment.
18
-------
TABLE II-3 (Continued)
BAT LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
Subcategory and
PhenoJ_s (1)
30-Day" DaTly 30-Day
Max. Max, Max.
Lead
"O'aily 30-Day ""Daily
Max. Max, Max,
30-Day"
Daily
Max.
Ferrous(4)
Casting Cleaning
Casting Quench
Oust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
Slag Quench
Wet Sand
Reclamation
Ferrous{5)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
(3)
{3}
.225
(3)
1.05
(3)
(3)
(3)
(3)
.646
(3)
3.01
(3)
(3)
.0
.0
.1
1.7
.5
.0
.0
,0129 .0116 .0237 .0165 ,0437 (2)
.0138 .0124 ,0252 .0176 .0466 (2)
.278
2 .218 .195 .398
No Discharge of Pollutants
6 3.19 2.86 5.84 4.D7
.736
10,8
.224
(3)
(3)
.225
(3)
1.05
(3)
(3)
.224
.642
{3}
(3)
.656
(3)
3.01
{3}
(3)
.642
.12
.217
.194
.396
.276
.561 1.02 1,37 2.77
.0236 .0428 .0576
.0291 .0527 .0709
.12
.217
.291
.59
.418
1.1
(2)
"(2)
1.02 .911 1.86 1.3 3.44 (2)
.0428 .0384 .0783 .0546 .145 (2)
.0527 .0473 .0964 .0673 .178 (2)
.732 (2)
.0071 .0129 .0174 .0353 .025 .0656 (2)
.0076 .0138 .0185 .0376 .0266 .0699 (2)
.12 .218 .293 .5
No Discharge of Pollutants
1.76 3,19 4.3 8.7
33 .421
6.17
7 1.96
17 .0827
44 .102
1.1
16.2
5.15
.217
.267
(2)
(2)
(2)
{2}
(2)
(2)
* All limitations are in units of kg/1000 kkg {lb per million lb) of metal poured except
for the Wet Sand Reelamation. Dust Collection Scrubber, and Melting Furnace Scrubber
process segments. In the case of the latter two process segments, the limitations are
In units of kg/62.3 million Stn3 (lb per billion SCF) of air scrubbed; in the case of the
former process segment, the limitations are in units of kg/1000 kkg (lb per million Ib)
of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoant1pyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at BAT for this process segment.
(4) Applicable to plants that cast primarily malleable iron where greater than 3,557 tons of
metal are poured per year and to plants that cast primarily ductile or gray iron.
19
-------
Subcategory and
TABLE II-3 (Continued)
BAT LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
P_hejlol^U^
Max. Max.
Ferrous{4)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
FerrousfS)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
Cogper
30-0~ay "0811 y
Max. Max.
_L_e_ad Z1nc
30-Day Daily 30-Day Daily
Max. Max. Max. Max.
{3}
(3)
.225
(3)
1.05
(3)
(3)
(3)
(3)
.646
(3)
3.01
(3)
(3)
.0
.0
.1
1.7
.5
.0
.0
.0129
.0138
.0116
.0124
2 ,218 .195
No Discharge of Pollutants
6 3.19 2.86
.224
(3)
(3)
.225
"(3)""
1.05
(3)
(3)
.224
.642
(3)
(3)
.656
"(3)"
3.01
(3)
(3)
.642
0291
,12
.0071
.0076
1.02
.0428
.0527
.911
.0384
.0473
.0237
.0252
.398
ntQ----
5.84
1.86
.0783
.0964
.0165
.0176
.278
4.07
1.3
.0546
.0673
.0437
.0466
.736
10.8
3.44
.145
.178
(2)
(2)
(2)
(2)
(2)
(2)
(2)
.217 .194
.396
.276
.732 (2)
.0129
.0138
.0174
.0185
.12 .218 .293 .5
No Discharge of Pollutants
1.76 3.19 4.3 8.7
.561
.0236
.0291
.12
1.02 1.37
.0428 .0576
.0527 .0709
.217
.291
2.77
.59
353 .025
376 .0266
93 .421
6.17
7 1.96
17 .0827
44 .102
.0656
.0699
1.1
16.2
5.15
.217
.267
(2)
(2)
(2)
(2)
(2)
(2)
(2)
.418
1.1
(2)
(1)
(2)
(3)
(4)
(5}
All limitations are in units of kg/1000 kkg (Ib per million lb} of metal poured except
for the Wet Sand Reclamation, Dust Collection Scrubber, and Melting Furnace Scrubber
process segments. In the case of the latter two process segments, the limitations are
in units of kg/62.3 million Sm3 (lb per billion SCF) of air scrubbed; 1n the case of the
former process segment, the limitations are in units of kg/1000 kkg (Ib per million lb)
of sand reclaimed.
Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
Within the range of 7.0 to 10.0 at all times.
Not regulated at BAT for this process segment.
Applicable to plants that cast primarily malleable iron where greater than 3.557 tons of
metal are poured per year and to plants that cast primarily ductile or gray iron.
Applicable to plants that cast primarily malleable iron where equal to or less than
3,557 tons of metal are poured per year and to plants that cast primarily steel.
20
-------
Subcategory and
Process Segment
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Mold Cooling
TABLE II-3 (Continued)
BAT LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
PjienoVsJ 1_^
30-Day Daily
Max. Max.
(3)
.0026
.608
(3)
(3)
.0074
1.74
(3)
30-Day
Nax.
.0187
.0036
.852
.166
_ Le^ Z]i
"D'aily 30-Day "Oaily 30-Oay
Max, Max. Max. Max.
,0344 .0116
.0066 .0022
1.56
.304
.527
.103
.0237
,0046
1.07
,209
.0129
.0025
.588
.114
"Daily
Max.
1.54
.3
PJl
.0339 {2}
.0066 (2)
(2)
(2)
* All limitations are in units of kg/1000 kkg {Ib per million Ib) of metal poured except
for the Wet Sand Reclamation, Dust Collection Scrubber, and Melting Furnace Scrubber
process segments. In the case of the latter two process segments, the limitations are
in units of kg/62.3 million Sm^ (Ib per billion SCF) of air scrubbed; in the case of the
former process segment, the limitations are 1n units of kg/1000 kkg {Ib per million Ib)
of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at BAT for this process segment.
21
-------
Subcategory and
Process^Segment
Alumi num
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
Di rect Chill Casting
•j Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
TABLE II-4
BAT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT MASTEWATER DISCHARGES
Phenolsj[l}
30-Day' Daily
Max. Max.
Copper
30-Day "Daily
Max, Max.
Lead
30-Day " Daily
Max, Max,
(3) (3) .42{12/x) .77{12/x) ,39(12/x) .79(12/x)
{3} (3) .42{1.45/x) .77(1.45/x) .39(1.45/x) .79(1.45/x)
,3{1.04/x) ,86{l.D4/x).42(1.04/x) .77(1.04/x) ,39(1.04/x) ,79{1.04/x)
.3(.D36/y) ,86(.036/y).42(.036/y) .77{.036/y) .39(.036/y) .79(,036/y)
No Discharge of Pollutants
(3) (3) .42{1320/x) .77{I320/x) .39(1320/x) .79(1320/x)
.3(,468/y) ,86(.468/y).42(,468/y) ,77(.468/y) ,39(.468/y) ,79(,468/y)
{3} {3} .42(46,3/x) .77(46,3/x) .39(46.3/x) .79(46.3/x)
Zinc
30-Day " Daily
Max. Max,
,43{12/x) 1.14(12/x)
.43(1.45/x) l,14(
.43(1.04/x) 1.14(1
(2)
(2)
(2)
.43( ,036/y) 1.14(.036/y) (2)
.43(1320/x) 1.14{1320/x) (2)
.43{.468/y) 1.14(,468/y) (2)
.43(46. 3/x) 1,14(46. 3/x) (2)
(3)
(3)
.3(.086/y)
(3)
.3(.282/y)
(3)
(3)
(3)
.86(
(3)
,86(
(3)
,42(4.8/x)
.42(145/x)
.D86/y).42{.086/y)
,42(1320/x)
.282/y).42{.282/y)
.42(61/x)
.77(4.8/x)
.77(I45/x)
.77(,086/y)
-No Discharge
,77(1320/x)
.77(.282/y)
.77(61/x)
.26(4.8/x)
.26(145/x)
.26{.086/y)
of PollutaT
.26(1320/x)
.26(,282/y)
.26{61/x)
.53{4,8/x)
,53(145/x)
,53(.086/y)
its - ~
,53(1320/x)
.53(.282/y)
,53(61/x)
,29(4.8/x)
.29(145/x)
,29(.086/y)
,29(1320/x)
.29(.282/y)
,29(61/x)
.76(4.8/x)
,76(l45/x)
,76(.D86/y)
,76(1320/x)
.76(.282/y)
.76(61/x)
(2)
(2)
(2)
(2)
(2)
(2)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are in units
of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust Collection Scrubber,
and Melting Furnace Scrubber process segments. In the case of the latter two process segments, the annual average
limitations are in units of kg/62.3 million Sm3 (Ib per billion SCF) of air scrubbed; in the case of the former
process segment, the limitations are in units of kg/1000 kkg (Ib per million Ib) of sand reclaimed,
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP)
(2) Within the range of 7.0 to 10.0 at all times.
{3} Not regulated at BAT for this process segment.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific plant,
Y = Actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific plant.
-------
Subcategory and
_P roce sji__Se_gment
Ferrous(4)
Casting Cleaning
Casting Quench
Oust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
Slag Quench
Wet Sand
Reelamation
TABLE I1-4 (Continued)
BAT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Phenols(l)
30-Day" Daily
Max. Max.
CopjDer _
30-Oay ~~ Daily 30-Day Daily
Max. Hax. Max. ?1ax.
Zinc
30-Day Daily
Hax. Max.
(3) (3)
(3) (3)
.3(.09/y} .8S(.09/
(3) (3)
.I6(5.35/x) .29(5.35/x).26(5.35/x).53{5.35/x).37{5.35/x).98(5.35/x) (2)
.16(5. 7/x) .29(5. 7/x) .26(5. 7/x) .53{5.7/x) ,37(5. 7/x) .98(5.7/x) (2)
y) .16{.09/y) .29{.09/y) ,26( .09/y) .53(.09/y) ,37(.09/y) .98(.09/y) (2)
.16fl320/x) ,29(1320/x).26{1320/x).53(1320/x).37(1320/x).98(1320/x) (2)
.3(.42/y) ,86(.42/y) .16f.42/y) .29(.42/y) .26(.42/y) .53(.42/y) .37f.42/y)
(3) (3) .16(17.7/x) .29(17.7/x).26(17.7/x).53{17.7/x).37{17.7/x)
(3) (3) .16(21.8/x) .29(21.8/x).26(21.8/x).53(21.8/x).37(21.8/x)
.98(.42/y) (2)
.98(17.7/x) (2)
,98(21.8/x) (2)
.3(89.5/z} .86(89.5/z) .16(89.5/z) .29(89.5/z).29(89.5/z),53(89.5/z).37(89.5/z).98(89.5/z) (2)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are in units
of Vg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust Collection Scrubber,
and Melting Furnace Scrubber process segments. In the case of the latter two process segments, the annual average
limitations are in units of kg/62/3 million Sm3 (Ib per billion SCF) of air scrubbed; in the case of the former
process segment, the limitations are in units of kg/1000 kkg (Ib per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at BAT for this process segment,
(4) Applicable to plants that cast primarily malleable iron where greater than 3,557 tons of metal are poured per
year and to plants that cast primarily ductile or gray iron.
X - Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific plant.
Y = Actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific plant.
Z = Actual normalized process wastewater flow (in gallons per 1,000 of sand reclaimed) for the specific plant.
-------
Subcategory and
Ferrous(5)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Het Sand
Reclamation
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Mold Cooling
TABLE II-4 (Continued)
BAT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Pheno_H(_l_)
30-Day Dai'ly
Max. Max.
(3)
(3)
(3)
(3)
Copper Lead Zinc^
30-Day "Daily 30-Day Daily 30-Day Daily
Max. Max. Max. Max. Max. Max.
.16(5.35/x) .29(5.35/x).39(5.35/x).79(5.35/x).56(5.35/x)l.47(5.35/x) (2)
.16(5.7/x) .29(5.7/x} .39(5.7/x) .79(5.7/x) .56(5.7/x) 1.47(5.7/x) (2)
.3{.09/y) ,86{.D9/y) .16(.09/y) .29(.09/y) .39(.09/y) ,79(,09/y) .56(.09/y) 1.47(.09/y) (2)
Ho Discharge of Pollutants
(3) (3) .lfi{1320/x) .29(1320/x).39(1320/x},79(1320/x).56(1320/x)1.47(1320/x) (2)
.3(.42/y) .86(.42/y) .16f.42/y) ,29(.42/y) .39(.42/y) .79{.42/y) .56(.42/y) 1.47{,42/y) (2)
(3) (3) .16(17.7/x) .29(17.7/x).39{17.7/x).79(17.7/x).56(17.7/x)l.47(17.7/x) (2)
(3) (3) .16(21.fi/x) .29(21.8/x),39(21.8/x).79(21.8/x).56(21.8/x)l»47(21.8/x) (2)
.3(89.5/z) .8fi(89.5/z) .16(89.5/z) .29(89.5/z}.39(89.5/z).79(89.5/z).56(89.5/z)l.47(89,5/z) (2)
(3) (3) .42(5.35/x) .77(5.35/x).26(5.35/x).53(5.35/x).29(5.35/x).76(5.35/x) (2)
.3{1.04/x) ,86(1.04/x) .42(1.04/x) ,77(1.D4/x).26(1,04/x).53(1.04/x),29(1.04/x).76(1.04/x) (2)
.3{.243/y) .8fi(,243/y) .42{.243/y) .77(.243/y}.26(.243/y).53(.243/y).29(.243/y),76(.243/y)
(3) (3) .42(47.3/x) .77(47.3/x).26(47.3/x).53(47.3/x).29(47.3/x).76(47.3/x)
(2)
(2)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are in units
of kg/1000 klcg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust Collection Scrubber,
and Melting Furnace Scrubber process segments. In the case of the latter two process segments, the annual average
limitations are in units of kg/62.3 million Si7)3 (lb per billion SCF) of air scrubbed; in the case of the former
process segment, the limitations are in units of kg/1000 kkg (lb per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP),
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at BAT for this process segment.
(5) Applicable to plants that cast primarily malleable iron where equal to or less than 3.557 tons of metal are
poured per year and to plants that cast primarily steel.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific plant,
Y = Actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific plant.
Z = Actual normalized process wastewater flow (in gallons per 1,000 of sand reclaimed) for the specific plant.
-------
TABLE 11-5
NSPS LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
TSS
Oil & Grease
Phenols(l)
Copper
Lead
Zinc
Subcategory and
Process Segment
Aluminum
Casting Cleani ng
Casting Quench
Die Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
He! ting Furnace
Scrubber
Hold Cooling
Copper
Casting Quench
Direct Chill
Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
30-Day
Max.
1.50
.182
.13
4,51
165
58.6
5.79
.479
14.5
8.61
132
28.2
6.11
Daily
Max.
3.80
.46
.33
11.4
419
148
14.7
.598
18.1
10.8
165
35.3
7.63
30- Day
Max.
1.0
.121
.0864
3.0
110
39.1
3.86
.399
12.1
7.18
110
23.5
5.09
Daily
Max.
3.0
.363
.259
9.01
330
11?
11.6
1.2
36.2
21.5
330
70.6
15.3
30-Day
Max.
(3)
(3)
.0026
.09
Wn
(3)
1.17
(3)
(3)
(3)
.215
Wn
(3)
.706
(3)
Daily
flax.
(3)
(3)
.0074
.258
Discharge
(3)
3.36
(3)
(3)
(3)
.617
Discharge
(3)
2.02
(3)
30- Day
Max.
.0421
.0051
.0036
.126
of Pol
4.63
1.64
.162
.0168
.506
.301
of Pol
4.63
.988
.214
Daily
Max.
.0771
.0093
.0066
.231
8.48
3.01
.297
.0307
.928
.553
8.48
1.81
.392
30- Day
Max.
.039
.0047
.0034
.117
4.3
1.52
.151
.0104
.314
.187
2.86
.612
.132
Daily
Max,
.0791
.0096
.0068
.237
8.7
3.09
.305
.0211
.639
.38
5.84
1.25
.27
30- Day
Max.
.0431
.0052
.0037
.129
4.74
1,68
.166
.0116
.35
.208
3.19
.673
.148
Daily
Max. pH
.114 {2}
.0138 (2)
.0098 (2)
.343 (2)
12.6 (2)
4.45 (2)
.44 (2)
.0303(2)
.916 (2)
.545 (2)
8.37 (2)
1.79 (2)
.387(2)
* All limitations are in units of kg/1000 kkg Ob per million lb) of metal poured except for the Wet Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 million Stn^ (lb per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/1000 kkg (lb per million lb) of sand reclaimed.
{1} Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP)
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at NSPS for this process segment.
-------
Subcategory and
P_ro_c e s s__Se_9m_eivt
Ferrous{4)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
TABLE I1-5 (Continued)
NSPS LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
TSS
30-Day ~Daily
Max. Max.
30-Day
Max.
Oafly
Max,
Ph_enpl_sO_}
30-Day Dafly 30-Day
Max. Max. Max.
T lead
Daily 30-Day Daily
Max, Max. Max,
2 trie
30-Day "Dally
Max, Max,
9
132
42
1
2
.536
.571
.01
.1
.77
.18
11
165
52
2
2
.67
.713
.3
.6
.22
.73
7
110
35
1
1
.446
.476
.51
.48
.82
1
I
22
330
105
4
5
,34
,43
.5
.43
.46
(3}
(3)
.225
N
(3)
1.05
(3)
(3)
(3) .0071
(3) .0076
.646 .12
No Discharge of Pollutants
8.96
11.2
7.47
22.4 .224
(3)
3.01
(3)
(3)
.642
1.76
.561
.0236
.0291
.12
.0129
.0138
.218
3.19
1.D2
.0428
.0527
.0116
.0124
.195
2.86
.911
.0384
.0473
.0237
.0252
.398
5.84
1.86
.0783
.0964
.0165
.0176
.278
4.07
1.3
.0546
.0673
.0437
.D466
.736
10.8
3.44
.145
,178
(2)
(2)
(2)
(2)
(2)
(2)
(2)
.217 .194
.396 .276
.732 (2)
* All limitations are in units of kg/1000 kkg (lb per million Ib) of metal poured except for the Wet Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 Sm^ (lb per billion SCF) of air scrubbed; in the case of the
former process segment, the limitations are in units of kg/1000 kkg (Ib per million lb) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP)
{2} Within the range of 7.0 to 10.D at all times.
(3) Not regulated at NSPS for this process segment
(4) Applicable to plants that cast primarily malleable iron where greater than 3,557 tons of metal are poured per year and
to plants that cast primarily ductile or gray iron.
-------
Subcategory and
Ferrous(5)
Casting Cl eaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hoi d Cool ing
Slag Quench
Wet Sand
Reclamation
M Zinc
"""* Casting Quench
Die Casting
Melting Furnace
Scrubber
Mold Cooling
TABLE 11-5 (Continued)
NSPS LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
IS* PtL* Crease P'lf:001 S-1U. _c_°PPeJL i^ld ^iflc
30-Day "Daily 3D"-Day"" Daily 30-Day"~ Daily 30-Day " Daily 3D-Day D~aily 30-Day '"Daily
Hax. Max. Hax. Max. Hax. Hax. Max, Hax. Max. Max. Hax. Max.
11
165
52
2
2
.67
.713
.3
.6
.22
.73
1
1
28
419
133
5
6
.7
.81
.5
.61
.91
7
110
35
1
1
.446
.476
.51
.48
.82
1
1
22
330
105
4
5
.34
.43
.5
.43
.46
(3)
(3)
.221
(3)
1.05
(3)
(3)
(3)
(3)
.0071
.0076
i .656 .12
No Discharge of Pollutants
(3) 1.76
.0129
.0138
.218
rlf t
.19
.0174
.0185
.293
4.3
.0353
.0376
.593
8.7
.025
.0266
.421
6.17
1
16
.0656
.0699
.1
.2
(2}
(2)
(2)
(2)
11.2
.536
.104
24.3
4.73
28.4
.67
.13
30.4
5.91
7.47 22.4
.446
,0864
20.3
3.94
1.34
.259
60.8
11.8
.224
(3)
.002fi
.608
(3)
3.01
(3)
(3)
.642
(3)
.0074
1.74
(3)
.561
.0236
.0291
.12
.0187
.0036
.852
,166
1.02 1.37 2.77 1.96
.0428 .0576 .117 .082?
.0527 .0709 .144 .102
5.15 (2)
.217 (2)
.267 (2)
.217 .291
.0344 .0116
.0066 .0022
.59
.418
1.1
(2)
.0237 .0129
.0046 .0025
.0339 (2)
.0066 (2}
1.56
.304
.527
.103
1.07
.209
.588
.114
1.54
.3
(2)
(2)
* All limitations are in units of kg/1000 kkg (lb per million lb) of metal poured except for the Wet Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 million Sm3 (lb per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/1000 kkg (lb per million lb) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP)
(2) Mithin the range of 7,0 to 10.0 it §11 times
(3) Not regulated at NSPS for this process segment
(5) Applicable to plants that cast primarily malleable iron where equal to or less than 3,557 tons of metal are poured per
year and to plants that cast primarily steel.
-------
TABLE 11-6
NSPS LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEHATER DISCHARGES
Subcategory and
Process Segment
Alumi num
Casting Cleaning
Casting Quench
01e Casting
Dust Collection
Scrubber
Grlndi ng Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
> Direct Chill Casting
* Oust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
TSS
30-Day " Daily
Max. Max.
12(4.8/x)
12(145/x)
12(.086/y)
12(1320/x)
12{.282/y)
12(61/x)
15{4.8/x)
15(145/x)
15(.086/y)
15(132Q/x)
15{.282/y)
15{61/x)
30-0"ay
Max.
15(12/x)
15{1. 4S/x)
15(1. 04/x)
15(.036/y)
15(1320/x)
15{. 468/y)
15(46. 3/x)
38{12/x)
38(1.45/x)
38(1. 04/x}
38( .036/y}
38(1320/x)
38{ .468/y)
38(46. 3/x)
10{I2/x)
10{1.45/x)
10(1. 04/x)
10(. 036/y)
10(1320/x)
10 ( .468/y)
10(46. 3/x)
10{4.8/x)
10(145/x)
10(.086/y)
-No Discharge
10(1320/x)
10(.282/y)
10(61/x)
Daily
Max,
30(12/x)
30(1.45/x}
30(1.04/x)
30(.036/y)
of Pollutants-
30(1320/x)
30(.468/y)
30(46.3/x)
30(4.8/x)
30(145/x)
30(.086/y)
of Pollutants-
30(1320/x)
30(.282/y)
30(61/x)
Phenojs(l)
30-Day Daily
Hax. Max.
(3)
(3}
0.3(1.04/x)
0.3(.036/y)
.....___.
0.3(.468/y)
(3)
(3)
(3)
0.3{.086/y)
....._
0.3(.282/y)
(3)
(3)
(3)
.86(1.04/x)
.86(.036/y)
"(3)
.86(.468/y)
(3)
(3)
(3)
.86(.086/y)
"(3)
.86{.282/y)
(3)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the annual average limitations are in units of kg/62.3 million Sm3 (Ib per billion SCF) of air
scrubbed; in the case of the former process segment, the limitations are in units of kg/1000 kkg (Ib per
million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at NSPS for this process segment.
X = Actual normalized process wastewater flow (in gallons per 1.000 pounds of metal poured) for the specific
plant.
Y * Actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed} for the specific
plant.
-------
TABLE 11-6 (Continued)
NSPS LIMITATIONS* COVERING NON-CONTINUOUS DIRECT HASTEWATER DISCHARGES
Subcategory and
P rocess Segment
Aluminun
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Lead
Zinc
30-Day
Max.
.42(12/x)
.42(1.45/x)
.42(1.04/x)
.42(.036/y)
,42(1320/x)
Daily
Max.
30-Day
Max,
Daily
Max.
30-Day
Max.
Daily
Max.
.77(12/x) .39(12/x) .79(12/x) .43(12/x) 1.14(12/x) (2)
.77(1.45/x) .39(1.45/x) .79(1.45/x) .43(1.45/x) 1.14(1.45/x) (2)
.77(1.04/x) .39(1.04/x) .79(1.04/x) .43(1.04/x) 1.14(1.04/x) (2)
,77{.036/y) .39(.036/y) .79(.036/y) .43(.036/y) 1.14(.036/y) (2)
— - No Discharge of Pollutants-
,77(1320/x) .39(1320/x) ,79(1320/x) .43(1320/x) 1.14(1320/x) (2)
.42(.468/y) .77(.468/y) ,39(.468/y)
.42(46.3/x) .77(46.3/x) .39(46.3/x)
.79(.468/y) .43(.468/y) 1.14(.468/y) (2)
.79(46.3/x) .43(46,3/x) 1.14(46.3/x) (2)
.42{4.8/x)
.42{145/x)
,42(. 086/y)
,42(1320/x)
.42{.282/y)
,42(61/x)
.77(4.8/x)
,77(145/x)
.77(.086/y)
.77(1320/x)
.77(.?82/y)
.77(61/x)
.26(4.8/x)
,26(14S/x)
.26( .086/y)
.26(1320/x)
.26(.282/y)
.26(61/x)
.53(4.8/x)
,53(145/x)
.53(. 086/y)
.53(1320/x)
,53(.282/y)
.53(61/x)
.29(4.8/x)
.29(145/x)
.29 (.086/y)
.29(1320/x)
.29(.282/y)
.29(61/x)
.76{4.8/x)
.76(145/x)
.76(,086/y)
,76(1320/x)
.76{.282/y)
.76(61/x)
(2)
(2)
(2)
(2)
(2)
(2)
* All 30-Day Maximum and Daily Maximum limitations are in rag/1 units. The annual average limitations are
in units of kg/1000 kkg (Ib per million lt>) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two
process segments, the annual average limitations are in units of kg/62.3 million Sm^ (lb per billion
SCF) of air scrubbed: in the case of the former process segment, the limitations are in units of kg/1000
kkg (Ib per million Ih) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at NSPS for this process segment.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific
plant,
Y = Actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific
plant.
-------
TABLE 11-6 (Continued)
NSPS LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Subcategory and
Ferrous(4;
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
SI ag Quench
Wet Sand
Reclamation
TS:
30-Day
Max.
12(5. 35/x)
12(5. 7/x)
12(.09/y)
12(1320/x)
12(.42/y)
12(17. 7/x)
12(21. 8/x)
5
Daily
Max.
15(5. 35/x)
15(5. 7/x)
15{ .09/y)
15(1320/x)
15(.42/y)
15(17. 7/x)
15(21. 8/x)
Oil & Gr«
30-Day
Max.
10(5. 35/x)
10(5. 7/x)
10(.09/y)
10(1320/x)
10(.42/y)
10(17. 7/x)
10(21. 8/x)
»ase
Daily
Max.
30(5. 35/x)
30(5. 7/x)
30( .D9/y)
n€ Pnl 1 ut1 arvFc-
30(1320/x)
30(.42/y)
30(17. 7/x)
30(21. 8/x)
Phenol s
30-Day
Max.
(3)
(3)
-3{.09/y)
(3)
.3(.42/y)
(3)
(3)
(1)
Daily
Max.
(3)
(3)
.86(.09/y)
(3)
.86(.42/y)
(3)
(3)
12(89.5/z) 15(89.5/z) 10(89.5/z) 30(89.5/z) .3(89.5/z) .86(89.5/2)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two
process segments, the annual average limitations are in units of kg/62,3 million Sm3 (Ib per billion
SCF) of air scrubbed: in the case of the former process segment, the limitations are in units of kg/1000
kkg (Ib per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at NSPS for this segment.
(4) Applicable to plants that cast primarily malleable iron where greater than 3,557 tons of metal are
poured per year and to plants that cast primarily ductile or gray iron.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific
plant,
Y = Actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific
pi ant.
Z = Actual normalized process wastewater flow (in gallons per 1.000 pounds of sand reclaimed) for the specific
plant.
-------
TABLE I1-6 (Continued)
NSPS LIMITATIONS* COVERING NON-CONTINUOUS DIRECT HASTEHATER DISCHARGES
Subcategory and
Copjjer
30-Day" ™ Daily 30-Day
Max. Max. Max.
Zinc
Daily
Hax.
30-Day
Hax.
Dally
Hax.
Ferrous(4)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Met Sand
Reclamation
.16(5, 35/x)
.16(5. 7/x)
.16(.09/y)
.16(1320/x)
.16(.42/y)
.15(17. 7/x)
.16(21 .8/x)
.29(5. 35/x)
.29(5. 7/x)
.29{ .09/y)
.29(1320/x)
.29( .42/y)
.29(17. 7/x)
. 29(21. 8/x)
.26(5. 35/x)
.26(5.7/x)
-26(.09/y)
-No Discharge
.26(1320/x)
.26(.42/y)
.26(17. 7/x)
.26(21.8/x)
.53(5. 35/x)
.53(5. 7/x)
.53(.09/y)
of Pollutant
,53{1320/x)
.53(.42/y)
,53(17. 7/x)
.53(21, 8/x)
.37(5. 35/x)
.37(5. 7/x)
.37(.09/y)
l-c___________
.37(1320/x)
.37(.42/y)
.37(17. 7/x)
.37(21. 8/x)
.98(5. 35/x)
.98(5.7/x)
.98( .09/y)
,98(1320/x)
,98( ,42/y)
.98(17. 7/x)
.98(21.8/x)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
.16(89.5/z) .29(89.5/z) .26(89.5/z) .53(89.5/z) .37(89.5/z) .98(89.5/2) (2)
Sm3
are
(Ib per billion
in units of kg/1000
(1)
(2)
(3)
(4)
X =
Y =
Z =
All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Oust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two
process segments, the annual average limitations are in units of kg/62.3 million
SCF) of air scrubbed; in the case of the former process segment, the limitations
kkg (Ib per million Ib) of sand reclaimed.
Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
Within the range of 7.0 to 10,0 at all times.
Not regulated at NSPS for this segment.
Applicable to plants that cast primarily malleable iron where greater than 3,557 tons of metal are
poured per year and to plants that cast primarily ductile or gray iron.
normalized process wastewater flow (in gallons per 1,000 pounds
Actual
plant.
Actual
plant.
Actual
plant.
of metal poured) for the specific
1,000 SCF of air scrubbed) for the specific
normalized process wastewater flow (in gallons per
normalized process wastewater flow (in gallons per 1,000 pounds of sand reclaimed) for the specific
-------
NSPS
TABLE I 1-6 (Continued)
LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Subcategory and
TSS
30-Day * Daily
Max. Max.
30- Day
Max.
_
Da fly
Max.
fhenol_s(l)
30-Day "Daily
Max, Max.
Ferrous(5)
Casting Cleaning
Casting Quench
Oust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Hold Cool ing
15(5.35/x)
15(5.7/x)
15(.09/y)
15(1320/x)
15(.42/y)
15{17.7/x)
15(21.8/x)
38(5.35/x)
38(5.7/x)
38(.09/y)
38(1320/x)
38{.42/y)
38(17.7/x)
38(21.8/x)
10(5.35/x) 30(5.35/x) (3) (3)
10(5.7/x) 30(5.7/x) (3) (3)
10(.09/y) 30(.09/y) ,3(,09/y) .86(.09/y)
•No Discharge of Pollutants
10(1320/x) 30(1320/x) (3) (3)
10(.42/y)
10(17.7/x)
10(21.8/x)
30(.42/y)
30(17.7/x)
30(21.8/x)
•3(.42/y)
(3)
(3)
.86(.42/y)
(3)
(3)
15(89.5/zl 38(89.5/z) 10(89.5/z) 30(89.5/z) .3(89.5/z) .86(89.5/z)
15(5.35/x)
15(1.04/x)
15(.243/y)
15(47.3/x)
38(5.35/x)
38(1.04/x)
38(.243/y)
38(47.3/x)
10(5.35/x)
10(1.04/x)
10(.243/y)
10(47.3/x)
30(5.35/x)
30(1.04/x)
30(.243/y)
30(47.3/x)
(3)
.3(1.04/x}
,3(.243/y)
(3)
(3)
.86(1.04/x)
.86(.243/y)
(3)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two
process segments, the annual average limitations are in units of kg/62.3 million Sm3 (Ib per billion
SCF) of air scrubbed; in the case of the former process segment, the limitations are in units of kg/1000
kkg (Ib per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at NSPS for this process segment.
(5) Applicable to plants that cast primarily malleable iron where equal to or less than 3,557 tons of metal
are poured per year and to plants that cast primarily steel.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific
plant.
Y = Actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific
plant.
Z = Actual normalized process wastewater flow (in gallons per 1,000 pounds of sand reclaimed) for the specific
pi ant.
-------
NSPS
TABLE I 1-6 (Continued)
LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Subcategory and
P roces s ^Segment
Ferrous(5)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cool ing
Slag Quench
Het Sand
Reclamation
Zinc
Casting Quench
Die Castng
Melting Furnace
Scrubber
Mold Cooling
Copper
30-Day " Daily
Max. Max.
Lead
30-Day ' Daily
Max. Max.
Zinc
30-Day Daily
M
.16(5. 35/x)
.16(5. 7/x)
,16(.D9/y)
.16(1320/x)
.16(.42/y)
.16(17. 7/x)
.16(21. 8/x)
.16(89. 5/z)
.29(5. 35/x)
.29(5. 7/x)
.29{.D9/y)
,29(1320/x)
.29(.42/y)
,29(17. 7/x)
.29(21. 8/x)
.29(89. 5/z)
.39(5. 35/x)
.39(5. 7/x)
.39(.09/y)
Uf\ F"j4 t#*tijir*tfi^
-no u * scnarge
,39(1320/x)
-39(.42/y)
.39(17. 7/x)
.39(21. 8/x)
.39(89.5/z)
.79(5.35/x)
.79(5. 7/x)
.79( ,09/y)
.79(1320/x)
.79(.42/y)
.79(17. 7/x)
.79(21. 8/x)
.79(89. 5/z)
.56(5. 35/x)
.56(5. 7/x)
.56(.09/y)
ks -
.56(1320/x)
!56(17.7/x)
,56(21.8/x)
.56(89. 5/z)
1
1
1
1
1
1
1
1
.47(5.35/x)
.47(5. 7/x)
.47(.09/y)
.47(1320/x)
.47(.42/y)
.47(17. 7/x)
.47(21. 8/x)
.47(89.5/2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
.42(5.35/x) ,77(5.35/x) .26{5.35/x) .53(5.35/x) .29(5.35/x) .76(5.35/x) (2)
.42(1.04/x) .77(1.04/x) .26(1.04/x) .53(l.04/x) .29(1.04/x) .76(1.04/x) (2)
.42(.243/y) ,77(.243/y) .?6(.243/y) .53(.243/y) ,29(.243/y) .76(.243/y) (2)
.42(47.3/x) .77(47.3/x) .26(47.3/x) .53(47.3/x) .29(47.3/x) .76(47.3/x) (2)
All 30-Day Maxinum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of_the latter two
Sm3
are
(Ib per billion
in units of kg/1000
(1)
(2)
(3)
(5)
V ***
V =
z =
process segments, the annual average limitations are in units of kg/62.3 million
SCF) of air scrubbed; in the case of the former process segment, the limitations
kkg (lb per million Ib) of sand reclaimed.
Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
Within the range of 7.0 to 1D.O at all times.
Not regulated at NSPS for this process segment.
Applicable to plants that cast primarily malleable iron where equal to less than 3.557 tons of metal
are poured per year and to plants that cast primarily steel.
Actual normalized process wastewater flow (in gallons per 1,000 pounds
plant.
Actual
plant.
Actual
plant.
of metal poured) for the specific
DDO SCF of air scrubbed) for the specific
normalized process wastewater flow (in gallons per 1
normalized process wastewater flow (in gallons per 1,000 pounds of sand reclaimed) for the specific
-------
TABLE H-7
PSO LIMITATIONS* COVERING CONTINUOUS INDIRECT DISCHARGES
TTO 01] i Grease(1^ Phenol s_(2j Co *-ead Z1nc
Subcategory and
Process Segment
Aluminum
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Srinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
30- Day
Max.
(4)
.0095
.01
.2
5.91
2.6
.304
.0109
(4)
.54
8.29
1.77
,14
Daily
Max.
(4)
.029
.0308
.613
18.1
7.97
.935
.0335
(4)
1.65
25.4
5.41
.428
30-Day
Max.
(4)
.121
.0864
3.00
110
39.1
3.86
.399
(4)
7.18
110
23.5
5.09
Daily"
Max.
(4)
.363
.259
9.01
330
117
11.6
1.2
(4)
21.5
330
70.6
15.3
30- Day Daily
Max . Max .
(4) (4)
(4) (4)
.0026 .0074
.09 ,258
-No Discharge
(4) (4)
1.17 3.36
(4) (4)
(4) (4)
{4} (4)
.215 .617
-No Discharge
(4) (4)
.706 2.02
(4) (4)
30- Day
Max.
.0421
.0051
.0036
.126
of Pollut
4.63
1.64
.162
.0168
.506
.301
of Pollut
4.63
.988
.214
Dally
Max.
.0771
.0093
.0066
.231
8.48
3.01
.297
.0307
.128
.553
8.48
1.81
.392
30-Day
Max.
.039
.0047
.0034
.117
4.3
1.52
.111
.0104
.314
.187
2.86
.612
.132
Daily
Max.
.07il
.00§6
.0068
.237
8.7
3.09
.30S
.0211
.639
,38
5.84
1.25
.27
30-Day
Max.
.0431
.0052
.0037
.129
4.74
1.68
.166
.0116
.35
.208
3.19
.673
.148
Daily
Max.
.114
.0138
.0098
.343
12.6
4.45
.44
.0303
.916
.545
8.37
1.79
.387
pH
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
* All limitations are in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Met Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 million Sm^ (lb per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/1000 klcg ("tb per million Ib) of sand reclaimed.
(1) Alternate monitoring parameter for TTO.
(2) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(3) Within the range of 7.0 to 10.0 at all times.
(4) Not regulated at PSES for this process segment.
-------
TABLE II-7 (Continued)
PSES LIMITATIONS* COVERING CONTINUOUS INDIRECT DISCHARGES
Subcategory and
J^rpcess _Segjriefit^
Ferrous(5)
Casting Cleaning
Casti ng Quench
Oust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
SIag Quench
Wet Sand
Reclamation
UP QlLA^m^Cy. PJHIolsJ2.), c_°P£flll Mil Zinc
30-Day" O'aily ~ 30- Day Daily 30-Day "Daily 30-Day Daily 30-Oay Daily 30-Day O'aily
Hax. Max. Max. Max. Max. Max. Max. Max. Max. Max. Max. Max.
(4) (4) (4) (4) (4) (4) .0071
.00838 .0257 .476 1.43 (4) (4) .0076
.225 .646 .12
No Discharge of Pollutants
(4) (4) 1.76
.664
4.3
2.04
13.2
7.51
110
22.5
330
2.73 8.34
.026 .0797
.00838 .0257
.386 1.18
35
1,48
1.82
7.47
105
4.43
5.46
22.4
1.05
(4)
(4)
.224
3.01
(4)
(4)
.561
.0236
.0291
.0129
.0138
.218
nfr^--
3.19
1.02
.0428
.0527
.0116
.0124
.195
2.86
.911
.0384
.0473
.0237
.0252
.398
5.84
1.86
.0783
.0964
.0165
.0176
.278
4.07
1.30
.0546
.0673
.0437
.0466
.736
10.8
3.44
.145
.178
(3)
(3)
(3)
(3}
(3)
(3)
(3)
.642 .12
.217 .194 ,396 .276
.732
(3)
* All limitations are in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Het Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 million Sm3 (Tb per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/1000 kkg (lb per million Ib) of sand reclaimed.
(1) Alternate monitoring parameter for TTO.
(2) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(3) Within the range of 7.0 to 10.0 at all times,
(4) Not regulated at PSES for this process segment.
(5) Applicable to plants that are casting primarily ductile iron, to plants that are casting primarily malleable iron
where greater than 3557 tons of metal are poured per year, and to plants that are casting primarily gray iron where
greater than 1784 tons of metal are poured per year.
-------
Subcategory and
^Jl°£eJLs_%9m-eJ!J
Ferrous(6)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
Slag Quench
Wet Sand
Reclamation
TABLE II-7 (Continued)
PSES LIMITATIONS* COVERING CONTINUOUS INDIRECT DISCHARGES
TTO °_j_l.A Grease(1) ^£P°Is{2} Copper L.ead_ Zinc
30-Day 'Daily '30-Day Daily" 30-Day Daily 30-Day Daily 30-Day Daily 30-Day Daily
Hax. Max. Hax. Hax, Hax. Max. Max. Hax. Nax, Max. Max. Max.
(4)
.00838
.664
4.3
2.73
.026
.00838
(4)
.0257
2.04
13.2
8.34
.0797
.0257
(4)
.476
7.51
110
35
1.48
1.82
(4)
1.43
22.5
330
105
4.43
5.46
(4)
(4)
(4)
(4)
.0071
.0076
.225 .656 .12
No Discharge of Pollutants
(4) (4) 1.76
.386 1.18
Zinc
Casting Quench
Die Casting
Helting Furnace
Scrubber
Hold Cooling
.0304
.0064
1.29
.268
.093
.0196
3.95
.821
7.47
.446
.0864
20.3
3.94
22.4
1.34
.259
60.8
11.8
1.05
(4)
(4)
.224
(4)
.0026
.608
(4)
3.01
(4)
(4)
.642
(4)
.0074
1.74
(4)
.561
.0236
.0291
.12
.0187
,0036
.852
.166
.217 .291
.59 .418
.0344
.0066
1.56
.304
.0116
.0022
.527
.103
.0237
.0046
1.07
.209
.0129
.0025
.588
.114
1.1
.0339
.0066
1.54
.3
£"
.0129
,0138
,218
nf e .„
3.19
1.02
.0428
.0527
.0174
.0185
.293
4.3
1.37
.0576
.0709
.0353
.0376
.593
8.7
2.77
.117
.144
.025
.0266
.421
6.17
1,96
,0827
,102
,0656
.0699
1.1
16.2
5.15
.217
.267
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
* All limitations are in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Met Sand Reclamation,
Dust Collection Scrubber, and Helting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 million 5m3 {Ib per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/1000 kkg {Ib per million lb) of sand reclaimed.
(1) Alternate monitoring parameter for TTO.
(2) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(3) Within the range of 7.0 to 10.0 at all times.
(4) Not regulated at PSES for this process.
(6) Applicable to plants that are casting primarily steel, to plants that are casting primarily malleable iron where
equal to or less than 3557 tons of metal poured per year, and to plants that are casting primarily gray iron where
equal to or less than 1784 tons of metal are poured per year.
-------
TABLE I1-8
PSNS LIMITATIONS* COVERING CONTINUOUS INDIRECT DISCHARGES
Subcategory and
Process Segment
A1 umi mm
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Grindi nq Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Sc rubber
Mold Cooling
30-Day
Hax,
(4)
.0095
.01
.2
5.91
2,6
.304
.0109
(4)
.54
8.29
1.77
.14
Daily
Max.
(4)
.029
.0308
.613
18.1
7.97
.935
.0335
(4)
1.65
25.4
5.41
.428
30- Day
Max.
(4)
.121
.0864
3.00
110
39.1
3.86
.399
(4)
7.18
110
23.5
5.09
' Daily "
Max,
(<)
.363
.0259
9.01
330
11?
11.6
1.2
(4)
21.5
330
70, i
IS. 3
30-Day Dally
Max. Max.
(4) (4)
(4) (4)
.0026 .0074
.09 .258
-No Discharge
(4) (4)
1.17 3.36
(4) (4)
(4) (4)
(4) (4)
.215 .617
-No Discharge
(4) (4)
.706 2.02
(4) (4)
30-Day Daily
Max. Max.
.0421
.0051
.0036
.126
of Poll
4.63
1.64
.162
.0168
.506
.301
of Poll
4.63
.988
.214
.0771
.0093
.0066
.231
8.48
3.01
.297
.0307
.928
.553
8.48
1.81
.392
30-Day
Max.
.039
.0047
.0034
.117
4.3
1.52
.151
.0104
.314
.187
2.86
.612
.132
Daily 30-Day
Max . Max .
.0791 .0431
.0096 .0052
.0068 .0037
.237 .129
8.7 4.74
3.09 1.68
.305 .166
.0211 .0116
.639 .35
.38 .208
5.84 3,19
1.25 .673
.27 .148
Daily
Max.
.114
.0138
.0098
.343
12.6
4.45
.44
.0303
,916
.545
8.37
1.79
.387
pH
<3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
* All limitations are in units of kg/1000 kkg (Ib per rail lion Ib) of metal poured except for the Wet Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 million Sm^ (Ib per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/1000 kkg (Ib per million Ib) of sand reclaimed.
(1) Alternate monitoring parameter for TTO.
{2} Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(3) Within the range of 7,0 to 10.0 at all times.
(4) Not regulated at PSNS for this process segment.
-------
Subcategory and
Proc e s s__Se5m£,nt.
Ferrous(5)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melti ng Furnace
Scrubber
Hold Cooling
Slag Quench
Wet Sand
Reclamation
TABLE II-8 (Continued)
PSNS LIMITATIONS* COVERING CONTINUOUS INDIRECT DISCHARGES
11° Oil A. Grease(l) Phenols{2) Copper Lead Zinc
30-Day D'aily ' 30-Day Daily" 30-Day "Daffy 30-Day Dally 30-Day Dally 30-Day Dally
Max. Max. Hax. Max, Max. Max, Max. Max, Max, Max. Max. Max.
(4)
.00838
.664
4.3
2.73
.026
.00838
(4)
.0257
2.04
13.2
8.34
.0797
.0257
(4)
.476
7.51
110
35
1.48
1.82
(4)
1.43
22.5
330
105
4.43
5.46
(4)
(4)
.225
Nn ni<;
(4)
1.05
(4)
(4)
(4} .0071
(4) .0076
.646 .12
charge of Poll
(4) 1.76
3.01 .561
(4) .0236
(4) .0291
.0129
.0138
.218
3.19
1.02
.0428
.0527
.0116
.0124
.195
2.86
.911
.0384
.0473
.0237
.0252
.398
5.84
1.86
.0783
.0964
.0165
.0176
,278
4.07
1.30
.0546
.0673
,0437
.0466
.736
10,8
3.44
.145
.178
(3)
(3)
(3)
(3)
(3)
(3)
(3)
.386
1.18
7.4?
22.4
.224
.642
.12
.217 .194
.396 .276
.732
(3)
UJ *
00
{1}
(2)
(3)
(4)
(5)
All limitations are in units of kg/1000 kkg (lh per million Ib) of metal poured except for the Wet Sand Reclamation*
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62,3 million Sm-* {Ib per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/1000 kkg {Ib per million Ib) of sand reclaimed.
Alternate monitoring parameter for TTO.
Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
Within the range of 7.0 to 10.0 at all times.
Not regulated at PSNS for this process segment.
Applicable to plants that are casting primarily ductile iron, to plants that are casting primarily malleable iron
where greater than 3557 tons of metal are poured per year, and to plants that are casting primarily gray iron where
greater than 1784 tons of metal are poured per year.
-------
TABLE I1-8 (Continued)
PSNS LIMITATIONS* COVERING CONTINUOUS INDIRECT
Oil & Grease(Ij: PhenqJ_sJ[2)_ Qoj3g_er Lead Zinc
' ~
Subcategory and
Process Segment
Ferrous (6)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrybber
Investment Casting
Helting Furnace
Scruhber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
Zinc
Casting Quench
Die Casting
Helting Furnace
Scruhher
Mold Cooling
30-Day
Max.
(4)
.00838
.664
4.3
2.73
.026
.00838
.386
.0304
.0064
1.29
.268
Daily
Max.
(4)
.0257
2.04
13.2
8.34
.0797
.0257
1.18
.093
.0196
3.95
.821
30- Day
Max.
(4)
.476
7.51
110
35
1.48
1.82
7.47
.446
.0864
20.3
3.94
Daily
Max.
(4)
1.43
22.5
330
105
4.43
5.46
22.4
1.34
.259
60,8
11.8
30-Day
Max.
(4)
(4)
.225
Daily
Max.
(4)
(4)
.656
30-Day
Hax.
.0071
.0076
.12
—No Discharge of Pollut
(4)
1.05
(4)
(4)
.224
(4)
.0026
.608
(4)
(4)
3.01
(4)
(4)
.642
(4)
.0074
1.74
(4)
1.76
.561
.0236
,0291
.12
.0187
.0036
.852
.166
Daily
Max.
.0129
.0138
.218
3.19
1.02
.0428
.052?
.217
,0344
.0066
1.56
.304
30-Day
Max.
.0174
.0185
.293
4.3
1.37
.0576
.0709
.291
.0116
.0022
.527
.103
Daily 30-Day
Hax. Max.
,0353 .025
.0376 .0266
.513 .421
8.7 6.17
2.77 1.96
.117 .0827
.144 .102
.59 .418
.0237 .0129
.0046 .0025
1.07 .588
.209 .114
Daily
Hax.
.0656
.0699
1.1
16.2
5.15
.217
.267
1.1
.0339
.0066
1.54
.3
pH
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
* All limitations are in units of kg/1000 kkg (lb per million Ib) of metal poured except for the Wet Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 million Sm3 (lb per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/lQQD kkg (Ib per mill ion lb) of sand reclaimed.
(1) Alternate monitoring parameter for TTO.
(2) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(3) Wtbin the range of 7.0 to 10.0 at all tines.
(4) Not regulated at PSNS for this process segment.
(6) Applicable to plants that are casting primarily steel, to plants that are casting primarily malleable iron where
equal to or less than 3557 tons of metal or poured per year, and to plants that are casting primarily gray iron
where equal to or less than 1784 tons of metal are poured per year.
-------
-------
SECTION III
INTRODUCTION
LEGAL AUTHORITY
Effluent limitations guidelines and standards are being
promulgated for the metal molding and casting point source
category under authority of Sections 301f 304, 306, 307, and 501
of the Federal Water Pollution Control Act, as amended {the Clean
Water Act or the Act). The following paragraphs describe the
Clean Water Act and subsequent Settlement Agreement that provide
the legal basis for this rulemaking.
Background - The Clean Water Act
The Federal Water Pollution Control Act Amendments of 1972
established a comprehensive program to "restore and maintain the
chemical, physical, and biological integrity of the Nation's
waters." By July 1, 1977, existing industrial dischargers were
required to achieve effluent limitations requiring the
application of the best practicable control technology currently
available (BPT), Section 301 (b)(l)(A); and by July 1, 1984,
these dischargers were required to achieve effluent limitations
requiring the application of the best available technology
economically achievable (BAT), Section 301 (b){2)(A). According
to the Act, BAT should result in reasonable further progress
toward the national goal of eliminating the discharge of all
pollutants. New industrial direct dischargers were required to
comply with Section 306 new source performance standards (NSPS),
based on the best available demonstrated technology; and new and
existing sources that introduce pollutants into publicly owned
treatment works {POTWs} were subject to pretreatment standards
under Sections 307 (b) and (c) of the Act. Direct dischargers
are those plants that discharge pollutants into navigable waters
of the United States. Plants that introduce pollutants into
POTWs are called indirect dischargers. The requirements for
direct dischargers were to be incorporated into National
Pollutant Discharge Elimination System (NPDES) permits issued
under Section 402 of the Act; however, pretreatment standards
were made enforceable directly against any owner or operator of a
facility that is an indirect discharger.
Although Section 402 (a)(l) of the 1972 Act authorized the
setting of requirements for direct dischargers on a case-by-case
basis, Congress intended that, for the most part, control
requirements would be based on national regulations promulgated
by the Administrator of EPA. To this end, Section 304 (b) of the
Act required the Administrator to promulgate regulations
providing guidelines for effluent limitations setting forth the
degree of effluent reduction attainable through the application
of BPT and BAT. Moreover, Section 306 of the Act required
41
-------
promulgation of regulations for NSPS, and Sections 304 (f), 307
(b), and 307 (c) required promulgation of regulations for
pretreatment standards. In addition to these regulations for
designated industrial categories, Section 307 (a) of the Act
required the Administrator to promulgate effluent standards
applicable to all dischargers of toxic pollutants. Finally,
Section 501 (a) of the Act authorized the Administrator to
prescribe any additional regulations necessary to carry out his
functions under the Act.
The EPA was unable to promulgate many of these regulations by the
dates contained in the Act, As a result, EPA was sued in 1976 by
several environmental groups. In settlement of this lawsuit, EPA
and the plaintiffs executed a Settlement Agreement, which was
approved by the Court. This Agreement required EPA to develop a
program and adhere to a schedule for promulgating, for 21 major
industries, BAT effluent limitations, pretreatment standards, and
new source performance standards for 65 toxic pollutants and
classes of pollutants. (See Natural Resources Defense Council,
Inc. v. Train, 8 ERC 2120 (D.D.C. 1976), modified, 12 ERC 1833
(D.D.C. 1979), modified by Orders dated October 26, 1982, August
2, 1983, January 6, 1984, July 5, 1984, and January 7, 1985)
The Clean Water Act amendments of 1977 incorporated several of
the basic elements of the Settlement Agreement program for
priority pollutant control. Sections 301 (b)(2)(A) and 301
(b)(2)(C) of the Act now require the achievement by July 1, 1984,
of effluent limitations requiring application of BAT for toxic
pollutants, including the 65 toxic pollutants and classes of
pollutants which Congress declared toxic under Section 307 (a) of
the Act. The 1977 Amendments to the Clean Water Act added
Section 301(b)(2)(EJ, establishing "best conventional pollutant
control technology" (BCT) for the discharge of conventional
pollutants from existing industrial point sources. Section
304(a)(4) designated the following as conventional pollutants:
BOD, TSS, fecal coliform, pH, and any additional pollutants
defined by the Administrator as conventional. The Administrator
designated oil and grease a conventional pollutant on July 30,
1979 (44 FR 44501). Likewise, EPA's programs for new source
performance standards and pretreatment standards are now aimed
principally at toxic pollutant control. Moreover, to strengthen
the toxic pollutant control program, Congress added Section 304
(e) to the Act, authorizing the Administrator to prescribe best
management practices (BMPs) to prevent the release of toxic and
hazardous pollutants from plant site runoff, spillage or leaks,
sludge or waste disposal, and drainage from raw material storage
associated with, or ancillary to, the manufacturing or treatment
process.
Background - Prior Regulations
There are no prior promulgated regulations applicable to this
point source category. On November 15, 1982, EPA proposed
regulations to limit the discharge of process wastewater
pollutants from metal molding and casting plants to waters of the
42
-------
United States and into publicly owned treatment works (PQTWs).
(See 47 FR 51512.) After proposal, the Agency conducted an
extensive program to verify its data base, and sampled wastewater
treatment systems employed at metal molding and casting plants.
A notice of availability was published on March 20, 1984 {49 PR
10280), to make available for public review additional data and
information gathered after proposal. The notice also summarized
preliminary analyses of the supplemented data base and EPA's
assessment of how these data and analyses would influence the
final regulations. However, some of the data and analyses were
not completed in time for the March 20 notice. A second notice
of availability was published on February 15, 1985 (50 FR 6572)
in order to make available for public comment these additional
data and the results of certain technical and economic analyses.
SUMMARY OF METHODOLOGY
The Agency has gathered background information and supporting
data for this regulation since 1974. A substantial portion of
the data gathering and analysis efforts occurred before the
regulation was proposed. Additional data were obtained after
proposal and analyses were performed using these data. These
additional data and the results of the analyses were made
available for public comment.
The initial methodology and data gathering efforts used in
developing the proposed metal molding and casting regulation were
summarized in the preamble to the proposed regulation (47 FR
51512; November 15, 1982) and were described in detail in the
Proposed Development Document for Effluent Limitations Guidelines
and Standards for the Metal MoldTng and Casting fFounjrLesJ Pol rTt
Source Category, EPA, 440/l-82-070b, November, 1982).
In summary, before proposal, EPA studied the metal molding and
casting category to determine whether differences in the raw
materials, final products, manufacturing processes, equipment,
age and size of plants, water use, wastewater characteristics, or
other factors required the development of separate effluent
limitations guidelines and standards for different segments (or
subcategories) of the category. This study included the
identification of raw waste characteristics, sources and volumes
of water used, processes employed, and sources of wastewater.
Sampling and analysis of specific wastewaters enabled EPA to
determine the presence and concentration of pollutants in
wastewater discharges.
EPA also identified wastewater control and treatment technologies
for the metal molding and casting category. The Agency analyzed
data on the performance, operational constraints, and reliability
of these technologies. In addition, EPA considered the impacts
of these technologies on air quality, solid waste generation,
water scarcity, and energy requirements.
43
-------
The Agency estimated the costs of each control and treatment
technology considered using cost equations baaed on standard
engineering analyses. EPA derived control technology costs for
model plants representative of the metal molding and casting
plants in the Agency's data base. The Agency then evaluated the
potential economic impacts of these costs on the category,
The Agency also developed a financial profile for model plants
representative of the plants in EPA's data base using production
data from Data Collection Portfolios (DCPs) and financial data
from publicly available sources. Using financial information and
compliance cost estimates, the impacts of the proposed
regulations on plants with a discharge were determined. Those
impacts were extrapolated to the estimated total number of plants
in the metal molding and casting category that discharge
wastewaters directly or indirectly to navigable waters.
Following publication of the proposed regulations on November 15,
1982 (see 47 Fa 51512), the Agency received numerous comments. A
number of significant issues were raised by the commenters; these
included the feasibility of complete recycle, the validity of the
data base supporting complete recycle, the treatment
effectiveness data base, the magnitude of the discharges from die
casting operations, the accuracy of EPA's estimates of compliance
costs, and the projected economic impacts of the proposed
regulations. Comments relating to these issues prompted the
Agency to verify its technical data base and to reconsider many
aspects of the proposed regulations.
After a review of the data base, the Agency corrected, as
appropriate, the errors noted in the comments relating to
previously-reported data. As part of these efforts, the Agency
made a number of comment verification requests to plants that
submitted comments on the proposed regulations or were cited
specifically in comments submitted by others. These comment
verification activities are discussed in the Agency's first
notice of availability and request for comments published in the
Federal Register on March 20, 1984 at 49 FR 10280. Also
discussed in the March 20, 1984 notice are the results of the
Agency's analyses of the supplemented data base and any
appropriate modifications to or confirmations of the underlying
facets of the proposed regulations. The Agency also solicited
comments and information concerning a number of other aspects of
the rulemaking.
On February 15, 1985, the Agency published, at 50 FR 6572,
another notice of availability and request for comments
concerning additional data that were gathered and analyses that
were completed after March 20, 1984. In the February 15 notice,
the Agency summarized the major issues raised in comments on its
March 20, 1984 notice and requested additional specific
information.
44
-------
The Agency has reviewed all information received since its
November 15, 1982 proposal and the publication of the two notices
of availability just described. EPA used the new data and
information to analyze and respond to public comments. To the
extent that new information confirmed arguments made by
commenters, EPA revised its regulatory options and performed
additional analyses to evaluate the revised options. These
additional analyses and the regulatory options considered by EPA
as the bases for the final regulations are discussed in more
detail in later sections of this document.
Upon consideration of all available information, EPA identified
various control and treatment technologies as BPT, SAT, NSFS,
PSES, and PSNS. The final regulations, however, do not require
the installation of any particular technology. Rather, they
require achievement of effluent limitations and standards
representative of the proper application of these technologies or
equivalent technologies. A plant's existing controls should be
fully evaluated, and existing treatment systems fully optimized,
before commitment to any new or additional in-plant or end-of-
pipe treatment technology.
DATA GATHERING EFFORTS
This section describes in more detail EPA's efforts to collect
and evaluate technical data during the development of regulations
for the metal molding and casting point source category. The
section is organized chronologically.
Pre-Proposal
Review of Existing Data
Initially, all existing information on the metal molding and
casting industry was collected from previous EPA foundry studies,
literature sources, trade journals, inquiries to EPA regional and
state environmental authorities, and from raw material and
equipment manufacturers and suppliers. These sources provided
information on industry practices and wastewater generation, and
gave direc-tion to the effort of collecting additional data.
Previous Studies. Previous Federal government contracted studies
o?the foundry category were examined. These studies were
prepared by Cyrus Wm. Rice Division of NUS Corporation under
Contract No. 68-01-1507 and A.T. Kearney and Company, Inc. for
the National Technical Information Service, U.S. Department of
Commerce, PB-207 148. These studies provided data on the types
of metals cast, plant size, geographic distribution,
manufacturing processes, waste treatment technology, and raw and
treated process wastewater characteristics at specific plants.
Literature Survey. Published literature in the form of
handbooks, engineering and technical texts, reports, trade
journals, technical papers, periodicals, and promotional
materials were examined. Those sources used to provide
45
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information for this study are listed in Section XIV, In
addition, the "Metal Casting Industry Directory" {a Penton
Publication) provided information on the number, size, and
distribution of foundry operations, as well as plant
characteristics.
Regional and State Data. EPA Regional offices and State
environmental agencies were contacted to obtain permit and
monitoring data on specific plants. The EPA's Water Enforcement
Division's "Permits Compliance System" was used as another
mechanism to identify and gather additional information on metal
molding and casting plants.
Raw Material Manufacturers and Suppliers. Manufacturers and
suppliers of foundry raw materials and process chemicals, such as
core binders and mold release agents, were contacted for
information about the chemical compositions of their products.
Since many of these materials are considered proprietary by the
vendor, only generic information was obtained about these
products. From this information, predictions were made as to the
possible introduction of toxic pollutants into metal molding and
casting process wastewaters due to the presence of these
materials in the facility work area.
Equipment Ma n u £ a ctu. rers and Suppliers. Manufacturers and
suppliers of foundry process and pollution control equipment were
contacted to obtain engineering specifications and technical
information on metal molding and casting manufacturing processes
and air and water pollution control practices.
Sampling Data - The 1974 Sampling Effort. In 1974, the Agency
visited and collected wastewater samples at 19 ferrous foundries
as part of the rulemaking effort for the iron and steel point
source category. Analyses were performed on these samples to
determine concentrations of conventional pollutants, 4AAP
phenolics, cyanide, ammonia, and some metals. These existing
data were also reviewed in the early stages of this rulemaking
effort.
A preliminary review of the data that existed at the start of
this study indicated the need for more extensive plant data. The
needed data were collected through the use of the industry survey
and sampling program, described below.
Data Collection Portfolio
A questionnaire, or data collection portfolio (DCP), was designed
to collect information about all types of plants engaged in metal
molding and casting. Information was solicited about plant size,
age, historical production, number of employees, type of metal
cast, manufacturing processes, water usage, raw material and
process chemical usage, wastewater generation, wastewater
treatment, characteristics of the plant's raw and treated
wastewater, land availability, and other pertinent factors.
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The Penton "Metal Casting Industry Directory", which identifies
4,400 metal molding and casting operations, was used as the
primary basis for the selection of plants to be included in the
survey. The actual plant selection is described in greater
detail in the Administrative record for this rulemaking. After
reviewing existing treatment processes, in-process control
trends, information available in the Penton casting industry
directory, and other data, a total of 1,269 plants were surveyed
using the DCP questionnaire (approximately 29 percent of the
total plant population identified in the Penton census in 1977).
Penton Census information used in the selection of plants to be
surveyed is summarized in Table III-l.
In addition to the distribution of plant surveys described above,
metal molding and casting DCPs were mailed to 226 plants engaged
in the casting of lead. These plants proved to be primarily
involved in the manufacturing of lead batteries and have been
assigned to the battery manufacturing point source category.
General summary tables included in the Administrative record for
this rulemaking provide summaries of the plant survey data.
Sampling and Analytical Program - 1977 to 1979
In 1978, EPA performed a more thorough sampling and analysis
program. Unlike the 1974 effort described under "Review of
Existing Data", which was conducted as part of the rulemaking
effort for the iron and steel category, this later effort was
conducted specifically to collect information and data for use in
the development of effluent limitations and standards for the
metal molding and casting point source category. The following
distribution of facilities was sampled: three aluminum casting
plants, four copper casting plants, eight iron and steel casting
plants, one lead casting plant, one magnesium casting plant, and
one zinc casting plant. In addition, three plants that cast both
aluminum and -zinc were sampled. During the 1978 sampling and
analysis effort, EPA analyzed representative wastewaters from
these plants for the presence and quantities of the toxic
pollutants listed in Section 307(a) of the Clean Water Act, as
well as for several conventional and nonconventional pollutants.
The plants chosen for sampling were selected to provide a
representative cross-section of the manufacturing processes,
types of metal cast, and wastewater treatment present in the
category. Before visiting a plant, EPA reviewed available
information on manufacturing processes and wastewater treatment
at that plant. The Agency then selected sample points from which
process wastewaters and treated effluent would be collected for
analysis. Prior to each sampling visit, the Agency prepared,
reviewed, and approved a detailed sampling plan showing the
selected sample points and the overall sampling procedures.
In general, samples were taken on three consecutive days of plant
operation. Haw wastewater and treated effluent samples were
collected, as well as samples of the plant intake water.
Wherever possible, samples were collected by an automatic, time-
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series compositor over three consecutive operational periods (8
to 24 hours per period at most plants). When automatic
compositing was not possible, grab samples were taken and
composited manually.
Full details of the sampling and analysis program and the data
derived from that program are presented in Section V of this
document.
All of the data obtained from both the 1974 and the later
sampling effort were analyzed to determine process wastewater
characteristics and mass discharge rates for each sampled plant.
Proposal and Solicitation of Comments
The DCP survey responses, along with additional data, were used
as the basis of the November 15, 1982 proposed regulation. The
purpose of that action was the proposal of effluent limitations
guidelines and standards controlling wastewater discharges to
waters of the United States and into POTWs from metal molding and
casting (foundry) facilities (47 FR 51512).
Additional comments and information on six specific issues were
solicited as part of the notice of proposed rulemaking (see
Section XXIV; 47 FR 51529 and 51530). Comments and data were
sought on: 1) small plant production, employment, sales,
revenues, and capitalization and on the financial profiles for
all plants developed in the economic methodology; 2) the ability
to operate processes properly at complete recycle/no discharge
(100 percent recycle); 3) long-term raw and treated effluent
analytical data for plants with well-operated lime and settle
treatment systems with 90 percent recycle of treated process
wastewater from casting processes with proposed limitations and
standards of no discharge of process wastewater pollutants; 4)
the Agency's comparisons between 100 percent recycle and the two
discharge alternatives of 90 percent and 50 percent recycle for
15 process segments; 5) the feasibility of substituting non-toxic
process chemicals for process chemicals which may contain toxic
organic pollutants; and 6) economic information, not only on
plant closures and job losses, but also on modernization or
expansion plans, ability to pass price increases through to
customers, plant profitability, the need for additional employees
to operate and maintain pollution control equipment,
international competitiveness, the availability of less costly
control technology, and information that would be helpful in
developing the definition of a "small" plant.
Comments Received in Response to the Proposed Regulation
The Agency received numerous comments on the proposed regulation.
These comments criticized data and analyses that were fundamental
to the regulation and prompted the Agency to verify its data base
and to reconsider many aspects of the regulation. Interested
persons are urged to review the rulemaking record for a complete
understanding of the many issues raised in comments. Discussed
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below are those issues that appeared to be of greatest concern to
commenters and that warranted further study by the Agency.
Feasibility of Complete Recycle. The most prevalent comment
received by EPA in response to the proposed regulation was that
the proposed requirement for complete recycle with no allowance
for wastewater discharge was not feasible technically. It was
asserted that recycle systems must have discharge ("blowdown") to
remove dissolved solids and other pollutants which would
otherwise build up in these systems, causing scaling and
corrosion. Commenters asserted that sophisticated technology
(e.g., reverse osmosis, ion exchange, etc.) was necessary to
achieve complete recycle and that these technologies were not
demonstrated in the industry. Further, it was asserted that the
feasibility of recycle systems to achieve complete recycle is
dependent upon the dissolved solids content of the intake water
supply available to individual plants to make-up for water losses
such as evaporation and moisture removed in sludges.
Data Base Supporting Complete Recycle. Trade associations and
some members of industry asserted that numerous individual plants
indicated by EPA to demonstrate complete recycle with no
discharge were misrepresented in the data base. These commenters
asserted that most of the plants in EPA's data base which employ
wastewater recycle systems have periodic discharges to allow
equipment maintenance and repair, regular removal of "wet"
sludges, "discharges" to groundwater, discharges that are removed
for off-site disposal by contract haulers, and discharges to
adjacent industrial treatment facilities. As such, coramenters
claimed that these plants do not demonstrate the proposed
requirement for complete recycle with no discharge.
Treatment Effectiveness Data Base. A number of comments on the
proposed regulation indicated that the Agency did not use an
appropriate basis for establishing effluent limitations for those
process segments where discharges were allowed. It was asserted
that the Agency's use of the Combined Metals Data Base (the data
base from well operated lime and settle treatment systems, used
in other industries, that was used to establish lime and settle
treatment effectiveness for the metal molding and casting
industry at proposal) was not appropriate because these data
represent treatment of wastewaters from industries whose
wastewaters are not comparable to wastewaters from the metal
molding and casting industry.
Mass-Based Effluent Limitations and Standards. Some commenters
indicated that effluent limitations and standards for the metal
molding and casting industry should be based on allowable
concentration-based limitations, rather than mass-based
limitations. Further, it was asserted that there was no valid
statistical relationship between tne mass of pollutants
discharged and the mass of metal poured (or any other production
normalizing parameter).
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Die Casting. EPA received many comments which asserted that die
casting operations discharge very small quantities of wastewaters
and, therefore? that die casters should not be regulated,
Compliance Costs. Many commenters asserted that EPA's estimates
of the cost to comply with the proposed regulations were
understated substantially. These commenters asserted that the
true cost of complying with the proposed regulations was
substantially in excess of $100 million per year.
Economic Impact. Many commenters indicated that the Agency's
economic analysis vastly understated the impact of the proposed
regulations because it did not consider the major downturn in the
economy since 1979, the consequent reduction in demand for cast
products, and the general state of the industry (profits, reduced
employment/ and significant plant closures). Also, it was
asserted that EPA did not consider the impact of foreign imports
in the analysis. In a similar vein, it was asserted that EPA did
not adequately consider the impact of the proposed regulation on
small plants. It was suggested that all small plants, as defined
by the Small Business Administration (SBA), should be exempted
from complying with the regulations.
Data Gathering Efforts in Response to Comments Received on the
Proposal
After proposal, the EPA conducted an extensive program to respond
to comments received. This often included gathering additional
data in order to supplement the preproposal data base or to
verify comments received on the proposal. These data gathering
efforts are described below,
Numerous comments and public hearing statements raised issues
pertaining to the feasibility of complete recycle and the die
casting segments of the metal molding and casting category. In
response to these comments, the Agency contacted all plants
considered to have systems with complete recycle and all die
casting plants that submitted comments and requested that they
support their assertion that they should be excluded from
regulation because their discharges are environmentally
inconsequential. Numerous requests also were made to die casting
plants and to other metal molding and casting plants to obtain
(1) long term data on the performance of wastewater treatment
systems, (2) cost data on existing treatment systems and
technology believed necessary to comply with the proposed
regulation, (3) information and data on the technical feasibility
of complete recycle/no discharge systems, (4) confirmation of
discharge status and previous submissions (DCP's and telephone
surveys) by all plants included in EPA data base as having
complete recycle with no discharge {except those plants known to
have closed)/ and (5) metal molding and casting process data,
including flow data, where none was previously available to
provide a basis for interpreting other data submissions, and
related information. The formats and a number of the specific
inquiries used in these requests were developed, in part, with
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the cooperation of the American Foundrymen's Society (APS) and
the American Die Casting Institute (ADCI).
The data and information received as a result of this
solicitation were used to characterize the wastewaters from die
casting operations and estimate their volume, as well as to
supplement the Agency's body of information on recycle and
treatment systems as applied to die casting plants.
In addition, 13 plant visits were made by the Agency in order to
observe die casting operations and in-place treatment
technologies. One of these visits led to a three day sampling
visit which allowed the Agency to collect additional analytical
data on die casting wastewaters. This visit supplemented data
gathered by sampling visits at five other die casting facilities
prior to proposal of the regulations.
in response to comments received on the data base supporting the
feasibility of complete recycle, EPA requested all plants with
processes identified as having complete recycle with no discharge
to verify the status of recycle and discharge, except where
plants were known to be closed and could not be contacted. In
many instances this request was accompanied by copies of the
previously completed DCPs and telephone surveys (as appropriate)
which had led to no discharge findings for each of these plants,
and an explanation of what was considered "complete recycle" for
purposes of these regulations.
The results of this survey were used to supplement the EPA's
water use data base/ especially the number of plants achieving no
discharge. Recycle rate data were included along with data
previously in the record from DCPs and plant visits and used to
ascertain the recycle rates which served as a basis for final
limitations.
The Agency also performed a model analysis of recycle systems to
supplement and confirm industry data on demonstrated rates of
recycle and blowdown, if any. The recycle model analysis
methodology and results are discussed in detail in Section VII of
this document.
In response to comments on the treatment effectiveness data base,
the Agency collected a significant amount of data provided to EPA
or State agencies in discharge monitoring reports (DMRs). DMR
data include long-term treated effluent quantities or
concentrations of pollutants discharged from active foundries.
The DMRs are a requirement of the National Pollutant Discharge
Elimination System and are submitted by individual plants to
inform State and Regional personnel of the plant's status
relative to compliance with its discharge permit.
DMR data were obtained from 75 foundries during the metal molding
and casting rulemaking effort. Although some of the data were
submitted to EPA by individual plants, the bulk of the data were
collected by the following method: First, states that had a large
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number of foundries were identified for efficiency in data
collection. Seven states and EPA Region 3 were chosen for data
collection trips. The seven states include Alabama, Connecticut,
Illinois, Michigan, New York, Ohio, and Wisconsin; Region 3
includes Delaware, the District of Columbia, Maryland,
Pennsylvania, Virginia, and West Virginia. The EPA offices of
these states and the Region 3 office in Philadelphia were then
visited by EPA's contractor for purposes of data collection.
At the EPA offices, a review of all available NPDES files from
1980 through 1983 was conducted in order to ensure that all data
incorporated into EPA's data base were representative of well-
operated treatment systems. A list of the specific criteria used
and details of the selection process can be found in the record
for this rulemaking. After a thorough review of the data, long-
term data from the discharge monitoring reports of 34 plants
remained. These data were included in the EPA's long-term data
base; certain of these data were used to develop treatability
levels that form the basis of the final regulations.
Finally, a third round of plant site and sampling visits was
undertaken in 1983, Thirty-three plants were visited, and seven
plants were sampled. Thirteen of these site visits and one of
the sampling visits were conducted at die casting plants, as
described above. Site or sampling visits were conducted for
several reasons: 1) to observe operations and treatment at die
casting plants; 2) to observe operations and treatment and to
collect data from small die casters and other small shops; 3) to
verify the discharge status of plants reported to have no
discharge, especially for air scrubbing operations; 4) to observe
high rate or complete recycle operations; 5) to collect data on
chemical addition and sedimentation treatment technology or on
chemical addition, sedimentation, and filtration technology; and
6) to collect water chemistry data for use in determining the
effects of water chemistry on a plant's ability to achieve high
recycle rates, A more detailed description of the sampling and
analysis program and the data derived from that program can be
found in Section V of this document.
March 1984 Notice of Availability of and Request for Comments
As a result of data gathering and verification following
proposal, the Agency acquired a large amount of additional
information on which to base this rulemaking. On March 20, 1984,
the Agency published a Notice of Availability and Request for
Comments {49 PR 10280). In addition to requesting further
information on several of the proposal issues cited above, the
Agency solicited comments on the following: 1) verification of
the discharge status of plants in the Agency's data base
(especially those plants thought to be zero dischargers); 2) the
achievability of the recycle rates being considered by the Agency
if regulations were not based on complete recycle; 3) the
preliminary recycle model analysis performed by the Agency? 4)
the influence of multiple process operations on a plant's ability
to achieve a high rate of recycle; and 5) characteristics of
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wastewaters from die casting plants.
Comments Received in Response to the March 1984 Notice
The Agency received a number of comments on the March 20, 1984
notice of availability. Many of these comments reiterated
concerns expressed regarding the proposed regulation. Listed
below are those issues which appeared to be of greatest concern
to commenters.
Recycle Model Analysis. Trade associations and some members of
industry asserted that the Agency recycle model did not consider
central treatment of combined foundry process wastewaters and
whether central treatment would affect a plant's ability to
achieve high rate or complete recycle.
Environmental Assessment. The Small Business Administration and
trade associations requested that the Agency make available an
environmental assessment of metal molding and casting discharges.
These commenters stated that an environmental assessment would
confirm their assertion that many sources of process wastewaters
being considered by EPA should be excluded from regulation
pursuant to Paragraph 8 of the EPA-NRDC Consent Decree because of
the small quantities of pollutants discharged, especially by
small plants,
Treajtmejvt Effectiveness Data Base. A number of commenters stated
that treatment system performance data from plants in the metal
molding and casting industry should be used as the basis for
determining treatment effectiveness concentrations, rather than
the Combined Metals Data Base.
Production Normalizing Parameters. A number of comments made on
the proposed regulations were reiterated. These comments
objected to the Agency's use of tons of metal poured and tons of
sand used as production normalizing parameters for relating
process wastewater flow and pollutant loads for wet scrubbers.
The production normalizing parameters are used in developing
mass-based limitations. The commenters again stated that the air
flow through these wet scrubbers (in units of 1000 standard cubic
feet [scfm}) should be used as the production normalizing
parameter.
Economic Analysis. EPA received comments on the March 20, 1984
notice, as it had on the proposal, that in view of the likelihood
of severe economic impact on small plants, EPA must undertake a
Regulatory Flexibility Analysis.
Data Gathering Efforts in Response to Comments Received on the
March 1984 Notice.
Much of the work conducted after March 1984 was a continuation of
efforts that had begun in response to comments on the proposed
regulation. Additional work was completed on the recycle model,
including analyses of the effect of make-up water quality, sludge
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moisture content, and central treatment on achievable recycle
rates.
In response to comments concerning production normalizing
parameters, a correlation anlaysis was completed for wet
scrubbers comparing water use to tons of metal poured, tons of
sand used, and air flow through the scrubber. The results of
this analysis prompted the Agency to establish air flow, in 1000
scf, as the normalizing parameter for all scrubber-based process
segments. Details of this analysis and complete results may be
found in the record for this rulemaking.
The Agency also continued its efforts to develop treatment
effectiveness concentrations based on plants in the metal molding
and casting category. Additional DMR data were obtained, and
added to the Agency's data base. Several alternative sets of
treatment effectiveness concentrations were developed; Section
VII describes these efforts in detail.
February 1985 Notice of_ Availab i 1 ity and Request £p_r Comments
On February 15, 1985, a second Notice of Availability and Request
for Comments, (50 FR 6572) was published to make available to the
public the Agency's analysis of the additional data gathered and
analyses performed since publication of the March 1984 Notice,
Comments were solicited on several additional issues in the
second notice: 1) the high concentrations of lead and zinc
detected in treated effluents from metal molding and casting
plants employing lime and settle treatment; 2) the feasibility of
substituting dry scrubbing equipment for wet scrubbing equipment;
and 3) the production data used in the economic analysis.
Comments Received on the February 1985 Notice
Many of the comments received on the February 1985 Notice were
reiterations of concerns raised on the proposal and first notice.
However, several new issues were raised regarding regulatory
flow rates and cost estimates. These are described below.
Applied Flow Rates. The Agency received comments on the February
15, 1985 notice which questioned the decreases in some applied
flow rates from those published in the March 20, 1984 notice.
The process segments specifically noted as having applied flows
that decreased were as follows: aluminum die casting, aluminum
mold cooling, copper direct chill casting, and zinc die casting.
Other comments questioned applied flow rates for certain other
process segments and stated that they should be increased. These
include the ferrous melting furnace scrubber, ferrous dust
collection, and the zinc melting furnace scrubber process
segments. Applied flow data for specific plants with wet
scrubbers also were questioned.
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Finally, a few commenters stated that cupola melting furnaces
that have been installed recently have been designed with
recuperative energy recovery; they asserted that the normalized
applied flow for these new cupolas is much higher than the
applied flow allowed by EPA for the ferrous melting furnace
scrubber process segment (see Appendix A, February 15, 1985
notice at 50 FR 6579). It was further asserted that additional
flow allowances were necessary for multiple Venturis, quenchers,
after coolers, fan washes, and other ancillary water used in a
scrubber system described by one commenter,
Compliance Costs, The cost comments received on the February 15,
1985notice focused more narrowly on certain aspects of the
costs, such as the cost of monitoring for regulated pollutant
parameters, operation and maintenance labor requirements, and
segregation of noncontact waters front process wastewaters. One
commenter, in reviewing the compliance costs for small plants,
commented that the Agency's model plant investment costs were
correct.
Data Gathering Efforts in Response to Comments on the February
1985 Notice.
Most of the work on the regulation performed after February 15,
1985, focused on properly analyzing the large amount of existing
data and on incorporting the results into the regulation, rather
than on gathering new data. However, two data gathering efforts
were undertaken; these are described below.
The first effort was a result of the Agency's endeavor to develop
treatment effectiveness concentrations based on data from metal
molding and casting plants. The Agency's preference was to base
the concentrations on data from EPA sampling, and on DMR data
which had been confirmed by actual sampling data. An attempt was
made to confirm as much of the DMR data as possible.
After screening the available DMR reports to determine those
plants that have well-operated lime and settle treatment
receiving metal molding and casting wastewater, the Agency sent
letters requesting additional supporting data and documentation
to four plants. EPA requested that each plant submit data from
short-term (three days) sampling and analysis of its treatment
system influent (raw) and effluent. EPA received short-term
sampling data from three of the four plants. One of the four
plants did not sample its wastewaters because the data requested
were already available without sampling. Based upon these data
and documentation, the Agency determined that DMR data for three
of the four plants could be considered confirmed and used in the
development of final effluent limitations and standards. Data
for one of the plants could not be used due to the presence of
excessive quantities of noncontact cooling water commingled with
process wastewaters in the plant's treatment system, The
expanded EPA and confirmed DMR data base, including the data from
these three plants, was used to establish lime and settle
treatment effectiveness concentrations for the final regulations*
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The second data gathering effort conducted after publication of
the February 15 Notice was undertaken as a result of comments
received concerning melting furnace scrubber flow rates,
Comroenters asserted that 1} additional flow allowances were
necessary for multiple stage scrubbers and for scrubbers with
ancillary water use, such as after coolers and fan washing; 2)
recently installed cupolas designed with recuperative energy
recovery or with below-charge gas take-off systems require a
higher applied flow.
In response to these comments, the Agency reviewed available data
and also contacted by telephone several plants, as well as
manufacturers of those cupola systems and manufacturers of
melting furnace scrubbers. The conclusions, reached by data
examination and supported by the vendor contacts, were: 1)
multiple stage scrubbers do indeed require higher applied flow
rates, and 2} the presence of recuperative energy recovery
systems on a melting furnace does not increase scrubber water
requirements significantly. These conclusions were incorporated
into the final regulation.
DESCRIPTION OF THE METAL MOLDING AND CASTING (FOUNDRY) INDUSTRY
The unique feature of the metal molding and casting industry is
the pouring or injection of molten metal into a mold, with the
cavity of the mold representing, within close tolerances, the
dimensions of the finished product. One of the major advantages
of this process is that intricate metal shapes, which are not
easily obtained by any other method of fabrication, can be
produced. Another advantage is the rapid translation of a
projected design into a finished article. New articles are
easily standardized and duplicated by the casting method.
The metal molding and casting industry ranks sixth among all
manufacturing industries based on "value added by manufacturer",
according to data issued by the United States Department of
Commerce in 1979 (Survey of Manufacturers, SIC 29-30). As of
1978, there were over 3,600 commercial foundries in the United
States employing approximately 300,000 workers and producing over
17 million metric tons/year (19 million tons/year) of cast
products. These estimates do not include such establishments as
art studios, trade schools, and coinage mints, which the Agency
does not consider to be commercial facilities.
Plants in this industry include both "job shops" (plants that
sold 50 percent or more of their production to customers outside
the corporate entity) and "captive plants" (plants that sold 50
percent or more of their products internally or were used within
the corporate entity). They vary greatly in metal cast,
production, wastewater source and volume, size, age, and number
of employees.
Annual casting production has ranged between 15 and 20 million
tons during most of the last 20 years. Ferrous castings have
accounted for about 90 percent of the total tons produced
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annually since 1956. Table III-2 presents domestic foundry
shipments by metal type over the past twenty years.
The number of smaller ferrous foundries has dropped dramatically
in the past 20 years, while the number of large and medium size
ferrous foundries has moderately increased. Among the nonferrous
metals, aluminum casting has been increasing whereas the trends
for the other metals are mixed. There is a trend toward a
decreasing percentage of zinc casting shipments compared with
total metal molding and casting shipments and compared to
aluminum casting shipments.
The product flow of a typical metal molding and casting operation
is shown in Figure III-l. In all types of metal molding and
casting plants, raw materials are assembled and stored in various
material bins. From these bins, a "furnace charge" is selected
by using various amounts of the desired materials. This material
is "charged" into a melting furnace and heated until molten. A
system for cleaning the melting furnace off-gases is usually
present and may be either dry (baghouse or electrostatic
precipitator) or wet (scrubber). In ferrous foundries, slag may
be removed intermittently from the melting furnace; the slag is
usually water quenched for granulation to facilitate disposal.
As the metal is being charged and melted, molds are being
prepared. This process begins by forming a pattern (usually of
wood) to the approximate final shape of the product. This
pattern is usually made in two pieces that will eventually match
to form a single piece, although patterns may consist of three or
more pieces. Each part of the pattern is used to form a cavity
in the moist sand media that forms the mold, and the two portions
of the mold (called "cope" and "drag") are matched together to
form a complete cavity in the sand media. An entrance hole
(called a "sprue") provides the proper path for the introduction
of molten metal into the cavity. The mold is then ready to
receive the molten metal. In die casting operations, the mold
cavity is formed in metallic die blocks which are locked together
to make a complete cavity.
The molten metal is now "tapped" from the furnace into the ladle.
The ladle and molds are moved to a pouring area and the metal is
poured into the molds. The molds are then moved to a cooling
area where the molten metal solidifies into the shape of the
pattern. When sufficiently cooled, the sand is removed by a
process known as "shake out." By violent shaking, the sand
surrounding the metal is loosened, falls away, and is returned to
the sand storage area. A dust collection system, using wet or
dry methods of collection, is usually provided in this area. The
sand may be washed and reused. In the case of die casting, where
no sand is used, the cast object is removed from the die casting
machine after cooling sufficiently to retain its shape. The
casting is either further cooled in a water bath or is allowed to
air cool on a runout or cooling table.
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The cast metal object, called a casting, can be further processed
by grinding to remove excess metal. Grinding can be conducted
with or without an auxiliary wet or dry air cleaning systems.
Castings are cleaned by various methods that complete the removal
of the sand and other impurities from their surfaces. These
cleaning operations can include washing with water, or may be
conducted by physical abrasion such as shot blasting or sand
blasting. Dusts generated by shot blasting and sand blasting can
be collected in wet air pollution control devices (dust
collection scrubbers). Depending on the metallurgical properties
desired, some castings may undergo a heat treatment or annealing
step that ends with a water quench.
Process wastewaters from the above described operations are the
subject of the effluent regulations for the metal molding and
casting point source category. About 80 percent of the
wastewater covered by this regulation is generated by wet air
pollution control devices.
All aluminum, copper, ferrous, and zinc casting is covered under
these regulations with the exception of the processes noted
below. The casting of ingots, pigs, or other cast shapes related
to nonferrous metal manufacturing are not included in this
category; these operations are covered under regulations for the
nonferrous metals manufacturing category (see 40 CPR Part 421).
Whenever the casting of aluminum or zinc is performed as an
integral part of aluminum or zinc forming and is located on-site
at an aluminum or zinc forming plant, then the aluminum casting
operation is covered by the aluminum forming regulations (see 40
CFR 467) and the zinc casting operations are covered under the
nonferrous forming regulations (see 40 CFR 471). The casting of
ferrous ingots, pigs, or other cast shapes associated with iron
and steel manufacture is primarily a dry operation involving no
process wastewater and, consequently, no regulations have been
developed covering this operation. The casting of copper-
beryllium alloys where beryllium is present at 0.1 or greater
percent by weight and the casting of copper-precious metals
alloys in which the precious metal is present at 30 or greater
percent by weight are also excluded from regulation in the metal
molding and casting category.
Depending on the final use of the casting, further processing by
machining, chemical treatment, electroplating, painting, or
coating may take place. Following inspection, the casting is
ready for shipment, Wastewaters from these operations are not
covered by this regulation. They may be covered by another set
of effluent regulations (e.g., electroplating) or may be subject
to the permit authority's or municipal facility's best judgment
in applying appropriate effluent limitations or standards. These
processing operations, if not covered under 40 CFR Parts 467 or
471, are covered by effluent limitations and standards applicable
to electroplating and metal finishing. See 46 FR 9462 [January
28, 1981, Part 413] and 47 FR 38462 [August 31, 1982, Parts 413
and 433]. Note that grinding scrubber operations in the
aluminum, ferrous, and copper casting subcategories are covered
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under the metal molding and casting category.
Metals Descriptions
Many of the cast metals have unique properties that influence the
way they are melted and processed and, subsequently, affect the
process wastewater characteristics. A brief description of these
metals, metal molding and casting equipment, and processes is
presented below.
Aluminum
Aluminum is a light silver-white metal weighing 2697 kg/cu m
(168.4 lbs/ft3). It is soft, but possesses good tensile
strength. An aluminum structure weighs half as much as a steel
structure of comparable strength. It melts at 660°C
(1,200°F) and is easily cast, extruded, and pressed. Today
aluminum is the second most widely used metal, after iron. Table
III-2 indicates that in 1984 over 0,9 million metric tons (0.8
million tons) of aluminum castings were shipped in the Dnited
States.
Aluminum may be cast in a variety of ways. A drawing depicting
the process and water flow in a typical aluminum investment
casting operation is presented in Figure III-2. Figure III-3
shows the process arrangement and water flow schematic for a
typical aluminum die casting operation.
Copper
Copper is a red, ductile metal weighing 8956 kg/cu m (559.1
lbs/ft3). It is second to aluminum in importance of nonferrous
metals. It melts at 1,083°C (1,982°P) and has excellent
corrosion resistance. Brass and bronze, which are mixtures of
copper, tin, lead, and zinc, are two of the most important copper
alloys. Other metals used to form copper alloys include
manganese, nickel, silicon, and beryllium. Table III-2 provides
a recent history of copper shipment tonnages.
Copper and its alloys may be cast in a variety of ways, as
depicted in Figure III-4. Figure III-4 also shows the process
and process wastewater flow schematic typical of a copper casting
operation.
Ferrous
Iron is the world's most frequently and widely used metal. Iron
weighs 7870 kg/cu m (491.3 lbs/ft3). When alloyed with carbon,
it has a wide range of useful engineering properties. Alloys of
iron include: gray? ductile, malleable, and steel. Tonnages
shipped are presented in Table III-2. Figure III-5 displays a
typical process and process wastewater flow schematic for ferrous
foundries.
Gray Iron is the most popular of the cast irons. It is
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characterized by the presence of most of the contained carbon as
flakes of free graphite in the iron casting. The tensile
strength of gray iron is affected by the amount of free graphite
present as well as the size, shape, and distribution of the
graphite flakes. Flake size, shape, and distribution are
strongly influenced by metallurgical factors in the melting of
the iron and its subsequent treatment while molten and by
solidification and cooling rates in the mold.
Chemically, gray iron castings include a large number of metals
covering a range of composition, with carbon varying from 2 to 4
percent, and silicon from 0.5 to 3 percent, with small amounts of
nickel, chromium, molybdenum, and copper frequently added.
Ductile Iron (also known as nodular iron or spherulitic iron) is
sinular to gray iron with respect to carbon, silicon, and iron
content, and in the type of melting equipment, handling
temperatures, and general metallurgy. The important difference
between ductile and gray iron is that the graphite separates as
spheroids or nodules (instead of flakes as in gray iron) under
the influence of a few hundredths of a percent of magnesium in
the composition. The presence of minute quantities of sulfur,
lead, titanium, and aluminum can interfere with, and prevent, the
nodulizing effect of magnesium. Molten ductile iron must,
therefore, be purer than molten gray iron. However, a small
quantity of cerium added with the magnesium minimizes the effects
of the impurities that inhibit nodule formation and makes it
possible to produce ductile iron from the same raw materials used
for high grade gray iron manufacture.
The general procedure for manufacturing ductile iron is similar
to that of gray iron, but with more precise control of
composition and pouring temperature. Prior to pouring metal into
the molds (and in some cases during pouring), the metal is
innoculated with the correct percent of magnesium, usually in a
carrier alloy, to promote the development of spheroids of
graphite on cooling.
While the development of ductile iron dates back to the 1920*s,
only within the last 20 years has it become an important
engineering material. This can be noted from Table III-2 which
shows its increasing use.
Malleable Iron is produced from iron, with alloying materials
present in the following ranges of composition:
Percent
Carbon 2.00 to 3.00
Silicon 1.00 to 1,80
Manganese 0.20 to 0.50
Sulfur 0.02 to 0.17
Phosphorus 0.01 to 0.10
Boron 0.0005 to 0.0050
Aluminum 0.0005 to 0.0150
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Low tonnage foundries use batch-type furnaces (e.g., electric arc
introduction or reverberatory). The tapping temperature of the
iron is 1,500°C-1,600°C {2,70Q°-2,9QQ°F)
depending on the fluidity required. In large tonnage shops
needing a continuous supply of molten malleable iron, electric
furnaces or duplexing systems are employed. Cupola furnaces are
common in some malleable shops, especially for the production of
pipe fittings. After the iron casting solidifies, the metal is a
brittle white iron. Malleable iron castings are produced from
this white iron by heat treating processes which convert the as-
cast structure to a "temper carbon" grain structure in a matrix
of ferrite. This is an annealing process requiring proper
furnace temperature/time cycles and a controlled atmosphere.
Steel is the fourth ferrous alloy covered by this regulation.
The making and pouring of steel for castings is similar to the
casting of steel into ingots. One major difference from steel
mill practice is the higher tapping temperature necessary to
attain the correct fluidity, which is needed to pour the steel
into molds. The melting furnaces in foundries are generally of
the same type as those for steel mills but are smaller. Only a
thoroughly "killed" (deoxidized) steel is used for foundry
products. Molding practices are similar to those of gray iron
operations? however, precautions are required for the higher
pouring temperatures—1,800°C (3,200°F). Mold coatings
or washes are used to give a better finish and molds are
generally made of more refractory-like materials to resist metal
penetration. Cast steels generally have the following ranges of
composi tion:
Percent
Carbon 0.20 to 1.00
Silicon 0.55 to 0.80
Manganese 0.60 to 1.20
Sulfur 0.03 to 0.05
Phosphorus 0.035 to 0.06
Magnesium
Magnesium is a silver-white metal weighing 1,751 kg/cu m {108
Iba/ft3}. On an equal weight basis, magnesium is as strong as or
stronger than any other common metal. It can be melted in the
same types of furnaces used for aluminum or zinc. However,
magnesium is a strong reducing agent and is a dangerous fire
hazard, especially when molten. Because of the nature of molten
magnesium, care must be exercised in selecting refractories and
other materials that may contact the molten metal.
Magnesium furnaces are usually of the stationary or tilting
crucible type and are heated by gas, oil, or coreless electric
induction units. The crucibles are made of low carbon steel with
nickel and copper contents below 0.10 percent. Magnesium is
usually alloyed with aluminum, zinc, manganese, or rare earth
metals for foundry work.
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Most magnesium is cast in sand molds. The practice for sand
casting of magnesium alloys differs from most other metals in the
precautionary measures required to prevent metal-mold reactions.
Inhibitors such as sulfur, boric acid, potassium fluoroborate,
and ammonium fluorosilicate are mixed with the sand to prevent
these reactions. Molding sands for magnesium alloys must have
high permeability to permit the free flow of mold gases to the
atmosphere.
Table III-2 indicates the growth of magnesium foundry production.
A general process schematic is presented in Figure III-6.
Zinc
Zinc is a bluish-white metal weighing 7136 kg/cu m (445
lbs/ft3). It has a hexagonal close-spaced crystal structure.
Zinc melts at 420°C (780°F) and boils at a temperature of
907°C (1,665°F). Its low melting temperature, very small
grain size and adequate strength make zinc and zinc alloys well
suited for die casting, which is the process most often used to
shape zinc products. Typical zinc alloy compositions consist of
0.25 percent copper, four percent aluminum, 0.005 to 0.08 percent
magnesium, and traces of lead, cadmium, tin, and iron.
Furnaces used in melting and alloying zinc are usually the pot
type, although immersion tube and induction furnaces are also
used. Good temperature control is a necessity for both melting
and holding furnaces.
Table III-2 indicates the decreasing shipments of zinc castings,
A zinc die casting process schematic is presented in Figure III-
7.
DESCRIPTION OF METAL HOLDING AND CASTING INDUSTRY PROCESSES
After reviewing the data provided in the responses to the DCP
questionnaires, the Agency developed a list of the metal molding
and casting industry operations that generate process
wastewaters. The data presented in the plant survey responses
indicate that the major sources of wastewaters and wastewater
pollutants are the air pollution control devices used in
conjunction with metal molding and casting processes. The
following sections describe the wastewater generating operations
noted in the plant survey data base.
Melting Furnaces
Melting furnace scrubbers contact the gaseous emissions from a
melting furnace with a clean water stream, which removes
particulates, sulfur and carbon oxides from the gaseous
emissions. As a result, these scrubbers generate process
wastewaters contaminated with the pollutants carried by the
furnace emissions. The following melting equipment descriptions
are provided as a basis for discussion of the various types of
scrubbers '> = pd in melting furnace operations.
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Cupola Furnace
The cupola furnace is a vertical shaft furnace consisting of a
cylindrical steel shell, lined with refractory and equipped with
a wind box and tuyeres for the admission of air, A charging
opening is provided at an upper level for the introduction of
melting stock and fuel. Holes and spouts for the removal of
molten metal and slag are located near the bottom of the furnace.
Air for combustion is forced into the cupola through tuyeres
located above the slag well. The products of combustion, i.e.,
particles of coke, aah, metal, sulfur dioxide, carbon monoxide,
carbon dioxide, etc., and smoke comprise the cupola emissions.
In many cases, air pollution emission standards require that
these emissions be controlled. Wastewaters are generated in this
process as a result of using water as the medium for scrubbing
furnace gases.
The cupola has been the standard melting furnace for gray iron.
Figures 111-8 and III-9 illustrate cupola furnace systems.
Electric Arc Furnaces
An electric arc furnace is essentially a refractory-lined hearth
in which material can be melted by heat from electric arcs. Arc
furnaces are operated in a batch fashion with tap-to-tap times of
one and one-half to two hours. Power, in the range of 551-662
kwh/metric ton {500-600 kwh/ton), is introduced through three
carbon electrodes. The molten metal has a large surface area in
relation to its depth, permitting bulky charge material to be
handled. This large surface area to depth ratio is also
effective in slag to metal reactions as the slag and metal are at
the same temperature. Arc furnaces are not generally used for
nonferrous metals, because the high operational temperatures of
the arc tend to vaporize the lower melting temperature metals.
The waste products from the arc melting process are smoke, slag,
and oxides of iron emitted as submicron fumes. Carbon monoxide
and dioxide gases are formed when the electrodes are consumed
during the melting process. Dry air pollution control equipment
such as baghouses are generally used to control electric arc
furnace emissions; however, wet scrubbers may be used. In at
least five instances in the metal molding and casting data base,
wet venturi scrubbers are used to clean emissions from electric
arc furnaces.
Induction Furnaces
Induction melting furnaces have been used for many years to
produce nonferrous metals. Innovations in the power application
area during the last 20 years have enabled these furnaces to be
competitive with cupolas and arc furnaces in gray iron and steel
production. This type of furnace has some very desirable fea-
tures. There is little or no contamination of the metal bath, no
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electrodes are necessary, composition can be accurately con-
trolled, good stirring is inherent, and while no combustion
occurs, very high temperatures are obtainable.
There are two types of induction furnaces: (a) coreless, in
which a simple crucible is surrounded by a water-cooled copper
coil carrying alternating current, and (b) core or channel, in
which the molten metal is channeled through one leg of a
transformer core. The induction furnace provides good furnace
atmosphere control, since no fuel is introduced into the
crucible. As long as clean materials such as castings and clean
metal scrap are used, no air pollution control equipment is
necessary. If contaminated scrap is charged or magnesium is
added to manufacture ductile iron, air pollution control devices
are required to collect the fumes that are generated.
Reverberatory Furnace
A reverberatory furnace operates by radiating heat from the
burner flame, roof, and walls onto the material to be heated.
This type of furnace was developed particularly for melting
solids and for refining and heating the resulting liquids. It is
generally one of the least expensive methods of melting because
the flames come into direct contact with the solids and molten
metal. A reverberatory furnace usually consists of a shallow
refractory lined hearth for holding the charged metal. It is
enclosed by vertical side and end walls, and covered with a low
arched roof of refractories. Combustion of fuel occurs directly
above the charge and the molten bath. The wall and roof receive
heat from the flame and combustion products and radiate heat to
the molten bath. There are many shapes of reverberatory
furnaces, with the most common type being the open hearth style
used in steel manufacture. However, the cost of pollution
control equipment, as well as inefficiencies in handling the
metal, have caused this type of furnace to become obsolete in
steel and gray iron manufacture. Reverberatory furnaces are
still widely used in nonferrous production.
The products of combustion from reverberatory furnaces are con-
ducted to a stack and exhausted to the atmosphere. Contaminants
such as smoke, carbon monoxide and dioxide, sulfur dioxide, and
metal oxides must be removed from the exhaust gases. These
become process wastewater pollutants when scrubbers are used to
clean the combustion gases.
Crucible Furnace
Crucible furnaces, which are used to melt metals having melting
points below 1,900° (2,500°F), are constructed of a
refractory material such as a clay-graphite mixture or silicon
carbide, and are made in various shapes and sizes. The crucible
is set on a pedestal and surrounded by a refractory shell with a
combustion chamber between the crucible and the shell. The
crucible is usually sealed or shielded from the burner gases to
prevent contamination of the molten metal.
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There are three general types of crucible furnaces — tilting,
pit, and stationary. All have one or more gas or oil burners
mounted near the bottom of the unit. The crucible is heated by
radiation and contact with hot gases. The exhaust gases contain
only products of hydrocarbon combustion and generally are not
controlled.
Melting Furnace Air Pollution Control Methods
The preceding discussion on the various types of melting units
used in the remelting of metal describes the source of the furaes,
particulates, smoke and other waste products that comprise
furnace emissions. These emissions constitute a major source of
air pollution and thus must be cleaned before they are released
to the atmosphere. Emissions may be cleaned by either dry air
pollution control methods or by wet air pollution control
methods, also known as scrubbing.
When wet air pollution control equipment, or scrubbers, are used
to control furnace emissions, the contaminated gases are brought
into contact with a scrubbing liquor, usually water. The
particulates and fumes are removed from the gases and enter the
water. Thus scrubbers are a major source of process wastewater.
Dry air pollution control methods do not generate a process
wastewater. The most common types of dry and wet air pollution
control equipment are described in the following section.
Dry Air Pollution Control Methods
Electrostatic Precipitator: Electrostatic precipitation is a
physical process by which a particle suspended in a gas stream is
charged electrically and then, in the influence of an electrical
field, is separated and removed from the gas stream. An
electrostatic precipitation system consists of a positively
charged collecting plate in close proximity to a negatively
charged electrode. A high-voltage charge is imposed on the
electrode, which establishes an electrical field between the
electrode and the grounded collection surface. The dust
particles pass between the electrodes, where they are negatively
charged and diverted to the positively charged collection
plate(s).
Periodically, the collected particles must be removed from the
collecting surface. This is done by vibrating and/or water
washing the surface of the collection plates to dislodge the
dust. The dislodged dust drops into a dust removal system and is
collected for disposal.
Fabric Media (Baghouse): The collection of particulate matter is
achieved by entrapment of the particles in the fabric of a filter
cloth that is placed across a flowing gas stream. These dust
particles are removed from the cloth by shaking or back flushing
the fabric with air. Filtration does not remove from the furnace
exhaust such gaseous contaminants as: carbon monoxide, carbon
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dioxide, phenols, hydrogen chloride, hydrogen sulfide, nitrogen
and its oxides, ammonia, hydrogen, and water vapor. The
quantities of these contaminants depend on the type of fuel,
furnace efficiency, and degree of air infiltration into the gas
stream, Baghouse particulate removal methods have been developed
to a high degree of efficiency (97-99 percent removal of
particulate matter).
The cloth filter media (baghouse) has a temperature limit of
approximately 121°C (250°F). The gases can be cooled to
this temperature by long runs of duct work between the furnace
and the baghouse, The ductwork acts as a radiator to cool the
gases. Such systems are completely dry operations,
Other installations have quench towers between the furnace and
the baghouses. In the quench tower, the hot gases encounter a
water spray. The water evaporates, thereby cooling the hot gases
prior to their entry into the baghouses. This quench chamber
usually is arranged to provide a sharp reversal in the direction
of the gas stream and a sudden reduction in flow velocity. These
features, coupled with the cooling effect achieved by the
evaporation of the water, cause the larger dust particles to be
deposited at the bottom of the chamber, from which they are
periodically removed. The gases then flow to the filter chamber.
Although the primary purpose of a quench tower is to cool the
furnace off-gases, the water spray also absorbs many of the
gaseous contaminants listed above, which are not removed in a
baghouse. Quench towers are also used in conjunction with
electrostatic precipitators. If water does not fully evaporate
and is discharged from a quench tower, the quench tower would be
considered to be a wet air pollution control device.
Wet Air Pollution Control Methods
Wet air pollution control devices, or scrubbers, remove
particulates and fumes from contaminated gases by bringing the
gases into contact with a scrubbing liquor, usually water. There
are many different types of scrubbers; several of the most common
are discussed below.
Venturi Scrubber: This scrubber consists primarily of a Ventura
tube fitted with spray nozzles at the throat. The dust-laden
gases flow axially into the throat, where they are accelerated to
61 m/sec {200 ft/sec). Water is sprayed into this throat by a
ring of nozzles. This produces a dense, mist-like water curtain.
The water droplets in this curtain entrap the dust particles. In
the subsequent diffiiser, the velocity is reduced and inertia is
used to separate the droplets from the gas stream. Venturi
scrubbers require 15-100 inches (water) of pressure drop across
the gas stream. They are very effective on particulate matter in
the range of one micron and readily adsorb many furnace gases,
thus adding many pollutants to the process wastewaters.
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^ The "wet cap" method is an attempt to reduce the
paTticulate emissions in waste gases by passing them through a
water stream or water curtain. This method, operated with a low
pressure drop, can be added to existing cupolas with only minor
changes to equipment and operations. Figure III-9 depicts this
method.
Washing Coolers: Several general designs of washing coolers are
used; however/ all provide some means of securing a long
retention time to keep the gases in contact with the scrubbing
liquor. In general, these units consist of a large cylindrical
vessel with the gases entering tangentially at the bottom and
exiting through the top center. Several levels of sprays bring
the scrubber liquor into contact with the rising gases. The
bottom is usually conical, with a large pipe outlet to return the
dirty liquor to a settling area.
Packed Tower: Another type of scrubber, known as the bulk bed
washer or packed tower, contains water-sprayed gravel beds. The
gases enter in a downward or tangential direction, which results
in preliminary dust removal due to inertia. The aases then flow
upward through a wetted gravel bed. At the upper -face of this
bed, the gas velocity creates a turbulent water zone that brings
the finest dust particles into contact with the water. The
scrubbing liquid is sprayed above this gravel bed and continually
washes it. The liquid is removed at the bottom of the gravel bed
and may be either recirculated or discharged. Above the spray
heads is a droplet catcher that removes the droplets from the
rising gas stream. This scrubbing method requires approximately
10 inches (water) of pressure drop and is not effective on
particles smaller than one micron.
Figure III-8 illustrates a packed tower scrubber. The figure
also illustrates one method of recovering some of the heat from
the gas stream.
Dust Collection and Grinding Scrubbing Equipment
Foundries that use sand as a molding media must collect and
control the dusts produced in handling and using this sand.
Sand, as used in metal molding, is mixed with one or more
materials that coat the sand grains and act as a binder to hold
the sand in the form of the pattern. These binders are a major
source of organic pollutants in metal molding and casting
operations. Fumes and odors result from core and mold making, as
well as from the pouring of hot metal into the molds. The
cleaning of the castings to remove traces of sand, gates,
runners, heads, mold flashings, and mismatch also produce dust
and fumes which are removed from the work place.
Many of these dusts are collected on fabric media in baghouses
such as those described above. In many instances, it is more
economical or more efficient to remove these airborne particles
by entrapping them in a spray or mist. The more common types of
"wet dust collectors" are examined below.
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Spray Chambers
The simplest type of wet scrubber is a chamber in which spray
nozzles are placed. The gas stream velocity decreases as it
enters the chamber. The particles are wetted by the spray,
settle, and are collected at the bottom of the chamber.
Cyclone Scrubbers
Cyclone scrubbers feature a tangential inlet to a cylindrical
body. Water is injected through spray nozzles which break the
water into many droplets. These droplets contact the particles
and decrease their velocity, with the result that the particles
impinge on the vessel sides and are flushed to the bottom. The
clean gases then exit through the top of the scrubber. Baffles
in this exit collect and aid in the removal of the water droplets
from the gas streams.
Orifice Scrubbers
Orifice scrubbers utilize the velocity of the gas stream to
provide liquid contact. The flow of gases through a restricted
passage partially filled with water causes the dispersion of the
water into many droplets that intimately contact and wet the
airborne dusts and absorb some of the gaseous contaminants.
While the amount of water in motion is large, most of the water
can be recirculated without pumps.
Mechanical-Centrifugal Scrubbers
A spray of water at the inlet of a fan becomes a mechanical-
centrifugal collector. The collection efficiency is enhanced by
the entrapment of dusts on the droplet surface and the
impingement of the droplets on the rotating blades. The spray
also flushes the blades of the collected dusts. However, this
spray can substantially increase corrosion and wear on the fan.
Another type of mechanical collector uses a rotating element to
generate a spray of water droplets into a dust laden gas stream.
The wetted particles flush to a collection pan where they can
settle while the water is recirculated.
Venturi Scrubbers
Venturi scrubbers have been described in the section on melting
furnace scrubbers. They are also used in dust collection
systems. In some cases there is a single large Venturi in the
dust-laden air stream with low pressure water added at the
Venturi throat. The extreme turbulence breaks the water into a
fine spray that impacts and wets the dust particles.
Other applications are similar to orifice-type scrubbers/ but
with the Venturi's shape replacing the orifices. These Venturis
are located at the water line and, consequently, water is drawn
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into the Venturi throat where it is broken into a fine spray by
the turbulent air. The spray droplets wet the dust particles and
are impinged against baffle plates and drain to the reservoir.
Packed Towers
This device is similar to the bulk bed washer described in the
melting furnace scrubber section. The dust-laden gases pass
through a bed of granular or fibrous collection material. Liquid
is continually flushed over the surface of the collection
material to keep it wet and clean, and to prevent re-entrainment
of the particles. Collection efficiency depends on the length of
time the gas stream is in contact with the collecting surfaces.
The collecting material should have a large ratio of area to
weight and be of a shape that resists close packing. Coke,
broken rock, glass spheres, and Raschig rings are materials that
are often used as tower packing materials.
A cone-shaped bottom aids in removing settled dust particles from
the liquid, while mist eliminators located in the exit gas-stream
reduce the loss of the flushing liquor. Recirculation of the
liquor is usually practiced,
Wet Filters
A wet filter consists of a spray chamber with filter pads
composed of glass fibers, knitted wire mesh, or other fibrous
materials. The dust is collected on the spray pads as the dust
laden gas stream is drawn through the pads. Sprays directed
against the pads wash the dusts away. The water drains to a
reservoir, where it is settled or clarified and then recirculated
or discharged,
Casting Methods
Foundries use several methods to cast molten metal into its final
shape. These methods are described below, along with the sources
of process wastewater associated with each method. In general,
intimate contact between molten metal and water is avoided
because of the potential development of explosive forces caused
by a too rapid generation of steam. Thus, process wastewater is
usually generated by the cleaning or cooling of partially cooled
castings, as well as hydraulic oil or noncontact cooling water
leakage.
Sand Casting
Green Sand Castings: This is the most widely used molding
method. It utilizes a mold made of compressed, moist sand. The
term "green" denotes the presence of moisture in the molding sand
and that the mold is not dried or baked. This method is usually
the most expedient, but is generally not suitable for large or
very heavy castings.
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Dry Sand Castings: Host large and very heavy castings are made
in dry sand molds. The mold surfaces are given a refractory
coating and are dried before the mold is closed for pouring.
This hardens the mold and provides the strength necessary to
contain large volumes of metal. Molds hardened by the CO2
process may also be considered in this category. Such molds are
not dried, but are made from an essentially moisture free sand
mixture containing sodium silicate. The mold is rapidly hardened
by the reaction of carbon dioxide gas with the silicate. The
process can also be used for making cores.
Shell Hold Castings: This method is of recent development and
utilizes the unique process of making molds by forming thin
shells of a resin-bonded sand over a hot pattern. It is suitable
for small and some medium-sized castings. Shell molding provides
improved accuracy and surface finish, thus allowing greater
detail and less drift than would normally be expected in green
sand molding. Metal patterns of special construction are
necessary. The process is of particular advantage when it
provides savings in machining and finishing. The shell process
has also been very effectively applied in making cores, which may
be used with any of the molding methods.
Core Mold Castings: Castings of unusual complexity (such as the
thin and deep fins of an air-cooled engine cylinder) may be
produced in a mold made of the type of sand commonly used for
cores. This sand has almost free-flowing properties when it is
packed around the pattern, and it will fill crevices and
reproduce detail. After baking/ the mold becomes strong enough
to resist the forces of flowing molten metal. Core sand molds
may be used when complexity requires more than one parting line
in a casting. Core sand sections may be used to form a complex
external portion of a casting in either a green or dry sand mold,
just as cores are used to form internal surfaces.
Permanent Mold Castings: Certain types of iron castings can be
produced in large numbers from mechanically-operated permanent
iron molds. This mechanized, high-production process is mainly
used for castings of suitable shape, of less than 11.4 kg (25
pounds) in weight, and with 0.48 cm (3/16") minimum wall
thickness. Cores are formed with conventional sand or shell
cores.
Ceramic Hold Casting; Certain highly-specialized castings
requiring an unusually fine finish, precise detail, and close
tolerances are produced in molds made of fired ceramics. Pattern
equipment is generally of a "core-box" type, and may be made of
metal or plaster. In some applications, backdraft or undercuts
are allowed by making part of the pattern of a flexible material.
When the mold can be assembled from a number of pieces, castings
of several hundred pounds in weight and several feet in a major
dimension can be made to relatively close tolerances.
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Centrifugal Casting Operations
Centrifugal casting includes a number of different processes in
which the mold rotates at high speed, setting up a centrifugal
force. This force is used to fill the mold, shape the casting,
and help solidify and strengthen the metal. There are two types
of centrifugal casting: vertical and horizontal. Vertical
casting employs rotation around a vertical axis to provide pres-
sure which forces the molten metal into a mold. It provides good
filling of the mold, high dimensional accuracy, and a dense
structure in the casting. Components with very thin sections are
difficult to produce by static means and thus vertical
centrifugal casting is often used. Such components include
gears, piston rings, impellers, propellers, bushings, etc.
Horizontal centrifugal casting is widely known as a method of
producing pipe, but it is also used for a variety of other long,
hollow castings such as engine cylinder liners, process rolls and
gun barrels. In this method, the mold rotates at high speed
around a horizontal axis. Molten metal is fed into the interior
of the mold and is distributed around it by centrifugal force.
The external diameter of the casting corresponds to the internal
diameter of the mold; however, no core is used,so that the inter-
nal diameter of the casting varies with the amount and feed rate
of molten metal. This produces a sounder and more uniform
casting than static means.
Investment Casting Operations
In the investment casting process, an expendable pattern of the
desired product is shaped of wax or plastic. The pattern is then
surrounded by a ceramic slurry or backup material that hardens at
room temperature. The expendable pattern is then melted out,
leaving a very precise cavity in the ceramic material. This is
also called the lost wax process.
After the wax pattern is melted out, all moisture in the ceramic
backup material is eliminated in an autoclave where temperature
can be closely controlled. Molten metal is then poured into the
mold and allowed to cool. Finally, when the metal has solidi-
fied, the mold is broken away to reveal the casting. Final
cleaning is accomplished by high pressure water jets in a hydro-
blast cabinet. This is a source of process wastewater.
Direct Chill Casting
In direct chill casting/ molten copper is tapped from the melting
furnace and flows through a distributor channel into a shallow
mold. Noncontact cooling water circulates within this mold,
causing solidification of the copper. The base of the mold is
attached to a hydraulic cylinder which is gradually lowered as
pouring continues. Ag the forming ingot leaves the mold it is
sprayed with contact cooling water. The cylinder continues to
travel down into a tank of water, which further cools the ingot
as it is immersed. When the cylinder has reached its lowest
71
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position, pouring stops and the ingot is lifted from the pit.
The hydraulic cylinder is then raised and positioned for another
casting cycle.
In direct chill casting, lubrication of the mold is required to
ensure proper ingot quality. Much of the lubricant volatilizes
on contact with the molten copper but contamination of the
contact cooling water with oil and oily residues does occur.
broken up
mold
Dies
Die Casting
In sand casting and investment casting, the mold is broke
after each casting operation. In die casting, however, the
or "die" is made of metal and can be used many times. Dies
produce castings of high dimensional accuracy, with smooth and
clean surfaces.
Three types of die casting can be distinguished, depending on the
type of force used to drive the metal into the mold: gravity,
pressure, or vacuum. For simple gravity castings, the metal may
be poured into the die from the top. However, for most gravity
castings, the die is a closed and complex assembly and such
devices as cores, gates, and risers are employed. Pressure die
casting forces the molten metal into a mold under considerable
pressure, making possible the production of large numbers of
intricate castings at a rapid rate. Vacuum die casting is less
widely used; in this process, air is evacuated from the die,
which sucks the metal in and compacts it.
In most die casting operations, the major sources of wastewaters
are the die casting machine hydraulic oil leakage, mold cooling
water leakage, casting quenches, and mold lubricant spray. Often
these wastewaters are collected around the machine base and are
contaminated by dirt and oil and grease from various fittings.
The application of lubricants to the die cavity is a necessary
and often critical process. Lubricants prevent a casting from
sticking to the die, and also provide a better finish to the
casting. The correct lubricant will permit metal to flow into
cavities that will not otherwise fill properly. A secondary
function of a lubricant is cooling of the die.
When molten metal contacts an oil type lubricant, some of the
lubricant decomposes and leaves a carbonaceous powder on the die
surface. This can be removed from the die surface with an air
jet. Moving die parts, such as ejectors and cores, must be
treated with a high temperature lubricant to prevent seizure.
Oil suspensions of graphite are usually used on these moving
parts. Many of these compounds are carefully developed for
specific machines and represent a considerable expense. The
recovery and reclamation of these materials is an important phase
of the die casting operation. Several plants have segregated
their waste streams and employ die lubricant recovery processes.
72
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Casting Cleaning
During the casting process, many impurities adhere to the cast
product. These impurities include sand/ die lubricants, mold
lubricants, and metal dusts. The final product may be cleaned of
these impurities through use of a water spray or other
application of water. The water used for cleaning becomes
contaminated with these impurities and is considered a process
wastewater.
Casting Quench
Casting quench operations involve the immersion of a casting in a
water bath that sometimes contains additives. Quenching may be
performed for two reasons: 1) to solidify the casting more
quickly, or 2) to obtain certain desirable metal grain structures
that result from rapid thermal changes.
Casting quench is most commonly associated with die casting
operations in which a completed casting is ejected from the die
and falls immediately into the quench bath. This is done
primarily to solidify the metal quickly, reduce the machine cycle
time, and increase production.
Many aluminum die casting plants have replaced the quench with a
runout table on which the castings air cool. This eliminates the
generation of the process wastewater associated with quenching.
However, depending on the configuration of the casting, zinc
castings may sag if allowed to air cool. Thus the trend to
eliminate quenching is not as prevalent in zinc die casting
operations.
Mold Cooling
When permanent molds are used in the casting process, it is often
necessary to cool the molds with water sprayed or flushed over
them. This water becomes a process wastewater and contains
contaminating materials picked up from the molds. Mold cooling
can also be accomplished by internal circulation of water through
the mold. This water is considered to be noncontact cooling
water and thus is not covered by this regulation unless it leaks
or is otherwise allowed to commingle with process water.
SLag_ Quench
In most melting operations, a mixture of non-metallic fluxes is
introduced into the furnace along with the metal charge. This
mixture acts as a scavenger to remove impurities from the molten
metal. The flux and impurities thus produced are removed from
the molten metal as "slag" or "dross," After removal, the slag
is cooled for disposal or reclamation. In ferrous foundries, the
amount of slag produced requires disposal on a large scale.
Where the slag is continuously produced {i.e., in a cupola
operation), it is quenched in a water stream to rapidly cool and
fragmentize it to an easily handled bulk material. The quench
73
-------
water is a process wastewater.
In nonferrous metal molding and casting plants, the slags
generated are considerably smaller in volume and mass than those
generated in ferrous foundries and are handled without producing
a process wastewater,
Sand Reclamation
In the many plants that use sand as a molding medium, the
reclaiming and reuse of the sand is a major operabion. Three
methods of reclaiming sand are in general use: dry, wet, and
thermal.
The dry methods generally include screening, lump breaking, and
cooling before reuse. These processes usually produce a dust
from the handling of the sand/ but no process wastewaters result
unless a wet dust collector is used.
The wet method has several variations. Generally, a slurry is
made of sand and water. Agitating or stirring this slurry causes
the sand grains to scrub against each other and remove the
particles of burnt clay, chemical binders, sugar, wood fiber,
etc., which may adhere to the sand grains. The slurry is pumped
to a classifier for separation of the fine grain materials. The
sand is then dried.
The thermal method involves heating the sand to 649-816°C
(1,200-1,500°F) in air to remove carbonaceous material. Some
clay may also be removed by abrasion of the sand grains as they
travel through the process. The thermal reclamation process does
not produce a process wastewater.
The wash water used in wet reclamation contains considerable
contaminants in the form of fine silicate material, spent clay,
and other pollutants. To economize on water use, this water can
be clarified and returned to the sand washing system. Several
examples of water reuse from wet sand reclamation processes are
found in the DCP data base.
Grindjjig Scrubber
Dusts produced in sawing, grinding, or rough or preliminary
machining of metals are collected in a scrubber. As in other
dust scrubbers, a water spray coats the dust laden-gas stream,
and wets the metal dust particles, which then settle.
Scrubbers of grinding or sawing dusts can be of several types, as
previously described. Where practicable, the dust from such
metal working operations can be salvaged and remelted.
74
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Magnesium Grinding Scrubbers;
Finely divided particles of magnesium can react violently in air.
It is mandatory that magnesium dusts be wetted to prevent this
reaction. Therefore, all dusts produced in sawing, grinding, or
rough or preliminary machining of magnesium are collected in a
scrubber. The water spray coats the dust-laden gas stream and
wets the magnesium particles, eliminating the fire hazard.
Magnesium grinding scrubbers are similar to other dust scrubbers.
PROFILE OF PLANTS IN THE METAL HOLDING AND CASTING POINT SOURCE
CATEGORY
The profile of the metal molding and casting industry is based
upon the technical data furnished to the Agency by plants engaged
in metal molding and casting operations. The industry profile is
organized into the following five topics. The discussion of each
topic follows:
1. Distribution of wet and dry plants
2. Process wastewater profile-flow and discharge mode
3. Production profile
4, Production equipment age and treatment equipment age
5, Land availability for installation of treatment
equipment
Distribution of Wet and Dry Plants
Analysis of the survey data reflective of 1976 and the updated
survey conducted in 1981 indicated that an estimated 3,853 plants
will manufacture castings applicable to this point source
category in 1986. One thousand-fifty-nine (1,059), or 27
percent, operate manufacturing processes that result in the
generation of a process wastewater. These are considered "wet"
plants. Of those 1,059 wet plants, 301 discharge directly to
surface waters and 499 discharge indirectly to POTWs. The
remaining 259 plants have no discharge of process wastewater -
either they recycle 100 percent of their wastewater, or the
wastewater is contained in an on-site impoundment.
Plants that produce no process wastewater are considered to be
"dry" plants. Two thousand seven hundred ninety-four (2,794) of
the 3,853 active metal molding and casting plants are dry. This
distribution is presented below:
75
-------
Number of Plants
Type o£_ Plant ^n the Category
Wet Plants:
Direct Dischargers 301
Indirect Dischargers 499
Zero Dischargers 259
Total Wet Plants: 1,059
Dry Plants: 2,794
Total MM&C Plants: 3,853
(Wet & Dry)
The distribution of wet and dry plants by major metal cast and
employment size group is presented in Table III-3. Following is
a summary of the data presented in this table.
Type of Percent of the Plants Casting This
Metal Cast Metal That Generate a Process Wastewajier*
Aluminum 11.6
Copper 11.0
Ferrous 47.1
Magnesium 58*3
Zinc 21.7
*Based upon 1980 operations.
The Agency has determined, as shown on Table III-3, that 73
percent of the plants in the category are dry, while 27 percent
of the plants are wet.
Table III-4 presents the percentage of wet operations in each
employment size group in each subcategory. This table indicates
that smaller metal molding and casting operations, as
distinguished by the number of employees, are less likely to
generate a process wastewater than the metal molding and casting
plants in larger employment size groups. This trend is
illustrated below,
Employment Percent of Active Plants in
Size GjT>up Each Gjroup that are Dry
<10 98.7
10-49 84,0
50-249 51.4
<250 22.5
The main reason for the trend noted above is the different air
pollution requirements for plants of various sizes. The small
metal molding and casting plants still in operation are generally
job shops that do not require large capacity production
equipment. As a result, the air pollution impact from these
shops is much smaller than from large production facilities, and
76
-------
for economic reasons, baghouses are preferred for emission
control where required. Melting furnaces typically are small and
are not required to have scrubbing devices in many states. In
addition, most sand handling activities in small shops are
performed by hand and, subsequently do not produce the large
volume of dust associated with mechanical sand handling
equipment. Therefore, many of the small plants have not
installed wet air pollution control devices to control air
emissions for these operations.
Process Wastewater Profile - Flow and Discharge Mode
About 318.5 billion liters {84,1 billion gallons) of metal
molding and casting process wastewater are generated each year
186.3 billion liters (49.2 billion gallons) generated by
processes which discharge to navigable waters, and 132.2 billion
liters (34.9 billion gallons) generated by process which
discharge to publicly owned treatment works. The complete
distribution of foundry process wastewaters is presented below.
Distribution of Process Wastewaters
Subcategory
Aluminum
Copper
Ferrous
Magnesium
Zinc
Total
Amount
Generated by
Direct
Dischargers
(106 gal/yr)
1,448
10,240
37,290
0.1810
244.6
49,230
Amount
Generated by
Indirect
Dischargers
(106 gal/yr}
957.3
1,766
31,650
2.47
530.2
34,910
Percent of
Total Category
(106 g/yr) Total
2,406
12,010
68,950
2.65
774,8
84,140
2.9
14.3
81.9
0.003
1.0
100
dk 111= ^UJiS^U
wastewater
The subcategories ranked in decreasing volume of total process
generated are: ferrous casting, copper casting,
-'•- ' n ' - ' * Process
uus ^dHLiiiy, ^uppec ua being
casting, and magnesium casting. Process
direct discharging ferrous plants
.he total volume of water generated by
jategory. Similarly, 91 percent of
of process wastewaters generated by plants that
by
of
the
TTU4t*^-TTW.^»^4. u*_ti^l_
aluminum casting, zinc
wastewaters generated
account for 76 percent
direct dischargers
Lf I 1 C lm U t ^i J- V U -L LlIllC *tJ -^ £* ± \J Tmf ^* *J kJ TV U 0 "" *v TT V4 \* ^- J- *J ^ C 1 i *» i, ^4 ^
discharge to POTWS results from the casting of ferrous
A more detailed process wastewater flow profile
Section V.
Production Profile
is
metals.
presented in
For the purposes of this document, the term production is used to
express the mass of metal poured and not the weight of finished
castings produced by, or shipped from, those plants within the
metal molding and casting point source category.
77
-------
An estimated 55.2 million metric tons {60.8 million tons) of
metal are poured annually in plants which generate a process
wastewater in their metal molding and casting processes.
Approximately 29.7 million metric tons {32.8 million tons) of
metal are poured annually in plants discharging process
wastewaters directly to navigable waters. Ten million metric
tons (11 million tons) of metal are poured annually in plants
which introduce process wastewaters into POTWs, An estimated
15.4 million metric tons (17.0 million tons) of metal are poured
in plants which do not discharge process wastewaters (or 28
percent of the total annual amount of metal poured). This
distribution is presented below.
Distribution of Foundries Production
(Millions of metric tons) Percent
Type of Plant Prc?duc^t^ion of Tg_tal_
Indirect Dischargers 10 18
Direct Dischargers 29,7 54
Zero Dischargers 15.4 28
All Wet Foundries 55 100
In determining the estimate for "no discharge" operations, only
the weight of metal poured at plants which do not discharge
process wastewaters from any metal molding and casting process
was considered. For example, the weight of metal poured at a
plant with one process which did not have a wastewater discharge
and one process discharging to a POTW was included in the
estimate for the POTW discharge group.
For those plants that generate process wastewater, 65 percent of
all the metal melted is poured in 25 percent of the plants.
Ninety-seven percent of the metal poured in these wet operations
is ferrous metal; Gray iron represents 70 percent of the total
weight of all ferrous metal poured.
Production Ec^uijpmerU: and Treatment Equipment Age
The treatment technologies chosen as the basis of this regulation
are applicable to both old and new plants. This assertion is
supported by several observations about the metal molding and
casting industry data base.
As discussed earlier, plants in the data base appear to have a
wide range of ages in terms of initial operating year* The
general plant summary tables in the record for this rulemaking
present each plant's age in terms of its oldest melting furnace
as well the age of its treatment systems. However, plants must
be frequently modernized in order to remain competitive. Plants
78
-------
may be updated by modernizing a particular component, or by
installing new components. For example, an old furnace might be
equipped with oxygen lances to increase the throughput, or it
might be replaced entirely by a new, more efficient furnace.
Modernization of production equipment and air pollution control
equipment produces similar wastes among all plants producing a
given metal by a given process. It follows that similar
wastewater treatment technology can be applied to these similar
wastes.
An examination of the metal molding and casting data base shows
that some foundries have operated at the same location for over
100 years, but have replaced melting furnaces as recently as five
years ago, and have replaced sand handling systems as recently as
ten years ago. Although the age of the plant is over 100 years,
the wastewater generated would be analogous to that of plants
built more recently, and the discharges would be equally amenable
to treatment.
In addition, metal molding and casting industry data indicate
that about half of the plants in the data base installed process
wastewater treatment equipment five or more years after the
installation of the oldest melting furnace, In fact, nine
percent of the ferrous foundries in the data base installed
process wastewater treatment equipment as long as 30 years after
the installation of the oldest melting furnace. This further
supports the observation that the age of a plant has no
correlation with the plant's ability to install water pollution
control equipment.
Land Ayailabi 1 ity for the Install ation of Wastewater Treatment
Equipment
In the DCP surveys, the Agency requested that the plants provide
information on the amount of land available for the installation
of wastewater treatment equipment. About 90 percent of all the
respondents to the question on the DCP reported that sufficient
land was available for the installation of wastewater treatment
equipment.
Of the ten percent that did express some concern regarding land
availability, one third reported that no process wastewaters are
discharged from their plants. The installation of additional
treatment equipment would not be necessary for such plants as a
result of this regulation. Many of the remaining plants already
have wastewater treatment equipment in place equivalent to BPT
and BAT technology. Thus, the availability of land for the
installation of treatment equipment is not a serious concern for
the vast majority {>95 percent) of the plants in the metal
molding and casting category.
79
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CO
o
Ductile Iron
Gray Iron
Malleable Iron
Steel
Aluminum
Brass and Bronze
(Copper Alloy)
Magnesium
Zinc
Other Metals
Table III-1
PENTON FOUNDRY CENSUS INFORMATION
Lesa Than
10 Employee^
28
149
11
45
843
533
30
225
150
10-49
Employees
127
489
20
177
1,016
714
50
289
158
50-249
283
579
42
337
450
277
42
175
59
Greater Than
250 Employees
98
156
37
97
75
37
8
39
9
-------
Table III-2
FOUNDRY SHIPMENTS IN THE UNITED STATES
Shipped (Thousands oi' Tonal
Isar
1966
1967
1966
1969
1970
1971
1972
1973
1974
1975
1976
1977
1976
1979
1980
1981
1982
1983a
19B4a
Gray
Iron
13,166
11,097
11,697
12,336
11,728
13,191
11,801
11,459
10,621
11,935
12,291
12,521
12,511
9,399
9,610
6,393
7,180
8,207
Ductile
Iron
863
1,033
1,251
1,607
2,111
1,835
2,216
2,202
1,821
2,213
2,702
2,868
2,690
2,100
2,191
1,822
2,067
2,661
Malleable
Iron
1,131
1,00?
1,172
852
881
960
1,031
914
730
816
829
816
715
150
122
281
291
365
£ii£i
1,857
1,730
1,897
1,724
1,583
1,609
1,891
2,090
1,937
1,803
1,718
1,862
2,039
1,878
1,713
1,017
729
963
Aluminum
827
744
807
865
771
808
958
483
929
728
986
1,077
1,113
1,151
815
910
803
911
819
Copper
523
127
139
i|B1
110
120
160
182
128
350
341
351
372
363
296
290
228
2?6
239
Haftnesium
23
21
21
22
18
27
25
27
29
19
27
29
25
11
13
11
9
12
6
lina
515
113
166
188
398
425
169
510
"121
356
134
391
380
332
243
236
203
258
162
Total
Amount Shipped
IThoiiaanda of Tona)
18,952
19,600
20,876
18,118
17,986
19,BIO
21,50i|
2t,172
16,565
18,615
19,391
19,990
20,0118
15,52i|
15,113
10,759
11.721
13,125
Estimate based on data for shipments In January through November of 1981,
References: U.S. Department of Commerce, Bureau of the Census: "Current Industrial Reports: Nonferroua Castings,
Summary for 1983," HE33E(83)-13; "Iron and Steel Foundries and Steel Ingot Producers, Summary for 1983,"
(HE33A(83)-13); "Konferroua Castings, Hovember 198«,» -11).
-------
Table III-3
DISTRIBUTION OF WET AND DRY PLANTS
METAL MOLDING AND CASTING INDUSTRY
00
ro
Siibcqtcyory
AlucBlmjM Casting
Copper Casting
Ferrous Casting
Magnesium Casting
Zinc Casting
TOTAL
Less
10 |mi
Mfi±
13
27
6
1
-3
50
Than
fiat
163
205
123
5
J3
879
10-19
Hfci
103
52
114
4
J£i
296
Bjcy...
172
272
113
6
^Jul
1,286
50-99
Employees
Hfii firy
33
29
126
2
•js
205
109
18
197
2
_2Jj
382
100-2«9
Employees
62 52
15 12
231 99
0 0
_2-2 _12
333 175
More
Than 250
Mil Bo
21 23
10 0
137 «7
0 3
__J -3
175 76
Total
232
133
6,7
7
7JJ
1,059
. Dry
1,119
537
909
16
an
2,798
-------
Table III-4
PERCENTAGE OF ACTIVE "WET" OPERATIONS WITHIN EACH EMPLOYEE GROUP
METALS CASTING INDUSTRY
Suboategorv
Aluminum Casting
Copper Casting
Ferrous Casting
Magnesium Casting
Zinc Casting
Leas Than
10 Employees
2.7%
11.6%
4.7*
16.7*
5.8*
10-49
17.9%
16.0%
20.5%
40.0%
19.8%
59-99
? Employees
23.2%
37.7%
39.0%
50%
36.6*
100-249
Employees
54.4%
55.6%
70.3%
—
64.7%
More
Than 250
Employees
47.8%
100%
74.5%
0.0%
70%
-------
POUR
I
COOLING
I
SHAKCOUT
CASTING
M HEADS a
""_•
6ATES
-OFF
1
CLEANING
I
iHSPCCTIHQ
1
FINISHING
I
PRODUCT
TO INVENTORY
UOLO
CORES
SAND RECLAIMING
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
PRODUCT FLOW DIAGRAM
FIGURE
-------
CERAMIC
BACK- UP
MATERIAL
50
Ul
SOLIDS TO
LANDFILL
WATER
DISCHARGE
CASTINGS TO
FINISHING
DEPARTMENT
SOLIDS TO
LANDFILL
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
INVESTMENT FOUNDRY
PROCESS FLOW DIAGRAM
FIGURE m-2
-------
DitchwflU or
fl*cyck
Oil
DilfMMflt
Landfill
ENVIRONMENTAL PROTECTION AGENCY
fOUKOHT IHOOS1HV STUDY
'ALUMINUM CHE CAST INS
PROCESS FLOW DIAGA&M
. 9/T/79
I I
IGURE Itt-3
-------
00
WaUr
Pig
WELTING FURNACES
{Multipii Units)
CONTINUOUS
CASTING
SHEET, STHIP, BAR, ROD
8 WIRE MILLS
(Noit-F
-------
To
LtndMI
Sand Return Syilwn
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUOV
FERROUS FOUNDRY
PROCESS FLOW DIAGRAM
Own 5/B/?9
iFIGURE m-5
-------
E nhouvl
of Oitcharj)*
Jo Land! it!
ENVIRONMENTAL PROTECTION AGENCY
FOUNO«Y INDUSTRY STUDY
MAGNESIUM FOUNDRY
PROCESS FLOW DIAGRAM
Own, S/*/ r»
-------
•Wot«r
O
DISCHARGE OR
RECYCLE
TO RMISHiMC
DOMTUEMT
OIL.
OiiKtSAL
ENVIRONMENTAL PROTECT**^ AGEMCY
FOUNDRY INDUSTRY STUDY
2 IMC DIE CASTING
PfiOCESS FLOW
1 I
me-7
-------
Stock
STORAGE
BINS
COMBUSTION
AIR BLOWER
CUPOL*
•EXHAUST GASES
BLAST AIR
To
Cooling
Towir
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
IRON FOUNDRY CUPOLA
TYPE ill
PROCESS FLOW DIAGRAM
E=t
FIGURE nr-8
-------
WET CAP
DRAG TANK
WET OUST
REMOVAL
SYSTEM
* ENVIRONMENTAL PROTECTION A6ENGV
FOUNDRY MtOUSTMY STUDY
IRON FOUNDRY CUPOLA
TYPE 11
PROCESS FLOW DIAGRAM
Dm. 9/Z3/T9
IFIGURE m-9
-------
Section IV
INDUSTRY SUBCATEGORIZATION
INTRODUCTION
The metal molding and casting (foundry) point source category
includes a large number of plants which use a variety of metal
molding and casting techniques to cast several different metals.
Foundries may employ different manufacturing processes, some of
which require air pollution control devices. Both the
manufacturing processes and the air pollution control devices can
generate process wastewaters. There is sufficient variation in
the types of metal cast and the manufacturing and air pollution
control processes employed at metal molding and casting plants to
warrant division of the category into subcategories for
regulatory purposes. The metal molding and casting category is
not amenable to a single set of effluent limitations guidelines
and standards applicable to all plants in the category because of
differences in water use requirements and raw waste
characteristics.
This category is, however, amenable to a subcategorization scheme
which provides for the grouping of metal molding and casting
plants which: cast similar metals, employ similar manufacturing
processes, have similar sources of air pollution control, and, as
a result, have similar water use requirements and generate
wastewaters with similar characteristics. An appropriate
subcategorization scheme ensures that plants grouped into a
subcategory are sufficiently similar to provide a basis for
reasonable comparison of like plants. Such a subcategorization
scheme allows for the uniform application of effluent limitations
guidelines and standards to similar plants.
SELECTED SUBCATEGORIES
Based on the findings detailed in this section and supported by
the discussions in Sections III, V, and VII, the metal molding
and casting category has been divided into five subcategories.
Each subcategory has been further divided into distinct
manufacturing or air pollution control process segments that
generate unique wastewater streams. The subcategories and
process segments established for the development of effluent
limitations guidelines and standards of performance are:
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METAL HOLDING AND CASTING CATEGORY
A. Aluminum Casting Subcategory
1. Casting Cleaning
2. Casting Quench
3. Die Casting
4. Dust Collection Scrubber
5. Grinding Scrubber
6. Investment Casting
7. Melting Furnace Scrubber
8. Mold Cooling
B. Copper Casting Subcategory
1. Casting Quench
2. Direct Chill Casting
3. Dust Collection Scrubber
4. Grinding Scrubber
5, Investment Casting
6. Melting Furnace Scrubber
7. Mold Cooling
C. Ferrous Casting Subcategory
1. Casting Cleaning
2. Casting Quench
3. Dust Collection Scrubber
4. Grinding Scrubber
5. Investment Casting
6, Melting Furnace Scrubber
7. Mold Cooling
8. Slag Quench
9. Wet Sand Reclamation
D. Magnesium Casting Subcategory
1. Casting Quench
2. Dust Collection Scrubber
3. Grinding Scrubber
E. Zinc Casting Subcategory
1. Casting Quench
2. Die Casting
3. Melting Furnace Scrubber
4. Mold Cooling
The above subcategorization scheme differs somewhat from the
scheme developed for the proposed rule. The revised scheme is
identical to the one described in the Federal Register notice
dated February 15, 1985 (50 FR 6572).
At proposal, a lead casting subcategory was considered. However,
as deta1"1"-* in the March 20, 1984 Notice of Availability (49 FR
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10260)/ the lead casting subcategory was transferred for
consideration in connection with the battery manufacturing
regulation because all of the data available to the Agency on
lead casting concerns those operations and practices employed in
battery manufacturing.
All other changes in the subcategorization scheme involve
revisions to the segments listed under each subcategory. As
discussed in the March 1964 Notice of Availability (49 PR 10280}»
the Agency received comments which asserted that some operations,
which are normally a part of metal molding and casting
operations, were not covered by the proposed regulations. In
response to these comments, and to provide regulations covering
those process wastewater sources typically found at metal molding
and casting plantsr the Agency identified additional processes
not covered in the proposed subcategorization scheme which are
found at many metal molding and casting facilities. Changes in
the process segments under each subcategory are detailed below.
Aluminum Casting Subcategory - Die lube operations were combined
with die casting operations because those integrated operations
cannot be meaningfully separated. Four new process segments were
identified and added: {!) dust collection scrubber/ (2) mold
cooling, (3) grinding scrubber, and (4) casting cleaning.
Copper Casting Subcategory - The mold cooling and casting quench
process segment was divided into separate parts — the mold
cooling process segment and the casting quench process segment.
Four new process segments were identified and added: (1) direct
chill casting, (2) investment casting, (3) grinding scrubber, and
(4) melting furnace scrubber.
Ferrous Casting Subcategory - The mold cooling and casting quench
process segment was divided into separate parts — the mold
cooling process segment and the casting quench process segment,
Three additional ferrous casting segments were identified and
added: {1} investment casting, (2) casting cleaning, and (3)
grinding scrubber. In addition, the process segment originally
designated as sand washing has been redesignated as wet sand
reclamation, to represent more accurately the wastewater sources
covered by that segment.
Magnesium Casting Subcategory - One additional process segment
was identified and added: {1} casting quench.
Zinc Casting Subcategory - The die casting and casting quench
process segment were divided into separate parts — the die
casting process segment and the casting quench process segment.
One additional process segment was identified and added: (1) mold
cooling.
The Agency reviewed available data for process water sources not
previously identified in the proposed regulation. Several
processes not listed above are employed in the metal molding and
casting industry; however, their use is not sufficiently
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widespread to allow the Agency to characterize properly these
miscellaneous wastestreams. Thus, EPA is unable to establish
nationally-applicable effluent limitations guidelines and
standards for process segments other than those listed above.
Permit writers and municipal authorities will use their best
professional judgement in establishing technology-based effluent
limitations and standards for those miscellaneous streams not
covered by the final metal molding and casting industry
regulations.
SUBCATEGORY AND PROCESS SEGMENT DEFINITIONS
Metal molding and casting is defined as the remelting of a metal
or metal alloy to form an intermediate or final cast product by
pouring or forcing the molten metal into a mold. The casting of
ingots, pigs, or other cast shapes following primary metal
smelting is not included in the metal molding and casting
category; it is regulated by the nonferrous metals manufacturing
guidelines (40 CFR Part 421). The casting of aluminum or zinc
performed as an integral part of aluminum or zinc forming, and
conducted on-site at an aluminum or zinc forming plant, is
covered by the respective metal forming regulation (40 CPR Part
467 for Aluminum, Part 471 for Zinc). The metal molding and
casting category includes the aluminum, copper, ferrous,
magnesium, and zinc casting subcategories. A production process
is considered to be in a particular metal subcategory if the
molten metal contains, on average, greater than 50 percent by
weight of that metal, or if the metal comprises the greatest
percentage of the metal, measured by weight. The casting of
copper-beryllium alloys where beryllium is present at 0.1 or
greater percent by weight and the casting of copper-precious
metal alloys in which the precious metal is present at 30 or
greater, percent by weight are excluded from regulation in the
metal molding and casting category. In the following sections,
the sources of process wastewaters regulated under each
manufacturing process segment are defined. The process segments
themselves have been described in Section III of this document.
Aluminum Casting Subcateggry
1. Casting Cleaning Wastewater - Wastewater that originates
from the application of water to a cast product (casting) to
rid it of impurities such as die lubricants or sand.
Casting cleaning wastewater does not include wastewater that
originates from the rinsing of castings produced by
investment casting processes; that wastewater is regulated
under investment casting.
2. Casting Quench Wastewater - Wastewater that originates from
the immersion of a hot casting in a water bath to cool the
casting rapidly, or to change the metallurgical properties
of the casting.
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3. Die Casting Wastewater - Die casting wastewater includes two
types of wastewater discharges: leakage of hydraulic fluid
from hydraulic systems associated with die casting
operations, and the discharge of die lubricants. Any
process water used for the cooling of dies or castings still
contained in dies is not considered die casting wastewaterj
rather, it is mold cooling wastewater.
4. Dust Collection Scrubber Wastewater - Wastewater that
originates from the removal of dust from air in a scrubber,
when water or process wastewater is used as a cleaning
medium. The dust may originate with sand preparation, sand
molding, core making, sand handling and transfer, the
removal of sand from the casting (including "shake-out,"
shot-blasting, and sand blasting), or other foundry floor
dust sources. Wastewater that originates from pouring
floor, pouring ladle, and transfer ladle fume scrubbing also
is included when these fumes are collected in an air duct
system common with sand dusts. Wastewater that originates
from dust collection scrubbers associated with investment
casting operations are regulated under the investment
casting process segment.
5. Grinding Scrubber Wastewater - Wastewater that originates
from the removal of grinding dust from air in a scrubber,
when water or process wastewater is used as a cleaning
medium. Grinding dust is generated during the mechanical
abrading, or preliminary grinding of castings following
removal from the mold.
6, Investment Casting Wastewater - Wastewater generated during
investment mold backup, hydroblast cleaning of investment
castings, and the collection of dust resulting from the
hydroblasting of castings and the handling of the investment
material. Operations generating investment casting
wastewaters are sometimes called lost wax, lost pattern, hot
investment, or precision casting processes.
7. Melting Furnace Scrubber Wastewater - Wastewater generated
during the removal of dust and fumes from furnace exhaust
gases in a scrubber, when water or process wastewater is
used as a cleaning medium. The dust and fumes are generated
by melting or holding furnace operations and are expelled in
the exhaust gases from these operations. Wastewater from
pouring floor, pouring ladle, and transfer ladle fume
scrubbing also is included when the fumes from those
operations are collected in an air duct system common with
the melting or holding furnace fumes.
8. Mold Cooling Wastewater - Wastewater that originates from
the direct spray cooling of a mold or die, or of the
casting, in an open mold. Water that circulates in a
noncontact cooling water system in the interior of a mold is
not considered mold cooling process wastewater unless it
leaks from the system and is commingled with other process
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waatewaters.
Cogpjer Casting Subcategory
1, Casting Quench Wastewater - Wastewater that originates from
the immersion of a hot casting in a water bath to cool the
casting rapidly, or to change the metallurgical properties
of the casting.
2. Direct Chill Casting Wastewater - Contact cooling water used
during the direct chill casting operations. The cooling
water may be sprayed directly onto the hot casting, or it
may be present as a contact cooling water bath into which
the cast product is lowered as it is cast.
3, Dust Collection Scrubber Wastewater - Wagtewater that
originates from the removal of dugt from air in a scrubber,
when water or process wastewater is used as a cleaning
medium. The dust may originate with sand preparation, sand
molding, core making, sand handling and transfer, the
removal of sand from the casting (including "shake-out,"
shot-blasting, and sand blasting), or other foundry floor
dust sources. Wastewater that originates from pouring
floor, pouring ladle, and transfer ladle fume scrubbing also
is included when these fumes are collected in an air duct
system common with sand dusts. Wastewater that originates
from dust collection scrubbers associated with investment
casting operations are regulated under the investment
casting process segment.
4. Grinding Scrubber Wastewater - Wastewater that originates
from the removal of grinding dust from air in a scrubber,
when water or process wastewater is used as a cleaning
medium. Grinding dust is generated during the mechanical
abrading, or preliminary grinding of castings following
removal from the mold.
5. Investment Casting Wastewater - Wastewater generated during
investment mold backup, hydroblast cleaning of investment
castings, and the collection of dust resulting from the
hydroblasting of castings and the handling of the investment
material. Operations generating investment casting
wastewaters are sometimes called lost wax, lost pattern, hot
investment, or precision casting processes.
6. Melting Furnace Scrubber Wastewater - Wastewater generated
during the removal of dust and fumes from furnace exhaust
gases in a scrubber, when water or process wastewater is
used as a cleaning medium. The dust and fumes are generated
by melting or holding furnace operations and are expelled in
the exhaust gases from these operations. Wastewater from
pouring floor, pouring ladle, and transfer ladle fume
scrubbing also is included when the fumes from those
operations are collected in an air duct system common with
the melting or holding furnace fumes.
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7. Mold Cooling Wastewater - Wastewater that originates from
the direct spray cooling of a mold or die, or of the
casting, in an open mold. Water that circulates in a
noncontact cooling water system in the interior of a mold is
not considered mold cooling process wastewater unless it
leaks from the system and is commingled with other process
wastewaters.
Ferrous Casting Subeategory
1. Casting Cleaning Wastewater - Wastewater that originates
from the application of water to a cast product (casting) to
rid it of impurities such as die lubricants or sand.
Casting cleaning wastewater does not include wastewater that
originates from the rinsing of castings produced by
investment casting processes; that wastewater is regulated
under investment casting.
2. Casting Quench Wastewater - Wastewater that originates from
the immersion of a hot casting in a water bath to cool the
casting rapidly/ or to change the metallurg al properties
of the casting.
3. Dust Collection Scrubber Wastewater - Wastewater that
originates from the removal of dust from air in a scrubber,
when water or process wastewater is used as a cleaning
medium. The dust may originate with sand preparation, sand
molding, core making, sand handling and transfer, the
removal of sand from the casting (including "shake-out,"
shot-blasting, and sand blasting), or other foundry floor
dust sources. Wastewater that originates from pouring
floor, pouring ladle, and transfer ladle fume scrubbing also
is included when these fumes are collected in an air duct
system common with sand dusts. Wastewater that originates
from dust collection scrubbers associated with investment
casting operations are regulated under the investment
casting process segment.
4. Grinding Scrubber Wastewater - Wastewater that originates
from the removal of grinding dust from air in a scrubber,
when water or process wastewater is used as a cleaning
medium. Grinding dust is generated during the mechanical
abrading, or preliminary grinding of castings following
removal from the mold.
5. Investment Casting Wastewater - Wastewater generated during
investment mold backup, hydroblast cleaning of investment
castings, and the collection of dust resulting from the
hydroblasting of castings and the handling of the investment
material. Operations generating investment casting
wastewaters are sometimes called lost wax, lost pattern, hot
investment, or precision casting processes.
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6. Melting Furnace Scrubber Wastewater - Wastewater generated
during the removal of dust and fumes from furnace exhaust
gases in a scrubber, when water or process wastewater is
used as a cleaning medium. The dust and fumes are generated
by melting or holding furnace operations and are expelled in
the exhaust gases from these operations. Wastewater from
pouring floor, pouring ladle, and transfer ladle fume
scrubbing also is included when the fumes from those
operations are collected in an air duct system common with
the melting or holding furnace fumes.
7. Mold Cooling Wastewater - Wastewater that originates from
the direct spray cooling of a mold or die, or of the
casting, in an open mold. Water that circulates in a
noncontact cooling water system in the interior of a mold is
not considered mold cooling process wastewater unless it
leaks from the system and is commingled with other process
wastewaters,
8, Slag Quench Wastewater - Wastewater that originates from the
cooling or sluicing of furnace slag with water or process
water.
9. Wet Sand Reclamation Wastewater - Wastewater that originates
from the reclamation of spent sand for reuse by washing it
with water.
Hagjiesium Casting Subcategory
1, Casting Quench Wastewater - Wastewater that originates from
the immersion of a hot casting in a water bath to cool the
casting rapidly, or to change the metallurgical properties
of the casting.
2. Dust Collection Scrubber Wastewater - Wastewater that
originates from the removal of dust from air in a scrubber,
when water or process wastewater is used as a cleaning
medium. The dust may originate with sand preparation, sand
molding, core making, sand handling and transfer, the
removal of sand from the casting, and other foundry floor
dust sources. Wastewater that originates from pouring
floor, pouring ladle, or transfer ladle fume scrubbing also
is included when these fumes are collected in an air duct
system common with sand dusts.
3. Grinding Scrubber Wastewater - Wastewater that originates
from the removal of grinding dust from air in a scrubber,
when water or process wastewater is used as a cleaning
medium. In the magnesium casting subcategory, these
scrubbers serve both air pollution control and fire
retardant purposes. Magnesium dust is generated during the
mechanical abrading, or preliminary grinding of the casting
following its removal from the mold.
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Zinc Casting Subcategory
1. Casting Quench Wastewater - Wastewater that originates from
the immersion of a hot casting in a water bath to cool the
casting rapidly, or to change the metallurgical properties
of the casting,
2, Die Casting Wastewater - Die casting includes two types of
wastewater discharges: leakage of hydraulic fluid from
hydraulic systems associated with die casting operations,
and the discharge of die lubricants. Any process water used
for the cooling of dies or castings still contained in dies
is not considered die casting wastewater; rather, it is mold
cooling wastewater.
3. Melting Furnace Scrubber Wastewater - Wastewater generated
during the removal of dust and fumes from furnace exhaust
gases in a scrubber, when water or process wastewater is
used as a cleaning medium. The dust and fumes are generated
by melting or holding furnace operations and are expelled in
the exhaust gases from these operations. Wastewater from
pouring floor, pouring ladle, and transfer ladle fume
scrubbing also is included when the fumes from those
operations are collected in an air duct system common with
the melting or holding furnace fumes.
4. Hold Cooling Wastewater - Wastewater that originates from
the direct spray cooling of a mold or die, or of the
casting, in an open mold. Water that circulates in a
noncontact cooling water system in the interior of a mold is
not considered mold cooling process wastewater unless it
leaks from the system and is commingled with other process
wastewaters.
SUBCATEGORIZATION BASIS
In identifying the subcategories and subcategory process segments
for the metal molding and casting point source category, the
following factors were considered;
1. Type of metal cast
2. Manufacturing process and water use
3. Air pollution sources
4. Pollutant concentrations in raw wastewater
5. Raw materials
6. Process chemicals
7. Plant size
8. Plant age
9. Geographic location
10. Central treatment
11. Make-up water quality
The type of metal cast and the manufacturing process form the
basic framework for the selected subcategories and subcategory
segments. Many of the other factors provided additional support
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for the subcategorization scheme. These other factors, including
process wastewater characteristics, helped to delineate the final
subcategories as reflected in the subcategories and subcategory
segments developed.
Rationale fgr^ Subca_t egorization - Factors Considered
In the following sections, each of the factors listed above is
evaluated on the basis of suitability for subcategorizing the
metal molding and casting category.
Type of Metal Cast
The type of metal cast forms the primary basis for
subcategorization of the metal molding and casting category. The
wastewater sampling performed as a part of this regulatory
development effort showed that the type of metal cast in a
process does affect the type and quantities of toxic metal and
toxic organic pollutants present in the wastewater from that
process. One reason for this observation is simply the
difference in the raw material used in the metal charge. Metals
and other pollutants that are present in the furnace charge will
eventually enter the process water and will influence the process
wastewater characteristics.
In addition, metals differ in physical and chemical properties
such as melting point and malleability, and these inherent
differences in raw material influence in turn the manufacturing
process employed and the process chemicals chosen. Process
wastewater characteristics are largely determined by such factors
as these.
The metallurgical properties of the metal being cast influence
which manufacturing processes may be used during manufacture of
the desired product. For example, zinc and aluminum castngs are
frequently produced by die casting techniques, while ferrous
castings are not. Results of metal molding and casting surveys
indicate that slag quenching is associated only with ferrous
casting.
The different types of metal cast require the use of different
process chemicals. For example, aluminum and zinc are more
amenable to die casting techniques, while ferrous castings are
more often produced in sand molds. The binders and chemical
additives used in sand casting are substantially different from
the process chemicals used as mold release agents in die casting.
As a result, the wastewaters generated in the aluminum and zinc
subcategories will contain different types and quantities of
toxic organic pollutants from those found in wastewaters
generated in the ferrous subcategory. Subcategorization of the
metal molding and casting industry by metal type accounts for
these differences.
In those instances where a plant casts more than one metal, the
manufacturing processes, equipment, and pollutant sources are
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usually segregated by metal type. A specific melting furnace,
for example, melts only one metal to avoid cross contamination
with another metal. Manufacturing processes are generally
designed to handle only one metal type. Many of these
manufacturing processes (die casting for example) require the use
of special process chemicals designed for very specific
applications. These circumstances provide further support for
the subcategorization of foundries by metal type,
Examination of the analytical data indicated that differences in
alloys of the same base metal were not of sufficient magnitude to
subcategorize by alloy. This is most apparent in the ferrous
casting subcategory, where variations in raw waste characteris-
tics, manufacturing processes, and process chemicals among gray
iron, malleable iron, ductile iron, and steel foundries were not
significant enough to support subcategorization by alloy.
Manufacturing Process and Water Use
Wastewater characteristics are determined by two factors: process
water usage rates and exposure of process water to sources of
contamination. Both of these factors are dependent on the
manufacturing process employed. Water usage is highly dependent
on the cooling, cleaning, or air scrubbing requirements of a
particular process application. Similarly, the types and amounts
of pollutants present in water discharged from a process are
influenced by that process. For example, suspended solids and
metals loadings are much higher in scrubber wastewaters than in a
mold cooling wastewater discharge; for a scrubber application,
the process water is being purposely applied to collect a
particulate pollutant load. Oil and grease and organic priority
pollutant loadings are much higher in die casting wastewaters
than in casting quench wastewaters. A major portion of the die
casting wastewater discharge is water used as a carrier solution
for oily die casting lubricants.
type of
casting
Finally, many manufacturing processes are unique to the ty
metal cast. For example, results of metal molding and casting
industry surveys indicate that slag quenching is associated only
with ferrous casting. Casting techniques also differ: for
example, aluminum and zinc castings are frequently produced by
die casting methods, while ferrous castings are not.
It is clear from the above examples that a subcategorization
scheme based solely on metal type will not adequately account for
differences in wastewater characteristics and wastewater flow
rateg. To account for the differences in water use and
wastewater characteristics among the different processes, the
subcategories developed on the basis of metal type were further
divided into manufacturing process segments.
A review of each of the remaining factors on the list reveals
that the type of metal cast and the manufacturing process
employed largely determine the sources of air pollution, process
wastewater characteristics, and raw materials and process
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chemicals used. Thus, subcategorization by metal type and
manufacturing process inherently considers those factors*
Air Pollution Sources
Certain manufacturing processes are characteristic sources of air
pollution. Where required, air pollution control devices have
been installed to control air emissions from various manufactur-
ing processes. The design of these devices may be either of the
"dry" or "wet" type. An example of a "dry" type control device
is a baghouse; such dry devices are discussed in Section III.
"Wet" air pollution control devices are referred to as scrubbers,
and these devices may result in the discharge of process
wastewaters. Where scrubbers are present in the metal molding
and casting industry, they have been included in the
subcategorization scheme as separate process segments.
Pollutant Concentrations in Process Wastewater
As discussed in the previous sections, wastewater characteristics
may vary with both the type of metal cast and on the
manufacturing process employed. Thus, process wastewater
characteristics were inherently considered in the decision to
subcategorize by metal type and to divide the subcategories
further by process segment.
Raw Materials
In the metal molding and casting industry, the raw material
consists of the charge to the melting furnace. This charge
consists primarily of the metal being cast. For example, the
production of a zinc casting begins with the charge of a zinc raw
material to the melting furnace. For this reason, raw material
differences are considered in a subcategorization scheme based on
the type of metal cast,
Process Chemicals
The major process chemicals used in the manufacture of castings
fall into two general classes: those associated with sand
casting, and those associated with die casting. The process
chemicals associated with sand casting techniques include sand
and core binders and related chemical additives. Several of
these process chemicals contain toxic pollutants or chemicals
which, when exposed to high metal temperatures, may decompose to
toxic pollutant materials.
Analysis of plant data indicates the use of a wide variety of
sand casting materials. At least 14 different chemical types of
sand additives are commercially available. On-site visits to
many plants indicated that more than one type of sand additive is
often used simultaneously within the plant and that changes in
the use of the various products occur periodically.
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The process chemicals associated with die casting include die
lubricants, die coatings, and quench solution additives. These
materials are used to prevent castings from adhering to the die
and to provide a casting with improved surface characteristics.
Frequently, many different products are tried until a
satisfactory lubricant or coating is found.
Because of the wide variety of process chemicals and the frequent
changes in the use of these products, the type of process
chemical used is not an adequate basis for subcategorization.
However, since the hypes of process chemicals used are related to
the manufacturing processes employed and type of metal cast, the
difference in process chemical usage was inherently considered in
the subcategorization and segmentation scheme developed.
Plant Size
Plant size can be measured by several methods: number of
employees, production, or process wastewater flow. No
identifiable relationship between any of these three size
measurements and process wastewater characteristics was found.
Additionally, process water usage requirements per pound of metal
poured or per 1000 standard cubic feet of air scrubbed were found
to be correlated but independent of plant size. For these
reasons, plant size was not considered to provide an adequate
basis for subcategorization. However, the Agency has found that
the costs of installing and operating treatment systems does not
vary proportionally to plant size. Economies of scale exist in
that larger systems are relatively less expensive than smaller
systems. For this reason, the Agency has developed model plants
for each subcategory and process segment based on different
employment size groups (i.e., based on number of production
employees). The economic impact of compliance with limitations
and standards based on various technology options was evaluated
independently for each size group. This division of the
subcategories for economic evaluation enabled the Agency to
consider adequately any differences in the financial strength of
large and small plants in the metal molding and casting category
when evaluating the economic impacts of this regulation.
Plant Age
Plants within a given subcategory may have significantly
different ages in terms of initial operating year. To remain
competitive, however, plants must be constantly modernized.
Plants may be updated by modernizing a particular component, or
by installing new components. For example, an old furnace might
be equipped with oxygen lances to increase the throughput, or
replaced entirely by a new, more efficient furnace.
Modernization of production processes and air pollution control
equipment produced analogous wastes among all plants producing a
given metal, despite the original plant start-up date.
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Similarly, wastewater treatment equipment is installed and
modified as plants become modernized. Examination of the general
plant summary tables presented in Section 22.76 of the record for
this rulemaking indicates that the installation and operation of
wastewater treatment, including high rate recycle systems, is not
correlated with plant age. As an example, several plants which
have been in operation for over 30 years have installed treatment
and recycle facilities as recently as six years ago. At other
plants, treatment and recycle facilities have been in use for
over 35 years.
The Agency has therefore concluded that plant age does not
account for any differences among plants in raw wastewater
characteristics or in ability to install treatment equipment in
order to achieve the regulations being promulgated. Thus plant
age was not selected as an appropriate basis for
subcategorization.
Geographic Location
Plants engaged in metal molding and castings are located in all
of the industrial regions of the United States. None of the
available data indicate that the location of a plant affects the
type of metal cast, the manufacturing process employed, or other
process wastewater characteristics. Therefore, geographic
location is not an appropriate basis for subcategorization.
Geographic location may affect the quality of the make-up water
available to a plant. Make-up water quality was considered as a
basis for subcategorization and is discussed below as a separate
topic.
Central Treatment
A significant portion of the plants in the metal molding and
casting industry have more than one process generating process
wastewater, and perform combined treatment of these wastewaters
in a central treatment facility. The Agency received numerous
comments which asserted that plants with central treatment would
not be capable of achieving the same recycle rates as would those
plants that treat wastewaters from single processes separately,
The Agency also received comments which asserted that high rate
recycle of wastewaters from multiple processes concentrates
dissolved solids and other constituents in raw wastewaters and
that this concentration of pollutants results in higher effluent
concentrations from lime and settle treatment than would be
expected for treatment of wastewaters from single processes.
Therefore, these commenters asserted that metal molding and
casting plants with central treatment should be assigned a
separate subcategory.
Section VII of this Development Document contains a detailed
presentation of the recycle model analysis as it pertains to
central treatment. In summary, the Agency found from the
analysis that achievable flow weighted recycle rates for combined
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treatment systems were higher than the recycle rates predicted
for single process treatment systems, rather than lower, as
asserted in comments. The recycle model analysis did indicate
that plants in the ferrous subcategory with central treatment of
melting furnace scrubber, dust collection scrubber, and slag
quench wastewaters showed marginally lower recycle rates than
those predicted for the separate processes. However, increases
in blowdown flow rates for these three processes were provided to
account for poor make-up water quality. These increases in
blowdown were sufficient to allow facilities with central
treatment to achieve the separate stream recycle rates.
Moreover, plants which recycle to their processes after central
treatment effect greater removal of pollutants and thereby
achieve sufficiently higher recycle rates, not lower as asserted
in comments, such that individual process recycle rates are
achieved or surpassed.
The Agency's treatment effectiveness analysis, also presented in
Section VII of the Development Document, is based on data from
lime and settle treatment in the metal molding and casting
industry. Almost all of the data used in the treatment
effectiveness analysis are for plants with high rate recycle and
combined treatment of wastewaters from multiple processes in
central treatment facilities. The raw wastewaters treated by
these facilities are highly concentrated and are the most
difficult wastewaters in this industry to treat. It follows
that plants that do not practice central treatment of multiple
waste streams will be able to achieve these values, as well as
plants practicing central treatment. The Agency has concluded
that these findings support the existing subcategorization, and
that further subcategorization of the metal molding and casting
industry for central treatment plants and development of separate
recycle rates and treatment effectiveness concentrations are not
warranted.
Make-up Water Quality
The Agency's recycle model analysis also was used to determine
whether make-up water quality should serve as a basis for
subcategorization. As described in detail in Section VII of this
Development Document, the Agency found that only three process
segments among the 19 analyzed were marginally sensitive to poor
make-up water quality. All of these processes are in the ferrous
subcategory — melting furnace scrubber, dust collection
scrubber, and slag quench. By allowing for increases of 1-2
percent in blowdown flow rates (decreases in recycle rates) and
therefore increased removal from recycle systems of certain
constituents that cause scaling or corrosion, the adjusted
recycle rates were achievable even with poor make-up water
quality, without expensive and sophisticated treatment.
Therefore, the existing subcategorization incorporates the
effects of make-up water quality, and further subcategorization
is not necessary.
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Summary
For regulatory purposes, the most important reasons to
subcategorize are to account for differences among plants, either
in the type and amounts of pollutants present in the wastewater,
or in water usage rates. The primary factor likely to affect
such wastewater characteristics is the type of metal cast. An
additional important factor is the type of manufacturing process
employed. This further influences the type and amount of
pollutants in the raw waste, water use rates, and thus the
appropriateness of selected treatment technologies. For these
reasons, metal type was chosen to form the basis for
subcategorization of the metal molding and casting point source
category; the subcategories were then further segmented by
process type. This subcategorization scheme implicitly considers
such factors as wastewater characteristics, process chemicals
used, and wastewaters generated by wet air pollution control
equipment.
PRODUCTION NORMALIZING PARAMETERS
To ensure equitable regulation of the category, effluent
limitations guidelines and standards have been established on a
pollutant mass discharge basis (i.e., mass of pollutant
discharged per unit of production activity). As discussed in
later sections of this document, water conservation through high
rate recycle is an important part of the model treatment
technology for this category. To ensure that good water
conservation practices are followed, the mass of pollutants in
metal molding and casting discharges have been related to a
specific unit of production to establish limitations and
standards that will control the pollutant mass discharged
proportionate to some level of production activity. The unit of
production specified in these regulations is known as a
production normalizing parameter (PNP).
of Production Norma^izirig^ Parameters
Two criteria were used in selecting the appropriate PNP for a
given, subcategory or segment: (1) maximizing the degree of
correlation between the PNP and the corresponding discharge of
pollutants and (2) ensuring that the PNP is easily measured and
feasible for use in establishing regulations.
At proposal, the Agency considered the following for use as
production normalizing parameters: tons of sand used for dust
collection scrubber operations, tons of sand washed for sand
washing operations, and tons of metal poured for all other metal
molding and casting operations. For the four segments for which
a discharge allowance was proposed, tons of metal poured was
chosen as the production normalizing parameter.
After proposal, many comments were received stating that the use
of tons of sand used or metal poured as production normalizing
parameters for air scrubbing operations was improper. The
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commenters stated that air flow through a scrubber was a more
appropriate production normalizing parameter. After
consideration of these comments, the Agency performed a
correlation analysis for wet scrubbers to test the correlation of
water use with three parameters: tons of metal poured, tons of
sand used, and air flow (in units of 1,000 standard cubic feet
per minute or 1,000 SCFH).
The correlation analysis was run on three sets of data points:
o Production (tons poured per day) vs. water use (gallons
per day, GPD),
o Sand use (tons used per day, TPD) vs. water use (GPD),
and
o Air flow (1,000 SCFM) vs. water use (gallons per minute,
GPH) .
These sets of data were for individual process wastewater
sources, as compiled from the data collection portfolios (DCPs).
Correlation coefficients were obtained for each of these sets of
data using the linear regression function based upon the least
squares method of curve fitting.
Examination of the resulting correlation coefficients reveals
that in nearly every case, air flow correlates much more closely
to water use than either metal poured or sand used for the
process segments involving wet scrubbing, A more detailed
account of the correlation analyses performed and sets of input
and output data can be found in Section 22.28 of the public
record for this rulemaking.
After considering the comments submitted by industry and the
results of the correlation analysis, the Agency decided that air
flow was a more appropriate production normalizing parameter than
sand used or metal poured for the three scrubber-based process
segments: dust collection scrubber, grinding scrubber, and
melting furnace scrubber.
Production normalizing parameters for each segment are presented
in Table IV-1. The table shows that the production normalizing
parameter for all processes is either tons of metal poured or
thousands of standard cubic feet of air with one exception:
ferrous wet sand reclamation. The production normalizing
parameter for this process is tons of sand reclaimed.
Tons of metal poured was selected as the production normalizing
parameter for metal molding and casting operations other than
scrubber operations and sand reclamation because it is a
production record commonly maintained by metal molding and
casting plants, and it can be correlated to water use
requirements and pollutant discharge loads for the processes for
which it is used as the PNP. Tons of sand reclaimed was selected
as the production normalizing parameter for the ferrous wet sand
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reclamation process segment because it is a production record
that is or can be easily recorded or calculated, and it can be
correlated to water use requirements and pollutant discharge
loads for the wet sand reclamation process segment. Air flow was
selected as the PNP for wet scrubber operations for the reasons
described above.
Several other parameters also were considered and rejected for
use as production normalizing parameters. The rationale for
eliminating each of these parameters is discussed below.
Weight of Sand
The weight of sand used in a process was originally the produc-
tion normalizing parameter for two segments: the dust collection
scrubber segments and ferrous wet sand reclamation segments. As
previously discussed, for the dust collection segments, a
correlation analysis showed that air flow through the process
scrubber correlated much more closely to water use than did the
weight of sand used in the process.
For the ferrous wet sand reclamation segment, the weight of sand
that is actually reclaimed is more highly correlated to process
water use than is the weight of sand used because process water
is generated only during the reclamation of the sand. For
example, some plants might use a great deal of sand in their
process, but reclaim little or none of it, thus using little or
no reclamation process water.
Surface Area of Casting
Surface area was considered as a possible production normalizing
parameter for those manufacturing processes involving cleaning
because pollutants enter the cleaning water through intimate
contact with the surface of the casting. However, surface area
of a casting is a variable dependent upon the shape and design of
the castings being manufactured. In some plants, such as those
which cast miscellaneous shapes, product surface area changes
frequently and is difficult to determine. Records on product
surface area are not generally kept by industry. Therefore,
surface area was not selected as a production normalizing
parameter.
Weight of Final Product
The weight of final product is readily available in production
records, but its application as a production normalizing parame-
ter has a significant drawback.
The weight of the casting in final product form may vary substan-
tially from the casting's initial weight. Casting weight is at a
maximum when the casting is first formed (i.e., immediately after
the pouring of the molten metal into the mold). At this point,
the casting has the gates, sprues, and risers attached, and the
total weight of all the castings produced per unit time closely
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equates with the total amount of metal poured during that unit of
time.
The major reduction in weight occurs after the metal molding and
casting supportive process steps (sand preparation, mold and core
making, sand washing/ etc.) have occurred. This weight reduction
is due to the removal of the gates, sprues and risers. Weight
loss can be as little as five percent or as much as 70 percent of
the initial total casting weight, depending upoi\ the type of
metal cast, the casting shape, and the volume of the gates,
sprues, and risers required in the mold.
Additional weight changes can occur when metal is removed during
the machining of the casting or, for example, when weight is
added during the electroplating or the painting of the casting.
For the reasons stated above, the weight of the final product was
not found to be a suitable production normalizing parameter.
Process Chemicals Consumed
For the reasons stated in the discussion of the factors consid-
ered for subcategorization, the variability in the amount of
process chemicals consumed diminishes its usefulness as an
appropriate production normali2ing parameter.
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TABLE IV-1
PRODUCTION NORMALIZING PARAMETERS USED TO
DEVELOP EFFLUENT LIMITATIONS
Process Segment
Aluminum
Casting Cleaning
Casting Quench
Die Casting
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Mold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Mold Cooling
Ferrous
Casting Cleaning
Casting Quench
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Mold Cooling
Slag Quench
Wet Sand Reclamation
Magnesium
Casting Quench
Dust Collection Scrubber
Grinding Scrubber
Zinc
Casting Quench
Die Casting
Melting Furnace
Mold Cooling
Production Normalizing Parameter
Mass of metal poured
Mass of metal poured
Mass of metal poured
Volume of scrubber air flow
Volume of scrubber air flow
Mass of metal poured
Volume of scrubber air flow
Mass of metal poured
Mass of metal poured
Mass of metal poured
Volume of scrubber air flow
Volume of scrubber air flow
Mass of metal poured
Volume of scrubber air flow
Mass of metal poured
Mass of metal poured
Mass of metal poured
Volume of scrubber air flow
Volume of scrubber air flow
Mass of metal poured
Volume of scrubber air flow
Mass of metal poured
Mass of metal poured
Mass of sand reclaimed
Mass of metal poured
Volume of scrubber air flow
Volume of scrubber air flow
Mass of metal poured
Mass of metal poured
Volume of scrubber air flow
Mass of metal poured
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SECTION V
WATER USE AND WASTEWATER CHARACTERISTICS
This section presents the industry survey data that characterize
metal molding and casting water use and the analytical data that
characterize the raw wastewater from the various metal molding
and casting process segments.
DATA SOURCES
Metal Molding and Cashing Industry pjrofjLlje Data Base
Metal molding and casting water usage data were obtained
primarily from data collection portfolios completed by metal
molding and casting plants in 1977. DCP's were sent to 1,269
plants which formed a representative cross-section of the metal
molding and casting industry. The information in the portfolios
has been updated, and some additional information has been added
through several data solicitation and verification efforts that
were undertaken in response to industry comments since the DCP's
were originally received. A chronological description of these
survey efforts and the development of a metal molding and casting
industry profile data base is discussed in Section III.
Sampling and Analysis Program
In addition to the survey efforts mentioned above, the Agency
also conducted an extensive program of site visits and water
sampling and analysis at metal molding and casting plants. Site
visits were conducted primarily to directly observe metal molding
and casting processing steps, process water usage and discharge
practices, and wastewater treatment and control. The sampling
and analysis program was undertaken primarily to characterize
metal molding and casting wastewater and to identify pollutants
of concern in the metal molding and casting category. During the
sampling and analysis program, special emphasis was placed on
examining and quantifying the presence of priority pollutants.
In total, EPA and its contractors collected and analyzed samples
from 46 metal molding and casting plants during three separate
sampling efforts.
Table V-47 lists the 129 priority pollutants considered In this
study. Three pollutants have subsequently been deleted from the
list of priority pollutants - #17 bis(chloromethyl)ether, #49
trichlorofluoromethane, and #50 dichlorodifluoromethane. Samples
were collected and analyzed for 128 priority pollutants and other
pollutants deemed appropriate. Because the analytical standard
for #129 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was judged to
be too hazardous to be made generally available, samples were
never analyzed for this pollutant.
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Samples collected during the sampling program included, but were
not limited to, incoming (source) water, raw process wastewater,
and untreated, partially treated, and fully treated wastewater.
Incoming Water Analysis. Incoming water samples were collected
for each sampled plant and analyzed for various pollutants.
Overall, these analyses revealed few pollutants at concentrations
above the minimum quantifiable limit of the specific analytical
method or at concentration levels significant enough to affect
the anticipated design of a waste treatment system.
Raw Waste Analysis. The analytical data base generated through
EPA's metal molding and casting sampling activities, and used to
characterize raw wastewaters is summarized in Tables V-30 through
V-46. These summary tables present six columns of data for each
process segment where raw wastewater analytical data are
available. The first column lists the pollutants detected in
wastewater from the respective segment. The second and third
columns present the number of samples that were analyzed for each
pollutant and the number of times the pollutant was detected.
The fourth column presents the range of concentrations at which
the pollutant was detected. A zero as the minimum value in the
concentration range indicates that the pollutant was reported as
present in one or more samples at less than the detection limit-
The fifth column presents the average concentration at which the
pollutant was detected.
The average concentration was calculated as the arithmetic
average of all available data. "Less than" values were averaged
as zeros. Values reported as non-detected were not included in
the average. The last column on each table presents the average
normalized waste load generated per kkg of metal poured or sand
reclaimed, or 1,000 m3 air scrubbed. These averages were
calculated by normalizing each sampling data point to the
production or air flow at the sampled process, and then averaging
the normalized data points. Concentration data reported as "less
than" values were averaged as zeros. Concentration data reported
as non-detected were not included in the average. A tabulation
of all of the analytical data contained on Tables V-30 through V-
46 is presented in Section 22.651 of the record. Sampling trip
reports containing the original data are located in Sections 8.4,
19.3, and 22.4 of the record.
Previous discussions of raw waste characteristics of metal
molding and casting wastewater have focused on the average
concentration of a pollutant within a process segment, based on a
straight average of all available analytical data. This method
does not take into account variable water usage practices at the
actual sampled plants. In response to public comments on the
validity of conclusions drawn from this approach, the Agency has
re-examined the methodology used to determine raw waste
characteristics. Based on a review of the data available, and
the actual water usage practices under which raw waatewater
samples were collected, the Agency has adjusted the procedure by
which average raw wastewater characteristics are estimated.
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The revised methodology calculates average raw wastewater
characteristics based on normalized pollutant generation rates.
Measured concentrations at sampled plants are converted to mass
generation rates (e.g., mg pollutant per kkg of metal poured)
based on the water flow rate and the production at the sampled
process. The mass generation rates at each sampled process
within a segment are then averaged to determine an average mass
generation rate. The Agency favors this method of calculating
the mass of pollutants generated because it eliminates the impact
of variability of water usage at sampled processes from the
calcula-tion of the mass of pollutants generated. Average
wastewater characteristics can then be estimated from the average
mass generation rates based on median production normalized
flows. For example, an average mass generation rate in units of
mg/kkg will yield an average concentration in units of mg/1 when
divided by the median production normalized flow in units of
1/kkg.
Effj.uent Analysj.3. Samples of the final plant effluents were
collected at many of the plants sampled. Since a number of
plants had two or more effluent discharges, samples were
sometimes collected at each effluent discharge. For those
sampled plants which did not have an effluent discharge (i.e., no
discharge of process wastewater to a surface water or to a
municipal treatment plant), samples of treated recycled
wastewater were sometimes collected.
SITE SELECTION RATIONALE AND SAMPLING HISTORY
Three separate sampling efforts have been performed to
characterize the metal molding and casting industry raw
wastewater. These sampling efforts took place in 1974, 1978, and
1983. Each effort is discussed below.
Table V-49 summarizes the plants sampled, year sampled, and the
pollutants for which analyses were performed.
1974 Sampling Effort
In 1974, the Agency visited and collected wastewater samples at
19 ferrous foundries as part of the rulemaking effort for the
Iron and Steel Point Source Category. At that time, the
foundries industry was included as a Foundries Subcategory in the
Iron and Steel Category. Thus the 18 plants from which samples
were collected at that time were large ferrous foundries.
Samples collected consisted primarily of process wastewater from
melting furnace scrubbers, dust collection scrubbers, and slag
quenching. Analyses were performed on these samples to determine
concentrations of conventional pollutant metals, phenols,
cyanide, ammonia, and some priority pollutant metals and other
metals. The following plants were sampled during this initial
effort:
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50315 53219 56771
51026 53642 56789
51115 54321 57100
51473 55122 57775
52491 55217 58589
52881 56123 59101
59212
1978 Sampling Eff pr_t
By 1977r the metal molding and casting point source category had
been established as a separate category for foundries and die
casting facilities. The metal molding and casting category
included plants that mold or cast not only iron and steel, but
also aluminum, copper, lead, magnesium, and zinc. Prior to
proposing a regulation for this category, the Agency conducted an
extensive industry study. This study included a second sampling
effort, performed in 1978. Because the first round of sampling
in 1974 was conducted exclusively at large ferrous foundries, the
second round of sampling focused on nonferrous and small ferrous
foundries.
The information contained in the DCP responses served as the
primary basis for selecting plants for site or sampling visits
during the 1978 program. The criteria used to select specific
plants included:
1. The metal cast;
2. The foundry processes that generated wastewatersj
3. The type of air pollution control devices used, i.e.,
scrubbers or dry controls such as baghouses;
4. The type of wastewater treatment equipment in place;
5. The presence of in-process control technologies that
reduced the volume of wastewater; and
6. The degree to which process wastewater was recycled or
reused
The plants selected for sampling adequately represent the full
range of manufacturing operations found in the industry, as well
as the performance of existing treatment systems. The flow rates
and pollutant loads in the wastewaters discharged from the
operations at these plants should be representative of the flow
rates and pollutant loads that would be found in wastewaters
generated by similar operations at any plant in the same
subcategory. In addition, the sampled plants have a variety of
treatment in place. Plants with no treatment were included, as
well as plants using the technologies being considered as the
basis for regulation.
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The following plants were sampled in 1978:
Aluminum Casting Ferrous gasting
04704 00001
10308* 00002
12040* 06956
17089 07170
18139* 07929
20147 15520
15654
20009
Copper Casting Magnesium Casting
04736 08146
06809
09094 Zinc Casting
19872
04622
10308*
12040*
18139*
*These plants cast both aluminum and zinc.
Generally, two separate visits were made by the EPA project
officer and the contractor to each plant selected as a sampling
site. During the first visit, an engineering site visit, sample
point locations which represented the most appropriate flow
measurement locations were identified, and any questions about
plant operations were resolved. The engineering site visit was
conducted so that the sampling team leader could become
sufficiently familiar with the plant to conduct a technically
sound sampling survey. The information collected during the
engineering site visit, together with the previously obtained
information about the plant, was organized into a detailed
sampling plan.
During the second visit to the plant, the actual sampling was
conducted. Wherever possible, samples were collected by an
automatic, time-series compositor over three consecutive 8 to 24
hour sampling and operational periods. Where automatic
compositing was not possible, grab samples were collected and
composited manually. In addition to the wastewater sampling and
flow measurement tasks performed during the sampling visits,
specific technical information was also obtained for each sampled
plant. This technical information included production and raw
material usage during the period of sampling, and routine
maintenance procedures and equipment. Also, during the sampling
visits, existing or potential problems and preventive maintenance
procedures associated with the use of high rate recycle systems
were discussed with plant personnel.
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A major goal of this study was the characterization of metal
molding and casting process wastewaters with respect to toxic
pollutants. A complete list of the toxic pollutants, as
developed from the NRDC Settlement Agreement and in the Clean
Water Act, is presented in Table V-47. Analyses were also
performed for a number of other pollutants, many of which are
introduced into process wastewater as a result of foundry
operations. These pollutants are identified on Table V-48.
Analyses for several of these pollutants, i.e., total solids,
temperature, calcium hardness, alkalinity, acidity, and pH, were
performed so that Langelier Saturation Indices could be deter-
mined for various high rate recycle systems. The Langelier
Saturation Index provided data which were used to assess the
possible scaling or corrosion problems that can be associated
with wastewater recycle systems.
Metal analyses on samples collected in 1974 were made by
inductively coupled plasma atomic emission spectrometry, except
for mercury, which was analyzed by the standard flameless atomic
adsorption method. Metals analyses on samples collected in 1978
were performed by appropriate flame and flameless atomic
adsorption methods.
Analyses for cyanide and cyanide amenable to chlorination were
performed using methods promulgated by the Agency under Section
304(h) of the Act (304(h) methods).
Analysis for asbestos fibers included transmission electron
microscopy with selected area detraction; results were reported
as chrysotile fiber count.
Analyses for conventional pollutants (BODEi, TSS, pH, and oil and
grease) and nonconventional pollutants (ammonia, fluoride,
aluminum, magnesium, and iron, etc.) were performed by 304(h)
methods.
EPA employed the analytical methods for the organic pollutants
that are described in a sampling and analytical protocol. This
protocol is set forth in Sampling and Analysis Procedures for
Screening of^ Industrial Effluents for Priority Pollutants,
revised April 1977.
Analysis for total phenols was performed using the 4-
aminoantipyrine (4-AAP) method.
1963 SampHng Effort
In response to comments on the proposed regulation, the Agency
conducted extensive site visits and some additional field
sampling in 1983. The most prevalent comment received by EPA was
that the proposed requirement for complete recycle was not
technically feasible. A number of additional comments indicated
that the Agency did not use an appropriate basis for establishing
effluent limitations for those process segments where discharges
were allowed. It was asserted that the Agency's use of the
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combined metals data base to establish limitations for the metal
molding and casting category wag not appropriate because these
data represent treatment of wastewaters from industries whose
wastewaters are not comparable to the metal molding and casting
industry. In addition, many comments received by EPA asserted
that die casting operations discharge very small quantities of
wastewater and are significantly different from foundries, and
therefore require either no regulation, or regulation as a
separate entity from foundries.
To address adequately the above comments the Agency conducted
several data gathering and verification efforts, including
conducting engineering site visits at 35 metal molding and
casting facilities. In addition, the Agency conducted field
sampling at seven of those facilities. The goals of the
additional site visits and sampling efforts were toi
1. Collect additional data on chemical addition,
sedimentation, and filtration wastewater treatment
systems at metal molding and casting plants;
2. Observe and collect additional data on wet die casting
operations; and
3. Verify the demonstration status of complete recycle/no
discharge for scrubber operations.
EPA worked closely with several industry trade associations
including American Die Casting Institute, Cast Metals Federation,
and American Foundrymen's Society to identify representative
plants to visit during these data gathering efforts. The seven
plants where field sampling was conducted are listed below:
Metal Molding and Casting Plants Sampled in 1983
Plant Subca tegory
09441 Ferrous
10837 Ferrous
15265 Aluminum
17230 Ferrous
20007 Ferrous
20017 Copper
50000 Ferrous
A complete record of the findings and results of the plant visits
and sampling is contained in plant visit reports located in
Sections 22.4 and 22.5 of the record. A summary of the sample
collection procedures and analytical methods used during the
field sampling program is presented here. Samples were generally
collected over three consecutive operating days. Operating days
varied from 8 to 24 hours in length. Automatic composite samples
were collected whenever possible. If automatic compositing
equipment could not be used, samples were collected and
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composited manually. Samples for oil and grease and phenol
analyses were collected once each day as grab samples. Samples
for volatile organic priority pollutant analysis were collected
as grab samples in 40 ml glass vials (VGA's), VGA's collected on
a single sampling day at a single sampling point were composited
at the laboratory prior to analysis. As during the sample
collection activities conducted in 1978, samples were collected
and preserved according to the protocols outlined in
and Analysis Procedures for Screening of Industrial Effluents for
Priority Pollutants, April 1977. Protocols specified in the
December 3, 1978 Federal Register, beginning at page 69559 were
also followed, as appropriate.
Samples were analyzed for priority pollutant metals (with the
exception of mercury) by Atomic Absorption Spectroscopy (AA) and
Inductively Coupled Argon Plasma Emission Spectroscopy (ICAPESJ.
The former is described in 40 CFR Part 136 and the latter can be
found in the amendments proposed in the December 5, 1979 Federal
Register, page 69559. Mercury analysis was performed by
automated cold vapor atomic absorption. Method 245.2, Methods for
Chemical Analysis of Water and Wastes, U.S. EPA, EMSL,
Cincinnati, Ohio, 1979.
Volatile organic priority pollutants were analyzed by GC/MS
Method 1624. Acid and base/neutral extractable organic priority
pollutants were analyzed by GC/MS Method 1625. In addition to
priority pollutant analysis, samples were generally analyzed for
total alkalinity, chloride, calcium hardness, pH, phenol (4-AAP),
silica, dissolved solids, suspended solids, oil (extraction —
gravimetric), sulfate ( turbimetric) , and ICAPES metals,
WATER USE AND WASTE CHARACTERISTICS
Data collection portfolios, as well as responses to data
solicitation and verification efforts conducted in response to
industry comments, were used to determine water use and waste
characteristics for each process segment in each subcategory.
Data available in the DCP's formed the bases of the metal molding
and casting water use data base. This data base was updated as
additional data were received via industry responses to data
solicitations and verification requests. The metal molding and
casting water use data base was used to determine applied flow
rates, recycle rates, and levels of treatment currently in-place.
Analytical data collected during the sampling and analysis
program were used to determine raw waste characteristics, as well
as the effectiveness of lime and settle treatment technology (the
latter is discussed in Section VII).
This subsection discusses the quantity of raw wastewater
generated in each subcategory and the quantity of that wastewater
that is discharged to navigable waters (direct discharge) and to
POTW s (indirect discharge). For each process segment, the
quantity of raw wastewater generated, the quantity discharged
directly and indirectly, the range of reported recycle rates, the
range of applied flow rates, and the treatment currently in-place
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is discussed. Finally, a summary of the raw wastewater sampling
that was performed is presented for each process segment.
Sampling was performed at 17 of the 31 process segments. In
process segments where no sampling data are available, the
transfer of data from similar segments is discussed.
Tables V-l through V-29 at the end of this section summarize the
applied flow rates reported for each process segment. These flow
rates are used in Section IX to select a BPT applied flow rate.
Tables V-30 through V-46 at the end of this section summarize the
raw wastewater sampling data for each process segment. Figures
V-l through V-46 at the end of this section are process flow
schematics which show the location of sampling points at each
sampled facility.
Aluminum Subcategory
An estimated 2.41 billion gallons of raw process wastewater are
generated each year by discharging facilities in the aluminum
subcategory. Sixty percent of this wastewater is generated by
facilities discharging to navigable waters, and 40 percent is
generated by facilities discharging to POTW's. Plants in the
aluminum subcategory account for approximately 3 percent of the
raw wastewater generated by plants in the metal molding and
casting industry.
Casting Cleaning
Casting cleaning wastewater originates from the application of
water to a cast product (casting) to rid it of impurities such as
die lubricants or sand. Casting cleaning wastewater does not
include wastewater that originates from the rinsing of castings
produced by investment casting processes; that wastewater is
regulated under investment casting.
An estimated 69.4 million gallons of process wastewater are
generated each year by aluminum casting cleaning processes that
discharge wastewaters. This represents 2.9 percent of the total
raw process wastewater generated by discharging facilities within
the aluminum subcategory. Ninety-four percent of aluminum
casting cleaning wastewater discharged is discharged to navigable
waters, while 6 percent is discharged to POTW's. One plant with
this process segment practices recycle and supplied sufficient
information to calculate a recycle rate. This plant reported 100
percent recycle. The applied flow rates for this process segment
are summarized in Table V-l, and range from 183 gallons/ton to
14,270 gallons/ton.
Two of three facilities with this process segment report having
wastewater treatment currently in-place. One plant (plant
#12040) has emulsion breaking, gas flotation, lime addition,
polymer flocculation, and vacuum filtration. The other plant
(plant #74992) has a settling basin with polymer flocculation,
and a thickener.
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Raw waatewater sampling data that characterize aluminum casting
cleaning process wastewater are not available. All data used to
characterize the aluminum casting cleaning raw wastewater have
been transferred from the ferrous casting cleaning process
segment. Both of those process segments process a non-toxic
metal (i.e., aluminum or iron) using similar processing steps.
Wastewaters from both' segments should contain similar levels of
toxic metals, organics, conventional and nonconventional
pollutants.
Casting Quench
A general process and water flow diagram of a representative
aluminum casting quench operation is presented in Figure III-3,
The process wastewaters considered in association with this
operation are those wastewaters which are discharged from the
casting quench tanks.
An estimated 132 million gallons of process wastewater are
generated each year by aluminum casting quench processes that
discharge wastewater. This represents 5.5 percent of the total
raw process wastewater generated by discharging facilities with
the aluminum subcategory. Fifty-eight percent of aluminum
casting quench wastewater discharged is discharged to navigable
waters, while 42 percent is discharged to POTW's. Fourteen
plants with this process segment practice recycle and supplied
sufficient information to calculate a recycle rate. These
recycle rates ranged from 73 percent to 100 percent. The applied
flow rates for this process segment are summarized in Table V-2,
and range from 1.45 gallons/ton to 6,866 gallons/ton.
Nine of 33 facilities with this process segment report having
wastewater treatment currently in-place. Three plants report
settling lagoons, five plants report oil skimming, three plants
report flocculation using either polymer, alum or lime, one plant
reports neutralization using acid and caustic, and one plant
reports using activated sludge, a deep sand bed pressure filter,
and granular activated carbon.
Raw wastewater sampling was performed at two facilities to
characterize aluminum casting quench process wastewater. This
raw wastewater data is summarized in Table V-30. Casting quench
wastewater contains toxic organic and metal pollutants, oil and
grease, and suspended solids.
Plant 10308, Figure V-13, generates zinc casting quench wastes,
aluminum casting quench wastes {sample point C), cutting and
machining coolant wastes, and impregnating wastes which are co-
treated in a batch-type system. After undergoing chemical
emulsion breaking using sulfuric acid and alum, neutralization,
flocculation and solids separation/ the treated effluent is
discharged to a landlocked swamp.
Plant 18139, Figure V-21, has a number of casting machines and
associated quench tanks ™Mch are emptied on a scheduled basis.
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The schedule results in the emptying of one 1,135.5 liter (300
gallon) quench tank each operational day. Each quench tank is
emptied approximately once a month {aluminum casting quench is
sample point E). The quench tank discharge mixes with melting
furnace scrubber discharges, zinc casting quench tank flows, and
other non-foundry flows prior to settling and skimming. The
treated process wastewaters are discharged to a POTW.
Die Casting
A general process and water flow diagram of a representative
aluminum die casting operation is depicted in Figure III-3.
Sources of die casting wastewaters include leakage of hydraulic
fluid from hydraulic systems associated with die casting
operations and discharge of die lube solutions that are applied
to the die surface prior to casting. Die lube solutions are
emulsions that contain casting release agents which permit the
casting to fall away or be readily removed from the dies. Any
process water used for the cooling of dies or castings still
contained in dies is not considered die casting wastewater;
rather, it is mold cooling wastewater.
An estimated 56 million gallons of process wastewater are
generated each year by aluminum die casting processes that
discharge wastewater. This represents 2.3 percent of the total
raw process wastewater generated by discharging facilities within
the aluminum subcategory. Twenty-three (23) percent of aluminum
die casting wastewater discharged is discharged to navigable
waters, while 77 percent is discharged to POTW's. Nine plants
with this process segment practice recycle and supplied suffi-
cient information to calculate a recycle rate. These recycle
rates ranged from 20 percent to 100 percent. The applied flow
rates for this process segment are summarized in Table V-3» and
range from 2.1 gallons/ton to 600 gallons/ton.
Twenty of 41 facilities with this process segment report having
wastewater treatment currently in-place. Ten plants have
settling basins, 14 have oil skimming, one plant has emulsion
breaking, six plants have lime precipitation, polymer addition
and settling, five plants have either pressure or deep sand
filters, and three plants have biological treatment.
Raw wastewater sampling was performed at four facilities to
characterize aluminum die casting process wastewater. This raw
wastewater data is summarized in Table V-31. Die casting
wastewater contains toxic organic and metal pollutants, phenols,
emulsified and free oil, and suspended solids.
Plant 12040, Figure V-15, produces aluminum (sample point B) and
zinc die casting process wastewaters which are co-treated. After
collection in a receiving tank where oil is skimmed, they are
batch treated by emulsion breaking, flocculation and settling
before discharge. The released oil is returned to the receiving
tank for skimming, and the settled wastes are vacuum filtered and
dried before being landfilled. Filtrate water is returned to the
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receiving tank.
Plant 15265, Figure V-16, has an aluminum die casting operation.
Wastewater from this operation, sample point C, is commingled
with impregnation system water and miscellaneous foundry process
water prior to treatment. Treatment consists of oil removal,
activated sludge, lime and polymer addition, clarification, and
sand filtration.
Plant 17089, Figure V-19, produces die casting and casting quench
wastes (sample point C) which are skimmed of oil and then co-
treated with melting furnace scrubber wastewaters. The treatment
consists of alum and polymer additions in a flash mix tank
followed by clarification, pressure filtration, recycle, and
discharge. Clarifier underflow is thickened and dewatered in a
centrifuge before being dried in a basin. Sixty-five percent of
the treated water is reused in the plant, and the remainder is
discharged.
Plant 20147, Figure V-26, indicated that the sources of die
casting process wastewaters are: (1) excess die lube sprayed on
the dies for additional cooling, (2) leakage from die cooling
(noncontact cooling water which becomes mixed with process
wastewater), (3) leakage from hydraulic system cooling water
(noncontact cooling water which passes through a heat exchanger
to cool the hydraulic oil and become mixed with process
wastewater), and (4) hydraulic oil leakage. Process wastewater
is controlled in three ways. On each shift, maintenance
personnel inspect each die casting machine for leaks. Where
necessary, repairs are made during the shift to reduce the
process wastewater flow. Under the die of each machine, a pan
collects excess die lube which drips from the die. A portable
pump and tank is wheeled to each machine during each shift to
collect the die lube collected in the pans. In addition, on the
floor around each die casting machine, a dam contains the process
wastewater from various leaks. Die lubricant which does not
collect in the pan is also contained by the dam. The process
wastewater collected in this manner flows to storage tanks
through a floor drain (sample point C).
Stratification of the process wastewater into three layers occurs
in the storage tanks. Tramp oil floats to the top and is removed
by a belt collector. The tramp oil is collected, stored, and
removed by a contractor. The middle layer, comprised of die
lubricant, is removed to a second tank. From this second tank,
the die lubricant passes through a cyclonic filter. The die
lubricant removed through the top of the cyclone passes through a
paper filter and then is stored, until it is reused on the die
casting machines. The material removed from the bottom of the
cyclone is stored, until it is removed by a contract hauler.
Die lubricants collected in the pans beneath the dies (sample
point G) are removed to the reconstruction area of the plant,
where the used die lubricant passes through a paper filter, is
mixed with new lubricant and water to bring it up to
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specification, and is stored until needed on the die casting
machines.
Dust Collection Scrubber
Dust collection scrubber wastewater originates in the removal of
dust from air in a scrubber, when water or process wastewater is
used as a cleaning medium. The dust may originate with sand
preparation, sand molding, core making, sand handling and
transfer, the removal of sand from the casting (including shake-
out and shot-blasting), or other dust sources on the foundry
floor. Wastewater that originates from pouring floor, pouring
ladle, and transfer ladle fume scrubbing also is included when
these fumes are collected in an air duct system common with sand
dusts. Wastewater that originates from core and mold making fume
scrubbing is also included in dust collection scrubbing, except
when such fumes are cleaned in a separate scrubbing device
dedicated to the core and mold making fumes, and the resulting
wastewater is then contract hauled or sent to a reclaimer,
Wastewater that originates from dust collection scrubbers
associated with investment casting operations are regulated under
the investment casting process segment.
An estimated 59.4 million gallons of process wastewater are
generated each year by aluminum dust collection scrubber
processes that discharge wastewater. This represents 2,5 percent
of the total raw process wastewater generated by discharging
facilities within the aluminum subcategory. Fifty-five percent
of aluminum dust collection scrubber wastewater discharged is
discharged to navigable waters, while 45 percent is discharged to
POTW's. Three plants with this process segment practice recycle
and supplied sufficient information to calculate a recycle rate.
These recycle rates ranged from 75 percent to 99 percent. The
applied flow rates for this process segment are summarized in
Table V-4, and range from 0.03 gallons/1,000 scf to 10.4
gallons/1,000 scf.
Two of 14 facilities with this process segment report having
wastewater treatment currently in-place. One plant (#00206)
reported a settling lagoon, and another plant (#74992) reported a
settling basin.
Raw wastewater sampling data that characterize aluminum dust
collection scrubber wastewater are not available. All data used
to characterize aluminum dust collection scrubber wastewater have
been transferred from the aluminum melting furnace scrubber
segment. Both of these segments generate wastewaters from the
wet scrubbing of dusts and fumes related to aluminum metal
molding and casting operations. Pouring floor and pouring ladle
fumes can either be routed to a melting furnace scrubber or a
dust collection scrubber depending on a plant's actual duct
configuration. Because both melting furnace scrubbers and dust
collection scrubbers are employed on air flows with similar
characteristics, wastewaters from both segments should contain
similar levels of toxic metals, organics, conventional, and
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nonconventional pollutants.
Grinding Scrubber
Grinding scrubber wastewater originates from the removal of
grinding dust from air in a scrubber, when water or process
wastewater is used as a cleaning medium. Grinding dust is
generated during the mechanical abrading/ or preliminary grinding
of castings following removal from the mold.
An estimated 0.89 million gallons of process wastewater are
generated each year by aluminum grinding scrubber processes that
discharge wastewater. This represents 0.04 percent of the total
raw process wastewater generated by discharging facilities within
the aluminum subcategory. Twenty-six percent of aluminum
grinding scrubber wastewater discharged is discharged to
navigable waters, while 74 percent is discharged to POTW's. No
plant with this process segment practices recycle and supplied
sufficient information to calculate a recycle rate. The applied
flow rates for this process segment are summarized in Table V-5,
and range from 0.033 gallons/1,000 scf to 1.75 gallons/1,000 scf.
One of three facilities with this process segment reported having
wastewater treatment currently in-place. This plant (#04704) has
alkali addition, polymer flocculation, lamella plate settling,
and filtration.
Raw wastewater sampling data that characterize aluminum grinding
scrubber wastewater are not available. All data used to
characterize aluminum grinding scrubber wastewater have been
transferred from the magnesium grinding scrubber segment. Both
of these segments generate wastewater from the wet scrubbing of
grinding dusts generated by processing a non-toxic metal {i.e.,
aluminum and magnesium) casting, using similar technology and
equipment. Therefore, wastewaters from both segments should
contain similar levels of toxic metals, organics, conventional,
and nonconventional pollutants.
Investment Casting
A general process and water flow diagram of a representative
aluminum investment casting operation is presented in Figure III-
2. The process wastewater in this operation results from several
processes. The processes are mold backup, hydroblast (of
castings), and dust collection (used in conjunction with
hydroblasting and the handling of the investment material and
castings).
An estimated 79.2 million gallons of process wastewater are
generated each year by aluminum investment casting processes that
discharge wastewater. This represents 3,3 percent of the total
raw process wastewater generated by discharging facilities within
the aluminum subcategory. Ninety-one percent of aluminum
investment casting wastewater discharged is discharged to
navigable waters, while 9 percent is discharged to POTW's, No
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plant with this process segment practices recycle and supplied
sufficient information to calculate a recycle rate. The applied
flow rates for this process segment are summarized in Table V-6,
and range from 3,000 gallons/ton to 68,550 gallons/ ton. As
discussed in Section IX, aluminum, copper, and ferrous investment
casting applied flow rates are considered together because half
of the investment casting plants surveyed cast all three metals
using the same or similar equipment.
All three facilities with this process segment report having
wastewater treatment currently in-place. One plant (#04704) has
polymer flocculation, Lamella plate settling, and paper
filtration. Another plant (#05206) has a settling basin. The
third plant (#20063) has a settling lagoon.
Raw wastewater sampling was performed at one facility to
characterize investment casting process wastewater. This raw
wastewater data is summarized in Table V-32. These data show
treatable concentrations of toxic organic and metal pollutants,
oil and grease, and suspended solids.
Plant 04704, Figure V-4, generates process wastewaters from mold
back-up, hydroblast casting cleaning, and dust collection, which
are co-treated (sample points B, D and E, respectively). Polymer
is added to aid settling in a Lamella plate separator. The
Lamella sludge is filtered through a paper filter, with the
filtrate being returned to the headworks of the treatment system.
The treated effluent is discharged to a river.
Melting Furnace Scrubber
A general process and water flow diagram of a representative
aluminum melting furnace operation and its scrubber system is
presented in Figure III-2. The quality and cleanliness of the
material charged in the furnace influences the emissions from the
furnace. Generally, aluminum furnaces which melt high quality
material do not require "wet" air pollution control devices
(i.e., afterburners may be used for air pollution control).
However, when dirty, oily scrap is charged, the furnace emissions
are often controlled through the use of scrubbers. The process
wastewater from these scrubbers may be either recirculated within
the scrubber equipment package (which includes a settling
chamber) or discharged to an external treatment system and then
recycled back to the scrubber.
An estimated 1,148 million gallons of process wastewater are
generated each year by aluminum melting furnace scrubber
processes that discharge wastewater. This represents 47.7
percent of the total raw process wastewater generated by
discharging facilities within the aluminum subcategory. Eighty-
one percent of aluminum melting furnace scrubber wastewater
discharged is discharged to navigable waters, while 19 percent is
discharged to POTW's. Six plants with this process segment
practice recycle and supplied sufficient information to calculate
a recycle rate. These recycle rates ranged from 37 percent to 98
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percent. The applied flow rates for this process segment are
summarized in Table V-7, and range from 0.43 gallons/1,000 scf to
12 gallons/ 1,000 scf.
Three of seven facilities with this process segment report having
wastewater treatment currently in-place. Plant #13562 employs
oil skimming and settling. Plant #17089 employs oil skimming,
settling, polymer addition, pressure filtration and activated
carbon adsorption. Plant #20114 employs acid neutralization and
settling in a holding tank.
Raw wastewater sampling was performed at two facilities to
characterize aluminum melting furnace scrubber process
wastewater. This raw wastewater data is summarized in Table V-
33. That data shows treatable concentrations of toxic metal and
organic pollutants, phenols, oil and grease, and suspended
solids.
Plant 17089, Figure V-19, produces die casting and casting quench
process wastewaters which are skimmed of oil and then co-treated
with melting furnace scrubber process wastewaters (melting
furnace scrubber water is sample point E). At the time of
sampling, the treatment consisted of alum and polymer additions
in a flash mix tank followed by clarification, pressure
filtration, recycle, and discharge. The clarifier underflow was
thickened and dewatered in a centrifuge before being dried in a
basin. Sixty-five percent of the treated process wastewater was
reused in the plant, while the remainder was discharged to
navigable waters. Since the completion of the sampling visit,
this plant has added an activated carbon adsorption system.
Plant 18139, Figure V-21, generates process wastewater from a
Venturi scrubber on the aluminum melting furnaces {sample point
C). The process wastewater is recirculated through a settling
tank. Overflow from the setting tank is mixed with process
wastewaters from the zinc melting furnace and aluminum and zinc
casting quenches. The mixed process wastewater passes through a
settling basin, an oil separator and storage tanks before
discharge.
Mold Cooling
Mold cooling wastewater originates from the direct spray cooling
of a mold or die, or of the casting, in an open mold. Water that
circulates in a noncontact cooling water system in the interior
of a mold is not considered mold cooling process wastewater
unless it leaks from the system and is commingled with other
process wastewaters.
An estimated 861 million gallons of process wastewater are
generated each year by aluminum mold cooling processes that
discharge wastewater. This represents 35.8 percent of the total
raw process wastewater generated by discharging facilities within
the aluminum subcategory. Thirty percent of aluminum mold
cooling wastewater discharged is discharged to navigable waters,
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while 70 percent is discharged to POTW's. Seven plants with this
process segment practice recycle and supplied sufficient
information to calculate a recycle rate. These recycle rates
ranged from 37 percent to 99.9 percent. The applied flow rates
for this process segment are summarized in Table V-8, and range
from 103.2 gallons/ton to 202f300 gallons/ton.
Five of 17 facilities with this process segment report having
wastewater treatment currently in-place. Two plants have
emulsion breaking, four plants have oil removal, one plant has
lime precipitation/ and one plant only has a settling lagoon.
Raw wastewater sampling data that characterize aluminum mold
cooling wastewater are not available. All data used to
characterize aluminum mold cooling wastewater have been
transferred from the aluminum casting quench segment. Both of
these segments generate wastewater from the contact cooling of
metallic mold or casting surfaces. Data available for the
ferrous subcategory indicate that mold cooling and casting quench
wastewater have similar characteristics. Therefore, wastewaters
from the aluminum casting quench and mold cooling segments should
contain similar levels of toxic metals, organics, conventional,
and nonconventional pollutants.
Copper Subcategory
An estimated 12.01 billion gallons of raw process wastewater are
generated each year by discharging facilities in the copper
subcategory. Eighty-five percent of this wastewater is generated
by facilities discharging to navigable waters, and 15 percent is
generated by facilities discharging to POTW's. Plants in the
copper subcategory account for approximately 14 percent of the
raw wastewater generated by plants in the metal molding and
casting industry.
Casting Quench
Casting quench wastewater originates in the immersion of a hot
casting in a water bath to rapidly cool the casting, or to change
the metallurgical properties of the casting.
An estimated 823 million gallons of process wastewater are
generated each year fay copper casting quench processes that
discharge wastewater. This represents 6.9 percent of the total
raw process wastewater generated by discharging facilities within
the copper subcategory. Fifty-eight (58) percent of copper
casting quench wastewater discharged is discharged to navigable
waters, while 42 percent is discharged to POTW's. Seven plants
with this process segment practice recycle and supplied
sufficient information to calculate a recycle rate. These
recycle rates ranged from 92 percent to 100 percent. The applied
flow rates for this process segment are summarized in Table V-9,
and range from 8.93 gallons/ton to 26f470 gallons/ton.
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Twelve of 21 facilities with this process segment report having
wastewater treatment currently in-place. Five plants have
cooling towers, two plants have oil skimming, three plants have
chemical addition, and five plants have settling basins or
lagoons.
Raw wastewater sampling data that characterize copper casting
quench wastewater are not available. All data used to
characterize copper casting quench wastewater have been
transferred from the copper mold cooling segment. Both of these
segments generate wastewater from the contact cooling of metallic
mold or casting surfaces. Data available for the ferrous
subcategory indicate that mold cooling and casting quench
wastewater have similar characteristics. Therefore, wastewaters
from the copper casting quench and mold cooling segments should
contain similar levels of toxic metals, organics, conventional,
and nonconventional pollutants.
Direct Chill Casting
Direct chill casting wastewater is contact cooling water used
during the direct chill casting operation. The cooling water may
be sprayed directly onto the hot casting, or it may be present as
a contact cooling water bath into which the cast product is
lowered as it is cast.
An estimated 7,427 million gallons of process wastewater are
generated each year by copper direct chill casting processes that
discharge wastewater. This represents 61.8 percent of the total
raw process wastewater generated by discharging facilities within
the copper subcategory. One hundred percent of copper direct
chill casting wastewater discharged is discharged to navigable
waters, while none is discharged to POTW's. Seven plants with
this process segment practice recycle and supplied sufficient
information to calculate a recycle rate. These recycle rates
ranged from 92 percent to 99 percent. The applied flow rates for
this process segment are summarized in Table V-10, and range from
2,858 gallons/ton to 9,617 gallons/ton.
Six of seven facilities with this process segment report having
wastewater treatment currently in-place. One plant has a cooling
tower, one plant has oil skimming, two plants have equalization
{one of these two has chromium reduction), three plants have
chemical addition, and three plants have settling devices.
Raw wastewater sampling was performed at one facility to
characterize copper direct chill casting process wastewater.
This raw wastewater data is summarized in Table V-34. Direct
chill casting water contains toxic metal pollutants, oil and
grease, and suspended solids.
Plant 20017, Figure V-25, operates several direct chill casting
units. Three of these units (numbers 2, 3 and 5) discharge into
the east hot well. Samples were taken of the water in this hot
well (sample point C). From this hot well, most of the water is
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recirculated to the casting operation through a cooling tower,
while a portion is bled-off to treatment. Treatment consists of
lime and polymer addition, followed by clarification.
Dust Collection Scrubber
A general process and water flow diagram of a typical copper dust
collection scrubber system is presented in Figure III-4. Dust
collection scrubber wastewater originates in the removal of dust
from air in a scrubber, when water or process wastewater is used
as a cleaning medium. The dust may originate with sand
preparation, sand molding, core making, sand handling and
transfer, the removal of sand from the casting (including shake-
out and shot-blasting), or other dust sources on the foundry
floor. Wastewater that originates from pouring floor, pouring
ladle, and transfer ladle fume scrubbing also is included when
these fumes are collected in an air duct system common with sand
dusts. Wastewater that originates from core and mold making fume
scrubbing is also included in dust collection scrubbing, except
when such fumes are cleaned in a separate scrubbing device
dedicated to the core and mold making fumes, and the resulting
wastewater is then contract hauled or sent to a reclaimer.
Wastewater that originates from dust collection scrubbers
associated with investment casting operations are regulated under
the investment casting process segment.
An estimated 289 million gallons of process wastewater are
generated each year by copper dust collection scrubber processes
that discharge wastewater. This represents 2.4 percent of the
total raw process wastewater generated by discharging facilities
within the copper subcategory. Eighty-two (82) percent of copper
dust collection scrubber wastewater discharged is discharged to
navigable waters, while 18 percent is discharged to POTW's.
Seven plants with this process segment practice recycle and
supplied sufficient information to calculate a recycle rate. The
recycle rates ranged from 97 percent to 100 percent. The applied
flow rates for this process segment are summarized in Table V-ll,
and range from 0.03 gallons/1,000 scf to 11 gallons/1,000 scf.
Five of 13 facilities with this process segment report having
wastewater treatment currently in-place. Treatment consists of
primary settling using either a settling basin or settling
lagoon,
Raw wastewater sampling was performed at two facilities to
characterize copper dust collection scrubber process wastewater.
This raw wastewater data is summarized in Table V-35. Dust
collection scrubber water contains toxic metal and organic
pollutants, oil and grease, phenols, and suspended solids.
Plant 09094, Figure V-ll, produces process wastewater from three
internal recycle dust collectors (only two scrubbers were sampled
- sample points D and E). The process wastewaters are collected
and treated in a series of three lagoons to provide solids
removal. The lagoon effluent is recycled back to the scrubbers.
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Discharge from the ponds was eliminated in 1977 when the ponds
were dammed. Additional water from the lagoons is used to sluice
the sludge from the settling chambers of the three scrubbers to
the first pond.
Plant 19872, Figure V-22, uses a dust collector scrubber with an
internal recycle rate of 100 percent. Samples of scrubber liquor
(sample point B) were taken from this recycle loop. Settled
sludge is removed by a dragout mechanism for disposal.
Grinding Scrubber
Grinding scrubber wastewater originates from the removal of
grinding dust from air in a scrubber, when water or process
wastewater is used as a cleaning medium. Grinding dust is
generated during the mechanical abrading, or preliminary grinding
of castings following removal from the mold.
An estimated 2.6 million gallons of process wastewater are
generated each year by copper grinding scrubber processes that
discharge wastewater. This represents 0.02 percent of the total
raw process wastewater generated by discharging facilities within
the copper subcategory. None of this wastewater quantity is
discharged to navigable waters, while 100 percent of copper
grinding scrubber wastewater discharged is discharged to POTWs,
Two plants with this process segment practice recycle and
supplied sufficient information to calculate a recycle rate.
These two plants reported recycle rates of 100 percent. The
applied flow rates for this process segment are summarized in
Table V-12. Only one plant reported sufficient information to
calculate an applied flow rate. Plant 104851 reported an applied
flow of 0.111 gallons/1,000 scf.
Three of six facilities with this process segment report having
wastewater treatment currently in-place. Two plants employ
primary settling using a settling lagoon and one plant employs
caustic addition.
Raw wastewater sampling data that characterize copper grinding
scrubber wastewater are not available. All data used to
characterize copper grinding scrubber wastewater have been
transferred from the copper direct chill casting segment. This
data transfer is appropriate because both operations produce
similar effects on the outer surface of the workpiece: direct
chill casting flashes off the skin from a hot ingot, and grinding
scrubber wastewater is generated by a process where that same
surface is physically abraded off. In both cases, the outer
surface of the workpiece becomes the major pollutant load
introduced into the wastewater. Therefore, wastewaters from both
segments should contain similar levels of toxic metals, organics,
conventional, and nonconventional pollutants.
Investment Casting
Copper investment casting wastewater is generated during
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investment mold backupf hydroblast cleaning of investment
castings, and the collection of dust resulting from the
hydroblasting of castings and the handling of the investment
material. Operations generating investment casting wastewaters
are sometimes called lost wax, lost pattern, hot investment, or
precision casting processes.
An estimated 16.9 million gallons of process wastewater are
generated each year by copper investment casting processes that
discharge wastewater. This represents 0.1 percent of the total
raw process wastewater generated by discharging facilities within
the copper subcategory. None of this wastewater quantity is
discharged to navigable waters, while 100 percent of copper
investment casting wastewater discharged is discharged to PQTW's.
No plant with this process segment practices recycle. The
applied flow rates for this process segment are summarized in
Table V--6, and range from 3,000 gallons/ton to 68,550
gallons/ton. As discussed in Section IX, aluminum, copper and
ferrous investment casting applied flow rates are considered
together because half of the investment casting plants surveyed
cast all three metals using the same or similar equipment.
No facility with this process segment reports having wastewater
treatment currently in-place.
Raw wastewater sampling data that characterize copper investment
casting wastewater are not available. Because of the expected
similarity in discharges from the copper mold cooling, copper
direct chill casting, and the copper dust collection process
segments (for which raw wastewater data are available) and the
mold backup, hydroblast, and dust collection processes character
istic of copper investment casting, the Agency relied on a
composite transfer from these copper process segments to the
copper investment casting segment. EPA calculated a straight
average of available data for the copper dust collection, copper
mold cooling, and copper direct chill casting segments to
characterize copper investment casting wastewater. The resulting
composite is expected to be representative of the levels of toxic
metal, toxic organic, nonconventional, and conventional
pollutants discharged from the copper investment casting process
segment.
Melting Furnace Scrubber
A schematic of a copper foundry employing a melting furnace is
presented in Figure II1-4. Melting furnace scrubber wastewater
is generated during the removal of dust and fumes from furnace
exhaust gases in a scrubber, when water or process wastewater is
used as a cleaning medium. The dust and fumes are generated by
melting or holding furnace operations and are expelled in the
exhaust gases from these operations. Wastewater from pouring
floor, pouring ladle, and transfer ladle fume scrubbing is also
included when the fumes from these operations are collected in an
air duct system common with the melting or holding furnace fumes.
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An estimated 144 million gallons of process wastewater are
generated each year by copper melting furnace scrubber processes
that discharge wastewater. This represents 1.2 percent of the
total raw process wastewater generated by discharging facilities
within the copper subcategory. One hundred percent of the copper
melting furnace scrubber wastewater discharged is dis-charged to
navigable waters, while none is discharged to POTW's. No plants
with this process segment practice recycle and sup-plied
sufficient information to calculate a recycle rate. The applied
flow rates for this process segment are summarized in Table V-13,
and range from 0.81 gallons/1,000 scf to 9.54 gallons/1,000 scf.
One of four facilities with this process segment reports having
wastewater treatment currently in-place. Plant #25005 reports a
cooling tower, lime and caustic addition, clarification, and
vacuum filtration.
Raw wastewater sampling data that characterize copper melting
furnace scrubber wastewater are not available. All data used to
characterize copper melting furnace scrubber wastewater have been
transferred from the copper dust collection scrubber segment.
Both of these segments generate wastewaters from the wet
scrubbing of dusts and fumes related to copper metal molding and
casting operations. Pouring floor and pouring ladle fumes can
either be routed to a melting furnace scrubber or a dust
collection scrubber depending on a plant's actual exhaust duct
configuration. Because both melting furnace scrubbers and dust
collection scrubbers are employed on air flows with similar
characteristics, wastewaters from both segments should contain
similar levels of toxic metals, organics, conventional, and
nonconventional pollutants.
Mold Cooling
Mold cooling wastewater originates from the direct spray cooling
of a mold or die, or of the casting, in an open mold. Water that
circulates in a noncontact cooling water system in the interior
of a mold is not considered mold cooling process wastewater
unless it leaks from the system and is commingled with other
process wastewaters,
An estimated 3,307 million gallons of process wastewater are
generated each year by copper mold cooling processes that
discharge wastewater. This represents 27.5 percent of the total
raw process wastewater generated by discharging facilities within
the copper subcategory. Fifty-nine percent of copper mold
cooling wastewater discharged is discharged to navigable waters,
while 41 percent is discharged to POTW's. Five plants with this
process segment practice recycle and supplied sufficient
information to calculate a recycle rate. These recycle rates
ranged from 92 percent to 99.5 percent. The applied flow rates
for th:s process segment are summarized in Table V-14, and range
froir. VJ.7 gal/ton to 12,817 gal/ton.
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Six of 11 facilities with this process segment report having
wastewater treatment currently in place. Three plants have
cooling towers, one plant has oil skimming, two plants employ
chemical addition and solids removal, and one plant has a
settling lagoon.
Raw wastewater sampling was performed at two facilities to
characterize copper mold cooling process wastewater. This raw
wastewater data is summarized in Table V-36. These data show
treatable concentrations of toxic organic and metal pollutants,
oil and grease, and suspended solids.
Plant 04736, Figure V-5, uses a mold cooling and casting quench
operation (sample point D). This process operates with a high
degree of recycle, with makeup via a float valve. An auxiliary
holding tank is installed to maintain a water balance in this
system.
Plant 06809, Figure V-6, recycles its mold cooling (sample point
C) wastewater through a cooling tower. Overflow from the hot
wells serves as a blowdown from this recycle system. This
blowdown undergoes treatment (sedimentation and skimming) in a
central treatment system. The mold cooling wastewater comprises
3 percent of the total flow to the central lagoon.
FerroujB Subcategory
An estimated 68.95 billion gallons of raw process wastewater are
generated each year by discharging facilities in the ferrous
subcategory. Fifty-four percent of this wastewater is generated
by facilities discharging to navigable waters, and 46 percent is
generated by facilities discharging to POTW's, Plants in the
ferrous subcategory account for approximately 82 percent of the
raw wastewater generated by plants in the metal molding and
casting industry.
Casting Cleaning
Casting cleaning wastewater originates from the application of
water to a caat product (casting) to rid it of impurities such as
die lubricants or sand. Casting cleaning wastewater does not
include wastewater that originates from the rinsing of castings
produced by investment casting processes} that wastewater is
regulated under investment casting.
An estimated 294 million gallons of process wastewater are
generated each year by ferrous casting cleaning processes that
discharge wastewater. This represents 0.4 percent of the total
raw process wastewater generated by discharging facilities with
in the ferrous subcate§ory» Eighty-four percent of this
wastewater quantity is discharged to navigable waters, while 16,5
percent is discharged to POTW's. Two plants with this process
segment practice recycle and supplied sufficient information to
calculate a recycle rate. These recycle rates ranged from SO
percent to 95 percent. The applied flow rates for this process
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segment are summarized in Table V-15, and range from 0.14 gal/ton
to 4,831 gal/ton.
Eleven of 17 facilities with this process segment report having
wastewater treatment currently in-place. One plant has emulsion
breaking, three have oil removal, two have chemical addition, 11
have settling devices, and three have filters.
Raw wastewater sampling was performed at one facility to
characterize ferrous casting cleaning process wastewater. This
raw wastewater data is summarized in Table V-37. Casting
cleaning water is characterized by the presence of treatable
concentrations of toxic metal pollutants, oil and grease, and
suspended solids.
Casting cleaning wastewater at Plant 10837, Figure V-14, was
sampled. Samples were taken at point H, casting washwater tank,
to characterize this stream. Plant 10837 has a treatment system
consisting of equalization, emulsion breaking, chemical addition,
clarification/ and sand filtration.
Casting Quench
Figure III-5 presents a general process and water flow diagram of
a representative ferrous casting facility. In this process,
process wastewaters are generated as a result of quenching
castings in contact cooling water. Quenching of the castings
takes place either subsequent to casting or in a heat treatment
operation following the casting operation.
An estimated 3,042 million gallons of process wastewater are
generated each year by ferrous casting quench processes that
discharge wastewater. This represents 4.4 percent of the total
raw process wastewater generated by discharging facilities within
the ferrous subcategory. Fifty-five percent of ferrous casting
quench wastewater discharged is dis-charged to navigable waters,
while 45 percent is discharged to POTWs. Twenty-four plants
with this process segment practice recycle and supplied
sufficient information to calculate a recycle rate. These
recycle rates ranged from 54 percent to 100 percent. The applied
flow rates for this process segment are summari2ed in Table V-16,
and range from 0.13 gal/ton to 8,229 gal/ton.
Twenty-eight of 62 facilities with this process segment report
having wastewater treatment currently in-place. Eight plants
employ cooling towers, two plants have oil removal, 19 plants use
settling devices, and two plants have filters.
Raw wastewater sampling was performed at two facilities to
characterize ferrous casting quench process wastewater. This raw
wastewater data is summarized in Table V-38. Casting quench
water is characterized by treatable concentrations of toxic
organic and metal pollutants, and suspended solids.
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Plant 20007, Figure V-23, operates a casting quench operation.
Samples were taken at point C to characterize this water.
Treatment at this plant consists of sedimentation using alum and
polymer flocculation, prior to discharge to a POTW.
Plant 51115, Figure V-30, operates a casting quench operation
{sample point 5). City water is used in quench tanks to rapidly
cool steel castings. Quench water is completely reused except
for emergency discharges to a sanitary sewer,
Dust Collection Scrubber
A general process and water flow diagram of a typical ferrous
dust collection scrubber system is presented in Figure III-5.
Dust collection scrubber wastewater originates in the removal of
dust from air in a scrubber, when water or process wastewater is
used as a cleaning medium. The dust may originate with sand
preparation, sand molding, core making, sand handling and
transfer, the removal of sand from the casting (including shake-
out and shot-blasting), or other dust sources on the foundry
floor, Wastewater that originates from pouring floor, pouring
ladle, and transfer ladle fume scrubbing also is included when
these fumes are collected in an air duct system common with sand
dusts. Wastewater that originates from core and mold making fume
scrubbing is also included in dust collection scrubbing, except
when such fumes are cleaned in a separate scrubbing device
dedicated to the core and mold making fumes, and the resulting
wastewater is then contract hauled or sent to a reclaimer.
Wastewater that originates from dust collection scrubbers
associated with investment casting operations are regulated under
the investment casting process segment.
An estimated 31,693 million gallons of process wastewater are
generated each year by ferrous dust collection scrubber processes
that discharge wastewater. This represents 46 percent of the
total raw process wastewater generated by discharging facilities
within the ferrous subcategory. Fifty-two percent of ferrous
dust collection scrubber wastewater discharged is discharged to
navigable waters, while 48 percent is discharged to PQTW's. One
hundred twenty-seven plants with this process segment practice
recycle and supplied sufficient information to calculate a
recycle rate. These recycle rates ranged from 18 percent to 100
percent. The applied flow rates for this process segment are
summarized in Table V-17f and range from 0.00036 gal/1,000 SCF to
105 gal/1,000 SCF.
Ninety-four of 194 facilities with this process segment report
having wastewater treatment currently in-place. Five plants
report using cooling towers, one plant reports emulsion breaking,
14 plants employ oil removal technology, 14 plants employ
chemical addition, 88 plants have settling devices, nine plants
use filtration, and one plant reports using powdered activated
carbon.
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Raw wastewater sampling was performed at 14 facilities to
characterize ferrous dust collection scrubber process wastewater.
This raw wastewater data is summarized in Table V-39. Ferrous
dust collection scrubber water is characterized by treatable
concentrations of toxic organic and metal pollutants, oil and
grease, phenols, and suspended solids.
Plant 06956, Figure V-7, generates wastewaters from dust
collection (sample point J), melting furnace scrubber (sample
point H), and slag quenching (sample point K) operations. These
wastewaters are combined for treatment. The wastewaters are
first treated in a clarifier with polymer added to enhance solids
removal and lime added for metals precipitation. The clarifier
effluent flows to a lagoon from which a portion of the treated
wastewaters are recycled to the processes listed above. The
lagoon not only provides system holding capacity but also
provides additional solids removal capability. Clarifier sludge
is transported to a landfill disposal site. The overall recycle
rate of this combined system is 95 percent; the remainder is
discharged to a receiving stream.
Plant 07929, Figure V-9, has operated nine dust collection
scrubbers at 100 percent recycle of process wastewater since 1973
(sample points C, D, F, G, H, J). These nine scrubbers remove
airborne particulates generated in the casting shakeout area,
core room mullers, pouring, casting cooling lines, sand handling
and transfer system, and the molding floor and molding line
areas. Western bentonite clay is used in the foundry sand. A
two compartment concrete settling tank was installed in 1973.
Only one settling compartment is used at a time, and, as
necessary, the compartments are switched to allow for sludge
removal. The solids are landfilled on company property. An
inertial grit separator was installed in 1978. Prior to the
installation of the grit separator, the scrubbers would become
fouled approximately once per month. The fouling was believed by
plant personnel to be caused by bentonite clay. The cleaning of
all the scrubbers required a maintenance effort of three men for
three 8-hour shifts. At the time of the installation of the grit
separator, a maintenance program employing a 1,000 psi pump and
hand held cleaning wand was initiated to clean the scrubbers on a
routine basis. All scrubber cleaning is performed one weekend
per month by one maintenance man and a helper.
Plant 09441, Figure V-12, has a dust collection scrubber. Water
ia recycled at a rate of 21 gal/min, and is batch dumped twice a
week. These batch dumps (sample point E) are treated with
primary settling in a pond prior to discharge.
Plant 10837, Figure V-14, operates a dust collection scrubber
system for a mold making shakeout operation. Water from this
scrubber (sample point D) is treated through polymer-aided
clarification and sand filtration prior to discharge to a surface
water.
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Plant 15520, Figure V-17, is a large foundry with a complex water
balance. Dust collection scrubber process wastewaters {sample
points G and E), slag quench process wastewaters, and sand
washing process wastewaters are settled and recycled with makeup
from noncontact cooling water. As water balance upsets occur,
overflow is periodically discharged to a POTW.
Plant 15654, Figure V-18, has a sand dryer scrubber which was
sampled (sample point G). This water is continually recirculated
through a casting wheel cooling water system, except for
evaporative losses,
Plant 17230, Figure V-2Q, has a dust collection scrubber system
consisting of dust collectors and settling and recirculation
tanks. Samples of dust collection scrubber water were collected
at sample point E.
Plant 20007, Figure V-23, has several dust collection scrubbers.
Wastewater from three of these scrubbers, the North End Scrubber,
and South End Scrubber Nos. 10 and 15, were commingled at the
time of sampling (sample point B). The commingled scrubber
wastewater is treated by flocculant addition and clarification,
prior to discharge to a POTW.
Plant 20009, Figure V-24, has six wet dust collection scrubbers.
Wastewater from two of the scrubbers, the kiln dust scrubber and
the chromite scrubber, are commingled with kiln cooler water.
This commingled wastewater was sampled (sample point D), The
commingled wastewater is settled in a series of four lagoons.
Settled sludge from the ponds is removed to a landfill. Forty
percent of the lagoon water is discharged by overflow to a POTW,
and 60 percent of the lagoon wastewater is discharged to a
surface water. The remaining four scrubbers operate with an
overflow to a POTW. Wastewater from one of these scrubbers,
scrubber No. 3, was sampled (sample point G).
Plant 50000, Figure V-27, has a shakeout dust collection
scrubber. Wastewater from this scrubber (sample point E) is
treated through chemical addition and clarification, prior to
discharge to a surface water.
Plant 50315, Figure V-28, generates process wastewater from
scrubbers which clean dusts from sand molding operations (sample
point 2). The process wastewater drains to a lagoon for
settling. One hundred percent of this process wastewater has
been recycled back to the dust collection scrubbers since 1974.
Plant 51115, Figure V-30, has two interconnected 100 percent
recycle process wastewater systems. The treatment system was
originally installed in 1959. Prior to 1976, process wastewater
was discharged to a navigable water. In 1976 this discharge was
eliminated, when 100 percent recycle of the process wastewater
was achieved. Three scrubbers which clean dusts from the core
room and shakeout area are in operation at this foundry. Process
wastewaters from the sand washer and the dust scrubbers (sample
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point 3} flow by gravity to a collection tank. Water in the
collection tank flows via gravity to the grit building where
alum/ polymer, and flocculant aids are added. Solids are removed
in a drag tank. Wastewater from the drag tank flows to a
settling basin, where it is pumped as needed to the dust
collectors and sand washing equipment. Problems were encountered
with the 100 percent recycle system immediately after closing the
loop. These problems were: (1) the determination of the correct
amount of polymer addition required for optimum settling took a
number of weeks; (2) during this transition period plugging of
the scrubbers occurred; and (3) a larger than normal amount of
solids collected in the settling basin. However, after the
correct amount of polymer addition was determined and the proper
water balance was achieved throughout the system, these problems
were eliminated. In an effort to confirm the status of 100
percent recycle systems, the Agency contacted Plant 51115 in
1983. Plant 51115 indicated that recycle of dust collection
scrubber water had been discontinued and dust collection scrubber
wastewater was now discharged to a surface water after settling
in a drag tank. No reason for the change in recycle status was
given.
Plant 53642, Figure V-35, has a scrubber system for the cleaning
of dusts collected in the molding, core room, pouring, cooling,
and cleaning areas (sample point 6). The process wastewater
flows to a primary settling tank and then ig pumped to a cyclone
separator. The cyclone underflow flows to a classifier for
dewatering and removal of solids, with the settled wastewaters
being returned to the primary settling tank. The upflow from the
cyclones goes to a second tank for recycle, with a blowdown {10
percent) to a thickener. Alum and polymer are added at the
thickener. The underflow goes to a vacuum filter. The filter
cake goes to a landfill, and the filtrate is returned to the
thickener. The thickener overflow is reused or discharged to a
surface water.
Plant 59101, Figure V-45, has a series of 12 bulk bed washer type
scrubbers in the foundry for the cleaning of molding and cleaning
dusts. These package scrubber units make use of internal
recycle, The process wastewater from these units (sample point
3) is pumped to a collection sump and then to a lagoon. Overflow
from the lagoon is discharged to a surface water.
Grinding Scrubber
Grinding scrubber wastewater originates from the removal of
grinding dust from air in a scrubber, when water or process
wastewater is used as a cleaning medium. Grinding dust is
generated during the mechanical abrading, or preliminary grinding
of castings following removal from the mold.
An estimated 1,897 million gallons of process wastewater are
generated each year by ferrous grinding scrubber processes that
discharge wastewater. This represents 2.8 percent of the total
raw process wastewater generated by discharging facilities within
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the ferrous subcategory. Fifty-three percent of ferrous grinding
scrubber wastewater discharged is discharged to navigable waters,
while 47 percent is discharged to POTWs. Twelve plants with
this process segment practice recycle and supplied sufficient
information to calculate a recycle rate. These recycle rates
ranged from 50 percent to 100 percent. The applied flow rates
for this process segment are summarized in Table V-18, and range
from 0.006 gal/1,000 SCF to 78.26 gal/1,000 SCF.
Sixteen of the 25 facilities with this process segment report
having wastewater treatment currently in-place. Four plants use
oil removal technology, two plants have chemical addition, 16
plants have settling devices, and three plants have filters.
Raw wastewater sampling data that characterize ferrous grinding
scrubber wastewater are not available. All data used to
characterize ferrous grinding scrubber wastewater have been
transferred from the magnesium grinding scrubber segment. Both
of these segments generate wastewater from the wet scrubbing of
grinding dusts generated by processing a non-toxic metal (i.e.,
iron and magnesium) casting, using similar technology and
equipment. Therefore, wastewaters from both segments should
contain similar levels of toxic metals, organics, conventional,
and nonconventional pollutants.
Investment Casting
Investment casting wastewater is generated during investment mold
backup, hydroblast cleaning of investment castings, and the
collection of dust resulting from the hydroblasting of castings
and the handling of the investment material. Operations
generating investment casting wastewaters are sometimes called
lost wax, lost pattern, hot investment, or precision casting
processes.
An estimated 2.3 million gallons of process wastewater are
generated each year by ferrous investment casting processes that
discharge wastewater. This represents 0.003 percent of the total
raw process wastewater generated by discharging facilities within
the ferrous subcategory. None of the ferrous investment casting
wastewater discharged is discharged to navigable waters, while
100 percent is discharged to POTW's. No plant that practices
recycle of ferrous grinding scrubber water was identified. The
applied flow rates for this process segment are summarized in
Table V-6, and range from 3,000 gal/ton to 68,550 gal/ton. As
discussed in Section IX, aluminum, copper, and ferrous investment
casting applied flow rates are considered together because half
of the investment casting plants surveyed cast all three metals
using the same or similar equipment.
No facility with this process segment reports having any
wastewater treatment currently in-place.
Raw wastewater sampling data that characterize ferrous investment
casting wastewater are not available. All data used to
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characterize ferrous investment casting wastewater have been
transferred from the aluminum investment casting segment. Both
of these segments generate wastewater during investment mold
backup, hydroblast cleaning of investment castings, and the
collection of dust resulting from the hydroblasting of castings
and the handling of the investment material. Many plants conduct
both ferrous and aluminum (both non-toxic metals) investment
casting using the same or similar technology and equipment.
Therefore/ wastewaters from both segments should contain similar
levels of toxic metals, organics, conventional, and
nonconventional pollutants.
Melting Furnace Scrubber
An estimated 18,136 million gallons of process wastewater are
generated each year by ferrous melting furnace scrubber processes
that discharge wastewater. This represents 26.3 percent of the
total raw process wastewater generated by discharging facilities
within the ferrous subcategory. Fifty-one percent of ferrous
melting furnace scrubber wastewater discharged is discharged to
navigable waters, while 49 percent is discharged to POTW's.
Eighty-six plants with this process segment practice recycle and
supplied sufficient information to calculate a recycle rate.
These recycle rates ranged from 40 percent to 100 percent. The
applied flow rates for this process segment are summarized in
Table V-19, and range from 1 gal/1rOOO SCF to 125 gal/1,000 SCF.
Seventy-eight of 119 facilities with this process segment report
having wastewater treatment currently in-place. One plant
reports using a cooling tower, 10 plants have oil removal
technology, 29 plants employ chemical neutralization, 63 plants
use settling devices, four plants employ filters, and one plant
uses evaporation.
A general process and water flow diagram of a representative
ferrous melting furnace scrubber operation is presented in Figure
III-5. Melting furnace scrubber wastewater is generated during
the removal of dust and fumes from furnace exhaust gases in a
scrubber, when water or process wastewater is used as a cleaning
medium. The dust and fumes are generated by melting or holding
furnace operations and are expelled in the exhaust gases from
these operations. Wastewater from pouring floor, pouring ladle,
and transfer ladle fume scrubbing is also included when the fumes
from those operations are collected with the melting or holding
furnace fumes in a common air duct system.
Raw wastewater sampling was performed at six facilities to
characterize ferrous melting furnace scrubber process wastewater.
This raw wastewater data is summarized in Table V-40. Melting
furnace scrubber water is characterized by toxic organic and
metal pollutants, oil and grease, phenols, and suspended solids.
Plant 06956, Figure V-17, generates wastewaters from dust
collection {sample point J), melting furnace scrubber (sample
point H), and slag quenching (sample point K) operations. These
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wastewaters are combined for treatment. The wastewaters are
first treated in a clarifier with polymer added to enhance solids
removal and lime added to precipitate metals. The clarifier
effluent flows to a lagoon from which a portion of the treated
wastewaters are recycled to the processes listed above. The
lagoon not only provides system holding capacity but also
provides additional solids removal capability. Clarifier sludge
is transported to a landfill disposal site. The overall recycle
rate of this combined system is 95 percent; the remainder is
discharged to a receiving stream.
Plant 09441, Figure V-12, a gray iron foundry, operates two
melting furnace scrubbers. Wastewater from these two scrubbers
are commingled (sample point B), settled in a tank with caustic
addition, and recycled. Overflow from the settling tank is
combined with other flows, including slag quench and dust
collection scrubber water, settled in a pond, and then
discharged.
Plant 17230, Figure V-20, has a cupola emissions control system
which includes a wet cap, a Venturi scrubber, and a mist
eliminator. Water from these three units is combined and samples
were taken of this combined flow (sample point B). This water is
recycled through a settling tank where sludge is removed.
Plant 50000, Figure V-27, has a Venturi scrubber and a cupola wet
cap. Lake water is used first in the Venturi scrubber and then
in the wet cap, A sample was taken of the water exiting the wet
cap (sample point C). This water is further used in a slag
quench operation, and then treated with chemical addition and
clarification prior to surface water discharge.
Plant 55217, Figure V-38, generates process wastewaters from the
melting furnace scrubber on a triplex cupola arrangement. The
process wastewaters are collected in a slurry tank (sample point
2). Caustic is added, and the wastewater is pumped to a large
lagoon that is shared with another plant. Since 1974, all
process wastewater from the melting furnace scrubber has been
recycled.
Plant 58589, Figure V-44, has a melting furnace scrubber process
wastewater which is collected in a separator, and then pumped to
a large sump (sample point 2). After settling overnight, the
contents of the sump are siphoned to a second sump. Water from
this second sump is recycled to the quench chamber scrubber the
next day. This plant recycles all of its melting furnace process
wastewaters. Solids are removed from the first sump on a bi-
monthly basis.
Mold Cooling
Mold cooling wastewater originates from the direct spray cooling
of a mold or die, or of the casting in an open mold. Water that
circulates in a noncontact cooling water system in the interior
of a mold is not considered mold cooling process wastewater
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unless it leaks from the system and is commingled with other
process wastewaters.
An estimated 1,435 million gallons of process wastewater are
generated each year by ferrous mold cooling processes that
discharge wastewater. This represents 2.1 percent of the total
raw process wastewater generated by discharging facilities within
the ferrous subcategory. Eighty-three percent of ferrous mold
cooling wastewater discharged is discharged to navigable waters/
while 17 percent is discharged to POTW's, Seven plants with this
process segment practice recycle and supplied sufficient
information to calculate a recycle rate. These recycle rates
ranged from 14 percent to 100 percent. The applied flow rates
for this process segment are summarized in Table V-2Q, and range
from 55 gal/ton to 9,434 gal/ton.
Thirteen of 14 facilities with this process segment report having
wastewater treatment currently in-place. Two plants have cooling
towers, four have oil removal technology, six have chemical
addition, and nine have settling devices.
Raw wastewater sampling was performed at one facility to
characterize ferrous mold cooling process wastewater. This raw
wastewater data is summarized in Table V-41.
Wastewater samples from this plant were not analyzed for toxic
organic pollutants. All organics data for the ferrous mold
cooling process segment have been transferred from the ferrous
casting quench process segment. Both of these segments generate
wastewater from the contact cooling of metallic mold and casting
surfaces at ferrous metal molding and casting plants. Data
available for other pollutants indicate that ferrous mold cooling
and casting quench wastewater have similar characteristics,
Therefore, wastewaters from both segments should contain similar
levels of toxic organic pollutants.
Plant 51026, Figure V-29, generates casting quench, mold cooling
{sample points 3 and 6), slag quench, dust collection, and sand
washing wastewaters which are drained to a series of lagoons, and
after 84 hours retention time are discharged to a surface water.
The first lagoon in the series is periodically dredged, and the
sludge is trucked to a nearby landfill. During this clean-out
operation, the flow is diverted to a duplicate lagoon.
Slag Quench
Figure III-5 presents a general process and water flow diagram of
a representative ferrous slag quenching operation. In this
operation, the slag removed during the melting operation is
quenched in water in order to cool and thus solidify the slag.
The quenched slag is subsequently removed for disposal or reuse
in other applications.
An estimated 8,336 million gallons of process wastewater are
generated each year by ferrous slag quench processes that
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discharge wastewater. This represents 12.1 percent of the total
raw process wastewater generated by discharging facilities within
the ferrous subcategory. Fifty-nine percent of ferrous slag
quench wastewater discharged is discharged to navigable waters,
while 41 percent is discharged to PQTWs. Fifty-two plants with
this process segment practice recycle and supplied sufficient
information to calculate a recycle rate. These recycle rates
ranged from 25 percent to 100 percent. The applied flow rates
for this process segment are summarized in Table V-21, and range
from 2.4 gal/ton to 64,000 gal/ton.
Sixty-two of 89 facilities with this process segment report
having wastewater treatment currently in-place. Three plants
have cooling towers, 10 plants use oil removal technology, nine
plants practice chemical addition, 60 plants employ settling
devices, three plants use filters, and one plant uses
evaporation.
Raw wastewater sampling was performed at five facilities to
characterize ferrous slag quench process wastewater. This raw
wastewater data is summarized in Table V-42, Slag quench water
is characterized by treatable concentrations of toxic organic and
metal pollutants, oil and grease, and suspended solids.
Plant 06956, Figure V-7, generates wastewaters from dust
collection (sample point J), melting furnace scrubber (sample
point H}, and slag quenching (sample point KJ operations. These
wastewaters are combined for treatment. The wastewaters are
first treated in a clarifier with polymer added to enhance solids
removal and lime added for pH control. The clarifier effluent
flows to a lagoon from which a portion of the treated wastewaters
are recycled to the processes listed above. The lagoon not only
provides system holding capacity but also provides additional
solids removal capability. Clarifier sludge is transported to a
landfill disposal site. The overall recycle rate of this
combined system is 95 percent; the remainder is discharged to a
receiving stream.
Plant 09441, Figure V-12, generates slag quench wastewater
{sample point D), along with dust collection scrubber, melting
furnace scrubber, and noncontact cooling waters. These waters
are combined and treated in a settling pond prior to discharge.
Plant 51026, Figure V-29, generates slag quench (sample point 7),
mold cooling, casting quench, dust collection scrubber, and sand
washing process wastewaters which are drained to a series of
lagoons, and after 84 hours retention time are discharged to a
surface water. The first lagoon in the series is periodically
dredged with the sludge trucked to a nearby landfill. During
this clean-out operation, the flow is diverted to a duplicate
lagoon.
Plant 55217, Figure V-38, applies water to the slag discharge of
a cupola. These wastewaters convey the solidified slag to a slag
quench pit (sample point 3), where a conveyor mechanism removes
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the slag. The slag is transported to a disposal site. Slag
quenching wastewaters are recycled, at a rate of 95 percent, from
the pit to the process. The discharge from this quenching
process is delivered to a large lagoon which is shared with plant
50315. Since 1974, all process wastewater has been recycled.
Plant 56123, Figure V-39, has a slag quench pit, from which slag
quench water is discharged (sample point 2) to a separation sump.
From this sump, water is discharged to a sanitary sewer.
Wet Sand Reclamation
A general process and water flow diagram of a representative sand
washing and reclamation system is presented in Figure III-5.
In this operation, wastewaters are generated as a result of using
water to wash used casting sand. The waters are used to remove
impurities/ primarily "spent" binders and sand, from the casting
sand prior to its reuse in the molding processes. The sand and
binders become "spent" as a result of the heat present in the
casting process.
An estimated 4,113 million gallons of process wastewater are
generated each year by ferrous wet sand reclamation processes
that discharge wastewater. This represents 6 percent of the
total raw process wastewater generated by discharging facilities
within the ferrous aubcategory. Sixty percent of ferrous wet
sand reclamation wastewater discharged is discharged to navigable
waters, while 40 percent ia discharged to POTW's. Six plants
with this process segment practice recycle and supplied
sufficient information to calculate a recycle rate. These
recycle ratea ranged from 30 percent to 99 percent. The applied
flow rates for this process segment are summarized in Table V-22,
and range from 59.8 gal/ton to 3,085 gal/ton.
Thirteen of 16 facilities with this process segment report having
wastewater treatment currently in-place. Two plants employ oil
removal devices, and all 13 plants use settling devices*
Raw waatewater sampling was performed at seven facilities to
characterize ferrous wet sand reclamation process wastewater.
This raw wastewater data is summarized in Table V-43. Wet sand
reclamation water is characterized by treatable concentrations of
toxic organic and metal pollutants, oil and grease, phenols, and
suspended solids.
Plant 15520, Figure V-17, generates sand washing process
wastewaters {sample points J and K)r dust collection scrubber
process wastewaters, and slag quench process wastewaters which
are settled and recycled. Makeup water is from noncontact
cooling water. Overflow is discharged to a POTW.
Plant 20007, Figure V-23, has a sand washing operation. Samples
were taken of this water {sample point D) following commingling
with dust collection scrubber water. This stream is treated by
146
-------
flocculation and clarification prior to POTW discharge.
Plant 20009, Figure V-24, operates a sand reclamation process.
The sand washing process wastewater (sample point B) is settled
in a series of four lagoons. Sixty percent of the process
wastewater is recycled, while 40 percent is discharged by
overflow to a POTW.
Plant 51026, Figure V-29, generates sand washing (sample point
2), mold cooling, casting quench, slag quench, and dust
collection scrubber process wastewaters which are drained to a
series of lagoons, and after 84 hours retention time are
discharged to a surface water. The first lagoon in the series is
periodically dredged with the sludge being trucked to a nearby
landfill. During this clean-out operation, the flow is diverted
to a duplicate lagoon.
At the time of sampling, Plant 51115, Figure V-30, generated dust
collection and sand washing wastewaters (sample point 2) which
were collected, treated with flocculants and sent to a drag tank*
The sludge from this settling operation was hauled to a landfill;
the overflow water was drained to a settling pond for additional
settling. Overflow from the settling basin flowed to a wet well.
This overflow water was then pumped to a tank, where it was
pumped (as needed) to the dust collectors and the sand washing
equipment. This was a complete recycle system. In an effort to
confirm 100 percent recycle systems conducted in 1983, EPA
contacted plant 51115. At that time, plant 51115 indicated that
wet sand reclamation operations had been discontinued.
Plant 51473, Figure V-31, has a sand washing process. The sand
from shakeout is conveyed to a screen, A magnetic separator
removes all metallic particles from the sand. The screen
oversize (3/8 in.) goes to a mixer vessel where city water is
added. This is thoroughly agitated and then pumped to a slurry
tank. The slurry tank meters the mix to a dewater table, where
the solids are transported by screw conveyor to a rotary dryer.
The underflow from the dewater table is pumped to a settling tank
(sample point 2). The settling tank is cleaned out weekly, and
the solids are removed to landfill. The treated effluent is
discharged to a receiving stream.
Plant 59101, Figure V-45, has a sand washing system to reclaim
sand for reuse. The process wastewater from this operation
{sample point 2) flows to lagoons. The lagoons are arranged to
give maximum use of the land area. The inlet to the first lagoon
is arranged so that the heavy solids can be removed readily. The
lagoon overflow is discharged to a surface water.
Magnesium Subcategory
An estimated 2.65 million gallons of raw process wastewater are
generated each year by discharging facilities in the magnesium
subcategory. Seven percent of this wastewater is generated by
facilities discharging to navigable waters, and 93 percent is
147
-------
generated by facilities discharging to POTW's. Plants in the
magnesium subcategory account for approximately 0.003 percent of
the raw wastewater generated by plants in the metal molding and
casting industry.
Casting Quench
Casting quench wastewater originates from the immersion of a hot
casting in a water bath to rapidly cool the casting, or to change
the metallurgical properties of the casting.
An estimated 0.181 million gallons of process wastewater are
generated each year by magnesium casting quench processes that
discharge wastewater. This represents 6.8 percent of the total
raw process wastewater generated by discharging facilities within
the magnesium subcategory. One hundred percent of the magnesium
casting quench wastewater discharged is discharged to navigable
waters, while none is discharged to POTW's. No plant with this
process segment that practices recycle has been identified. The
applied flow rates for this process segment are summarized in
Table V-23, No plant reported sufficient information to
calculate an applied flow rate. Applied flow rate data for the
magnesium casting quench segment has been transferred from the
zinc casting quench segment.
No facility with this process segment reports having any
wastewater treatment currently in-place.
Raw wastewater sampling data that characterize magnesium casting
quench wastewater are not available. All data used to
characterize magnesium casting quench wastewater have been
transferred from the aluminum casting quench segment. Both of
these segments generate wastewater from the quenching of non-
toxic metal (i.e., aluminum and magnesium) castings, using
similar techniques and equipment. Data available for the
aluminum, copper, and ferrous subcategories indicate that the
pollutant load in casting quench wastewater from different
subcategories is similar. Therefore, wastewaters from the
aluminum and magnesium casting quench segment should contain
similar levels of toxic metals, organics, conventional, and
nonconventional pollutants.
Dust Collection Scrubber
A general process and water flow diagram of a typical magnesium
dust collection scrubber system is presented in Figure III-6.
Dust collection scrubber wastewater originates from the removal
of dust from air in a scrubber when water or process water is
used as a cleaning medium. The dust may originate with sand
preparation, sand molding, core making, sand handling and
transfer, the removal of sand from the casting (including shake-
out and shot-blasting), or other dust sources on the foundry
floor. Wastewater that originates from core and mold making fume
scrubbing is also included in dust collection scrubbing, except
when such fumes are cleaned in a separate scrubbing device
148
-------
dedicated to the core and mold making fumesr and the resulting
wastewater is then contract hauled or sent to a reclaimer.
An estimated 1.24 million gallons of process wastewater are
generated each year by magnesium dust collection scrubber
processes that discharge wastewater. This represents 46.6
percent of the total raw process wastewater generated by
discharging facilities within the magnesium subcategory. None of
this wastewater quantity is discharged to navigable waters, while
100 percent of the magnesium dust collection wastewater
discharged is discharged to POTW's. No plant with this process
segment that practices recycle was identified. The applied flow
rates for this process segment are summarized in Table V-24, and
range from 0.05 gal/1,000 SCF to 0.5 gal/1,000 SCF.
No facility with this process segment reports having any
wastewater treatment currently in-place.
Raw wastewater sampling data that characterize magnesium dust
collection wastewater are not available. All data used 'to
characterize magnesium dust collection scrubber wastewater have
been transferred from the magnesium grinding scrubber process
segment. Both of these segments generate wastewater as a result
of wet scrubbing of dusts generated during magnesium casting
operations. Therefore, wastewaters from both segments should
contain similar levels of toxic metals, organics, conventional,
and nonconventional pollutants.
Grinding Scrubber
Figure III-6 presents a general process and water flow diagram of
a representative magnesium grinding scrubber operation,
Scrubbers are provided on grinding systems in order to remove
particulate magnesium generated as a result of the grinding
operation. The scrubbing process not only serves to remove the
particulate magnesium as an airborne contaminant, but also
reduces the fire hazards which can result from an accumulation of
fine magnesium particles.
An estimated 1.24 million gallons of process wastewater are
generated each year by magnesium grinding scrubber processes that
discharge wastewater. This represents 46.6 percent of the total
raw process wastewater generated by discharging facilities within
the magnesium subcategory. None of this wastewater quantity is
discharged to navigable waters, while 100 percent of the
magnesium grinding scrubber wastewater discharged is discharged
to POTW's. Two plants with this process segment practice recycle
and supplied sufficient information to calculate a recycle rate.
These recycle rates ranged from 97 percent to 100 percent. The
applied flow rates for this process segment are summarized in
Table V-25. No plants reported sufficient information to
calculate an applied flow rate for this process segment. Applied
flow rate data for the magnesium grinding scrubber segment have
been transferred from the magnesium dust collection scrubber
segment.
149
-------
No facility with this process segment reports having any waste
water treatment currently in-place.
Raw wastewater sampling was performed at one facility to
characterize magnesium grinding scrubber process wastewater.
This raw wastewater data is summarized in Table V-44. Grinding
scrubber water is characterized by toxic organic and metal
pollutants, oil and grease, and suspended solids.
Plant 08146, Figure V-1Q, employs a magnesium dust collection
scrubber and a magnesium grinding scrubber (sample point B). The
process wastewaters from these scrubbers are discharged untreated
to a surface water.
Zinc Subcategory
An estimated 0.775 billion gallons of raw process wastewater are
generated each year by discharging facilities in the zinc
subcategory. Thirty-two percent of this wastewater is generated
by facilities discharging to navigable waters, and 68 percent is
generated by facilities discharging to POTW's. Plants in the
zinc subcategory account for approximately 1 percent of the raw
wastewater generated by plants in the metal molding and casting
industry.
Casting Quench
A general process and water flow diagram of a representative zinc
casting quench operation is presented in Figure III-7. The
process wastewater considered in this operation is that which is
discharged from the casting quench tanks.
An estimated 256 million gallons of process wastewater are
generated each year by zinc casting quench processes that
discharge wastewater. This represents 33.1 percent of the total
raw process wastewater generated by discharging facilities within
the zinc subcategory. Thirty-five percent of the zinc casting
quench wastewater discharged is discharged to navigable waters,
while 65 percent is discharged to POTW's. Nine plants with this
process segment practice recycle and supplied sufficient
information to calculate a recycle rate. These recycle rates
ranged from 33 percent to 100 percent. The applied flow rates
for this process segment are summarized in Table V-26, and range
from 5.5 gal/ton to 40,632 gal/ton.
Eleven of 32 facilities with this process segment report having
wastewater treatment currently in-place. One plant uses a
cooling tower, three plants practice emulsion breaking, seven
plants treat to remove oil and grease, seven plants practice
chemical addition, and two plants practice filtration.
Raw wastewater sampling was performed at two facilities to
characterize zinc casting quench process wastewater. This raw
wastewater data is summarized in Table V-45. Casting quench
water is characterized by treatable concentrations of toxic
150
-------
organic and metal pollutants, oil and grease, and suspended
solids.
Plant 10308, Figure V-13, has a zinc casting quench operation
(sample point B). Quench water is commingled with aluminum
casting quench water and other wastewater streams in a wet well.
Water from this well is treated with oil skimming, chemical
addition, and sedimentation prior to discharge to a land-locked
swamp.
Plant 18139, Figure V-21, has a number of die casting machines
and associated quench tanks (zinc casting quench is sample point
D) which are emptied on a scheduled basis. The schedule results
in the emptying of one 1,135.5 liter (300 gallon} quench tank
each operational day. Each quench tank is emptied about once a
month. The quench tank discharge mixes with melting furnace
scrubber process wastewater, aluminum casting quench tank
discharges, and other non-foundry discharges prior to settling
and skimming. The treated process wastewaters are discharged to
a POTH. The zinc quench process wastewater makes up 0.2 percent
of the total flow.
Die Casting
Die casting wastewater includes two types of wastewater
discharges: leakage of hydraulic fluid from hydraulic systems
associated with die casting operations, and the discharge of die
lubricants. Any process water used for the cooling of dies or
castings still contained in dies is not considered die casting
wastewater; rather, it is mold cooling wastewater.
An estimated 9.89 million gallons of process wastewater is
generated each year by zinc die casting processes that discharge
wastewater. This represents 1.3 percent of the total raw process
wastewater generated by discharging facilities within the zinc
subcateqory. Thirty-four percent of zinc die casting wastewater
discharged is discharged to navigable waters, while 66 percent is
discharged to POTH's. Two plants with this process segment
practice recycle and supplied sufficient information to calculate
a recycle rate. These recycle rates ranged from 83 percent to
100 percent. The applied flow rates for this process segment are
summarized in Table V-27, and range from 3.33 gal/ton to 41.4
gal/ton.
Eight of 20 facilities with this process segment report having
wastewater treatment currently in-place. Two plants use chromium
reduction, three plants use emulsion breaking, six plants remove
oils, five plants practice chemical addition, one plant has a
deep bed filter, and six plants employ settling devices.
Raw wastewater sampling was performed at two facilities to
characterize zinc die casting process wastewater. This raw
wastewater data is summarized in Table V-46. Die casting water
is characterized by toxic organic and metal pollutants, oil and
grease, phenols, and suspended solids.
151
-------
Plant 04622, Figure V-3, generates die casting process wastewater
(sample point B) which is hauled away on a contract basis by a
reprocessor.
Plant 12040, Figure V-15, has a zinc die casting operation.
Effluent from this operation was sampled {sample point C) prior
to being combined with aluminum die casting effluent in a
receiving tank. Oil is removed in this tank, and the effluent is
then pumped to a batch treatment system that consists of chemical
emulsion breaking and lime and settle treatment.
Melting Furnace Scrubber
Melting furnace scrubber wastewater is generated during the
removal of dust and fumes from furnace exhaust gases in a scrub
ber, when water or process wastewater is used as a cleaning
medium. The dust and fumes are generated by melting or holding
furnace operations and are expelled in the exhaust gases from
these operations. Wastewater from pouring floor, pouring ladle,
and transfer ladle fume scrubbing is also included when the fumes
from those operations are collected in an air duct system common
with the melting or holding furnace fumes.
A general process and water flow diagram of a representative zinc
melting furnace scrubber operation is presented in Figure III-7.
The process wastewater from these scrubbers may be either
recirculated within the scrubber equipment package (which
includes a settling chamber) or may flow to an external treatment
system and then be recycled back to the scrubber.
An estimated 447 million gallons of process wastewater are
generated each year by zinc melting furnace scrubber processes
that discharge wastewater. This represents 57,7 percent of the
total raw process wastewater generated by discharging facilities
within the zinc subcategory. Twenty-three percent of zinc
melting furnace wastewater discharged is discharged to navigable
waters, while 77 percent is discharged to POTW's. Seven plants
with this process segment practice recycle and supplied
sufficient information to calculate a recycle rate. These plants
reported recycle rates ranging from 69 to 99.8 percent. The
applied flow rates for this process segment are summarized in
Table V-28, and range from 0.24 gal/1,000 SCF to 24 gal/1,000
SCF.
Five facilities with this process report having wastewater
treatment currently in-place. Four plants have emulsion
breaking, two plants practice oil removal, five plants employ
caustic addition, five plants use settling devices, one plant has
a vacuum filter, and one plant has a pressure filter.
Representative raw wastewater sampling data that characterize
zinc melting furnace scrubber wastewater are not available. Data
available for the zinc melting furnace scrubber at plant 18139
had extremely high concentrations of total phenol and oil and
152
-------
grease. Oil and grease concentrations ranged from 646 mg/1 to
885 mg/1; total phenol ranged from 49,3 mg/1 to 123 mg/1. Based
on a review of available data on melting furnace scrubbers in
other subcategories, such concentrations are uncharacteristic o£
scrubber wastewaters. Therefore, all data used to characterize
zinc melting furnace scrubber wastewater have been transferred
from the ferrous melting furnace scrubber segment. Both of these
segments generate wastewater from the wet scrubbing of melting
furnace exhaust gases. The raw waste data for the ferrous
melting furnace scrubber segment show high levels of zinc, as
well as levels of other toxic organic, conventional, and
nonconventional pollutants that would be expected in zinc melting
furnace scrubber wastewater.
Mold Cooling
Mold cooling wastewater originates from the direct spray cooling
of a mold or die, or of the casting, in an open mold. Water that
circulates in a noncontact cooling water system in the interior
of a mold is not considered mold cooling process wastewater
unless it leaks from the system and is commingled with other
process wastewaters.
An estimated 61.7 million gallons of process wastewater are
generated each year by zinc mold cooling processes that discharge
wastewater. This represents 7.9 percent of the total raw process
wastewater generated by discharging facilities within the zinc
subcategory. Eighty percent of zinc mold cooling wastewater
discharged is discharged to navigable waters, while 20 percent is
discharged to POTW's. Four plants with this process segment
practice recycle and supplied sufficient information to calculate
a recycle rate. These recycle rates ranged from 95 percent to
100 percent. The applied flow rates for this process segment are
summarized in Table V-29, and range from 42.7 gal/ton to 4,860
gal/ton.
Three of 10 facilities with this process segment report having
wastewater treatment currently in-place. Plant 01334 employs
primary settling, plant 01707 has a cooling tower; and plant
10640 has a treatment scheme that includes emulsion breaking,
chemical addition, flocculation, and clarification.
Raw wastewater sampling data that characterize zinc mold cooling
wastewater are not available. All data used to characterize zinc
mold cooling wastewater have been transferred from the zinc
casting quench segment. Both of these segments generate waste
water from the contact cooling of metallic mold or casting
surfaces. Data available for the ferrous subcategory indicate
that mold cooling and casting quench wastewaters have similar
characteristics. Therefore, wastewaters from the zinc mold
cooling and casting quench segments should contain similar levels
of toxic metals, organics, conventional, and nonconventional
pollutants.
153
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Table V-1
APPLIED FLOW RATES FOR
ALUMINUM CASTING CLEANING
Applied Flow Rate
Callons/ton)
12040 14,270
07280 480
47992 183
154
-------
Table V-2
APPLIED FLOW RATES FOR
ALUMINUM CASTING QUENCH
Applied Flow Rate
Plant Code (gallons/ton)
10615 6,866
15265 3,543
11703 2,408
87799 1,975
12040 1,054
81703 757
04809 700
17089 581
14924 232
87598 159.7
07879 147
26767 145
14401 99.3
04675 56
00206 42.5
82200 38.5
25025 38.1
25023 32.4
19405 19
85120 14.6
87599 6.31
82118 1.65
14789 1.45
02869 NA
02905 NA
047^7 NA
06900 NA
13978 NA
18126 NA
20023 NA
82117 NA
87561 NA
89920 NA
NA - Data not reported.
155
-------
Table V-3
APPLIED FLOW HATES FOH
ALUMINUM DIE CASTING
Applied Flow Rate
Plant Cads . (gallons/ton)
1940S 600
89100 441
15265 361
03185 171.1
82100 119.5
82000 96.5
05878 85
81703 70
07138 70
80100 50
85120 49
20147 44.9
20114 44.9
82117 40
04675 37.8
80119 31.1
80597 31.0
16.9
82118 10
19275 8.7
12040 4.05
87799 2.1
18139 NA
NA - Data not reported.
156
-------
Table V-4
APPLIED FLOW RATES FOR
ALUMINUM DUST COLLECTION SCRUBBER
Applied Flow Rate
Plant Code (gallons/1000 SCF)
12040 10.4
19275 5.56
19275 5.56
19275 5.13
19275 5.1
19275 3.08
25025 2.5
17089 2.0
17089 2.0
17089 2.0
00206 1.82
20063 1.78
00206 1.5
00206 1.25
22121 0.3
20063 0.25
04704 0.1
22121 0.1
22121 0.08
22121 0.08
74992 0.06
20223 0,03
20223 0.03
05167 NA
07098 NA
14789 NA
NA - Data not reported.
157
-------
Table V-5
APPLIED FLOW RATES FOR
ALUMINUM GRINDING SCRUBBER
Applied Flow Rate
Plant Code fgalIons/1000 SCF)
11703 1.75
74992 0.063
04704 0.033
Table V-6
APPLIED FLOW RATES FOR
ALUMINUM, COPPER, AND FERROUS
INVESTMENT CASTING
Applied Flow Rate
(gallons/ton) Metal Cast
04704 68,550 Al - 80$
Cu - 15$
Fe - 51
05206 20,800 Al - 100$
20063 14,400 Al - 100$
01994 3,000 Al - 25%
Cu - 20$
Fe - 55$
158
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Table V-7
APPLIED FLOW RATES FOR
ALUMINUM MELTING FUBNACE SCBUBBEB
Applied Flow Bate
Plant Code (gallons/1,.000. SCFl
13562 12
13562 12
13562 12
17089 11.73
17089 11.73
17089 11.73
22121 11,73
20063 5
22121 0,43
12040 NA
20023 NA
20114 NA
NA - Data not reported.
159
-------
Table V-8
APPLIED FLOW RATES FOR
ALUHINUM MOLD COOLING
Applied Flow Rate
Plant Code (gallons/ton)
07138 202,300
04675 33,800
13562 14,460
20223 12,000
12040 10,940
87799 3,950
10615 2,860
87599 1,850
14401 1,655
19405 1,300
15265 723
19275 609
11665 506
85120 159
20063 103.2
06925 (15
11703 NA
20023 NA
(1) Cannot separate die casting and mold cooling water,
NA - Data not reported.
160
-------
Table V-9
APPLIED FLOW RATES FOR
COPPER CASTING QUENCH
Applied Flow Rate
Plant
NA - Data not reported.
16446 26,470
25004 20,731
25015 5,882
09125 3,859
04951 2,300
38846 1,120
12322 817
25013 610.3
25009 496
25007 460
25011 364
11740 140
20078 140
04184 100
06809 90.2
03525 60.3
25003 16.7
04851 8.93
19484 NA
20067 NA
40011 NA
161
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Table V-10
APPLIED FLOW RATES FOR
COPPER DIRECT CHILL CASTING
Applied Flow Rate
2001T 9,617
80091 7,007
80029 5,783
20066 3,130
80030 2,858
80079 NA
06809 NA
09979 NA
NA - Data not reported.
Table V-11
APPLIED FLOW RATES FOR
COPPER DUST COLLECTION SCRUBBED
Applied Flow Rate
Plant Code (gallons/1.000 SCF)
05934 11
09094 5
09094 5
09094 4.64
38840 4.29
40011 3*45
04851 0.09
12322 0.06
05946 0.03
03588 NA
15107 NA
19872 NA
31744 NA
NA - Data not reported.
1G2
-------
Table V-12
APPLIED FLOW RATES FOR
COPPER GRINDING SCRUBBER
Applied Flow Rate
Plant Code (galIons/1rOOP SCF)
04851 0.111
05934 NA
09094 NA
15382 NA
32543 NA
37947 NA
NA - Data not reported.
Table V-13
APPLIED FLOW RATES FOR
COPPER MELTING FURNACE SCRUBBER
Applied Flow Rate
Plant Code (gallons/1,000 SCF)
03588 9.54
05934 7.04
25005 0.81
163
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Table V-14
APPLIED FLOW RATES FOR
COPPER MOLD COOLING
Applied Flow Rate
Code C allons /tan A ___
NA - Data not reported.
2500? 12,817
25015 9,626
03525 7,352
20017 3,440
08951 1,458
25013 1,085
06809 395
08554 16
04736 NA
25001 NA
25004 NA
20067 NA
164
-------
Table V-15
APPLIED FLOW RATES FOR
FERROUS CASTING CLEANING
Applied Flow Rate
Plant Code ...^.I gall on p/ton)
80770 - 4,831
r.^50 4,453
02799 2,703
D6999 2,410
08285 1,519
10865 1,403
04033 1,088
20699 213
19933 199
09929 91.6
10837 9.67
17348 5,71
05658 4
05622 0.81
03118 0,14
19733 NA
NA - Data not reported.
165
-------
Table V-16
APPLIED FLOW RATES FOR
FERROUS CASTING QUENCH
Applied Flow Rate
Plant Code
11643 8,229
24566 5,818
86666 5,620
07882 5,505
15654 4,444
86119 4,132
05560 4,000
20011 2,237
08768 1,889
08223 1,600
20002 1,493
28634 1,391
83812 1,321
20000 1,320
20719 1,219
58589 1,200
00388 1,171
20003 1,170
19999 1,152
20007 1,098
13578 1,013
21175 884
18990 870
10388 583
07472 559
05691 553
19733 297.8
01665 291
15573 270
07024 256
14444 201
16502 157
11598 145
03901 144
08868 133
07898 125
80770 124
14761 110.3
06123 108
16934 52
04265 42.7
166
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Table V-16 (Continued)
APPLIED FLOW RATES FOR
FERROUS CASTING QUENCH
Applied Flow Rate
Plant Code
17015 HO. 33
01834 15.3
17017 11.4
09024 7.11
02495 4
09035 3.6
04621 0,13
02365 NA
04073 NA
05929 NA
06937 NA
09151 NA
10225 NA
11245 NA
12203 NA
14173 NA
15104 NA
15555 NA
20009 NA
20408 NA
87565 NA
NA - Data not reported.
167
-------
Table V-17
APPLIED FOR
DUST COLLECTION SCRUBBER
H1
£71
CO
Plant
Code.
05622
oteoi
01801
01801
09035
17018
07929
11964
03313
03313
08016
01621
01621
07228
00839
28822
03901
03313
91*12
9**12
0183*
16612
27500
Applied Flow Rate
(gallona/ 1 ^O
Applied Flou Date
{gallons/1.000 SCF)
0*621
0*621
0*621
0*621
0*621
04621
0*621
01T56
173BO
17380
07*78
07*78
07678
07678
06956
12393
16B82
11111
11111
11111
11111
11111
105
50
50
50
33
28
27
21.5
23-3
23-3
20-8
17-7
17-7
15.2
15
1*.3
11.5
to. e
to
to
8.89
B
7.5
7.2
7.1
7-1
7.1
7.1
7.1
7.1
7.T
7-06
6.71
6.71
€.7
6.7
6.7
6.7
6.67
6-67
6.<5
6-3
6-3
6-3
6.3
6.3
06956
16612
16612
03878
06956
06956
06956
18073
18073
18073
18073
18073
18073
06999
1T380
18073
18073
18073
18073
18073
18073
18073
18073
18073
1B073
18073
18073
'8073
18073
18073
18073
388*2
06956
17380
18797
18797
09706
09706
12203
06956
05*17
11111
11111
06956
17380
09706
6.25
6.16
6.12
6
6
6
6
6
6
6
6
6
6
5.95
5.89
5.8
5.8
5.8
5.8
5.8
5.8
5.8
5-8
5.8
5.8
5.8
5.8
5.8
5.8
5.8
5.B
5.8
5.77
5.71
5.T1
5.71
5.7
5.7
5.7
5.66
5.6
.6
5.6
Plant
Code
09706
17380
277*3
277«3
09706
09706
388">2
53772
53T72
27500
277*3
03313
.56
.56
5.5
14101
16612
3B842
02031
03588
0385*
05640
056 HO
056*0
056*0
056*0
056*0
06956
07228
09T06
12203
1*069
1*069
t«70
1565*
18073
18073
18073
18073
18797
23*55
23*55
38842
38842
388*2
38842
63773
63T73
Applied FJOH Sate
UOOO_SCF|
5.5
5.49
5.4
5,4
5-3
5-3
5.3
5.28
5.28
5.2
5.2
5.1«
14
14
-------
Table V-17 (Continued)
APPLIED FLOW RATES FOR
FERROUS DUST COLLECTION SCRUBBER
(Ti
'.O
Plant
Code
63773
63773
16662
17380
01756
16882
16882
166)2
14069
28822
28822
28822
58823
07162
19733
38612
38842
18797
03851
03851
27500
27500
38812
91112
1510*
11101
19*08
19108
19108
18911
19108
19108
19108
16612
16882
12393
06 72*
63773
63773
63773
Applied Flow Rate
5
5
1.99
1-93
1.88
1-78
4.76
1-76
1-73
1-7
1-7
*-7
4-7
1.6
1.6
»-5
1-5
1.11
1.1
1.1
1.1
1.1
1.1
1.1
1.38
1.36
1-31
1.31
1.31
1.29
1.29
1.29
1.29
1.26
1.26
1.21
1.2
1.2
1.2
1.2
Plant
Code
63773
63773
63773
16612
OJ756
11069
19108
13H6
13H6
13*16
13116
13116
13H6
13H6
13116
13116
13116
13116
1311*
13416
13116
13*16
13116
13116
13416
13*16
13416
13416
13416
134J6
13H6
13416
13416
13416
13M16
Applied Flow Sate
(gallona/1.000 SCF)
4.2
4.2
4.2
4.17
4.11
.14
.13
.05
Plant
Applied Flow Rate
(gallons/1.000 SCF)
13*16
13416
13416
13416
13416
13416
13416
13416
13416
13416
13416
134 1 6
13416
13416
13416
13416
13416
13416
16612
17380
18797
19408
1940S
19408
19408
03313
17380
19820
38842
38842
38812
15520
16B82
15573
17289
19408
194 OB
1940S
17380
15520
3.9T
3.9
3.9
3-9
3-9
.9
3,875
3.79
3-75
3.71
3.7
3.7
3.7
3.68
3.63
-------
Table V-17 (Continued)
•
APPLIED FLOW RATES FOR
FERROUS DUST COLLECTION SCRUBBER
Plant
Codo
18073
18073
18073
18073
18073
18073
t8073
18073
18073
18073
18073
19733-
38842
58823
58823
58823
06999
1940S
19408
19*08
19108
19108
1940S
19408
19108
19408
19*08
19408
19408
1940S
19406
140«9
15520
15520
15520
15520
15520
16892
03586
07 902
15520
15520
15520
15520
15520
Applied Flow Rat*
(gallons/1.000 SCF)
3.5f.
3.52
3.52
3-52
3-51
3-5!
3-51
3-5t
3-5
3-5
3-5
3-5
3.5
3-5
3.5
3.6
3.6
3,6
3-6
3-6
3-6
3.6
3-6
3-6
3-6
3-«
3.6
3.8
3.6
3.6
3-6
3-57
3-57
3.51
3*57
3.5T
3.57
3.5T
3-57
3-57
3.57
3.57
3.57
3.5T
3.57
3.57
Plant
15520
15520
20408
15520
15520
15520
15520
15520
16612
16612
16612
16612
16612
16612
166J2
166J2
16612
166t2
18073
18073
18073
18073
18073
18073
18073
18073
18073
18073
18073
18073
1B073
18073
t5520
15520
15520
15520
16612
16612
16612
16612
16612
16612
19*09
1940S
19408
1940S
Applied Plow Rate
1 tOOO SCF)
Plant
3.5
3.5
3,5
3.49
3,49
3.49
3.49
3.49
3.49
3.49
49
49
49
49
49
*9
49
3.49
3.49
3.49
3.49
3.«9
3.49
3.49
3.49
3.49
3-49
3.49
3-49
3.49
3.48
3.48
3.47
3.4f
3.45
3.45
3-45
3.45
3.45
3-«5
3-»5
3.45
3.45
3.45
1940S
1940S
19406
19408
16882
16882
16882
16882
16882
16882
16882
16862
07902
09035
16882
16882
16882
16882
16882
16882
16882
19733
1688?
16882
16882
04073
04073
14173
16612
16612
16612
16612
16612
16612
16612
16612
16612
16612
16612
16612
19347
19347
19408
1940S
1940S
19408
applied riOH Rat*
(gallons/I.OHO
3.45
3.45
3-45
3.45
3-43
3.43
.41
.41
.41
.41
.ill
3.4
3-4
3-4
3-4
3.1
3.4
3.4
3.4
3.4
3
3
3
38
38
34
3-33
3-33
.33
• 33
.33
•33
.33
.33
.33
.33
.33
.33
.33
.33
.33
.33
• 33
•33
•33
.33
3.33
-------
Table V-17 (Continued)
APPLIED FLOW RATES FOR
FERROUS BUST COLLECTION SCRUBBER
Plant
19408
19108
19W8
19101
$9108
19108
19*08
19*08
19W8
19*08
19408
19*08
16863
16882
16882
16882
17015
09706
16882
27500
16882
16881
03760
16082
IS 88?
16882
16882
16982
16982
16882
16862
19*08
19406
19*08
19W8
19WI
05911
07228
»9733
19733
19733
19731
Applied Flow Rote
(gallons/1.000 SCF)
3.33
3.33
3.33
3-33
3-33
3-33
3-33
3*33
3*33
3-33
.33
.33
-33
.32
•32
.32
3-32
3.31
3-3
3-3
3.3
3-2T
3-26
3.25
23
•23
23
•23
23
3-23
3-23
3.23
3.21
3-21
3-21
3-21
3-21
3-2
3.2
3.2
3-2
3.2
3.2
19733
19f33
19133
19733
19733
20009
27500
16612
16612
16612
16612
16612
16612
16612
16612
11069
16682
16882
16602
06368
16612
16612
16612
16612
16612
16612
07902
09031
H733
19733
19733
20009
20009
38842
069TT
16882
16882
16882
1686?
17318
423* «
1T331
Applied Clow Rate
(snllona/1.000 SCF)
3.2
3-2
3.2
3-2
3-2
3.2
3.2
Plant
Applied flow Rate
(gullonn/1.000 SCF)
19
19
3.19
19
19
19
.19
19
19
16
17
!?
17
13
13
>3
13
13
»3
13
1
I
t
3.1
3.1
3.1
3.08
3,06
3,06
3.06
3.06
3.05
3.05
3.04
16882
173*8
173*8
01601
01831
0183*
04DT3
0*073
OH621
04621
01621
04621
0*621
0«2t
0*621
01621
01621
0*621
04621
01621
0*621
01621
0*621
0*621
0*621
04621
0*621
04621
0*621
04621
04621
04621
0«2f
04621
01621
OH6K1
04621
01621
04621
04621
03
02
01
-------
Table V-17 (Continued)
APPLIED FLOW RATES FOR
FERROUS DUST COLLECTION SCRUBBER
Plant
Cqdo
04621
04621
04621
04621
04621
04621
04621
04621
04621
04621
04621
04621
04621
04621
09148
09148
11964
12203
14069
14809
14809
14809
14809
14809
14809
14809
14809
14809
14809
14909
14609
14809
14809
14809
14809
14909
14809
14809
14809
14809
14809
14809
14809
11909
14609
lit 809
Applied Flow Hate
.000
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
14809
11809
14809
14809
14809
11809
14809
14809
14809
14809
14809
14809
14809
14809
14809
14809
14809
11609
14809
14809
14809
14809
14809
14809
14809
14809
14809
14809
14809
14809
14809
14009
14809
14609
14809
14809
14809
14809
14809
14809
14809
14809
17348
17348
17348
17348
Applied Flo* Rate
{gallqna/1.000 SCF)
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Plant
Coda,
17348
173*8
173*8
17348
173*8
17318
1731 B
17348
173*8
173*8
193*7
277*3
38842
38842
17348
168D7
16807
173*8
173*8
17348
17348
16612
16612
16612
16(12
16612
16(12
1(082
16612
1(612
16612
16612
16612
16612
16612
16612
16612
16612
16612
16612
16082
03588
03760
05«22
08944
Applied Floy Rate
(gallons/I.000 SCF)
3
3
3
3
3
3
3
3
3
3
3
3
3
3
2.J9
2.98
2.98
2,98
2.9«
2.97
2.96
2.95
2.9*
2.94
2.93
2.93
2.93
2.93
2.92
2.J1
2.91
8.91
2.91
2.91
91
91
91
91
91
91
91
91
2.9
2.9
2.9
2.9
-------
Table V-17 (Continued)
APPLIED FLOW RATES FOR
FERROUS DUST COLLECTION SCRUBBER
Plant
Coda
OJ148
09148
23*55
Flow Rate
94412
17380
16612
16612
16612
17331
17331
06941)
16612
16612
16612
14069
07902
09035
1*635
17775
01361
12203
189*1
16941
00839
00839
025 11
16612
16612
14104
00839
03588
04621
04621
04621
07462
07172
12203
12203
14101
16612
16612
16612
16612
17370
20007
2,9
2.9
2.9
2,9
2.9
2.87
2.86
2.86
2. 96
2.81
2.81
2.8
2.78
2.78
2. 76
2.71
2,7
2,T
2-T
2.7
2.69
2.66
2.65
2.65
2.62
2.6
2,6
2.59
2.59
2.57
2.51
2.5
2.5
2.5
2,5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
?.5
2.5
2.5
Plant
Code
20784
207 81
2078«
20781
20784
20784
77775
77775
77775
77775
06999
06565
1*069
00839
16612
0175*
08482
0565 8
10865
10865
10865
10665
10865
10865
10865
10865
10865
10865
10865
10865
10865
10865
10865
10865
10S65
10865
10865
10865
10865
10865
10865
10865
10865
10865
10865
1(3665
Applied Flow Mate
.000 SCF)
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.46
2.1
2.4
2-39
2.35
2.3*
2.31
2.3
2-3
2-3
2-3
2-3
2-3
2.3
2.3
2.3
2.3
2.3
2.3
2-3
2.3
2-3
2-3
2.3
2.3
2.3
2-3
2.3
2,3
2.3
2.3
2-3
2.3
2.3
2.3
2-3
FlMlt
10865
10865
10865
10665
10865
10865
10865
20007
01381
08462
17331
17331
20249
20249
20299
20249
2021(9
20249
20249
20249
20249
20249
20259
20299
20249
20249
20249
202H9
20249
20249
202*9
20249
20249
202^9
20249
15372
06124
07839
38892
05658
19347
193*7
19317
20699
20699
Applied Flow Kate
.000 SCfJ
2-3
2-3
2.3
2-3
2.3
2.3
2-3
2.3
2.25
2.25
2.25
2.25
2.2
2.2
2.2
2.2
2.2
2.2
2.2
2.2
2.2
2.2
2.2
2.2
2.2
2,2
2.2
2.2
2.2
2.2
2.2
2.2
2.2
2.2
2.2
17
1
1
r
-------
Table V-17 (Continued)
APPLIED FLOW RATES FOR
FERROUS DUST COLLECTION SCRUBBER
Plant
20699
20699
01381
03901
03901
03901
03901
03901
0183ft
20007
06999
15372
01381
01381
01381
07172
15101
15101
19533
Applied Flow Rate
(K«llona/1tOppi
06999
01381
01381
036*6
01292
11635
11635
11635
94412
19933
05006
1H173
11173
06999
17289
11173
06121
07929
079?9
07929
07929
07929
07929
07929
07929
17289
2
2
1.97
1.96
t.96
1.96
1.96
1.96
1.9
1-9
1.88
1.875
1.87
1.79
1-79
1.7
f-63
1.6
1.6
1.6
1.58
1.56
1.5
1.5
1,»5
1.1
1.1
1.1
1.1
1-3
1.25
1.25
.25
,11
.12
.11
.1
.1
.1
.1
.1
.1
1.1
1.1
1.1
1.1
Plant
Code
18919
16502
05008
01835
08868
08806
06868
OB 86 8
08868
13578
1T331
17230
07902
17230
17230
17230
01381
02195
09021
20009
20009
20009
27713
27713
277*3
27713
277U
71991
7*991
13578
27713
13578
20009
08016
11173
06121
20112
71991
00015
20112
09111
07902
18919
18919
01756
01756
Applied Flo* Rate
(gal long/ IjOOO
1,1
09
04
03
1
1
t
1
1
1
1
1
1
1
0.91
0.89
O.BJ
O.BT
0.87
0,83
0.83
0.8
0.?7
O.T7
0.77
0.75
0.75
0.75
0.75
0.75
0.75
0.75
0.73
0.71
0.7.
0.68
0.67
0.67
0,66
0.65
b.61
0.63
0.62
0.6
0.57
0.56
0.56
0.55
0.5*
Flanl
Coda
OJ756
16502
00015
02883
OT29«
07*62
11173
03760
00388
00388
08016
16502
20009
02683
07298
08016
08016
08518
OT322
07863
20009
00396
03851
070211
07298
08070
20009
09929
20009
20699
20009
07021
20699
20009
03760
07021
07021
07021
11865
28188
0565 B
03760
20699
68281
DOT 91
Applied Flov Rate
(gallons/liOOO SCF)
0.51
0,53
.5
.5
.5
.5
.5
.19
.IB
.*8
0.
0,
0.
0,
0.
0.
0.
0,
0.
0,
0.»8
0.«5
0.11
O.i? 1
0.11
0.11
0.13
0.39
0.38
0.36
O.J6
0.33
0.33
0.33
0.33
0.32
0.32
0.32
0.31
0.28
0.28
0.27
25
25
25
25
25
25
2*
0.22
0,21
0.21
0.21
0.2
-------
Table V-17 (Continued)
APPLIED FLOW RATES FOR
FERROUS DUST COLLECTION SCRUBBER
Plant
Coda
03432
05622
14761
05333
085 IB
11761
17018
03432
11865
11761
06516
06123
71991
06123
06123
06123
06123
06123
06123
06123
06123
06123
06123
06285
03878
03878
03049
Applied Flow Kate
.000 BCF)
Plant
03913
03913
0851 6
0.2
o.ig
0.19
0.17
0.17
0.15
0.15
0,11
0.14
0.11
0.138
0.136
0.13
0.126
0.125
0.125
0.125
O.J25
0.125
0.125
0.125
0.125
0.125
0.125
0.12
0.12
0.11
0.11
0.11
0.11
0,1
20206
20208
03*32
08518
03*32
13*60
21566
7*991
08518
11197
18882
21566
08518
7*991
03118
11197
21566
085 IB
08518
74991
056*3
06773
11197
20011
74991
20208
04688
05643
11598
13460
20208
Ippiled Flo* Rate
(galIona/1.000 SCT)
0.1
0.1
0.095
0.093
0.068
0.088
0.083
0.083
0.082
0.08
O.OB
0.071
0,066
0.063
0.06
0.06
0.057
0.051
0,054
0.053
0.05
0.05
0.05
0.05
0.05
0.045
0,04
0.04
O.OJ5
0.033
0.033
Plant
Code
20205
022*3
073**
11598
20208
2*566
ooeeo
11197
1216H
02365
02365
05643
13460
(2314
04100
05912
13460
00696
00698
01953
02236
15873
0 D100
423*4
11598
11598
13460
13460
08436
08436
Applied Flow Rate
(galIons/1.000 SCFJ
0.033
0.03
0.03
0,026
0.026
0.026
0,02
0.02
0.02
0.015
0.015
0.015
0.015
0.013
0.011
0.011
0.011
0,01
0.01
0.01
0,01
0.01
0.008
0.006
0.0056
0.005
0.004
0.004
0.000**
0.00036
-------
Table V-18
APPLIED FLOW RATES FOR
FERROUS GRINDING SCRUBBER
Applied Flow Rate
Plant Code (gallons/1rQOQ SCF)
07438 78.26
11964 18
94412 10
94412 10
04621 7.14
04621 6.52
63773 5
63773 5
63773 5
19733 4.64
94412 4.4
13416 4,34
19733 4.1
13416 4
13416 4
13416 4
13416 4
13416 4
13416 4
19733 3.57
19733 3.57
15520 3.5
16612 3.49
16612 3.49
20249 3.49
15520 3.48
15520 3.48
16612 3.45
16612 3.^5
16882 3.4
16882 3.4
16612 3.33
16612 3.33
16612 3.33
16612 3.33
16882 3.26
16612 3.19
16612 3.19
04621 3.15
16612 3.12
16612 3.12
176
-------
Table V-18 (Continued)
APPLIED FLOW FOR
FERROUS GRINDING SCRUBBER
Applied Flow Rate
Plant Code fgallons/1,OOP SCF)
04621 3
04621 3
04621 3
04621 3
14809 3
14809 3
17348 3
16612 2.91
16612 2.91
16612 2.91
16612 2.91
16612 2,86
10865 2,35
10865 2,34
19347 2
19347 2
19347 2
03898 1.83
14173 1.25
00396 0.67
03049 0.56
18919 0.56
06123 0.25
07024 0.25
05167 0.17
06123 0.12
06123 0,12
06123 0.12
03^32 o.i
03432 0.08
08518 0.07
08518 0,05
08518 0.05
10600 0,03
00891 0,006
177
-------
Table V-19
APPLIED FLOW RATES FOR
FERROUS MELTING FURNACE SCRUBBER
Applied Flow Rate
Plant Code fgallons/IrOOO SCF)
07170 125
07438 78.3
01942 71.43
05584 60
04621 41.7
04621 41.7
04621 41.7
04621 41,7
03913 41.4
03898 41.2
16502 36
04632 30.8
04577 29.4
58823 28.7
14670 27,8
13416 27,3
13416 27.3
13416 27.3
20345 27
17230 26.1
15555 25.5
05533 25
28822 24
09183 21.5
03646 20
09024 19.6
23455 17.8
23455 17.8
07472 17.4
19820 16.7
05533 16.7
01381 16.2
10684 15.9
19820 15.4
19408 15
19408 15
06343 13.64
16612 12.5
16612 12.5
03901 12.5
01801 11,3
178
-------
Table V-19 (Continued)
APPLIED FLOW RATES F01
FER10US MELTING FURNACE SCRUBBER
Applied Flow Rate
Plant Code fgallons/1rQOQSCF)
16612 11.1
14254 11
08496 10
16612 10
16612 10
14809 9.84
14809 9.84
02236 9,8
14809 9.75
18073 9.75
18073 9.75
18073 9.75
18073 9.75
14254 9.7
14254 9,7
14809 9.68
09035 9.53
14809 9.43
14809 9.43
05008 9.3
14809 9.27
14809 8.65
10865 8.33
10865 8.33
10865 8.33
02121 8.3
18073 8.3
18073 8.3
06426 7.5
7,3
03313 7
14809 6,78
12393 6.67
07678 6,4
14809 6.02
08944 5.9
23454 5.8
14809 4.5
13416 4
13416 4
08944 2.8
179
-------
Table V-19 (Continued)
APPLIED FLOW RATES FOR
FERROUS MELTING FURNACE SCRUBBER
Applied Flow Rate
Plant Code fgallons/1.000 SCF>
08092 2.3'
53772 1.5
03383 1.25
00000 1
00001 NA
00002 NA
00396 NA
007^9 NA
01064 NA
01635 NA
02031 NA
02195 NA
02418 NA
03399 NA
03868 NA
04955 NA
05640 NA
05642 NA
05658 NA
05691 NA
06265 NA
06956 NA
07225 NA
07524 NA
08016 NA
08301 NA
08663 NA
08828 NA
09151 NA
09441 NA
09593 NA
09706 NA
09925 NA
11964 NA
14069 NA
15520 NA
17746 NA
19347 NA
19533 NA
20249 NA
28821 NA
180
-------
Table V-19 (Continued)
APPLIED FLOW RATES FOR
FERROUS MELTING FURNACE SCRUBBER
Applied Flow Rate
Plant Code (yallona/lfOOP SCF)
50000 NA
52491 NA
53219 NA
56789 NA
57775 NA
58589 NA
63773 NA
74991 NA
77775 NA
80002 NA
80122 NA
80788 NA
82921 NA
83075 NA
83810 NA
85100 NA
85909 NA
86100 NA
86956 NA
89934 NA
94412 NA
14173 NA
14444 NA
30160 NA
80116 NA
88281 NA
89933 NA
NA - Data not reported,
181
-------
Table V-20
APPLIED FLOW RATES FOE
FERROUS HOLD COOLING
Applied Flow Rate
Plant Code Cgallon?/fron)
18947 9,434
15654 5,550
14580 4,377
08944 1,376
17746 986
14069 426.8
11865 304
14444 201
15555 190
55
00388 NA
14173 NA
15104 NA
17018 NA
HA - Data not reported.
182
-------
Table V-21
APPLIED FLOW RATES FOR
FERROUS SLAG QUENCH
Applied Flow Rate
P.^ant Code (gallons/ton)
83810 64,000
58823 7,192
19533 6,558.7
10684 5,731
13416 4,235
82277 3,876
01756 3,231
06213 3,173
28822 3,086
28821 2,788
05533 2,713
10865 2,368
05691 2,280
17380 2,251
16612 2,247
09441 2,216
14809 2,038
04621 1,943
85909 1,693
27500 1,652
02195 1,650
08518 1,589
19347 1,500
09706 1,441
74991 1,397
01942 1,287
03901 1,201
15520 ;,176
04688 1,162
03646 1,007
15555 997
24595 935
11964 925
14069 880
02121 873
50000 810
14173 805
18919 777
23455 753
16666 727
2078,4 646
17746 632
183
-------
Table V-21 (Continued)
APPLIED FLOW RATES FOR
FERROUS SLAG QUENCH
Applied Flow Bate
Plant Code (gallons/top)
11865 60?
1940S 575
19343 571
14444 540
80002 524
83075 491
03313 436
415
10388 414.3
19820 400
05538 378,9
07678 330
17348 327
06123 324
20112 304
06956 302
20345 300
285
02031 274
94412 262
06773 259
07322 256
1894? 236
00749 183
02365 180
17018 179
01381 162.7
87.3
47-3
13089 47.1
08663 38.7
01635 37.5
01801 28
02236 16.7
08070 16
04577 7.14
05658 2,4
04073 KA
04222 NA
06565 NA
20249 NA
184
-------
Table V-21 (Continued)
APPLIED FLOW RATES FOR
FERROUS SLAG QUENCH
Applied Flow Rate
Code C al Ions/ ton)
277^3 NA
30160 NA
53772 NA
63773 NA
89933 NA
8993^ NA
NA - Data not reported,
185
-------
Table V-22
APPLIED FLOW RATES FOR
FERROUS WET SAND RECLAMATION
Applied Flow Rate
lant. Code
11964 3,085
17348 3,040
17380 2,808
20009 1,565
24566 1,518
20699 --1,402
80770 916
51473 873
07024 686
20007 465
14173 234
51115 213
15520 198
13089 59
01381 NA
07902 NA
NA - Data not reported.
186
-------
Table V-23
APPLIED FLOW RATES FOR
MAGNESIUM CASTING QUENCH
Applied Flow Rate
Plant Code Cgallons/ton)
07414 NA
08919 NA
NA - Data not reported.
Table V-24
APPLIED FLOW RATES FOR
MAGNESIUM DUST COLLECTION SCRUBBER
Applied Flow Rate
Plant Code (gallons/1rOOQ SCF)
08146 0.5
08146 0.05
Table V-25
APPLIED FLOW RATES FOR
MAGNESIUM GRINDING SCRUBBER
Applied Flow Rate
Plant Code (yallons/1rQQO SCF)
05244 NA
NA - Data not reported.
187
-------
Table V-26
APPLIED FLOW RATES FOB
ZINC CASTING QUENCH
Applied Flow Rate
al 1 Q t / 1 on __
29434 40,632
05117 7,259
01385 6,598
02589 4,096
01334 4,000
18463 2,152
29697 880
10640 857
21207 772
18139 591
05091 533
84469 458
01707 320
83713 245
04622 147
18047 144
85550 92,7
13524 66.7
12-060 32.7
10308 28,1
08724 5.5
04525 NA
04839 NA
05739 NA
05947 NA
06606 NA
09 1 05 NA
09707 NA
10475 NA
15506 NA
81150 NA
NA - Data not reported.
188
-------
Table V-27
APPLIED FLOW RATES FOR
ZINC DIE CASTING
Applied Flow Rate
Plapfc Coda fgallona/ton)
18139 41.4
84469 28.6
64994 22.6
04622 9.4
83713 3.33
82111 (1)
05117 NA
06606 NA
08724 NA
09105 NA
09707 NA
10308 NA
10475 NA
10640 NA
12060 NA
13524 NA
18047 NA
29434 NA
29697 NA
80120 NA
82111 NA
(1) Die castingi mold cooling, casting quench wastewater
reported together.
NA - Data not reported.
189
-------
Table V-28
APPLIED FLOW RATES FOR
ZINC MELTING FURNACE SCRUBBER
Applied Flow Rate
Plant Code (gallons/1rQOO SCF)
10640 24
18139 9-38
18139 9.38
18139 6.0?
18139 6.07
13524 0.81
13524 0.81
10475 0.38
18047 0.38
04622 0.33
13524 0.27
13524 0.27
13524 0.25
13524 0.25
18047 0.24
Table V-29
APPLIED FLOW RATES FOR
ZINC MOLD COOLING
Applied Flow Rate
Plant Code Cjal^ons/ton)
04622 4,860
02589 4,100
01334 4,000
10640 1,890
05947 685
18139 230
09105 42.7
80120 NA
01707 NA
21207 NA
NA - Data not reported
190
-------
Table V-30
METAL MOLDIHG AMD CASTING
ANALYTICAL DATA SUMMARY
Aluainua Casting Quenoh - Raw Hastewater
Pollutant
004 Benzene
015 1,1,2,2-Tetraehloroethane
021 2,4,6-Triohlorophenol
022 Parachlorooetacresol
023 Chloroform
034 2,4-Di»ethylphenol
036 Ethylbenzene
039 Fluoranthene
044 Methylene chloride
057 2-Hitrophenol
059 2,4-Dinltrophenol
060 4,6-Dinitro-o-cresol
065 Phenol
066 Bis(2-ethyl hexyl)phthalate
067 Butyl benzyl phthalate
071 Dimethyl phthalate
077 Aoenaphthalene
084 Pyrene
065 Tetraohloroethylene
087 Trichloroethylene
115 Arsenic
120 Copper
122 Lead
124 Nickel
Sumber of
Samples
Analyzed
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
1
3
4
3
Number of
Tines
Detected at
Quantifiable
Levels
2
1
2
1
1
2
1
2
3
1
1
1
3
k
3
1
1
3
3
3
1
3
1
1
Concentration
Ramie (%/!)
0.0 - 0.02
0.013
0.3 - 0.58
0.925
0.0 - 0.035
0.05 - 0.13
0.0 - 0.033
0.0 - 0.43
0.012 - 0.027
0.038
0.41
0.285
0.038 - 0.072
0.013 - 0.54
0.04 - 0.082
0.035
0.0 - 0.14
0.0 - 0.5
0.099 ^ 0.255
0.0 - 0.022
0.01
0.07 - 0.3
0.0 - 0.44
0.0 - 0.04
Average
Cone ent ration
(«*/!> 1
0.009
0.013
0.044
0.925
0.009
0.09
0.011
0.215
0.018
0.038
0.41
0.285
0.051
0.173
0.063
0.035
0.07
0,199
0.161
0.012
0.01
0.187
0.11
0.013
Average
Loed
tag/kkg)*
0.659
1.52
23.4
18. «
1.03
1.78
1.29
4.27
1.23
4.46
8.14
5.66
1.00
5.26
2.56
H.11
1.39
3.94
6.42
0.605
0.200
5.98
12.9
1.57
-------
Table V-30 (Continued)
METAL MOLDING AND CASTING
ANALYTICAL DATA SUMMARY
Aluminum Casting Quench - Raw Wastewater
Pollutant
128 Zinc
Aluminum
Iron
Manganese
Oil & Grease
Phenols (4AAP)
Suspended Solids
Number of
Samples
Analyzed
4
4
1
4
4
4
4
Number of
Times
Detected at
Quantifiable
Levels
4
4
1
4
4
4
4
Average Average
Concentration Concentration Load
(ag/1) f«/l) 1
0.15 - 9.1
0.9 - 5.3
4.7
0.07 - 0.56
103 - 182
0.036 - 0.156
58 - 1,307
2.49 271
2.35 176
4.7 551
0.093 17.8
151 6,390
0.081 3.14
720 15,700
Straight average of available analytical data. Concentrations have not been normalized to account
for flow rates and degree of recycle at sampled plants.
"Normalized mass of pollutant generated per unit of production.
-------
fable V-31
METAL MOLDING AND CASTING
ANALIT 1CAL DATA SUHHABY
Aluminum Die Coating - Raw Waatewater
Pollutant
001 Aoenapbtbene
004 Benzene
005 Benzidlne
006 Carbon tetrachlorlde
007 Chlorobenzene
010 1,2-Diobloroethane
Oil 1,1,1-Triobloroethane
013 1,1-Diohloroethafle
015 1,1,2,2-Tetrachloroethane
Oil Ma (2-ch lore ethyl) ether
Oil 1,4,6-Triohloropbenol
021 Paracbloronetacreaol
023 Chlorofora
024 2-Cblorophenol
031 2,4-DiQfalorophanol
03^ 2,4-Dimethylphenol
039 Fluoranthene
044 Hatbylene chloride
018 DiohlorobroBonethane
055 Naphthalene
05? 2-Hitrophenol
058 4-Nltrophenol
062 M-HitroBodiphenol
063 H-Mitroaodl-n-propylaiilae
064 Pantaoblorophenol
Nunber of
Samples
Analyzed
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
14
11
14
14
14
14
Number of
Times
Detected at
Quantifiable
Levels
3
5
1
2
4
1
5
1
1
1
5
4
10
2
2
4
3
13
2
5
1
1
1
2
1
Concentration
Range (HK/!)
0.054 - 0.38
0.0 - 0.555
7.6
0.0 - 1.40
0.013 - 1.6
0.520
0.0 -37
0.165
0.010
0.024
0.015 - 2,0
0.068 - 0.150
0.0 - 1.3
0.0 - 0.235
0,0 - 0.150
0.0 - 0.120
0.0 - 16
0.003 -6.2
0.012 - 0.017
0.063 - 7.9
1.00
0.45
0.620
0.022 - 0.078
4.80
Average
Concentration.
(•*/!) '
0.221
0.100
7.6
0.287
0.590
0.520
11.01
0.165
0.010
0.024
0.631
0.105
0.31
0.083
0.073
0.033
3.46
1.224
0.0145
1.7
1.00
0.45
0.620
0.050
4.80
Average
miAfl&M M
(qg/kte)
566
24.4
635"
26.2
127
76
1720
24.2
55.6
133
1630
569
202
317
350
217
1320
316
25.4
523
5080
37.6
90.7
278
798
-------
Table V-31 (Continued)
METAL MOLDIKG AND CASTING
ANALYTICAL DATA SUtURX
Alualoum Die Casting - Raw Haatewater
Pollutant
Aluninun
Amonla
Iron
Manganese
Oil & Grease
Phenols (4AAP)
Suspended Solids
Nuober of
Samples
Analyzed
14
11
11
14
14
14
14
Number of
Times
Detected at
Quantifiable
Levels
11
8
11
10
14
14
11
Concentration
Range Cag/1)
0,8 - 34
0.0 - 29
0.90 - 19
0.0 - 0.29
48 - 49,900
0.057 - 125
63 - 3,576
Average
Concentration
(Bg/1)
6.7
1
Average
Load
.5
.7
10.
56,
0.07
6,264
30.17
918
1 1 ,600
2,430
15,200
257
3,280,000
9,860
1,580,000
i .
Straight average of available analytical data. Concentrations have not been normalized to account
for flow ratas and degree of recycle at aanpled plants.
2
formalized aass of pollutant generated per unit of production.
•Average load la not available.
-------
Table V-32
METAL HOLDING AND CASTING
ANALYTICAL DATA SUMMARY
Aluminum Investment Casting - Haw Wastewater
Pollutant
006 Carbon tetraotaloride
010 1,2-Diobloroethane
011 1,1,1-Tricbloroetbane
023 Chloroform
024 2-Cblorophenol
034 2,4-Dimethylphenol
044 Metbylene chloride
055 naphthalene
066 Bis(2-ethyl hexyl)phthalate
073 Benzo(a)pyrene
077 Acenaphthalene
084 Pyrene
085 Tetraohloroethylene
087 Triehioroethylene
106-108 PCB 1242, 1254, 1221
109-112 PCS 1232, 1248, 1260, 1016
119 Chromium
120 Copper
122 Lead
124 Nickel
128 Zlno
Number of
Samples
Analyzed1
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Number of
Times
Detected at
Quantifiable
Levels
1
1
3
3
1
1
3
1
3
1
1
1
3
3
2
3
2
3
2
2
3
Concentration
Raiuse (BIK/I)
0.0 - 0.083
0.0 - 0.005
0.008 - 0.367
0.037 - 0.090
0.007
0.008
0.012 - 0.097
0.006
0.020 - 0.021
0.008
0.031
0.086
0.061 - 0.149
0.035 - 0.087
0.0 - 0.011
0.002 - 0.026
0.0 - 0.041
0.071 - 1.12
0.0 - 0.098
0.0 - 0.012
0.16 - 1.20
Average
Concentration
(ms/1)
0.028
0.003
0.138
0.056
0.007
0.008
0.041
0.006
0.020
0.008
0.031
0.086
0.104
0.067
0.004
0.011
0.017
0.482
0.036
0.006
0.53
Average
Load
(mg/kkg)3
595
58.7
2,970
1,210
15«
176
889
132
433
176
668
1,850
2,250
1,430
•
»
367
10,400
764
125
11,400
-------
Table V-32 (Continued)
METAL MOLDIHG AMD CASTING
ANALYTICAL DATA SOQURI
Aluminum Investment Casting - flaw Vaatemter
Pollutant
Aluminum
Iron
Manganese
Oil & Grease
Suspended Solids
Number of
Samples
Analyzed
3
3
3
3
3
Number of
Times
Detected at
Quantifiable
Levels
3
3
3
3
3
Conoentrat ion
$ange (ae/1)
0.94 - 4.33
2,04 - 4.18
0,033 - 0.056
20 - 32
590 - 1,398
Average Average
Concentration Load
(•K/l) 2 Cn^/kteJ3
2.19 47,600
2.82 60,700
0.046 984
26 569,000
933 20,100,000
Three sampling days data were available for plant 01704. Investment casting data are a flov
weighted average of data for sample point B, D, and E for each day.
2
Straight average of available analytical data. Concentrations have not been normalized to account
for flow rates and degree of recycle at sampled plants.
Normalized mass of pollutant generated per unit of production.
•Average load is not available.
-------
fable V-33
KETAL HOLDING AND CASTING
ANALYTICAL DATA
Aluminum Melting Furnace Scrubber - law Wastewater
Pollutant
001 Acenapbthene
021 2,4,6-Triehlorophenol
023 Chloroform
031 2,4-Diohlorophenol
031 2,4-Dinethylphenol
039 Fluoranthene
0^ Hethylene chloride
065 Phenol
066 Bis(2-ethyl hexyl)phthalate
06S Di-n-butyl phthalate
070 Blethyl phthalat*
073 Benzo(a)pyrene
08ft Pyrene
120 Copper
126 Zlno
Aluminum
Ammonia
Manganese
Oil & Grease
Phenols (4AAP)
Suspended Solids
Number of
Samples
Analyzed _
6
6
6
6
6
6
6
6
6
6
6
6
6
3
6
6
6
6
6
6
6
Number of
Times
Detected at
Quantifiable
Levels
4
6
1
1
2
2
3
6
2
2
2
1
3
6
6
3
5
6
6
6
Cone en t ra t ion
Hange (mg/1)
Average
Concentration
(gg/1)
Average
(mg/tOOOm3)2
0.0 -
0.0 -
0.015
0.0 -
0.0 -
0.0 -
0.0 -
0.0 -
.03 -
.0 -
.0 -
0.025
0.0 -
0.04 -
.04 -
,1 -
.0 -
.0 -
2-16
0.002
2-53
0,
0.
0,
0,
0,
0,
0.
0.023
0.235
- 0.098
0.018
0.023
0.023
0.031
0.023
0.320
0.110
0.044
- 0.084
0.029
0.20
0.30
5.8
0.6
0.06
- 1.28
0.012
0.073
0.05
0,004
0,006
0,007
0.01*
O.OOf
0.14
0.023
0.020
0.054
0.007
0.1
0.2
2.6
0.2
0.04
8
0.44
29
1.75
51.1
2.96
1,88
7.19
9.65
0.844
1.74
126
25.4
10
8.3
7.55
113
73.6
3,510
45.7
20.3
6,660
413
32,200
Straight average of available analytical data* Concentrations have not been normalized to account
for flow rates and degree of recycle at saopled plants.
"Normalized mass of pollutant generated p«r unit of product ion.
-------
Table ¥-3*
METAL MOLDING AND CASTING
ANALYTICAL DATA SUMMARY
Copper Direct Chill Casting - Raw Vastewater
10
00
Pollutant
120 Copper
122 Lead
124 Nickel
126 Zino
Aluminum
Iron
Manganese
Oil 4 Grease
Suspended Solids
Number of
Samples
Analyzed
3
3
3
3
3
3
3
3
3
Number of
Tinea
Detected at
Quantifiable
Levels
3
3
3
3
3
3
3
3
3
Cone eat rat ion
Range (mg/1)
11.9 - 32.0
0,10 - 0.20
0.15 - 2.35
4.38 - 7.18
0.40 - 0.50
1.35 - 3.05
0.05 - 0.10
11-40
78 - 125
Average
Concentration..
(aw/I) 1
29.3
0.15
1.07
5.91
0.43
1.95
0.08
21
99
Average
Load
(mg/kkgr
58,400
289
2,120
1 1 ,700
844
3,860
164
41 ,000
197,000
1
Straight average of available analytical data. Concentrations have not been normalized to account
for flov rates and degree of recycle at sampled plants.
i
'Normalized mass of pollutant generated per unit of production.
-------
Table 7-35
METAL HOLDING AND CASTIHO
ANALYTICAL DATA SOMKART
Copper Dust Collection Scrubber - Raw Vastcrater
Pollutant
001 Aoenaphtbene
021 2,4,6-Trlobloropbenol
022 Paraohloroaetacreaol
023 Chloroform
034 2,4-Dl»ethylphenol
036 2,6-Dlnltrotoluene
055 naphthalene
057 2-Hitrophenol
056 4-Hitrophenol
064 Pentachlorophenol
065 Phenol
066 Bis{2-ethyl h«yl)phthalate
067 Butyl beniyl phthalate
068 Dl-n-butyl pbtbalate
069 Di-n-oetyl pbtbalate
070 Dietbyl pbtbalate
071 Dimethyl pbtbalate
072 Benzo{a)anthracene
073 Benzo(a)pyrene
074 3,4-Bensofluorantbene
075 Denzo(k)fluoranthene
076 Chryaen*
077 Acenaphtbalene
078 Anthraoene
Kuaber of
Sanplea
Analyzed
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
Number of
Tiaes
Detected at
Quantifiable
Levels
2
1 *
2
1
3
1
2
1
2
3
5
6
5
5
1
2
2
2,
1
2
2
4
2
5
Average
Concentration Concentration,
0,0 - 0.2
0.0 - 0.024
0,0 - 0,044
0.0 - 0.023
0.0 - 0.142
0.02
0.0 - 0.025
0.0 - 0.079
0.0 - 0.033
0.0 - 0.116
0.0 - 0.17
0,0 - 1.6
0.01 •* 0.71
0.0 - 0.22
0.0 - 2
0.0 - 0.025
0,036 - 0.231
0.084 - 0,095
0.065
0,03 - 0.162
0.006 - 0.011
0.006 - 0.011
0.0 - 0.022
0.0 - 0.2«
0.057
0.006
0.011
0.004
0.035
0.02
0.007
0.040
0.016
0.026
0.051
0.253
0.27
0.042
1.0
0.013
0.134
0.090
0.065
0.009
0.009
0.093
0.011
0.049
Average
Load
r100Qg-
1.72
0.5T3
0.126
.16
.44
.15
5.
3<
1
4.01
1.15
4.59
5.16
45.9
2.29
*
2.29
22.4
15.5
10.9
1.15
1.15
16.06
1.72
2.87
-------
Table V-35 (Continued)
METAL MOLDING AMD CASTING
ANALYTICAL DATA SUMMARY
Copper Dust Collection Scrubber - Ban Waatewater
Pollutant
081 Phenanthrene
084 Pyrene
115 Arsenic
118 Cadmium
119 Chromium
120 Copper
122 Lead
124 nickel
126 Silver
128 Zinc
Aluminum
Iron
Manganese
Oil & Grease
Phenols (4AAP)
Suspended Solids
Number of
Samples
Analyzed
7
7
4
5
5
5
7
5
4
7
7
1
7
7
7
7
Number of
Times
Detected at
Quantifiable
Levels
5
5
4
5
5
5
7
5
4
7
7
1
7
7
7
7
Concentration
Range (mg/1)
0.0 - 0.24
0.0 - 0.044
0.01 - 0.03
0.01 - 1.2
0.03 - 1.2
1.1 - 250
2.1 - 53
0.04 - 3.1
0.02
7.5 - 1,200
4.8 - 770
750
0.16 - 11
2-55
0.165 - 3.27
316 - 35,000
Average
Concentration
(UK/I)
0.049
0.022
0.018
0.322
0.264
83.3
22.5
1.14
0.02
269.1
132
750
2.28
17
2.12
5,524
Average
. Load
(mK/1000 nr)
2.87
3.44
2.87
17.2
5.16
15,200
3,960
109
3.H4
19,150
4,240
•
139
1,800
350
105,000
Straight average of available analytical data. Concentrations have not been normalized to account
for flow rates and degree of recycle at sampled plants.
Normalized mass of pollutant generated per unit of production.
•Average load is not available.
-------
Table V-36
METAL HOLDING AHD CASTING
ANALYTICAL DATA SUMMARY
Copper Hold Cooling - Raw Wasterater
CO
o
Pollutant
006 Carbon tetraohloride
011 1,1,1-Trichloroethane
014 1|1,2-Trlohloroethane
023 Chloroform
045 Methyl chloride
064 Pentachloropheool
066 Bl6<2-etbyl heryDphthalete
071 Dimethyl phthalate
085 Tetraohloroethylene
087 Triohloroethylene
118 Cadmium
120 Copper
122 Lead
128 Zino
Aluminum
Manganese
Oil & Grease
Phenols (4AAP)
Suspended Solids
Number of
Samples
Analyzed
4
4
4
4
4
4
4
4
4
4
3
3
4
4
4
4
4
4
4
Dumber of
Times
Detected at
Quantifiable
Levels
1
1
1
1
1
1
4
1
1
1
3
3
4
4
4
4
4
4
4
Concent ratIon
Range (mg/1)
0.032
0.014
0.013
0.0 -
0.028
0.051
0.016
0.093
- 0.15
0.0 - 0.036
0.280
0.180
0.01 - 0.13
0.27 - 1.1
0.05 - 0.89
1.9 - 3-5
0.2 - 0.9
0.07 - 0.12
1 - 110
0.003 - 0.012
16 - 82
Average
Concentration,
(UK/1) ^
0.032
0.140
0.013
0.023
0.028
0.051
0.071
0.018
0.280
0.180
0.077
0.61
0.26
2.45
0.45
0.07
34
0.006
46
Average
1 Load ;
24.5
106
10.2
23.5
21.5
38.8
67.5
13.3
212
136
82.8
272
37.8
1,590
227
65.4
33 t 800
5.11
42,400
1
Straight average of available analytical data. Concentrations bave not been normalized to account
for flow rates and degree of recycle at sampled plants.
"Normalized mass of pollutant generated per unit of production.
-------
Table ¥-37
METAL MOLDING AND CASTING
ANALYTICAL DATA SOWAR*
Ferrous Casting Cleaning - Ban Vesteweter
K(
C!
SJ
Pollutant
11* AntUKmy
118 Cadaiu*
119 Cbronlun
124 Nickel
126 Silver
128 Zinc
Cobalt
Iron
Manganese
Oil & Grease
Phenol (4AAf)
Suspended Solids
Number of
Samples
Analyzed
3
3
3
3
3
3
3
3
3
2
3
3
Number of
Tines
Detected at
Quantifiable
Levels
2
3
3
3
3
3
3
3
3
2
3
3
Concentration
Range («g/l)
0.0 - 0.12
0.92 - 1.1
0.046 - 0.068
61 - 72
0.0175 - 0.024
0.16 - 0.64
0.10 - 0.11
6.1 - 19
2.9 - 3.2
7.1 - 9.8
0.041 - 0.11
10 - 54
Average
Concentration.
(BK/1) '
0.07
1.0
. 0.057
66
0.022
0.36
0.11
11.6
3.1
8.4
0.066
28
Average
Load
(fflg/klut)2
11.0
151
8.61
9,950
3-23
54. f
16.0
1,740
461
1,270
9.85
4,310
1
Straight average of available analytical data. Concentrations nave not been normalized to account
for flov rates and degree of recycle at samplad plants.
NonMlizad mas a of pollutant generated per unit of prod uot ion.
-------
Table V-38
MlfAL MOLDING AND CASTING
AMALITICAL DATA
Ferrous Casting Quench - Raw Wasteaater
Pollutant
004 Benzene
023 Chloroform
034 2,4-Dimethylphenol
120 Copper
122 Lead
124 Nickel
128 Zinc
Aluminum
Iron
Manganese
Suspended Solids
Number of
Samples
Analyzed
1
1
1
6
6
6
6
6
6
4
6
Number of
Times
Detected at
Quantifiable
Levels
1
1
1
6
1
5
5
4
6
H
6
Concentration
Banite (mg/1)
0.002
0.032
0.021
0.001 - 0.24
0.0 - 0.05
0.0 - 0-12
0.0 - 0.05
0.079 - 0.5
1.1 - 42
0.059 - 0.9
16-36
Average
Concen t ra t ion
(OK/I)
0,002
0.032
0.021
0.16
0.008
0.056
0.020
0.28
15
0,28
29
Average
Load
(mg/kke)2
3.57
58.6
38.4
182
19-8
132
47.4
586
35,200
628
61,800
1
Straight average of available analytical data. Concentrations have not been normalized to account
for flow rates and degree of recycle at sampled plants.
>
"Normalized mass of pollutant generated per unit of production.
-------
Table ¥-39
METAL HOLDING AND CASTING
ANALYTICAL DATA SDWiARI
Ferrous Dust Collection Scrubber - Raw Vastevater
Pollutant
001 Aeenaphthene
011 1,1,1-Triohloroethane
020 2-Chloronaphthalene
022 ParachloroMtacresol
023 Chloroform
024 2-Chlorophenol
031 2,4-Diohlorophenol
034 2,4-Dl»sthylphenol
035 2,ft-Dlnitrotoluene
036 2,6-DiBltrotoluene
039 Fluoranthene
043 Bla(2-ohloroethoxy)»ethane
044 Hethylene ohlorIde
054 Isopborone
055 Naphthalene
056 Nitrobenzene
057 2-Jlltropbenol
058 4-Bltrophenol
062 K-NltroBodlphenol
064 Pentaohlorophenol
065 Phenol
066 Bia(2-ethyl heoeyl) phthalate
067 Butyl benzyl phthalate
068 Di-n-butyl phthalate
069 Dl-n-ootyl phthalate
Niuber of.
Samples
Analyzed
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
32
Nuaber of
Tines
Detected at
Quantifiable
Levels
12
2
1
3
14
3
15
17
1
1
20
2
ie
4
11
i
4
2
3
19
24
26
11
24
2
Cone en t rat ion
Range (tnK/1)
0.0 - 0.07
0.0 - 0.075
0.01
0.0 - 0.2
0.0 - 0.078
0.0 - 0.23
0,0 - 1.4
0.0 - 1.2
0.0 - 0.095
0.0 - 0.095
0.0 - 0.073
0.0 - 0.045
0.0 - 0.22
0.0 - 0.074
0.0 - 0,13
0.021
0.0 - 0.025
0,0 - 0.038
0.0 - 0.046
0.0 - 0.1
0.0 - 17
0.0 - 1.0
0.0 - 0.13
0.0 - 0.096
0.0 - 0.11
Average
Concentration,.
(gg/1)
0.014
0.01
0.01
0.09
0.012
0.028
0.3
0.2
0.010
0.016
0.022
0.015
0.03
0.03*
0.025
0.021
0.007
0,016
0.024
0.032
2
0.07*
0.02
0.036
0.007
Av*
Load _
[nas/IOOOa3
4.05
8.18
•
9.26
3.49
3,*5
28.4
102
,4S
.48
.60
1 .7
3.53
.16
1 .3
9.86
1.40
5,57
4.89
3.13
558
12.5
4.41
5.01
1.40
-------
Table V-39
METAL HOLDING AND CASTING
ANALYTICAL DATA
Ferrous Duet Collection Scrubber - Haw Vaatewater
K>
O
Ut
Pollutant
070 Dietby1 phthalate
071 Dimethyl phtbalate
072 Benzo(a)anthracene
076 Chrysene
077 Aeenaphthalene
078 Anthracene
080 Fluorene
061 Phenantbrene
084 Pyrene
085 Tetrachloroethylene
087 Tricbloroetnylene
099 Endrin aldehyde
106-108 PGB 1242, 125*, 1221
109-112 PCB 1232, 1248, 1260, 1016
111! Antimony
115 Arsenic
117 BeryIlium
119 Chromium
120 Copper
122 Leal
123 Mercury
124 Nickel
128 Zino
Muniter of
Samples
Analyzed
32
32
32
32
32
32
32
32
32
32
32
16
16
16
37
38
HO
37
45
53
42
45
53
Number of
Times
Detected at
Quantifiable
Levels
20
25
4
14
9
26
12
26
22
3
2
1
1
1
8
19
3
24
42
48
29
33
53
Concentration
Hange (ng/1)
0.0 -
0.0 -
0.0 -
0.0 -
0,0 -
0.0 -
0.0 -
0.0 -
0.0 -
0.0 -
0.0 -
0.0 -
0.0 -
0.0 -
0.0 -
0.0 -
0.0 -
0,0 -
0.0 -
0.0 -
0.0 -
0.0 -
0.007
Q.W2
1.90
0.036
0.026
0.074
0.1375
0,077
0.1375
0.065
0.11
0.066
0.073
0.023
0.022
0.4
0.11
0.01
0.49
1.1
3
0,0031
0.8
- 11
Average
Concentration
(ma/1)
0.020
0.18
0.006
0,010
0.01*
0.030
0.0163
0.030
0.022
0.01
0.020
0.008
0.002
0,002
0.03
0.02
0.0005
0.07
0.3
0.3
0.0005
0.12
1
Average
Load
(ing/1000m3)
2.16
25.8
0.441
1.36
3.21
8.34
5.61
8.38
2.57
5.21
t3.1
8.38
2.57
0.0060
12.4
45.9
35.3
0.0401
17.7
141
-------
Table V-39 (Continued)
METAL HOLDING AND CASTING
ANALYTICAL DATA SUHHARX
Ferrous Dust Collection Scrubber - Raw Wastewater
ho
o
Pollutant
Aluminum
Ammonia (N)
Cobalt
Iron
Manganese
Oil 4 Grease
Phenols (4AAP)
Suspended Solids
Humber of
Samples
Analyzed
50
36
14
5*
50
H6
49
54
Number of
Times
Detected at
Quantifiable
Levels
50
36
2
54
50
46
49
54
Concentration
Range {mg/1}
0.06 - 222
0.1 - 70
0.0 - 0.013
2.8 - 920
0.25 - 42
1.9-55
0.054 - 59.5
16 - 22,700
Average
Concentration.
(rng/1) '
40.8
27
0.002
98
2.9
13.6
4.5
3,412
Average
Load
(flK/IOOQsr1)
8,290
1,350
0.281
1U,600
477
1,130
1,250
651,000
1
Straight average of available analytical data. Concentrations have not been normalized to account
for flow rates and degree of recycle at sampled plants.
Normalized mass of pollutant generated per unit of production.
•Average load is not available.
-------
Table V-40
METAL MOLDING AND CASTING
ASALITICAl. DATA SIWMARI
Ferrous Melting Furnace Scrubber - Raw Wastewater
K>
O
004 Benzene
011 1,1»1-Trichloroetfcane
023 Chloroform
030 1,2-trans-Diehloroethylene
031 2,4-Diohlorophenol
034 2,4-Dlmethylphenol
039 Fluoranthene
044 Methylene chloride
OSS Naphthalene
056 Hitrobeaxeae
059 2,4-Dlnitrophencl
060 4,6-Dinitro-o-cresol
062 n-BItrosodipbenol
065 Phenol
066 Bis(2-ethyl hezyl)phthalate
067 Butyl benzyl phthalate
068 Dl-n-butyl phthalate
072 Beozo(a)anthracene
Of4 3,4-Benzofluoranthene
075 BenzotkJfluoranthene
076 Chrysene
077 Acenaphthalene
078 Anthracene
080 fluorene
081 Phenanthrene
Number of
Samples
Analyzed
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Number of
Times
Detected at
Quantifiable
Levels
2
2
2
1
1
3
2
1
2
1
1
1
2
3
2
1
1
2
1
1
2
2
3
2
3
Cone en t rat ion
Range (mg/1)
0.0 - 0.030
0.0 - 0.041
0.0 - 0.034
0.033
0.0 - 0.012
0,041 - 0.058
0.0 - 0.061
0.0 - 0.019
0.0 - 0.025
0.049
0.019
0.045
0.027 - 0.043
0.580 - 0.880
0.0 - 0.076
0.0 - 0.044
0,0 - 0.032
0.017 - 0.047
0,019
0.018
0.0 - 0.029
0.0 - 0.037
0.015 - 0.144
0.0 - 0.035
0.015 - 0.144
Average
Concentration
(re/1)
0.014
0.023
0.018
0.033
0,006
0.051
0,031
0.006
0.015
0.049
0.019
0.045
0.035
0.683
0.040
0,015
0.011
0.032
0.019
0.018
0.017
0.020
0.075
0.019
0.075
Average
Load
(»K/1000mJr
26.7
61.8
47.7
88.4
15.4
85.6
82.8
4.21
40.7
130
50.5
120
57.5
1,820
71.6
39.3
28*1
85.6
50.5
47.7
46.3
54.7
95.4
50.5
95-4
-------
Table V-40 (Continued)
METAL HOLDING AND CASTING
ANALYTICAL DATA SUHHABY
Ferrous Melting Furnace Scrubber - Raw Wastewater
o
00
Pollutant
084 Pyrene
085 Tetrachloroethylene
086 Toluene
087 Trichloroethylene
114 Antimony
115 Arsenic
117 Beryllium
118 Cadmium
119 Chromium
120 Copper
122 Lead
124 Nickel
125 Selenium
126 Silver
128 Zinc
Aluminum
Ammonia
Fluoride
Iron
Manganese
Oil & Grease
Phenols (4AAP)
Suspended Solids
Number of
Samples
Analyzed
3
3
3
3
11
11
15
12
12
15
15
15
12
12
15
15
6
6
15
15
11
14
Number of
Times
Detected at
Quantifiable
Levels
2
2
1
2
11
8
6
9
12
14
13
10
12
6
15
15
6
6
15
15
10
13
14
Concentration
Range tag/1)
0,0
0.0
0.0
0,0
0.06
0.0
0.0
0.0
0.17
0.0
0.0
0.0
0.01
0.0
o.<
2.3
2.1
4.8
1< -
9.9
0.0
0.0
188
- 0,062
- 0.077
- 0.011
- 0.063
- 1.*
- 0.17
- 0,02
- 1.50
- 0.60
- 2.50
- 160
- 0.15
- 0.55
- 0.06
- 190
- 87.5
- 12
- 242
227
- 85.8
- 36
- 2,67
- 3,500
Average
Concentration
0.031
0.04JJ
0.003
0.03*
0.64
0.065
0.007
0.56
0.31
1.07
35.0
0.05
0.14
0.013
81.*
28.JJ
7.0
9^.6
76
34.8
8
0,88
839 1
Average
Load
1 Cm*/ 1000m3)2
84.2
116
9.82
91,2
1,140
94.0
4.21
807
359
1,720
89,300
64.6
40.7
12.6
136,000
56,000
4,290
193,000
99,900
35,700
11,400
1,360
,120,000
Straight average of available analytical data. Concentrations have not been normalized to account
for flow rates and degree of recycle at sampled plants.
"Normalized mass of pollutant generated per unit of production.
-------
Table V-41
METAL MOLDING AND CASTING
AHALYTICAL DATA SUMMARY
Ferrous Mold Cooling - Raw Waatewater
ro
o
Pollutant
Aluminum
Iron
Manganese
Oil & Grease
Phenols
Suspended Solids
Number of
Samples
Analyzed
2
6
2
2
6
6
Number of
Times
Detected at
Quantifiable
Levels
2
6
2
2
6
6
Concentration
Range (ng/1)
9.3 - 16
6.9 - 8.9
0.11 - 0.31
1.7 - 22.7
O.OH -' 0.026
80 - 56ft
Average
C o noentration
(ag/1)
12.6
7.7
0.26
12
0.020
331
1
Average
Load
9,3*0
7,720
11U
22,300
17.5
169,000
1
Straight average of available analytical data. Concentrations have not been normalized to account
for flow rates and degree of recycle at sampled plants.
'Normalized mass of pollutant generated per unit of production.
-------
Table ¥-42
METAL MOLDING AND CASTING
AMALITICAL DATA SUHHAHT
Ferrous Slag Quench - Haw Waatewater
Pollutant
034 2,4-Dlmetbylphenol
071 Dine thy 1 phthalate
085 Tetrachloroethylene
08? Trlchloroethylene
118 Cadmium
119 Chronluia
120 Copper
122 Lead
121 Nickel
128 Zinc
JLBBonla (N)
fluoride
Iron
Hanganese
Oil & Grease
PheuolB (UAP)
Suspended Solids
lumber of
Samples
Analyzed
3
3
3
3
6
6
10
10
10
10
11
10
8
13
11
11
13
13
Number of
Times
Detected at
Quantifiable
Levels
3
1
1
1
3
6
7
7
6
8
11
9
8
13
11
11
12
13
Concentration
Range (jpg/l)
0.021 - 0.052
0.0 - 0.077
0 - 0.065
0 - 0.072
0,0 - 0.01
0.01 - 0.08
0.0 - 0.09
0.0 - 1.1
0.0 - 0.10
0.0 - 4,0
1.2 - 18
0.0 - 11
0.07 - 99
1.3 - 7.7
1.0 - 2.7
1.0-7
0.0 - 0.521
15 - 227
Average Average
Concentration. Load
(m«/kkg)z
0.036
0.038
0.022
0.034
0.005
0,06
0.04
0.4
0.03
0.98
6.4
3.4
32.2
4,2
1.6
3,7
0.097
94
72.8
94.0
78.9
88.0
»
191
33.4
491
97.1
667
14,700
1,660
63,800
8,580
3,030
ip25Q
27.3
148,000
Straight average of available analytical data. Concentratlone have not been normalized to account
for flow rates and degree of recycle at sampled plants.
2
Mo realized mm* of pollutant generated per unit of production.
•Average load la not available.
-------
Table V-43
METAL HOLDING AW) CASTIHG
ANALYTICAL DATA SOHHART
Ferrous Vet Sand Reclamation - Raw Wastewater
Pollutant
001 Acenaphthene
034 2,4-Dinethylphenol
035 2,4-Dinitrotoluene
036 2,6-Dinitrotoluene
039 Fluorenthene
044 Hethylene chloride
055 Naphthalene
065 Phenol
066 Bis(2-ethylhexyl)phthalate
066 Di-n-butyl phtbalate
070 Dlethyl phthalate
071 Dimethyl phthalate
072 Benzota)anthracene
077 Aoenaphthylene
084 Pyrene
114 Antimony
115 Arsenic
119 Chromium
120 Copper
122 Lead
124 Nickel
128 Zinc
Number of
Samples
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
9
11
9
13
15
13
15
Number of
Times
Detected at
Quantifiable
Levels
2
4
1
1
2
n
4
6
6
2
1
4
2
1
2
2
9
5
13
14
10
15
Concentration
Range (usE/l)
0.0 - 0.11
0.0 - 0.116
0.0 - 0.065
0.0 - 0.065
0.0 - 0.019
0.0 - 0.023
0.0 - 0.017
0.0 - 1.160
0.0 - 0.019
0.0 - 0.028
0.0 - 0.023
0.011 - 0.055
0.012 - 0.014
0.0 - 0.028
0.0 - 0.027
0.0 - 0.4
0.0 - 0.04
0.0 - 0.32
0.03 - 2.1
0.0 - 2.2
0.0 - 0.95
0.23 - 14
Average
Concentration
(UK/I)
0.049
0.038
0.032
0.032
0.008
0.007
0.009
0.253
0.013
0.006
0.006
0.029
0.013
0.009
0.008
0.089
0.018
0.111
0.584
0.728
0.241
3.18
Average
Load
182
1.12
166
166
31.4
22.8
81.4
1,310
9.34
22.1
23.9
61,2
57.1
61.6
32.8
29.5
102
848
1,160
1,560
540
5,220
-------
Table V-43 (Continued)
HETAL MOLDING AMD CASTING
AHALXTICAL DATA SBHHART
Ferrous Vet Sand Reclamation - Raw Hastevater
Pollutant
Aluminum
Anaemia (V)
Cobalt
Iron
Manganese
Oil A Grease
Phenols (4AAF)
Suspended Solids
Nunber of
Samples
Analyzed
15
15
3
21
15
11
18
21
Niuaber of
TlBBS
Detected at
Quantifiable
15
15
3
21
15
11
18
21
Concentration
Range (TV^/I)
9.4 - 250
0.1575 - 11
0.006 - 0,022
7.2 - 750
O.M5 - 10
1 - 27.7
0.0075 - 9.62
210 - 28,010
Average
Cone entratIon
ClMZ/l} '
Average
Load .
5*
4.27
0.013
139
1.82
7.66
0.99
5,089
258,000
24,000
208
586,000
7,790
58,400
5,860
34,300,000
1
Straight average of available analytical data. Concentrations have not been normalized to account
for flow rates and degree of recycle at sampled plants.
Normalized mass of pollutant generated per unit of production.
-------
Table
METAL MOLDIKG AH> CASTING
ANALYTICAL DATA SlMtABX
Magnesium Grinding Scrubber - Raw Yaatevater
Pollutant
0*4 Metbylane chloride
066 Bls(2~ethylhexyl)phthalate
128 Zinc
Manganese
Oil A Qreaae
Phenol (UAP)
Suspended Solids
Number of
Samples
Analyzed
3
3
3
3
3
3
3
Amber of
Tims
Detected at
Quantifiable
Levels
2
2
3
3
3
3
3
Concentre tion
Range (ae/l)
0.012 - 0.150
0.0 - 0.195
0.38 - 1.TO
0.08 - 0.42
1-11
0.010 - 0.029
10 - 63
Average
Conoentratijon
(•g/1)
*
T
0.081
O.OTO
.16
.28
4.3
0.017
36
1
0,
Average
Load
2.98
2.58
*2.T
10.3
158
0.626
1,320
1
Straight average of available analytical data. Concentrations nave not been norvaliced to account
for flow rates and degree of recycle at sampled plants.
"Normalized masa of pollutant generated per unit of production.
-------
METAL MOLDISG AND CASTMG
ANALYTICAL DATA SUHMAHT
Zinc Casting Quench - Raw Wastewater
Pollutant
001 Acenaphtheoe
021 2,4,6-Trlehlorophenol
022 Parachlorometacresol
024 2-Cbloropheaol
031 2,4-Diehlorophenol
034 2,4-Dimethylphenol
039 Fluoranthene
044 Metbylene chloride
056 4-Nitrophenol
059 2,Jt-Dinltrophenol
065 Phenol
066 Bis(2-ethyl hexyl)phthalate
067 Butyl benzyl phthalate
066 Dl-D-butyl phthalate
070 Dietby1 phthalate
085 Tetrachloroethylene
120 Copper
124 Nickel
126 Zinc
Humber of
Samples
Analyzed
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
3
3
4
Number of
Times
Detected at
Quantifiable
Levels
1
3
1
1
4
3
3
1
1
1
4
4
1
1
2
1
3
3
4
Concentration
Range (mg/1)
0.0 - 0.01
0.051 - 0.13
0.051
0.019
0.01 - 0.03
0.016 - 0.12
0.02 - 0.026
0.0 - 0.021
1.6
0.0 - 0.9
0.011 - 0.051
0.018 - 0.081
0.0 - 0.012
0.0 - 0.05
0.01 - 0.02
0.0 - 0.02
0.06 - 0.16
0.02 - 0.04
3-1 - 350
Average
Concentration
-------
Table V-*5 (Continued)
METAL HOLDING AND CASTING
ANALYTICAL DATA SUMMARY
Zinc Casting Quench - flaw Hastevater
Pollutant
Aluminum
Iron
Manganese
Oil & Grease
Phenols (4AAP)
Suspended Solids
Number of
Times
Number of
Samples
Analyzed
It
it
U
4
U
4
Detected at
Quantifiable
Levels
I
U
U
u
u
u
Concentration
Range Cms/I)
0.1 - 3-5
0.07 - 6.6
0.06 - 0.29
19 - 81
o.oa - o.m
8-94
Average Average
Concentration Load
(mg/1) Cmji/kkg}'
0.98 103
1.8 193
0.12 8.90
38 2,530
0.073 3.67
56 3, OHO
Straight average of available analytical data. Concentrations have not been normalized to account
for flow rates and degree of recycle at sampled plants.
Normalized mass of pollutant generated per unit of production.
-------
Table V-46
METAL MOLDING AND CASTING
ANALYTICAL DATA SUMMARI
Zinc Die Casting - Raw Waatewater
Pollutant
001 Acenaphthene
004 Benzene
006 Carbon tetraohloride
Oil 1t1t1-Trloblorcwthane
021 2,4,6-Trlobloropheno1
022 Paracblortnnetacresol
023 Chloroform
024 2-Chlorophenol
030 1,2-trans-Diohloroethylene
034 2,4-Dinetnylphenol
038 EtJay 1 benzene
044 Methylene chloride
055 Naphthalene
065 Phenol
066 Bl3(2-ethyl hexyDphthalate
068 Di-n-butyl phtbalate
069 Di-n-oetyl phthalate
070 Dietfayl phtbalate
072 Benzo(a)anthracene
076 Chrysene
078 Anthracene
081 Phenanthrene
084 Pyrene
085 Tetracbloroethylan*
086 Toluene
Number of
Samples
Analyzed
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
4
21
21
4
4
4
4
4
Number of
Tines
Detected at
Quantifiable
Levels
1
1
1
1
1
3
1
1
1
1
1
2
2
1
4
4
1
2
1
1
1
1
1
4
2
Concentration
Range (aat/1)
2.5
0,0 - 0.015
0.0 - 0.029
0,0 - 0.044
0.092
0.0 - 0.4
0.0 - 0.067
0.0 - 0.21
0.043
o.o - 0.032
0.018
0.0 - 0.3
0.014 - 0.06
0.0 - 0.46
0.21 - 4.3
0.2 - 0.3
2.8
0.078 - 13
0.075
0.055
0.5
0.5
0.016
0,021 - 0,142
0.012 - 0.027
Average
Concentration.
(UK/I) 1
2.5
0.05
0.01
0.015
0.092
0.13
0.017
0.105
0.043
0.008
0.018
0.08
0.037
0.15
1.5
0.25
2.8
6.5
0.075
0.055
0.5
0.5
0.016
0.083
0.020
Average
Load 2
22,400
24
4.66
7.08
825
1,120
7.95
§0.3
20.6
3.80
161
58.4
77.2
73.4
4,050
1,790
1,340
58,700
672
493
4,490
4,490
143
443
60.3
-------
Table V-46 (Continued)
METAL MOLDING AMD CASTIHG
ANALYTICAL DATA SUMMARY
Zinc Die Casting - law Wasteuater
Pollutant
08? Triohloroethylene
106-108 PCS 12*2, 1254, 1221
109-112 PCB 1232, 1248, 1260, 1016
120 Copper
122 Lead
128 Zinc
Aluminum
Iron
Manganese
Oil & Grease
Pnenols (4AAP)
Suspended Solids
Number of
Samples
Analyzed^
4
2
2
3
4
4
4
4
4
4
4
4
Number of
Times
Detected at
Quantifiable
Levels
2
1
1
3
4
4
4
4
k
4
4
4
Concentration
Ran«e (BK/I)
0.0 - 0.23
0,0 - 0.050
0.0 - 0.056
0.1 - 0.2
0.09 - 0.42
2.3 - 62
2.8 - 5.1
0.93 - 6.9
0.1 - 0.25
759 - 17,100
0.035 - 1.42
604 - 3,800
Average
Concentration,
(UK/l) '
0.063
0,025
0.028
0.13
0.28
18
3.7
2.6
0.16
5,240 10
0.441
1,460 5
Average
Load £
74.6
*
*
1,200
2,370
27,200
22,600
9,100
1,030
,700,000
941
,060,000
Straight average of available analytical data. Concentrations have not been normalized to account
for flow rates and degree of recycle at sampled plants.
2
Normalized mass of pollutant generated per unit of production.
•Average load is not available.
-------
Table V-47
LIST OF 129 PRIORITY POLLUTANTS
Compound Mame Type of C
1 . acenaphthene Base/Neutral
2. acrolein Volatile
3. aerylonitrile Volatile
4. benzene Volatile
5. benzidene Base/Neutral
6, carbon tetrachlorlde Volatile
Chlorinated benzenes (other than dichlorobenzenes)
7. chlorobenzene ' Volatile
8. 1 ,2,4-trichlorobenzene Base/Neutral
9. hexachlorobenzene Base/Neutral
Chlorinated.. ethanes (including 1 ,2-dichloroethane,
1 ,1 ,1-trichloroethane, and hexachloroethane)
10. 1 2-dichloroethane Volatile
11. 1 1',1-trichloroethane Volatile
12. hexachloroethane Base/Neytral
13. 1
11. 1
15. 1
16. chloroethane , Volatile
Chloroalkyl etfaerg (chloroinethyl, chloroethylf and
mixed ethers)
17. bis(chloromethyl) ether (deleted) Volatile
18. bis(2-chloroethyl) ether Base/Neutral
19. 2-chloroethyl vinyl ether Volatile
d, nahthalene
1-dichloroethane Volatile
1,2-trichloroethane Volatile
1,2,2-tetrachloroethane Volatile
20. 2-chloronaphthalene Base/Neutral
Qhlpr4|iated phen.Qlp (other than those listed elsewhere;
includes trichlorophenols and chlorinated cresols)
21. 2,1,6-trichlorophenol Acid
22. para-chloro-meta-cresol Acid
23. chloroform Volatile
24. 2-chlorophenol Acid
218
-------
Table V-4? (Continued)
LIST OF 129 PRIORITY POLLUTANTS
Compound Name
Ulciilo robe nzenes
25. 1 ,2-diehlorobeniene
26, 1 ,3-dichlorobenzciic
27, 1, 4-diehlorobenzene
Dichloroben2idine
28. 3»3f-dichlorobenzidine
Dichloroethyleriep ( 1 , 1-dichloroethylene and
1 ,2-dichloroethylene)
29. 1 , 1-dichloroethylene
30. 1 1 2»tjra,r)s-diohloroethylene
31. 2,4-dichlorophenol
and dichlororoejie
Tvt>e of Compound
Base/Neytrtl
Base/Neutral
Base/Neytral
Base/Neutral
Volatile
Volatile
Acid
32
33
1,2-dichloropropane
1 ,2-dichloropropylene
2,4-dimethylphenol
Q?- 1 o In € n e
35. 2,4-dinitrotoluene
36. 2,6-dinitrotoluene
37. 1 i 2-diphenylhydrazine
38. ethylbenzene
39. fluoranthene
Haloetherp (other than those listed elsewhere)
40. 4-chlorophenyl phenyl ether
41 . 4-brotnophenyl phenyl ether
42. bis(2-chloroisopropyl) ether
43. bis(2-chloroethoxy) methane
es (other than those listed elsewhere)
44. methylene chloride
^5. methyl chloride
46. nethyl bromide
Volatile
Volatile
Acid
Base/Neutral
Base/Neutral
Base/Neutral
Volatile
Base/Neutral
Base/Keutral
Base/Neutral
Base/Neutral
Base/Neutral
Volatile
Volatile
Volatile
219
-------
Table V-47 (Continued)
LIST OF 129 PRIORITY POLLUTANTS
Compound Name
Tvoe of Compound
Halomethanes (other than those listed elsewhere) (Cont.)
47. bromoform
48, dichlorobromomethane
49. trichlorofluoromethane (deleted)
50, dlchlorodifluoromethane (deleted)
51. chlorodibromomethane
52. hexachlorobutadiene
53. hexachlorocyclopentadiene
54, isophorone
55. naphthalene
56. nitrobenzene
Volatile
Volatile
Volatile
Volatile
Volatile
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Nitrophenols (including 2,4-dinitrophenol and dinitrocresol)
57. 2-nitrophenol
58. 4-nitrophenol
59. 2,4-dinitrophenol
60. 4,6-dinitro-o-cresol
Nitrosamines
61. N-nitrosodimethylamine
62. N-nitrosodiphenylamine
63. N-nitroaodi-n-propylamine
64, pentachlorophenol
65, phenol
Phthalat^L esters
66. bis(2-ethylhexyl) phthalate
67. butyl benzyl phthalate
68. dl-n-butyl phthalate
69. di-n-octyl phthalate
70, diethyl phthalate
71. dimethyl phthalate
Polynuc.lea_r_ aroma-tic hydrocarbons
72. benzo(a)anthracene
73. benzo(a)pyrene
74, 3,4-benzofluoranthene
75. benzo(k)fluoranthene
Acid
Acid
Acid
Acid
Base/Neutral
Base/Neutral
Base/Neutral
Acid
Acid
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
220
-------
Table V-47 (Continued)
LIST OF 129 PRIORITY POLLUTANTS
C i n
Polvnu.ear
hydrocarbons (Cont.J
76, chrysene
77. acenaphthylene
78. anthracene
79. benzo(ghi)perylene
80. fluorene
81, phenanthrene
82. dibenzo(a,h)anthracene
83. indeno<1,2,3-c,d)pyrene
84. pyrene
85. tetrachloroethylene
86. toluene
87. trichloroethylene
88. vinyl chloride
Pesticides and metabolites
89. aldrin
90. dieldrin
91. chlordane
and aetabolltes
92.
93.
94.
End°$
4, 4 '-DDT
4,4'-DDE
4,4'-DDD
petabolites
95. Alpha-endosulfan
96. Beta-endosulfan
97. endosulfan sulfate
ndrln and
98. endrin
99. endrin aldehyde
Ejeptaohlojr ,and metabolites
100. heptachlor
101. heptachlor epoxlde
Tvne of Compound
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Base/Neutral
Volatile
Volatile
Volatile
Volatile
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
221
-------
Table V-*»7 (Continued)
LIST OF 129 PRIORITY POLLUTANTS
Compound Name
He ^ac hio r QC y c l_pfoejc an e (al 1 is ome rs)
102. Alpha-BHC
103. Beta-BHC
104. Gamma-BHC
105. Delta-BHC
Polvchlorlnated biohenvls (PCB's)
106,
107,
108,
109.
110,
111,
112,
PCB-1242
PCB-1254
PCB-1221
PCB-1232
PCB-1248
PCB-1260
PCB-1016
Metals. Cvanide and Asbestos
114.
115.
116.
117.
118.
119.
120.
121.
122.
123.
124.
125.
126,
127.
128.
antimony
arsenic
asbestos
beryllium
cadmium
chromium
copper
cyanide
lead
mercury
nickel
selenium
silver
thallium
zinc
Other
113.
129.
toxaphene
2,3,7,8-tetra
CTCDD)
chlorodibenzo-p-dioxj »-
Type of Compound
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Inorganic
Inorganic
Inorganic
Inorganic
Inorganic
Inorganic
Inorganic
Inorganic
Inorganic
Inorganic
Inorganic
Inorganic
Inorganic
Inorganic
Inorganic
Pesticide
Base/Neutral
222
-------
Table V-^8
NON-PRIORITY POLLUTANTS ANALYZED FOR
DURING MM&C SAMPLING EFFORTS
Acidity, free
Acidity, total
Alkalinity (Methyl Orange)
Alkalinity (Phenolphthalein)
Aluminum
Ammonia-N
Calcium
Carbon, Organic
Chloride
Cyanate
Fluoride
Hardness
Iron
Magnesium
Manganese
Nitrogen
Total Phenols («-AAP)
Potassium
Silica, Soluble
Sodium
Sulfate
Sulfide
Temperature
Thiocyanate
Tin
Oil and Grease
Solids, Dissolved
Solids, Suspended
Solids, Volatile
PK
223
-------
Table V-49
SUMMARY OF SAMPLING ACTIVITIES
Pollutants for Hhioh toalyaaa were Parforaed
Plant
00001
00002
04622
04704
04736
06809
06956
07170
07929
ro 08146
to 09094
•^
09*41
10308
10837
12040
15265
15520
15654
17089
17230
18139
19872
20007
20009
20017
20147
50000
50315
51026
51115
51473
52491
52881
53219
Tear
Saapled
1978
1978
1978
19T8
1978
1978
1978
19T8
19T8
1978
1978
1983
1978
1983
19T8
1983
19TB
1978
1978
1983
J9T8
1978
1983
19T6
1983
1978
1983
19T4
1971
1974
1974
19T4
19T4
197*
Priority Orsanios
Ettractablea ' Tomiles
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
I
X
X
X
X
I
X
X
X
X
Pea tio idea
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
ConveotionalB and BoDconventionala
Oil 4 Totel Suspended
Priority Inorganics Grewe Phenol B Sol Ida 41 r«
ill
All
Ci~, Pb
Cr, Cu,
•i, Se,
ill
ia, CtT
Tl, Zn
All
en", Pb
Clf , Pb
Cu, CH~
ia, ClT
Zn
ill
Cr, Cu,
Se, Zn
ill
Cr, Cu,
Sa, Zn
ill
ill
ill
ia, CH~
In
ill
ia, C»-
Zn
Cd, Cr,
•i, 3*,
ill
ill
ill
Cr, Cu,
Se, Zn
ill
Be, Cu,
Zn
Be, C»-
Cu, Pb,
Be, Cu,
Zn
Be, CB~
Be, CH~
Be, Cu,
Zn
X X
, Zn
CH~, Pb, flg,
Zn
, Pb, Se, is,
, Zn
, Zn
, Pb, Hg, 3e, Zn
, Pb, S«, is, Tl,
CK~, Pb, Eg, Hi,
ClT, Pb, Bg, 11,
, Pb, 3*, Ag, Tl,
, Pb, S», is, Tl,
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Cu, CM", Pb, Rs, X X
Zn
X
X
X
CH~, Pb, as, it, x
X
Ci~, Pb, Bg, fi, X
, Hg X
8s, Hi, Zn
CU , Pb, Bg, U, X X
, Hg XX
9 M£ ^
CN , Pb, 1%, Hi, X X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
m.
X
X
X
X
X
X
I
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
Table V-49 (Continued)
OF SAMPLING ACTIVITIES
PoUutMta for ftlch
verc ferforaad
Conventional* and Ho no on vent Ion a la
flint Tear Priority Organies _ Oil i
Munbftr Sampled Entraotmblee foiatileB Pestloidas Priority Inoixanioa Oreaoe
536*2 197*
5*321 197*
55122 197*
5521? 19T«
56123 19?*
56TTt 19T*
56T89 197*
57100 19T*
5T7T5 197*
58589 197*
51101 197*
59212 197*
Cu, Pbj Hs» 11, Zn
Be, CB , %
Cu, Pb, HBji "1, Zn
Be, Cu, CB , Ffc» %, Hi,
Zn
Be, CM, C«", Pb, %, M,
Zn
Be, Ci-, t^
fie, Cu, CB , Pb, RB, m(
Zn
Be, CM"
fie, Cu* cx~, Pb, %, Vlt
Zn
fie, Cu, CI~, 1%, %, HI,
Zn
Be, CI", Hg
Be, CI", Hg
X
Z
z
z
z
X
X
z
Total
Phenols
Z
Z
X
X
X
z
z
z
z
X
X
z
Suspended
aollda
Z
z
X
X
z
z
z
z
z
z
X
z
41
X
X
z
z
z
z
X
z
X
z
z
X
Fe )fe
Z
X
X
X
z
X
X
X Z
z
z
z
z
Ertractsbles o cap rise *aU ao*p
-------
CMMttC
K>
cn
;UPOL*
EVAPORATION
10- IS «PM
STACK
PROCESS; FERROUS FOUNDRY
PLANT: OOOOI
fHOOUCTKMC IO TOWS/PAY
)• METRIC TONS/DAY
CAUSTIC
ADDITION
TOTE IUCKCT
160
1 I" '»LAMPFI
EttVIRONMCKTAL PROTECTION ASENCV
POUNDMY 1MDUSTHY STUDY
WASTEWATER TREATMEWT SYSTEM
WATER FlOW DIAGRAM
ig/ja
FIGURE H-l
-------
PROCESS: FERROUS FOUNDRY
PLANT: 00001
PRODUCTION; ?o TON/DAT
•1 HCTfllC TOW/DAY
K)
PO
CHARGE
VAPORAT ION
74 8PH
STACK
OEH1STER
TO LANDFILL
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTE WATER TREATMENT SrSTEM
WATEA FLOW DIAGRAM
FIGURES:-2
-------
PROCESS:
PLANT:
ZINC DIE CASTING
CM6ZZ
PflOOUCTIO* METAL USED K-8 TONS/DAY
I&2 HETMC TON&QAY]
WATER
DIE CAST me
QUENCHING OPERATIONS
1 ,
1 *
WAS!
EWTER STO
TANKS
iAGE
TO COMTfiACT
HAULER
525 GAL/SHIFT
1.09 8PW
{0.07 I/SCC1
ENvmONHENTAL PROTECTION AOCHCV
FOUMMY INDUS TRY STUOT
•ASTEVATCfl TNCATHCNT SYSTEM
WATER f t-OW DIAGRAM
FIGURE!-3
-------
CITY WATER
RIVER. WATER
PROCESS!
PLANT!
2OOO GAL.
SURGE TANK
015 GPU (O.OO95 t/i«c)
INVESTMENT FOUNDRY
(ALUMINUM)
0*704
PRODUCTION; (5,0 TONS/DAY")
4,54 METRIC TONS/DAY
TO SiVER
5O GPM
(3.2 l/uc)
SOLIDS TO
LAN DF ILL
SAMPLE POINTS
ENVIRONMENTAL PROTECTION ACtNCV
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
Own.
FIGURE 1-4
-------
ro
U)
WELL
WATER
I
PROCESS'. BRASS ft COPPER FOUNDRY
PLANT*. 04736
PRODUCTION; 102 METRIC TONS/DAY
(112 TONS/DAYl
MAKE-UP
J
SAMPLING POINT
RECYCLE
SUMP
ENVIRONMENTAL PROTECTION AOEHCV
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
DWM6-2O-71
X-5
-------
MOLTEN
METAL
MOLTEN
METAL
DIRECT
CWLL
MOLDS
1
H.Z I/MC 1225 GPM)
MAKE-UP FROM TREATED
WELL WATER SYSTEM -
OTNtH
uses
PROCESS:BRASS 9 COPPER FOUNDRY
PLANT: O68O9
PROOUCTIOM: =»550 Tflm/Oay
Mtlric
MAKE-UP
WELL VAT EN
ST3TCM
TO
LANDFILL
SETTING AND
DRAG TANK
TO
DRV WELL
CLEAN-UP ONLY
ENVIRONMENTAL PftOIECTtON AGENCY
FOUNDRY INDUSTRY SIXIOT
WASTE WATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
{FIGURE Z-6
-------
UJ
to
ZQ5 GPM
112.9 I/SEC)
111 GPM
16A (/SEC
L VAPOftATION
4 31.3 GPM
JJ2.2 L/SECi
9O£ GPM (97 2 I/SEC I
EVAPORATION
PROCESS:
PLANT*.
FERROUS FOUNDRY
06SS6
PRODUCT UN; SftO HCTfilC TONS Of IRON/MY
(«00 TONS OF IRON /0*t)
208 METRIC TOMS Of SAND/DAY
(230 TONS OF SANQ/OAY)
27) GPM
117,2 I/SEC)
O GPU
l/SECii
I
DOMESTIC
USES
t
SEP1
SYS1
1C
Eli
PLASTIC
OEPT
N, C.C,
RUNOFF
42 0PM
UNDERGROUND
SPRINGS
1398
BOOJ
l_-
tl GPU
(0.69 I/SEE]
GPM
M/SECJV
!
WATER
j y^
POND
k
C
*
(2.6 MSECt
J
1673 0PM
(99.2 MSEC I
X
I 78 GPM
ft 4,9 l/SCC)
OUTFALL
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
OWN.I/IO/7S
FIGURE V-7
-------
3 GPU (0.32 MM) LOSSES
PLANT:
PRODUCTION:
FAN*
CITY WATER
CRAY IRON FOUNDRY
MELTING SCRUBBED
O7ITO
4 TONS/MY
(3.6 MET NIC TONS/DA V)
SCREEN
OVER
'INTAKE
BOX
Ml -POLYMER
(21 -FLOCCULANT
(3>-NoOH
SLUDGE
TO
LAHOFtLL
210 GAL/DAY
(795 I/DAY)
CNVMtONHCNTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTE WATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
FIGURE U-8
-------
PROCESS: GRAY BOH FOUNDRY
PLANT! 079Z9
PRODUCTION: l« METRIC TOW OF IRON/MY
(129 TONS OF JROH/OAY)
659 METRIC TONS OF MWVDAT
(616 TONS SAKO/OAY)
I*AKE UP
WATCN
DU3T SCftUeaERS
A
SWUNG POMT
ENVWONMENTAL PROTECTION AGENCT
FOUNDRY INDUSTRY STUCK
WSTEWATER TREATMENT S VST EM
WATER FLOW DIAGRAM
FIGURE 1C-9
-------
CITY
WATER
raocc**
PLANT:
romuwv
o«4«
raooucTioic a74a yerwc TONS of METAL/DAY
|0.tl TONS Of VITAL/BAY!
ti ycmic TCMS SANWOAV
(100 TOWS UND HAKOLltVDAt)
fO
Ul
TO
LANOF.LL
TO
OUTFALL
^SAMP
S*MfH-l»6 POINT
CNVIRilNUCNTAL P«(:T( CTION AGENCY
FOONWW MUSTRY STUGV
VASTfiHVCfl TKATUENT SYSTEM
MUCH H.OH DIACRAM
I-10
-------
37 6PM
2.3 I/SEC
43 CIHIx-^A
8.7 i/SEC ^r*
24 6f>M
t.S J/SEC
USED*
3AHP
> 37 CPU
2.3 I/SEC
*-WATCR & SAND
t RECLAIMED
METAL
13 «PM
ae i/scc
72 GPU
4.S t/SEC
LAGOON N*
LAGOON N*
»2 GPU
33 t/SEC
PROCESS: COPPER ALLOY FOUNDRY
PRODUCTION: =»GQMCTRIC TONS/DAY
l=*70 TOWS/OATTI
2.2 I/SEC
O CPU
O I/SEC
? CPU
0.4 MSEC)
f
LA600M Nt t
A
SAiVLlNG KMNT
CNVUtOftllENTAL PNOTtCTION A6CNCV
IHOUSTHY STUDY
WASTIWATER TREATMENT SYSTEM
tiATER fLOW DIAGRAM
FIGURE 2-11
-------
WELTING
FURNACE
SCRUBBER
1
- 2* L/S€C
11 t/SfC—'
CAUSTJC
SLUDGE TO
LANDFILL •*-
SETTLING
TANK
DUST COLLECTION
SCRUBBER
- I 9 L/StC
(21 GPM)
PRQCESS« FERROUS FOUNDRY (GRAY IRON I
PLANT: QS44I
PRODUCTION: 194 METRIC TONS/OAY
{213 TONS/DAY)
SLAG QUENCH
i-/SEC
CFH)
5.0OQ OJtt. /BJ.ICM tMIMI>-
ntncc
-»1 L/3tr,
-IS L/SCG
I2OS OP U)
POND
5-20 ACRES
- S 6 L/9CC
1ST CPU)
(6 t/SEC-
(Z60 SPM1
NOH-CONTACT
COOLING WATERS
(OiL COOLER)
- S.O L/StC
(*7 SPH)
FURNACE COOLING
CNON-CONTACT JWATER
A
SAMPLING POINTS
ENVIRONMENTAL WJOTECTJON AGENCY
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
bwn. 2/24/B4
FIGURE V-12
-------
Uf
CD
PROCESS: ALUMMUH AMD ZNC DIE CASTING
IOSO8
PLANT:
PRODUCTION:
Tw»/0gy
(3-18 Metric ToM/Doyl
Tom/Day
SKIM
OIL
TANK
TO CONTRACT
HAULER
SULFUR 1C ACID
OIL SOLD TO
CONTRACT HAULER {EXISTING)
RECOVERED
ALUM
RECOVERED
ALUM
PROPRIETARY
COMPOUNDS
RECOVERED
ALUM
TANK
GLYCOL. ETC,
REUSE
IN PLACE FOR FUTURE USE
PROPRIETARY
IODINE
COMPOUND
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTE VATER TREATMENT SYSTEM
HATER FLOW DIAGRAM
TO
LOCKIO
SWAMP
INSPECTION TANK
FIGURE 1-13
-------
CASTING WSHWTER,
FLOOR [MAIMS.
SCRAP UACMC WMTCfl
RESW
CLEANING
WASTES
OUST COLLECTOR
WASTEWATER
HOLD MAKING
SHAKEOUT
PROCESS: FERROUS FOUNDRY (GRAY IRON)
PLANT; IOB37
PRODUCTION: so METRIC TOMS/DAY
MOO TONS/DAY)
TO
LjJ
EMULSION
BREAKER
EQUALIZATION
SETTLING TANKS
(2)
OCWW CLARIFIERS
WASTE
SLUDGE
PIT
EQUALIZATION
[EFFLUENT
LIFT
SAMPLING POINTS
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
FIGURE V-14
ILLINOIS RIVER
-------
A—|
ALUMINUM
DIE CASTING
PLANT
ZINC
DIE CASTING
PLANT
PROCESS- ALUMINUM 8 I INC DIE CAS HUG
PLANT: it040
PRODUCTION ALUMINUM 50.8 TONS/DAY
H6.1 MtTRIC TONVOAYJ
ZINC 11.45 TONS/DAY
jjQ.39 METRIC TONS/DAY)
FILTRATE |*.» 6PM
PUMP 1(0.37 t/Mc)
^ - **-•
O/F
TO HECEIVIN6
TANK
TO RIVER
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTCWATCR TREATMENT SYSTEM
WATER FLOW DIAGRAM
FIGURE 1-15
-------
-------
NHj
TtON
PROCESS; MAY IRON FOUNDRY
PLANT: 10020
PRODUCTION: ttt METRIC TONS'or IRON
(620 TONS OF JRON/DAY 1
3338 METRIC TONS OF SAND KANOL ED/DAY
(368O TONS OF SAND HANDLED/DAY)
33OI METRIC TONS OF SAND WASHED/DAY
1364Q TONS OF SAND WASHED/DAYi
TO CENTBAt
TREATMBNT
SAND
DRVCR
SANU TO
SYSTEM
FILTER
TABLE
{
SECONDARY
CLASSIFIER
t
f^C tlO 8PM—
13 2 1/StC t
t
A
i
PHI
CLAS!
4 *
TO
SANITARY
SEWER
6SOOPU
V4t I/SEC.
&H
m 6PM"—A i
•A J/SJtT\j^_J
CORE K.O.
SCRUBBER
.t
MOLDING
'SCRUBBER
.t
MILL
SCRUt
.»
3
A
SAMPLING POINTS
Losses
S5GPM
HYDRO
BLAST
LUMP
BREAKER
USED SAND.
j
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
•WATER FLOW DIAGRAM
DWNJH/78
Rn.»/?/78
R0.2/2t/8O
TO 2/22/80
FIGURE I-17
-------
PRODUCT
89 CPU
II.« I/SCO
PRODUCT
EVAPORATION
as CPI* (i.e
I no GPU
A<4i.2 I/SEC}
t .
PROCESS. STEEL FOUNDRY
PLANT: 1MB*
PRODUCTION* 210 TOMS/DAVltM KKG/0AYI
22 6PU
11.4 I/SEC)
21 CPU
11,3 MSEC!
EVAPORATIVE LOSSES I 6PM (O.I 1/3EC)
3AHO DAVER SCRUBBER
CNVIAONIICNTAI. PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
FIGURE I-18
-------
KX0S3 I/SEC
11ft 6PM1
32.244 I/SEC
(911 6PM}
PROCESS: ALUMINUM FOUMORY
PLANT: tioea
PRODUCTION: »ioo TO»I/OO,
<» DO Metric TQM/Doyl
I5.T5* 1/SCC C«78 6PM)
1216 GPM)
(0.330 t/SEC
(167 6PMI
CHLORIME BOOTH,
HEAT EXHANGERS FOB
URA, WAX MELT OUT AREA
\
i
=^-/HJ-*l
\SIUD6E SCTTLIMS POND/ «
NO
FtOW
NORTH SETTLING POHO
POINI
OO2
OOt
ENVmONMENTAL PROTECTIOM AGENCY
FOONO«V INDUSTRY STWDY
WASTEWATEH TREATMENT SYSTEM
WATER FLOW DIAGRAM
FIGURE
-------
DUST COLLEC1IOM SYSTEM
EVACOOMION
DUST
COLLECTORS
-o.a I/sec
(7 9 emt
PROCESS* FERROUS FOUNDRY |GH AY HONI
PLANT; 1T250
PRODUCTtOf* 41.4 METRIC TONS/SHIFT
445.5 TONS/SHirM
- 56 L/«CC
£
q> - ~ B
1
Ml 6PM|
SETTLING AMD
RECIRCULATKM TANKS
- OSl L/SEC
<• SPM
MAKE-MP
CUPOLA EMISSIONS CONTROL
<40«PH|
?*J
t
«,i i/aac
lew CPHI
VENTURI
| ft—MAKE-UP
A ^—«•» i
_T *
__ tiam
SETTLING TANKS
SWHI'LiNG POINTS
SLUDGE
REMOVAL
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
DMt.Z/23'M
FIGURE V-20
-------
ASSEMBLY AREA DRAINS
HONFOUHORY
WASTE TREATMENT AREA
PROCESS: imc a AI.UHINUU FOUNDRY
PLANT: wie
PRODUCTION: AlwftiM*»SO Tain/Day
(»27 Mttric Tb*»/Do»)
»5O TOM/Day
(»4S Metric Ton/Day)
CITY WATER
-152? I/MS
(242
SETTLING BASIN
OIL
SEPARATOR
A ^
i^i
STORAGE
TANKS
•TO OUTFALL
ASAMPLING F
-------
PROCESS: BRONZE FOUNDRY
DUST COLLECTION
PLANT: I8i72
FAQDUCTiON; 48 TONS OF 8AND/DAY
(40.0 METRIC TONS OF SAMVMYl
C4 TONS OF METAL/MY
(21* HETfilC TONS OF METAL/GAY I
CLEAN AW
OUST LADEN
AIR
CITY WATER
LEVEL CONTROL VALVE
WATER
TO LANDFILL
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
MH2/2I/79
FIGURE 3C-22
-------
CITY WATER
.
»« Will
L
NORTH END
DUST COLLECTION
SCRUBBER
L/S€C
SOUTH END
DUST COLLECTION
SCRUBBER No 10
Z-S2 L/MC
(40 QPM)
SOUTH END
COLLECTION
SCRUBBER No. 15
PROCESS; FERROUS FOUNDRY JGRAY IRON)
PLANT. 2000?
PRODUCTION: 85 METRIC TONS OF STEEL/DAY
(94 TONS/DAY)
123 METRIC TONS OF SAND WASHED/DAY
(138 TONS /DAY)
* TO POTW
SLUDGE TO DISPOSAL VIA TANK TRUCK
TO COMPANY-OWNED LANDFILL.
SAMPLING POINTS
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
FIGURE ¥
-------
EVAPORATIVE LOSSES
cjT^ i k 15 lAtc (25 apml '4
10 3 I/MC — ' V V V
"" VACUUM K,LM OUST J K|L(j JJ^ CHROMITE
^ ^~XV SCRUBBER COOLER SCRUBBER
J ^ i
1^ If k! L* W
i ' ± „
' T- A, i 5| j/*>c t^4 gpini -^ t > 4,04 !/!•£.
SAND ^ SAND A 14 3» IAec.1228 tfmt fc ^ ^ ' 4 «Pml
WASHER ^^ ^
i i i ^ ^
PROCESS STEEL FOUNDRY
PLANT- aooos
PRODUCTION 191 METRIC TONS OF STEEL/DAY
*413 TONS OF STEEUOAY)
2O9 METRIC TONS OF SAND/DAY
(210 TONS OF SAND/DAY)
-7, . . /-
\ r\ / '
L i POND «* J
/ f|73 gpnt} \ «T
BECTCLE PUMP STATION POND N« 4
CITY
I i i 1
H«S DUST N* 3 DUST N1 3A DUST N» 2 OUST < •— — fl.77 I/MC.
COLLECTOR COLLECTOR COLLECTOR COLLECTOR " * *
11 06i lrt«c *s OOii t/iat. 1
-------
to
Ln
0
I
WANNEY WELL «-IME PUMP- SEAL
SOFTENED WATER
("NTAKE WATER1 WATER wccw.
i i
HEAT CMCHANGE
COOLIW WATER
PROCESS' BRASS » COPPER FOUNDRY
PLANT? man
PRODUCTION: SIS METRIC TONS/ DAY
(5T9 TONS/DAYJ
tn 0 t/stc A— * T» t/StC «J>— « »» t^tC
lire cm) I era own I Hi em)
121 L/MC — <
lifts epttt
<
/\ SAMPLING POIN1S
EtfAf fVA* „
A ^-'26i/sic A -—i-'»L/sec Jt
Jr^ (ZO«P« *^ IJOCI-III (
DIRECT CHILL DIRECT CHILL
> NalB4 No 2,385
y \. J *~'*7 L/?!5
fv j V ^ V •
\l *
(tSlO OI*t*S lW956P>*t '•• L/SEC— «J
WEST HOT WELL EAST MC
I2O t/IEC — eL 4
mm CPU) f |
IM6M1J "\ I— * 1
EW ^ \ COOLING /
\ TOWER /
I
>— 40<»-/s€C COLD WELL
felSSSPM) 1.UL.W Wtl,«-
' - lm - - . . ._. g
MAKE UP
4C«€C-4> EV#P . ,. , ..„
rroPM) T fx^"? f^
NON-FOUNDRY
OPERATIONS < >—
£— »« *t/irc
>T WELL
19.4 L/SEC
K«4 omi
wise
SOURCES
< > — t.W L/MC
1300PM)
/-liT.TL/SEC | 1 [
/ (1K6PH) jj ' '
\ ^ it /Ir
> tW.T L/lfC
POLfMER
«!•-
9i r
*** ^ij
i
o r~ ^^
~\
<•& *
| neciwiNB ^ — 1_
1 TANK 1 — r1 r *1
b^i ^
I CLARIF1ER i /
* — ^ ^^ *— •«« t/SEc
— -^_^-- (310 0PM 1
U-T""^v_ VACUUM
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
?SJ^???* _ , Flftt IRF V T 1
-------
DIE COOLING
WATCH SYSTEM
A
KS
in
OIL
XKH.JNO WATEA
SYSTEM
A
LEAKAGE
0 0PM(0
DIE CASTING
MACHINES
\__.PAN /
LEAKAGE
0 0PM fO I/SEC)
PROCESS: ALUMINUM FOUNDRY
PL ANT i tOI47
PRODUCTION: * 120 Tout/Day
OtO» Metric Tent/ Day I
DIE LUBE WASTES
COLLECTION
SYSTEM
CYCLONIC
\ / SEPERATOR
1
PORTABLE TANKS TOt
-------
Ul
UMt£ WATiB
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OUST OOLLECrOD
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16& ME1WC 1CMS DAY
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WAII fl f tOW UAGHAM
FiGUBE V-2?
-------
EVAPORATION
tffl
PAOCCSS: FERROUS FOUNDRY (8RAY IRON}
PLANT; sosis
PRODUCTION*
OUST COLLECTION 1098 METRIC TOWS/DAY
-------
OTHER
USES
PLANT WATEfi SUPPLY
2.649.000 I/DAY (700,000 GAL/DAY)
£
BAG HOUSE
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3
0
U
X
tt
UJ
CD
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0
/
PROCESS: FERROUS FOUNDRY (GRAY IflONl
PLANT: sicwe
PRODUCTION;
DUST COLLECTION 24O METRIC TONS/DAY
(Z65 TONS/OAYI
43 METRIC TONS/DAY
(60 TONS/DAY)
408 METRIC TONS/DAV
(450 TONS/DAY*
SANO WASHING
I BLOWER
SOLIDS
PIPE
MACHINE
•13.8 I/SEC
(220 CPU)
392 i/SEC
IC2I GPMt
.6.31 I/SEC
/(tOO 6PM)
SAND WASHING
SYSTEM
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WATEA
19 I/SEC
/~|»OI GPU)
POINTS
79,330 I/OAY
,- ,
/ (3»,5aO GAL /OAY)
12 dfi. LAGOON
TO RiVEH
ENVIRONMENTAL PROTECTION AGENCY
FOUNDHY INDUSTRY STUDY
WASTEMMTER TRCATUENT SYSTEM
WATER FLOW DIAGRAM
Dun, 5/11/79
I I I
FIGURE 5-29
-------
to
Ui
Ul
PROCESS: FERROUS FOUNDRY (STEELI
PLANT- SHIS
PRODUCTION:
DUST COLLECT ION- 6*7 MMric T
-------
NJ
yi
PROCESS: FERROUS FOUNDRY (bitEL 1
PLANT: 5H73
PRODUCTION:
SAND WASH INC 29 METRIC TONS/DAY
5.7 I/S£C
(90 6PM)
li • • •
132 TONS/OAVI
CITY WATER
SUPPLY
EVAPORATIVE LOSS
0.65 t/SEC
(10 GPM1
DE WATERING
TABLE
5 I/SEC
(00 GPMI
3.6 METRIC TONS*»Y
{4 TONS/OAYl
METRIC TONS/DAY
116 TONS/DAt)
SETTLING TANK
DISCHARGE TO
RIVER
5 I/SEC (BO GPMJ
SOLIDS TO
DISPOSAL
SAMPLE POINT
PROTECTION AGfNCY
ENVIRONMENTAL
RETURN TO
SAND SYSTEM
16.1 METRIC TONS/DAY
{20 TONS/DAY)
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT STSTEU
WATER FLOW DIAGRAM
FIGURE yn-3i
-------
PROCESS' FERROUS FOUNDRY(GRAY IRON!
PLANT 52431
PRODUCTION:
MELTING- 8 Uttric Tom/Day
(9 Tw
-------
-Coating Wai*
(Cil/ Water!
PROCESS: FERROUS FOUNDRY{GRAY IRON)
PLANT: 52881
PRODUCTION:
UELT1N& 78 Miinc Tons/Oay
(86 Tons/Day)
Mai*-up Walw
(C*l» Watut
m Hunt .
16T7t 7 ,
>• 147 l/i*c »
/^ (550 flpn)
f
TRAP
TRAP
I hit Ditchoig* has
tw*n
Wwto Sat in Stack
SAUPL1M6 POINT
ENVIRONMENTAL PHOTCCTIOH *GCNC»
FOUNOMV 1NOUSTRV STUDY
WASTE WAT£H THEATUtKT SYSTEM
WATER FLOW DIAGRAM
-[FIGURE g-33
-------
PROCESS* FERROUS FOUNDSY IGHW IRON|
PLANT! 53219
PRODUCTION'
OUST COLLECTION 59 M»lfie Toni/Oajr
(€5 Tom/Day!
MELTING; 12 7 y«t«c
114 Tom/Dayl
VENTUfll
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(150 gpm)
Cilj Walv
Supply
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ENVIRONMENTAL PROTECTION ACENCV
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
Diicharga lo
Sgnilory &*<••)
FIGURE 3T-34
-------
14.3 I/SEC
WET OUST
COLLECTOR
WET OUST
COLLECTOR
II 3.6 t/SEC
laoo GPU)
LIME
(2 SO GPW)
WON -CON TACT
COOLING WATER
-\.
PROCESS: FERROUS FOUNDRY (GRAY 1ROMI
PLANT: 33«42
PRODUCTION:
OUST COLLECTION' tOK METRIC TONS45AY
II20Q TONS/DAY}
-H3.6 l/SEC
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»4.B MSEC
(2451
SETTLING
CHAMBERS
DISPOSAL
1,16 METRIC TONS/HR
(1.9 TOM5/HR)
DISCHARGE TO
SEWEK OR
REUSE
POINT
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY (HOUSTBt STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
hwn 5/18/7'
1 I I
FIGURE 3-35
-------
' ^COOLING WATER
(CITY WATER)
CUPOLA
I
QUfHCHER
Wtl SLAG
QUt NCHIHG
MAKE IP WATER
ICITV WATER)
34.5 t/SEC
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COOLING
WATER DISCHARGE
(CITY WATER!
I
PROCESS: FERROUS FOUNDS Y (GRAY IRON)
PLANT; s«2i
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(IO5 TOWS/DAYl
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I
I5.B i/sec
(250 GPMl
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TANK
SOLIDS TO
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- 75.? I/SEC
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TO DISPOSAL
TIM Dttchwge ft
been Eimnolwi
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
r i \
IGURE 3C-36
-------
PROCESS: FERROUS FOUNDRY «mv IMONI
PL AMI 93122
PRODUCT WHS
DUST COLLECTION' 7732 Mtlfic Tow/Da,
18947
ELECTRIC
FURNACE SHOP
261 t**c
(414 «M>)
MISC DRAINS
COOLING
WATERS
Cooling Wotw)
API
SEPARATOR
KOLENE
UNIT
17,4
lift ffMtl
CASTING. COOUNG
CORE ROOM AREAS
FUGITIVE
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DUST
COLLECTORS
VACUUM
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r to
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A SAMPLING POINT
ENVIRONMENTAL PROTECTION AGENCY
Solids In
Diteoial
1*4,l !/••«
(2600
FOUNDRY INDUSTRY STU0V
WASTEWATER TMCATUCMT SYSTEM
WATER FLOW DIM HAM
RE CIRCULATING VWTEN SUMP
I-3 7
-------
PROCESS- ft*HOUS FOUNDRY ««AY 1NOH1
PLANT' 55217
PRODUCTION:
DUST COLLECTION: 1897 y*uw ToH
I2O9I
MELTING. 197 HUtie too»/CW|
1217
S7
fc»J »J—
^—-F»0i« Mil W*
-UOU-UP mum
MOLD IKS AND
CLEANING
DUST COILECTODS
O O
SLAG CAR
ENVIRONMENTAL PROTECTOH
FOUNDRY INDUSTRY STUDY
WASTE WATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
Item plan) 5O3I5
IGURE IZ-38
-------
FERROUS FOUNDRY {GRAY IRON)
56123
PLANT
WATER —YtaT
SUPPLY "~
178 METRIC TONS/DAY
(196 TONS/DAY!
3.2 I/SEC
JL (5O
0,63
00 CPM)
WATER SEALS
8 MISC. DRAINAGE
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
DISCHARGE
TO SANITARY^
SEWER
FIGURE 3L-39
-------
an
ui
MAKE-UP
WATER
COOLING
TOWER
COOLING WATER
(CtTY WATER)
SLOWDOWN
C U PO L ft
0 UENCHER
WET SLAG
QUE NCHtNG
MAKE - UP WAI EH
(CITY WATER)
SOLIDS TO
UISPOSAL
Vf. NTURI
SECONDARY
CL ARIF IE R
TANK
HYDRA TED
LIME
J_c
SOL IDS ro
DISPOSAL
DRAG
TAMK
15.6 I/SEC
(2 SO GPM)
?5.7 I/SEC
11200 GPM)
DISCHARGE
ELIMINATED AFTER I9T4
PROCESS: FERROUS FOUNDRY WJWt IRON!
PLANT; serri
PRODUCTION:
DUST COLLECTION 2277 METRIC TONS/DAY
12510 TONS/DAY)
MELTING 175 METRIC TONS/DAY
(193 TONS/OAY)
AFTER COOLER
SEPARA TOR
WASTE GAS
TO STACK
DU3T
COLLECTOR
SYSTEM
I
MAKE-UP
WATER
DRAG TANK
SOLIDS TO
OIS POSAL
POINT
DISCHARGE TO
SANITARY SEWER
3.28 I/SEC
(52 CPU)
ENVIRONMENTAL PROTECTION AGENCY
FOUNORV INDUSTRY STUOt
WASfE*ATE» TREATMENT StSTEII
WATER FLOW DIAGHAM
I I
I- 40
-------
PROCESS:
PLANT;
PRODUCTION;
MELT IMG
FERROUS FOUNDRY (GRAY IRON)
S6789
67 METRIC TONS/DAY
<74 TONS/DAYJ
-GAS STREAM
FLOW
EVAPORATIVE LOSS
to
6.31 I/SEC
(100 CPU)
AGENCY
SOLI OS TO
DISPOSAL
COLLECTION
BOX
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
FIGURE
-------
f DSSCHARGE TO SANITARY
I SEWER 2.7 I/SEC (42 GPM)
^ A
2
TO
DISPOSAL
-L
1
•
==-*=--_
i>
—
M 1
•-WELL
SOLIDS TO
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L
SETTLING
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CATCH
BAStN
1.6 t/S£C.
W(25GPMl TO
SANITARY
SEWER
PROCESS: FERROUS FOUNDRY WHAY IRON)
PLANT: STIOO
PSODUCTION:
DUST COLLECTION 1814 METRIC TONS/DSY
(2000 TONS /DAY}
MELTING 319 METRIC TONS/DAY
(352 TONS/OAY)
\ /\ A A A /
OUST
TO
DISPOSAL
SAMPLING POINT
EXHAUST GAS FLOW
ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
Dnm.S/H/7'
(FIGURE IT-42
-------
Evaporoti»t
L0M
Go* StrMvn
Flow
PROCESS- FERROUS FOUNDRY 1GHAY I ROM I
I»LAIIT! 5T?F5
PKOOUCTION:
DUST COLLECTION- 34.9 M*ttic Tom/Day
(383
UtLTlHO- 2) Utttic Ton*/Do,
t2S
Crtv
00
»,4T !/•«-
mo
x:
FWymtf
MIXING
TANK
Polymtr
OfiAG
TANK
/ -i-
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fcsi
^ ... .y
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A
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OO
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FOUNDRY IMOUStm STUDY
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WATER FLOW DIAGRAM
V2UT9
t=±
FIGURE It-43
-------
CITY WATER
SUPPLY
1.2 I/SEC
(SO GPU)
PROCESS; FERROUS FOUNDRY (GRAY IRONI
PLANT: seaas
PRODUCTIONS
ME If! NO 36 METRtC TOMS/DA V
(4O TQNS/DAYl
VEN1URI
GAS STREAM
FLOW
SOLIDS TO DISPOSAL
1,36 METRIC TONS/CAY
II.S
t:
6.31 I/SEC
(IOO 0PM)
ONE DAY RETENTION
EACH SUMP
(109,763 |
29.0OO GAL)
SOLIDS REMOVAL
BI-MOHTHLT
SAMPLE POINT
_€MVIRONMENTAL PROTECTION AGENC»
FOUNDRY INDUSTRY STUOV
WASfEWATER TREATMENT SYSIfM
WATER FLO* DIAGRAM
T I I
FIGURE 1C-44
-------
o
PROCESS:
PLANT;
PRODUCTION!
DUiT COLLECTION -«36T METRIC TONS/DAY
(7O2O TQNS/UAVt
SAND WASHiNO I6O METRIC TONS/DAY
!I76 TONS/DAY I
FERROUS FOUNDSv cuat IRONI
NOW-COMTACT
COOLING WATER
136
12130 QPM)
^—-MAKE-UP FLOW
AS REWIRED
i/SCC
I70O 6PM»
MOLDING A CLEANING
OUST COLLECTORS
U2 INTERNAL RECIRC.
PACKAGE UNITS
SAND
3LU B HY
63
((000 GPM)
55 I/SEC
(390 0PM)
LAOOQH »f
LAOOOM "I
WSCMABBE TO
CREEK
107 »/SEC
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ENVIHOHMENTAL PROTECTION AGENCY
SAND TO REUSE
10 METRIC TONS/MR
III TON3/HR)
INDUSTRY STUDY
WASTEWATER TREATMENT SYSTEM
WATER FLOW DIAGRAM
FIGURE 1C-4 5
-------
;
i
E— -Citj Wilw Supply
\
"j
SOFTENERS D1SPERSAN1
PROCESS FEMHOUS FOUNDRY I STEEL 1
PLANT- 59212
PRODUCT i ON >
OUST COLLECTION- 2612 Uibic ToM/Day
tZeSO ToM/Oarl
MELTING- 168 MttrK -ftmt/Oof
1183 Tnm/C«yl
1 /— Non-eanlMI Cooling Water
BackL* / 65J '*"* 000° *ol/tOBl
^ / 1 1
/ («/*•! lop dull ^ tdvQtftt thru ftctt ^-
i i
• flbt Ai w 2Z-' i^tct3sQ ip*t^ — < '
>-^Mofc«-«p *
1 QUENCHING CYCLONE
« -—. SFP*B*T'W?
OUST
COLLECTOR t O.Ub M*a(<.l gpm)
j 1 r-2aaZ f 1 COAGULANT 1 1 ACIO | « >
I 1 i Cli— f I
IV — f
DRAG TANK ™
^\ J^L ^^^ , .
t~str 1 ft X
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r25 2 r/Me MOO gemi
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f
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ENVIRONMENTAL PROTECTION AGENCY
FOUNDRY INDUSTRY STUDY
WASTE WATER TREATMENT SYSTEM
WATER FLO* MAC* AM
>» VI 7/7 9 I
I
1-46
-------
-------
SECTION VI
SELECTION OF POLLUTANTS TO BE CONSIDERED FOR REGULATION
Section V presented data from metal molding and casting plant
sampling visits and subsequent chemical analyses. This section
examines those data and discusses the selection or exclusion of
pollutants for potential regulation. Table V-47 lists the 129
priority pollutants considered in this analysis. The
conventional pollutants and pollutant parameters considered in
this study are oil and grease, total suspended solids {TSS), and
pH. The nonconventional pollutants considered are total phenols
(4-AAP), aluminum, iron, magnesium, and ammonia.
A brief discussion of each pollutant detected at a quantifiable
concentration in the raw wastewater is available in Section 22,58
of the record for this rulemaking. That discussion provides
information concerning where the pollutant originates (i.e.,
whether it is a naturally occurring substance, processed metal,
or a manufactured compound); general physical properties and the
form of the pollutant; toxic effects of the pollutant in humans
and other animals; and behavior of the pollutant in POTW at the
concentrations expected in industrial discharges.
RATIONALE FOR POLLUTANT SELECTION
The discussion that follows describes the analysis that was
performed to select for or exclude pollutants from further
consideration for limitations guidelines and standards.
Pollutants were considered for regulation if they are present in
the raw wastewater at concentrations treatable by the
technologies considered as model technologies in this rulemaking,
or if they are believed to be present in the wastewater based on
engineering judgement of raw materials and production processes
employed.
Pollutants were excluded from further consideration if they were
not detected in the raw wastewater, if they were only detected
below quantifiable or treatable concentrations, or if they were
detected in only a small number of sources. Paragraph 8{a)(iii)
of the modified Settlement Agreement provides that the Agency may
exclude pollutants from categorical limitations and standards if:
"3, For a specific pollutant, the pollutant is not
detectable (with the use of analytical methods approved
pursuant to 304{h)of the Act, or in instances where
approved methods do not exist, with the use of
analytical methods which represent state-of-the-art
capability) in the direct discharges or in the
effluents which are introduced into publicly-owned
treatment works from sources within the subcategory or
category; or is detectable in the effluent from only a
small number of sources within the subcategory and the
273
-------
pollutant is uniquely related to only those sources; or
the pollutant is present only in trace amounts and is
neither causing nor likely to cause toxic effects; or
is present in amounts too small to be effectively
reduced by technologies known to the Administrator; or
the pollutant will be effectively controlled by the
technologies upon which are based other effluent
limitations and guidelines/ standards of performance,
or pretreatment standards."
The final selection of pollutants considered for regulation is
presented in Sections IX through XIII, based upon a variety of
factors explained there.
The end-of-pipe treatment technologies relied upon to determine
treatable levels in this analysis include lime precipitation,
settling, and filtration for priority metal pollutants, and
include oil skimming, emulsion breaking, settling, and carbon
adsorption for organic priority pollutants. These technologies,
as well as the classes of pollutants which they control, are
discussed in detail in Section VII. The Agency assumed that each
priority organic pollutant found in metal molding and casting
wastewaters can be treated to a concentration of 0.010 mg/1 using
carbon adsorption. The Agency determined that each priority
pollutant metal found in metal molding and casting wastewaters
can be treated to various specific concentrations, all less than
0.3 mg/1, using lime, settle and filter technology. Section VII
presents the actual treatment effectiveness concentrations that
can be expected for each priority pollutant based upon the
various control and treatment technologies considered.
In the analysis of pollutants detected in each subcategory, EPA
has defined "detected in a small number of sources" as detected
in a ratio of one or fewer samples out of every seven samples
analyzed. If less than seven samples were analyzed then it was
judged that not enough data were available to consider excluding
the pollutant for this reason. The ratio of one in seven was
determined to be a small number of sources because it ensures
that pollutants excluded by this criteria were found in at most
one sample, when daily samples were collected over three days in
at least three waste streams.
POLLUTANT SELECTION BY SUBCATEGORY
While the Agency solicited data on the presence and absence of
priority pollutants in the data collection portfolio, the
selection of priority pollutants for regulatory consideration has
not been based on those responses. The Agency found that most of
the responses to that solicitation were not definitive!
pollutants were "believed" to be absent or present. Rather, the
Agency has based the selection of priority pollutants for
regulatory consideration on the extensive raw wastewater sampling
data base developed under its supervision,
274
-------
The pollutant selection analysis is performed on a subcategory-
by-subcategory basis. For each subcategoryr the selection and
exclusion of conventional and nonconventional pollutant
parameters is discussed first. Following that, the selection and
exclusion of priority pollutants is presented. Tables VI-1
through VI-10 present the frequency of occurrence of priority,
conventional and nonconventional pollutants during EPA's sampling
program. Priority pollutants that do not appear on the frequency
of occurrence tables were never detected at quantifiable levels
in any of the samples collected at plants within the respective
subcategory.
Organic Priority Pollutant Selection by_ Process Segment
Tables VI-11 through VI-15 present the organic priority
pollutants considered for regulation in each process segment of
each subcategory. Organic priority pollutants not listed on
these tables are not considered for regulation. These tables
list all the organic priority pollutants selected for further
consideration for limitations in each subcategory {see discussion
later in this section).
Pollutants were allocated to each process segment within a
subcategory based on their presence in the raw wastewater of that
process segment. Where no organics data were available for a
particular process segment/ but organics were expected to be
present based on engineering judgement of the process involved,
organics data were transferred to that segment from similar
process segments. Details supporting data transfers are
presented in Section V. For those segments where data were
transferred/ pollutants were selected only if they were present
in a treatable concentration in the process segment providing the
data, and also were selected for further consideration in the
subcategory of interest.
These data transfers are listed below:
275
-------
Transfer of Data
To;
Aluminum Subcategory
Dust Collection Scrubber
Mold Cooling
Copper Subcategory
Casting Quench
Investment Casting
Melting Furnace Scrubber
Ferrous Subcategory
Investment Casting
Mold Cooling
Magnesium Subcategory
Casting Quench
Dust Collection Scrubber
Zinc Subcategory
Melting Furnace Scrubber
Mold Cooling
From:
Aluminum Melting Furnace Scrubber
Aluminum Casting Quench
Copper Mold Cooling
Copper Direct Chill Casting, Dust
Collection Scrubber, and Mold
Cooling
Copper Dust Collection Scrubber
Aluminum Investment Casting
Ferrous Casting Quench
Aluminum Casting Quench
Magnesium Grinding Scrubber
Ferrous Melting Furnace Scrubber
Zinc Casting Quench
Pollutant Selection for the Aluminum Subcategory
Conventional and Nonconventional Pollutant Parameters
Four conventional and nonconventional pollutant parameters were
selected for further consideration in this Subcategory, and are
listed below:
oil and grease
total phenols (4-AAP)
total suspended solids (TSS)
pH.
Total phenols were only selected for further consideration in the
die casting, dust collection scrubber, and melting furnace
scrubber process segments, because the average concentration of
total phenol in these process segments is above treatable levels.
Oil and grease, total phenols, and TSS are selected for further
consideration because they were each found in raw wastewater
samples in concentrations exceeding those achievable by
276
-------
identified treatment technologies. Table VI-1 shows the
frequency of occurrence of these three parameters, along with the
range of pH values observed in this study. In addition, these
three pollutant parameters are expected to be present in the raw
wastewater based on their presence in the raw materials and
production processes employed by the plants in this subcategory.
Furthermore, limits on oil and grease, total phenols, and TSS
ensure effective removal of priority organic and precipitated
metal pollutants because these bulk parameters provide a good
indication of overall treatment system performance* Oil and
grease, total phenols, and TSS are commonly regulated in existing
permits.
The 24 pH values measured in aluminum subcategory
ranged from 5.4 to 8.7* Review of pH data can be an
means of determining whether a treatment system is
properly. Effective removal of metal pollutants by
treatment requires careful control of pHj the control
within desirable limits is readily achievable
subcategory* Therefore, pH was selected for
consideration for regulation.
Priority Pollutants
wastewater
effective
operating
chemical
of pH to
in this
further
The frequency of occurrence of the priority pollutants for the
aluminum subcategory is presented in Table VI-2 at the end of
this section. That table is based on data for the raw wastewater
from four process segments - casting quench, investment casting,
melting furnace scrubber, and die casting. The following
discussion is based on information included in Table VI-2.
Priority Pollutants Never Detected or Never Found Above The_ir_
Ana lyticaJT Quant ification ConcentratTon
The priority pollutants listed below were not detected or found
above their analytical quantification concentration in any
wastewater samples from this subcategory, nor is there any reason
to expect them to be present in the wastewater based on the
Agency's review of raw materials and production processes
employed; therefore, they are not considered further for
regulation:
2. acrolein
3. acrylonitrile
8. 1,2,4-trichlorobenzene
9. hexachlorobenzene
12. hexachloroethane
14. 1,1,2-trichloroethane
16. chloroethane
17. bis(chloromethyl)ether
(deleted)
19. 2-chloroethyl vinyl ether
20. 2-chloronaphthalene
25. 1,2-dichlorobenzene
26. 1,3-dichlorobenzene
56. nitrobenzene
61. N-nitrosodimethylamine
69. di-n-octyl phthalate
74. 3f4-benzofluoranthene
75. benzo(k)fluoranthene
79. ben2o(ghi)perylene
82. dibenzo(a,h)anthracene
83. indeno{l,2,3-c,d}pyrene
88, vinyl chloride
89. aldrin
90. dieldrin
91. chlordane
92. 4,4'-DDT
277
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27. 1,4-dichlorobenzene 93.
28. 3f3'-dichlorobenzidine 94.
29. 1,1-dichloroethylene 95.
30. 1,2-trans-dichloroethylene 96.
32. 1,2-dichloropropane 97.
33. 1,3-dichloropropylene 98.
35. 2,4-dinitrotoluene 99.
36. 2,6-dinitrotoluene 100.
37, 1,2-diphenylhydrazine 101.
40. 4-chlorophenyl phenyl ether 102.
41, 4-bromophenyl phenyl ether 103.
42. bis(2-chloroisopropyl) ether 104.
43. bis(2-chloroethoxy) methane 105.
45. methyl chloride 113.
46. methyl bromide 114.
47. bromoform 116.
49. trichlorofluoromethane 117.
(deleted) 118.
50. dichlorodifluoromethane 125.
(deleted) 126.
51. chlorodibromomethane 127.
52. hexachlorobutadiene 129.
53. hexachlorocyclopentadiene
54. isophorone
4,4'-DDE
4,4'-ODD
Alpha-endosulfan
Beta-endosulfan
endosulfan sulfate
endrin
endrin aldehyde
heptachlor
heptachlor epoxide
Alpha-BHC
Beta-BHC
Gamma-BHC
Delta-BHC
toxaphene
antimony
asbestos
beryllium
cadmium
selenium
silver
thallium
2,3,7,8-tetrachlorodi-
benzo-p-dioxin (TCDD)
Pesticides (pollutants 91-93 and 101-105) were reported as
detected in samples of aluminum die casting water. However, EPA
is excluding pesticides from regulation in this subcategory
because EPA believes the pesticide data were incorrectly
interpreted by the analytical laboratory, and, based on our best
judgement, EPA has no reason to believe that pesticides should be
present in foundry wastewater. Pesticide concentrations were not
confirmed by mass spectroscopy or multiple GC column techniques.
False positive results can be common when confirmation is not
performed. The gas chromatography (GC) spectra and retention
time for several pesticides is very similar to those of the PCB's
which were detected in aluminum die casting water. EPA believes
the spectra for the PCB's, which were present in the water at the
time of sampling, created a "false-positive" for the pesticides.
Pesticides are not believed to be present in aluminum foundry
wastewaters, and are thus excluded from regulation.
Priority Pollutants Present Below Concentrations Achievable by
Treatment
The pollutants listed below are not considered further for
regulation because they were not found in any wastewater samples
from this subcategory above concentrations considered achievable
by existing or available treatment technologies or are not
believed to be currently present at treatable concentrations:
278
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106. PCB-1242 112. PCB-1016
107. PCB-1254 115. arsenic
108. PCB-1221 119. chromium
109. PCB-1232 121. cyanide
110. PCB-1248 123. mercury
111. PCB-1260 124. nickel
PCB's (pollutants 106 through 112) were detected in some samples
of aluminum casting wastewater collected in 1978, predominantly
in aluminum die casting wastewater. Eight of 10 die casting
samples collected in 1978 contained PCB's. In 1978, PCB's were a
common component of hydraulic fluids used in die casting
operations. Hydraulic fluid leakage is included in die casting
wastewater discharges. However, Section 6(e) of the Toxic
Substances Control Act {TSCA) generally prohibits the use of
PCB's after January 1, 1978. EPA promulgated a rule, which was
published in the Federal Register of May 31, 1979 {44 FR 31514),
to implement Sections 6{e)(2) and (3) of TSCA. This rule is
listed in the Code of Federal Regulations under 40 CFR Part 761.
The use of PCB's in hydraulic systems is governed by 40 CFR
761.30(e). That part requires the annual monitoring and flushing
of PCB-bearing hydraulic systems, beginning no later than
November 1, 1979, until the concentration of PCB's in the
hydraulic system is below 50 ppm. Data available to the Agency
indicate that when PCB-bearing oil systems (transformers) are
flushed and refilled with non-PCB-bearing oils, PCB
concentrations in the system are reduced by over 90 percent.
Because PCB's are no longer used in process fluids associated
with die casting operations, and because EPA has observed that
when the use of PCB's is discontinued, and required flushing
takes place, the presence of PCB's is reduced by greater than 90
percent during each occurrence of flushing, PCB's are not
expected to be currently present in die casting wastewaters at
treatable concentrations.
PCB's were also detected in 1978 at low levels in the melting
furnace scrubber wastewater at plant 17089. The make-up water to
the scrubber consisted of treated effluent that contained some
treated die casting wastewater. The scrubber make-up water
contained low levels of PCB's similar to those found in the
melting furnace scrubber wastewater. EPA. believes the presence
of PCB's in the melting furnace scrubber water can be attributed
to the die casting operations at plant 17089 and are not related
to melting furnace scrubber operations.
PCB's were detected in one waste stream at an aluminum investment
casting plant (plant 04704, sample point B). The source of the
PCB's in the investment casting process is unconfirmed, although
the levels of PCB's detected at plant 04704 may be related to
hydraulic fluid leakage from the ram used in the mold back-up
station at that facility.
The presence of PCB's in aluminum casting wastewaters sampled in
1978 is attributed to the presence of PCB-bearing hydraulic fluid
in wastewater. The use of PCB's in hydraulic fluids has
279
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subsequently been controlled by Section 6(e) of TSCA and the
Agency does not expect PCB's to currently be present in aluminum
casting wastewaters at treatable concentrations. Therefore, EPA
is not considering PCB's for regulation in the aluminum
subcategory.
Priority Pollutants Detected rn the Effluent From Only a gmaljl
Number o_f_ Sources
The priority pollutants listed below are not considered further
for regulation because they were detected in the effluent from
only a small number of sources and they are uniquely related to
only those sources, EPA is considering a pollutant detected in
the ratio of only one out of seven or more samples as being a
"small number of sources." Although national effluent
limitations guidelines or standards are not specified for these
pollutants, it may be appropriate for the individual permitting
authority or municipality to specify limits for these compounds
if they are reported on permit applications at levels above
treatability. The permit writers will make these determinations
on a case-by-case basis.
5. benzidine 57.
6. carbon tetrachloride 58.
10. 1,2-dichloroethane 59.
13. 1,1-dichloroethane 60.
15. 1,1,2,2-tetrachloroethane 62.
18. bis(chloroethyl) ether 63.
24. 2-chlorophenol 64.
31. 2,4-dichlorophenol 71.
38. ethylbenzene 77.
48. dichlorobromomethane
2-nitrophenol
4-nitrophenol
2,4-dinitrophenol
4,6-dinitro-o-cresol
N-nitrosodiphenylamine
N-nitrosodi-n-propylamine
pentachlorophenol
dimethyl phthalate
acenaphthylene
Priority Pollutants Selected for Further Consideration in
Establishing Effluent Limitations Guidelines and Standards
Based on the analyses described above, the pollutants listed
below were selected for further consideration for regulation in
this subcategory:
1. acenaphthene
4. benzene
7. chlorobenzene
11. 1,1,1-trichloroethane
21. 2,4,6-trichlorophenol
22. para-chloro-meta-cresol
23. chloroform
34. 2,4-dimethylphenol
39. fluoranthene
44. methylene chloride
55. naphthalene
65. phenol
66. bis(2-ethylhexyl)
phthalate
67. butyl benzyl phthalate
68. di-n-butyl phthalate
70. diethyl phthalate
72. benzo{a)anthracene
73. benzo^ajpyrene
76. chrysene
78. anthracene
80. fluorene
81. phenanthrene
84. pyrene
85. tetrachloroethylene
86. toluene
87. trichloroethylene
120. coppe r
122. lead
128. zinc
280
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Pollutant Selection £or_ the Copper Subcategory
Conventional and Nonconventional Pollutant Parameters
Four conventional and nonconventional pollutant parameters were
selected for further consideration in this subcategory, and are
listed below:
oil and grease
total phenols (4-AAP)
total suspended solids (TSS)
Total phenols were only selected for further consideration in the
dust collection scrubber and melting furnace scrubber process
segments, because the average concentration of total phenol in
these process segments is above treatable levels.
Oil and grease, total phenols, and TSS are selected for further
consideration because they were each found in raw wastewater
samples in concentrations exceeding those achievable by
identified treatment technologies. Table VI-3 shows the
frequency of occurrence of these three parameters, along with the
range of pH values observed in this study. In addition, these
three pollutant parameters are expected to be present in the raw
wastewater based on their presence in the raw materials and
production processes employed by the plants in this subcategory.
Furthermore, limitations on oil and grease, total phenols, and
TSS ensure effective removal of priority organic and precipitated
metal pollutants because these bulk parameters provide a good
indication of overall treatment system performance. Oil and
greaser total phenols, and TSS are commonly regulated in existing
permits.
The 11 pH values measured in copper subcategory wastewater ranged
from 7.0 to 8.4. Review of pH data can be an effective means of
determining whether a treatment system is operating properly.
Effective removal of metal pollutants by chemical treatment
requires careful control of pH; the control of pH to within
desirable limits is readily achievable in this subcategory.
Therefore, pH was selected for further consideration for
regulation.
Priority Pollutants
The frequency of occurrence of the priority pollutants for the
copper subcategory is presented in Table VI-4 at the end of this
section. That table is based on data for the raw wastewater from
three process segments - direct chill casting, mold cooling, and
dust collection scrubber. The following discussion is based on
information included in Table VI-4.
281
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Priority Pollutants Never Detected or Never Found Above Their
Analytical Quantification Concentration
The priority pollutants listed below were not detected or found
above their analytical quantification concentration in any
wastewater samples from this subcategory, nor is there any reason
to expect them to be present in the wastewater based on the
Agency's review of raw materials and production processes
employed; therefore, they are not considered further for
regulation:
2. acrolein 53.
3. acrylonitrile
4. benzene 54.
5. benzidine 56.
7. chlorobenzene 59.
8. 1,2,4-trichlorobenzene 60.
9. hexachlorobenzene 61.
10. 1,2-dichloroethane . 62.
12. hexachloroethane 63.
13. 1,1-dichloroethane
15. 1,1,2,2-tetrachloroethane 79.
16. chloroethane 80.
17. bis(chloromethyl) ether 82.
(deleted) 83.
18. bis(2-chloroethyl) ether 86.
19. 2-chloroethyl vinyl ether 88.
20. 2-chloronaphthalene 89,
24. 2-chlorophenol 90.
25. 1,2-dichlorobenzene 91.
26. 1,3-dichlorobenzene 92.
27, 1,4-dichlorobenzene 93.
28. 3,3'-dichlorobenzidine 94.
29. 1,1-dichloroethylene 95.
30. 1,2-trans-dichloro- 96.
ethylene 97,
31. 2,4-dichlorophenol 98.
32. 1,2-dichloropropane 99.
33. 1,2-dichloropropylene 100.
35. 2,4-dinitrotoluene 101.
37. 1,2-diphenylhydrazine 102.
38. ethylbenzene 103.
39. fluoranthene 104.
40. 4-chlorophenyl phenyl 105.
ether 106,
41. 4-bromophenyl phenyl ether 107.
42. bis(2-chloroisopropyl) 108,
ether 109.
43. bis(2-chloroethoxy) ether 110.
44, methylene chloride 111.
46. methyl bromide 112.
47, bromoform 113,
48. dichlorobromomethane 114.
49. trichlorofluoromethane 116.
(deleted) 117.
hexachlorocyclopenta-
diene
isophorone
nitrobenzene
2,4-dinitrophenol
4,6-dinitro-o-cresol
N-nitrosodimethylamine
N-nitrosodiphenylamine
N-nitrosodi-n-propyl-
amine
benzofghi)perylene
fluorene
dibenzo(a,h)anthracene
indeno(1,2,3-c,d)pyrene
toluene
vinyl chloride
aldrin
dieldrin
chlordane
4,4*-DDT
4,4'-DDE
4,4*-ODD
Alpha-endosulfan
Beta-endosulfan
endosulfan sulfate
endrin
endrin aldehyde
heptachlor
heptachlor epoxide
Alpha-BHC
Beta-BHC
Gamma-BHC
Delta-BHC
PCB-1242
PCB-1254
PCB-1221
PCB-1232
PCB-1248
PCB-1260
PCB-1016
toxaphene
antimony
asbestos
beryllium
282
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50. dichlorodifluoro-
methane (deleted)
51. chlorodibromomethane
52. hexachlorobutadiene
125. selenium
127. thallium
129. 2,3,7,8-tetrachlorodi-
benzo-p-dioxin (TCDD)
Priority
Treatment
Pollutants Present Below Concentrations Achievable by
The pollutants listed below are not considered further for
regulation because they were not found in any wastewater samples
from this subcategory above concentrations considered achievable
by existing or available treatment technologies:
115.
121.
123.
126.
arsenic
cyanide
mercury
silver
Priority Pollutants Detected in, the Effluent From
Number of Sources
Small
The priority pollutants listed below are not considered further
for regulation because they were detected in the effluent from
only a small number of sources. EPA is considering a pollutant
detected in the ratio of only one out of seven or more samples as
being a "small number of sources." Although national effluent
limitations guidelines or standards are not specified for these
pollutants, it may be appropriate for the individual permitting
authority or municipality to specify limits for these compounds
if they are reported on permit applications at levels above
treatability. The permit writers will make these determinations
on a case-by-case basis.
6. carbon tetrachloride
11. 1,1/1-trichloroethane
14. 1,1,2-trichloroethane
21. 2,4,6-trichlorophenol
36. 2,6-dinitrotoluene
45. methyl chloride
57.
69.
73.
85.
87.
2-nitrophenol
di-n-octyl phthalate
benzo(a)pyrene
tetrachloroethylene
trichloroethylene
Priority Pollutants Selected for Further Cons i de ra tion in
Establishing Effluent Limitations Guidelines and Standards
Based on the analyses described above, the pollutants listed
below were selected for further consideration for regulation in
this subcategory.
283
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1. acenaphthene
22. para-chloro-meta-cresol
23. chloroform
34. 2,4-dimethylphenol
55. naphthalene
58, 4-nitrophenol
64. pentachlorophenol
65. phenol
66. bis(2-ethylhexyl)
phthalate
67. butyl benzyl phthalate
68. di-n-butyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
72. benzo{a)anthracene
74. 3,4-benzof luoranthene
75. benzo{k)f luoranthene
76. chrysene
77. acenaphthylene
78. anthracene
81. phenanthrene
84. pyrene
118. cadmium
119. chromium
120. copper
122. lead
124. nickel
128. zinc
Pollutant Selection for the Ferrous Sub category
Conventional and Nonconventional Pollutant Parameters
Four conventional and nonconventional pollutant parameters were
selected for further consideration in this aubcategory, and are
listed below:
oil and grease
total phenols (4-AAP)
total suspended solids (TSS)
pH
Total phenols were only selected for further consideration in the
dust collection scrubber, melting furnace scrubber, and wet sand
reclamation process segments, because the average concentration
of total phenol in these process segments is above treatable
levels.
Oil and grease, total phenols, and TSS are selected for further
consideration because they were each found in raw wastewater
samples in concentrations exceeding those achievable by
identified treatment technologies. Table VI-5 shows the
frequency of occurrence of these three parameters, along with the
range of pH values observed in this study. In addition, these
three parameters are expected to be present in the raw wastewater
based on their presence in the raw materials and production
processes employed by the plants in this subcategory.
Furthermore, limits on oil and grease/ total phenols, and TSS
ensure effective removal of priority organic and precipitated
metal pollutants because these bulk parameters provide a good
indication of overall treatment system performance. Oil and
grease, total phenols, and TSS are commonly regulated in existing
permits.
The 18 pH values measured in ferrous subcategory wastewater
ranged from 3.7 to 11. Review of pH data can be an effective
means of determining whether a treatment system is operating
properly. Effective removal of metal pollutants by chemical
treatment requires careful control of pH; the control of pH to
284
-------
within desirable limits is readily achievable in this
subcategory. Therefore, pH was selected for further
consideration for regulation.
Priority Pollutants
The frequency of occurrence of the priority pollutants for the
ferrous subcategory is presented in Table VI-6 at the end of this
section. That table is baaed on data for the raw wastewater from
seven process segments - casting cleaning, casting quench,
melting furnace scrubber/ slag quench, wet sand reclamation, mold
cooling, and dust collection scrubber. The following discussion
is based on information included in Table VI-6.
Priority Pollutants Never Detected o£ Never Found Above Thei_r_
Analytical Quantification^ Concentration
The priority pollutants listed below were not detected or found
above their analytical quantification concentration in any
wastewater samples from this subcategory, nor is there any reason
to expect them to be present in the wastewater based on the
Agency's review of raw materials and production processes
employed,* therefore, they are not considered further for
regulation:
2. acrolein 48.
3. acrylonitrile 49.
5. benzidene
6. carbon tetrachloride 50.
7, chlorobenzene
8. l,2,4-trichloroben2ene 51.
9. hexachlorobenzene 52.
10. 1,2-dichloroethane 53.
12. hexachloroethane 61.
13. 1,1-dichloroethane 63.
14. 1,1,2-trichloroethane 73.
15. 1,1,2,2-tetrachloroethane 79.
16. chloroethane 82.
17. bis(chloromethyl) ether 83.
(deleted) 88.
18. bis(2-chloroethyl) ether 89.
19. 2-chloroethyl vinyl ether 90.
21. 2,4,6-trichlorophenol 91.
25. 1,2-dichlorobenzene 92.
26. 1,3-dichlorobenzene 93.
27. 1,4-dichlorobenzene 94.
28. 3,3'-dichlorobenzidine 95.
29. 1,1-dichloroethylene 96.
32. 1,2-dichloropropane 97.
33. 1,3-dichloropropylene 98,
37. 1,2-diphenylhydrazine 100.
38, ethylbenzene 101,
40. 4-chlorophenyl phenyl 102.
ether 103.
41. 4-bromophenyl phenyl ether 104.
dichlorobromomethane
trichlorofluoromethane
(deleted)
dichlorodifluoromethane
(deleted)
chlorodibromomethane
hexachlorobutadiene
hexachlorocyclopentadiene
N-nitrosodimethylamine
N-nitrosodi-n-propylamine
benzo(a)pyrene
benzo(ghi)perylene
dibenzo(a,h)anthracene
indeno(l,2,3-c,d)pyrene
vinyl chloride
aldrin
dieldrin
chlordane
4,4'-DDT
4,4'-DDE
4,4'-ODD
Alpha-endosulfan
Beta-endosulfan
endosulfan sulfate
endrin
heptachlor
heptachlor epoxide
Alpha-BHC
Beta-BHC
Gamma-BHC
285
-------
42. bis(2-chloroisopropyl
ether
45. methyl chloride
46. methyl bromide
47. bromoform
105. Delta-BHC
113, toxaphene
116. asbestos
129, 2,3,7,8-tetrachlorodi-
benzo-p-dioxin (TCDD)
Priority
Treatment
Pollutants Present Below Concent rat ions Achievable by
The pollutants listed below are not considered further for
regulation because they were not found in any wastewater samples
from this subcategory above concentrations considered achievable
by existing or available treatment technologies:
20. 2-chloronaphthalene
115. arsenic
117. beryllium
121. cyanide
123.
126.
127.
mercury
silver
thallium
Priority Pollutants Detected in the Effluent From
Number of Sources
Small
The priority pollutants listed below are not considered further
for regulation because they were detected in the effluent from
only a small number of sources and they are uniquely related to
only those sources. EPA is considering a pollutant detected in
only one out of seven or more samples as being a "small number of
sources." Although national effluent limitations guidelines or
standards are not specified for these pollutants, it may be
appropriate for the individual permitting authority or
municipality to specify limits for these compounds if they are
reported on permit applications at levels above treatability.
The permit writers will make these determinations on a case-by-
case basis.
4, benzene 62.
11. 1,1,1-trichloroethane 69.
22. para-chloro-meta-cresol 74.
24. 2-chlorophenol 75.
30. 1,2-trans-dichloro- 85.
ethylene 86.
35. 2,4-dinitrotoluene 87.
36. 2,6-dinitrotoluene 99.
43. bis(2-chloroethoxy) 106.
methane 107.
54, isophorone 108.
56. nitrobenzene 109.
57. 2-nitrophenol 110.
58. 4-nitrophenol 111.
59. 2,4-dinitrophenol 112.
60. 4,6-dinitro-o-cresol
N-nitrosodiphenylamine
di-n-octyl phthalate
3 r4-benzofluoranthene
benzo{k)fluoranthene
tetrachloroethylene
toluene
trichloroethylene
endrin aldehyde
PCB-1242
PCB-1254
PCB-1221
PCB-1232
PCB-1248
PCB-126Q
PCB-1016
PCS's were found in samples of melting furnace scrubber water
collected in 1978 at one ferrous foundry (plant 06956). However,
in 1985, additional samples taken at this facility showed PCB's
286
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to no longer be present in the wastewater. The 1978 sampling
data showing the presence of PCB's in plant 06956 melting furnace
scrubber water was not included in the development of Table VI-6,
and was not considered in the selection of pollutants for
regulatory consideration, because it was not confirmed by the
analysis of samples collected in 1985.
Priority Pollutants Selected for Further^ Cons ide rat ioji iji
Establishing Effluejit Limitations Guide!Ines ajid Standards
Based on the analyses described above, the pollutants listed
below were selected for further consideration for regulation in
this subcategory.
1. acenaphthene
23. chloroform
31. 2,4-dichlorophenol
34. 2,4-dimethylphenol
39. fluoranthene
44. methylene chloride
55. naphthalene
64. pentachlorophenol
65. phenol
66. bis(2-ethylhexyl)
phthalate
67. butyl benzyl phthalate
68. di-n-octyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
72. benzo(a)anthracene
76. chrysene
77. acenaphthylene
78. anthracene
80. fluorene
81. phenanthrene
84. pyrene
114. antimony
118. cadmium
119. chromium
120. copper
122. lead
124. nickel
125. selenium
128. zinc
Pollutant Selection for the Magnesium Subcategory
Conventional and Nonconventional Pollutant Parameters
,*
Three conventional and nonconventional pollutant parameters were
selected for further consideration in this subcafcegory, and are
listed below:
oil and grease
total suspended solids (TSS)
pH
As discussed in Sections IX and X, the magnesium subcategory is
excluded from regulation because regulatory options considered
for the magnesium subcategory are economically unachievable.
Therefore/ oil and grease, TSS, and pH are not limited in this
subcategory.
Oil and grease and TSS were considered for regulation because
they were each found in raw wastewater samples in concentrations
exceeding those achievable by identified treatment technologies.
Table VI-7 shows the frequency of occurrence of these two
parameters observed in this study. In addition, these parameters
are expected to be present in the raw wastewater based on their
presence in the raw materials and production processes employed
287
-------
by the plants in this subcategory. Furthermore, limits on oil
and grease and TSS ensure effective removal of priority organic
and precipitated metal pollutants because these bulk parameters
provide a good indication of overall treatment system
performance. Oil and grease and TSS are commonly regulated in
existing permits.
The pH was not measured in any wastewater sample in this
subcategory. However, review of pH data can be an effective
means of determining whether a treatment system is operating
properly. Effective removal of metal pollutants by chemical
treatment requires careful control of pH; the control of pH to
within desirable limits is readily achievable in this
subcategory. Therefore, pH was considered for regulation in the
magnesium subcategory.
Priority Pollutants
The frequency of occurrence of the priority pollutants for the
magnesium subcategory is presented in Table VI-8 at the end of
this section. That table is based on data for the raw wastewater
from one process segment - grinding scrubber. The following
discussion is based on information included in Table VI-8.
Priority Pollutants Never Detected or Never Found Above Their
Analytical^}uantificatIon Concentration
The priority pollutants listed below were not detected or found
above their analytical quantification concentration in any
wastewater samples from this subcategory, nor is there any reason
to expect them to be present in the wastewater based on the
Agency's review of raw materials and production processes
employed; therefore, they are not considered further for
regulation:
1. acenaphthene 63.
2. acrolein 64.
3. acrylonitrile 65.
4, benzene 67.
5. benzidene 68.
6. carbon tetrachloride 69.
7. chlorobenzene 70.
8. 1,2,4-trichlorobenzene 71.
9, hexachlorobenzene 72.
10. 1,2-dichloroethane 73.
11. 1,1,1-trichloroethane 74.
12. hexachloroethane 75.
13. 1,1-dichloroethane 76.
14. 1,1,2-trichloroethane 77.
15. 1,1,2,2-tetrachloroethane 78.
16. chloroethane 79.
17. bis{chloromethyl) ether 80,
18. bis{2-chloroethyl) ether 81.
19. 2-chloroethyl vinyl ether 82.
20. 2-chloronaphthalene 83.
N-nitrosodi-n-propylatnine
pentachlorophenol
phenol
butyl benzyl phthalate
di-n-butyl phthalate
di-n-octyl phthalate
diethyl phthalate
dimethyl phthalate
benzo(a)anthracene
benzo(a)pyrene
3,4-benzofluoranthene
benzo{k)fluoranthene
chrysene
acenaphthylene
anthracene
benzo(ghi)perylene
fluorene
phenanthrene
dibenzo{a,h)anthracene
indeno(l,2,3-c,d)pyrene
288
-------
21, 2f4,6-trichlorophenol 84.
22. para-chloro-meta-cresol 85.
23. chloroform 86.
24, 2-chlorophenol 87,
25. 1,2-dichlorobenzene 88.
26. 1,3-dichlorobenzene 89,
27. 1,4-dichlorobenzene 90.
28. 3,3'-dichlorobenzidine 91.
29. 1,1-dichloroethylene 92.
30. 1,2-trans-dichloroethylene 93.
31. 2,4-dichlorophenol 94,
32, 1,2-dichloropropane 95.
33. 1,3-dichloropropylene 96,
34. 2,4-dimethylphenol 97.
35. 2,4-dinitrotoluene 98.
36. 2,6-dinitrotoluene 99.
37. 1,2-diphenylhydrazine 100,
38. ethylbenzene 101.
39. fluoranthene 102.
40. 4-chlorophenol phenyl 103.
ether 104.
41. 4-bromophenyl phenyl ether 105.
42. bis{2-chloroisopropyl) 106.
ether 107.
43. bis(2-chloroethoxy)methane 108.
45. methyl chloride 109.
46. methyl bromide 110.
47. bromoform 111.
48. dichlorobromomethane 112.
49. trichlorofluoromethane 113.
(deleted) 114.
50. dichlorodifluoromethane 115.
(deleted) 116.
51. chlorodibromomethane 117,
52. hexachlorobutadiene 118.
53. hexachlorocyclopentadiene 119.
54. isophorone 120.
55. naphthalene 122.
56. nitrobenzene 123.
57. 2-nitrophenol 124.
58. 4-nitrophenol 125.
59. 2,4-dinitrophenol 126.
60. 4,6-dinitro-o-cresol 127.
61. N-nitrosodimethylamine 129.
62. N-nitrosodiphenylamine
pyrene
tetrachloroethylene
toluene
trichloroethylene
vinyl chloride
aldrin
dieldrin
chlordane
4,4'-DDT
4,4'-DDE
4,4*-ODD
Alpha-endosulfan
Beta-endosulfan
endosulfan sulfate
endrin
endrin aldehyde
heptachlor
heptachlor epoxide
Alpha-BHC
Beta-BBC
Gamma-BHC
Delta-BHC
PCB-1242
PCB-1254
PCB-1221
PCB-1232
PCB-1248
PCB-1260
PCB-1016
toxaphene
antimony
arsenic
asbestos
beryllium
cadmium
chromium
copper
lead
mercury
nickel
selenium
silver
thallium
2,3,7,8-tetrachlorodi-
benzo-p-dioxin (TCDD)
Priority
Treatment
Pollutants Present Below Concentrations Achievable by
The pollutant listed below is not considered further for
regulation because it was not found in any wastewater samples
from this subcategory above concentrations considered achievable
by existing or available treatment technologies:
121. cyanide
289
-------
Priority Pollutants Selected for^ Further Consideration in
Establishing Effluent Limitations Guidelines and Standards
Based on the analyses described above, the pollutants listed
below were selected for further consideration for regulation in
this subcategory,
44. methylene chloride
66. bis(2-ethylhexyl) phthalate
128. zinc
Pollutant Selection for the Zinc Subcategory
Conventional and Nonconventional Pollutant Parameters
Four conventional and nonconventional pollutants or pollutant
parameters were selected for further consideration in this
subcategory, and are listed below:
oil and grease
total phenols (4-AAP)
total suspended solids (TSS)
PH
Total phenols were only selected for further consideration in the
die casting and melting furnace scrubber process segments,
because the average concentration of total phenol in these
process segments is above treatable levels.
Oil and grease, total phenols, and TSS are selected for
limitations because they were each found in raw wastewater
samples in concentrations exceeding those achievable by
identified treatment technologies. Table VI-9 shows the
frequency of occurrence of these three parameters, along with the
range of pH values observed in this study. In addition, these
three pollutant parameters are expected to be present in the raw
wastewater based on their presence in the raw materials and
production processes employed by the plants in this subcategory.
Furthermore, limits on oil and grease, total phenols, and TSS
ensure effective removal of priority organic and precipitated
metal pollutants because these bulk parameters provide a good
indication of overall treatment system performance. Oil and
grease, total phenols, and TSS are commonly regulated in existing
permits.
The eight pH values measured in zinc subcategory wastewater
ranged from 5.7 to 7,5. Review of pH data can be an effective
means of determining whether a treatment system is operating
properly. Effective removal of metal pollutants by chemical
treatment requires careful control of pH; the control of pH to
within desirable limits is readily achievable in this
subcategory. Therefore, pH was selected for further
consideration for regulation.
290
-------
Priority Pollutants
The frequency of occurrence of the priority pollutants for the
zinc subcategory is presented in Table VI-10 at the end of this
section. That table is based on data for the raw wastewater from
two process segments - casting quench and die casting. The
following discussion is based on information included in Table
VI-10.
Priority Pollutants Never Detected ot_ Found Above TjTgij:
Analytical Quant ifleation Concentration
The priority pollutants listed below were not detected or found
above their analytical quantification concentration in any
wastewater samples from this subcategory nor is there any reason
to expect them to be present in the wastewater based on the
Agency's review of raw materials and production processes
employed? therefore, they are not considered further for
regulation.
2. acrolein 57.
3. acrylonitrile 60.
5. benzidene 61.
7« chlorobenzene 62.
8. 1,2,4-trichlorobenzene 63*
i, hexachlorobeniene 64.
10, 1,2-dichloroethane 71.
12. hexachloroethane 73.
13. Irl-dichloroethane 74.
14. 1,1,2-trichloroethane 75.
15. l,lf2,2-tetrachloroethane 77.
16. chloroethane 79.
17. bis{chloromethyl) ether 80.
18. bis(2~chloroethyl) ether 82.
19, 2-chloroethyl vinyl ether 83.
20. 2-chloronaphthalene 88.
25, 1,2-dichlorobenzene 89,
26, 1,3-dichlorobenzene 90.
27. 1,4-dichlorobenzene 91.
28. 3,3'-dichlorobenzidine 92.
29. 1,1-dichloroethylene 93.
32. 1,2-dichloropropane 94.
33. 1,3-dichloropropylene 95.
35. 2,4-dinitrotoluene 96.
35. 2,6-dinitrotoluene 97.
37, 1,2-diphenylhydrazine 98.
40. 4-chlorophenol phenyl 99.
ether 100.
41. 4-bromophenyl phenyl ether 101.
42. bis{2-chloroisopropyl) 102.
ether 103.
43, bis(2-chloroethoxy)methane 104.
45. methyl chloride 105.
46. methyl bromide 113.
47, bromoform 114.
2-nitrophenol
4,6-dinit -o-cresol
N-nitrosodimethylamine
N-nitrosodiphenylamine
N-nitrosodi-n-propylamine
pentachlorophenol
dimethyl phthalate
benmo{a)pyrene
3,4-benzofluoranthene
benzo(k)fluoranthene
acenaphthylene
benzo(ghi)perylene
fluorene
dibenzo(arh)anthracene
indeno{11213-c,d)pyrene
vinyl chloride
aldrin
dieldrin
chlordane
4,4'-DDT
4,4*-DDE
4r4'-DDD
Alpha-endosulfan
Beta-endosulfan
endosulfan sulfate
endrin
endrin aldehyde
heptachlor
heptachlor epoxide
Alpha-BHC
Beta-BHC
Gamma-BHC
Delta-BHC
toxaphene
antimony
291
-------
48. dichlorobromomethane 115. arsenic
49. trichlorof luoromethane 116, asbestos
(deleted) 117. beryllium
50. dichlorodif luoromethane 118. cadmium
(deleted) • 119. chromium
51. chlorodibromomethane 125. selenium
52. hexachlorobutadiene 126. silver
53. hexachlorocyclopentadiene 127. thallium
54. isophorone 129. 2,3, 7,8-tetrachlorodi-
56. nitrobenzene benzo-p-dioxin (TCDD)
Priority Pollutants Present Below Concentrations Achievable by_
Treatment
The pollutants listed below are not considered further for
regulation because they were not found in any wastewater samples
from this subcategory above concentrations considered achievable
by existing or available treatment technologies:
106. PCB-1242 111. PCB-1260
107. PCB-1254 112. PCB-1016
108. PCB-1221 121. cyanide
109. PCB-1232 123. mercury
110. PCB-1248 124. nickel
PCB's were detected in one sample of zinc die casting wastewater
collected in 1978. In 1978 , PCB's were a common component of
hydraulic fluids used in die casting operations. Hydraulic fluid
leakage is included in die casting wastewater discharges.
However, Section 6(e) of TSCA generally prohibits the use of
PCB's after January 1, 1978. EPA promulgated a rule, which was
published in the Federal Register of Hay 31, 1979 (44 PR 31514)
to implement Sections !T{e) (2) and (3) of TSCA. This rule is
listed in the Code of Federal Regulations under 40 CFR Part 716.
The use of PCB's in hydraulic systems is governed by 40 CPR
716. 30 (e). That part requires the annual monitoring and flushing
of PCB-bearing hydraulic systems, beginning no later than
November 1, 1979, until the concentration of PCB's in the
hydraulic system is below 50 ppm. Data available to the Agency
indicate that when PCB-bearing oil systems are flushed and
refilled with non-PCB-bearing oils, PCS concentrations in the
system are reduced by over 90 percent. Because PCB's are no
longer used in process fluids associated with die casting
operations, and because EPA has observed that when the use of
PCB's is discontinued, and required flushing takes place, the
presence of PCB's is reduced by greater than 90 percent during
each occurrence of flushing, PCB's are not expected to be
currently present in die casting wastewaters at treatable
concentrations.
Pollutants Detected .in the Sff luen t From Only a Small
NumbeYof Sources
The priority pollutants listed below are not considered further
for regulation because they were detected in the effluent from
292
-------
only a small number of sources. EPA is considering a pollutant
detected in the ratio of only one out of seven or more samples as
being a "small number of sources." Although national effluent
limitations guidelines or standards are not specified for these
pollutants, it may be appropriate for the individual permitting
authority or municipality to specify limits for these compounds
if they are reported on permit applications at levels above
treatability. The permit writers will make these determinations
on a case-by-case basis.
4. benzene 67.
6. carbon tetrachlorido 69.
11. 1,1,1-trichloroethane 72.
23. chloroform 76.
30. 1,2-trans-dichloroethylene 78,
38. ethylbenzene 81.
58. 4-nitrophenol 84.
59. 2,4-dinitrophenol
butyl benzyl phthalate
di-n-octyl phthalate
benzo(a)anthracene
chrysene
anthracene
phenanthrene
pyrene
Priority Pollutants Selected for Further Consideration in
Establishing Effluent Limitations Guidelines and Standards
Based on the analyses described above, the pollutants listed
below were selected for further consideration for regulation in
this subcategory.
1. acenaphthene
21. 2,4,6-trichlorophenol
22, para-chloro-meta-cresol
24. 2-chlorophenol
31, 2,4-dichlorophenol
34, 2,4-dimethylphenol
39. fluoranthene
44. methylene chloride
55. naphthalene
65, phenol
66,
68
70,
85,
86,
87-
120,
122,
128. zinc
bis(2-ethylhexyl}
phthalate
di-n-butyl phthalate
diethyl phthalate
tetrachloroethylene
toluene
trichloroethylene
copper
lead
293
-------
Table VI-1
FREQUENCY OF OCCURRENCE OF CONVENTIONAL AND NONCONVENTIONAL
POLLUTANT PARAMETERS IN THE ALUMINUM SUBCATEGORY
N)
'£>
Pollutant
Oil and Grease
Total Phenols
(4-AAP)
Total Suspended
Solids (TSS) .
pH
Number
of Samples
Treatable
Concentration
5
0.20
2.6
Number of
Samples
Analyzed
27
24
27
24
Detected Above
Treatable
Concentration
2H
9
26
Range of
Treatable
Conoentrationa
9-49,900 mg/1
1.07-25 mg/1
13-3,576 mg/1
5.4-8.7 standa
units
-------
Table VI-2
FREQUENCY OF OCCURRENCE OF THE PRIORITY POLLUTANTS
ALUMINUM SUBCATEGORY
Pollutant
1. acenaphthene
4. benzene
5. benzidene
6. carbon tetraehloride
7. chlorobenzene
10. 1,2-diehloroethane
11. 1,1,1-trichloroethane
13. 1,1-diehloroethane
15. 1,1,2,2-tetrachloroethane
IB. b!3{chloroethyl> ether
21. 2,1,6-lrlchlorophenol
22. para-chloro-meta-cresol
23. chloroform
24. 2-chlorophenol
31. 2,4-dichlorophenol
34. 2, 4-dimethylphenol
38. ethylbenzene
39. fluoranthene
14. methylene chloride
48. dichlorobrorcotnethane
55. naphthalene
57. 2-nitrophenol
58. 4-nitrophenol
59. 2,4-dinitrophenol
60. 4,6-dinitro-o-cresol
62. N-nitrosodiphenylamine
63. N-nitroaodl-n-propylamine
64. pentaohlorophenol
65. phenol
66. bisC2-ethylhexyl} phthalate
67. butyl benzyl phthalate
68. di-n-butyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
72. benzo(a)anthracene
73. benzo(a)pyrene
76. ehrysene
77. aoenaphthylene
78. anthracene
80. fluorene
81, phenanthrene
84. pyrene
85. tetraohloroethylene
Treatable
Concentration
fmg/I)
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
0.01
0.01
0.01
0.01
0.01
0.01
O.Of
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
0,01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
Number of
Samples
Analyzed
27
27
27
27
27
2?
27
27
27
27
27
27
27
27
27
27
27
27
27
27
27
27
27
27
27
27
2?
27
27
27
27
27
27
27
27
27
27
27
27
27
27
27
27
Not Detected
or Only
Detected Below
Quantification
Concentration
23
20
26
2«
23
25
19
26
25
26
16
22
7
24
2U
19
26
20
6
25
21
25
26
26
26
26
25
26
1U
0
21
16
20
25
23
23
21
24
23
23
23
18
13
Detected
Below
Treatable
Concentration
Detected
Above
Treatable
Cpncftntration
H
6
1
3
i)
1
7
1
t
J
11
5
20
2
3
6
1
7
18
2
5
2
1
1
1
1
2
1
13
27
6
11
7
2
H
3
6
3
2
K
2
9
12
-------
Table VI-2 (Continued)
FREQUENCY OF OCCURRENCE OF THE PRIORITY POLLUTANTS
ALUMINUM SUBCATEGORY
Pollutant
86.
87.
106.
107.
108.
109-
110.
111.
112.
115.
119.
120.
122.
123.
124.
128.
toluene
trichloroethylene
PCB-12H2
PCB-125t
PCB-1221
PCB-1232
PCB-1248
PCB-1260
PCB-1016
arsenic
chromium
copper
lead
mercury
nickel
zinc
Treatable
Concentration
Cmg/1)
0.01
0,01
0.01
0.01
0,01
O.Ot
0.01
0.0}
0.01
0.31*
0.07
0.17
0.15
0.036
0.22
0.18
Number of
Samples
Analyzed
27
2?
21
21
21
21
21
21
21
1
3
21
21
3
18
27
Kot Detected
or Orriy
Detected Below
Quantification
Detected
Below
Treatable
Concentration
22
11
9
9
9
8
8
8
8
1
3
9
15
3
1
2
7
2
3
3
7
Detected
Above
Treatable
Concentration
5
13
12
12
12
13
13
13
13
11
10
17
-------
Table VI-3
FREQUENCY OF OCCURRENCE OF CONVENTIONAL AND NONCONVENTIONAL
POLLUTANT PARAMETERS IN THE COPPER SUBCATEGORY
Pollutant
Oil and Grease
Total Phenols
C4-AAP)
Total Suspended
Solids (TSS)
PH
Treatable
Concentration
(me/1)
5
0.20
Number of
Samples
Analyzed
11
Number
of Samples
Detected Above
Treatable
Concentration
9
6
2.6
14
11
Range of
Treatable
9-110 rag/1
1.68-3.2T mg/1
16-35,000 rag/1
7.0-8.H standard
units
-------
Table VI-4
FREQUENCY OF OCCURRENCE OF THE PRIORITY POLLUTANTS
COPPER SUBCATEGORY
CD
Pollutant
1. acenaphthene
6. carbon tetrachloride
11. 1,1,1-trichloroethane
1H, 1,1,2-triohloroethane
21. 2,4,6-trichlorophenol
22, para-chloro-Bata-crvsol
23. chloroform
31. 2, H-dlinethyl phenol
36. 2,6-dinitretoluene
45. methyl chloride
55. naphthalene
57. 2-nitrophenol
58, it-nitrophenol
61. pentachlorophenol
65. phenol
66. bia(2-ethylheicyl) phthalate
67- butyl benzyl phthalate
68. dl-n-butyl phthalate
69- dl-n-octyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
72. benzo(a)anthracene
73. benzo(a)pyrene
74. Sj^-benzoflworanthene
75. banzo(k)fluoranthene
76, chryaene
77> acenaphthylene
78. anthracene
81. phenanthrene
8H. pyrene
85. tetrachloroethylen*
87. trlchlorqethylene
115. arsenic
118, cadmium
119. chromium
120. copper
122. lead
123- mercury
121. nickel
12S. silver
128. zinc
Treatable
Concentration
Cmg/I)
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
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
0,01
0,01
0.01
0.01
0.31
0.019
0.07
0.17
0.15
0.036
0.22
O.OT
0,18
number of
Samples
11
11
11
11
11
11
11
It
It
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
11
n
11
e
11
11
2
11
Hot Detected
or Only
Detected Below
Quantification
Concentuat ion
9
10
10
10
10
9
9
8
10
10
9
10
9
7
6
1
6
6
to
9
8
9
10
9
9
7
9
6
6
6
10
10
3
3
Detected
Below
Treatable
Concentration
Detected
Above
Treatable
on
2
1
1
1
1
1
2
3
1
1
S
I
2
3
5
i
i|
5
1
2
3
2
1
1
1
II
2
5
5
5
1
1
6
1
1!
10
5
14
-------
Table VI-5
FREQUENCY OF OCCURRENCE OF CONVENTIONAL AND NQNCQNVENTIONAL
POLLUTANT PARAMETERS IN THE FERROUS SUBCATEGORY
Pollutant
Parameter
Oil and Grease
Total Phenols
(4-AAP)
Total Suspended
Solids (TSS)
pH
Treatable
Concentration
(mg/1)
5
0.20
2.6
Number of
Samples
Analyzed
83
105
119
18
Number
of Samples
Detected Above
Treatable
Concentration
59
119
Range of
Treatable
Congejotrations
5.5-55 mg/1
0.24-59,5 rag/1
10-28,010 mg/1
3.7-11 standard
units
-------
Table VI-6
FREQUENCY OF OCCURRENCE OF THE PRIORITY POLLUTANTS
FERROUS SUBCATEGORY
Treatable
Concentration
UJ
o
o
1. acenaphthene
4. benzene
11. 1,1,1-trichloroethane
20. 2-chloronaphthalene
22. para-ehloro-tneta-creaol
23. chloroform
21. 2-chlorophenol
30. 1,2-trana-dichloroethylene
31. 2,4-dichlorophenol
31. 2,4-dlmethy1phenol
35. 2,4-dlnltrotoluene
36. 2,6-dinitrotoluene
39. fluoranthene
">3- bisO-chloroethoxy) methane
11. nethylene chloride
51. isophorone
55. naphthalene
56. nitrobenzene
57. 2-nltrophenol
58. 1-nitrophenol
59. 2,1-dlnitrophenol
60. 4,6-dlnitro-o-cresol
62. N-nitrosodiphenylamine
61. pentachlorophenol
65. phenol
66. bis(2-ethylheiyl) phthalate
67. butyl benzyl phthalate
68. di-n-butyl phthalate
69. dl-n-octyl phthalate
70. diethy1 phthalate
71. dimethyl phthalate
72. benzo(a)anthracene
71. 3i1-benzoriuoranthene
75. benzo(k)riuoranthene
76. chrysene
77. acenaphthylene
78. anthracene
01
01
01
01
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
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
0.01
01
01
0.01
0.01
0.
0.
Number of
Samples
Analyzed
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
Rot Detected
or Only
Detected Below
Quantification
36
17
H6
19
47
33
17
49
3«
22
Q8
48
26
48
27
46
33
48
46
48
19
19
45
31
17
16
38
23
48
29
20
12
49
19
31
38
22
Detected
Below
Treatable
Concentration
1
1
1
2
Detected
Above
Treatable
Conoentrati,Qn
13
2
^
3
15
3
1
16
28
2
2
21
2
23
1
16
2
M
2
1
1
5
19
32
31
12
27
2
21
29
8
1
1
14
10
24
-------
Table VI-6 (Continued)
OF OF THE PRIORITY POLLUTANTS
FERROUS
Treatable
Concentration
Pollutant
Number or
Samples
80.
81.
84.
85.
86.
87.
99.
106.
107.
100.
109.
110.
lit.
112.
lltt.
115.
117-
118.
lit.
120.
122,
123.
125.
126.
127.
128.
fluorene
phenanthrene
pyrene
tetraohloroelhylene
toluene
triehloroethylene
tndrin aldehyde
PCB-12M2
PCB-1254
PCB-1221
PCB-1232
PCB-1218
PCB-1260
PCB-1016
antimony
arsenic
beryllium
cadmium
chromium
copper
lead
mercury
selenium
silver
thallium
zinc
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
0.47
0.3*
0.20
0.049
0.07
0.07
15
0.036
0.22
0.20
0.07
0.3«
0.26
0
50
50
50
50
50
50
28
25
25
25
25
25
25
25
60
63
55
22
67
89
99
12
94
12
16
2
101
Mot Detected
or Only
Detected Below
Quantification
Concentration,
36
22
2H
15
27
24
24
24
2*
24
24
21
37
27
46
6
17
7
'16
13
25
Detected
Below
Treataole
Concentration
1
u
17
36
9
if
20
13
20
29
56
9
10
2
23
Detected
Above
Treatable
Concentration
13
21
26
f,
1
5
1
1
1
1
1
1
1
1
6
12
30
69
63
11
3
78
-------
LO
O
to
Table VI-7
FREQUENCY OF OCCURRENCE OF CONVENTIONAL AND NONCONVENTIONAL
POLLUTANT PARAMETERS IN THE MAGNESIUM SUBCATEGORY
Pollutant
Oil and Grease
Total Suspended
Solids (TSS)
Treatable
Concentration
(mg/1)
5
2.6
Number of
Samples
Analyzed
3
3
Number
of Samples
Detected Above
Treatable
QOflC 3 Q t j~g t^ 0 FL
1
3
Range of
Treatable
Concentrations
11 mg/1
10-63 mg/1
-------
Table VI-8
FREQUENCY OF OCCURRENCE OF THE PRIORITY POLLUTANTS
MAGNESIUM SUBCATEGORY
Hot Detected
or Only Detected Detected
Treatable Number of Detected Below Below Above
Concentration Samples Quantification Treatable Treatable
Pollutant (ma/1 J AoaJyjjed Co fiepnfcr^tip (L Concentration Concentration
11. methylene chloride 0.01 3 1 2
66. bis(2-elhylhexyl) phthalate 0.01 3 1 2
128. zinc 0,18 3 3
-------
UJ
o
Table VI-9
FREQUENCY OF OCCURRENCE OF CONVENTIONAL AND NONCONVENTIONAL
POLLUTANT PARAMETERS IN THE ZINC SUBCATEGORY
Number
of Samples
Treatable Number of Detected Above Range of
Pollutant Concentration Samples Treatable Treatable
Parameter (mg/1) Analyzed Concentration Concentrations
Oil and Grease 5 88 19-17,100 mg/1
Total Phenols 0.20 8 2 0.266-1.42 mg/1
O-AAP)
Total Suspended 2,6 8 8 8-3,800 mg/1
Solids (TSS)
pH 8 5.7-7.5 standard
units
-------
Table VI-10
FREQUENCY OF OCCURRENCE OF THE'PRIORITY POLLUTANTS
ZINC SUBCATEGORY
1, acenaphthene
1, benzene
6, carbon tetrachloride
11. 1,1,1-trlchloroethane
21. 2,4,6-trichlorophenol
22, para-chloro-meta-eresol
23- chloroform
21. 2-chlorophenol
30. 1r2-trana-dichloroethylene
31. 2,4-dichlorophenol
31. 2,4-dimethylphenol
38. ethylbenzene
39. fluoranthene
11. methylene chloride
55. naphthalene
58. 1-nitrophenol
59. 2t«-dinitrophenol
65. phenol
66. bis(2-ethyihexyl) phthalate
67. butyl benzyl phthelate
68. di-n-butyl phthelate
69. di-n-octyl phthalate
70. dlethyl phthalate
72. benxo(a)anthracene
76. chrysene
76. anthracene
61, phenanthrene
81. pyrcne
85. tetrachloroethyiene
B6. toluene
87. trionloroethylene
106. PCfl-1242
107. PCB-1251
108. PCB-1221
109. PCB-1232
110. PCB-t218
111. PCB-1260
112. PCB-1016
120. copper
122. lead
123. mercury
124. nickel.
128. zinc
Treatable
Concentration
(atg/11
0.01
o.ot
0.01
O.Of
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.01
o.ot
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
0.01
o.ot
0.01
0.01
0.01
0.01
0.01
0.01
0.0?
0.01
0.01
0.17
0.15
0.036
0.22
0.18
Number oT
Samples
Analyzed
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
fl
it
Not Detected
or Only
Detected Beloy
Quantification
Concentration
6
7
7
7
1
«l
7 '
6
7
«l
1
7
5
5
6
7
7
3
0
7
3
7
»l
7
7
T
7
7
3
6
6
3
3
3
3
3
3
3
Detected
Below
Treatable
Concentratton
1
Detected
Above
Treatable
Concentratton
1
1
1
1
M
>t
1
Z
1
2
M
1
3
2
2
1
1
5
8
1
5
1
3
1
1
1
1
1
5
2
2
\
1
1
1
1
1
1
1
3
-------
Table VI-11
ORGANIC PRIORITY POLLUTANTS CONSIDERED FOR REGULATION IN EACH PROCESS
ALUMINUM SUBCATEGORY
Pollutant
1. acenaphthene
4. benzene
7. chlorobenzene
11. 1,1,1-trlchloroethane
21. 2,1,6-trichlorophenol
22. para-chloro-meta-eresol
23. chloroform
31. 2,4-dimethylphenol
39. fluoranthene
44. methylene chloride
55. naphthalene
65. phenol
66. bis(2-etnylhexyl) phthalate
67. butyl benzyl phthalate
68. di-n-butyl phthalate
70. diethyl phthalate
72, benzoCa)anthracene
73. benzo(aJpyrene
76. chrysene
76. anthracene
80, Tluorene
81. phenanthrene
84. pyrene
85. tetrachloroethylene
86. toluene
87. triohloroethylene
Casting Casting
Cleaning Quench
X
X
X
X
X
X
X
X
X
X
X
X
X
Die
Casting
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Dust
Collection Gri.iJine
Scrubber Scrubber
X
X
X
X
X
X
X
X
X
X
X
X
CasLinn
Melting
Furnace Hold
Scrubber COD!ina
-------
Table VI-12
ORGANIC PRIORITY POLLUTANTS CONSIDERED FOR REGULATION IN EACH PROCESS
COPPER SUBCATEGORY
Pollutant
1. acenaphthene
22, para-chloro-mets-cresol
23. chloroform
3«. 2,i|-dlinethylphenol
55. naphthalene
58. H-nitrophenol
64. pentachlorophencrl
65. phenol
66. bis<2-ethylheiyl) phthalate
67. butyl benzyl phthalate
68. dl-n-butyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
72. benzo(a)anthracen«
7«. 3,it-benxcrfluoranthene
75. benzo
-------
Table VI-13
ORGANIC PRIORITY POLLUTANTS CONSIDERED FOR'REGULATION IN EACH PROCESS
FERROUS SUBCATEGORY
o
03
£Qi
t.
23-
31.
34.
39.
11.
55.
61.
65.
66.
67.
68.
70.
71.
72.
76.
77.
78.
SO.
81.
84.
Casting
lutaryt Qlean^ng
acenaphthene
chloroform
2,4-dichloro-
phenol
2,4-dimethyl-
phenol
fluoranthene
methylene chlo-
ride
naphthalene
pen tachloro-
phenol
phenol
bia(2-.ethyl-
hexyl)
phthalate
butyl benzyl
phthalate
dl-n-butyl
phthalate
dlethyl
phthalate
dimethyl
phthalate
benzo(a)anthra-
cene
chrysene
acenaphthylene
anthracene
Cluorene
phenanthrene
pyrene
Dust
Casting Collection Grinding
2ue_nfitl_ Scrubber Scrubber
X
X X
X
X I
X
I
X
X
X
X
X
X
I
X
X
X
X
X
X
X
X
Heltlng
Investment Furnace
Casting Scrubber
X X
X
X
X
X X
X
X
X X
X
X
X
X
X TL
X
X
X
X X
Hold Slag Wet Sand
Cooling Quench Reclamation
X
X
XXX
X
X
X
X
X
X
X
X X
X
X
X
-------
Table VI-1
ORGANIC PRIORITY POLLUTANTS CONSIDERED FOR REGULATION IN' EACH PROCESS SEGMENT
MAGNESIUH SUBCATEGORY
Pollutant
44. methylene chloride
66. bis(2-ethylhexyl) phthalate
Dust
Casting
Quepch
X
X
Collection
Scrubber
X
X
Grinding
Scrubber
X
X
-------
Table VI-15
ORGANIC PRIORITY POLLUTANTS CONSIDERED FOR REGULATION IN EACH PROCESS SEGMENT
ZINC SUBCATEGORY
UJ
)-•
o
Pollutant
1. acenaphthene
21. 2,4,6-trichlorophenol
22. para-chloro-meta-cresol
24. 2-chlorophenol
31. 2,4-dichlorophenol
34. 2,4-dlmethylphenol
39. fluoranthene
44. methylene chloride
55. naphthalene
65. phenol
66. bis(2-ethylhexyl) phthalate
68. di-n-butyl phthalate
70. dlethyl phthalate
85. tetrachloroethylene
86. toluene
87. trichloroethylene
Casting
Quench
X
X
X
X
X
X
X
X
X
X
X
Die
X
X
X
X
X
X
X
X
X
X
X
X
X
Melting
Furnace
Scrubber
Hold
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
INTRODUCTION
This section describes the treatment techniques currently used or
available to remove or recover wastewater pollutants normally
generated by the metal molding and casting industrial point
source category {also referred to a3 foundries). Included are
discussions of individual end-of-pipe treatment technologies and
in-plant technologies. These treatment technologies are widely
used in many industrial categories, and data and information to
support their effectiveness has been drawn from a similarly wide
range of sources and data bases.
Section VII discusses the treatment effectiveness concentrations
that can be expected with the application of these technologies.
Also discussed in Section VII are the options considered for the
BPT and BAT treatment trains for the metal molding and casting
industry.
END-OF-PIPE TREATMENT TECHNOLOGIES
Individual recovery and treatment technologies are described
which are used or are suitable for use in treating wastewater
discharges from metal molding and casting plants. Each
description includes a functional description and discussion of
applications, advantages and limitations, operational factors
(reliability, maintainability, solid waste aspects), and
demonstration status. The treatment processes described include
both technologies presently demonstrated within the category, and
technologies demonstrated in treatment of similar wastes in other
industries.
Metal molding and casting wastewaters characteristically tend
toward neutral pH; may contain substantial levels of TSS and
dissolved or particulate metals including copper, lead, and zincj
may contain substantial levels of toxic organic pollutants and
total phenol (4-AAP); and are generally free from strong
chelating agents. Oils and emulsions are also present in waste
streams emanating from several metal molding and casting
operations.
In general, these pollutants can be removed by oil removal
(skimming and emulsion breaking), permanganate oxidation,
chemical precipitation and sedimentation, which may be followed
by filtration. Most metals may be removed effectively by
precipitation as metal hydroxides or carbonates utilizing the
reaction with lime, sodium hydroxide, or sodium carbonate. Most
organics, including phenol, can be removed effectively by oil
removal in conjunction with chemical precipitation and
sedimentation. Permanganate oxidation also can be employed to
311
-------
reduce effectively phenol and toxic organic concentrations.
Discussion of end-of-pipe treatment technologies is divided into
two parts: the major technologies; and minor end-of-pipe
technologies,
MAJOR TECHNOLOGIES
Later in this section, the development of treatment systems
(options) is discussed. The individual technologies used in the
systems are described here. The major end-of-pipe technologies
for treating metal molding and casting wastewaters are:
1. Carbon adsorption,
2. Chemical precipitation,
3. Emulsion breaking,
4. Granular bed filtration,
5. Oxidation by potassium permanganate,
6. Pressure filtration,
7. Settling,
8. Skimming, and
9. Vacuum filtration.
In practice, precipitation of metals and settling of the
resulting precipitates is often a unified two-step operation.
Suspended solids originally present in raw wastewaters are not
appreciably affected by the precipitation operation and are
removed with the precipitated metals in the settling operations.
Settling operations can be evaluated independently of hydroxide
or other chemical precipitation operations, but hydroxide and
other chemical precipitation operations can only be evaluated in
combination with a solids removal operation.
The demonstration status of several of the major treatment
technologies is presented in Table VII-1. This table indicates
for each technology the number plants in the metal molding and
casting data base that reported the use of that technology in
their DCP.
I. Carbon Adsorption
The use of activated carbon to remove dissolved organics from
water and wastewater is a long demonstrated technology. It is
one of the most efficient organic removal processes available.
This sorption process is reversible, allowing activated carbon to
be regenerated for reuse by the application of heat and steam or
solvent. Activated carbon has also proved to be an effective
adsorbent for many toxic metals, including mercury. Regeneration
of carbon which has adsorbed significant amounts of metals,
however, may be difficult.
The term activated carbon applies to any amorphous form of carbon
that has been specially treated to give high adsorption
capacities. Typical raw materials include coal, wood, coconut
shells, petroleum base residues, and char from sewage sludge
312
-------
pyrolysis. A carefully controlled process of dehydration,
carbonization, and oxidation yields a product which is called
activated carbon. This material has a high capacity for
adsorption due primarily to the large surface area available for
adsorption, resulting from a large number of internal pores.
Pore sizes generally range from 10 to 100 angstroms in radius.
Activated carbon removes contaminants from water by the process
of adsorption, or the attraction and accumulation of one
substance on the surface of another. Activated carbon
preferentially adsorbs organic compounds and, because of this
selectivity, is particularly effective in removing organic
compounds from aqueous solution.
Carbon adsorption requires pretreatment to remove excess
suspended solids, oils, and greases. Suspended solids in the
influent should be less than 50 mg/1 to minimize backwash
requirements; a downflow carbon bed can handle much higher levels
(up to 2,000 mg/1) but requires frequent backwashing,
Backwashing more than two or three times a day is not desirable^
at 50 mg/1 suspended solids, one backwash will suffice. Oil and
grease should be less than about 10 mg/1. A high level of
dissolved inorganic material in the influent may cause problems
with thermal carbon reactivation (i.e., scaling and loss of
activity) unless appropriate preventive steps are taken. Such
steps might include pH control, softening, or the use of an acid
wash on the carbon prior to reactivation.
Activated carbon is available in both powdered and granular form.
An adsorption column packed with granular activated carbon is
shown in Figure VII-1. Powdered carbon is less expensive per
unit weight and may have slightly higher adsorption capacity, but
it is more difficult to handle and to regenerate.
Application. Isotherm tests have indicated that activated carbon
is very effective in adsorbing 65 percent of the organic priority
pollutants and is reasonably effective for another 22 percent.
Specifically, for the organics of particular interest, activated
carbon was very effective in removing 2,4-dimethylphenol,
fluoranthene, isophorone, naphthalene, all phthalates, and
phenanthrene. It was reasonably effective on 1,1,1-
trichloroethane, 1,1-dichloroethane, phenol, and toluene. Table
VII-2 summarizes classes of organic compounds together with
examples of organics that are readily adsorbed on carbon,
Advantages and Limitations. The major benefits of carbon
treatment include applicability to a wide variety of organics and
high removal efficiency. Inorganics such as cyanide, chromium,
and mercury are also removed effectively. Variations in
concentration and flow rate are tolerated well. The system is
compact, and recovery of adsorbed materials is sometimes
practical. However, destruction of adsorbed compounds often
occurs during thermal regeneration. If carbon cannot be
thermally desorbed, it must be disposed of along with any
adsorbed pollutants. The capital and operating costs of thermal
313
-------
regeneration are relatively high. Cost surveys show that thermal
regeneration is generally economical when carbon use exceeds
about 1,000 Ibs/day. Carbon cannot remove low molecular weight
or highly soluble organics. It also has a low tolerance for
suspended solids/ which must be removed to at least 50 mg/1 in
the influent water.
Operational Factors. Reliability: This system should be very
reliable with upstream protection and proper operation and
maintenance procedures.
Maintainability! This system requires periodic regeneration or
replacement of spent carbon and is dependent upon raw waste load
and process efficiency.
Solid Waste Aspects: iolid waste from this process is
contaminated activated carbon that requires disposal. Carbon
which undergoes regeneration reduces the solid waste problem by
reducing the frequency of carbon replacement.
Demonstration Status. Three metal molding and casting plants in
the metal molding and casting data base employ carbon adsorption
in wastewater treatment. Carbon adsorption systems have been
demonstrated to be practical and economical in reducing COD, BOD,
and related parameters in secondary municipal and industrial
wastewaters? in removing toxic or refractory organics from
isolated industrial wastewaters; in removing and recovering
certain organics from wastewaters; and in removing and some times
recovering selected inorganic chemicals from aqueous wastes,
Carbon adsorption is a viable and economic process for organic
waste streams containing up to 1 to 5 percent of refractory or
toxic organics. Its applicability for removal of inorganics such
as metals also has been demonstrated.
2, Chemical Precipitation
Dissolved toxic metal ions and certain anions may be chemically
precipitated for removal by physical means such as sedimentation,
filtration, or centrifugation. Several reagents are commonly
used to effect this precipitation:
(!) Alkaline compounds such as lime or sodium hydroxide may
be used to precipitate many toxic metal ions as metal
hydroxides. Lime also may precipitate phosphates as
insoluble calcium phosphate, fluorides as calcium
fluoride/ and arsenic as calcium arsenate.
(2) Both "soluble" sulfides such as hydrogen sulfide or
sodium sulfide and "insoluble" sulfides such as ferrous
sulfide may be used to precipitate many heavy metal
ions as metal sulfides,
(3) Ferrous sulfate, line sulfate or both (as is required)
may be used to precipitate cyanide as a ferro or zinc
ferricyanide complex.
314
-------
(4) Carbonate precipitates may be used to remove metals
either by direct precipitation using a carbonate
reagent such as calcium carbonate or by converting
hydroxides into carbonates using carbon dioxide.
These treatment chemicals may be added to a flash mixer or rapid
mix tank, to a presettling tank, or directly to a clarifier or
other settling device. Because metal hydroxides tend to be
colloidal in nature, coagulating agents may also be added to
facilitate settling. After the solids have been removed, final
pH adjustment may be required to reduce the high pH created by
the alkaline treatment chemicals.
Chemical precipitation as a mechanism for removing metals from
wastewater is a complex process of at least two steps -
precipitation of the unwanted metals and removal of the
precipitate. Some very small amount of metal will remain
dissolved in the wastewater after complete precipitation. The
amount of residual dissolved metal depends on the treatment
chemicals used and related factors. The effectiveness of this
method of removing any specific metal depends on the fraction of
the specific metal in the raw waste {and hence in the
precipitate) and the effectiveness of suspended solids removal.
In specific instances, a sacrificial ion such as iron or aluminum
may be added to aid in the removal of toxic metals by
coprecipitation process and reduce the fraction of a specific
metal in the precipitate.
Application. Chemical precipitation can be used to remove metal
ions such as aluminum, antimony, arsenic, beryllium, cadmium,
chromium, copper, iron, lead, manganese, mercury, nickel,
selenium, silver, and zinc. The process is also applicable to
any substance that can be transformed into an insoluble form such
as fluorides, phosphates, soaps, sulfides, and others. Because
it is simple and effective, chemical precipitation is extensively
used for industrial waste treatment.
The performance of chemical precipitation depends on several
variables. The more important factors affecting precipitation
effectiveness are:
1. Maintenance of an appropriate (usually alkaline) pH
throughout the precipitation reaction and subsequent
settling; irrespective of the solids removal technology
employed, proper control if pH is absolutely essential
for favorable performance of precipitation-
sedimentation technologies;
2. Addition of a sufficient excess of treatment ions to
drive the precipitation reaction to completion;
3. Addition of an adequate supply of sacrificial ions
(such as iron or aluminum) to ensure precipitation and
removal of specific target ions; and
315
-------
4. Effective removal of precipitated solids (see
appropriate solids removal technologies).
Sulfide gr ec i pi tat i on is sometimes used to precipitate metals
resul"t"ing in improved metals removals. Host metal gulf ides are
less soluble than hydroxides, and the precipitates are frequently
more dependably removed from water. Solubilities for selected
metal hydroxide, carbonate and sulfide precipitates are shown in
Table VI1-3. (Source: Lange's Handbook of Chemistry). Sulfide
precipitation is particularly effective ~Tn removing specific
metals such as silver and mercury.
Carbonate precipitation is sometimes used to precipitate metals,
especially where precipitated metals values are to be recovered.
The solubility of most metal carbonates is intermediate between
hydroxide and sulfide solubilities; in addition, carbonates form
easily filtered precipitates.
Carbonate ions appear to be particularly useful in precipitating
lead and antimony. Sodium carbonate has been observed being
added at treatment to improve lead precipitation and removal in
some industrial plants. The lead hydroxide and lead carbonate
solubility curves displayed in Figure VII-2 {"Heavy Metals
Removal," by Kenneth Lanouette, Chemical Engineering/Deskbook
Issue, October 17, 1977) explain this phenomenon.
C op r e c i p i tat ion With Iron. The presence of substantial
quantities of iron in metaT^earing wastewaters before treatment
has been shown to improve the removal of toxic metals. In some
cases this iron is an integral part of the industrial wastewater;
in other cases iron is deliberately added as a pretreatment or
first step of treatment. The iron functions to improve toxic
metal removal by three mechanisms: the iron coprecipitates with
toxic metals forming a stable precipitate which desolubilizes the
toxic metal; the iron improves the settleability of the
precipitate; and the large amount of iron reduces the fraction of
toxic metal in the precipitate. Coprecipitation with iron has
been practiced for many years incidentally when iron was a
substantial constituent of raw wastewater and intentionally when
iron salts were added as a coagulant aid. Aluminum or mixed
iron-aluminum salt also have been used. The addition of iron for
coprecipitation to aid in toxic metals removal is considered a
routine part of state-of-the-art lime and settle technology which
should be implemented as required to achieve optimal removal of
toxic metals.
Coprecipitation using large amounts of ferrous iron salts is
known as ferrite coprecipitation because magnetic iron oxide or
ferrite is formed. The addition of ferrous salts (sulfate) is
followed by alkali precipitation and air oxidation. The
resultant precipitate is easily removed by filtration and may be
removed magnetically.
316
-------
Advantages and Limitations. Chemical precipitation has proved to
beaneffectivetechnique for removing many pollutants from
industrial wastewater. It operates at ambient conditions and is
well suited to automatic control. The use of chemical
precipitation may be limited because of interference by chelating
agents/ because of possible chemical interference with mixed
wastewaters and treatment chemicals, or because of the
potentially hazardous situation involved with the storage and
handling of those chemicals. Metal molding and casting
wastewaters do not normally contain chelating agents or complex
pollutant matrix formations which would interfere with or limit
the use of chemical precipitation. Lime is usually added as a
slurry when used in hydroxide precipitation. The slurry must be
kept well mixed and the addition lines periodically checked to
prevent blocking of the lines, which may result from a buildup of
solids. Also, lime precipitation usually makes recovery of the
precipitated metals difficult, because of the heterogeneous
nature of most lime sludges.
The major advantage of the sulfide precipitation process is that
the extremely low solubility of most metal sulfides promotes very
high metal removal efficiencies. In addition, sulfide can
precipitate metals complexed with most complexing agents. The
process demands care, however, in maintaining the pH of the
solution at approximately 10 in order to restrict the generation
of toxic hydrogen sulfide gas. For this reason, ventilation of
the treatment tanks may be a necessary precaution in most
installations. The use of insoluble sulfides reduces the problem
of hydrogen sulfide evolution. As with hydroxide precipitation,
excess sulfide ion must be present to drive the precipitation
reaction to completion. Since the sulfide ion itself is toxic,
sulfide addition must be carefully controlled to maximize heavy
metals precipitation with a minimum of excess sulfide to avoid
the necessity of post treatment. At very high excess sulfide
levels and high pH, soluble mercury-sulfide compounds may also be
formed. Where excess sulfide is present, aeration of the
effluent stream can aid in oxidizing residual sulfide to the less
harmful sodium sulfate {N32SO4). The cost of sulfide
precipitants is high in comparison to hydroxide precipitants, and
disposal of metallic sulfide sludges may pose problems. An
essential element in effective sulfide precipitation is the
removal of precipitated solids from the wastewater and proper
disposal in an appropriate site. Sulfide precipitation will also
generate a higher volume of sludge than hydroxide precipitation,
resulting in higher disposal and dewatering costs. This is
especially true when ferrous sulfide is used as the precipitant.
Sulfide precipitation may be used as a polishing treatment after
hydroxide precipitation-sedimentation. This treatment
configuration may provide the better treatment effectiveness of
sulfide precipitation while minimizing the variability caused by
changes in raw waste and reducing the amount of sulfide
precipitant required.
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Operational Factors. Reliability: Alkaline chemical
precipitation is highly reliable, although proper monitoring and
control are required. Sulfide precipitation systems provide
similar reliability.
Maintainability: The major maintenance needs involve periodic
upkeep of monitoring equipment, automatic feeding equipment,
mixing equipment, and other hardware. Removal of accumulated
sludge is necessary for efficient operation of precipitation-
sedimentation systems.
Solid Waste Aspects: Solids which precipitate out are removed in
a subsequent treatment step. Ultimately, these solids require
proper disposal.
Demon strati on Status, Chemical precipitation of metal hydroxides
Tsaclassic waste treatment technology used by most industrial
waste treatment systems. Chemical precipitation of some metals,
in particular lead and antimony, in the carbonate form has been
found to be feasible and is commercially used to permit metals
recovery and water reuse. Full scale commercial sulfide
precipitation units are in operation at numerous industrial
wastewater installations. As noted earlier, sedimentation to
remove precipitates is discussed separately.
Fifty-three metal molding and casting plants in the metal molding
and casting data base operate chemical precipitation {lime or
caustic) treatment systems. The Agency has reviewed available
performance data for these treatment systems and has identified
nine plants that have well-operated chemical precipitation
treatment systems. The development of treated effluent
concentrations based on the data for these well-operated
treatment systems is described later in this section.
3. Emulsion Breaking
Emulsion breaking is the process of separating an emulsified oil
and water mixture. Emulsified oils are used as coolants,
lubricants, and antioxidants in many metal molding and casting
operations. Discussions of the two methods of emulsion breaking,
chemical and thermal, follow.
Chemical emulsion breaking can be accomplished as a batch process
or as a continuous process. In the batch process, the mixture of
emulsified oil and water is collected in large tanks equipped
with agitators and a skimmer or some method of decanting.
Decanting can be accomplished with a series of taps positioned at
various levels. Using the taps sequentially, the separated
material is drawn off of the surface of the tank contents. As an
alternate method, water can be drawn off near the bottom of the
tank until oil appears in the wastewater line. At this point,
the oil is diverted to storage tanks for reprocessing or hauling
by a licensed contractor. In the continuous process, a skimmer,
skimming trough, or similar surface material removal device can
be used to remove the material broken out of emulsion. The
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treated effluent would then be discharged from the separation
tank.
The chemical emulsion breaking process involves several steps.
First, the pH of the solution is lowered to an acidic state
(typically a pH of 3 to 4). The second step involves the
addition of an iron or aluminum salt (e.g., ferrous sulfate),
ferric chloride, or aluminum sulfate. These salts are used to
break the emulsion and free the oils from the water. In
conjunction with the addition of these salts, the mixture is
agitated to ensure complete contact of the wastewater/oil mixture
with the de-emulsifying agent. With the addition of the proper
amount of metallic salts and thorough agitation, emulsions o£ oil
at concentrations of 5,000 mg/1 or more can be reduced to
approximately 5 mg/1 remaining oil. In the third step of the
emulsion breaking process, sufficient time is allowed for the
oil/water mixture to separate.
Differences in specific gravity will permit the oil to rise to
the surface in approximately 2 to 8 hours. After separation, the
normal procedure involves skimming or decanting the oil from the
top of the tank. Heat, in the form of steam, can be added to
decrease the separation time. The fourth and final step involves
the addition of a chemical which desalts by precipitating metals
from the remaining wastewater solution. Calcium chloride or lime
are normally used as the desalting agents and will precipitate
out the metallic ions in the wastewater.
Thermal emulsion breaking can also be operated as a continuous or
batch process. In most cases, however, these systems are
operated intermittently, due to the batch dump nature of most
emulsified oil systems. The emulsified raw waste is collected in
a holding tank until sufficient volume has accumulated to warrant
operating the Thermal Emulsion Breaker (TEB). The TEB most
commonly used is an evaporation-distillation-decantation
apparatus which separates the spent emulsion into distilled
water, oils and other floating particles, and sludge. Initially,
the raw waste flows from the holding tank into the main
conveyorized chamber. Warm dry air is passed over a large
revolving drum which is partially submerged in the emulsion.
Water evaporates from the surface of the drum and is carried
upward through a filter and a condensing unit. The condensed
water is discharged and can be reused as process makeup, while
the air is reheated and returned to the evaporation stage. As
the concentration of water in the main conveyorized chamber
decreases, oil concentration increases and some gravity
separation occurs. The oils and other emulsified wastes which
separate flow over a weir into a decanting chamber. A rotating
drum skimmer picks up oil from the surface of this chamber and
discharges it for possible reprocessing or licensed contractor
removal. Meanwhile, oily water is drawn from the bottom of the
decanting chamber, reheated, and sent back into the main
conveyorized chamber. This aids in increasing the concentration
of oil in the main chamber and the amount of oil which floats to
the top. Solids which settle out in the main chamber are removed
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by a conveyor mechanism, called a flight scraper, which moves
slowly so as not to disturb the settling action.
Applj.catj.on. Emulsion breaking technology can be applied to the
treatment of emulsified solutions in the metal molding and
casting industry wherever it is necessary to separate oils, fats,
soaps, etc. from aqueous solutions.
Advantages and Limitations. The main advantage of the chemical
emulsion breaking process is the high percentage of oil removal
possible with this system (at least 99 percent in most cases).
For proper and economical application of this process, the oily
wastes {oil/water mixture) should be segregated from other
wastewaters either by storage in a holding tank prior to treat
ment or by direct inlet to the oily waste removal system from
major collection points. Further, if significant quantities of
free oils are present, it is advantageous to precede emulsion
breaking with gravity sedimentation. Chemical and energy costs
can be high, especially if heat is used to accelerate the
process.
Advantages of the TEB include an extremely high percentage of oil
removal (at least 99 percent in most cases), the separation of
floating oil from settleable sludge, and the production of good
quality water which is available for process reuse. In addition,
no chemical additives are required and the operation is fully
automatic, factors which reduce operating costs and maintenance
requirements. Disadvantages of this system are few: the cost of
heat to run the small boiler (about $80 a month for natural gas
for an 1,140 liters/day (300 gallon per day) unit), and the
necessary installation of a large storage tank. Some settling
may occur in the holding tank, resulting in a more concentrated
raw waste load during the first day or two of operation. TEB
models are currently available to handle loads of 150, 300, and
600 gallons per day,
Operational Factors. Reliability: Chemical emulsion breaking
can be highly reliable assuming adequate analysis in the
selection of chemicals and proper operator training to ensure
that the established procedures are followed.
Thermal emulsion breaking is also a very reliable process for the
treatment of emulsified wastes.
Maintainability: For chemical emulsion breaking, routine
maintenance is required on pumps, motors, and valves as well as
periodic cleaning of the treatment tank to remove any sediment
which may accumulate in the tank. The use of acid or acidic
conditions will require a lined or coated tank, and the lining or
coating should be checked periodically.
A TEB unit requires minimal routine maintenance of the TEB
components, and periodic disposal of sludge and oil.
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Solid Waste Aspects: Both methods of emulsion breaking generate
sludge oils which must receive proper disposal.
Demonstrat_ion St aj: iis. Emulsion breaking is a common treatment
technique ulfed by a number of plants, particularly to treat
aluminum and zinc die casting wastewater in the metal molding and
casting industry. It is a proven method of effectively treating
emulsified wastes.
4. Granular Bed Filtration
Filtration occurs in nature as the surface and ground waters are
cleansed by sand. Silica sand, anthracite coal, and garnet are
common filter media used in water treatment plants. These are
usually supported by gravel. The media may be used singly or in
combination. The multimedia filters may be arranged to maintain
relatively distinct layers by virtue of balancing the forces of
gravity, flow, and buoyancy on the individual particles. This is
accomplished by selecting appropriate filter flow rates (gpm/sq-
ft), media grain size, and density.
Granular bed filters may be classified in terms of filtration
rate, filter media, flow pattern, or method of pressurization.
Traditional rate classifications are slow sand, rapid sand, and
high rate mixed media. In the slow sand filter, flux or
hydraulic loading is relatively low, and removal of collected
solids to clean the filter is therefore relatively infrequent.
The filter is often cleaned by scraping off the inlet face (top)
of the sand bed. In the higher rate filters, cleaning is
frequent and is accomplished by a periodic backwash, opposite to
the direction of normal flow.
A filter may use a single medium such as sand or diatomaceous
earth, but dual and mixed (multiple) media filters allow higher
flow rates and efficiencies. The dual media filter usually
consists of a fine bed of sand under a coarser bed of anthracite
coal. The coarse coal removes most of the influent solids, while
the fine sand performs a polishing function. At the end of the
backwash, the fine sand settles to the bottom because it is
denser than the coal, and the filter is ready for normal
operation. The mixed media filter operates on the same
principle, with the finer, denser media at the bottom and the
coarser, less dense media at the top. The usual arrangement is
garnet at the bottom (outlet end) of the bed, sand in the middle,
and anthracite coal at the top. Some mixing of these layers
occurs and is, in fact, desirable.
The flow pattern is usually top-to-bottom, but other patterns are
sometimes used. Upflow filters are sometimes used, and in a
horizontal filter the flow is horizontal. In a biflow filter,
the influent enters both the top and the bottom and exits
laterally. The advantage of an upflow filter is that with an
upflow backwash, the ' particles of a single filter medium are
distributed and maintained in the desired coarse-to-fine {bottom-
to-top) arrangement. The disadvantage is that the bed tends to
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become fluidized, which ruins filtration efficiency. The biflow
design is an attempt to overcome this problem.
The classic granular bed filter operates by gravity flow;
however, pressure filters are fairly widely used. They permit
higher solids loadings before cleaning and are advantageous when
the filter effluent must be pressurized for further downstream
treatment. In addition, pressure filter systems are often less
costly for low to moderate flow rates.
Figure VII-3 depicts a high rate, dual media, gravity downflow
granular bed filter, with self-stored backwash. Both filtrate
and backwash are piped around the bed in an arrangement that
permits gravity upflow of the backwash, with the stored filtrate
serving as backwash. Addition of the indicated coagulant and
polyelectrolyte usually results in a substantial improvement in
filter performance.
Auxiliary filter cleaning is sometimes employed in the upper few
inches of filter beds. This is conventionally referred to as
surface wash and is accomplished by water jets just below the
surface of the expanded bed during the backwash cycle. These
jets enhance the scouring action in the bed by increasing the
agitation.
An important feature for successful filtration and backwashing is
the underdrain. This is the support structure for the bed. The
underdrain provides an area for collection of the filtered water
without clogging from either the filtered solids or the media
grains. In addition, the underdrain prevents loss of the media
with the water, and during the backwash cycle it provides even
flow distribution over the bed. Failure to dissipate the
velocity head during the filter or backwash cycle will result in
bed upset and the need for major repairs.
Several standard approaches are employed for filter underdrains,
The simplest one consists of a parallel porous pipe imbedded
under a layer of coarse gravel and attached via a manifold to a
header pipe for effluent removal. Other approaches to the
underdrain system are known as the Leopold and Wheeler filter
bottoms. Both of these incorporate false concrete bottoms with
specific porosity configurations to provide drainage and velocity
head dissipation.
Filter system operation may be manual or automatic. The filter
backwash cycle may be on a timed basis, a pressure drop basis
with a terminal value which triggers backwash, or a solids
carryover basis from turbidity monitoring of the outlet stream.
All of these schemes have been used successfully,
Application. Wastewater treatment plants often use granular bed
filters for polishing after clarification/ sedimentation, or
other similar operations. Granular bed filtration thus hag
potential application to nearly all industrial plants. Chemical
additives which enhance the upstream treatment equipment may or
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may not be compatible with or enhance the filtration process,
Normal operating flow rates for various types of filters are:
Slow Sand 2.04 - 5.30 1/sq m-hr
Rapid Sand 40.74 - 51.48 1/sq m-hr
High Rate Mixed Media 81.48 - 122.22 1/sq m-hr
Suspended solids are commonly removed from wastewater streams by
filtering through a deep 0.3-0,9 m (1-3 feet) granular filter
bed. The porous bed formed by the granular media can be designed
to remove practically all suspended particles. Even colloidal
suspensions (roughly 1 to 100 microns) are adsorbed on the
surface of the media grains as they pass in close proximity in
the narrow bed passages.
Advantages and Limitations. The principal advantages of granular
bed filtration are it's comparatively (to other filters) low
initial and operating costs, reduced land requirements over other
methods to achieve the same level of solids removal, and
elimination of chemical additions to the discharge stream.
However, the filter may require pretreatment if the solids level
is high (over 100 mg/1). Operator training mu be somewhat
extensive due to the controls and periodic backwashing involved,
and backwash must be stored and dewatered for economical
disposal.
Operational Factors. Reliability: The recent improvements in
filter technology have significantly improved filtration
reliability. Control systems, improved designs, and good
operating procedures have made filtration a highly reliable
method of water treatment.
Maintainability: Granular bed filters may be operated with
either manual or automatic backwash. In either case, they must
be periodically inspected for media attrition, partial plugging,
and leakage. Where backwashing is not used, collected solids
must be removed by shoveling, and filter media must be at least
partially replaced.
Solid Waste Aspects: Filter backwash is generally recycled
within the wastewater treatment system, so that the solids
ultimately appear in the clarifier sludge stream for subsequent
dewatering. Alternatively, the backwash stream may be dewatered
directly or, if there is no backwash, the collected solids may be
disposed of in a suitable landfill. in either of these
situations there is a solids disposal problem similar to that of
clarifiers.
Demons^raJbjLon S_tatu_s. Granular bed filters are used at 32 metal
molding and casting plants. They are also in common use in
municipal treatment plants. Their use in polishing industrial
clarifier effluent is increasing, and the technology is proven
and conventional.
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5- Oxidation by^ Potassium Permanganate
Permanganate oxidation is a chemical reaction by which wastewater
pollutants can be oxidized. When the reaction is carried to
completion, the by-products of the oxidation are not
environmentally harmful. A large number of pollutants can be
practically oxidized by permanganate, including cyanides,
hydrogen sulfide, and a variety of toxic organic pollutants
including phenol. In addition, the chemical oxygen demand (COD)
and many odors in wastewaters and sludges can be significantly
reduced by permanganate oxidation carried to its end point.
Potassium permanganate can be added to wastewater in either dry
or slurry form. As an example of the permanganate oxidation
process, the following chemical equation shows the oxidation of
phenol by potassium permanganate:
SCgHsfOH) + 28KMnO4 + 5H2 > 18CO2 + 28KOH + 28Mn02
Potassium permanganate cleaves the aromatic ring structure of
phenol to produce a straight chain aliphatic molecule. The
aliphatic is then further oxidized to CO2 and water.
One of the by-products of this oxidation is manganese dioxide
(Mn02)r which occurs as a relatively stable hydrous colloid
usually having a negative charge. These properties, in addition
to its large surface area, enable manganese dioxide to act as a
sorbent for metal cations, thus enhancing their removal from the
wastewater.
Application. Commercial use of permanganate oxidation has been
primarily for the control of phenol and waste odors. Several
municipal waste treatment facilities report that initial hydrogen
sulfide concentrations (causing serious odor problems) as high as
100 mg/1 have been reduced to zero through the application of
potassium permanganate. A variety of industries {including metal
finishers and agricultural chemical manufacturers) have used
permanganate oxidation to totally destroy phenol in their
wastewaters.
Tests have been performed on foundry wastewater to determine the
effectiveness and optimum operating conditions for oxidizing
phenol (4-AAP) and priority organic pollutants with permanganate.
These tests showed that optimum oxidation conditions occur at a
pH of 9 standard units and a dosage of 20 mg/1 of permanganate.
A retention time of 30 minutes was shown to be sufficient to
ensure that oxidation reactions of phenol and other organics had
gone to completion. These tests showed that permanganate
oxidation is an effective method for reducing phenol (4-AAP) and
priority organic pollutant concentrations in foundry wastewaters.
Advantages and Limitations. Permanganate oxidation has several
advantages as a wastewater treatment technique. Handling and
storage are facilitated by its non-toxic and non-corrosive
nature. Performance has been proved in a number of municipal and
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industrial applications. The tendency of the manganese dioxide
by-product to act as a coagulant aid is a distinct advantage over
other types of chemical treatment.
The cost of permanganate oxidation treatment can be limiting
where very large dosages are required to oxidize wastewater
pollutants. In addition, care must be taken in storage to
prevent exposure to intense heat, acids, or reducing agents?
exposure could create a fire hazard or cause explosions. Of
greatest concern is the environmental hazard which the use of
manganese chemicals in treatment could cause. Care must be taken
to remove the manganese from treated water in a settling or
clarification step before discharge,
Operational Factors. Reliability: Maintenance consists of
periodic sludge removal and cleaning of pump feed lines.
Frequency of maintenance is dependent on wastewater
characteristics.
Solid Waste Aspects: Sludge is generated by the process where
the manganese dioxide by-product tends to act as a coagulant aid.
The sludge from permanganate oxidation can be collected and
handled by standard sludge treatment and processing equipment.
Demonstration Status. The oxidation of wastewater pollutants by
potassium permanganate is a proven treatment process in several
types of industries. It has been shown effective in treating a
wide variety of pollutants in both municipal and industrial
wastes, including metal molding and casting wastewaters.
Pilot studies of potassium permanganate oxidation have been
completed for treatment of metal molding and casting wastewaters.
An industrial study of wastewaters from ferrous foundry (plant
14069) reduced phenol from 0.123 mg/1 in raw wastewaters to <0.01
mg/1 in treated effluent using a dosage rate of 10 mg/1 {80:1,
permanganate:phenol} of potassium permanganate. h second pilot
treatability study, conducted by EPA, reduced phenol from 1.1
mg/1 in raw wastewaters to 0.022 mg/1 in treated effluent using a
potassium permanganate dosage of 20 mg/1. Full-scale potassium
permanganate oxidation was used by plant 10837 to pretreat a
phenol-bearing wastewater stream prior to an emulsion breaking
and clarification treatment facility. However, use of this
system was discontinued because an existing biological treatment
system used to treat domestic wastes at this plant effectively
reduced total phenols. Reduced treatment efficiency at low raw
wastewater phenol concentrations and heavy sludges were also
cited as reasons for discontinuing operation, although no data or
documentation were supplied to define these circumstances.
In another industrial application, potassium permanganate is used
to treat a waste stream bearing 1 to 4 mg/1 phenol. Potassium
permanganate is added prior to a chemical precipitation, solids
removal treatment system. Potassium permanganate dosages of from
5 to 20 mg/1 produce a phenol-free effluent. Manganese dioxide,
produced as a result of the oxidation reaction, is coagulated and
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removed in the chemical precipitation, solids removal treatment
system.
6. Pressure Fj.jj_ratj.gn
Pressure filtration works by pumping the liquid through a filter
material which is impenetrable to the solid phase. The positive
pressure exerted by the feed pumps or other mechanical means
provides the pressure differential which is the principal driving
force. Figure VII-4 represents the operation of one type of
pressure filter.
A typical pressure filtration unit consists of a number of plates
or trays which are held rigidly in a frame to ensure alignment
and which are pressed together between a fixed end and a
traveling end. On the surface of each plate, a filter made of
cloth or synthetic fiber is mounted. The feed stream is pumped
into the unit and passes through holes in the trays along the
length of the press until the cavities or chambers between the
trays are completely filled. The solids are then entrapped, and
a cake begins to form on the surface of the filter material. The
water passes through the fibers, and the solids are retained.
At the bottom of the trays are drainage ports. The filtrate is
collected and discharged to a common drain. As the filter medium
becomes coated with sludge, the flow of filtrate through the
filter drops sharply, indicating that the capacity of the filter
has been exhausted. The unit must then be cleaned of the sludge.
After the cleaning or replacement of the filter media, the unit
is again ready for operation.
In a typical pressure filter, chemically preconditioned sludge
detained in the unit for one to three hours under pressures
varying from 5 to 13 atmospheres exhibited final solids content
between 25 and 50 percent.
Application. Pressure filtration is used in metal molding and
casting plants for sludge dewatering and also for direct removal
of precipitated and other suspended solids from wastewater,
Because dewatering is such a common operation in treatment
systems, pressure filtration is a technique which can be found in
many industries concerned with removing solids from their waste
stream.
Advantages and Limitations. The pressures which may be applied
to a sludge for removal of water by filter presses that are
currently available range from 5 to 13 atmospheres. As a result,
pressure filtration may reduce the amount of chemical
pretreatment required for sludge dewatering. Sludge retained in
the form of the filter cake has a higher percentage of solids
than that from centrifuge or vacuum filter. Thus, it can be
easily accommodated by materials handling systems.
As a primary solids removal technique, pressure filtration
requires less space than clarification and is well suited to
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streams with high solids loadings. The sludge produced may be
disposed without further dewatering, but the amount of sludge is
increased by the use of filter precoat materials (usually
diatomaceous earth). Also, cloth pressure filters often do not
achieve as high a degree of effluent clarification as clarifiers
or granular media filters.
Two disadvantages associated with pressure filtration in the past
have been the short life of the filter cloths and lack of
automation. New synthetic fibers have largely offset the first
of these problems. Also, units with automatic feeding and
pressing cycles are now available.
For larger operations, the relatively high space requirements, as
compared to those of a centrifuge, could be prohibitive in some
situations.
Operational Fac tor s. Reliability; With proper pretreatment,
design, and control, pressure filtration is a highly dependable
system.
Maintainability: Maintenance consists of periodic cleaning or
replacement of the filter media, drainage grids, drainage piping,
filter pans, and other parts of the system. If the removal of
the sludge cake is not automated, additional time is required for
this operation.
Solid Waste Aspects: Because it is generally drier than other
types of sludges, the filter sludge cake can be handled with
relative ease. The accumulated sludge may be disposed by any of
the accepted procedures depending on its chemical composition,
The levels of toxic metals present in sludge from treating metal
molding and casting wastewater necessitate proper disposal.
Demonstration Status, Pressure filtration is a commonly used
technology in a great many commercial applications. Pressure
filtration is employed by 28 plants in the metal molding and
casting data base.
7. Settling
Settling is a process which removes solid particles from a liquid
matrix by gravitational force. This is done by reducing the
velocity of the feed stream in a large volume tank or lagoon so
that gravitational settling can occur. Figure VII-5 shows two
typical settling devices.
Settling is often preceded by chemical precipitation which
converts dissolved pollutants to solid form and by coagulation
which enhances settling by coagulating suspended precipitates
into larger, faster settling particles,
If no chemical pretreatment is used, the wastewater is fed into a
tank or lagoon where it loses velocity and the suspended solids
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are allowed to settle out. Long retention times are generally
required. Accumulated sludge can be collected either
periodically or continuously and either manually or mechanically.
Simple settling, however, may require excessively large
catchments, and long retention times (days as compared with
hours) to achieve high particulate removal efficiencies. Because
of this, addition of settling aids such as alum or polymeric
flocculants is often economically attractive.
In practice, chemical precipitation often precedes settling, and
inorganic coagulants or polyelectrolytic flocculants are usually
added as well. Common coagulants include sodium sulfate, sodium
aluminate, ferrous or ferric sulfate, and ferric chloride.
Organic polyelectrolytes vary in structure, but all usually form
larger floe particles than coagulants used alone.
Following this pretreatment, the wastewater can be fed into a
holding tank or lagoon for settling, but is more often piped into
a clarifier for the same purpose, A clarifier reduces space
requirements, reduces retention time, and increases solids
removal efficiency. Conventional clarifiers generally consist of
a circular or rectangular tank with a mechanical sludge
collecting device or with a sloping funnel-shaped bottom designed
for sludge collection. In advanced settling devices, inclined
plates, slanted tubes, or a lamellar network may be included
within the clarifier tank in order to increase the effective
settling area, increasing capacity. A fraction of the sludge
stream is often recirculated to the inlet, promoting formation of
a denser sludge.
Settling is based on the ability of gravity to cause small
particles to fall or settle {Stokes1 Law) through the fluid they
are suspended in. Presuming that the factors affecting chemical
precipitation are controlled to achieve a readily settleable
precipitate, the principal factors controlling settling are the
particle characteristics and the upflow rate of the suspending
fluid. When the effective settling area is great enough to allow
settling, any increase in the effective settling area will
produce no increase in solids removal.
Therefore, if a plant has installed equipment that provides the
appropriate overflow rate, the precipitated metals in the
effluent can be effectively removed. The number of settling
devices operated in series or in parallel by a facility is not
important with regard to suspended solids removal; rather it is
important that the settling devices provide sufficient effective
settling area.
Another important facet of sedimentation theory is that
diminishing removal of suspended solids is achieved for a unit
increase in the effective settling area. Generally, it has been
found that suspended solids removal performance varies with the
effective upflow rate. Qualitatively the performance increases
asymmetrically to a maximum level beyond which a decrease in
upflow rate provides incrementally insignificant increases in
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removal. This maximum level is dictated by particle size
distribution, density characteristic of the particles and the
water matrix, chemicals used for precipitation and pH at which
precipitation occurs.
Application. Settling or clarification is used extensively in
the metal molding and casting category to remove particulate
matter and/or precipitated metals. Settling can be used to
remove most suspended solids in a particular waste stream? thus
it is used extensively by many different industrial waste
treatment facilities. Because most metal ion pollutants are
readily converted to solid metal hydroxide precipitates, settling
is of particular use in those industries associated with metal
production, metal finishing, metal working, and any other
industry with high concentrations of metal ions in their
wastewaters. In addition to priority pollutant metals, suitably
precipitated materials effectively removed by settling include
aluminum, iron, manganese, molybdenum, fluoride, phosphate, and
many others.
A properly operating settling system can efficiently remove
suspended solids, precipitated metal hydroxides, and other
impurities from wastewater. The performance of the process
depends on a variety of factors, including the density and
particle size of the solids, the effective charge on the
suspended particles, and the types of chemicals used in
pretreatment. The site of flocculant or coagulant addition also
may significantly influence the effectiveness of clarification.
If the flocculant is subjected to too much mixing before entering
the clarifier, the complexes may be sheared and the settling
effectiveness diminished. At the same time, the flocculant must
have sufficient mixing and reaction time in order for effective
set-up and settling to occur. Plant personnel have observed that
the line or trough leading into the clarifier is often the most
efficient site for flocculant addition. The performance of
simple settling is a function of the retention time, particle
size and density, and the surface area of the basin.
Advantages and Limitations. The major advantage of simple
settling is its simplicity as demonstrated by the gravitational
settling of solid particulate waste in a holding tank or lagoon.
The major problem with simple settling is the long retention time
necessary to achieve complete settling, especially if the
specific gravity of the suspended matter is close to that of
water. Some materials, particularly dissolved metals, cannot be
practically removed by simple settling alone.
Settling performed in a clarifier is effective in removing slow-
settling suspended matter in a shorter time and in less space
than a simple settling system. Also, effluent quality is often
better from a clarifier. The cost of installing and maintaining
a clarifier, however, is substantially greater than the costs
associated with simple settling.
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Inclined plate, slant tube, and lamella settlers have even higher
removal efficiencies than conventional clarifiers/ and greater
capacities per unit area are possible. Installed costs for these
advanced clarification systems are claimed to be one half the
cost of conventional systems of similar capacity.
Opjer^j-ona^l Factors. Reliability: Settling can be a highly
reliable technology for removing suspended solids* Sufficient
retention time and regular sludge removal are important factors
affecting the reliability of all settling systems. Proper
control of pH adjustment, chemical precipitation, and coagulant
or flocculant addition are additional factors affecting settling
efficiencies in systems (frequently clarifiers} where these
methods are used.
Those advanced settlers using slanted tubes, inclined plates, or
a lamellar network may require prescreening of the waste in order
to eliminate any fibrous materials which could potentially clog
the system. Some installations are especially vulnerable to
shock loadings, as from storm water runofff but proper system
design will prevent this.
Maintainability: When clarifiers or other advanced settling
devices are used, the associated system utilized for chemical
pretreatment and sludge dragout must be maintained on a regular
basis. Routine maintenance of mechanical parts is also
necessary. Lagoons require little maintenance other than
periodic sludge removal.
Demonstration Status. Settling represents the typical method of
solidsremoval and is employed extensively in industrial waste
treatment. Sedimentation or clarification are used extensively
in the metal molding and casting category; 179 plants in the
metal molding and casting data base report the use of settling
technology.
Settling is used both as part of end-of-pipe treatment and within
process water recycle systems.
8. Skimming
Pollutants with a specific gravity less than water will often
float unassisted to the surface of the wastewater. Skimming
removes these floating wastes. Skimming normally takes place in
a tank designed to allow the floating debris to rise and remain
on the surface, while the liquid flows to an outlet located below
the floating layer. Skimming devices are therefore suited to the
removal of non-emulsified oils from raw waste streams. Common
skimming mechanisms include the rotating drum type, which picks
up oil from the surface of the water as it rotates. A doctor
blade scrapes oil from the drum and collects it in a trough for
disposal or reuse. The water portion is allowed to flow under
the rotating drum. Occasionally, an underflow baffle is
installed after the drum; this has the advantage of retaining any
floating oil which escapes the drum skimmer. The belt type
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skimmer is pulled vertically through the water, collecting oil
which is scraped off from the surface and collected in a drum.
Gravity separators, such as the API type, utilize overflow and
underflow baffles to skim a floating oil layer from the surface
of the wastewater. An overflow-underflow baffle allows a small
amount of wastewater {the oil portion) to flow over into a trough
for disposition or reuse while the majority of the water flows
underneath the baffle. This is followed by an overflow baffle,
which is set at a height relative to the first baffle such that
only the oil bearing portion will flow over the first baffle
during normal plant operation. A diffusion device, such as a
vertical slot baffle, aids in creating a uniform flow through the
system and in increasing oil removal efficiency.
Appj.ication. Oil skimming is used at metal molding and casting
plants to remove free oil from wastewater. Free oil originates
from machinery and die lubricants, mold release agents, hydraulic
system leaks, and oily material collected by melting furnace and
dust scrubbers. Skimming is applicable to any waste stream
containing pollutants which float to the surface. It is commonly
used to remove free oil, grease, and soaps. Skimming is often
used in conjunction with emulsion breaking, air flotation or
clarification in order to increase its effectiveness.
The removal efficiency of a skimmer is partly a function of the
retention time of the water in the tank. Larger, more buoyant
particles require less retention time than smaller particles.
Thus, the efficiency also depends on the composition of the waste
stream. The retention time required to allow phase separation
and subsequent skimming varies from 1 to 15 minutes, depending on
the wastewater characteristics.
API or other gravity-type separators tend to be more suitable for
use where the amount of surface oil flowing through the system is
consistently significant. Figure VII-6 depicts a typical
gravity-type separator. Drum and belt type skimmers are
applicable to waste streams which evidence smaller amounts of
floating oil and where surges of floating oil are not a problem.
Using an API separator system in conjunction with a drum type
skimmer is a very effective method of removing floating
contaminants from non-emulsified oily waste streams.
Skimming which removes oil and grease will also remove organic
priority pollutants. High molecular weight organics in
particular are much more soluble in organic solvents than in
water. Thus they are much more concentrated in the oil phase
that is skimmed than in the wastewater. The ratio of
solubilities of a compound in oil and water phases is called the
partition coefficient. The logarithm of the partition
coefficients for selected polynuclear aromatic hydrocarbon (PAH)
and other toxic organic compounds in octanol and water are
presented later in this section under the discussion of treatment
option development.
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Advantages and Limitations. Skimming as a pretreatment Is
effective in removing naturally floating waste material. It also
improves the performance of subsequent downstream treatments.
Many pollutants, particularly dispersed or emulsified oil, will
not float "naturally" but require additional treatments.
Therefore, skimming alone may not remove all the pollutants
capable of being removed by air flotation or other more
sophisticated technologies.
Operational Factors. Reliability: Because of its simplicity,
skimming is a very reliable technique.
Maintainability: The skimming mechanism requires periodic
lubrication, adjustment, and replacement of worn parts.
Solid Waste Aspects: The collected layer of debris must be
disposed of by contractor removal, landfill, or incineration.
Because relatively large quantities of water are present in the
collected wastes, incineration is not always a viable disposal
method.
Demonstration Status. Skimming is a common operation utilized
extensively by Industrial waste treatment systems. Oil skimming
is used at 61 plants in the metal molding and casting data base.
9. Vacuum Filtration
In wastewater treatment plants, sludge dewatering by vacuum
filtration generally uses cylindrical drum filters. These drums
have a filter medium which may be cloth made of natural or
synthetic fibers or a wire-mesh fabric. The drum is suspended
above and dips into a vat of sludge. As the drum rotates slowly,
part of its circumference is subject to an internal vacuum that
draws sludge to the filter medium. Water is drawn through the
porous filter cake to a discharge port, and the dewatered sludge,
loosened by compressed air, is scraped from the filter mesh.
Because the dewatering of sludge on vacuum filters is relatively
expensive per kilogram of water removed, the liquid sludge is
frequently thickened prior to processing. A vacuum filter is
shown in Figure VII-7.
The function of vacuum filtration is to reduce the water content
of sludge, so that the solids content increases from about 5
percent to about 30 percent,
Application. Vacuum filters are frequently used both in
municipal treatment plants and in a wide variety of industries
including the metal molding and casting industry. They are most
commonly used in larger facilities, which may have a thickener to
double the solids content of clarifier sludge before vacuum
filtering.
Advantages and Limitations. Although the initial cost and area
requirement of the vacuum filtration system are higher than those
of a centrifuge, the operating cost is lower, and no special
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provisions for sound and vibration protection need be made. The
dewatered sludge from this process is in the form of a moist cake
and can be conveniently handled.
Operational Factors. Reliability: Vacuum filter systems have
proven reliable at many industrial and municipal treatment
facilities. At present, the largest municipal installation is at
the West Southwest wastewater treatment plant of Chicago,
Illinois, where 96 large filters were installed in 1925,
functioned approximately 25 years, and then were replaced with
larger units. Original vacuum filters at Minneapolis-St. Paul,
Minnesota, now have over 28 years of continuous service, and
Chicago has some units with similar or greater service life.
Maintainability: Maintenance consists of the cleaning or
replacement of the filter media, drainage grids, drainage piping,
filter pans, and other parts of the equipment. Experience in a
number of vacuum filter plants indicates that maintenance
consumes approximately 5 to 15 percent of the total time. If
carbonate buildup or other problems are unusually severe,
maintenance time may be as high as 20 percent. For this reason,
it is desirable to maintain one or more spare units.
If intermittent operation is used, the filter equipment should be
drained and washed each time it is taken out of service. An
allowance for this wash time must be made in filtering schedules.
Solid Waste Aspects: Vacuum filters generate a solid cake which
is usually trucked directly to landfill. All of the metals
extracted from the plant wastewater are concentrated in the
filter cake as hydroxides, oxides, sulfides, or other salts.
Demonstration Status. Vacuum filtration has been widely used for
many years. It is a fully proven, conventional technology for
sludge dewatering. The use of vacuum filtration is reported by
22 plants in the metal molding and casting data base.
MINOR TECHNOLOGIES
Several other end-of-pipe treatment technologies were considered
for possible application in this category. These include:
10. Centrifugation,
11. Coalescing,
12. Flotation,
13, Gravity sludge thickening,
14. Sludge bed drying, and
15. Ultrafiltration.
These technologies are presented here,
10 . Centrifugation
Centrifugation is the application of centrifugal force to
separate solids and liquids in a liquid-solid mixture or to
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effect concentration of the solids. The application of
centrifugal force is effective because of the density
differential normally found between the insoluble solids and the
liquid in which they are contained. As a waste treatment
procedure, centrifugation is applied to dewatering of sludges.
One type of centrifuge is shown in Figure VII-8.
There are three common types of centrifuges; disc, basket, and
conveyor. All three operate by removing solids under the
influence of centrifugal force. The fundamental difference among
the three types is the method by which solids are collected in
and discharged from the bowl.
In the disc centrifuge, the sludge feed is distributed between
narrow channels that are present as spaces between stacked
conical discs. Suspended particles are collected and discharged
continuously through small orifices in the bowl wall. The
clarified effluent is discharged through an overflow weir.
A second type of centrifuge which is useful in dewatering sludges
is the basket centrifuge. In this type of centrifuge, sludge
feed is introduced at the bottom of the basket, and solids
collect at the bowl wall while clarified effluent overflows the
lip ring at the top. Since the basket centrifuge does not have
provision for continuous discharge of collected cake, operation
requires interruption of the feed for cake discharge for a minute
or two in a 10- to 30-minute overall cycle.
The third type of centrifuge commonly used in sludge dewatering
is the conveyor type. Sludge is fed through a stationary feed
pipe into a rotating bowl in which the solids are settled out
against the bowl wall by centrifugal force. From the bowl wall,
the solids are moved by a screw to the end of the machine, at
which point they are discharged. The liquid effluent is
discharged through ports after passing the length of the bowl
under centrifugal force.
The performance of sludge dewatering by centrifugation depends on
the feed rate, the rotational velocity of the drum, and the
sludge composition and concentration. Assuming proper design and
operation, the solids content of the sludge can be increased to
20 to 35 percent.
App^ica^ticm.. Virtually all industrial waste treatment systems
producing sludge can use centrifuqat^on to dewater it.
Centrifugation is currently being used by a wide range of
industrial concerns.
Advantages and limitations. Slucgp oewaterinq >'?f.'^ r L?u-jei.-. have
minimal space "requirements and show a high degree of effluent
clarification. The operation is simple, clears and relatively
inexpensive. The area required for n cenrrifuge system
installation is less than that required for a filter system or
sludge drying bed of equal capacity, and : h«-.- initial cost is
lower.
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Centrifuges have a high power coat that partially offsets the low
initial cost. Special consideration must also be given to
providing sturdy foundations and soundproofing because of the
vibration and noise that result from centrifuge operation.
Adequate electrical power must also be provided since large
motors are required. The major difficulty encountered in the
operation of centrifuges has been the disposal of the concentrate
which is relatively high in suspended, nonsettling solids.
ggeratignal Factors. Reliability: Centrifugation is highly
reliable with proper control of factors such as sludge feed,
consistency, and temperature. Pretreatment such as grit removal
and coagulant addition may be necessary, depending on the
composition of the sludge and on the type of centrifuge employed*
Maintainability: Maintenance consists of periodic lubrication,
cleaning, and inspection. The frequency and degree of inspection
required varies depending on the type of sludge solids being
dewatered and the maintenance service conditions. If the sludge
is abrasive, it is recommended that the first inspection of the
rotating assembly be made after approximately 1,000 hours of
operation. If the sludge is not abrasive or corrosive, then the
initial inspection might be delayed. Centrifuges not equipped
with a continuous sludge discharge system require periodic
shutdowns for manual sludge cake removal.
Solid Waste Aspects: Sludge dewatered in the Centrifugation
process may be disposed of by landfill. The clarified effluent
(centrate), if high in dissolved or suspended solids, may require
further treatment prior to discharge.
Demonstration Status. Centrifugation is currently used in a
great many commercial applications to dewater sludge. Work is
underway to improve the efficiency, increase the capacity, and
lower the costs associated with Centrifugation.
11. Coalescing
The basic principle of coalescence involves the preferential
wetting of a coalescing medium by oil droplets which 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 wettability for oil and
large surface area. Monofilament line is sometimes used as a
coalescing medium.
Coalescing stages may be integrated with a wide variety of
gravity oil separation devices, and some systems may incorporate
several coalescing stages. In general, a preliminary oil
skimming step is desirable to avoid overloading the coalescer.
One commercially marketed system for oily waste treatment
combines coalescing with inclined plate separation and
filtration. In this system, the oily wastes flow into an
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inclined plate settler. This unit consists of a stack of
inclined baffle plates in a cylindrical container with an oil
collection chamber at the top. The oil droplets rise and impinge
upon the undersides of the plates. They then migrate upward to a
guide rib which directs the oil to the oil collection chamber,
from which oil is discharged for reuse or disposal.
The oily water continues on through another cylinder containing
replaceable filter cartridges, which remove suspended particles
from the waste. From there the wastewater enters a final
cylinder in which the coalescing material is housed. As the oily
water passes through the many small, irregular, continuous
passages in the coalescing material, the oil droplets coalesce
and rise to an oil collection chamber.
Appl i ca tjjpn . Coalescing is used to treat oily wastes which do
not separate readily in simple gravity systems. The three-stage
system described above has achieved effluent concentrations of 10
to 15 mg/1 oil and grease from raw waste concentrations of 1,000
mg/1 or more.
Advantages and Limi tations . Coalescing allows removal of oil
droplets too finely dispersed for conventional gravity
separation-skimming technology. It also can significantly reduce
the residence times (and therefore separator volumes) required to
achieve separation of oil from some wastes. Because of its
simplicity, coalescing provides generally high reliability and
low capital and operating costs. Coalescing is not generally
effective in removing soluble or chemically stabilized emulsified
oils. To avoid plugging, coalescers must be protected by
pretreatment from very high concentrations of free oil and grease
and suspended solids. Frequent replacement of pref liters may be
necessary when raw waste oil concentrations are high.
Ope r a tji onaj. Factors. Reliability: Coalescing is inherently
highly reliable since there are no moving parts, and the
coalescing substrate (monof i lament , etc.) is inert in the process
and therefore not subject to frequent regeneration or replacement
requirements. Large loads or inadequate pretreatment, however,
may result in plugging or bypass of coalescing stages.
Maintainability: Maintenance requirements are generally limited
to replacement of the coalescing medium on an infrequent basis,
Solid Waste Aspects: No appreciable solid waste is generated by
this process.
Demonstration Status. Coalescing has been fully demonstrated in
industries generating oily wastewater, although no metal molding
and casting plants specifically reported its use.
12.
Flotation is the process of causing particles such as metal
hydroxides or oil to float to the surface of a tank where they
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can be concentrated and removed. This is accomplished by
releasing gas bubbles which attach to the solid particles,
increasing their buoyancy and causing them to float. In
principle, this process is the opposite of sedimentation. Figure
VII-9 shows one type of flotation system.
Flotation is used primarily in the treatment of wastewater
streams that carry heavy loads of finely divided suspended solids
or oil. Solids having a specific gravity only slightly greater
than 1.0, which would require abnormally long sedimentation
times, may be removed in much less time by flotation. Dissolved
air flotation is of greatest interest in removing oil from water
and is less effective in removing heavier precipitates.
This process may be performed in several ways: foam, dispersed
air, dissolved air, gravity, and vacuum flotation are the most
commonly used techniques. Chemical additives are often used to
enhance the performance of the flotation process.
The principal difference among types of flotation is the method
of generating the minute gas bubbles (usually air) in a
suspension of water and small particles. Chemicals may be used
to improve the efficiency with any of the basic methods.
Descriptions of the different flotation techniques and the method
of bubble generation for each process follow.
Froth Flotation - Froth flotation is based on differences in the
physiochemical properties in various particles. Wetability and
surface properties affect the particles' ability to attach
themselves to gas bubbles in an aqueous medium. In froth
flotation, air is blown through the solution containing flotation
reagents. The particles with water repellant surfaces stick to
air bubbles as they rise and are brought to the surface. A
mineralized froth layer, with mineral particles attached to air
bubbles, is formed. Particles of other minerals which are
readily wetted by water do not stick to air bubbles and remain in
suspension.
Dispersed Air Flotation - In dispersed air flotation, gas bubbles
are generated by introducing the air by means of mechanical
agitation with impellers or by forcing air through porous media.
Dispersed air flotation is used mainly in the metallurgical
industry.
Dissolved Air Flotation - In dissolved air flotation, bubbles are
produced by releasing air from a supersaturated solution under
relatively high pressure. There are two types of contact between
the gas bubbles and particles. The first type is predominant in
the flotation of flocculated materials and involves the
entrapment of rising gas bubbles in the flocculated particles as
they increase in size. The bond between the bubble and particle
is one of physical capture only. The second type of contact is
one of adhesion. Adhesion results from the intermolecular
attraction exerted at the interface between the solid particle
and gaseous bubble.
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Vacuum Flotation - This process consists of saturating the
wastewater with air either directly in an aeration tank, or by
permitting air to enter on the suction of a wastewater pump. A
partial vacuum is applied, which causes the dissolved air to come
out of solution as minute bubbles. The bubbles attach to solid
particles and rise to the surface to form a scum blanket, which
is normally removed by a skimming mechanism. Grit and other
heavy solids that settle to the bottom are generally raked to a
central sludge pump for removal. A typical vacuum flotation unit
consists of a covered cylindrical tank in which a partial vacuum
is maintained. The tank is equipped with scum and sludge removal
mechanisms. The floating material is continuously swept to the
tank periphery, automatically discharged into a scum trough, and
removed from the unit by a pump also under partial vacuum.
Auxiliary equipment includes an aeration tank for saturating the
wastewater with air, a tank with a short retention time for
removal of large bubbles, vacuum pumps, and sludge pumps.
Appj.icatJ.on. The primary variables for flotation design are
pressure, feed solids concentration, and retention period. The
suspended solids in the effluent decrease, and the concentration
of solids in the float increases with increasing retention
period. When the flotation process is used primarily for
clarification, a retention period of 20 to 30 minutes usually is
adequate for separation and concentration,
Advantages and Limitations. Some advantages of the flotation
process are the high levels of solids separation achieved in many
applications, the relatively low energy requirements, and the
adaptability to meet the treatment requirements of different
waste types. Limitations of flotation are that it often requires
addition of chemicals to enhance process performance and that it
generates large quantities of solid waste.
Operational Factors. Reliability: Flotation systems normally
are very reliable with proper maintenance of the sludge collector
mechanism and the motors and pumps used for aeration.
Maintainability: Routine maintenance is required on the pumps
and motors. The sludge collector mechanism is subject to
possible corrosion or breakage and may require periodic
replacement.
Solid Waste Aspects: Chemicals are commonly used to aid the
flotation process by creating a surface or a structure that can
easily adsorb or entrap air bubbles. Inorganic chemicals, such
as the aluminum and ferric salts, and activated silica, can bind
the particulate matter together and create a structure that can
entrap air bubbles. Various organic chemicals can change the
nature of either the air-liquid interface or the solid-liquid
interface, or both. These compounds usually collect on the
interface to bring about the desired changes. The added
chemicals plus the particles in solution combine to form a large
volume of sludge which must be further treated or properly
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disposed.
Demons t ra t ion Status. Flotation is a fully developed process and
Is readily available for the treatment of a wide variety of
industrial waste streams.
13> G^avrty Sludge^ Thickening
In the gravity thickening process, dilute sludge is fed from a
primary settling tank or clarifier to a thickening tank where
rakes stir the sludge gently to increase the sludge density and
to push it to a central collection well. The supernatant is
returned to the primary settling tank. The thickened sludge that
collects on the bottom of the tank is pumped to dewatering
equipment or hauled away. Figure VII-10 shows the construction
of a gravity thickener.
Apjjlj^ca tion . Thickeners are generally used in facilities where
the sludge is to be further dewatered by a compact mechanical
device such as a vacuum filter or centrifuge. Doubling the
solids content in the thickener substantially reduces capital and
operating cost of the subsequent dewatering device and also
reduces cost for hauling. The process is potentially applicable
to almost any industrial plant.
Organic sludges from sedimentation units of one to two percent
solids concentration can usually be gravity thickened to 6 to 10
percent; chemical sludges can be thickened to 4 to 6 percent.
Adyanja^es and Limitations. The principal advantage of a gravity
sludge thickening process is that it facilitates further sludge
dewatering. Other advantages are high reliability and minimum
maintenance requirements.
Limitations of the sludge thickening process are its sensitivity
to the flow rate through the thickener and the sludge removal
rate. These rates must be low enough not to disturb the
thickened sludge.
Operational Factors. Reliability: Reliability is high with
proper design and operation. A gravity thickener is designed on
the basis of square feet per pound of solids per day, in which
the required surface area is related to the solids entering and
leaving the unit. Thickener area requirements are also expressed
in terms of mass loading, grams of solids per square meter per
day (Ibs/sq ft/day).
Maintainability: Twice a year, a thickener must be shut down for
lubrication of the drive mechanisms. Occasionally, water must be
pumped back through the system in order to clear sludge pipes.
Solid Waste Aspects: Thickened sludge from a gravity thickening
process will usually require further dewatering prior to
disposal, incineration, or drying. The clear effluent may be
recirculated in part, or ih may be subjected to further treatment
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prior to discharge.
Demonstration Status. Gravity sludge thickeners are used
through-out this industry to reduce water content to a level
where the sludge may be efficiently handled. Further dewatering
is usually practiced to minimize costs of hauling the sludge to
approved landfill areas.
14. Sludge Bed Drying
As a waste treatment procedure, sludge bed drying is employed to
reduce the water content of a variety of sludges to the point
where they are amenable to mechanical collection and removal to
landfill. These beds usually consist of 15 to 45 cm (6 to 18
in,) of sand over a 30 cm (12 in.) deep gravel drain system made
up of 3 to 6 mm (1/8 to 1/4 in.) graded gravel overlying drain
tiles. Figure VII-11 shows the construction of a drying bed.
Drying beds are usually divided into sectional areas
approximately 7*5 meters (25 ft) wide x 30 to 60 meters (100 to
200 ft) long. The partitions may be earth embankments, but more
often are made of planks and supporting grooved posts.
To apply liquid sludge to the sand bed, a closed conduit or a
pressure pipeline with valved outlets at each sand bed section is
often employed. Another method of application is by means of an
open channel with appropriately placed side openings which are
controlled by slide gates. With either type of delivery system,
a concrete splash slab should be provided to receive the falling
sludge and prevent erosion of the sand surface.
Where it is necessary to dewater sludge continuously throughout
the year regardless of the weather, sludge beds may be covered
with a fiberglass reinforced plastic or other roof. Covered
drying beds permit a greater volume of sludge drying per year in
most climates because of the protection afforded from rain or
snow and because of more efficient control of temperature.
Depending on the climater a combination of open and enclosed beds
will provide maximum utilization of the sludge bed drying
facilities.
Application, Sludge drying beds are a means of dewatering sludge
from clarifiers and thickeners. They are widely used both in
municipal and industrial treatment facilities.
Dewatering of sludge on sand beds occurs by two mechanisms:
filtration of water through the bed and evaporation of water as a
result of radiation and convection. Filtration is generally
complete in one to two days and may result in solids
concentrations as high as 15 to 20 percent. The rate of
filtration depends on the drainability of the sludge.
The rate of air drying of sludge is related to temperature,
relative humidity, and air velocity. Evaporation will proceed at
a constant rate to a critical moisture content, then at a falling
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rate to an equilibrium moisture content. The average evaporation
rate for a sludge is about 75 percent of that from a free water
surface.
Advantages and Limitations. The main advantage of sludge drying
beds over other types of sludge dewatering is the relatively low
cost of construction, operation, and maintenance.
Its disadvantages are the large area of land required and long
drying times that depend, to a great extent, on climate and
weather,
Operational Factors. Reliability: Reliability is high with
favorable climatic conditions, proper bed design and care to
avoid excessive or unequal sludge application. If climatic
conditions in a given area are not favorable for adequate drying,
a cover may be necessary.
Maintainability: Maintenance consists basically of periodic
removal of the dried sludge. Sand removed from the drying bed
with the sludge must be replaced and the sand layer resurfaced.
The resurfacing of sludge beds is the major expense item in
sludge bed maintenance, but there are other areas which may
require attention. Underdrains occasionally become clogged and
have to be cleaned. Valves or sludge gates that control the flow
of sludge to the beds must be kept watertight. Provision for
drainage of lines in winter should be provided to prevent damage
from freezing. The partitions between beds should be tight so
that sludge will not flow from one compartment to another. The
outer walls or banks around the beds should also be watertight,
Solid Waste Aspects: The full sludge drying bed must either be
abandoned or the collected solids must be removed to a landfill.
These solids contain whatever metals or other materials were
settled in the clarifier. Metals will be present as hydroxides,
oxides, sulfides, or other salts. They have the potential for
leaching and contaminating ground water, whatever the location of
the semidried solids. Thus the abandoned bed or landfill should
include provision for runoff control and leachate monitoring.
Demonstration Status. Sludge beds have been in common use in
both municipal and industrial facilities for many years.
However, protection of ground water from contamination has not
always been adequate.
15. Ultrafiltration
Ultrafiltration (UP) is a process which uses semipermeable
polymeric membranes to separate emulsified or colloidal materials
suspended in a liquid phase by pressurizing the liquid so that it
permeates the membrane. The membrane of an ultrafliter forms a
molecular screen which retains molecular particles based on their
differences in size, shape, and chemical structure. The membrane
permits passage of solvents and lower molecular weight molecules,
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At present, an ultrafilter is capable of removing materials with
molecular weights in the range of 1,000 to 100,000 and particles
of comparable or larger sizes.
In an ultrafiltration process, the feed solution is pumped
through a tubular membrane unit. Water and some low molecular
weight materials pass through the membrane under the applied
pressure of 2 to 8 atm (10 to 100 psig). Emulsified oil droplets
and suspended particles are retained, concentrated, and removed
continuously. In contrast to ordinary filtration, retained
materials are washed off the membrane filter rather than held by
it. Figure VII-12 represents the ultrafiltration process.
Application. Ultrafiltration has potential application to metal
molding and casting industry plants for separation of emulsified
oils from a variety of waste streams, most notably die casting
wastewater. Over 100 such units now operate in the United
States, treating emulsified oils from a variety of industrial
processes. Capacities of currently operating units range from a
few hundred gallons a week to 50,000 gallons per day.
Concentration of oily emulsions to 60 percent oil or more is
possible. Oil concentrates of 40 percent or more are generally
suitable for incineration, and the permeate can be treated
further and in some cases recycled back to the process. In this
way, it is possible to eliminate contractor removal costs for oil
from some oily waste streams.
The permeate or effluent from the ultrafiltration unit is
normally of a quality that can be reused in industrial
applications or discharged directly. The concentrate from the
ultrafiltration unit can be disposed of as any oily or solid
waste.
Advantages and Limitations. Ultrafiltration is sometimes an
attractive alternativeto chemical treatment because of lower
capital equipment, installation, and operating costs, very high
oil and suspended solids removal, and little required
pretreatment. It places a positive barrier between pollutants
and effluent which reduces the possibility of extensive pollutant
discharge due to operator error or upset in settling and skimming
systems. Alkaline values in alkaline cleaning solutions can be
recovered and reused in process.
A limitation of ultrafiltration for treatment of process
effluents is its narrow temperature range (18° to 30°C) for
satisfactory operation. Membrane life decreases with higher
temperatures, but flux increases at elevated temperatures.
Therefore, surface area requirements are a function of
temperature and become a trade-off between initial costs and
replacement costs for the membrane. In addition, ultrafiltration
cannot handle certain solutions. Strong oxidizing agents,
solvents, and other organic compounds can dissolve the membrane.
Fouling is sometimes a problem, although the high velocity of the
wastewater normally creates enough turbulence to keep fouling at
a minimum. Large solids particles can sometimes puncture the
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membrane and therefore must be removed by gravity
filtration prior to the ultrafiltration unit.
settling or
Operational Factors.
Reliability: The
is dependent on the
reliability of an
proper filtration,
ultrafiltration system
settling or other treatment of incoming waste streams to prevent
damage to the membrane. Careful pilot studies should be done in
each instance to determine necessary pretreatment steps and the
exact membrane type to be used.
Maintainability: A limited amount of regular maintenance is
required for the pumping system. In addition, membranes must be
periodically changed. Maintenance associated with membrane
plugging can be reduced by selection of a membrane with optimum
physical characteristics and sufficient velocity of the waste
stream. It is occasionally necessary to pass a detergent
solution through the system to remove an oil and grease film
which accumulates on the membrane. With proper maintenance,
membrane life can be greater than twelve months,
Solid Waste Aspects: In the metal molding and casting category,
ultrafiltration is used primarily to remove or recover liquid
constituents of process wastewaters. The system reject
(concentrated oils) could be recovered, reprocessed, or removed
for disposal.
Demonstration Status. The ultrafiltration process is well
developed and commercially available for treatment of wastewater
or recovery of certain high molecular weight liquid and solid
contaminants. This technology is demonstrated in the aluminum
die casting process segment.
IN-PROCESS POLLUTION CONTROL TECHHIQUES
In general, the most cost-effective pollution reduction
techniques available to any industry are those which prevent
completely the entry of pollutants into process wastewater or
reduce the volume of wastewater requiring treatment. These "in-
process" controls can increase treatment effectiveness by
reducing the volume of wastewater to treatment, resulting in more
concentrated waste streams from which they can be more completely
removed, or by eliminating pollutants which are not readily
removed or which interfere with the treatment of other
pollutants. They also frequently yield economic benefits in
reduced water consumption, decreased waste treatment costs and
decreased consumption or recovery of process materials.
Generally Applicable In-Process Control Techniques
Techniques
from most
wastewater
reduction,
air pollution
housekeeping.
which may be applied to reduce pollutant discharges
metal molding and casting subcategories include
segregation, water recycle and reuse, water use
process modification (including flow reduction and dry
control), and improved plant maintenance and
Effective in-process control at most plants may
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entail a combination of several of the above techniques.
Wastewater Segregation - The segregation of wastewater streams is
an important element in implementing pollution control in the
metal molding and casting category. Separation of noncontact
cooling water from process wastewater prevents dilution of the
process wastes and maintains the character of the noncontact
stream for subsequent reuse or discharge.
Mixing process wastewater with noncontact cooling water increases
the total volume of process wastewater. This has an adverse
effect on both treatment performance and cost. The increased
volume of wastewater increases the size and cost of treatment
facilities. Since a given treatment technology has a specific
treatment effectiveness and can only achieve certain discharge
concentrations of pollutants, the total mass of pollutants which
is discharged is increased with dilution by noncontact cooling
water because the total volume of water discharged increases.
Thus a plant which segregates noncontact cooling water and other
nonprocess waters from process wastewater will almost always
achieve a lower mass discharge of pollutants while substantially
reducing treatment costs.
Metal molding and casting plants commonly produce multiple
process and nonprocess wastewater streams. Nonprocess streams
include wastewater streams that are reusable after little or no
treatment. Reusable waters are most often noncontact cooling
waters. This water is usually uncontaminated and can be recycled
in a closed indirect cooling configuration, or it can be used as
makeup for process water. Noncontact cooling water is commonly
recycled for reuse in the metal molding and casting industry.
Wastewater Recycle and Reuse - The recycle or reuse of process
wastewater is a particularly effective technique for the
reduction of both pollutant discharges and treatment costs. The
term "recycle" is used to designate the return of process
wastewater, usually after some treatment, to the process or
processes from which it originated, while "reuse" refers to the
use of wastewater from one process in another. Both recycle and
reuse of process wastewater are presently practiced at metal
molding and casting plants, although recycle is more extensively
used. Process water recycle is employed in all metal molding and
casting process segments except investment casting. Table VII-4
shows the demonstration status of recycle in metal molding and
casting process segments.
Both recycle and reuse are frequently possible without extensive
treatment of the wastewater; process pollutants present in the
waste stream are often tolerable {or occasionally even
beneficial) for process use. Recycle or reuse in these instances
yields cost savings by reducing the volume of wastewater
requiring treatment. Where treatment is required for recycle or
reuse, it is frequently considerably simpler than the treatment
necessary to achieve effluent quality suitable for release to the
environment. Treatment prior to recycle or reuse observed in
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present practice is generally restricted to simple settling or
chemical addition for scale and corrosion control. Since these
treatment practices are less costly than those used prior to
dischargef economic as well as environmental benefits are usually
realized. In addition to these in-process recycle and reuse
practices, some plants return part or all of the treated effluent
from an end-of-pipe treatment system for further process use.
The rate of water used in wet air scrubbers is determined by the
requirement for adequate contact with the air being scrubbed and
not by the mass of pollutants to be removed. As a result,
wastewatet streams from once-through scrubbers are
characteristically very dilute and high in volume. These streams
can be recycled extensively without treatment or after simple
settling with no deleterious effect on scrubber performance.
Wastewater from contact cooling operations also may contain low
concentrations of pollutants which do not interfere with the
recycle of these streams. In some cases, recycle of contact
cooling water with no treatment is observed while in others,
provisions for heat removal in cooling towers or closed heat
exchangers is required,
To confirm the recycle rates reported as currently achieved by
metal molding and casting plants surveyed, and in response to
industry comments pertaining to recycle water chemistry, the
Agency developed a recycle water chemistry model. The water
chemistry model is based on a mass balance around a generalized
wastewater recycle system depicted in Figure VII-13. Input
variables to the model include make-up water quality, pollutant
mass addition rate by the metal molding and casting process,
treatment system performance, and sludge moisture content. EPA
used the water chemistry model to evaluate the following:
o The scaling and corrosion tendencies of foundry
wastewaters at varying levels of recycle.
o The appropriate levels of recycle attainable based on a
theoretical analysis of recycle water chemistry.
o The recycle system control options that could be added
to allow foundry processes to achieve high or complete
recycle rates.
o The effect of different make-up water qualities on the
ability of specific foundry processes to achieve high
or complete recycle rates.
o The sensitivity of maximum recycle rate to sludge
moisture content.
o The sensitivity of maximum recycle rate to co-treatment
of wastewater (central treatment).
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o The sensitivity of maximum recycle rate to recycle loop
treatment efficiency.
The development and execution of trial runs of the water
chemistry model, as well as the data base supporting the model
inputs/ are documented in a report entitled "Technical Evaluation
of High-Rate and Complete Recycle Systems for Foundry Industry
Process Wastewater." That report is located in Section 22.12 of
the record of the metal molding and casting rulemaking, A
summary of the findings obtained by running the model under
various input conditions is attached as Appendix B.
In general, based on the findings of the recycle model
sensitivity analyses, the Agency has been able to confirm as
achievable the recycle rates reported by metal molding and
casting plants. In addition, the Agency has determined that:
a. With proper chemical control, make-up water quality
does not have a significant influence on achievable
recycle rates.
b. The solids content of well-dewatered sludges has no
measurable impact on ability to recycle. For
undewatered sludges at or below 5 percent solids, any
impact would be positive (i.e., tend to increase
recycle rates).
c. High rate recycle is achievable at plants employing
central treatment.
Water Use Reduction - The volume of wastewater discharge from a
plant or specific process operation may be reduced by simply
eliminating excess flow and unnecessary water use. Often this
may be accomplished with no change in the manufacturing process
or equipment and without any capital expenditure. A comparison
of the volumes of process water used in and discharged from
equivalent process operations at different plants or on different
days at the same plant indicates substantial opportunities for
water use reductions. Additional reductions in process water use
and discharge may be achieved by modifications to process
techniques and equipment.
The practice of shutting off process water flow during periods
when production units are not operating and of adjusting flow
rates during periods of low production can prevent much
unnecessary water use. Water may be shut off and controlled
manually or through automatically controlled valves. Manual
adjustments have been found to be somewhat unreliable in
practice; production personnel often fail to turn off manual
valves when production units are shut down and tend to increase
water flow rates to maximum levels "to ensure good operation"
regardless of production activity. Automatic shut-off valves may
be used to turn off water flows when production units are
inactive. Automatic adjustment of flow rates according to
production levels requires more sophisticated control systems
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incorporating production rate sensors.
Contract Hauling
Contract hauling refers to the industry practice of contracting
with a firm to collect and transport wastes for off-site
disposal. This practice is particularly applicable to low-
volume, high concentration waste streams. Examples of such waste
streams in the metal molding and casting industry are aluminum
and zinc die casting waters.
The DCP data identified several waste solvent haulers, most of
whom haul solvent in addition to their primary business of
hauling waste oils. The value of waste solvents seems to be
sufficient to make waste solvent hauling a viable business.
Telephone interviews conducted during the development of metal
finishing regulations indicate that the number of solvent haulers
is increasing and that their operations are becoming more
sophisticated because of the increased value of waste solvent,
In addition, a number of chemical suppliers include waste hauling
costs in their new solvent price. Some of the larger solvent
refiners make credit arrangements with their clientele; for
example, it was reported that one supplier returns 50 gallons of
refined solvent for every 100 gallons hauled.
Lubricating 0,il_ Recovery
The recycle of die lube oils is a common practice in the
industry. The degree of recycle is dependent upon any in-line
treatment (e.g., filtration to remove metal fines and other
contaminants), and the useful life of the specific oil in its
application. Usually, this involves continuous recycle of the
oil, with losses in the recycle loop from evaporation, oil
carried off by the metal product, and minor losses from in-line
treatment. Some plants periodically replace the entire batch of
oil once its required properties are depleted. In other cases, a
continuous bleed or blowdown stream of oil is withdrawn from the
recycle loop to maintain a constant level of oil quality. Fresh
make-up oil is added to compensate for the blowdown and other
losses, and in-line filtration is used between cycles.
Dry Mr^ Pollution Control Devices
The use of dry air pollution control devices allows the
elimination of waste streams with high pollution potential, i.e.,
waste streams from wet air pollution control devices. However,
the choice of air pollution control equipment is complicated, and
sometimes a wet system is the necessary choice. The important
difference between wet and dry devices is that wet devices
control gaseous pollutants as well as particulates.
Wet devices may be chosen over dry devices when any of the
following factors are found: (1) the particle size is
predominantly under 20 microns, {2} flammable particles or gases
are to be treated and there is minimal combustion risk, {3} both
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vapors and particles are to be removed from the carrier medium
(4) the gases are corrosive and may damage dry air pollution
control devices, and (5) the gases are extremely hot and can only
be cooled using a spray cooler or other wet device.
Equipment for dry control of air emissions includes cyclones, dry
electrostatic precipitators, fabric filters, and afterburners.
These devices remove particulate matter, the first three by
entrapment and the afterburners by combustion.
Afterburner use is limited to air emissions consisting mostly of
combustible particles. Characteristics of the particulate-laden
gas which affect the design and use of a device are gas density,
temperature, viscosity, flammability, corrosiveness, toxicityr
humidity, and dew point. Particulate characteristics which
affect the design and use of a device are particle size, shape,
density, resistivity, concentration, and other physiochemical
properties.
Proper application of a dry control device can result in
particulate removal efficiencies greater than 99 percent by
weight for fabric filters, electrostatic precipitators, and
afterburners, and up to 95 percent for cyclones.
Common wet air pollution control devices are wet electrostatic
precipitators, Venturi scrubbers, and packed tower scrubbers.
Collection efficiency for gases will depend on the solubility of
the contaminant in the scrubbing liquid. Depending on the
contaminant removed, collection efficiencies usually approach 99
percent for particles and gases.
Many metal molding and casting plants report the use of dry air
pollution controls for melting furnace, dust collection, and
grinding operations.
Good Housekeeping
Good housekeeping and proper equipment maintenance are necessary
factors in reducing wastewater loads to treatment systems.
Control of accidental spills of oils, process chemicals, and
wastewater from washdown and filter cleaning or removal can aid
in maintaining the segregation of wastewater streams. Curbed
areas should be used to contain or control these wastes.
Leaks in pump casings, process piping, etc., should be minimized
to maintain efficient water use. One particular type of leakage
which may cause a water pollution problem is the contamination of
noncontact cooling water by hydraulic oils, especially if this
type of water is discharged without treatment.
Good housekeeping is also important in chemical, solvent, and oil
storage areas to preclude a catastrophic failure situation.
Storage areas should be isolated from high fire-hazard areas and
arranged so that if a fire or explosion occurs, treatment
facilities will not be overwhelmed nor excessive groundwater
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pollution caused by large quantities of chemical-laden fire-
protection water,
DEVELOPMENT OF CONTROL AND TREATMENT OPTIONS
The first part of this section described control and treatment
technologies that are applicable to the metal molding and casting
(foundry) category. During the development of the metal molding
and casting guideline/ these individual control and treatment
technologies were combined into five different treatment trains,
or technology options. These five options cover a broad range of
costs and pollutant removal capabilities. Model technologies for
BPT, BAT, NSPS, PSES, and PSNS for each subcategory were chosen
from these options after detailed consideration of such factors
as costs of pollutant removal, effluent reduction benefits of
pollutant removal, demonstration of the technology on foundry
wastewaters, air quality impacts, solid waste generation, and
water and energy consumption. Some technologies not included in
the options, such as second stage precipitation with sulfide,
also were considered.
This second part of Section VII describes the five treatment
options. Additional information is also provided on the
technologies included in each option. The development of
treatment effectiveness concentrations for each option is then
discussed, and the calculation of the long-term average and the
one-day maximum and monthly average concentrations developed for
use in the establishment of effluent limitations and standards is
explained.
Treatment Option !_ (Recycle and Simple Settle)
Option 1 consists of high-rate recycle of all metal molding and
casting wastewater, followed by simple gravity settling of the
blowdown. Figure VII-14 is a block diagram of the Option 1
treatment train. Inside the recycle loop, an appropriately sized
settling device is included to prevent excessive buildup of
suspended solids in the recycled water. In those process
segments where available data indicate that treatable levels of
oil and grease are present in the untreated wastewater, a surface
skimmer removes oil that has risen to the surface of the water in
the tank. All sludges produced in settling and oils collected by
skimming both inside and outside of the recycle loop are removed
by a licensed contractor. Acid is added prior to recycle to
control scale formation inside the* recycle loop for all segments
except aluminum investment casting, copper investment casting,
and magnesium dust collection, where caustic is added to prevent
corrosion because raw wastewaters in these three process segments
have a low pH.
Cooling towers are required in most copper and ferrous casting
quench, mold cooling, and direct chill casting segments and plant
sizes, as well as zinc mold cooling. In these processes, water
is used for purposes of heat transfer from molds or castings.
The temperature of the water is raised each time it is used and
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the limited cooling that occurs during the course of settling and
recycle is not sufficient for maintenance of high-rate recycle.
Cooling towers must be employed to maintain the recycled water at
the proper temperature. Cooling towers were not provided in
aluminum process segments, in zinc casting quench, or smaller
model plant sizes in copper casting quench (<10 employees) and
ferrous casting quench (10-49 employees) because it was
determined that in these segments, residence time in the settling
device is sufficient to provide the necessary cooling.
Treatment of the blowdown includes simple gravity settling in
either a batch or continuous mode, depending on such factors as
the flow rate and solids loading of the blowdown. In the case of
extremely high flows and solids loadings, a clarifier is used in
place of a settling tank. Dewatering of clarifier underflow
sludge for larger plant sizes is accomplished by a vacuum filter
in the copper direct chill casting {>250 employees), copper mold
cooling (100-249 employees), and ferrous wet sand reclamation
(>250 employees), where the high volumes of sludge produced make
dewatering prior to contractor removal of the dewatered sludge
more economical than contractor removal of the undewatered
sludge.
Additional oil skimming is included in the clarification step in
those process segments where available data indicate that
treatable levels of oil and grease are present.
Treatment Option 2^ (Recycle, Lime and Settle)
Option 2 consists of the Option 1 treatment train with the
addition of lime and polymer to the blowdown prior to settling.
These chemicals facilitate the precipitation and flocculation of
dissolved metals, which would not be removed by simple settling.
Oil skimming is retained in all segments where skimming was
present at Option 1, In addition, chemical emulsion breaking is
included for the aluminum and zinc die casting segments, where
emulsified oils are known to be present in the raw wastewater
discharges. Option 2 also includes chemical oxidation of phenol
by the addition of potassium permanganate in the following
segments: aluminum and zinc die casting; aluminum, copper, and
ferrous dust collection; all melting furnace scrubber segments;
and ferrous wet sand reclamation. These are the 10 segments
whose average raw waste contains treatable levels of phenols.
Figure VII-15 is a block diagram of the Option 2 treatment train.
For the aluminum and zinc die casting segments, Option 2 consists
of treatment of the entire wastewater stream by sequential
emulsion breaking, oil skimming, and potassium permanganate
oxidation prior to lime and polymer addition and settling. As
depicted in Figure VII-16, this treatment train is followed by
high-rate recycle to the process. All treatment steps are
performed inside the recycle loop for these two process segments
to ensure that the duality of the recycled water is sufficient
for use in the process.
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Treatment Option _3 (Recycle, Lime, Settle, and Filter)
Option 3 is the addition of filtration to the Option 2 treatment
train to provide additional removal of solids remaining after
precipitation and settling. Figure VII-17 is a block diagram of
the Option 3 treatment train. Depending on the flow rate of the
model plant blowdown, a cartridge filter, multimedia filter or
pressure filter is employed. The flow ranges in which each type
of filter would be used were determined by performing an economic
analysis. The annualized cost of purchasing and operating each
type of filter was determined at each flow rate. Breakpoint
flows, where one type of filter becomes less expensive to
operate, were obtained at 4 gpm and at 125 gpm. As a result of
this analysis, cartridge filters are used on wastewater flows up
to 4 gpmf multimedia filters on flows from 4 gpm to 125 gpm, and
pressure filters on flows greater than 125 gpm.
Option 3 for the aluminum die casting and zinc die casting
process segments consists of Option 2 treatment inside the
recycle loop, with filtration performed only on the blowdown
prior to discharge. This arrangement is shown in Figure VII-18.
Treatment Option _4
At Option 4, the final effluent from the Option 3 treatment train
is subjected to carbon adsorption treatment for removal of
residual organic pollutants. The Option 4 treatment train for
all process segments except aluminum die casting and zinc die
casting is presented in Figure VII-19. The Option 4 treatment
train for the two die casting segments is presented in Figure
vir-20.
Treatment Option 5_
Option 5 is similar to Option 1 but complete recycle is achieved
and thus there is no blowdown treatment. Complete recycle is
maintained using the same techniques used to maintain high rate
recycle at the other options: settling {and surface skimming in
the same process segments as Option 1), pH adjustment as
necessary to prevent scaling or corrosion, and cooling towers
where required. Figure VII-21 presents the Option 2 treatment
train.
Additional Options Considered
In addition to these five options, two options were considered
which provide less overall pollutant removal than Options 1 and
2. The first is simple settling and discharge of the full waste
stream generated, with no recycle. The second is chemical
precipitation, settling, and discharge of the full waste stream
generated, with no recycle. These options are essentially
Options 1 and 2 without recycle. These options were only
considered when the Agency believed that the cost of Option 1
treatment might cause significant adverse economic impacts and
where the costs of these non-recycle options were lower than the
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costs associated with Option 1. They were not given serious
consideration for the final regulation because the Economic
Impact Analysis did not project significant adverse impacts.
The Agency also considered including in the lime and settle
treatment train (Options 2, 3, and 4) enhanced metals removal
prior to filtration. This is achieved through the addition of
chemicals to effect metal sulfide or metal carbonate
precipitation. The Agency did not select sulfide or carbonate
precipitation as the technology basis for the final regulation.
The Agency determined that filtration is an effective and less
costly control option for enhanced metals removal than second-
stage precipitation and clarification. Cost and treatment
effectiveness data on carbonate precipitation and on sulfide
precipitation may be found in the public record for this
rulemaking.
DEVELOPMENT OF TREATMENT EFFECTIVENESS VALUES
Treatment effectiveness values for the five treatment options as
applied to metal molding and casting wastewaters are based
wherever possible on actual performance data from metal molding
and casting plants. In some cases, where such performance data
are not available/ performance data from other similar industrial
categories were used after a determination was made that these
performance data are applicable to metal molding and casting
industry wastewaters. In this section/ the source of the
treatment effectiveness values for each pollutant or class of
pollutants is discussed separately for each treatment option.
Treatment Option ^
Option 1 treated effluent concentrations are based for the most
part on actual performance data from metal molding and casting
plants. Because Option 1 was not selected as the basis for any
limitations or guidelines applicable to the metal molding and
casting category, the development of specific limitations values
such as a daily maximum or monthly average was not necessary.
The derivation of Option 1 treatment effectiveness concentrations
that were used in benefits calculations is discussed below.
Details of these derivations may be found in the record.
Total Suspended Solids 1_TSS_)_: Option 1 treated effluent TSS
concentrations were assumed/ for purposes of calculating waste
loads and pollutant removals, to be either 20 mg/1 or 30 mg/1 for
each process segment, depending on the solids loading of the raw
waste. If the concentration of total suspended solids in the raw
waste was 100 mg/1 or less/ the effluent TSS concentrations was
assumed to be 20 mg/1. Similarly, if the total suspended solids
in the raw waste was greater than 100 mg/1, the effluent TSS
concentration was assumed to be 30 mg/1. These assumptions were
based on TSS concentrations observed at metal molding and casting
plants and at plants in other industrial categories that have
simple settling.
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Metals; The simple settle treatment effectiveness value for each
metal was derived by assuming that 1 percent of the metal present
in the raw waste was in dissolved form, and would be concentrated
in the recycle loop and remain untreated by simple settle
technology. The remaining metal was assumed to be particulate
and undergo a similar percent reduction as achieved for TSS.
Oil and Grease: The metal molding and casting simple settle data
base was reviewed for oil and grease data. As a result of this
review, an average value of 5 mg/1 as chosen as the long-term
Option 1 treatment effectiveness value for oil and grease. This
value is well-supported by oil and grease removals currently
demonstrated in the foundries category.
Toxic Organic Pollutants^ Concentrations of toxic organics and
4-AAP phenols in Option 1 effluents were calculated using removal
rates presented in Exhibit 14 of the report entitled "Control of
Toxic Organic Pollutants." That report can be found in Section
22.12 of the record for this rulernaking.
Treajtment Opt_ion 2^
At proposal, the Agency used the Combined Metals Data Base (CMDB)
as the basis for establishing proposed treatment effectiveness
concentrations reflective of proper lime and settle treatment.
The CMDB is a data base from well-operated lime and settle
treatment systems employed by plants in various metals industries
that has been used to establish lime and settle treatment
effectiveness for several industrial point source categories.
Numerous commenters criticized the Agency's use of the Combined
Metals Data Base, stating that limitations should be based on
data from treatment systems applied to metal molding and casting
wastewaters.
In response to these comments, the Agency developed a metal
molding and casting treatment effectiveness data base for use in
establishing treatment effectiveness values reflective of high
rate recycle and lime and settle treatment {Option 2) as applied
to metal molding and casting wastewaters. The data base was
assembled from two sources: (1) data from EPA sampling efforts
at plants employing well-operated lime and settle systems
treating metal molding and casting wastewaters, and (2) discharge
monitoring reports (DMRs) from metal molding and casting
facilities.
Two levels of screening were performed to ensure that all data
included in the metal molding and casting data base were derived
from well-operated lime and settle treatment. The first level
was intended to confirm that the plant's treatment system was
indeed lime and settle, and that it was properly operated. At
this level, each plant was considered separately; if it could not
be confirmed that data from the plant were derived from well-
operated lime and settle treatment, then none of the data from
that plant were considered further. The second level of
screening focused on individual data points rather than plant
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practices or characteristics. In this level, all data points
were subjected to a second set of screening criteria intended to
eliminate data representing plant upsets, excursions, or
reporting errors. These two levels of screening are explained in
detail below.
In the first level, the treatment system at each plant was first
compared with a set of criteria that indicate conditions
necessary for the proper operation of lime and settle treatment.
If the plant did not meet these screening criteria, then none of
the data from that plant were considered further for inclusion in
the metal molding and casting data base. These criteria are
listed below:
1. The plant must have hydroxide addition for metals
precipitation followed by simple settling.
2. More than 50 percent of the wastewater entering the
treatment system must be metal molding and casting
process wastewater.
3. Not more than 25 percent of the total flow to the
treatment system may be noncontact cooling water,
4. Sufficient chemical addition must be performed to
facilitate metals precipitation. The pH must be
consistently maintained between 7.0 and 10.0 standard
units.
5. Sedimentation units must be effective; this means that
the average effluent TSS levels must be maintained
below 50.0 mg/1.
6. If a plant did not practice any degree of recycle, or
had unrepresentative, low raw waste loads, then the
data from that plant were not included in the data
base.
7. Plant data were eliminated wherever improper treatment
system operation was identified. This category
includes plants where problems were noted during
sampling, or where plant-supplied records from the
wastewater treatment plant show that there were
extended periods of upset during the times when data
were obtained.
A number of plant data sets were excluded from the final metal
molding and casting data base as a result of this review.
Section 22.58 of the record for this rulemaking includes a list
of all the plant data sets reviewed, and identifies those
excluded from further analysis for failure to meet one or more of
the screening criteria, as well as those retained and subjected
to further review and analysis.
The cases where a plant appeared to have well-operated lime and
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settle treatment, but the only data available for that plant were
DMR data, a further effort was made to confirm the data by
comparing the long-term DMR data with EPA sampling data from the
same plant. Long-term DMR data were considered confirmed in
cases where (1) EPA short-term sampling data were available for
the same plant andr preferably, the same period of time was
represented by both EPA and DMR data, and (2) where the short-
term EPA data were consistent with the long-term DMR data.
There were four plants with lime and settle treatment that
appeared to be well-operated for which usable DMR data were
available, but not confirmed with EPA data. After the February
1985 Notice of Data Availability, the Agency sent letters to
these four plants soliciting additional data and information
designed to enable the Agency to determine whether the data
reflected proper operation of the treatment system, and whether
the plant's wastewaters were characteristic of metal molding and
casting wastewaters after high rate recycle. To this end, EPA
requested that each plant submit data from three days of sampling
and analysis of its treatment system influent and effluent.
The data made available by these plants were nc collected by
personnel directly under the supervision of the Agency. However,
the Agency's requests included detailed descriptions of the data
and documentation required, as well as detailed procedures by
which it was to be gathered. Further, the metal molding and
casting plant personnel who gathered the data were contacted by
the Agency and the procedures were clarified and modified as
necessary during the sampling effort to ensure that the most
representative data were obtained.
Based upon the data and documentation received, the Agency
determined that DMR data for three of the four plants could be
considered confirmed and used in the development of effluent
limitations and standards. These additional sampling data
gathered to confirm the DMR data were also included in the data
base and considered equivalent to the short-term EPA sampling
data from other plants. Data from the fourth plant could not be
used because the influent to the plant's treatment system
contained excessive quantities of noncontact cooling water
commingled with process wastewater.
The result of this first level of screening and review was a data
base consisting of data from three sources; (1) EPA sampling
data, (2) confirmed DMR data, and {3} self-sampling data gathered
and submitted by the three plants described above. All of these
data had been determined to originate from plants with well-
operated lime and settle treatment.
The second level of screening focused on individual data points
and was intended to eliminate points representing plant upsets,
excursions, or reporting errors. During this screening, all data
were subjected to three criteria involving (1) treatment system
pH, (2) effluent levels of suspended solids, and (3) influent
pollutant levels. These criteria are explained in detail below.
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The pH range of 7.0-10.0 was chosen to ensure that dissolved
metals of concern are precipitated from solution as hydroxides.
Both theoretical pH versus solubility relationships and data for
metals-bearing wastewaters confirm that pH must be controlled to
ensure precipitation and subsequent removal with TSS. Based on
the open literature and on treatability studies, the optimum pH
range in which to operate lime and settle technology for optimum
precipitation of the metals of concern in this category is
believed to be pH 9.0 to 10.0. However, the optimum pH range can
vary, depending on the specific metals present and their
solubilities. Therefore, a relatively broad pH range has been
used to cover most metals of concern, and to account for a
variety of raw wastewater matrices and treatment system operating
characteristics present in the category.
The raw wastewater matrices for the metal molding and casting
industry and other related metals industries exhibit
settleability characteristics which allow for rapid separation of
solids to low effluent TSS concentrations (less than 50 mg/l}»
This fact is supported by treatability studies and by DMR data
from the metal molding and casting industry. Treatment systems
which exhibit long-term average TSS concentrations higher than 50
mg/1 can nearly always be found to have poor control of solids or
to be overloaded. Similarly, individual TSS effluent
concentrations in excess of 50 mg/1 are symptomatic of upset
conditions, such as hydraulic overload by slugs of process
wastewater or stormwater. In addition, an examination of the
metal molding and casting data base confirms that optimum removal
of metals and other pollutants is achieved when TSS is maintained
below 50 mg/1. Therefore, the Agency has utilized a long-term
average TSS concentration of 50 mg/1 as a screening criterion to
assist in identifying and excluding from the treatment
effectiveness data base plants that are poorly designed or
operated. This criterion also is used to identify individual
data points within a plant's data set which represent short-term
operational problems. In cases where excursions occur, they
often result in treated effluent concentrations approaching or
exceeding raw waste concentrations, in some cases for extended
periods of time, until corrective measures are taken or the
contributing circum stances cease to exist. Accordingly, data
for these periods were not considered in the development of
effluent limitations and standards.
Effluent data were deleted where influent data were missing and
where corresponding influent values were less than 0.10 mg/1.
This criterion was used to ensure that pollutant removals across
treatment could be identified and that removals actually were
occurring.
Excursions in data can also occur in cases where documentation
was not available from plants or could not be secured by EPA to
identify the contributing circumstances. Examples of such
circumstances are laboratory analytical and/or reporting errors,
in-plant spills or leaks, collection of unrepresentative samples,
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malfunctions. Therefore/ selected data points were
deleted based on engineering judgment where values reported
obviously were aberrant but no other documentation were available
or could be secured. In most cases these values also were
clearly statistical outliers compared to the balance of the data
sets being considered.
The data base remaining after the second level of screening
consisted of long-term DHR and short-term sampling data from
plants with well-operated lime and settle treatment, on days
where no plant upsets were occurring. This is the data base used
in hhe development of final effluent limitations and standards.
The derivation of the limitaticns guidelines and standards is
described in the following sections.
Analysis of_ the Data Base
Long-term average, maximum monthly average, and maximum daily
concentration limitations were calculated from the lime and
settle treatment effectiveness data for use in those segments
where Option 2 was chosen as the technology basis for
regulations. The basic assumption underlying the determination
of these concentrations is that the data for a particular
pollutant are lognormally distributed by plant. The lognormal
distribution has been found to provide a satisfactory fit to
effluent data in a wide range of industrial categories for a
variety of pollutants and usually provides a good approximation
for the distribution of treated effluent pollutant concentration
measurements.
Goodness-of-fit tests performed on the DMR data from each plant
can be found in Section 22.48 of the public record for this
rulemaking. The test results indicate that the use of the
lognormal distribution is consistent with these data, In a
majority of cases, the lognormal distribution was not rejected by
the Studentized Range Test. In addition, in almost all cases,
the data display the general lognormal shape which is
characterized by the mean being larger than the median and by
positive skewness. Goodness-of-fit tests were not applied to the
EPA metal molding and casting data because of the small sample
sizes per plant. Such data do not, in most cases, reject the
lognormal since the small data sets do not have much statistical
power to discern the difference between the logncrmal and other
distributional shapes.
The results of the goodness-of-fit tests, considered in light of
the prior successful use of the lognormal distribution to model
effluent data in other industrial categories, lead the Agency to
conclude that the lognormal distribution provides a satisfactory
fit to the metal molding and casting data.
In the case of the metal molding and casting data, a generalized
form of the lognormal distribution, known as the delta lognormal
(DLN) distribution, was used to model the data. This is the same
approach followed in the analysis of the combined metals data
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base (CHDB). The DLN models the data as a mixture of geros and
values above zero that are lognormally distributed. This
distribution is described in Chapter 9 of The Lognormal
Distribution/ by Aitchison and Brown, Cambridge University Press,
1963. The DLN was used because of the presence of observations
below the detection limit in data from some plants for certain
pollutants. Owen, W. J. and DeRouen, T. A. (1980), "Estimation
of the Mean for Lognormal Data Containing Zeros and Left Censored
Values," Biometrics 36, 707-719, recommended that when data
contain below detection limit values, the estimate of the mean is
most stable and has the lowest mean square error when the below
detection limit values are set to zero and the DLN distribution
is used to model the data. In cases where no observations below
the detection limit are present, the delta lognormal is
equivalent to the usual lognormal distribution.
The delta lognormal distribution (or delta distribution) is a
generalized form of the usual two parameter (y , a2 ) lognormal
distribution in which a proportion, , of the observations may be
zeroes and the non-zero values follow a lognormal distribution
with parameters u and a2, i.e., the logmean and logvariance of
the non-zero observations, respectively. If the random variable
X, representing daily pollution concentration measurements,
follows a delta distribution with parameters 6 , v t and o2 ,
denoted by X ~A (&rV r o2 ), the mean of the distribution, denoted
by E(X), is given by
E(X) = (1 - 6) exp( u + aV2),
where exp is e, the base of the natural logarithms. The quantile
of order q for the delta distribution is
where
|0 if q < 6
eap(u + v i o) if q ^ 5
and
Vqi= quantile or order q' of the normal distribution with
mean zero and variance one.
For q = .99, Xq is the 99th percentile of the delta
distribution. Estimates of the 99th percentile were used as the
basis for daily maximum treatment effectiveness concentrations.
The data from each plant for each pollutant were used to estimate
r & r M and o 2 for each plant as follows: Let XI, X2, . . ., Xn,
denote the n]_ observations from a particular plant that are
greater than the detection limit. Let np denote the number of
observations that are less than or equal to the detection limit.
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The total number of observations is thus n = no +• nj_. Then let
, i = 1, . . .f n\ denote the natural logarithms of the
Then 5, M , and a2 are estimated for each plant by
«-
n
/s
In the development of concentrations for use in calculating mass
limitations, the logmean, logvariance, and delta for the
combinations of EPA and DMR data were determined by taking the
averages of the logmean, logvariance, and delta across plants.
There is substantial theoretical support for this approach given
by W. G. Cochran, Sampling Techniques, 1963, 2nd edition, Wiley &
Sons, Theorem 5.1, page 89. As a practical matter the use of
sample size weighted averages as an alternative would be
equivalent to ignoring the information from the EPA-sampled
plants. This method of averaging across plants for each
pollutant gives equal consideration to the information from each
plant.
Thus, denoting the average 6, u , and a2across plants as 6 , y ,
and 6^, respectively, the estimates of the overall mean and the
99 percentile used to determine treatment effectiveness values
are
and
X(99 = eqj(u + v_i o)
where q1 - (.99 - D/(l
and
- quant ile or order q1 of the normal
(0, 1) distribution.
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Monthly limitations treatment effectiveness values are based on
the distribution of the average 10 daily samples. The approach
used to develop the monthly values assumes that the 10 daily
samples are drawn from the same distribution used to determine
the daily limitations, i.e./ the delta lognormal distribution.
The distribution of the average of the 10 daily values is
approximated by another delta lognormal distribution. The
parameters of the distribution of the average of 10 samples are
determined by the parameters of the underlying distribution of
daily values as shown in Section 22.58 of the public record of
this rulemaking. This approach has been used previously for the
determination of 10 day average concentrations presented in the
February, 1985 Notice of Availability for the metal molding and
casting industry, the 10 day average concentrations for the
metals processing industries based on the combined metals data
base (described in "A Statistical Analysis of the Combined Metals
Data Base," November, 1982, and "Revisions to Data and Analysis
of the Combined Metals Data Base," October, 1983) and for the
electroplating industry (see "Development Document for Existing
Source Pretreatment Standards for the Electroplating Point Source
Category," EPA 440/1-79-003, U.S. Environmental Protection
Agency, Washington, D.C., August, 1979). Although this
approximation is not theoretically correct, there is empirical
evidence that it is adequate and a computer simulation study
documented in the 1979 Electroplating Development document cited
above, demonstrated the adequacy of this approximation.
The parameter values for the distribution of X]_Q, the mean of 10
daily measurements, are as follows. The details of their
derivation are provided in Section 22.58 of the public record for
this rulemaking.
If f-he daily pollutant measurements Xj -£{6,p,o2}, where ~ A (<5,
u,o2) denotes delta lognormally distributed with probability of a
zero observation 6 , logmean u , and logvariance o2, then
Xn - A (6n r\in ' o2n } t where n = 10 in this case, then the
parameters 6n, pn, and a^ n in terms of the
parameters 6, u , and o2, are:
%~
i 0* - i m (U -
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Substituting estimates of the daily 6 , y , and 02 in the above
formulas for 6n , yn , and on results in estimated values denoted
by , , and , respectively. The 95th percentile of Xn can
then be estimated by
n + vq'n Sn)
.-
where q'n = -'•= • n , and vq1 is the qn quantile of a standard
normal {0,1} distribution. The mean or expected value of the
distribution of Xn is equivalent to the mean of the
distribution of daily measurements. The details of the
application of these formulas to the metal molding and casting
data are described in Sections 22,48 and 22.58 of the public
record of this rulemaking.
Met ajl s : The results of performing the calculations outlined
above on the EPA and confirmed DMR data to determine Option 2
treated effluent concentrations are shown in Table VII-5. The
results for individual plant data sets for each pollutant are
presented in Tables VII-6 through VII-11. Details of the
calculations supporting these concentrations are included in
Sections 22.48 and 22.58 of the public record for this
rulemaking .
As presented on Table VII-5 , the Agency calculated treatment
effectiveness concentrations based on data from ferrous plants
only, nonferrous plants only, and the combined ferrous and
nonferrous data sets. The results of the analyses performed on
the ferrous and nonferrous data as unique sets and as a combined
data set showed that, in general, pollutants in ferrous and
nonferrous wastewater are treatable to the same concentrations.
Therefore, EPA is basing the final treatment effectiveness
concentrations on the analysis of the combined set of ferrous and
nonferrous, EPA and confirmed DMR data, with the exceptions noted
below:
The long-term mean treated effluent concentration for copper,
based on the combined EPA and confirmed DMR data base, is 0.065
mg/1. This concentration is consistently achieved by lime and
settle treatment systems treating ferrous wastewaters. For this
reason, EPA is establishing the long-term mean copper
concentration for ferrous plants at 0.065 mg/1. In contrast, the
one copper casting plant in the EPA and confirmed DMR data set
had a long-term mean treated effluent copper concentration of
0.17 mg/1. Thus the limited data available on the performance of
well-designed and well-operated lime and settle treatment systems
treating wastewaters generated by nonferrous plants indicate that
nonferrous plants may not be able to achieve consistently
concentrations of 0.065 mg/1 using lime and settle treatment
technology. For this reason, the long-term mean copper
concentration for nonferrous plants is being set at 0.17 mg/1.
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The long-term mean treated effluent concentration for zinc based
on the combined effluent concentration data set is 0.27 mg/1.
This concentration is consistently achieved by lime and settle
treatment systems at the nonferrous plants. For this reason, EPA
is establishing the long-term mean zinc concentration for
nonferrous plants at 0.27 rag/1, The long-terra mean treated
effluent zinc concentration based on ferrous plant data only is
0.40 mg/1. Based on these data, the long-term raean of 0.27 mg/1
may not be consistently achieved by ferrous subcategory plants.
Thus, to ensure that ferrous plants employing lime and settle
treatment could achieve the treatment effectiveness
concentrations for zinc, EPA established the long-ten mean for
zinc at 0.40 mg/1.
Table VII-12 presents a tabular summary of the long-terra average,
maximum monthly average, and maximum day treatment effectiveness
concentrations for lime and settle treatment.
TSS, Oil and Grease, Total Phenol: The Agency determined
treatment effectiveness concentrations for TSS, oil and grease,
and total phenol using the same EPA and confirmed DMR data base
described above. These parameters measure specific bulk
properties of a wastewater matrix. However, based on available
data, EPA has determined that the treatability of these
parameters is not expected to vary significantly within
subcategories of the metal molding and casting category.
The long-term average treated effluent concentration of TSS for
both ferrous and nonferrous plants is 9 mg/1. The long-term
average concentration for ferrous plants is 10 mg/1. Based on
the available data from two nonferrous plants with well-operated
lime and settle treatment, the long-term average concentration
for nonferrous plants is 5 mg/1. Three of the six ferrous plants
in the data base have long-term average TSS concentrations of 10
mg/1, and two others have long-term averages of 13 mg/1 and 20
mg/1. On the basis of these observations, EPA has determined
that a long-term average concentration of 10 mg/1 for TSS is more
appropriate and consistently achievable by lime and settle
technology for both ferrous and nonferrous subcategories.
The long-term average treated effluent concentration of oil and
grease at ferrous and nonferrous plants in the EPA and confirmed
DMR data base is 5 mg/1. This average is based on the EPA and
confirmed DMR oil and grease data from the nine plants for which
such data were available. Five of these nine plants achieve the
maximum day limitation based on the long-term mean concentration
of 5 mg/1. This includes an aluminum and zinc die casting plant
which has high concentrations of emulsified oil and grease in raw
wastewaters.
The long-term average total phenol treated effluent concentration
for the ferrous and nonferrous subcategories is 0.20 mg/1 based
on incidental removal through lime and settle systems. Available
data indicate that many plants in this industry will be able to
achieve the total phenol limitations and standards without
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applying chemical oxidation. Three of the five planes from which
EPA and DMR phenol data were used in developing limitations
achieve the long-term average and maximum day concentrations for
phenol. In those cases where the total phenol limitations and
standards cannot be met using recycle and lime and settle
treatment alone, compliance can be attained through the use of
chemical oxidation. Chemical oxidation by addition of potassium
permanganate has been included as part of the model treatment
technology for all 10 process segments where the average phenol
concentration in the raw waste was at a treatable level.
The conclusion that metal molding and casting plants will be able
to achieve the total phenol limitations and standards is based on
data available from two independent bench-scale studies performed
on ferrous foundry wastewaters. In one study, total phenol
concentrations were reduced by 97.6 percent (from 1.1 mg/1 to
0.026 mg/1) using potassium permanganate oxidation followed by
lime and settle treatment. In the other study, phenol
concentrations were reduced by greater than 92 percent (from
0.123 mg/1 to <0.01 mg/1) using potassium permanganate oxidation.
Details of these studies may be found in Section 22.57 and 22.60
of the record for this rulemaking.
The bench-scale tests were intended to demonstrate that chemical
oxidation technology is effective in the removal of phenol from
metal molding and casting wastewater; data from these tests are
not intended to replace data from actual foundry wastewater
treatment systems. While every attempt was made to approximate
conditions in a foundry treatment system/ including the use of
foundry wastewater in the tests, the smaller volume of wastewater
used and the laboratory setting allowed for more carefully
controlled conditions than would be possible in an actual foundry
treatment system. It is possible that the percent reductions
achieved in the laboratory may be somewhat higher than those
achievable during actual chemical oxidation or treatment. Thus,
the concentration data that resulted from the studies were not
used as the basis for treatment effectiveness values; rather,
actual foundry sampling data were used. Nonetheless, the
achievability of the treatment effectiveness concentrations for
phenol is strongly supported by the bench-scale study results.
Toxic Organic Pollutants; In addition to toxic metals, TSS, oil
and grease, and total phenol, toxic organic pollutants are being
regulated in 22 process segments. These toxic organics are being
treated as a single pollutant parameter, total toxic organics or
TTO. For each process segment where it is being regulated, TTO
is defined separately as the list of all toxic organic pollutants
that were found in treatable concentrations in the raw
wastewaters of that segment. The TTO concentration limit for
each segment is then defined as the sum of the treatment
effectiveness concentrations for all pollutants on the list.
Toxic organic pollutant data were analyzed for each process
segment. Different organic pollutants were found at varying
concentrations in the raw wastewaters of each of the 22 process
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segments; the greatest number of pollutants and the highest
concentrations were found in the die casting, melting furnace
scrubber, and dust collection scrubber process segments,
To develop treatment effectiveness values for toxic organic
pollutants, the Agency reviewed treated effluent data for four
plants: (1) An aluminum and zinc die casting plant with a
central treatment system including emulsion breaking, oil
skimming, and lime and settle treatment operated on a batch
basis. (2) A ferrous plant with high rate recycle and a central
lime and settle treatment system with oil skimming. This
treatment system receives water from melting furnace scrubber,
slag quench, and dust collection processes. {3} An aluminum die
casting plant with recycle and central treatment including
emulsion breaking, oil skimming, and alum and settle. This
treatment system receives water from die casting, casting quench,
and melting furnace scrubber processes* (4) A ferrous plant with
treatment of dust collection process wastewaters. Treatment
consists of oil skimming and simple settling followed by high
rate recycle. Toxic pollutant sampling data for the two plants
that did not have lime addition were used in this analysis
because they employed mechanical oil and grease removal, in one
case preceded by emulsion breaking, and exhibited effective
removal of toxic organic pollutants.
For each toxic organic pollutant, the treated effluent
concentrations from these four plants were averaged, giving equal
weight to each plant, to obtain the Option 2 treatment
effectiveness concentration for that pollutant. Individual
treatment effectiveness values calculated in this manner range
from 0.01 mg/1 to 0.078 mg/1. It is noteworthy that this range
of average effluent concentrations was achieved by the die
casting plants, one of which had very high raw waste load
concentrations of toxic organic pollutants. This demonstrates
the achievability of the TTO limitation by plants with high raw
waste loads.
O.ll removal is an effective treatment for priority toxic organic
pollutants because priority organics tend to be much more soluble
in organic solvents than in water. Thus, they are much more
concentrated in the oil phase that is skimmed than in the treated
wastewater. The ratio of solubilities of a compound in oil and
water phases is called the partition coefficient. The logarithm
of the partition coefficients for 34 priority organic pollutants
in octanol and water are:
Log Octanol/Water
Organic Priority PolLutant Partition Coefficient
1. acenaphthene 4.33
4. benzene 2,13
7. chlorobenzene 2,84
11. 1,1,1-trichloroethane 2.17
13. 1,1-dichloroethane 1.79
15. 1,1,2,2-tetrachloroethane 2.56
18. bis{2-chloroethyl) ether 1.58
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23. chloroform 1.97
29, dichloroethylene 1.48
38. ethylbenzene 3.15
39. fluoranthene 5,33
44. methylene chloride 1.25
55. naphthalene 3.37
64. pentachlorophenol 5.01
65. phenol 1.48
66. bis(2-ethylhexyl) phthalate 8.73
67. butyl benzyl phthalate 5.80
68. di-n-butyl phthalate 5.20
70. diethyl phthalate 5.00
72. benzo(a)anthracene 5,61
73. benzo(a)pyrene 6.04
74. 3,4-benaofluoranthene 6.57
75. benzo(k)fluoranthene 6.84
76. chrysene 5.61
77* acenaphthylene 4.07
78. anthracene 4.45
79. benzo(ghi)perylene 7.23
Log Octanol/Water
Organic Priorj.ty^ Pollutant Partition Coefficient
80. fluorene 4.18
81. phenanthrene 4.46
82. dibenzo(a,h)anthracene 5.97
83. indeno(l,2f3-c,d)pyrene 7.66
84* pyrene 5.32
85. tetrachloroethylene 2.88
86. toluene 2.69
Treatability concentrations for organic pollutants that were not
detected in the raw waitewaters of the four metal molding and
casting plants for which data were available were estimated by
dividing all pollutants for which data were available into groups
of pollutants with similar octanol/water partition coefficients.
Toxic organic pollutants which had been detected in raw
wastewaters of metal molding and casting plants at treatable
concentrations, but for which treated effluent data were not
available, were assigned to one of the groups depending on their
partition coefficient; these pollutants were assumed to have a
treatability concentration equal to the mean effluent concentra
tion of all pollutants in that group. For some pollutants,
neither treated effluent sampling data nor literature values for
partition coefficients were available. In such cases, estimates
were calculated using a parallel method based on the compound's
solubility in water.
The long-term average effluent TTO concentration for each process
segment was determined by summing the treatment effectiveness
concentrations for each of the pollutants detected in treatable
concentrations in the raw waste of that process segment.
The statistically determined variability factors used to
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calculate the maximum monthly average and maximum one-day
limitations for oil and grease also were applied to the long-term
average TTO concentrations for each process segment to calculate
the maximum monthly average and maximum one-day TTO limitations.
Appendix A of this document includes a list of toxic organic
pollutants comprising the TTO limitations for each process
segment where TTO is regulated.
Table VII-13 lists all of the toxic organic pollutants that are
constituents of TTO in any process segment where TTO is
regulated. Treatment effectiveness values are also listed for
each pollutant.
The Agency has revised its approach to calculating TTO treatment
effectiveness concentrations. In the past, EPA has calculated
treated effluent TTO concentrations for those process segments
where TTO was regulated based upon the average percent removal of
TTO in the model technology. The average percent removal was
applied to the average concentration of TTO observed in the raw
wastewater of the respective process segment to determine a
treated effluent concentration.
Upon re-evaluating the raw waste data base in response to public
comments, EPA found that average concentrations of organics had
changed and that the TTO treated effluent concentrations
calculated based on applying a percent removal to average
concentrations were no longer valid. As previously described, a
review of available TTO treatability data for treatment systems
consisting of oil removal followed by chemical addition and
settling indicated that priority organics were treatable to
discrete treatment effectiveness concentrations that were
independent of influent concentration. This finding is in
keeping with the removal mechanism of organic priority
pollutants. Organic priority pollutants are much more soluble in
the oil and grease phase than the water phase of a wastewater
matrix. Effective removal of the oil and grease phase has been
shown to effectively remove organic priority pollutants. Data in
the metal molding and casting EPA and confirmed DMR data base
show that oil and grease can be treated to 5 mg/1 using
demonstrated techniques such as oil skimming and emulsion
breaking. Because the bulk parameter oil and grease can be
treated to a discrete limit (5 mg/1), and the mechanism for
organic priority pollutant removal is oil and grease removal, the
finding that priority organic pollutants are reduced to discrete
treatment effectiveness concentrations is as expected.
Therefore, these discrete treatment effectiveness concentrations
have been used to establish TTO treatment effectiveness
concentrations.
Treatment
Option 3 consists of Option 2 (recycle, lime and settle, plus oil
removal and chemical oxidation where necessary) with the addition
of filtration after the settling step. Treatment effectiveness
concentrations for Option 3 are presented in Table VII-14, The
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development of treatment effectiveness concentrations for Option
3 is described below.
Metals: Filtration is demonstrated in the metal molding and
casting industry. However, there are insufficient data from
which to develop lime and settle plus filtration treatment
effectiveness concentrations. EPA has identified three plants in
the metal molding and casting industry employing effluent
filtration for which treatment effectiveness data are available.
One filtration system is operated in conjunction with a
biological treatment system; filtered effluent from the
biological system is r .cycled back to the process operations, A
second filtration system is employed to treat the blowdown from a
recycle system employing settling only. The third treats the
effluent from a lime and settle system treating wastewater
discharged from a ferrous foundry on a once-through basis. None
of these systems is identical to the model technology that
describes technology Option 3-recycle, limn and settle, plus
filtration.
Concentrations of lead and zinc in the treated effluent from a
lime and settle plus filtration treatment system are based on the
long-term mean lime and settle treatment effectiveness
concentrations for the metal molding and casting industry,
reduced by one-third. The one-third reduction from lime and
settle values was based on an analysis performed on the CKDB lime
and settle data and on lime, settle, and filter data from plants
in several metals categories. In the analysis, lime and settle
effluent values were compared with lime, settle, and filter
effluent values to determine the percent reduction of metals
achieved by filtration. The analysis showed that, on average,
the effluent concentrations from filtration were approximately
one-third lower than those from the lime and settle systems
alone. This analysis is described in detail in Section VII of
the proposed development document for this rulemaking.
To determine whether this one-third reduction would also apply to
metal molding and casting wastewaters, the Agency compared the
lime and settle effluent data obtained from metal molding and
casting plants with the characteristics of the lime and settle
effluent used in the analysis. Table VII-15 presents such a
comparison. This table demonstrates that the lime and settle
zinc and lead effluent concentrations of metal molding and
casting and combined metals data base wastewaters are similar and
thus the one-third pollutant reduction determined for CMDB
wastewater may also be expected for zinc and lead in metal
molding and casting wastewater.
Results of an EPA pilot plant study at a ferrous plant (Tyler
Pipe Industries, Inc., Tyler, Texas) showed that filtration
reduced the concentrations of lead and zinc by about 67 percent
below that achieved by a lime and settle treatment system. These
pilot data support the achievability of the one-third reduction
in metals concentrations chosen for this regulation. However,
the metals and TSS concentrations from the lime and settle
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treatment system operated as part of the pilot unit were higher
than those that generally characterize the effluent
concentrations from lime and settle systems employed in the metal
molding and casting industry. Therefore, it is quite likely that
the pilot filters removed metals to a greater degree than if
lower concentrations of metals and TSS, such as those expected to
result from the use of well-operated lime and settle systems in
the metal molding and casting category, had been treated in the
pilot filtration unit. For this reason, rather than assuming
that 67 percent removal of metals will occur after the
application of filtration technology as demonstrated on the pilot
level, the Agency based lime, settle, and filter treatment
effectiveness concentrations on a 33 percent removal of lead and
zinc, as has been demonstrated at three full scale treatment
systems in other, similar industries.
The one-third reduction does not apply to copper. Further
reduction of the long-term treated effluent copper concentrations
below the lime and settle treatment effectiveness concentrations
of 0.065 mg/1 (ferrous subcategory) and 0.17 rag/1 (nonferrous
subcategories) using filters has not been demonstrated by data
available from other industries. Therefore, the long-term
treated effluent copper concentrations for ferrous and nonferrous
wastewater treated by lime, settle, and filtration is being
maintained equal to the lime and settle treatment effectiveness
concentrations.
The maximum monthly and maximum day effluent limitations for
filtration are based on the same variability factors developed
for lime and settle treatment. However, the performance of
filtration is expected to reduce the treated effluent variability
from that demonstrated by lime and settle treatment. This is
expected because of the observation that increases in TSS
concentrations in the influent to filters do not affect
significantly the treated effluent concentrations expected. In
the event of markedly higher influent TSS concentrations for
extended periods of time, the duration of the filter operation
cycle decreases because solids build up more rapidly than at
lower influent concentrations, thus requiring more frequent
backwashing. However, treated effluent concentrations remain
approximately the same as long as the normal range of pressure
drop across the filter is observed in order to prevent washout
("breakthrough") of previously filtered solids into the effluent
stream. Therefore, even though more stable (i.e., lower
variability) effluent quality is expected from filters, the
Agency has chosen the more conservative and numerically higher
variability factors used for lime and settle as the basis for
variability of lirae, settle, and filter treated effluent
concentrations.
TSS, Oil and Grease, Total Phenol; The long-term average treated
effluent concentration for TSS is 2.6 mg/1. This concentration
is based on data from several metals industry plants presented in
Table VII-16. The 10-day average concentration calculated based
on this data is 4.33 rag/1, the 30-day average is 3.36 mg/1, and
368
-------
the one-day maximum is 8.88 mg/1. These calculated values more
then amply support the classic 30-day and one-day values of 10
mg/1 and 15 mg/1, respectively, which are used for LS&F. Some
incidental removal of oil and grease, total phenol, and toxic
organics may be achieved in a filtration system. However,
significant reductions in treated effluent concentrations below
those achieved by lime and settle is not expected. Therefore, no
further reductions in oil and grease, and total phenol beyond
those achieved by lime and settle are being assumed for
filtration.
Treatment Option 4_
In treatment Option 4, the effluent from the Option 3 treatment
train is treated with activated carbon. Effluent concentrations
for this option were calculated for purposes of cost and benefit
analyses. However, Option 4 was not selected as the technology
basis for any of the limitations being promulgated for the metal
molding and casting category. As a result, specific limitations
values such as the one-day maximum were not calculated for this
option.
Activated carbon treated effluent concentrations were assumed to
be equal to 0.01 mg/1 for all toxic organic pollutants. This
value was chosen for two reasons. First, the standard detection
limit for organic pollutants in a wastewater matrix is 0.01 rag/1.
Although activated carbon is capable of removing organics to
levels below 0.01 mg/1, routine detection of organics below this
level requires more sophisticated and costly analyses than those
assumed during calculation of monitoring costs for the metal
molding and casting category.
Second, it has been well-demonstrated under laboratory conditions
and well-documented in the scientific literature that activated
carbon treatment is capable of removing virtually all of the
toxic organic pollutants to levels below the normal detection
limits for those pollutants. However, large volumes of activated
carbon are required in relation to the wastewater volume. The
model treatment technology chosen as a basis for Option 4
includes one activated carbon column sized for the particular
plant flow, which is sufficient for removal of organics to 0.01
mg/1. Removal of toxic organics below this level would require
more than one carbon column in series, but multiple carbon
columns were not included as part of the model treatment
technology for Option 4.
Incidental removals of total phenol and oil and grease would be
expected to occur during activated carbon treatment but these
incidental removals are difficult to quantify in the absence of
analytical data. Thus, the Agency assumed that no further
reduction of metals, total phenol, or oil and grease will occur
at Option 4, and that Option 4 concentrations for those
pollutants are equal to those determined at Option 3.
369
-------
Table VII-1
TREATMENT TECHNOLOGY DEMONSTRATION STATUS
(Number of Plants in Metal Molding and Casting Data Base)
SubcategQp v
AiuninuiB
Copper
Ferrous
Magnesium
Zinc
TOTALS
Chemical
Addition
(Alfcsiin* Pr Acid)
H-Alkaline
5-Aeid
7-Allcallne
2-Acid
34-Alklaine
6-Acid
0
8-AJkaline
2-Acid
53-Alkaline
15-Acid
Fil tration
(Unspecified
or Pressure)
3-Unapecif led
5-Presaure
it-Unspecified
10-Un»pecif led
?-Pressure
0
1-Unspeoif ied
2-Pressure
18-Unapecified
It-Preasure
Settling
19
11
13«
0
12
179
S^iujjl f|g
21
1
28
0
8
61
Vacuum
£11 teat ion
1
«*
15
0
2
22
Other f SflPcJfy'
2-Activated Carbon
1-Ultrafiltration
1-Activated Carbon
3-Activated Cerbon
1-UltrafUtration
-------
Table VII-2
CLASSES OF ORGANIC COMPOUNDS ADSORBED ON CARBON
Chemical Class
Aromatic Hydrocarbons
Polynuclear Aromatics
Chlorinated Aromatics
Phenolics
Chlorinated Phenolics
High Hoi cular Weight Aliphatic
and Bra .ch Chain Hydrocarbons
Chlor aated Aliphatic Hydro-
carb,' s
High
Aci
-ular Weight Alipha
Aromatic Ac'1 •
High Molecular Weight -. ; -M
Amines and Aromatic JL,;;.
High Molecular Weight .....
Esters, Ethers and Alconc -
Surfactants
Soluble Organic Dyes
Examples of Chem4
-------
Table VII-3
THEORETICAL SOLUBILITIES OF HYDROXIDES, CARBONATES,
AND SULFIDES OF SELECTED METALS IN PURE WATER
Solubility of Metal Ion (mg/1)
Cadmium (Cd++)
Chromium (Cr+++)
Cobalt (Co+4-)
Copper (Cu++)
Iron (Fe++)
Lead (Pb++)
Manganese (Mn++)
Mercury (Hg++)
Nickel (Ni-nO
Silver (Ag+)
Tin (Sn++)
Zinc (Zn++)
As Hydroxide
2.3 x 10~5
8.4 x 10
2.2 x 10
-4
-1
-2
2.2 x 10
8.9 x 10"1
2,1
1.2
3.9 x 10~4
6.9 x 1Q~3
13.3
1.1 x 10~4
1.1
As Carbonate
1.0 x 1Q~4
7.0 x 10
-3
3.9 x 10
1.9 x 10
2,1 x 10
-2
-1
7.0 x 10
-4
As Sulfide
6.7 x 10
-10
No precipitate
1.0 x 10~8
5.8 x 10
-18
-5
3.4 x 10
3.8 x 10~9
2.1 x 10~3
9.0 x 10
6.9 x 10
7.4 x 10
3.8 x 10
2.3 x 10
-20
-8
-12
-8
-7
372
-------
Table VII-4
RECYCLE DEMONSTRATION STATUS
Aluminum
Copper
Ferrous
Segment
Casting Cleaning
Casting Quench
Die Casting
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Helting Furnace Scrubber
Hold Cooling
Casting Quench
Direct Chill Casting
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace Scrubber
Hold Cooling
Casting Cleaning
Casting Quench
Level of Demonstrated Recycle
2 of 3 processes that recycle achieve
at least 95? recycle (all subcatego-
ries)
8 of 14 processes that recycle
achieve at least 985 recycle
T of 11 processes that recycle achieve
at least 955 recycle Call nonferrous)
7 of 11 processes that recycle achieve
at least 98J recycle (all nonferrous)
2 of 3 processes that recycle achieve
100? recycle (all nonferrous)
No recyclers identified
5 of 13 processes that recycle achieve
at least 96f recycle (all nonferrous)
15 of 25 processes that recycle
achieve at least 95? recycle (all
subcategories)
4 of 7 processes that recycle achieve
at least 98$ recycle
5 of 7 processes that recycle achieve
at least 95? recycle
7 of 11 processes that recycle achieve
at least 98$ recycle (all nonferrous}
2 of 3 processes that recycle achieve
1005 recycle (all nonferrous)
No recyclers identified
5 of 13 processes that recycle achieve
at least 96| recycle (all nonferrouc;
15 of 25 processes that recycle
achieve at least 95J recycle (all
subcategories)
2 of 3 processes that recycle achieve
at least 95J recycle (mil
subcategoriea)
17 of 24 processes that recycle
achieve at least 98$ recycle
373
-------
Table VII-4 (Continued)
RECYCLE DEMONSTRATION STATUS
Subcategorv
Ferrous
(Cont.)
Magnesium
Zinc
Segment
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace Scrubber
Hold Cooling
Slag Quench
Wet Sand Reclamation
Casting Quench
Dust Collection Scrubber
Grinding Scrubber
Casting Quench
Die Casting
Melting Furnace Scrubber
Mold Cooling
Level af Demonstrated Recycle
77 of 126 processes that recycle
achieve at least 985 recycle
5 of 1} processes that recycle achieve
100$ recycle
Mo recyclers identified
47 of 85 processes that recycle
achieve at least 98J recycle
15 of 25 processes that recycle
achieve at least 95J recycle (all
subcategories)
28 of 52 processes that recycle
achieve at least 955 recycle
3 of 6 processes that recycle achieve
at least 80J recycle
If of 30 processes that recycle
achieve at least 985 recycle (all
nonferrousS
7 of 11 processes that recycle achieve
at least 985 recycle (all nonferrous)
2 of 3 processes that recycle achieve
100J recycle (all nonferrous)
14 of 30 processes that recycle
achieve at least 98$ recycle (all
nonferrous)
7 of 1t processes that recycle achieve
at least 955 recycle (all nonferrous}
4 of 7 processes that recycle achieve
at least 96J recycle
15 of 25 processes that recycle
achieve at least 955 recycle Call
subcategorias)
374
-------
Table VII-5
METAL MOLDING AND CASTING LIME AND SETTLE TREATMENT
EFFECTIVENESS CONCENTRATIONS (mg/1)
EPA AND CONFIRMED DMR DATA
Pollutant
Copper
Lead
Zinc
Oil and Grease
Phenols
Total Suspended Solids
Ferrous Plants
One-Day
Maximum
1
38
1
38
0.23
0.93
47
1
10-Day
Monthly
Maximum
0,
0,
0,
12
0,
15
13
43
56
36
Long-Term
Average
0.062
0.23
0.40
6
0.23
10
Nonferrous Plants
Copper
Lead
Zinc
Oil and Grease
Phenols
Copper
Lead
Zinc
Oil and Grease
Phenols
Solids
Ferrous and
Solids
0.62
0.24
0.46
11
0.29
23
Nonferrous
0.29
0.79
1.14
30
0.86
33
0.32
0.20
0.16
5
0.15
8.4
Plants
0.16
0.39
0.43
10
0.30
13
0.087
0.19
0.069
3
0,13
5.3
0.065
0.22
0.2?
5
0.20
8.6
375
-------
Table VII-6
METAL HOLDING AND CASTING LIME AND SETTLE TREATED
EFFLUENT CONCENTRATIONS (rag/1)
INDIVIDUAL PLANT DATA FOR COPPER
Ferrous Plants
Tyler Pipe (South)
Tyler, TX
Griffin Pipe
Florence, NJ
J.I. Case
Racine, WI
Chrysler
Indianopolis, IN
Deere
Waterloo, IA
Long-Term
Mean
0.077
0.042
ND
0.31
ND
One-Day
Variability
Factor
1.87
5.94
2.46
10-Day
Variability
Factor
1.00
2.75
1.16
NL Industries
Pottstown, PA
Olin
East Alton, IL
Nonferrous Plants
ND
0.17
4.45
1.70
ND - Not detected.
376
-------
Table VII-7
METAL MOLDING AND CASTING LIME AND SETTLE TREATED
EFFLUENT CONCENTRATIONS tfflg/1)
INDIVIDUAL PLANT DATA FOR LEAD
Ferrous Plants
Tyler Pipe (South)
Tyler, TX
Tyler Pipe
Macungie, PA
Griffin Pipe
Florence, NJ
Tyler Pipe (North)
Tyler, TX
J.I. Case
Racine, WI
Chrysler
Indianopolis, IN
Deere
Waterloo, IA
Long-Term
Mean
0.50
0.20
ND
0.56
ND
One-Day
Variability
__ Fac.tor__
2.83
2.88
0.37
0.62
4.53
3.06
2.79
10-Day
Variability
Factor
1.20
1.75
1.32
1.21
1.20
NL Industries
Pottstown, PA
Nonferrous Plants
0.19 1.28
1.00
ND - Not detected.
377
-------
Table VII-8
METAL HOLDING AND CASTING LIME AND SETTLE TREATED
EFFLUENT CONCENTRATIONS (mg/1)
INDIVIDUAL PLANT DATA FOR ZINC
Ferrous Plants
One-Day
10-Day
Plant
Tyler Pipe (South)
Tyler, TX
Tyler Pipe
Macungie, PA
Griffin Pipe
Florence, NJ
Tyler Pipe (North)
Tyler, TX
J.I. Case
Racine, WI
Chrysler
Indianapolis, IN
Deere
Waterloo, IA
NL Industries
Pottstown, PA
Olin
East Alton, IL
Long-Term
Mean
0,
0.
0.
0.
0.
1.
0.
92
41
48
73
13
09
08
Nonf errous
0.
0.
03
12
Variability
Factor
4.
3.
3.
3.
2.
5.
2.
Plants
16.
3.
46
81
74
38
05 .
29
94
18
87
Variability
J^ctor
1
1
1
1
1
1
1
4
1
.34
.27
.29
.25
.15
.40
.25
,00
.33
378
-------
Table VII-9
METAL MOLDING AND CASTING LIME AND SETTLE TREATED
EFFLUENT CONCENTRATIONS (mg/1)
INDIVIDUAL PLANT DATA FOR OIL AND GREASE
Ferrous Plants
One-Day
10-Day
Plant
Tyler Pipe (South)
Tyler, TX
Tyler Pipe
Macungie, PA
Griffin Pipe
Florence, NJ
Tyler Pipe (North)
Tyler, TX
J.I. Case
Racine, WI
Chrysler
Indianapolis, IN
Deere
Waterloo, IA
NL Industries
Pottstown, PA
Olin
East Alton, IL
Long-Term
Re an
4.8
10
2.4
5.1
7.1
2.1
18
Nonf errous
6.8
0,9
Variability
Factor
7.
12.
4.
6,
9.
3.
3.
Plants
3.
5.
39
65
17
18
27
10
31
67
78
Variability
Factor
1.72
2.22
2.86
1.53
1.72
1 .22
1.24
1.27
2.64
379
-------
Table VII-10
METAL HOLDING AND CASTING LIME AND SETTLE TREATED
EFFLUENT CONCENTRATIONS (mg/1)
INDIVIDUAL PLANT DATA FOR PHENOL
Ferrous Plants
Plant
Tyler Pipe (South)
Tyler, TX
Griffin Pipe
Florence, NJ
J.I. Case
Racine, VI
Chrysler
Indianapolis, IN
Long-term
Mean
0.82
0.052
0.017
3.95
One-Day
Variability
Factor
1.87
10.24
1,94
2.67
10-Day
Variability
Factor
1.11
1.80
1.00
1.18
NL Industries
Pottstown, PA
Nonferrous Plants
0.13 2.33
1.15
380
-------
Table VII-11
METAL HOLDING AND CASTING LIME AND SETTLE TREATED
EFFLUENT CONCENTRATIONS (mg/1)
INDIVIDUAL PLANT DATA FOR TOTAL SUSPENDED SOLIDS
Ferrous Plants
One-Day
10-Day
Plant
Tyler Pipe (South)
Tyler, TX
Tyler Pipe
Macungie, PA
Griffin Pipe
Florence, NJ
Tyler Pipe (North)
Tyler, TX
J.I. Case
Racine, WI
Deere
Waterloo, IA
NL Industries
Pottstown, PA
Olin
East Alton, IL
Long-Term
_ Mean
9.9
9.8
13
10
4.1
20
Nonferrous
7.5
3.8
Variability
Factor
3.17
5.56
4.72
3-09
2.17
3.71
Plants
3.70
5.07
Variability
Factor
1.23
1.44
1.35
1.22
1.14
1.59
1.40
1.38
381
-------
Table VII-12
TREATMENT EFFECTIVENESS CONCENTRATIONS FOR THE
METAL MOLDING AND CASTING
CATEGORY - OPTION 2
F-SJT-PUS 3j-JbQafre£gr¥
-Eii^l-UQjit J^pj]cej'it;r_afrj-O?7s (rqg/j,)
Ten-Dav Average Qne-Dav Maximum
Copper 0.065 0.16 0.29
Lead 0.22 0.39 0.79
Zinc 0.40 0.56 1.47
TSS 10 15 38
O&G 5 10 30
Phenol 0.20 0.30 0.86
Effluent Concentrations
Lcmg-Term Ten-Dav Average QnB-Qay Maximum
Copper 0.17 0.42 0.77
Lead 0.22 0.39 0.79
Zinc 0.27 0.43 1.14
TSS 10 15 38
O&G 5 10 30
Phenol 0.20 0.30 0.86
382
-------
Table VII-13
TREATMENT EFFECTIVENESS CONCENTRATIONS FOR
PRIORITY TOXIC ORGANIC POLLUTANTS (mg/1)
Pollutant;
1. acenaphthene
4. benzene
5. benzidine
6, carbon tetrachloride
7. chlorobenzene
10. 1,2-dichloroethane
11. 1,1,1-trichloroethane
14. 1,1,2-trichloroethane
21. 2,4,6-trichlorophenol
22. p-chloro-m-cresol
23. chloroform
24. 2-chlorophenol
30. 1,2-traps-dlchloroethvlene
31. 2,4-dichlorophenol
34. 2,4-dimethylphenol
38. ethylbenzene
39. fluoranthene
43. bis(2-chloroethoxyJmethane
44. methylene chloride
45. methyl chloride
48. dichlorobromomethane
54. isophorone
55. naphthalene
57. 2-nitrophenol
53. 4-nltrophenol
59. 2,4-dinitrophenol
60. 4,6-dinitro-o-cresol
62. N-nitrosodiphenylamine
63. N-nitrosodi-n-propylamlne
64. pentachlorophenol
65. phenol
66. bis(2-ethylhexyl) phthalate
67. butyl benzyl phthalate
68. di-n-butyl phthalate
69. dl-n-octyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
72. benzo(a)anthracene
Long-Term Average
Treatment Effectiveness
Concentration^ (mg/1)
0.010
0.020
0.022
0.020
0.020
0.022
0.020
0.022
0.048
0.022
0.078
0.022
0.022
0.048
0.010
0.020
0.018
0.024
0.059
0.024
0.016
0.016
0.024
0.022
0.022
0.010
0.010
0.010
0.010
0.014
0.018
0.032
0.010
0.022
0.022
0.016
0.013
0.010
383
-------
Table VII-13 (Continued)
TREATMENT EFFECTIVENESS CONCENTRATIONS FOR
PRIORITY TOXIC ORGANIC POLLUTANTS (mg/1)
Long-Term Average
Treatment Effectiveness
Pollutant
73. benzo(a)pyren-., 0.010
74. 3,4-benzofluoranthene 0.011
75. benzo(k)fluoranthene 0,014
76. chrysene 0,014
77. acenaphthylene 0,014
78/81. antnracene/phenanthrene* 0.010
80, fluorene 0.010
84. pyrene 0.012
85. tetrachloroethylene 0.047
86. toluene 0.020
87. trichloroethylene 0.020
•These two compounds are generally reported together,
384
-------
Table VII-14
TREATMENT EFFECTIVENESS CONCENTRATIONS FOR THE
METAL MOLDING AND CASTING CATEGORY
OPTION 3
teoc
Long-Term
Effluent
Concentration
Pollutant
Copper
Lead
Zinc
TSS
O&G
Phenol
0.065
0.15
0.26
2.6
5
0.20
10-Day
Average
Effluent
Concentration
fm/1)
0
0
0
12
10
0.30
16
26
37
One-Day
Maximum
Effluent
Concentration
fme/11
0
0
0
15
30
0
29
53
98
86
Nonferrous
Pollutant
Copper
Lead
Zinc
TSS
O&G
Phenol
Long-Term
Effluent
Concentration
fm/1)
0
0
0
2
5
0.20
17
15
18
6
10-Day
Average
Effluent
Concentration
Caig/1)
0.42
0.26
0.29
12
10
0.30
One-Day
Maximum
Effluent
Concentration
(mg/1)
0.77
0.53
0.76
15
30
0.86
Note: TSS concentrations for Option 2 are presented in Table
VII-13, Filtration is not expected to reduce TTO
concentrations significantly.
385
-------
Table VII-15
LIME AND SETTLE EFFLUENT DATA
COMPARISON BETWEEN THE COMBINED METALS DATA BASE
AND METAL MOLDING AND CASTING DATA
Lime and Settle Lime, Settle and Filter
Effluent fmg/1) Effluent (me/1)
MM&C
Cu
Pb
Zn
CMOS
0.58
0.12
0.33
Fer rails
0.065
0.22
0.40
Nonferrous
0.17
0.22
0.27
CMDB
0,39
0.08
0,23
MM&C
Ferrous
0.065
0.15
0.26
Monf erroua
0.17
0.15
0.18
All data are long-term averages.
366
-------
Plant
Mmber
06097
13924
18538
30172
36048
Mean
Table VII-16
MULTIMEDIA FILTEH PERFOiMANCE
TSS fiffluent; Concentration, tqg/I
0.0, 0.-0, 0.5
1.8, 2.2, 5.6, 4.0, 4.0, 3.0, 2.2, 2.8, 3.0,
2.0, 5.6, 3.6, 2.4, 3.4
1.0
1.4, 7.0, 1.0
2.1, 2.6, 1.5
2.61
387
-------
rLANOE
wjurri WAT!*
•ASM WATCH
•UHFACt WA«H
MANIFOLD
•ACXW
•ACKWASH
HfPt.A6tMCNT CAM BON
CARSON MCMOVAL POUT
THXATCO WATER
•UWOUT PtATK
Figure VII-1
ACTIVATE ' ;:
-------
0.40
0.30
a
3
0 0.20
y
j
0,10
CAUSTIC SODA.
0.0
9.5
SODA ASH AND
CAUSTIC SODA
10.Q
10.!
Figure VII-2
LEAD SOLUBILITY IN THREE ALKALIES
389
-------
INFLUENT
IFFLUCNTlK
COULlCTtON CHAMBER
OltAtN
Figure VII-3
BED FILTBATION
390
-------
a* c KIN a
MCOtUM
tot. to
HI6TAN9UI.AH
I NO Pl»ATt,
IHLIT
fLUOOK
MCD1UM
CNTKAWKQ tOUDf
PLATCIAND fWAMIf AAt
TOOCTHtR DURING
HCCTANOULAII
METAL
Figure V1I-4
PRESSURE FILTHATION
391
-------
SEDIMENTATION BASIN
INLET ZONE
BAFFLES TO MAINTAIN
auiHCENT CONDITION*
OUTLET ZONE
INLET LIQUID
"•••i^. SETTLING PARTlCLf
* ' • """**-»!• TRAJECTORY . «
. • . • • ^^•_L « " I «
/ •^"—-L. * * 4 * .
• • , • •*• *^«». *t * *.
> *
«* •
OUT LIT LIQUID
• ELT-TY« SOLIDS COLLrCTtOH
MECHANISM
SETTLED PARTICLES COLLECTED
AND PERIODICALLY REMOVED
CIRCULAR CLARtriKR
INLET LIQUID
CIRCULAR BAFFLE
SETTLING ZONE
ANNULAR OVERFLOW WEIR
OUTLET LIQUID
REVOLVING COLLECTION
MECHANISM
I
SETTLING PARTICLES
SETTLED PARTICLE*
COLLECTED AND PERIODICALLY
HCMOVED
SLUOQX ORAWOFF
Figure VII-5
REPRESENTATIVE TYPES OF SEDIMENTATION
392
-------
SEPARATOR CHANNEL
GATEWAY PIER
SLOT FOR
CHANNEL GATE
FOREBAY
SLUDGE COLLECTING
HOPPER
DIFFUSION DEVICE
(VERTICAL-SLOT BAFFLE)
FLIGHT SCRAPER
CHAIN SPROCKET
ROTATABLE OH
SKIMMING PIPE
FLIGHT SCRAPER
CHAIN
WATER
LEVEL
WOOD FLIGHTS
I t i
FLOW
OIL RETENTION
BAFFLE
SLUDGE - COLLECTING HOPPER
DISCHARGE WITH LEAD PiPE.
SLUDGE PUMP*
SUCTION PIPE
>-EFFLUENT
WEIR AND
WALL
EFFLUENT
SEWER
EFFLUENT FLUME
Figure VII-6
GRAVITY OIL/WATER SEPARATOR
-------
PABHIC on wtni
riLTBA MIDI*
rrntTCNia oven
REVOLVING BRUM
ROU.1H
SOUBSICftAPCfi
OFF riLTKR MEDIA
BIMCCTION OF ROTATION
•OLIO* COLLECTION
MOPPtR
tNLIT LIQUIO
TO BC
FILTER EO
-TKOUOM
LIQUID
Figure VII-7
VACUUM FILTRATION
394
-------
LIQUID
OUTLET
SLUDGE
JNLCT
rU\J\JVM\JVIV.
M M M M
CONVCYOR »OWL RCCULATING IMPtLLER
CYCLOGEAR
Figure VII-8
CENTRIFUGATION
395
-------
OILY WATIR
INFLUENT
WATES
DISCHARGE
OVERFLOW
SHUTQFF
VALVE
EXCESS
AIR OUT
LEVEL
CONTROLLER
TO SLUDGE
TANK "•
Figure VII-9
DISSOLVED AIR FLOTATION
396
-------
CONDUIT
TO MOTOR
INFLUENT
CONDUIT TO
OVfRLOAO
ALARM
EFFLUENT
EFFLUENT CHANNEL.
PLAN
TU*NTA»WI
•ASK
HANDRAIL
DRIVE
L
WltM
(NfLUtNT
CENTER COLUMN
— CENTER CAGE
Figure VII-10
GRAVITY THICKENING
397
-------
c
A
I
T n
TT
||
ti
1 n i
ii
I*
il
j!
1 n
ii
Jl
«-m. viTJtirr
WITH PLASTt
3 ii <
i]
t!
If
H
fi
^-SPLASH SOX
X-lU F"
I 1 1
t<» 1
_^H-_|
o
5
t
c
1
o
ft
1
1 t
ii
(!
1
(1
3 H (
It
JL._.
5 P1PC LAID — ^
JOINTS
; n J
r ff 1
tt
ti
ij
|!
H
t it k
ti
fi
11
r " !! i
sin
- it'
* £1'
> 0||
J ZH! C
• >|f
J^
^
r !i l
,i
j
M
U
i it q
«-IN. FLANGE
X^~SHCA»» GATE
\ \\
V— ^
B
= ^i^-— rt.
r
li
i Jt c
(1
1!
,
M
M
i H I
II
™JL
""if
ii l
it
il
M
I
° il
1 h
-=urddj
A
t
«-IN. CI PIPC
PLAN
••IN,
SAND
SANQ
J-IN. F1NC G«AVIU
}-IN, MKOtUM GKAVXL
1 TO * IN. CQAJMC CftAVCL
\-
Z»m, PLAHK
WALK
COUUMN POM
J.fN. MEDIUM GRAVEL
fl-tN. UNOCROP?AIN LAiO-
WtTH OPCN JOINTS
SECTION A*A
Figure VII-I1
SLUDGE DRYING BED
398
-------
VLTMAFILTMATION
MACftOMOUKCULIB
WATIft SALT!
KRMKATC
* *
-MEMBMANC
* *
FEED
• •
• » •
• * • * .. O CONCENTRATE
• „ • o • * *o « «
0 - - • o o • o Q
* I *
*
1 *
0 OIL PAMTICLC*
* DtClOLVKD *AUTI AND LOW-MOLKCUUAM-WCtaHT OKGANICC
Figure VII-12
SIMPLIFIED ULTRAFILTRATION FLOW SCHEMATIC
399
-------
B,U
Matte -up •
O
o
PROCESS
TREATMENT
i
GQC,
(Pot iutanu
Q
A
Bf
il.,
G
i»
C -
- Total Flow
- Btoiudown Fr action
-Evaporative Loss Kraclton from the Process
- twupanjuve J ass Fraction tfoin ibe Ifealmadl
-FiacltCMi of Fiowraie Loss Due Jo Potlufont Removoi
-Amount at Poll ul an I Added Each Pass
- Concenlraljon o{ Maltna) ofler "N" Cycles
-Concentiutton uf Maitftai ftemaved by the Treatment System
Conceixt*atian o! Material in I fie Make-up Wolar
ConCKiitfdliOH ot Mulertal Disctiarged aiitt to KcLytle i uup
= Coucenlialion (»( Mutertal ot 1 > t f'Oabtib iiuoiKjh iha
Figure VII-13
WATER CHEMISTRY MODEL ~ GENERALIZED WASTEWATER RECYCLE SYSTEM
-------
Recycle to |
Process Cooling 1
" , {if required) J'
.. _ J
Fran HM&C
Process
P«
Adjustment
j
!_
Settling
Device
(oil skiounlng
If required)
Acid or
Caustic
< •• — Oil to Contractor
Removal Cooling towers
f Cu CQ
i Cu DCC
— — ~ ~ — —*> Cu ^
i r ff en
F* HC
Settling Discharge 2n MC
Slowdown ^ Device - fc K
{oil gkintning
_^ if required) Vacuum filters
Filtrate 1 L, A Cu DCC
(Sludge Cu MC
1 _. — Jf _ _ ( Fe MS8
— _|
Vacuum
required in:
10-49, 50-99, 100-249, 5250
all
all
50-99, 100 249 *250
all
all
required in:
a2SC)
100-249
*250
squired Int
Sludge
J (If required)*
Sludge to Contractor
Removal
Al - CQ, CS, 1C, MFS, HC
Cu - CQ, DCC, UC, CS, 1C, MFS, HC
fe - CQ, UC. 1C, MFS, MC
Hg - CQ, UC, S3
Zn - CQ, MFS, ML
Figure VII-14
TREATMENT OPTION 1; RECYCLE AND SETTLE
-------
Recycle to
Process
•«*—
I Cooling To"*r *
Cif r«jylr«4) j
Sludge
Oil to Centra
h
*
I
Settling Devic<
(oil ni li»lrifl
If required)
VBCUIH i
niter
• (If retired) I
I
Discharge
Cooling tMMT* requited In;
Cu CQ 1O-49, 50-99, 100-249, 2250
Cm »CC all
Cu 1C all
r« OQ 50-99, 100-249, S250
f« NC all
In HC »U
Vacuum filtcca required in:
Cu DCC S230
Cu HC 100-249
F« MS* SZ3Q
Oil sktHdng required In:
Al - OQ. CS, 1C, MfS, HC
Cu - QJ, OCC, UC, CS, 1C, MFS, MC
F« - OQ, UC, 1C, NFS, MC
1% - OQ, UC, GS
Za - OQ, NFS, ML
oxidation required in:
Al - UC, MFS
Cu - K, MFS
F« - UC» MFS, HSK
Zn - MFS
Sludge to Contractor
il
Figure VII-15
TREATMENT OPTION 2: RECYCLE, LIME, AND SETTLE
-------
JAcld
Recycle to
Process
Polymer
Lime
1.JTIHCL , ,
i 1 1
KHnO,
PH
Adjustment
From Die Casting
Process
Emulsion
Breaking/
Oil Skimming
I
Chemical
Addition
Settling
Device
Discharge
J
Oil to Contractor
Removal
Sludge to Contractor
Removal
Figure VII-16
TREATMENT OPTION 2 FOR ALUMINUM AND ZINC DIE CASTING PROCESS
-------
o
>u
Pruc.-ss
Pro* HH&C
Process
Caul I ng, TBve r
(if required)
PH
s*
I01J
Set tiling Device
(oil gfclaving
If required)
Sludge
i
1
Oil to Contractor
Acid or *
Caustic 1
-^ i
s- 1
s- „ , KHnO^ 1
1|(lf required) ( Baekl,aah
i i 4 I
Settling Devlc< Diacharae
Blowdnvn ^ Chentcal ^ (oil «H~,-inj. ^ Plltmtlan ^
Addition tf required)
r "*
{Sludge
,_ J--1--,
Vacuum
" (if required) 1
^ _ T . _J
I
Cooliuy towec« required inr
Cu CQ 10-49, 50-99, 100-249, 5250
Cu DCC all
Cu HC all
Fe O} 50-99, 100-249, ^50
Ye HC alt
Zn HC all
filters required In:
Cu DCC S250
Cu MC 100-249
Fe HSR 1250
Oil skimming required In:
Al - OJ, CS, 1C, MFS, HC
Cu - CQ, DCC, UC, CS. 1C, UTS, MC
Fe - CQ, OC, 1C, MTS, HC
Ng - oj, uc. cs
En - OQ, HFS, ML
?InO> oxidation required Iru
Ai - UC, HFS
cu - uc, firs
fe - UC, HTS, USR
Zn - HFS
Sludge to Gnntractor
Kein^va 1
Figure VII-17
TREATMENT OPTION 3: RECYCLE, LIME, SETTLE, AND FILTER
-------
Fron Die Casting
Process
Oil to Contractor
Removal
Sludge to Contractor
Removal
Figure VII-18
TREATMENT OPTION 3 FOR ALUMINUM AND ZINC DIE CASTING PROCESS SEGMENTS
-------
Recycle to
Process
From HH4C
Process
i
*• .
O
0V
1
Coullng Tower *
(11 required) |
J Oil to Contractor
tRet.ji.-nl
Acid or *
PH
t
Joti
Settling Oewice
Caustic 1
x- I
S IMnOi '
^-4 11 t * I
let t ling Devic«
BloMslown fc Che»ic«i fni i ^(,,,{^0 fc Filtration
" Addition ' if required) ""
r •*
[sludge
1_ _| t
V«£OUX I
Csrton Discharge
felBof|»i:ieii
siud(J
-------
Fro* Die Casting
Process
Oil to Contractor
Renoval
Sludge to Contractor
Removal
Figure VI1-20
TREATMENT OPTION 4 FOR ALUMINUM AND ZINC DIE CASTING PROCESS SEGMENTS
-------
Recycle to
Process
pH Adjustment
From MM&C
Process
Acid
Settling Device
with
Oil Skimming
!0il to Contractor
* Removal
Sludge to Contractor
Removal
Figure VII-21
TREATMENT OPTION 5: SETTLE AND COMPLETE RECYCLE
408
-------
SECTION VIII
COST, ENERGY, AND NON-WATER QUALITY IMPACTS
This section
and control
estimates,
performance
Section IX,
presents estimated costs of the wastewater treatment
technologies described in Section VII. These cost
together with the estimated pollutant reduction
for each treatment and control option presented in
provide a basis to evaluate the treatment and control
options and to identify the best practicable control
the best available
the best conventional
technology
technology currently available (BPT)
technology economically achievable (BAT)
pollutant control technology (BCT),
demonstrated technology (BDT), and the
for pretreatment standards (PSES/PSNS),
also used as the basis to estimate
the best available
appropriate technologies
The cost estimates are
the economic impact of
compliance with the final effluent limitations guidelines and
standards on the metal molding and casting category. In
addition, this section addresses nonwater quality environmental
impacts of the wastewater treatment and control options,
including energy requirements and air pollution and solid waste
generation.
COST ESTIMATION
Industry-wide compliance costs have been developed for each of
the five technology options considered for the metal molding and
casting category. In summary, the five technology options
considered are:
Option 1 - High rate recycle,
Option 2 - High rate recycle,
Option 3 - High rate recycle,
filtration
Option 4 - High rate recycle, chemical addition, settling,
filtration, activated carbon adsorption
Option 5 - Complete recycle.
Compliance costs for each option were calculated using a model
plant approach. A model plant has been developed for each of
many divisions of the category, as divided by metal type,
employment size group, and process type. To calculate the
industry cost for a particular treatment option, the following
procedure was carried out. The model plant costs were multiplied
by a utilization factor, which accounts for treatment-in-place.
These values were then multiplied by the number of dischargers
within the industry within the particular segment. The three
inputs used to calculate industry costs, (1) model plant costs,
(2) utilization factors, and (3) projected number of dischargers,
are described in greater detail in the material that follows.
settling
chemical
chemical
addition,
addition,
settling
settling,
409
-------
Model Plant Costs
A sample model plant coat sheet is presented for discussion
purposes as Table VIII-1.
All model plant costs are expressed in terms of first quarter
1983 dollars. The sample model plant cost sheet presented in
Table VIII-1 is for the ferrous gubcategory, dust collection
scrubber wastewater control, for a plant with 10-49 employees
engaged in metal molding and casting activities. A model plant
within this segment operates one shift per day (the mean of all
survey data for the segment, rounded to the nearest whole number
of shifts).
The model plant for this segment has a scrubber air flow of
28,400 scfm (the mean of all survey data for a plant with 10-49
employees in this process segment). Water use is related to air
flow in scrubber operations (dust collection scrubber, grinding
scrubber, melting furnace scrubber), tons of sand reclaimed in
wet sand reclamation, and tons of metal poured for all other
metal molding and casting operations. The relationship of water
used to these parameters is documented in Section IV.
The header line on the sample model plant cost sheet labeled
"Treatment Component" lists the equipment required for Treatment
Option 3. Option 3 for this segment consists of settling in a
drag tank, followed by recycle to the process with acid addition
to control scale formation. The blowdown from the recycle loop
is treated with chemicals in a batch tank to enhance pollutant
removals. Chemical treatment for ferrous dust collection waste
water includes potassium permanganate addition to oxidize phenol
ics and other organics and lime and polymer addition to enhance
solids settling and metals removals. After chemical addition and
mixing in the batch tank, the wastewater is allowed to settle for
four hours, and is then passed through a cartridge filter prior
to discharge. All treatment options considered for this and
other process segments are described in Section VII. Costs for
individual components of the treatment system are estimated based
upon data in Section 22.43 of the record. A list of the
treatment component abbreviations used on the model plant cost
sheets is provided along with those sheets in Section 22.43 of
the record.
The flow rate associated with each piece of treatment equipment
was calculated from the applied flow rate. In this example, the
applied flow rate is 85 gpm listed under DT, drag tank. The
recycle and blowdown flow rates (flow rates for column B and
columns C through E, respectively) were calculated from the
applied flow rate based upon the achievable recycle rates for the
particular metal and process type. Achievable recycle rates and
applied flows are presented in Section IX. The flow rate in
columns C through E are equal to the normalized discharge
allowance multiplied by the mass of metal poured at this model
plant.
410
-------
Investment and annual costs were calculated for each piece of
equipment based upon flow rate and wastewater characteristics.
Data sets used to calculate investment and annual costs for each
treatment component, including design assumptions and supporting
cost information, are included in Section 22.43 of the record.
Those data sets were used to calculate investment, energy, and
chemical costs by linearly interpolating between data points.
Investment costs include the cost of installed capital equipment,
15 percent of the installed equipment cost for contingency, 15
percent of the installed equipment cost for engineering, and 10
percent of the installed equipment cost for contractor's fee.
Operation and maintenance (0&M) costs were based primarily on a
percentage of investment costs. Base O&M costs were figured as 6
percent of investment, plus a maximum additional 4 percent o£
investment prorated to the number of shifts per day the plant
operates, i.e., a plant that operates one shift per day had O&M
costs of 6 percent + (1/3)4 percent = 7.33 percent.
The above formula models data comparing labor cost to total
installed capital cost presented in "Estimating Water Treatment
Costs, Volume 2," EPA 600/2-?6-82b. In addition to the base O&M
cost, additional costs were assumed for batch systems which
require more labor than continuous systems because of manual
chemical addition and surface skimming requirements.
EPA conducted a survey of actual metal molding and casting sludge
disposal costs in 1981. The median sludge disposal cost for the
52 plants providing data was $4.70 per ton. EPA also reviewed
sludge disposal costs contained in a draft report prepared for
EPA's Office of Solid Waste entitled "RCRA Risk/Cost Policy Model
Project, Phase 2 Report." Based on this report, EPA projected
that sludge disposal costs would be about $21.00 per ton
including both disposal site costs and transportation to a
disposal site located 50 miles away. Because metal molding and
casting sludges are not listed as hazardous by EPA at this time
and because tests show that these wastes are not hazardous as
defined by the EP toxicity test, EPA used sludge disposal cost
information applicable to nonhazardous waste. Rather than use
the 1981 industry data, the Agency based its estimates of sludge
disposal on a cost of $21.00 per ton. Oil disposal costs are
based on an oil disposal fee of $28.60 per ton. This disposal
cost is based on the median disposal cost at six metal molding
and casting plants surveyed in 1981, scaled up to first quarter
1983 dollars.
Monitoring costs are based upon the following monitoring
frequencies:
Metals,
Conventionals, and
Nonconventionals
Batch Treatment Systems 2 times/month
Continuous Treatment Systems 4 times/month
411
-------
The estimated sampling frequencies are based in part upon a
document entitled "Minimum Monthly Sampling Frequency," located
in Section 22.43 of the record, and commonly required sampling
frequencies specified in existing permits. Annual monitoring
costs include both the cost of analysis and shipment of samples
to a contract laboratory.
Model plant costs for each regulatory option under consideration
for each segment were included in the public record of this
rulemaking in Section 22.43. Those record materials were
prepared in support of the February 14, 1985 notice of
availability, and were available for public review at that time.
After public review of the February 15, 1985 notice of
availability and supporting record materials, several public
comments were received questioning EPA's compliance cost
estimating assumptions. In general, commenters tended to be in
agreement with EPA's capital cost estimates but felt that the
annual cost estimates were understated. Specific comments and
written responses can be found in the Comment Response Documents,
record Section 22.75.
EPA carefully reviewed each comment and has made the following
adjustments to the model plant cost estimates,
O&M Costs - As discussed above, EPA had originally assumed that
O&M costs would be based on between 6 to 10 percent of the
installed capital cost, as a function of number of shifts per day
the treatment plant operated. Additional labor costs were
included for batch treatment systems where labor intensive manual
operations were required.
Comments were received stating that while the above assumptions
were adequate for operating labor at larger model plants, very
small model plants that required a relatively small capital
expenditure may not have been provided with adequate labor costs
using the Agency's initial methodology. The commenters also
asserted that maintenance materials had not been provided for.
The Agency reviewed the commenters1 assertions and made two
adjustments to the O&M estimating methodology. After reviewing
the source of the original 6 to 10 percent of capital cost for
O&M cost assumption, "Estimating Water Treatment Costs, Volume
2," the Agency determined that the initial estimate did not
include costs for maintenance materials. Costs provided in the
above reference suggest that 2 percent of the installed capital
cost per year is an adequate estimate of maintenance material
expenditures. Therefore, the Agency added 2 percent of the
installed capital cost to the annual model plant costs to account
for maintenance materials costs. The Agency also determined that
the initial assumption did not provide adequate operating labor
at very small plants. Therefore, EPA adopted a minimum operating
labor requirement at very small model plants based upon operating
practices observed during sampling trips and site visits at
plants in this and similar categories. The minimum operating
labor requirements at very small plants were assumed to be 0.5
412
-------
hrs/shift at Option 1 level treatment, 0.8 hrs/shift at Option 2
level treatment, and 1.0 hrs/shift at Option 3 and Option 4 level
treatment.
Monitoring Costs - Comments were received that the cost per
analysis onwhich the Agency had based annual monitoring costs
were too low. The initial costs were based on pricing data
provided by a commercial laboratory. However, it could not be
determined whether the costs were based on a bulk contract rate
or on a single sample rate. Therefore, the Agency solicited
additional pricing data from two other commercial laboratories
based on low volume analytical requirements. The original
pricing data were averaged with the data provided by the two
additional laboratories to determine the average cost per
analysis currently used.
In addition, costs associated with monitoring for priority
organic pollutants are no longer included in the annual
monitoring cost requirements. Priority organic pollutants are
not specifically regulated at direct discharging facilities. The
Agency believes that indirect discharging facilities will choose
to monitor for oil and grease as an alternate monitoring
parameter, rather than monitor for priority organic pollutants.
The use of oil and grease as an alternate monitoring parameter is
discussed in Section XIII.
Change in_ Design Basis - The design bases of some of the
treatment options have been adjusted for the purpose of
estimating compliance costs. Potassium permanganate addition has
been included at Option 2 level treatment in the following
process segments:
Aluminum dust collection
Aluminum melting furnace scrubber
Copper dust collection
Copper melting furnace scrubber
Ferrous melting furnace scrubber
Zinc melting furnace scrubber
The addition of potassium permanganate oxidation to these six
segments brings to 10 the number of process segments with
potassium permanganate addition. Potassium permanganate
oxidation was included in the Option 2 compliance costs for
aluminum die casting, ferrous dust collection, ferrous wet sand
reclamation, and zinc die casting presented in the record of the
February 15, 1985 notice of availability. While the Option 2
treatment effectiveness concentrations for total phenols are
based on the incidental removal of phenols in an oil removal,
lime and settle treatment system, some plants may have to employ
chemical oxidation to meet the phenol limitations and standards.
Therefore, Option 2 compliance costs for the aforementioned 10
process segments include costs for potassium permanganate
oxidation. Costs for this technology have been included in these
segments to ensure that the compliance costs reflect the costs
that would be incurred at plants with concentrations of phenol
413
-------
that require additional removal beyond that provided by oil
removal and lime and settle treatment.
The design basis for the treatment systems in the die casting
process segments have been changed so that the full measure of
Option 2 treatment (chemical emulsion breakingr skimming,
chemical oxidation and lime and settle treatment) is now provided
inside the recycle loop. This change has been made in response
to public comment that the quality of die casting process water
after simple settle treatment may not make it suitable for
recycle. Including Option 2 treatment inside the recycle loop
will ensure that the process water recycled to the die casting
process is of suitable quality for reuse.
Changes rn Applied and Discharge Flow Rates - In response to
public comments on the applied and discharge flow rates which
form the bases of mass limitations, the Agency has reexamined all
flow data in question in its applied flow data base* This review
resulted in the adjustment of some of the median applied flow
rates, and the resulting discharge flow rates that are based on
the median applied flow rate and achievable recycle rate. The
final applied flows and discharge flows for each process segment
are shown in Table IX-1.
Model plant costs are estimated based on the flow rate of water
recycled and treated at the model plant. In segments where the
applied and discharge flows were changed based on review of the
applied flow data base, model plant costs were adjusted to
reflect those changes in applied and discharge flow. The above
adjustments were made by developing cost curves for each
treatment option in the segments where applied flow rates
changed. Separate curves were developed for capital and annual
costs. The cost estimated based on the unrevised applied flow
rates for each employment size group within the segment were used
to form the data points on a cost vs. flow curve. The revised
costs were then estimated from the cost vs. flow curve based on
the revised applied flow rates.
After making the above changes, EPA finalized its model plant
treatment costs. Model plant costs for treatment options 1
through 5 are presented in Tables VIII-2 through VIII-6. Those
tables present investment and annual costs for each of the
different plant sizes within each subcategory segment.
Utilization Factors
Utilization factors were used to determine that portion of the
model technologies that is already in-place. Utilization factors
were calculated by examining all of the treatment-in-place survey
data for plants within a particular subcategory, plant size, and
discharge mode (cell). For example, if a settling tank is
required in the treatment scheme of a particular treatment
option, for a particular cell, and three out of the 10 plants in
the survey data base for that cell report they have settling
tanks in place, a utilization factor of 0.3 (3/10) was assigned
414
-------
to settling tanks for that particular treatment option and cell.
More effective unit operations can substitute for less effective
unit operations in the calculation of utilization factors. For
example, if a plant has a clarifier in placer but only a settling
tank is required, the clarifier can substitute for the settling
tank .
Utilization factors for recycle equipment such as pumps and
piping are based on the percentage of plants with demonstrated
recycle within each cell. This is an accurate estimate of
treatment equipment in-place because most plants with recycle
equipment in-place are recycling at or above the recycle rates
that form the basis of discharge flow reduction in the model
technology options. Those remaining plants recycling at rates
slightly below the recycle rates that form the basis of discharge
flow reduction may need to increase their recycle rate. However,
as this will generally only require an approximate 5 to 15
percent increase in flow through existing equipment, EPA has
assumed that existing equipment will be able to absorb this
increase in capacity for the purposes of estimating levels of
treatment in-place.
A complete list of the utilization factors used for the
calculation of regulatory compliance costs and reference
materials detailing acceptable treatment component substitutions
for the purposes of calculating utilization factors are included
in Section 22.43 of the record for this rulemaking.
Projected Number of Dischargers
The projected number of dischargers in each cell of the metal
molding and casting category is presented in Table VIII-7. A
summary of the procedure used to make these estimates follows. A
detailed discussion of the statistical development of these
estimates is provided in Section 22,25 of the record. The first
step in estimating the projected number of dischargers was to
tabulate the actual number of dischargers known to exist in the
metal molding and casting data base. A data base to industry
scale-up ratio was calculated for each subcategory/employment
size group by dividing a projected distribution of wet plants in
the industry calculated from 1984 Penton Census data by the
distribution of wet plants in the metal molding and casting data
base. The projected number of processes in the industry was then
calculated by multiplying the distribution of processes in the
metal molding and casting data base by the scale-up ratios just
discussed.
Calculation of_ Industry Costs
To better illustrate the calculation of industry costs, a sample
industry cost calculation follows.
415
-------
Example Calculation: Option 3 (recycle, and chemical
precipitation, settling, and filtration of blowdown) industry
costs for the ferrous subcategory, dust collection scrubber
process, 10-49 employees, indirect discharge model. The model
plant costs for this particular option for this cell are
presented in Table VIII-1. To calculate the total industry cost,
the model plant cost is first broken down into two parts: an in-
place cost that reflects the value of components already in-place
and incremental costs associated with needed equipment that is
not yet in-place. The breakdown of the model plant costs into
in-place and incremental components is accomplished with the use
of utilization factors. The utilization factors for the cell of
interest are {see record, Section 22.43);
DT
RTP-A
BT4
MB4
CF
0
0.8
0.2
0
0
The incremental portion of the model plant cost is calculated by
multiplying the fraction of the model plant cost attributed to
each individual component by one minus the utilization factor:
Investment Costs:
Component
DT
RTP-A
BT4
MB4
CF
Total
Fraction
of Model
Plant Cost
Attributed
0- Component
0.58
0.20
0.09
0.06
0.07
1.00
Utilization
Factor (U.F.) 1-U.F.
0 1
0.8 0,2
0.2 0.8
0 1
0 1
Incremental
Portion
of Model
Plant. Cost
0.58
0.04
0.07
0.06
0.07
0.82
416
-------
Annual Costs:
Fraction
of Model
Plant Cost
Attributed
Cgmgonent to Component
DT
RTP-A
BT4
MB4
CF
Monitoring
Total
0.45
0.13
0.07
0.08
0.10
0.17
1.00
Utilization
Factor (U.F.) 1-U.F.
0 1
0.8 0.2
0.2 0.8
0 1
0 1
1
Incremental
Portion
of Model
Plant Cost
0.45
0.03
0.06
0.08
0.10
0.17
0.89
Thus, as shown in the above tables, 82 percent of the capital
model plant cost for Option 3 treatment at a ferrous dust
collection scrubber process with 10-49 employees is incremental,
18 percent of the cost is attributed to treatment in-place. At
the same model plant, 89 percent of the annual model plant cost
is incremental, 11 percent is associated with equipment in-place.
Industry costs are calculated by multiplying the incremental
model plant costs by the projected number of dischargers in the
cell of the industry represented by the model plant. The
calculation of industry costs and associated impacts also
accounts for cost savings through central treatment and the costs
associated with segregating noncontact cooling water from process
wastewater. The calculation of industry-wide compliance costs
based on these factors is discussed in the Economic Analysis of
Final Effluent Limitations Guidelines and Standards for the Metal
Molding and Casting Industry (U.S. EPA, September 1985). A
discussion of the methodology used to estimate segregation costs
and central treatment cost savings follows.
Segregation Costs
The approach chosen to estimate segregation costs was to select a
random sample set of 20 plants from the data base composed of
data collection portfolios from metal molding and casting plants
that use process water. Segregation costs were then estimated
individually for each plant in the sample group, if required.
The results of the random survey indicate that 30 percent of the
plants in the category will incur an average increase of about 10
percent over base model plant investment costs as a result of
wastewater segregation requirements. The method used to arrive
at this conclusion is described in more detail below.
First, the sample set of 20 plants was selected at random from
the DCP data base. This was done by obtaining a list of all 420
wet plants in the DCP data base, in order of plant code. Then a
list of random numbers between one and 420 was obtained. For
each random number i, the ith plant on the list of wet DCP's was
417
-------
selected for review.
Six of the plants selected for review required segregation of
noncontact cooling water. Those six plants, along with estimated
segregation costs and the percent increase over a base model
treatment system are presented in Table VIII-8. Estimated
segregation costs are based on the following assumptions:
Case A: Foundry process water is directed to a storm drain or
sewer that also collects noncontact waters/ which are
then discharged to surface water or to a POTW without
treatment. Plants 04688, 22121, 28822, and 05333 were
found to have such configurations. In this case costs
were included for rerouting the process water from its
source to a new treatment system, assumed to be 500
feet away, unless the DCP specified otherwise. Costs
include:
o 500 feet of appropriately-sized PVC piping; pipe
diameter provided was that necessary to
accommodate 110 percent of the maximum wastewater
flow volume at 2 to 3 feet per second
o 20 percent of installed cost for valves, elbows,
fittings, etc.
o 3.7 to 4,8 labor hours per 100 feet of pipe for
installation, depending on pipe size
Case B: Significant amounts of noncontact cooling water are
treated along with foundry process waters in a common
treatment system. Plants 10865 and 05117 had such
configurations. In this case, costs were included for
rerouting the noncontact cooling water around the
treatment system, by continuing the existing noncontact
cooling water line. In addition, costs were provided
for new piping to take the process water from its
process of origin to the treatment system. For plant
05117, this was PVC pipe, with costs similar to case A.
For plant 10865, buried concrete pipe was required to
continue the existing line; a similar arrangement was
required for the process water because of the very high
flow rates. This arrangement included;
o 500 feet of trench and concrete pipe required to
reroute noncontact water around existing system;
1,000 feet required to carry the process water to
the treatment system
o Costs for trench excavation, pipe installation,
trench backfill, and grading were included
o Two standard headwalls, two wing-type headwalls,
and two concrete manholes were provided.
418
-------
All investment and labor costs were determined using Richardson
Rapid Cost Estimation System (1980), The costs were scaled up to
first-quarter 1983 dollars using the Chemical Engineering
Magazine Economic Indicator Index {October 29, 1984). Finally,
the following fees were added as a percentage of the total
investment: engineering at 10 percent, contingency at 15
percent, and contractor's fee (overhead and profit) at 15
percent. Additional annual costs were assumed to be negligible.
Central Treatment Costs
Central treatment of wastewater generated by metal molding and
casting operations is a viable and demonstrated treatment
alternative at plants with more than one wet metal molding and
casting process. To estimate the potential cost savings that can
be obtained through central treatment of wastewater, the Agency
has identified a cross section of five representative model
plants with differing combinations of processes (raw waste
characteristics) and sizes (economies of scale). Compliance
costs based on a frequently used central treatment configuration
have been developed for those segments.
The Agency calculated compliance costs based on central treatment
for five combinations of process segments shown on Table VIII-9,
The combinations in Table VIII-9 are combinations of actual
operations commonly found at plants within the respective
subcategories,
The central treatment configuration for which compliance costs
have been estimated consists of a combined recycle system where
process water is collected from each segment, treated (settling,
followed by either acid or caustic addition), and recycled back
to the water intake manifold for each process. Slowdown from the
combined recycle system is treated using lime and settle
treatment technology. This configuration was chosen for the
analysis of central treatment cost savings because it reflects
most closely the physical configuration of existing metal molding
and casting plants (especially large plants) with central
treatment facilities. The compliance costs for this central
treatment configuration were calculated in the same manner as the
model plant costs. A detailed set of step-by-step calculations
documenting these costs is available in Section 22.34 of the
record.
Central treatment cost savings are presented in tabular form on
Table VIII-9. In summary, central treatment consisting of
combined recycle and blowdown treatment at multi-process metal
molding and casting plants, provides an average 29 percent
capital and 36 percent annual treatment cost savings over
completely segregated treatment systems.
419
-------
POLLUTANT REMOVAL ESTIMATES
The quantities of pollutants removed by each treatment option
were estimated based on a similar methodology as used for cost
estimation. Pollutant removals were estimated for the same model
plants established for cost estimation. A model plant was
established for the five employment size groups (less than 10
employees, 10-49 employees, 50-99 employees/ 100-249 employees,
and greater than 250 employees) in each process segment, EPA
estimated total pollutant removal benefits by first estimating
the mass of pollutants discharged by each model plant at each
treatment option considered. By multiplying these estimates by
the number of plants within the industry represented by a
specific model, the mass discharges of the sections of the
industry represented by each model were established. Pollutant
removal benefits in going from current discharge levels to a
discharge option considered, or in going from one treatment
option to another were calculated by arithmetic difference once
the pollutant masses discharged at each treatment level were
calculated.
Pollutant mass discharges for each model plant were estimated as
follows. The masses of pollutants in raw wastewater discharges
were estimated based on the average normalized mass generation
rate at sampled plants within each process segment {mass
generation rates are presented in Tables V-30 through V-46).
That is, the mass of pollutant generated per unit mass of metal
poured, per unit mass of sand reclaimed, or per unit volume of
wet scrubber air flow was calculated depending on the normalizing
parameter of interest. This ratio of pollutant mass generated
per unit of production or air flow was multiplied by the
production or air flow for the respective model plant to obtain
the annual pollutant mass generation rate.
The average pollutant mass discharge for each model plant at each
treatment option level was calculated by multiplying the
treatment effectiveness concentrations for each treatment option
(as presented in Section VII) by the annual discharge flow of
water at the respective model plant. The annual discharge flow
of water was calculated by multiplying the normalized regulatory
discharge flow rate {BPT flow) by the appropriate mean annual
production or air flow.
The masses of pollutants currently discharged were estimated
based on the masses of pollutants discharged in raw wastewater
and the masses of pollutants discharged at Option 2 (recycle,
lime and settle). A factor representing the current level of
Option 2 treatment-in-place was developed for each model plant
based on the ratio of in-place investment costs to total
investment costs at Option 2. When this factor was multiplied by
the pollutant removal achieved in going from raw waste to Option
2 effluent, an estimate of pollutant reduction achieved by
current levels of treatment was obtained. These currently
achieved pollutant removals were subtracted from the raw waste
loads to obtain the currently discharged waste loads,
420
-------
Calculations and data sheets documenting the pollutant removal
benefit calculations are included in Section 22.67 of the record.
The pollutant removal estimates for each treatment option are
summarized in Table VIII-10.
ENERGY AND NON-WATER QUALITY IMPACTS
The following are the energy and non-water quality environmental
impacts associated with the final effluent limitations guidelines
and standards for the metal molding and casting category.
Energy Requirements
Estimates of the net increase in electrical energy consumption in
each subcategory at each treatment option are presented in Table
VIII-11. For comparison purposes, the total energy usage by
plants in the metal molding and casting category in 1978 was
estimated to be 31.3 billion kilowatt-hours.
EPA has determined the net increases in electrical energy
consumption for each treatment option by multiplying the
incremental energy consumption for each model plant at a
treatment level of interest by the number of processes in the
industry that the model plant represents. These model plant
subtotals were then summed to obtain the total net increase in
industry energy consumption.
The energy used by new direct and indirect discharging plants
will be similar to the amounts used by existing sources with BAT
level treatment and in compliance with PSES, respectively.
Air Pollution
None of the model processes or treatment technologies that form
the bases of final effluent limitations guidelines and standards
generate or contribute to the generation of any air pollutants.
Therefore/ there will be no impacts on air quality as a result of
pollution control technologies recommended to achieve the
promulgated levels of treatment.
Solid Wasjte
Estimates of the incremental increase in solid waste generation
at each treatment option in each subcategory are presented in
Table VIII-12.
EPA has estimated the incremental increases in solid waste
generation by each treatment option by multiplying the
incremental solid waste generation for each model plant at a
treatment level of interest by the number of processes in the
industry that the model plant represents. These model plant
subtotals were then summed to obtain the total incremental
increase in industry solid waste generation. EPA has assumed
that the solid waste generation rates at new direct and indirect
discharging plants will be similar to the amounts generated by
421
-------
existing sources at BAT level treatment and in compliance with
PSES, respectively.
The Agency examined the solid wastes that would be generated by
metal molding and casting processes using the model treatment
technologies and has concluded that they are not hazardous under
Section 3001 of the Resource Conservation and Recovery Act
(RCRA). This judgement is based on a review of the results of
extensive Extraction Procedure (EP) toxicity tests that were
conducted on metal molding and casting solid wastes (See Sampling
and Analysis o£ Wastes Geriera_ted^ by_ Gray Iron Foundries,
Environmental Protection Agency, EPA 600/4-81-028, Washington,
D.C,, April 1981; and also Harn, R. K., W. C. Boyle, and F. J.
Blaha, "Leachate and Groundwater Quality In and Around Ferrous
Foundry Landfills and Comparisons to Leach Test Results,"
American Foundryman's Society, Des Plaines, Illinois, January,
1985). None of the pollutants for which the extracts in the EP
test are analyzed were found consistently in metal molding and
casting sludges above the allowable concentration (i.e., the
concentration that makes the waste hazardous). Metal molding and
casting wastes are also not listed currently as hazardous under
40 CFR Part 261.11 (45 FR 33121, May 19, 1980; as amended by 45
FR 76624, November 19, 1980). For the above reasons, EPA has not
developed estimates of the costs to dispose of hazardous solid
wastes. EPA has included costs for nonhazardous waste disposal
of $21.00/ton for sludges and $28.60/ton for oily wastes
generated in treating metal molding and casting wastewaters.
Although it is the Agency's view that solid wastes generated as a
result of these regulations are not expected to be classified as
hazardous under the regulations implementing Subtitle C of RCRA,
individual generators of these wastes must test the wastes to
determine if they meet any of the characteristics of hazardous
wastes. See 40 CFR Part 262.11 (45 FR 12732-12733, February 26,
1980),
Should any metal molding and casting wastes be identified as
hazardous, they will come within the scope of RCRA's "cradle to
grave" hazardous waste management program, requiring regulation
from the point of generation to the point of final disposition.
EPA's generator standards require generators of hazardous wastes
to meet containerization, labeling/ recordkeeping, and reporting
requirements. If metal molding and casting facilities dispose of
hazardous wastes off-site, they would have to prepare a manifest
that tracks the movement of the wastes from the generator's
premises to an appropriate off-site treatment, storage, or
disposal facility. See 40 CFR Part 262.20 (45 FR 33142, May 19,
1980; as amended at 40 FR 86973, December 31, 1980). The
transporter regulations require transporters of hazardous wastes
to comply with the manifest system to ensure that the wastes are
delivered to a permitted facility. See 40 CFR Part 263.20 (45 FR
33142, May 19, 1980; as amended at 45 PR 86973, December 31,
1980). Finally, RCRA regulations establish standards for
hazardous waste treatment, storage, and disposal facilities
allowed to receive such wastes. See 40 CFR Parts 264 and 265 (46
422
-------
FR 2802, January 12, 1981; 47 FR 32274, July 26f 1982),
Even though metal molding and casting wastes are not identified
as hazardous/ they still must be disposed of in a manner that
will not violate the open dumping prohibition of Section 4005 of
RCRA. The Agency has calculated, as part of the costs for
wastewater treatment, the cost of model plants of hauling and
disposing of these wastes (using the unit costs noted above) in
accordance with this requirement.
Consumptive Mater Loss
Table VIII-13 presents the evaporative water losses that EPA
projects will result from the application of high rate recycle in
the metal molding and casting category. The evaporative losses
were estimated based on an assumed 2 percent loss due to
evaporation and drift in those process segments that require
cooling towers.
423
-------
Table VIII-1
METAL HOLDING AND CASTING INDUSTRY GUIDELINES MODEL COSTS
(First Quarter 1983 Dollars)
Metal Category:
Employee Group:
Process(es):
Ferrous
10-49
Dust Collection
Option No.: 3
Shifts: 1
Air Flow (1,000 scfm): 28.4
Treatment Step
Treatment Component
Flow (gpm)
Investment Costs
Annual Costs:
Capital
Depreciation
O&M
Energy
Sludge Disposal
Oil Disposal
Chemical
Monitoring (Lab)
Totals
A
DT
85
74,330
5,950
7,^30
6,940
50
4,520
0
0
24,890
8
RTP-A
82.5
25,740
2,060
2,570
3,160
300
0
0
20
8,110
C
BT4
2.50
11,400
910
1,140
1,250
0
440
10
0
3,750
D
HB4
2.50
6,960
560
700
2,040
10
0
0
150
3,460
E
CF
2.50
8,650
X
X
X
X
X
X
X
2,480
Model
Cost
ToJ^gls
127,080
9,480
11,840
13,390
360
4,960
10
170
2,760
45,450a
Key: X - Values were not itemized.
Total includes monitoring costs.
DT - Drag Tank
RTP-A - Recycle to process, acid addition
MB4 - Mixer
BT4 - Batch settling tank (4 hour
retention)
CF - Cartridge filter
-------
TABLE VII1-2
MODEL PLANT COSTS - OPTION 1
ALUMINUM SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OP EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
ALUMINUM CASTING CLEANING
10-49
100-249
250+
ALUMINUM CASTING QUENCH
10-49
50-99
100-249
250+
ALUMINUM DIE CASTING
10-49
50-99
100-249
250+
ALUMINUM DUST COLLECTION
10-49
100-249
250+
ALUMINUM GRINDING SCRUBBER
100-249
250 +
ALUMINUM INVESTMENT CASTING
10-49
100-249
250+
ALUMINUM MELTING FURNACE SCRUBBER
10-49
50-99
100-249
250+
ALUMINUM MOLD COOLING
10-49
50-99
100-249
250+
26230
59410
36990
26160
26000
28480
55970
59790
44630
44630
64260
26000
26620
48370
71410
228230
42930
42930
42930
174920
440590
87460
48810
88020
138320
70490
4200
9440
5050
8140
6660
9130
9430
11510
6110
7300
8170
4310
4630
7910
10840
32910
8770
8490
9610
25590
79740
14980
9800
14320
19360
12160
Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenence labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
425
-------
TABLE VIII-2 continued
MODEL PLANT COSTS - OPTION 1
COPPER SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
^m-lrv-f^^m ^ ^* w **-^ ^ 4**-^^-^ ^M-**-^ ^ A^. ^* ^_ ^> ^* ^_ ^ ^B-^k^^-^-^ *
COPPER CASTING QUENCH
10-49
50-99
100-249
250+
COPPER DIRECT CHILL CASTING
INVESTMENT COSTS* ANNUAL COSTS**
10-49
50-99
100-249
250+
COPPER DUST COLLECTION
10-49
50-99
100-249
250+
COPPER GRINDING SCRUBBER
50-99
100-249
250+
COPPER INVESTMENT CASTING
100-249
COPPER MELTING FURNACE SCRUBBER
50-99
250+
COPPER MOLD COOLING
10-49
50-99
100-249
250+
29700
113430
90750
195400
70240
160740
236660
571390
985750
1264430
117690
63960
164300
46740
2693C
26000
26930
56450
83730
246990
66590
369040
271945
707204
203980
6840
18090
13960
39140
12920
30990
47350
134710
248480
327280
22580
11700
43880
10200
4440
4770
4860
8850
14740
60340
13900
68760
50640
125060
38040
Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenence labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
426
-------
TABLE VII1-2 continued
MODEL PLANT COSTS - OPTION 1
FERROUS SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
FERROUS CASTING CLEANING
<10 28950 4360
50-99 26090 3950
100-249 , 55100 6760
250+ 107050 15350
FERROUS CASTING QUENCH
10-49 37810 6300
50-99 81380 13150
100-249 142580 25960
250+ 175930 29520
FERROUS DUST COLLECTION
10-49
50-99
100-249
250 +
FERROUS GRINDING SCRUBBER
10-49 43040 5760
50-99 65250 7780
100-249 157020 22110
250+ 229680 30970
FERROUS INVESTMENT CASTING
10-49 27980 5120
FERROUS MELTING FURNACE SCRUBBER
<10 182800 24340
10-49 239970 32900
50-99 182800 23120
100-249 283170 39370
250+ 797135 135930
FERROUS MOLD COOLING
100-249 359700 37880
250+ 339730 47850
FERROUS SLAG QUENCH
10-49 54280 8870
50-99 53780 8700
100-249 137900 23470
250+ 276710 74470
FERROUS WET SAND RECLAMATION
100-249
250+
Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenence labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring*
427
-------
TABLE VIII-2 continued
MODEL PLANT COSTS - OPTION 1
MAGNESIUM SUBCATEGQRY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
MAGNESIUM CASTING QUENCH
10-49
50-99
MAGNESIUM COLLECTION
10-49
MAGNESIUM GRINDING SCRUBBER
10-49
26550
48860
34340
34340
34340
6120
10100
5160
5320
5100
Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenance labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
428
-------
TABLE VIII-2 continued
MODEL PLANT COSTS - OPTION 1
ZINC SUBCATEGQRY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
2INC CASTING
<10
10-49
50-99
100-249
250+
2INC DIE CASTING
10-49
50-99
100-249
250+
2INC MELTING FURNACE SCRUBBER
50-99
100-249
250+
2INC MOLD COOLING
10-49
50-99
100-249
250 +
26430
33820
36130
51300
38740
139500
79460
69720
56000
65220
101910
92700
4600
6040
6280
10450
6320
18940
10190
8840
5660
5i60
17i50
14590
•Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenenee labor and materials,
sludge and oil disposal, energy, chemicalsf and monitoring.
429
-------
TABLE VII1-3
MODEL PLANT COSTS - OPTION 2
ALUMINUM SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OP EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
ALUMINUM CASTING CLEANING
10-49
100-249
250+
ALUMINUM CASTING QUENCH
<10
10-49
50-99
100-249
250+
ALUMINUM DIE CASTING
10-49
50-99
100-249
250+
ALUMINUM DUST COLLECTION
10-49
100-249
250+
ALUMINUM GRINDING SCRUBBER
100-249
250+
ALUMINUM INVESTMENT CASTING
10-49
100-249
250+
ALUMINUM MELTING FURNACE SCRUBBER
<10
10-49
50-99
100-249
250+
ALUMINUM MOLD COOLING
<10
10-49
50-99
100-249
250+
32630
65990
43430
32560
32400
34880
62370
66190
27820
37830
40710
55690
51290
51290
71580
32400
33020
54310
79220
244380
52710
52710
52710
184750
482420
93240
55620
93780
139950
77020
4890
17810
6690
8680
7480
9610
11150
15570
15930
18510
25930
34840
9650
10770
14570
5110
5110
9500
12650
33470
15990
15570
19820
35600
92210
20520
12570
19580
28030
16080
Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenance labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
430
-------
TABLE VII1-3 continued
MODEL PLANT COSTS - OPTION 2
COPPER SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
- OP EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
COPPER CASTING
10-49
50-99
100-249
250+
COPPER DIRECT CHILL CASTING
10-49
50-99
100-249
250+
COPPER DUST COLLECTION
10-49
50-99
100-249
250+
COPPER GRINDING
50-SS
100-249
250+
COPPER INVESTMENT CASTING
100-249
COPPER MELTING PDRNACE SCRUBBER
50-99
250+
COPPER MOLD COOLING
10-49
50-99
100-249
250+
36100
119880
97150
202220
76640
168500
246270
584730
998370
1274590
126090
70810
174200
53270
33330
32400
33330
63080
93240
280710
70420
380110
281920
723340
212330
7400
23670
19510
47370
15780
36390
53420
139100
253560
332900
26020
15100
50510
13500
5260
5600
5870
10580
21430
70870
18530
75590
57600
128640
44290
Mnvestment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenence labor and materialsf
sludge and oil disposal, energy, chemicals, and monitoring.
431
-------
TABLE VIII-3 continued
MODEL PLANT COSTS - OPTION 2
FERROUS SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
FERROUS CASTING CLEANING
<10
50-99
100-249
250+
FERROUS CASTING QUENCH
10-49
50-99
100-249
250+
FERROUS DUST COLLECTION
10-49
50-99
100-249
250+
FERROUS GRINDING SCRUBBER
10-49
50-99
100-249
250+
FERROUS INVESTMENT CASTING
10-49
FERROUS MELTING FURNACE SCRUBBER
<10
10-49
50-99
100-249
250+
FERROUS MOLD COOLING
100-249
250+
FERROUS SLAG QUENCH
10-49
50-99
100-249
250+
FERROUS WET SAND RECLAMATION
100-249
250+
INVESTMENT COSTS*
35350
32490
61630
114270
44210
87780
149200
182700
118430
138330
221450
643460
49450
71890
164760
237980
31940
195690
261220
195690
293260
850580
368190
348030
60850
60340
145730
286780
148500
862420
ANNUAL COSTS**
4950
4510
9830
20800
7110
18720
28920
34470
21610
25070
69160
235360
8830
10790
28000
31610
6280
27600
36980
26350
43770
155390
40650
49230
11930
11710
26660
75530
28010
218950
*Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenence labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
432
-------
TABLE VIII-3 continued
MODEL PLANT COSTS - OPTION 2
MAGNESIUM SUBCATEGQRY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OP EMPLOYEES INVESTMENT COSTS* ANNUAL COSTS**
MAGNESIUM CASTING QUENCH
10-49 32950 6950
50-99 55260 11100
MAGNESIUM DUST COLLECTION
10-49 40740 5980
MAGNESIUM GRINDING SCRUBBER
<10 40740 6170
10-49 40740 5980
Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenence labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
433
-------
TABLE VIII-3 continued
MODEL PLANT COSTS - OPTION 2
ZINC SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OP EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
ZINC CASTING QUENCH
<10
10-49
50-99
100-249
250+
ZINC DIE CASTING
10-49
50-99
100-249
250+
ZINC MELTING FURNACE SCRUBBER
50-99
100-249
250+
ZINC MOLD COOLING
10-49
50-99
100-249
250+
32830
40220
42530
57750
45140
27600
30180
43150
32910
149240
82060
71980
61990
71520
108830
99560
5750
7780
7990
14810
9210
16570
18090
34490
18980
29640
16980
14260
6460
8780
22460
17960
*Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs Include operation and maintenence labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
434
-------
TABLE VIII-4
MODEL PLANT COSTS - OPTION 3
ALUMINUM SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
ALUMINUM CASTING CLEANING
10-49
100-249
250+
ALUMINUM CASTING QUENCH
<10
10-49
50-99
100-249
250+
ALUMINUM DIE CASTING
10-49
50-99
100-249
250+
ALUMINUM DUST COLLECTION
10-49
100-249
250+
34680
74350
46350
34600
34440
37120
64820
68840
29860
40040
42950
58340
54140
54140
76760
6770
21140
9070
12530
8840
12250
13700
18130
17500
21290
29100
38070
11680
13250
17230
ALUMINUM GRINDING
100-241
250+
ALUMINUM INVESTMENT CASTING
10-49
100-249
250+
ALUMINUM MELTING FURNACE SCRUBBER
10-49
50-99
100-249
250+
ALUMINUM MOLD COOLING
10-49
50-99
100-249
250+
64660
93450
280610
56340
56340
56340
207060
514550
99640
58800
100410
151340
82070
12420
17660
47300
21620
17790
22980
44500
106770
28130
14670
22990
31050
18850
*Investment coats include Installed equipment, contingency, engineering,
and contractor fees.
"Annual costs Include operation and maintenence labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
435
-------
TABLE VIII-4 continued
MODEL PLANT COSTS - OPTION 3
COPPER SOBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
COPPER CASTING QUENCH
10-49
50-99
100-249
250+
COPPER DIRECT CHILL CASTING
INVESTMENT COSTS* ANNUAL COSTS**
10-49
50-99
100-249
250+
COPPER DUST COLLECTION
10-49
50-99
100-249
250+
COPPER GRINDING SCRUBBER
50-99
100-249
250+
COPPER INVESTMENT CASTING
100-249
COPPER MELTING FURNACE SCRUBBER
50-99
250 +
COPPER MOLD COOLING
10-49
50-99
100-249
250+
38140
125450
100460
212320
79290
184840
267450
620680
1044880
1325390
134260
74120
183740
55720
74820
103000
304460
75750
407550
301920
772330
227600
11100
25020
22170
50910
18350
52050
60090
160890
282110
355300
28260
18120
55670
17580
14510
25800
81050
27930
85310
70180
148210
53340
Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenance labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
436
-------
TABLE VIII-4 continued
PLANT COSTS - OPTION 3
FERROUS SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
CASTING CLEANING
<10
50-99
100-249
250+
FERROUS CASTING QUENCH
10-49
50-9§
100-249
250+
COLLECTION
10-49
50-99
100-249
250+
FERROUS GRINDING SCRUBBER
10-49
50-99
100-249
250+
INVESTMENT CASTING
10-49
FERROUS MELTING FURNACE SCRUBBER
<10
10-49
50-99
100-249
250+
FERROUS MOLD COOLING
100-249
250+
FERROUS SLAG QUENCH
10-49
50-99
100-249
250+
FERROUS WET SAND RECLAMATION
100-249
250+
INVESTMENT COSTS*
37590
34540
69515
135710
46450
91090
157850
192530
127080
147980
243180
674360
53850
80640
187650
262600
38520
213960
282930
213960
317250
889990
313390
372650
69120
68510
166910
316460
174030
947340
ANNUAL COSTS**
8590
6460
12630
28360
9150
22100
32650
31250
24130
29800
79320
254640
11090
14220
37100
42180
8020
40960
44020
33850
53§30
175320
51i70
59600
14320
15030
35830
88660
38540
259260
•Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenance labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
437
-------
TABLE VII1-4 continued
MODEL PLANT COSTS - OPTION 3
MAGNESIUM SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OP EMPLOYEES INVESTMENT COSTS* ANNUAL COSTS**
MAGNESIUM CASTING QUENCH
10-49 34980 8580
50-99 57700 13830
MAGNESIUM DUSf COLLECTION
10-49 42980 8030
MAGNESIUM GRINDING SCRUBBER
10-49
*Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenance labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring*
438
-------
TABLE VIII-4 continued
MODEL PLANT COSTS - OPTION 3
ZINC SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
ZINC CASTING QUENCH
10-49
50-99
100-249
250+
ZINC DIE CASTING
10-49
50-99
100-249
250+
ZINC MELTING FURNACE SCRUBBER
50-99
100-249
250+
ZINC MOLD COOLING
10-49
50-99
100-249
250+
34870
42460
44870
61060
47790
29640
32240
45410
35020
164510
92350
81320
64460
74890
116310
105940
8990
9820
10570
17720
11570
18130
20790
38030
21290
32140
18310
15340
7790
11140
27930
22220
Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenance labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
439
-------
TABLE VII1-5
MODEL PLANT COSTS - OPTION 4
ALUMINUM SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OP EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
ALUMINUM CASTING CLEANING
10-49
100-249
250+
ALUMINUM CASTING QUENCH
10-49
50-99
100-249
250+
ALUMINUM DIE CASTING
10-49
50-99
100-249
250+
ALUMINUM DUST COLLECTION
10-49
100-249
250+
ALUMINUM GRINDING SCRUBBER
100-249
250+
ALUMINUM INVESTMENT CASTING
10-49
100-249
250+
ALUMINUM MELTING FURNACE SCRUBBER
<10
10-49
50-99
100-249
250+
ALUMINUM MOLD COOLING
10-49
50-99
100-249
250+
45020
44750
47430
77300
82460
40910
51170
54290
71960
81330
116430
339560
119220
73250
119860
174820
99570
17130
12320
15910
17490
21890
21040
25020
32790
41830
16940
23140
53830
33140
18320
26970
34610
22640
Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenence labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
440
-------
TABLE VII1-5 continued
MODEL PLANT COSTS - OPTION 4
COPPER SUBCATEGORy
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
COPPER CASTING
10-49
50-9§
100-24f
250+
COPPER DIRECT CHILL CASTING
48790
144210
116480
233570
92910
10-49
50-99
100-249
250+
COPPER DOST COLLECTION
10-49
50-99
100-249
250+
COPPER GRINDING SCRUBBER
50-99
100-249
250+
COPPER INVESTMENT CASTING
100-249
COPPER MILTING fURNACE
50-99
250+
COPPER MOLD COOLING
10-49
50-99
100-249
250+
88760
456960
341190
851520
259100
15720
30110
30650
60730
22110
34190
95850
80030
161350
61630
*Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual coats include operation and maintenence labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
441
-------
TABLE VIII-5 continued
MODEL PLANT COSTS - OPTION 4
FERROUS SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
- NUMBER OF EMPLOYEES
CASTING CLEANING
INVESTMENT COSTS* ANNUAL COSTS**
50-99
100-249
250+
FERROUS CASTING QUENCH
10-49
50-99
100-249
250+
FERROUS DUST COLLECTION
10-49
50-99
100-249
250+
FERROUS GRINDING SCRUBBER
10-49
50-99
100-249
250+
INVESTMENT CASTING
10-49
FERROUS MELTING FURNACE SCRUBBER
147880
169080
265420
733640
10-49
50-99
100-249
250+
FERROUS MOLD COOLING
100-249
250+
FERROUS SLAG QUENCH
10-49
50-99
100-249
250+
FERROUS WET SAND RECLAMATION
100-245
250+
49120
238120
312620
238120
350860
960170
224180
1106240
28420
35320
89930
261100
11510
56200
56780
46000
67710
181920
43310
276950
•investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenence labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
442
-------
TABLE VIII-5 continued
MODEL PLANT COSTS - OPTION 4
MAGNESIUM SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OP EMPLOYEES INVESTMENT COSTS* ANNUAL COSTS**
MAGNESIUM CASTING QUENCH
10-49 45400 12070
50-99 70180 17690
MAGNESIUM DOST COLLECTION
10-49
MAGNESIUM GRINDING
10-49
Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenance labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
443
-------
TABLE VIII-5 continued
MODEL PLANT COSTS - OPTION 4
ZINC SUBCATEGORY
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
2 INC CASTING
<10
10-49
50-99
100-249
250+
ZINC DIE CASTING
10-49
50-99
100-249
250+
ZINC MELTING FURNACE SCRUBBER
50-99
100-249
250+
ZINC MOLD COOLING
10-49
50-99
100-249
250+
INVESTMENT COSTS*
45410
53800
56780
77080
61410
40690
43290
56860
46070
184120
104980
92720
79440
91100
136160
125030
ANNUAL COSTS**
13110
13390
14370
21600
15330
21670
24510
41720
24820
41670
25170
21440
10790
14960
33790
27450
•Investment costs include installed equipment, contingency, engineering,
and contractor fees.
**Annual costs include operation and maintenance labor and materials,
sludge and oil disposal, energy, chemicals, and monitoring.
444
-------
TABLE VII1-6
MODEL PLANT COSTS - OPTION 5
ALL SUBCATEGORIES
FIRST QUARTER 1983 DOLLARS
SEGMENT - NUMBER OF EMPLOYEES
INVESTMENT COSTS* ANNUAL COSTS**
ALUMINUM GRINDING SCRUBBER
100-249
250+
COFFER GRINDING SCRUBBER
50-99
100-249
250+
FERROUS GRINDING SCRUBBER
10-49
50-99
100-249
250+
MAGNESIUM GRINDING SCRUBBER
<10
10-49
20600
21240
21560
20600
21560
37620
57550
143050
215310
29100
29100
2540
2350
2410
3200
3250
3970
6310
19540
23200
3120
3120
^Investment costs include installed equipment, contingency, engineering,
and contractor fees.
"Annual costs include operation and maintenance labor and materials,
sludge and oil disposal, energy, and chemicals. NO monitoring
costs are included at option 5.
445
-------
Table VIII-7
PROJECTED NUMBER OF ACTIVE WET PROCESSES IN
THE METAL MOLDING AND CASTING INDUSTRY
Employee No
Metal Segment
Ainu in un N.A.
Copper N.A.
-------
Table VIII-? (Continued)
PROJECTED NUMBER OF ACTIVE WET PROCESSES IS
THE METAL MOLDING AND CASTING ISD0STR*
Employee No
Metal Segment group_ Prooeas Pi r eat Indirect Discharge Total
Copper N.A. 10-^9 CQ 12 20 0 32
0 4
0 12
4 16
50-99 CQ 5 3 3 11
0 5
8 13
2 2
2 2
0 5
CQ
DCC
DC
MC
CQ
DCC
uc
GS
MFS
MC
CQ
DCC
UC
1C
GS
MC
CQ
DCC
UC
GS
MFS
MC
12
4
8
4
5
5
5
0
0
2
3
6
3
0
0
3
1
2
0
0
1
2
20
0
4
8
3
0
0
0
0
3
0
0
0
3
5
0
3
0
1
2
0
2
100-249 CQ 3 0 03
0 6
3 6
0 3
3 9
0 3
250+ CQ 1 3 04
0 2
1 2
0 2
1 2
0 4
Ferrous Ductile <10 None
10-49 UC 0 5 5 10
GS 0 5 5 10
50-99 UC 0 0 33
GS 0 0 33
MFS 0 3 36
100-249 CQ 8 0 08
UC 8 11 0 19
MC 8 3 0 11
MFS 8 3 3 14
SQ 11 6 0 17
447
-------
Table VIII-7 (Continued)
PROJECTED NDHBER OF ACTIVE WET PROCESSES HI
THE METJtt, MOLDING AND CASTING INDUSTRY
Metal Serpent
Ferrous Ductile
Employee
Group Process Direct
No
Indirect Discharge Total
250+
Gray
10-49
50-99
100-249
250+
Malleable <10
10-49
CC
CQ
DC
GS
MC
MFS
SQ
WSR
MFS
1
5
9
3
3
6
7
1
DC
MFS
SQ
CQ
DC
GS
MFS
SQ
CC
CQ
DC
GS
MC
MFS
SQ
CC
CQ
DC
GS
MC
MFS
SQ
WSR
Hone
None
10
10
5
0
8
0
8
3
3
3
24
0
3
19
13
5
1
25
5
U
13
21
5
0
0
1
0
0
1
1
0
20
25
0
3
19
0
16
B
3
3
35
8
0
27
19
1
2
23
1
1
15
17
5
0
0
6
0
1
2
2
0
1
5
16
3
4
9
10
1
5
30
0
0
8
3
19
3
3
5
27
3
0
24
16
1
0
21
4
0
14
7
0
35
65
5
3
35
3
43
14
9
11
86
11
3
70
48
7
3
69
10
5
42
45
10
448
-------
labl* ¥111-7 (Continued}
PBOJlCfSD OF ICflfl WET IN
THE METAL HOLDING JVD IHDCSTRY
Employee No
Hstal Segment Group Proceas Direct Ip4jragt Discharge Total
Ferrous Mallea
i 50-99
100-249
250+
UC
MTS
SQ
CQ
cc
uc
GS
MFS
SQ
CC
CQ
DC
GS
MFS
SQ
p**iHHMPBMBM*-
3
0
3
0
3
11
0
0
0
0
J|
5
2
4
5
ff
3
3
3
0
16
5
3
5
0
1
2
0
2
0
5
3
0
0
0
5
0
0
0
1
1
8
0
1
1
8
6
6
3
3
32
5
3
5
1
6
15
2
7
6
Steel <10 cc
10-49 CQ 0 5 5 10
0 5
50-99 CC 3 5 08
0 22
6 14
100-249 CC 3 0 03
6 31
8 30
3 3
3 6
0 6
250+ CQ 8 13 2 23
7 21
0 1
1 1
0 2
0 6
CQ
1C
CC
CQ
UC
CC
CQ
0C
GS
MFS
VSR
CQ
DC
GS
MC
SQ
W5R
0
0
3
8
0
3
14
11
0
3
6
8
6
1
0
0
4
5
5
5
14
8
0
11
11
0
0
0
13
8
0
0
2
2
449
-------
Table ¥111-7 (Continued)
PROJECTED NUMBER OF ACTIVE WET PROCESSES IN
THE METAL MOLDING AND CASTING INDUSTRY
Metal Segment
Magnesium N.A.
Employee
Group Proeea
GS
CQ
DC
GS
CQ
10-H9
50-99
2inc
10-119
50-99
100-249
250*
2
0
0
No
Indjj*eet Pi a charge Total
0 1 1
0
2
2
CQ
DC
CQ
DC
HC
CQ
DC
MFS
MC
CQ
DC
MFS
HC
CQ
DC
MFS
HC
0
0
0
0
0
0
0
0
0
7
k
3
2
2
0
0
t
2
0
15
8
6
9
4
2
2
10
6
7
0
It
t
1
0
0
0
0
2
a
2
0
2
0
6
0
2
2
0
0
2
H
2
6
1
2
0
1
2
2
15
14
6
11
6
2
2
19
14
12
8
T
3
1
2
ley;
Process Code Process
CC
CQ
DCC
DC
UC
GS
Casting cleaning
Casting quench
Direct chill casting
Die casting
Dust collection
Grinding scrubber
Process Code Process
1C
MFS
MC
SQ
MSR
Investment casting
Melting furnace scrubber
Mold cooling
Slag quench
Vet sand reclamation
450
-------
Table VIII-8
ESTIMATED INSTALLED CAPITAL COSTS FOR SEGREGATION OF NONCONTACT COOLING WATER"
Estimated Cost
Percent Increase Over
Base Model Treatment System Cost
Elaafc Code
04666
05117
05333
10865
22121
28222
Average
to Segregate
fi March 198^1
$19,530
11,300
9,690
82,280
19,140
9,690
$25,270
At
Option 1
14.2
22.0
•
10.8
12.3
11.8
At
Option 2
13..
19.6
4.4
10.5
11.5
.JLJl
10.6
At *
Option 3
11.6
18.5
4.0
9.9
10.4
9.7
At
Option 4
14.7
3.7
•
»
7.4
•The option was not considered for that process segment.
••Costs include materials, installation labor and engineering, contingency, and
contractor's fees.
-------
1* Aluminum
2. Copper
3. Copper
4. Ferrous
5. Zinc
Table VIII-9
SELECTED PROCESS SEGMENT COMBINATIONS
FOR CENTRAL TREATMENT COST STUDY
Employee Size Group
100-249
10- lit
tO-19
ProqeaaSegment Coablnation
Casting Quench
Mold. Cooling
Melting Furnance Scrubber
Casting Quench
Direct Chill Casting
Casting Quench
Direct Chill Casting
Hold Cooling
Duat Collection Scrubber
Melting Furnance Scrubber
Slag Quench
Duat Collection Scrubber
Casting Quench
Die Casting
Mold Cooling
Saving8 p*fir Segregated Treatment
Capital Co
«.f
19-9
11.0
26.*
13.0
!5.2
28 .
38.9
16,0
36.0
-------
Table VIII-10
INCREMENTAL POLLUTANT REMOVAL ESTIMATES
DUE TO APPLICATION OF MODEL TREATMENT TECHNOLOGY
Ul
Subcategory
Aluminum
Copper
Ferrous
Magnesium
Zinc
Pollutant
Toxic Pollutants
All Pollutants
Toxic Pollutants
All Pollutants
Toxic Pollutants
All Pollutants
Toxic Pollutants
All Pollutants
Toxic Pollutants
All Pollutants
Pij-ect Discharge (Iba/vr)
Current
Discharge
to Option 2
12
716
154
660
1,610
144,000
4
487
,600
,000
,000
,000
,000
,000
0.331
20.4
,780
,000
Option 2
to
Option 1
2,
1,
20,
6.
61,
46
780
400
700
080
300
0.002
0.085
86
381
-Indirect Discharge (Iba/vr)
Current
Discharge
to Option 2
114
5,450
18
113
2,670
122,000
36
2,410
,000
,000
,100
,000
,000
,000
9.69
308
,500
,000
Option 2
to
Option 3
36
2,110
59
3,330
5,010
46,800
0.
0.
82
586
007
559
-------
Table VIII-11
NET INCREASE IN ELECTRICAL ENERGY CONSUMPTION
DUE TO APPLICATION OF MODEL TREATMENT TECHNOLOGY
Met Increase In Energy Consumption -
Direct Dischargers
million kilowatt-houra/vr
Subcategoj-y
f
Aluminum
Copper
Ferrous
Magnesium
Zinc
Option
1
0.40
6.6
11
0.0011
0.066
Option
2
0.49
6.7
12
0.0011
0.066
Option
1
0.63
8.0
14
0.0014
0.088
Option
4
0.72
8.4
15
0.0020
0.12
Net Increase In Energy Consumption -
Indirect Dischargers
million kilotfatt-hQurs/vr
Subcategorv
Aluminum
Copper
Ferrous
Magnesium
Zinc
Option
1
0.59
2.2
n
0.0016
0.16
Option
2
0.63
2,5
11
0.0021
0.18
Option
V
0.88
2.9
14
0.0028
0.21
Option
H
1.1
3.4
15
0.0028
0.27
454
-------
Table VIII-12
INCREMENTAL INCREASE IN SOLID WASTE GENERATION
DUE TO APPLICATION OF MODEL TREATMENT TECHNOLOGY
Incremental Increase in Solid Waste Generation -
Direct Dischargers
(tons/year)
•r
Aluminum
Copper
Ferrous
Magnesium
Zinc
Subcategorv
Aluminum
Copper
Ferrous
Magnesium
Zinc
Current
Discharge
to Option
1
1,400
1,400
570,000
0.092
1,200
Incremental
Current
Discharge
to Option
1
10,000
250
480,000
1.6
5,900
Option
to
2-2
140
770
0.
1.
1 Option 2
to
j> Oj>tipji J3
9.5
68
240
0013 0.0005
7 1.5
Increase in Solid Waste Gene
Indirect Dischargers
(tons/jrearl
Option
to
Option
15
14
600
0.
5.
1 Option 2
to
2 Option 3
6.1
11
180
0079 0.0035
2 2.7
Option 3
to
Option H
22
40
210
0.0026
6.2
ration -
Option 3
to
Qptipn ^
32
25
280
0.018
13
455
-------
Table VIII-13
CONSUMPTIVE WATER LOSS DUE TO APPLICATION
OF HIGH RATE RECYCLE
(million gallons/year)
Subcategorv
Aluminum
Copper
Ferrous
Magnesium
Zinc
Consumptive
Vjfafrer Loss
Negligible
83
90
Negligible
1
Total
Subcategory?
Applied Flo^r
2,400
12,000
69,000
2.6
770
Water Loss
as Percentage
of Applied Flow
0
0.70
0.13
0
0,13
1
Estimated as 2 percent loss due to drift and evaporation in
those segments that require cooling towers.
'Based on applied flow of direct and indirect discharging plants,
456
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SECTION IX
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
INTRODUCTION
This section identifies model technologies, pollutants regulated,
and mass-based limitations attainable through the application of
the best practicable control technology currently available
(BPT).
The factors considered in identifying BPT include the total cost
of applying the technology in relation to the effluent reduction
benefits from such application, the age of equipment and
facilities involved, the manufacturing processes employed,
nonwater quality environmental impacts (including energy
requirements), and other factors the Administrator considers
appropriate. In general, the BPT level represents the average of
the best existing performances of plants of various ages, sizes,
processes, or other common characteristics. Where existing
performance is uniformly inadequate, BPT may be transferred from
a different subcategory or category. Limitations based on
transfer of technology are supported by a rationale concluding
that the technology is transferable, and a reasonable prediction
that it will be capable of achieving the prescribed effluent
limits. See Tanner' s Council of_ America v. Train, 540 F,2d 1188
(4th Cir. 1976). BPT includesinternal controls, such as
recycle, where such practices are common industry practice.
TECHNICAL APPROACH TO BPT
The objective of BPT effluent limitations is to reduce the total
quantity of pollutants discharged into surface waters. Because
plants could meet concentration-based limitations by dilution
rather than treatment, mass limitations have been developed for
the metal molding and casting industry. In order to establish
nationally-applicable effluent limitations guidelines, the mass
limitations were normalized by an appropriate production
normalizing parameter (PNP). As discussed in Section IV, the PNP
for the metal molding and casting category is generally tons of
metal poured. For the case of scrubber discharges, the PNP is
thousand standard cubic feet (1,000 SCF) of air flow through the
scrubber. For the case of ferrous wet sand reclamation, the PNP
is tons of sand reclaimed.
Pollutant discharge limitations for this category are written as
mass loadings, allowable mass of pollutant discharge per mass of
metal poured or sand reclaimed or volume of air flow through a
wet scrubber. Mass loadings were calculated for each process
segment within each subcategory. This calculation was made on a
segment-by-segment basis because plants in this category may
perform one or more operations in one or more subcategories.
457
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The pollutant discharge limitation for each operation was
calculated by multiplying the median production normalized
wastewater discharge flow {gal/ton or gal/1,000 SCF) for that
segment by the effluent concentration achievable by the BPT
treatment technology (mg/1).
In order to determine which pollutants are found in wastewaters
generated by the metal molding and casting industry, and thus
require regulation, EPA conducted a field sampling program. This
program and its results are described in Section V of this
document.
Oil and grease, suspended solids, priority organic and metal
pollutants, and total phenols are present in significant and
treatable concentrations in wastewaters generated by the metal
molding and casting operations. Although concentrations of the
specific priority organic and metal pollutants present will vary
from subcategory to subcategory, the same types of pollutants and
similar wastewater matrices are present in each subcategory.
Therefore/ one treatment technology with preliminary treatment,
where necessary, is an appropriate basis for BPT effluent
limitations for all subcategories.
Although BPT limitations apply only to plants which discharge
wastewater directly, direct and indirect dischargers have been
considered as a single group in making technical assessments of
data, reviewing manufacturing processes, and evaluating
wastewater treatment technology options. An examination of
plants and processes did not indicate any process differences
based on the type of discharge, whether it be direct or indirect.
Consequently, the calculation of the BPT regulatory flow included
normalized flows from both direct and indirect dischargers,
BPT OPTION SELECTION
The Agency evaluated several end-of-pipe and in-process
technologies to determine how suitable they are for controlling
the pollutants detected in the sampling program (see Section
VII). One of these treatment trains (Option 2) was selected as
BPT: high rate recycle, with treatment of recycle system
blowdown by oil skimming and lime precipitation and sedimentation
(L&S), For the case of aluminum and zinc die casting, treatment
is within the recycle loop, with recycle system blowdown
discharged directly. Treatment for some process segments also
includes emulsion breaking to remove emulsified lubricant oils
and chemical addition (potassium permanganate) to oxidize
phenolics and other organic compounds. This treatment will
remove toxic metal and organic pollutants, phenols, oil and
grease, and TSS. With the minor adjustments noted here and in
Section VII for individual processes, this technology will be
equally effective in treating wastewater from different generic
processes (e.g., die casting, melting furnace scrubber, etc.)
across subcategories.
458
-------
EPA considered Option 1 (recycle, simple settling) for the BPT
technology basis, but rejected it because these technologies are
not effective in removing dissolved metals and emulsified oils.
Dissolved metals and emulsified oils from die lubricants are a
substantial portion of the raw waste load,
High-rate recycle, oil skimming, emulsion breaking, and lime and
settle technologies are widely demonstrated in the metal molding
and casting category (see Tables VII-1 and VII-4), The
application and performance of this treatment train are discussed
in detail in Section VII.
Chemical oxidation using potassium permanganate is not presently
in use at full scale metal molding and casting treatment systems*
However, potassium permanganate oxidation has been demonstrated
in many other municipal and industrial wastewater treatment
applications for removal of phenolic and other organic compounds.
In addition, potassium permanganate oxidation has been shown to
be effective in reducing total phenol and other organic
concentrations in bench scale tests performed on metal molding
and casting wastewater. The results of these bench tests are
discussed in Section VII. The treatment effectiveness concentra
tions used to determine BPT mass limitations for total phenol are
based on mean performance at metal molding and casting plants
with recycle, oil skimming and/or emulsion breaking, and lime and
settle technology only. There are two reasons this technology
option includes potassium permanganate addition for some process
segments: first, to ensure that the chemical addition
requirements at plants with high raw waste loads have not been
underestimated; and, second, because some plants may need to
employ potassium permanganate to ensure that the lime and settle
treatment effectiveness concentrations will be met.
Treatment trains selected for each process segment are discussed
later in this section.
EPA did not promulgate BPT limitations for the magnesium
subcategory. As discussed later in this section, EPA concluded
that BPT effluent limitations are not economically achievable for
the magnesium subcategory.
REGULATED POLLUTANT PARAMETERS
The pollutants considered for regulation under BPT in each
subcategory and the reasons for their consideration are described
in Section VI. Pollutants were selected for regulation in the
metal molding and casting subcategories because of their frequent
presence at treatable concentrations in raw wastewaters. The
basic list of pollutants selected for regulation in each
subcategory has not changed since proposal. Those pollutants are
copper, lead, zinc, oil and grease, phenol, total suspended
solids, and pH. However, the list of pollutants selected for
regulation in each process segment in some cases varies slightly
from the lists published at proposal and in the March 20, 1984
notice of availability. Following publication of the March 20
459
-------
notice, the Agency reevaluated the raw waste load data for each
subcategory and process segment in response to public comment*
Consideration of the reevaluated data led the Agency to select
copper, lead, zinc, oil and grease, TSS and pH for regulation at
BPT in each process segment. In addition, phenol is regulated in
10 process segments where the average concentration of phenol is
at treatable levels. The reasons for selecting the above
pollutants for regulation at BPT is discussed below. Additional
details on pollutant selection by subcategory are found in
Section VI of this document and in Section 22.58 of the record.
Total suspended solids, in addition to being present at high
concentrations in raw wastewater from metal molding and casting
operations, is an important control parameter for metals removal
in chemical precipitation and settling treatment systems. Metals
are precipitated as particulate metal and as insoluble metal
hydroxides. Effective solids removal is required in order to
ensure reduced levels of regulated toxic metals in the treatment
system effluent. Therefore, total suspended solids are regulated
as a conventional pollutant to be removed from the wastewater
prior to discharge.
Oil and grease is regulated under BPT since a number of foundry
operations generate free and emulsified oily wastewater streams
which may be discharged. In addition, achieving a limitation on
the discharge of oil and grease helps ensure that the discharge
of toxic organic pollutants is controlled by incidentally
removing toxic organic pollutants. This phenomenon occurs
because of the preferential solubility of organics in oil, and is
discussed in detail in Section VII.
Total phenol is regulated in those process segments where the
average 'concentrations of total phenols are above treatable
levels. Total phenol is commonly regulated in existing permits
and gives an indication of levels of toxic phenolic and other
organic compounds.
The importance of pH control is documented in Section VII and its
importance in metals removal technology cannot be overemphasized.
Even small excursions from the optimum pH level can result in
less than optimum functioning of the treatment system and an
inability to achieve specified results. The optimum operating
level for removal of most metals is usually pH 8,8 to 9.3.
However, some metals require higher or lower pH for optimal
removal. To allow a reasonable operating margin and to preclude
the need for final pH adjustment, the effluent pH is specified to
be within the range of 7.0 to 10.
Copper, lead, and zinc are regulated because they are toxic metal
pollutants frequently found in wastewaters from this industry.
These metals are routinely controlled by existing discharge
permits and limitations on these metals will ensure effective
metals removal at the BPT level of treatment.
BPT FLOWS
460
-------
EPA used DCP's, recycle analysis, and other data for each process
segment within each subcategory to determine (!) the production
normalized applied flow rates/ (2) the specific recycle rates
achievable, and (3) the specific production normalized discharge
filows for each process segment.
First, the applied flow rates were analyzed to determine which
flow was to be used as part of the basis for BPT mass
limitations. The applied flow rates for each process segment are
shown in Tables V-l through V-29 {see Section V). For 25 of the
28 process segments, the median applied flow rate was selected as
the BPT applied flow rate. The median is a commonly accepted
measure of central tendency. Use of the median is very often
preferred to other such measures for a number of reasons. The
use of median water usage is a well established practice in
determining effluent limitations guidelines and is consistent
with the requirement that BPT limitations represent the average
of the best performers.
The BPT applied flow is based on the median of all available
data. Plants with existing applied flows above the median may
have to implement flow reduction methods to achieve the BPT
limitations. In most cases, this will involve improving
housekeeping practices, better maintenance to limit water
leakage, or reducing excess flow by turning down a flow valve.
See Section VII for a more thorough discussion of flow reduction
techniques. It is not believed that these modifications would
generate any significant costs for the plants.
High-rate recycle is widely demonstrated throughout the metal
molding and casting category. Therefore, the primary basis for
recycle rate selection was the highest practicable recycle rates
(i.e., lowest blowdown rates) demonstrated by plants in the
industry. In response to comments on the proposed regulations,
the Agency also developed a mathematical model of recycle system
water chemistry. The purposes of this analysis were to (!)
provide a greater technical understanding of the recycle systems,
(2) confirm the feasibility of high rate and complete recycle
systems or to identify water chemistry conditions which might
prevent systems from operating at complete recycle, and (3)
supplement industry data in identifying feasible ranges of
recycle rates for those processes and water chemistry conditions
for which complete recycle may not be feasible and for which
industry data and recycle experience are limited. The recycle
model also was used to determine the influence on achievable
recycle rates of make-up water quality, treatment system sludge
moisture content, and central treatment of combined process
wastewaters. Details on the basis and results of the recycle
model are presented in Section VII of this document.
In selecting recycle rates, the Agency considered recycle rates
demonstrated by plants in the same generic process segment across
subcategories. Generic processes are expected to exhibit the
same range of recycle properties (e.g., operating range of pH,
461
-------
scaling tendencies, need for chemical addition to maintain high-
rate recycle) and achievable recycle rates. Results of the
recycle model analysis confirmed these expectations. For these
reasons, the recycle rates selected for generic processes are
similar. Also, where necessary, data on recycle rates have been
consolidated by generic process across subcategories to ensure
that selected recycle rates are not based on limited or uncharac
teristic practices at a few plants.
In a few cases, the results of the recycle model analysis
indicated marginal differences from demonstrated recycle
practice. Specifically, in the ferrous subcategory, the melting
furnace scrubber, dust collection scrubber, and slag quench
process were found to be marginally sensitive to poor make-up
water quality. Accordingly, recycle rates have been reduced
below demonstrated rates to account for this sensitivity in these
three processes. Also, the Agency found there was no recycle
experience in the investment casting process. In this case, the
achievable recycle rate identified by the recycle model was
selected as the recycle rate for the investment casting process
in the aluminum, copper, and ferrous subcategories.
The recycle rates achievable for each process segment are
discussed by process later in this section.
Finally, the production normalized discharge flow was calculated
for each process segment using the following equation:
Discharge Flow = Applied Flow (1 - Recycle Rate/100).
Table IX-1 summarizes the BPT applied flow ratesr recycle rates,
and discharge rates for each process segment.
BPT EFFLUENT LIMITATIONS
The BPT mass limitations (mass of pollutant allowed to be
discharged per mass of metal poured, quantity of sand reclaimed,
or volume of wet scrubber air flow) are presented in Table IX-2.
These limitations were calculated for each regulated pollutant in
each process segment as follows: the BPT normalized flow for
each process segment (see Table IX-1) was multiplied by the one-
day maximum and by the maximum monthly average treatment
effectiveness concentrations (see Table VTI-12) corresponding to
the BPT technology option selected for each subcategory. As
explained in Section VII, the maximum monthly average treatment
effectiveness concentration is based on the average of 10 samples
over the period of a month.
The BFT limitations presented at proposal assumed that discharges
from metal molding and casting plants would always be on a
continuous basis. Information submitted in comments and
confirmed by EPA indicate that treatment is commonly done on a
batch basis with discharge on an intermittent basis.
To allow this practice to continue where plants find batch
462
-------
treatment to be an effective control technique, the final
regulations contain provisions that would allow metal molding and
casting plants to discharge on an intermittent basis provided
that they comply with annual average BPT limitations that are
equivalent to the BPT effluent limitations applicable to
continuous discharging plants. Plants are eligible for the
annual average limitations and standards where wastewaters are
stored for periods in excess of 24 hours to be treated on a batch
basis. NPDES permits established for these "noncontinuous"
discharging plants must contain concentration-based maximum day
and maximum for monthly average limitations established for
continuous discharging plants. BPT effluent limitations
applicable to intermittent discharging plants are shown in Table
IX-3.
BPT DEVELOPMENT BY SUBCATEGORY AND PROCESS SEGMENT
The remainder of this section describes the development of BPT
mass limitations for each subc£.tegory. The development of the
BPT regulatory flow for each process segment in each subcategory
is presented in detail. The pollutants regulated and the cost
and effluent reduction benefits of their regulation at BPT also
are listed. The methodology for calculating costs and benefits
is discussed in Section VIII.
Al.ujnimim. Subcategory
Option 2 (recycle, lime and settle} was selected as the
technology basis for BPT limitations in this subcategory. The
pollutants selected for limitations are pH, TSS, oil and grease,
copper, lead, and zinc. In addition, total phenol has been
detected in treatable concentrations in the aluminum die casting,
dust collection, and melting furnace scrubber process segments
and has been selected for regulation in those segments. The
applied flow rate, recycle rate, and model control technology for
each of the eight aluminum process segments are discussed below.
The total required investment cost for BPT model treatment
(beyond equipment in place) for aluminum casting plants is $3.1
million and the total annualized cost is $1.4 million {1985
dollars).
Total removal of toxic pollutants from current direct discharges
from aluminum casting plants would be 5,723 kg/yr (12,620
Ibs/yr). In addition, compliance with BPT will result in the
removal of 0,325 million kg/yr (0.716 million Ibs/yr) of total
(conventional, nonconventional, and toxic) pollutants.
Casting Cleaning
The model control technology is process water settling in a
settling tank followed by recycle. Acid is added to the recycle
system to control scaling. The blowdown from the recycle system
is treated in a lime and settle system which includes oil
skimming, lime and polymer addition, and settling.
463
-------
The flow bhat forms the basis of the BPT effluent limitations
(BPT flow) promulgated for aluminum casting cleaning is 24
gallons/ton of metal poured. The median applied flow rate of 480
gallons/ton was obtained from Table V-l. That shows three plants
reporting sufficient information to calculate an applied flow
rate. Plant 07280 has the median flow rate.
Two of the three plants in the metal molding and casting data
base that recycle casting cleaning process water recycle 95
percent or more of that water. The one plant in the metal
molding and casting data base that recycles aluminum casting
cleaning process water recycles 99 percent of thab water.
However, casting cleaning water generally carries a high
pollutant load and 99 percent recycle may not be attainable in
all cases. Based on demonstrated recycle practice for this
process across subcategories, the BPT recycle rate for the
aluminum casting cleaning segment is 95 percent.
Casting Quench
The model control technology is process water settling in a
settling tank followed by recycle. Acid is added to the recycle
system to control scale formation. The blowdown from the recycle
system is treated in a lime and settle system which includes oil
skimming, lime and polymer addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for aluminum casting quench is 2.9 gallons
per ton of metal poured. The median applied flow rate of 145
gallons per ton was obtained from Table V-2. That shows 23
plants reporting sufficient information to calculate an applied
flow rate. Plant 26767 has the median flow rate.
Eight of the 14 plants in the aluminum casting quench segment
that recycle aluminum casting quench process water recycle 98
percent or more of that water. Based on the water chemistry
model, EPA estimates that 100 percent recycle of aluminum casting
quench water is achievable if make-up waber of mean quality is
available? 98 percent recycle is achievable if make-up water of
poor quality is available. Based on demonstrated recycle
practice and confirmed as achievable by the water chemistry
model, the BPT recycle rate for the aluminum casting quench
segment is 98 percent.
Die Casting
The model control technology is treatment of the entire process
wastewater flow in a lime and settle system which includes
emulsion breaking, oil skimming, chemical oxidation by potassium
permanganate, lime and polymer addition, settling, followed by
recycle. Acid is added to the recycle system to control scale
formation. including the full measure of Option 2 treatment
inside the recycle loop ensures that water quality after
treatment is suitable for recycle.
464
-------
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for aluminum die casting is 2.07 gallons
per ton of metal poured. The median applied flow rate of 41,4
gallons per ton was obtained from Tables V-3 and V-27, They show
27 plants reporting sufficient information to calculate a die
casting applied flow rate. Plant 18139 has the median flow rate.
Plow data for aluminum and zinc die casting operations are
combined because these operations are very similar, and are often
performed at the same plant using the same or similar equipment.
Seven of the 11 plants in the aluminum and zinc die casting
segment that recycle die casting process water recycle 95 percent
or more of that water. Based on the water chemistry model, EPA
estimates that 100 percent recycle of aluminum die casting
process water is achievable using make-up water of either mean or
poor quality. Based on demonstrated recycle practice and
confirmed as achievable by the water chemistry model, the BPT
recycle rate for the aluminum die casting segment is 95 percent.
Dust Collection Scrubber
The model control technology is process water settling in a
settling tank followed by recycle. Acid is added to the recycle
system to control scale formation. The blowdown from the recycle
skimming, chemical oxidation by potassium permanganate, lime and
polymer addition, and settling. Following the February 15, 1985
notice of availability, EPA included chemical oxidation using
potassium permanganate in the model BPT basis for the aluminum
dust collection scrubber process segments. This was done to
ensure that the phenol limitations would be achievable even where
high levels of phenols would be present in the treatment system
influent.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for aluminum dust collection scrubber is
0.036 gallons per thousand standard cubic feet of air. The
median applied flow rate of 1,78 gallons per 1,000 SCF was
obtained from Table V-4. That shows nine plants reporting
sufficient information to calculate an applied flow rate. Plant
20063 has the median flow rate.
Seven of the 11 plants in the metal molding and casting data base
in nonferrous subcategories that recycle dust collection scrubber
water recycle 98 percent or more of that water. Based on the
water chemistry model, EPA estimates that 100 percent recycle of
aluminum dust collection scrubber water is achievable using make-
up water of either mean or poor quality. Based on demonstrated
recycle practice and confirmed as achievable by the water
chemistry model, the BPT recycle rate for the aluminum dust
collection scrubber segment is 98 percent.
465
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Grinding Scrubber
The model control technology is process water settling in a
settling tank followed by complete recycle. Acid is added to the
recycle system to control scale formation.
There is no BPT discharge flow allowance for aluminum grinding
scrubber wastewater. The median applied flow rate of 0.063
gallons/1,000 SCP was obtained from Table V-5. That shows three
plants reporting sufficient information to calculate an applied
flow rate. Plant 74992 has the median applied flow rate.
Two of the three plants in nonferrous subcategories that recycle
grinding scrubber water recycle 100 percent of that water. In
addition, five of the 12 plants in the metal molding and casting
data base that recycle ferrous grinding scrubber water recycle
100 percent of that water. Based on demonstrated recycle
practice, the BPT recycle rate for the aluminum grinding scrubber
segment is 100 percent.
Investment Casting
The model control technology is process water settling in a drag
tank followed by recycle. Caustic is added to the recycle system
to control corrosion. The blowdown from the recycle system is
treated in a lime and settle system which includes oil skimming,
lime and polymer addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for aluminum investment casting is 2,640
gallons per ton of metal poured. The median applied flow rate of
17,600 gallons per ton was obtained from Table V-6. That shows
four plants reporting sufficient information to calculate an
applied flow rate. Plants 05206 and 20063 have the median flow
rates. The median is based on the average of these two flows.
The reported flows for aluminum, copper, and ferrous investment
casting are combined because two of the four plants with
investment casting (plants 04704 and 01994) cast all three
metals.
There are no plants that recycle wastewater. However, based on
the water chemistry model, EPA estimates that 85 percent recycle
of aluminum investment casting process water is achievable using
make-up water of either mean or poor quality. Therefore, the BPT
recycle rate for the aluminum investment casting segment is 85
percent.
Melting Furnace Scrubber
The model control technology is process water settling in a
settling tank followed by recycle. Acid is added to the recycle
system to control scale formation. The blowdown from the recycle
system is treated in a lime and settle system which includes oil
skimming, chemical oxidation by potassium permanganate, lime and
polymer addition, and settling. Following the February 15, 1985
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notice of data availability, EPA included chemical oxidation
using potassium permanganate for the aluminum melting furnace
scrubber process segment. This was done to ensure that the
phenol limitations would be achievable even where high levels of
phenols would be present in the treatment system influent.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for aluminum melting furnace scrubber is
0.468 gallons per thousand standard cubic feet. The median
applied flow rate of 11.7 gallons per 1,000 SCF was obtained from
Table V-7. That shows four plants reporting sufficient
information to calculate an applied flow rate. Plants 17089 and
22121 have the median flow rate.
Eight of the 13 plants in the metal molding and casting data base
in nonferrous subcategories that recycle melting furnace scrubber
water recycle 95 percent or more of that water. Five of the 13
recycle 97 percent or more of the water. In addition, 51 of 85
plants in the metal molding and casting data base that recycle
ferrous melting furnace scrubber water recycle 96 percent or more
of that water. Based on the water chemistry model, EPA estimates
that 100 percent recycle of aluminum melting furnace scrubber
water is achievable if make-up water of mean quality is
available; 99.5 percent recycle is achievable if make-up water of
poor quality is available. Based on demonstrated recycle
practice and confirmed as achievable by the water chemistry
model, the BPT recycle rate for the aluminum melting furnace
scrubber segment is 96 percent.
Mold Cooling
The model control technology is process water settling in a
settling tank followed by recycle. Acid is added to the recycle
system to control scale formation. The blowdown from the recycle
system is treated in a lime and settle system which includes oil
skimming, lime and polymer addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for aluminum mold cooling is 92.5 gallons
per ton of metal poured. The median applied flow rate of 1,850
gallons per ton was obtained from Table V-8, That shows 15
plants reporting sufficient information to calculate an applied
flow rate. Plant 87599 has the median flow rate.
Fifteen of the 25 plants in the metal molding and casting data
base that recycle mold cooling water recycle 95 percent or more
of that water. Based on demonstrated recycle practice, the BPT
recycle rate for the aluminum mold cooling segment is 95 percent.
Copper Subcategory
Option 2 (recycle, lime and settle) was selected as the
technology basis for BPT limitations in this subcategory. The
pollutants selected for limitations are pH, TSS, oil and grease,
copper, leadt and zinc. In addition, total phenol has been
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detected in treatable concentrations in the copper dust
collection scrubber and melting furnace scrubber segments, and
has been selected for regulation in those segments. The applied
flow rate/ recycle rate/ and model control technology for each of
the seven copper process segments are discussed below.
The total required investment cost for BPT model treatment
(beyond equipment in place) for copper casting plants is $8.4
million and the total annualized cost is $3.7 million (1985
dollars).
Total removal of toxic pollutants from current direct discharges
from copper casting plants would be 70,050 kg/yr (154,500
Ibs/yr). In addition/ compliance with BPT will result in the
removal of 0.300 million kg/yr (0.660 million Ibs/yr) of total
(conventional/ nonconventional, and toxic) pollutants.
Casting Quench
The model control technology is process water settling in a
settling tank followed by recycle. Acid is added to the recycle
system to control scale formation. The recycle loop includes a
cooling tower for larger size plants to maintain a proper process
water temperature. The blowdown from the recycle system is
treated in a lime and settle system which includes oil skimming,
lime and polymer addition, and settling,
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for copper casting quench is 9.56 gallons
per ton of metal poured. The median applied flow rate of 478
gallons per ton was obtained from Table V-9. That shows 18
plants reporting sufficient information to calculate an applied
flow rate. The median flow is based on the average flow from
plants 25007 and 25009.
Four of the seven plants in the copper casting quench segment
that recycle copper casting quench water recycle 98 percent or
more of that water. Based on demonstrated recycle practice, the
BPT recycle rate for the copper casting quench segment is 98
percent.
Direct Chill Casting
The model control technology is process water settling in a
settling (drag) tank followed by recycle. Acid is added to the
recycle system to control scale formation. The recycle loop
includes a cooling tower to maintain proper process water
temperature. The blowdown from the recycle system is treated in
a lime and settle system which includes oil skimming, lime and
polymer addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for copper direct chill casting is 289
gallons per ton of metal poured. The median applied flow rate of
5,780 gallons per ton was obtained from Table V-1Q. That shows
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five plants reporting sufficient information to calculate an
applied flow rate. Plant 80029 has the median flow rate.
Five of the seven plants in the copper direct chill casting
segment that recycle copper casting quench water recycle 95
percent or more of that water. Based on the water chemistry
model, EPA estimates that 100 percent recycle of copper direct
chill casting water is achievable using make-up water of either
mean or poor quality. Baaed on demonstrated recycle practice and
confirmed as achievable by the water chemistry model, the BFT
recycle rate for the copper direct chill casting segment is 95
percent.
Dust Collection Scrubber
The model control technology is process water settling in a drag
tank followed by recycle. Acid is added to the recycle system to
control scale formation. The blowdown from the recycle system is
treated In a lime and settle system which includes oil skimming,
chemical oxidation by potassium permanganate, lime and polymer
addition, and settling. Following the February 15, 1985 notice
of data availability, EPA included chemical oxidation using
potassium permanganate for the copper dust collection scrubber
process segment. This was done to ensure that the phenol
limitations would be achievable even where high levels of phenols
would be present in the treatment system influent.
The flow that forms the basis ofc the BPT effluent limitations
(BPT flow) promulgated for the copper dust collection scrubber
process segment is 0.086 gallons per thousand standard cubic
feet. The median applied flow rate of 4.29 gallons per 1,000 SCF
was obtained from Table V-ll. That shows nine plants reporting
sufficient information to calculate an applied flow rate. Plant
38840 has the median flow rate.
Seven of the 11 plants in the metal molding and casting data base
in nonferrous subcategories that recycle dust collection scrubber
water recycle 98 percent or more of that water. Based on the
water chemistry model, EPA estimates that 100 percent recycle of
copper dust collection scrubber water is achievable if make-up
water of either mean or poor quality is available. Based on
demonstrated practice and confirmed as achievable by the water
chemistry model, the BPT recycle rate for the copper dust
collection scrubber segment is 98 percent.
Grinding Scrubber
The model control technology is process water settling in a
settling tank followed by complete recycle. Acid is added to the
recycle system to control scale formation.
There is no BPT discharge flow allowance for copper grinding
scrubber wastewater. The median applied flow rate of 0.111
gallons/1,000 SCF was obtained from Table V-12. That shows one
plant reporting sufficient information to calculate an applied
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flow rate. Plant 04851 has the median applied flow rate.
Two of the three plants in the metal molding and casting data
base in nonferrous subcategories that recycle grinding scrubber
water recycle 100 percent of that water. The one plant in the
data base that recycles copper grinding scrubber water recycles
100 percent of that water. Based on demonstrated recycle
practice, the BPT recycle rate for the copper grinding scrubber
segment is 100 percent.
Investment Casting
The model control technology is process water settling in a
settling tank followed by recycle. Caustic is added to the
recycle system to control corrosion. The blowdown from the
recycle system is treated in a lime and settle system which
includes oil skimming, lime and polymer addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for copper investment casting is 2,640
gallons per ton of metal poured. The median applied flow rate of
17,600 gallons per ton was obtained from Table V-6. That shows
four plants reporting sufficient information to calculate an
applied flow rate. Plants 05206 and 20063 have the median flow
rates. The median is based on the average of these two flows.
The reported flows for aluminum, copper, and ferrous investment
casting are combined because two of the four plants with
investment casting (plants 04704 and 01994) cast all three
metals.
Using the water chemistry model, it was shown that 85 percent
recycle of aluminum investment casting process water is
achievable. Copper investment casting process water should
exhibit the same recycle potential as aluminum investment casting
process water because the processes are essentially the same and
the wastewater characteristics are similar. Therefore, the BPT
recycle rate for the copper investment casting segment is 85
percent.
Melting Furnace Scrubber
The model control technology is process water settling in a
settling tank followed by recycle. Acid is added to the recycle
system to control scale formation. The blowdown from the recycle
system is treated in a lime and settle system which includes
chemical oxidation by potassium permanganate, oil skimming, lime
and polymer addition, and settling. Following the February 15,
1985 notice of data availability, EPA included chemical oxidation
using potassium permanganate in the model BPT basis for the
copper melting furnace scrubber process segment. This was done
to ensure that the phenol limitations would be achievable even
where high levels of phenols would be present in the treatment
system influent.
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The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for copper melting furnace scrubber is
0.282 gallons per thousand standard cubic feet. The median
applied flow rate of 7.04 gallons per 1,000 SCF was obtained from
Table v-13. That shows three plants reporting sufficient
information to calculate an applied flow rate. Plant 05934 has
the median flow rate.
Five of the 13 plants in the metal molding and casting data base
in nonferrous subcategories that recycle melting furnace scrubber
water recycle 96 percent or more of that water. In addition, 51
of 85 plants in the metal molding and casting data base that
recycle ferrous melting furnace scrubber water recycle 96 percent
or more of that water. Based on demonstrated recycle practice,
the BPT recycle rate for the copper melting furnace scrubber
segment is 96 percent.
Hold Cooling
The model control technology is process water settling in a
settling tank followed by recycle. Acid is added to the recycle
system to control scale formation. The recycle loop includes a
cooling tower to maintain proper process water temperatures. The
blowdown from the recycle system is treated in a lime and settle
system which includes oil skimming, lime and polymer addition,
and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for copper mold cooling is 122 gallons per
ton of metal poured. The median applied flow rate of 2,450
gallons per ton was obtained from Table V-14. That shows eight
plants reporting sufficient information to calculate an applied
flow rate. Plants 20017 and 08951 have the median flow rates.
The median flow is based on the average of these two plants*
flows.
Fifteen of the 25 plants in the metal molding and casting data
base that recycle mold cooling water recycle 95 percent or more
of that water. Based on the water chemistry model, EPA estimates
that 100 percent recycle of copper mold cooling water is
achievable if make-up water of mean quality is available? 99,5
percent recycle is achievable if make-up water of poor quality is
available. Based on demonstrated recycle practice and confirmed
as achievable using the water chemistry model, the BPT recycle
rate for the copper mold cooling segment is 95 percent.
Ferrous Subcategory
Option 2 (recycle, lime and settle) was selected as the
technology basis for BPT limitations in this subcategory. The
pollutants selected for limitations are pH, TSS, oil and grease,
copper, lead, and zinc. In addition, total phenols have been
detected in treatable concentrations in the ferrous dust
collection scrubber, melting furnace scrubber, and wet sand
reclamation segments, and has been selected for regulation in
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those segments. The applied flow rate, recycle rate, and model
control technology for each of the nine ferrous process segments
are discussed below«
The total required investment cost for BPT model treatment
(beyond equipment in place) for ferrous casting plants is $27.9
million and the total annualized cost is $12.2 million (1985
dollars).
Total removal of toxic pollutants from current direct discharges
from ferrous casting plants would be 731,100 kg/yr (1,612,000
Ibs/yr). In addition, compliance with BPT will result in the
removal of 65.3 million kg/yr {144 million Ibs/yr) of total
(conventional, nonconventional, and toxic) pollutants.
Casting Cleaning
The model control technology is process water settling in a
settling tank followed by recycle. The blowdown from the recycle
system is treated in a lime and settle system which includes oil
skimming, lime and polymer addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for ferrous casting cleaning is 10.7
gallons per ton of metal poured. The median applied flow rate of
213 gallons per ton was obtained from Table V-15. That shows 15
plants reporting sufficient information to calculate an applied
flow rate. Plant 20699 has the median flow rate.
Two of the three plants in the ferrous and nonferrous
subcategories in the metal molding and casting data base that
recycle casting cleaning process water recycle 95 percent or more
of that water. Based on demonstrated recycle practice, the BPT
recycle rate for the ferrous casting cleaning segment is 95
percent,
Casting Quench
The model control technology is process water settling in a
settling tank followed by recycle. Acid is added to the recycle
system to control scale formation. The recycle loop includes a
cooling tower for larger size plants to maintain a proper process
water temperature. The blowdown from the recycle system is
treated in a lime and settle system which includes oil skimming,
lime and polymer addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for ferrous casting quench is 11.4 gallons
per ton of metal poured. The median applied flow rate of 571
gallons per ton was obtained from Table V-16. That shows 4S
plants reporting sufficient information to calculate an applied
flow rate. Plants 103S1 and 07472 have the median flow rates,
The median is based on the average of the flows of these two
plants.
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Seventeen of the 24 plants that recycle ferrous casting quench
water recycle 98 percent or more of that water. Based on the
water chemistry model, EPA estimates that 100 percent recycle of
combined ferrous casting quench and ferrous mold cooling water is
achievable if make-up water of mean quality is available; 99.5
percent recycle is achievable if make-up water of poor quality is
available. Based on demonstrated recycle practice, and confirmed
as achievable using the water chemistry model, the BPT recycle
rate for the ferrous casting quench segment is 98 percent.
Dust Collection Scrubber
The model control technology is process water settling in a drag
tank followed by recycle. Acid is added to the recycle system to
control scale formation. The blowdown from the recycle system is
treated in a lime and settle system which includes oil skimming,
chemical oxidation by potassium permanganate, lime and polymer
addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for ferrous dust collection scrubber is
0.09 gallons per thousand standard cubic feet. The median
applied flow rate of 3.0 gallons per 1,000 SCF was obtained from
Table V-17. That shows 153 plants with a total of 1,031
scrubbers reporting sufficient information to calculate an
applied flow rate. Plants 01644, 01834, 04073, 04621, 09148,
11964, 12203, 14069, 14809, 17348, 19347, 27743, and 38842 have
the median flow rate.
Seventy-seven of the 126 plants in the metal molding and casting
data base that recycle ferrous dust collection scrubber water
recycle 98 percent or more of that water. Based on the water
chemistry model, EPA estimates that 97,5 percent recycle of
ferrous dust collection scrubber water is achievable if make-up
water of mean quality is available; 97 percent recycle is
achievable if make-up water of poor quality is available. In
this case, the model predicted recycle rate based on mean make-up
water quality is lower than the rate demonstrated as achievable.
The Agency believes that this shows that the recycle model
analysis predicts lower recycle rates than actually are
achievable for this segment. In addition, in the ferrous dust
collection scrubber segment, the recycle model has shown that if
poor quality make-up waters are used, marginally lower attainable
recycle rates are anticipated than if mean quality make-up waters
are used. For these reasons, EPA did not base the selection of
the BPT recycle rate on the results of the model for worst make-
up water quality. Rather, the Agency calculated the difference
between recycle rates based on average make-up water quality and
worst make-up water quality (97.5 percent less 97.0 percent, or
0.5 percent rounded to 1.0 percent), and reduced the demonstrated
recycle rate of 98 percent by that amount. Thus, the recycle
rate selected was 97 percent. Additionally, it has been found
through the use of the recycle model that the marginal increase
in blowdown rate, necessary to account for make-up water quality,
is adequate to allow facilities with central treatment of
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combined wastewaters (including ferrous dust collection scrubber
water) to achieve separate stream recycle rates on a flow-
weighted basis.
Grinding Scrubber
The model control technology is process water settling in a
settling tank, followed by complete recycle. Acid is added to
the recycle system to control scale formation.
There is no BPT discharge flow allowance for ferrous grinding
scrubber. The median applied flow rate of 3.17 gallons/1,000 SCF
was obtained from Table V-18. That shows 27 plants reporting
sufficient information to calculate an applied flow rate. The
median flow rate is based on the average of the flows reported by
plants 16612 and 04621.
Five of the 11 plants that recycle ferrous grinding scrubber
water recycle 100 percent of that water. Based on demonstrated
recycle practice, the BPT recycle rate for the ferrous grinding
scrubber segment is 100 percent.
Investment Casting
The model control technology is process water settling in a
settling tank followed by recycle. Caustic is added to the
recycle system to control corrosion. The blowdown from the
recycle system is treated in a lime and settle system which
•includes oil skimming, lime and polymer addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for ferrous investment casting is 2,640
gallons per ton of metal poured. The median applied flow rate of
17,600 gallons per ton was obtained from Table V-6, That shows
four plants reporting sufficient information to calculate an
applied flow rate. Plants 05206 and 20063 have the median flow
rates. The median is based on the average of these two flows.
The reported flows for aluminum, copper, and ferrous investment
casting are combined because two of the four plants with
investment casting (plants 04704 and 01994) cast all three
metals.
Based on the water chemistry model, EPA estimates that 85 percent
recycle of aluminum investment casting process water is
achievable. Ferrous investment casting process water should
exhibit the same recycle potential as aluminum investment casting
process water because the processes are essentially the same and
the wastewater characteristics are similar. Therefore, the BPT
recycle rate for the ferrous investment casting segment is 85
percent.
Melting Furnace Scrubber
The model control technology is process water settling in a drag
tank followed fay recycle. Acid is added to the recycle loop to
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control scale formation. The blowdown from the recycle system is
treated in a lime and settle system which includes oil skimming,
chemical oxidation by potassium permanganate, lime and polymer
addition, and settling. Following the February 15, 1985 notice
of data availability, EPA included chemical oxidation using
potassium permanganate for the ferrous melting furnace scrubber
process segment. This was done to ensure that the phenol
limitations would be achievable even where high levels of phenols
would be present in the treatment system influent.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for ferrous melting furnace scrubber is
0.42 gallons per thousand standard cubic feet. The median
applied flow rate of 10.5 gallons per 1,000 SCF was obtained from
Table V-19, That shows 86 scrubbers for which sufficient
information to calculate an applied flow rate is available.
Plants 14254, 16612, and 08496 have the median flow rates. The
median is based on the average of the flows at plants 14254 and
either plant 16612 or 08496, since they have identical flows.
Forty-seven of the 85 plants in the metal molding and casting
data base that recycle ferrous melting furnace scrubber water
recycle 98 percent or more of that water. In the March 20, 1984
notice of availability, EPA indicated that the probable
regulatory recycle rate being considered for the ferrous melting
furnace scrubber segment was 98 percent recycle. Based on the
water chemistry model, EPA estimates that 95 percent recycle of
ferrous melting furnace scrubber water is achievable if make-up
water of mean quality is available; 93 percent recycle is
achievable if make-up water of poor quality is available. In
this case, the model predicted recycle rate based on mean make-up
water quality is lower than the rate demonstrated as achievable.
The Agency believes that this shows that the recycle model
analysis predicts lower recycle rates than actually are
achievable for this segment. In addition, in this segment the
recycle model has shown that if poor quality make-up waters are
used, marginally lower attainable recycle rates are anticipated
than if mean quality make-up waters are used. For these reasons,
EPA did not select recycle rates that are exactly as identified
by the model for worst make-up water quality. Rather, the Agency
has determined that the BPT recycle rate should be 96 percent.
This rate approximates the difference between recycle rates based
on average make-up water quality and worst make-up water quality
(2 percent), applied to reduce the demonstrated recycle rate (98
percent). Additionally, it has been found through use of the
recycle model that the marginal increase in blowdown rate,
necessary to account for make-up water quality, is adequate to
allow facilities with central treatment of combined wastewaters
(including ferrous melting furnace scrubber water) to achieve
separate stream recycle rates on a flow-weighted basis.
Mold Cooling
The model control technology is process water settling in a drag
tank followed by recycle. Acid is added to the recycle system to
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control scale formation. In addition, the recycle loop includes
a cooling tower to maintain proper process water temperatures.
The blowdown from the recycle system is treated in a lime and
settle system which includes oil skimming, lime and polymer
addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for ferrous mold cooling is 35.4 gallons
per ton of metal poured. The median applied flow rate of 707
gallons per ton was obtained from Table V-20. That shows 10
plants reporting sufficient information to calculate an applied
flow rate. Plants 17746 and 14069 have the median flow rates.
The median is based on the average flow of those two plants.
Fifteen of the 25 plants in the ferrous and nonferrous
subcategories in the metal molding and casting data base that
recycle mold cooling water recycle 95 percent or more of that
water. Based on the water chemistry model, EPA estimates that
100 percent recycle of combined ferrous mold cooling and ferrous
casting quench water is achievable if make-up water of mean
quality is available; 99.5 percent recycle is achievable if make-
up water of poor quality is available. Based on demonstrated
recycle practice, and confirmed as achievable using the water
chemistry model, the BPT recycle rate for the ferrous mold
cooling segment is 95 percent.
Slag Quench
The model control technology is process water setting in a
settling tank followed by recycle. Acid is added to the recycle
system to control scale formation. The blowdown from the recycle
system is treated in a lime and settle system which includes oil
skimming, lime and polymer addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for ferrous slag quench is 43.6 gallons
per ton of metal poured. The median applied flow rate of 727
gallons per ton was obtained from Table V-21. That shows 79
plants reporting sufficient information to calculate an applied
flow rate. Plant 16666 has the median flow rate.
Twenty-eight of 52 plants in the metal molding and casting data
base that recycle ferrous slag quench water recycle 95 percent or
more of that water. In the March 20, 1984 notice of
availability, EPA indicated that the probable regulatory recycle
rate being considered for the ferrous slag quench segment was 98
percent recycle. Based on the water chemistry model, EPA
estimates that 93 percent recycle of ferrous slag quench process
water is achievable if make-up water of mean quality is
available; 92 percent recycle is achievable if make-up water of
poor quality is available. In this case, the model predicted
recycle rate based on mean make-up water quality is lower than
the rate demonstrated as achievable. The Agency believes that
this shows that the recycle model analysis predicts lower recycle
rates than actually are achievable for this segment. In
addition? in this segment the recycle model has shown that if
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poor quality make-up waters are used, marginally lower attainable
recycle rates are anticipated than if mean quality make-up waters
are used. For these reasons, EPA did not select recycle rates
that are exactly as identified by the model for worst make-up
water quality. Rather, the Agency has determined that the BPT
recycle rate should be 94 percent. This rate approximates the
difference between recycle rates based on average make-up water
quality and worst make-up water quality (1 percent), applied to
reduce the demonstrated recycle rate (95 percent). Additionally,
it has been found through use of the recycle model that the
marginal increase in blowdown rate, necessary to account for
make-up water quality, is adequate to allow facilities with
central treatment of combined wastewaters (including ferrous slag
quench water) to achieve separate stream recycle rates on a flow-
weighted basis. Alternatively, plants with this process
wastewater may elect to segregate this stream so that the silica
scaling tendencies of the slag quench water do not interfere with
recycle of other process wastewater streams.
Wet Sand Reclamation
The model control technology is process water settling in a drag
tank followed by recycle. Acid is added to the recycle system to
control scale formation. The blowdown from the recycle system is
treated in a lime and settle system which includes oil skimming,
chemical oxidation by potassium permanganate, lime and polymer
addition, and settling.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for ferrous wet sand reclamation is 179
gallons per ton of sand reclaimed. The median applied flow rate
of 895 gallons per ton was obtained from Table V-22. That table
shows 14 plants reporting sufficient information to calculate an
applied flow rate. Plants 80770 and 51473 have the median flow
rates. The median is based on the average flow from those two
plants.
Three of the six plants that recycle ferrous wet sand reclamation
water recycle SO percent or more of that water. Based on the
water chemistry model, EPA estimates that the achievable recycle
rate of ferrous wet sand reclamation water varies from 97 to 97,5
percent, depending on make-up water quality. Based on
demonstrated recycle practice and confirmed as achievable by the
water chemistry model, the BPT recycle rate for the ferrous wet
sand reclamation segment is 80 percent.
Subcategory
EPA has not promulgated categorical BPT effluent limitations for
the magnesium subcategory. EPA has determined that the BPT
options considered for the magnesium subcategory are not
economically achievable for the subcategory as a whole. One of
two plants were projected to close if even the most basic of
treatment were used as the basis of BPT.
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Zinc Subcategory
Option 2 (recycle, lime and settle) was selected as the
technology basis for BPT limitations in this subcategory. The
pollutants selected for limitations are pH, TSS, oil and grease,
copper, lead, and zinc. In addition, total phenol has been
detected in treatable concentrations in the zinc die casting and
melting furnace scrubber segments, and has been selected for
regulation in those segments. The applied flow rate, recycle
rate, and model control technology for each of the four zinc
process segments are discussed below.
The total required investment cost for BPT model treatment
(beyond equipment in place) for zinc casting plants is $0.20
million and the total annualized cost is $0.13 million (1985
dollars).
Total removal of toxic pollutants from current direct discharges
from ferrous casting plants would be 2,166 kg/yr {4,776 Ibs/yr).
In addition, compliance with BPT will result in the removal of
0.221 million kg/yr {0.487 million Ibs/yr) of total
(conventional, nonconventional, and toxic) pollutants,
Casting Quench
The model control technology is process water settling in a
settling tank followed by recycle. Acid is added to the recycle
system to control scale formation. The blowdown from the recycle
system is treated in a lime and settle system which includes oil
skimming, lime and polymer addition, and settling.
The flow that forms the basis of the BPT effluent limitations
{BPT flow) promulgated for zinc casting quench is 10.7 gallons
per ton of metal poured. The median applied flow rate of 533
gallons per ton was obtained from Table V-26. That shows 21
plants reporting sufficient information to calculate an applied
flow rabe. Plant 05091 has the median flow rate.
Fourteen of the 30 plants in the metal molding and casting data
base in nonferrous subcategories that recycle casting quench
process water recycle 98 percent or more of that water.
Additionally, 17 of the 24 plants in the ferrous subcategory that
recycle casting quench water recycle 98 percent or more of that
water. Based on the water chemistry model, EPA estimates that
97.5 percent recycle of zinc casting quench water is achievable
when make-up water of mean quality is available and 97 percent
recycle is achievable when make-up water of poor quality is
available indicating that high rate recycle is supportable.
Based on demonstrated recycle practice in both ferrous and
nonferrous casting quench operations, the BPT recycle rate for
the zinc casting quench segment is 98 percent.
Die Casting
The model control technology is treatment of the entire process
478
-------
wastewater flow in a lime and settle system which includes
emulsion breaking, oil skimming, chemical oxidation by potassium
permanganate, lime and polymer addition, settling, followed by
recycle. Acid is added to the recycle system to control scale
formation. Including the full measure of Option 2 treatment
inside the recycle loop ensures that water quality after
treatment is suitable for recycle.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for zinc die casting is 2.07 gallons per
ton of metal poured. The median applied flow rate of 41.4
gallons per ton was obtained from Tables V-3 and V-27. They show
27 plants reporting sufficient information to calculate a die
casting applied flow rate. Plant 18139 has the median flow rate.
Flow data from aluminum and zinc die casting operations are
combined because these operations are very similar, and are often
performed at the same plant using the same or similar equipment.
As stated above, during plant visits and sampling episodes, and
upon evaluating industry questionnaire responses, EPA has
observed that aluminum and zinc are often die cast in the same
plant and that aluminum and zinc die casting operations may share
a centralized recycle system. Because of the similarity between
aluminum and zinc die casting, and the wastewater these
operations generate, EPA has concluded that the recycle rate used
as part of the basis for final regulations for these two
operations should be the same. Across the aggregate of all
aluminum and zinc die casting operations in the metal molding and
casting data base, seven out of 11 plants that recycle die
casting process water recycle 95 percent or more of that water.
Based on the water chemistry model, EPA estimates that the
achievable recycle rate of zinc die casting process water varies
between 98 and 99 percent depending on available make-up water
quality. Based on demonstrated recycle practice and confirmed as
achievable using the water chemistry model, the BPT recycle rate
for the zinc die casting segment is 95 percent.
Melting Furnace Scrubber
The model control technology is process water settling in a drag
tank followed by recycle. Acid is added to the recycle system to
control scale formation. The blowdown from the recycle system is
treated in a lime and settle system which includes oil skimming,
chemical oxidation by potassium permanganate, lime and polymer
addition, and settling. Following the February 15, 1985 notice
of data availability, EPA included chemical oxidation using
potassium permanganate in the model BPT basis for the zinc
melting furnace scrubber process segment. This was done to
ensure that the phenol limitations would be achievable even where
high levels of phenols would be present in the treatment system
influent.
The flow that forms the basis of the BPT effluent limitations
(BPT flow) promulgated for zinc melting furnace scrubber is 0.243
gallons per thousand standard cubic feet. The median applied
479
-------
flow rate of 6.07 gallons per 1,000 SCF was obtained from Tables
V-7, V-13, and V-28, They show 27 plants reporting sufficient
information to calculate an applied flow rate. Plant 18139 has
the median flow rate. Aluminum, copper, and zinc melting furnace
scrubber data were combined to form the data for determining the
zinc melting furnace scrubber applied flow rate. This was done
because EPA did not believe that zinc melting furnace scrubbers
could achieve a much lower applied flow rate than aluminum (11.7
gal/1,000 SCF) and copper scrubbers (4.29 gal/1,000 SCF), as the
zinc data alone (0.385 gal/1,000 SCF) seem to indicate.
Four of the seven plants in the metal molding and casting data
base that recycle zinc melting furnace scrubber water recycle 96
percent or more of the water. Based on the water chemistry
model, EPA estimates that 100 percent recycle of zinc melting
furnace scrubber water is achievable if make-up water of mean
quality is available; 99.5 percent recycle is achievable if make-
up water of poor quality is available. Based on demonstrated
recycle practice and confirmed as achievable using the water
chemistry model, the BPT recycle rate for the zinc die casting
segment is 96 percent.
Mold Cooling
The model control technology is process water settling in a
settling tank followed by recycle. Acid is added to the recycle
system to control scale formation. In addition, cooling towers
are included in the recycle loop to maintain a proper process
water temperature. The blowdown from the recycle system is
treated in a lime and settle system which includes oil skimming,
lime and polymer addition, and settling.
The flow that forms the basis of BPT effluent limitations (BPT
flow) promulgated for zinc mold cooling is 94.5 gallons per ton
of metal poured. The median applied flow rate of 1,890 gallons
per ton was obtained from Table V-29. That table shows seven
plants reporting sufficient information to calculate an applied
flow rate. Plant 10640 has the median flow rate.
Fifteen of the 25 plants in the metal molding and casting data
base that recycle mold cooling water recycle 95 percent or more
of that water. Based on demonstrated recycle practice, the BPT
recycle rate for the zinc mold cooling segment is 95 percent.
NON-WATER QUALITY ASPECTS OF BPT
The following are the nonwater quality environmental impacts
(including energy requirements) associated with the BPT effluent
limitations guidelines.
Air Pollution
Imposition of BPT will not create any substantial air pollution
problems. Minor very localized air pollution emissions currently
exist in the ferrous casting subcategory where wastewaters are
480
-------
used to quench the hot slag generated in the melting process.
Also, water vapor containing some particulate matter is released
from the cooling tower systems used in the casting quench and
mold cooling process segments. However, none of thfse conditions
currently are considered significant and no significant future
impacts are expected as the result of these regulations,
Solid Waste
EPA estimates that application of the best practicable technology
currently available will increase the quantity of solid wastes
that must be landfilled by plants in the metal molding and
casting category by about 522,000 kkg (575,000 tons) per year
beyond current levels. Of that amount, 573,000 tons per year is
sludge and If900 tons per year is oily waste. The Agency
examined the solid wastes that would be generated by metal
molding and casting processes using the model treatment
technologies and has concluded that they are not hazardous under
Section 3001 of the Resource Conservation and Recovery Act
(RCRA).
Consumptive Water Loss
Compliance with the BPT effluent limitations guidelines is not
expected to result in any significant incremental consumptive
water loss compared to metal molding and casting plants current
water usage.
Energy Requirements
EPA estimates that compliance with the BPT effluent limitations
guidelines will result in a total electrical energy consumption
of 19 x 10° kilowatt-hours per year. This is equivalent to an
increase of about 0.06 percent over the 31,3 x 10* kilowatt-hours
used in 1978 for production purposes.
481
-------
Table IX-1
APPLIED FLOW RATES, RATES, AND DISCHARGE RATES THAT FORM THE BASIS OF BPT
Suhcategory/Froeesa
Aluminum
Casting Cleaning
Casting Quench
Die Casting
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace Scrubber
Hold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting furnace Scrubber
Mold Cooling
Ferrous
Casting Cleaning
Casting Quench
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace Scrubber
Production
Normalized
ADD!ted Flou Rate
480 gal/ton
145 gal/ton
41.4 gal/ton
1.78 gal/1,000 SCF
0.063 gal/1,000 SCF
If.fiOO gal/ton
11,7 gal/1,000 SCF
1,850 gal/ton
178 gal/ton
5,780 gal/ton
4.29 gal/1,000 SCF
0.111 gal/1,000 SCF
17,600 gal/ton
7.04 gal/1,000 SCF
1,450 gal/ton
213 gal/ton
571 gal/ton
3.0 gal/1,000 SCF
3.17 gal/1,000 SCF
17,600 gal/ton
10.5 gal/1,000 SCF
Production
Normalizing Recycle
Parameter Hate
ton of metal poured 95$
ton of metal poured 98$
ton of metal poured 95$
1,000 SCF of air 98$
flow through the
scrubber
1,000 SCF of air 100$
flow through the
scrubber
ton of metal poured 85$
1,000 SCF of air 96$
flow through the
scrubber
ton of metal poured 95$
ton of metal poyred f8$
ton of metal poured 95%
1,000 SCr of air 98$
flow through the
scrubber
1,000 SCF of air 100$
flow through the
scrubber
ton of metal poured 85$
1,000 SCF of air 96$
flow through the
scrubber
ton of metal poured 95$
ton of metal poured 95$
ton of metal poured 98$
1,000 SCF of air 57$
flow through the
scrubber
1,000 SCF of air 100$
flow through the
scrubber
ton of metal poured 85$
1,000 SCF of air 96$
flow through the
scrubber
Production
Normalized
Discharge Flow*
24.0 gal/ton
2.90 gel/ton
2.0? gal/ton
0.036 gal/1,000
SCF
0
2,640 gal/ton
0.468 gal/1,000
SCF
92-5 gal/ton
9.56 gal/ton
289 gal/ton
0,086 gal/1,000
SCF
2,610 gal/ton
0,282 gal/1,000
iCF
122 gal/ton
10.7 gal/ton
11.4 gal/ton
0.090 gal/1,000
SCF
2,640 gal/ton
0.420 gal/1,000
SCF
-------
Table IX-1 (Continued)
APPLIED FLOW RATES, RECYCLE RATES, AND DISCHARGE RATES THAT FORM THE BASIS OF BPT
<*»
CD
GJ
Ferrous (Cont . )
Hold Cooling
Slag Quench
Wat Sand Reclamation
Zinc
Casting Quench
Die Casting
Welting Furnace Scrubber
Hold Cooling
Production
Normalized
Applied Flon Bate
707 gal/ton
727 gal/ton
895 gal/ton
533 gal/ton
41.tt gal/ton
6.07 gal/1,000 SCF
1,890 gal/ton
Production
Normalizing Recycle
Parameter __Balfi
ton of metal poured 951
ton or metal poured 94J
ton of sand reclaimed 80I
ton of netal poured 98%
ton of metel poured 95*
1,000 SCF of air 96*
flow through the
scrubber
ton of octal poured 951
Production
Normalized
Discharge
35.t gal/ton
•13,6 gal/ton
179 gil/ton
10,7 gal/ton
2.07 gal/ton
0.2*3 gal/1,000
SCF
94.5 gal/ton
-------
TABLE IX-2
BPT LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
TSS
Oil & Grease Phenols{l) _p_°_PR?_r_ Lead Zinc
Subcategory and
Process Segment
Aluminum
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
Direct Chill
Casti ng
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
30-Day
Max.
1.50
.182
.13
4.51
165
58.6
5.79
0.598
18.1
10,8
165
35.3
7.63
Daily
Max.
3.80
.46
.33
11.4
419
148
14.7
1.52
45.8
27.3
419
89.4
19.3
30- Day
Max.
1.0
.121
.0864
3.0
110
39.1
3.86
0.399
12.1
7.18
110
23,5
5.09
Daily
Max.
3.0
.363
.259
9.01
330
117
11.6
1.2
36.2
21.5
330
70.6
15.3
30- Day
Max.
(3)
(3)
.0026
.09
•i _
PiU
{3}
1.17
(3)
(3)
(3)
0,215
Wfj
{3}
0.706
(3)
Daily 30- Day
Max . Max .
(3) .0421
(3) ,0051
.0074 .0036
.258 .126
Discharge of Pol
(3) 4.63
3.36 1.64
(3) .162
(3) .168
(3) 0.506
0.617 0.301
Discharge of Pol
(3) 4.63
2.02 0.988
{3} 0.214
Daily
Max.
.0771
,0093
.0066
.231
Tut ants
8.48
3.01
.297
.0307
0.928
0.553
lutants
8.48
1.81
0.392
30-Day
Max.
.039
.0047
.0034
.117
4.3
1.52
.151
.0156
0.47
0.28
4.3
0.918
0,199
Daily
Max.
.0791
.0096
,0068
,237
8.7
3.09
.305
.0315
0.952
0.567
8.7
1.86
0,402
30- Day
Max,
,0431
.0052
.0037
.129
4.74
1.68
.166
.0171
0.518
0,309
4.74
1.01
0.219
Daily
Max. pH
.114 {2}
.0138 (2)
.0098 (2)
.343 (2)
12.6 (2)
4.45 (2)
.44 (2)
.0455(2)
(2)
1.37
0.818 (2)
12.6 (2)
2.68 (2)
0.58 (2)
* All limitations are in units of kg/1000 kkg fib per million 1b) of metal poured except for the Wet Sand
Reclamation, Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter
two process segments, the limitations are in units of kg/62.3 million Sm3 (tb per billion SCF) of air scrubbed;
in the case of the former process segment, the limitations are in units of kg/1000 kkg (1b per million 1b) of
sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at BPT for this process segment.
-------
Subcategory and
Process Segment
TABLE IX-2 (Continued)
BPT LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
TSS
30-Day ~Daily
Max. Max.
Oil 8
30-Day
Max.
Grease
Daily
Max.
Phenol s(l)
30-Day
Max.
Daily
Max.
Copper
30- Day Daily
Max. Max.
Lead
30-Day Daily
Max, Max,
Zi
30- Day
Max.
nc
"Daily
Max.
PH
Ji
CO
Ferrous
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
0.
0.
11.
165
52.
2.
2.
11.
67
713
3
fi
22
73
2
1
1
28
419
133
5
6
28
.7
.81
.5
.61
.91
.4
0,446
0.476
7
110
35
1
1
7
,51
.48
.82
.47
1
1
22
330
105
4
5
22
.34 .
.43
.5
.43
.46
.4
(3)
(3)
0.225
Wn
iiU
(3)
1.05
(3}
(3)
0.224
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Mold Cooling
0.67
0.13
30.4
5.91
1.7
.328
77.1
15
0.446
0.0864
20.3
3.94
60.8
11.8
0.608
(3)
(3)
(3)
0.0071
0.0076
0.656 0,12
scharge of Poll
(3) 1.76
3.01
(3}
(3)
0
0
0
.561
,0236
.029}
0.
0.
0.
ut
3
1
0
0
0129 0.
0138 0.
218 (
ants--
.19
.02
.0428
.0527
3.
4
1
0
0
0174
0185
293
.3
.37
.0576
.0709
0.0353
0.0376
0.593
8.
2.
0.
0.
7
77
117
144
0.025
0.0266
0.421
6.17
1.96
0.0827
Q.in2
0.
0.
1.
16
5
0
0
0556
0699
1
.2
.15
.217
.267
1.34 {3}
0.259 0.0026
0.642 0.12
(3) 0.0187
0.0074 0.0036
0.217 0.291 0.59 0.418 1.1
0.0344 0.0174
0.0066 0.0034
0.0353 0.0192
0.0068 0.0037
1.74
(3)
0,852
0.166
1.56
0.304
0,791
D.154
1.6
0.311
0,872
0.17
0.0509
0.0098
2.31
0.449
(2)
(2)
(2)
(2)
(2)
{2}
(2}
(2)
(2)
(2)
(2}
* All limitations are in units of kg/1000 kkg (lb per million Ib) of metal poured except for the Wet Sand
Reclamation, Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter
two process segments, the limitations are in units of kg/62.3 million Sm3 (Ib per billion SCF) of air scrubbed;
in the case of the former process segment, the limitations are in units of kg/1000 kkg (Ib per million lb) of
santl reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times
(3) Not regulated at BPT for this process segment.
-------
TABLE IX-3
BPT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
00
Suhcategory and
Process Segment
TSS
30-Day " Daily
Max. Max.
01_1_S Greasy
30-Day * Daily
Max. Hax.
PJienoJsJ_lJ_
30-DayDaily
Hax, Max.
Aluminum
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
15(12/x)
15(1. 45/x)
15(1. 04/x)
15{.D36/y)
15(1320/x)
15(. 468/y)
15(46. 3/x)
15(4.8/x)
15(145/x)
15{.086/y)
15{1320/x)
15(.282/y)
15(61/x)
38(1 2/x)
38(1. 45/x)
38(1. 04/x)
38f.036/y)
38{1320/x)
38{ .468/y)
38(46. 3/x)
38(4. 8/x)
38{l45/x)
38{ .086/y)
38(1320/x)
38{.282/y)
38(61/x)
10(12/x)
10(1. 45/x)
10(1. 04/x)
10{.D36/y)
10(1320/x)
10{. 468/y)
10(46. 3/x)
10(4.8/x)
10{145/x)
10(. 086/y}
10(1320/x)
10(.282/y)
10(61/x)
30{12/x)
30(1. 45/x)
30(1. 04/x)
30(.036/y)
30(1320/x)
30f. 468/y)
30(46. 3/x)
30(4.8/x)
30(145/x)
30 (.086/y)
30{1320/x)
30(.282/y)
30(61/x)
(3)
(3)
0.3(1. 04/x)
0.3(,036/y)
(3)
0.3(. 468/y)
(3)
(3)
(3)
0.3(. 086/y)
(3)
0.3(.282/y)
(3)
(3)
(3)
.86(1. 04/x)
,86(.036/y)
(3)
.86{ .468/y)
(3)
(3)
(3)
.86(. 086/y)
(3)
.86( .282/y)
(3)
(1)
(2)
(3)
X =
All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg (Ifr per million lb) of metal poured except for the Wet Sand Reclamation, Oust
Collection Scrubber, and Melting Furnace Scruhber process segments. In the case of the latter two process
segments, the annual average limitations are in units of kg/62.3 million Sm3 (ib per billion SCF) of air
scrubbed: in the case of the former process segment, the limitations are in units of kg/1000 kkg (Ib per
million lb) of sancl reclaimed.
Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
Within the range of 7.0 to 10.0 at all times.
Not regulated at RPT for this process segment.
Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific
plant.
Actual
plant.
normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific
-------
CD
-J
TABU IX-3 (Continued)
BPT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Subcategory and
P rcess
Copper
30-Day " " Daily
Max. Max»
Lead Zijic
30-Day ' " Daily 30-Day Daily
Max. Max. Max. Max.
pH
,42(12/x)
.42(1.45/x)
.42(1. 04/x)
.42(.036/y)
.42{13?n/x)
.42( .468/y)
.42(46. 3/x)
.77{12/x)
,77(1. 45/x)
.77(1. 04/x)
.77(,036/y)
-77(
.77(
-77(
1320/x)
.468/y)
46. 3/x)
4
*
*
«
*
fe
39(12/x)
39(1. 45/x)
39(1. 04/x)
39(,036/y)
'o Discharge
39(1320/x)
39(. 468/y)
39(46. 3/x)
]79{1. 45/x)
.79(1. 04/x)
,79(.036/yJ
of Pollutants
.7
-------
03
02
TABLE IX-3 (Continued)
RPT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEHATER DISCHARGES
TSS
Subcategory and
Proces_s__Segment
Ferrous
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooli ng
Slag Quench
Wet Sand
Reclamation
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Mold Cooling
30-Day
Max.
Daily
Max.
30-Day
Max.
^_Grea_se
"" Daily
Max.
15(5. 35/x)
15(5. 7/x)
15(.09/y)
15(1320/x)
15( .42/y)
15(17.7/x)
15(21 .8/x)
38(5. 35/x)
38(5. 7/x)
38(.09/y)
38(1320/x)
38 (.42/y)
38(17. 7/x)
38(21. 8/x)
10(5.35/x)
10(5.7/x)
30(5.35/x)
30(5.7/x)
_
30- Day
Max.
(3)
(3)
10(.09/y) 30(.09/y) ,3(.09/y)
No Discharge of Pollutants -•
10(1320/x) 30(1320/x) (3)
_
Daily
Max.
(3)
(3)
,86(.09/y)
(3)
10(.4Z/y)
10(17.7/x)
10(21.fl/x)
30(.42/y}
30(17.7/x)
30(21.8/x)
.3(.4Z/y)
(3)
(3)
.86(.42/y)
(3)
(3)
15(89.5/z) 38(89.5/z) 10(89.5/z) 30(89.5/z) .3{89.5/z) .86(89.5/z)
15(5.35/x)
15(1.Q4/x)
15{.243/y)
15(47.3/x)
38(5.35/x)
38(1.04/x)
38(.243/y)
38(47.3/x)
10(5.35/x)
10(1.04/x)
10(.243/y)
10(47.3/x)
30(5.35/x)
30(1.04/x)
30(.243/y)
30(47.3/x)
(3)
.3(1.04/x)
.3(.243/y)
(3)
(3)
.86(1.04/x)
.86(.243/y)
(3)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations
are in units of kg/1000 kkg fib per million Ib) of metal poured except for the Wet Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter
two process segments, the annual average limitations are in units of kg/62.3 million Sin-* (Ib per
billion SCF) of air scrubbed; in the case of the former process segment, the limitations are in units
of kg/1000 kkg (Ih per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at BPT for this process segment.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific
plant.
Y = Actual normaliled process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific
plant.
I - Actual normaliied process wastewater flow (in gallons per 1,000 pounds of sand reclaimed) for the
specific plant.
-------
TABLE IX-3 (Continued)
BPT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Suhcategory and
Process Segment
Ferrous
Casting Cleaning
Casting Ouench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reelamation
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
30-Day "Daily
Max. Max.
Lead
30-Day " " Daily
Max. Max.
Zinc
30-Day " Daily
Max. Hax.
.16(5.35/x)
.16(5.7/x)
.16{.09/y)
.16(1320/x)
.29(5.35/x) .39(5.35/x)
.29(5.7/x) .39(5.7/x)
.79(5.35/x) .56(5.35/x)
.79(5.7/x) .56(5.7/x)
.29(.09/y) .39(.09/y) .79(.09/y) .56{.09/y)
Flo Discharge of Pollutants
.29(1320/x) ,39(1320/x) .79(1320/x) ,5S(1320/x)
.16(.42/y) .29(.42/y) .39(.42/y)
.16(17.7/x) .29(17.7/x) .39(17.7/x)
.16{21.8/x) .29(21.8/x) .39(21.8/x)
.79(.42/y) .56(.42/y)
.79(17.7/x) .56(17.7/x)
.79(21.8/x) .56(21.8/x)
1,47(5.35/x) (2)
1.47(5.7/x) (2)
1.47(.09/y) (2)
1.47(1320/x) (2)
1.47(.42/y) (2)
1.47(17.7/x) (2)
1.47(21.8/x) (2)
.16(89.5/z) .29(B9.5/z) .39(89.5/z) .79(89.5/2) .56(89.5/z) 1.47(89.5/z) (2)
,42(5.35/x)
.4Z{1.04/x)
.42(.243/y)
.42(47.3/x)
.77(5.35/x) .39(5.35/x)
.77(1.04/x) .39(1.04/x)
.77(.243/y) .39(.243/y)
.77(47.3/x) .39(47,3/x)
.79(5.35/x) .43(5.35/x)
.79(1.04/x) .43(1.04/x)
.79(.243/y) ,43( .243/y)
.79(47.3/x) .43(47.3/x)
1.14(5.35/x) (2)
1.14(1.04/x) (2)
1.14(.243/y) (2)
1.14(47.3/x) (2)
(1)
(2)
(3)
X =
Y =
Z =
All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of k.g/ir>00 kkg (1b per million Ib) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scruhber process segments. In the case of the latter two
process segments, the annual average limitations are in units of kg/62.3 million Sm3 (Ib per billion
SCF) of air scrubbed; in t*ie case of the former process segment, the limitations are in units of kg/1000
kkg (Ib per nil lion Ib) of sand reclaimed.
Total Phenols - Phenols as measured by the 4-aminoarvtipyrene method (4AAP).
Within the range of 7.0 to 10.0 at all times.
Not regulated at BPT for this process segment.
Actual normalized process wastewater flow (in gallons per 1.000 pounds
of metal poured) for the specific
normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific
plant.
Actual
plant.
Actual
specific plant.
normalized process wastewater flow (in gallons per 1,000 pounds of sand reclaimed) for the
-------
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SECTION X
BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE
INTRODUCTION
As a result of the Clean Water Act of 1977, the achievement of
the best available technology economically achievable (BAT) has
become the principal means of controlling wastewater discharges
of toxic pollutants. The factors considered in assessing the BAT
include the age of equipment and facilities involved, the process
employed, process changes, nonwater quality environmental impacts
(including energy requirements), and the costs of application of
such technology. BAT effluent limitations guidelines, in general
represent the best existing economically achievable performance
of plants of various ages, sizes, processes, or other
characteristics. Emphasis is placed on technologies that further
reduce toxic pollutants discharged after the application of BPT.
Those categories whose existing performance is uniformly
inadequate may require a transfer of BAT from a different
subcategory or category. BAT may include process changes or
internal controls, even when these are not common industry
practice. BAT limitations may be based upon plant processes and
control and treatment technologies whose performance is
established by pilot studies.
TECHNICAL APPROACH TO BAT
The Agency reviewed and evaluated a wide range of technology
options to ensure that the most effective technologies were used
as the basis of BAT. To accomplish this, the Agency examined
three technology alternatives which could be applied to metal
molding and casting as BAT options and which would represent
substantial progress towards the reduction of discharges of
pollutants above and beyond the reductions achieved by BPT. The
statutory assessment of BAT considers costs, but does not require
a balancing of costs against effluent reduction benefits [see
Weyerhaeuser v. Costle, 11 ERC 2149 (D.C., Cir, 1978)]; however,
in assessing the BAT effluent limitations guidelines for the
metal molding and casting category, the Agency has carefully
considered the reasonableness of projected compliance costs,
primarily by assessing economic impacts in terms of plant
closures and job losses.
In summary, EPA considered three treatment technologies as the
basis for BAT for the metal molding and casting category. They
are:
491
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BPT: Option 2 (recycle, lime and settle) for 25 process
segments in four subcategories and complete recycle/no
discharge for the grinding scrubber process segments in the
aluminum, copper, and ferrous subcategories.
Option 3: Recycle, Lime and Settle, Filtration: This Option
adds filtration of the BPT treatment effluent for all
process segments (except grinding scrubbers) to remove
residuals of toxic heavy metals and suspended solids.
Filtration technology is considered by EPA to be among the
best available technologies (BAT) for further treatment of
lime and settle {BPT} effluents. This technology is
available and has been applied on a full-scale basis by at
least 32 plants in this industry. It is also in widespread
use in other metals categories.
Option 4: Recycle, Lime and Settle, Filtration, Activated
Carbon Adsorption: This Option adds removal of residuals of
toxic organic compounds by granular activated carbon
columns. This Option was considered for application in
further treating Option 3 effluents in the event that
treatable concentrations of organics would be present after
the application of the Option 3 model technology. This is a
technology that is commonly evaluated as a means of removing
residual organic compounds. The technology has limited
application in the metal molding and casting industry (it
has been applied at three metal molding and casting plants)
and is an available technology.
The treatment options described above are discussed in detail,
including which pollutants each controls, in Section VII. The
treatment effectiveness that can be achieved by the major
technologies, including those achievable by the BAT model
technologies also is presented in Section VII,
The Agency also considered including second stage precipitation
(sulfide or carbonate) to effect further removal of toxic metals,
BAT OPTION SELECTION
EPA has promulgated BAT mass-based effluent limitations
guidelines for all of the metal molding and casting subcategories
except the magnesium casting subcategory. For the magnesium
subcategory, EPA determined that compliance with BAT limitations
based on the control technologies considered as the basis for
final regulations in the metal molding and casting category would
not be economically achievable. The Agency's economic impact
analysis indicates that one of two direct dischargers would close
if required to install and operate the BPT model technology.
EPA has selected Option 3 (recycle, lime and settle, filtration)
as the technology basis for BAT effluent limitations guidelines
for the copper and zinc subcategories, and for the major portions
of the ferrous subcategory (all plants except those that cast
steel and small plants that cast malleable iron). As discussed
492
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previously in Section VII of this document, filtration technology
is demonstrated in the metal molding and casting industry and is
capable of effecting further removal of toxic metal pollutants
still remaining in BPT effluents, EPA has transferred treatment
effectiveness data for multimedia filtration to the metal molding
and casting category. As discussed in Section VII, EPA has data
for three of the 32 metal molding and casting plants that use
end-of-pipe filtration technology. However, none of these plants
employs all aspects of the model technologies identified by EPA
for consideration as the basis for BAT effluent limitations
guidelines. Thus, data from these three plants cannot serve as
the basis for treatment effectiveness concentrations
representative of recycle, lime and settle, plus filtration.
Achievable performance of multimedia filtration of lime and
settle effluent is discussed in detail in Section VII of this
document.
Upon completing review of treatment system performance in the
metal molding and casting industry, EPA found that those plants
that employed effective oil and grease removal technologies
effectively removed toxic organic pollutants. For this reason,
EPA rejected Option 4 as the technology basis for nationally-
applicable effluent limitations guidelines and standards.
Treatment effectiveness information for activated carbon
technology based on theoretical treatability concentrations is
presented in Section VII of this document. Some plants may elect
to use activated carbon technology.
The Agency has not adopted BAT limitations based upon residual
metals removal either by second stage sulfide precipitation or by
second stage carbonate precipitation. EPA has determined that
the concentrations of metals residuals that remain after the
application of lime and settle treatment technology are amenable
to effective removal by the application of filtration after lime
and settle. For this industry, the Agency believes that
filtration would be effective and less costly than the
application of a second metals precipitation and clarification
step.
BAT effluent limitations guidelines for the smallest plants in
the ferrous subcategory which cast primarily malleable iron and
pour less than 3,557 tons of metal per year are based on recycle,
lime and settle. The Agency's economic impact analysis
determined that the cost of complying with effluent limitations
based on filtration potentially may cause closure of one of three
malleable iron plants in this size group. Therefore, EPA
determined that the addition of filtration would not be
economically achievable for this subcategory segment.
Accordingly, the Agency is not basing BAT effluent limitations on
recycle, lime and settle, and filtration for the smallest
malleable iron plants.
The BAT effluent limitations are based on the same control and
treatment technologies {recycle, lime and settle) as BPT for all
plants in the aluminum subcategory and for those plants in the
493
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ferrous subcategory that cast primarily steel.
For the aluminum subcategory, EPA estimates that filtration would
remove an additional 0.003 kg per plant per day (0.006 Ib per
plant per day) of toxic metals. Aluminum subcategory wastewater
discharges are comprised primarily of zinc, nickel, and copper.
This contrasts with the zinc subcategory where a substantial
portion of the total toxic metals discharged is lead, which is
highly toxic, and the copper subcategory where treatable levels
of cadmium, an extremely toxic metal, remain after the
application of lime and settle treatment. The incremental costs
of the effluent reductions that filtration would achieve are
SO.31 million in investment costs and $0.26 million in total
annualized costs (1985 dollars). The Agency believes that, in
light of all these factors, filtration should not be the
technology basis for BAT effluent limitations for the aluminum
subcategory.
For the steel segment of the ferrous subcategory, .EPA estimates
that filtration would remove an additional 0.082 kg per plant per
day (0.18 Ib per plant per day) of toxic metals. These removals
would consist mainly of zinc and nickel. The incremental costs
of these incremental effluent reductions would be §0.48 million
in investment costs and $0.29 million in total annualized costs
(1985 dollars). The steel segment has not recovered from the
depressed conditions it has experienced in recent years; 1984
shipments were only about 51 percent of those in 1978, The
Agency believes that, in light of all these factors, filtration
should not be the technology basis for BAT effluent limitations
for plants in the ferrous subcategory that cast primarily steel.
REGULATED POLLUTANT PARAMETERS
As explained in Section V of this document, EPA recalculated raw
wastewater characteristics for each of the metal molding and
casting process segments in response to comments, principally
those asserting that the raw waste loads for certain segments
appeared to be in error. (Other comments noted that data were
improperly allocated to individual process segments.) In
analyzing the revised raw wastewater characteristics taking into
account raw waste variability, the Agency anticipates that
copper, lead, and zinc will be found in treatable concentrations
across all process segments. EPA has reached this conclusion, in
part, because, where copper, lead, or zinc data were unavailable
for a process segment, treatable levels of the toxic metal
pollutant were present in the discharges from all other regulated
processes employed within the subcategory for which data are
available. Therefore, the Agency is regulating copper, lead, and
zinc for all process segments. The re-evaluation of the raw
waste characteristics for the category is described in Sections V
and VI and elsewhere in the record of this rulemaking.
Additionally, after re-evaluating the raw waste load data/ the
Agency found total phenols (4AAP) above treatable concentrations
in raw wastewaters for ten process segments and toxic organic
494
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pollutants in treatable concentrations in raw wastewaters for 22
process segments. Because EPA has not identified any
technologies that will result in significant incremental
reductions in total phenols, total phenols have been regulated at
the BPT level in the following 10 process segments:
Aluminum Subcategory:
Copper Subcategory:
Ferrous Subcategory:
Zinc Subcategory:
die casting
dust collection scrubber
melting furnace scrubber
dust collection scrubber
melting furnace scrubber
dust collection scrubber
melting furnace scrubber
wet sand reclamation
die casting
melting furnace scrubber
EPA is not establishing BAT effluent limitations guidelines for
toxic organic compounds because the Agency determined that
compliance with the BPT effluent limitations for oil and grease
provides effective removal of toxic organic compounds.
Filtration is not expected to achieve appreciable incremental
removals of toxic organics from metal molding and casting
wastewaters over those achieved by oil removal technologies.
EPA also considered establishing BAT effluent limitations
guidelines for the following toxic metals in the following
subcategories:
Copper Subcategory:
Ferrous Subcategory:
cadmium, chromium, nickel
antimony, cadmium, chromium? nickel,
selenium
These pollutants were found at treatable levels in those
subcategories. EPA has decided not to establish specific
limitations for these metals because they will be effectively
controlled when the regulated pollutants are controlled to the
specified BAT levels. This approach is technically justified
since the treatable concentrations used for lime precipitation
and sedimentation technology are based on optimized treatment for
concomitant multiple metals removal. Thus, even though metals
have somewhat different theoretical solubilities, they will be
removed at very nearly the same rate in lime precipitation and
sedimentation treatment system operated for multiple metals
removal. Similarly, filtration removes precipitated metals
nonpreferentially.
BAT FLOW
EPA established the flow bases of BPT on the lowest flow rates
that the Agency believed were generally achievable for each
495
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subcategory segment (see Section IX). Thus, the flow bases of
BPT also represent the best available flow rates for this point
source category. BAT normalized flows may be found in Table X-l.
BAT EFFLUENT LIMITATIONS
The BAT mass limitations {mass of pollutant allowed to be
discharged per mass of metal poured, mass of sand reclaimed, or
volume of wet scrubber air flow) are presented in Table X-2,
These limitations were calculated for each regulated pollutant in
each process segment as follows: the BAT normalized flow for each
discharge segment (see Table X-l) was multiplied by the one-day
maximum and by the maximum monthly average treatment
effectiveness concentrations (see Tables VII-12 and VII-14)
corresponding to the the BAT technology option selected for each
subcategory. As explained in Section VII, the maximum monthly
average treatment effectiveness concentration is based on the
average of 10 samples over the period of a month.
The BAT limitations presented at proposal assumed that discharges
from metal molding and casting plants would always be on a
continuous basis. Information submitted in comments and
confirmed by EPA indicate that treatment may be done on a batch
basis with discharge on an intermittent basis.
To allow this practice to continue where plants find batch
treatment to be an effective control technique, the final
regulations contain provisions that would allow metal molding and
casting plants to discharge on an intermittent basis provided
that they comply with annual average BAT limitations that are
equivalent to the BAT effluent limitations applicable to
continuous discharging plants. Plants are eligible for the
annual average limitations and standards where wastewaters are
stored for periods in excess of 24 hours to be treated on a batch
basis. NPDES permits established for these "noncontinuous"
discharging plants must contain concentration-based maximum day
and maximum for monthly average limitations established for
continuous discharging plants. BAT effluent limitations
applicable to intermittent discharging plants are shown in Table
X-3.
COST OF APPLICATION AND EFFLUENT REDUCTIONS BENEFITS
Implementation of the BAT effluent limitations will remove an
additional 3,100 kg/yr {6/800 Ib/yr) of toxic metals beyond BPT,
at a total incremental investment cost {beyond equipment in-
place) of $3.9 million and an incremental total annual cost of
$2.3 million {1985 dollars). EPA has found this to be reasonable
further progress in reducing the discharge of pollutants from
those levels discharged after application of BPT technology.
NON-WATER QUALITY ASPECTS OF BAT
The following are the non-water quality environmental impacts
{including energy requirements) associated with the BAT effluent
496
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limitations guidelines.
Air Pollution
Application of the BAT will not create any incremental air
pollution problems beyond those that would occur through the
application of the best practicable control technology currently
available. Filtration does not emit pollutants to the air.
Solid Waste
EPA estimates that application of the best available technology
economically achievable will increase the quantity of sludges
that must be landfilled by plants in the metal molding and
casting category by about 240 kkg (265 tons) per year beyond BPT
levels. The increase in the quantity of oily wastes generated
will be negligible. As discussed in Section VIII of this
document, the Agency examined the solid wastes that would be
generated by metal molding and casting processes using the model
treatment technologies and has concluded that they are not likely
to be hazardous under Section 3001 of the Resource Conservation
and Recovery Act (RCRA). Even though metal molding and casting
wastes are not identified as hazardous, they still must be
disposed of in a manner that will not violate the open dumping
prohibition of section 4005 of RCRA.
Consumptive Water Loss
The application of filtration technology will not result in any
significant evaporation of wastewater. Therefore, compliance
with the BAT effluent limitations guidelines is not expected to
result in any incremental consumptive water loss compared to that
which would occur as a result of compliance with the BPT effluent
limitations guidelines.
Energy Requirements
EPA estimates that compliance with the BAT effluent limitation
guidelines will result in a total electrical energy consumption
of 4.2 x 10" kilowatt-hours per year in addition to the
energy usage to comply with BPT. This is equivalent to an
increase of about 0.013 percent over the 31.3 x Id9 kilowatt-
hours used in 1978 for production purposes.
497
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Table X-l
APPLIED FLOW RATES, RECYCLE RATES, AND DISCHARGE RATES THAT FORM THE BASIS OF BAT
Casting Cleaning
Casting Quench
Die Casting
Dual Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace Scrubber
Hold Cooling
Copper
Casting Quench
Direct Chill Casting
Duat Collection Scrubber
Grinding Scrubber
Investment Casting
Kelt Ing Furnace Sorubber
Hold Cooling
Ferrous
Casting Cleaning
Casting Quench
Dust Collection Scrubber
Grinding Scrubber
Inwe^tnent Casting
Melting Furnace Scrubber
Production
Normalized
Applied Flo« Bate
180 gal/ton
115 gal/ton
4).4 gal/ton
1.78 gal/1,000 SCF
0.063 gal/1,000 SCF
17,600 gal/ton
11.7 gal/1,000 SCF
1,850 f-~ 'ton
478 gal/ton
5,780 gal/ton
4.29 gal/1,000 SCF
0.111 gal/1,000 SCF
17,600 gal/ton
7.01 gal/t,000 SCF
2,150 gal/ton
213 gal/ton
57) gal/ton
3.0 gal/1,000 SCF
3.17 gal/J,000 SCF
17,600 gal/ton
10.5 gal/1,000 SCF
Production
Normalizing Recycle
Parameter Bate
ton of oietel poured 951
ton or metal poured 981
ton oT netal poured 951
1,000 SCF of air 98J
floy through the
scrubber
1,000 SCF of air 100J
flow through the
scrubber
ton of netal poured 85!
1,000 SCF of air 961
flow through the
scrubber
ton oT metal poured 95S
ton or raetal poured 981
ton oT neta! poured 951
1,000 SCF of air 9B»
flow through the
scrubber
1,000 SCF of air 1001
flow through the
scrubber
ton of netal poured fl^l
1,000 SCF of air 96J
flow through the
scrubber
ton of metal poured 951
ton of metal poured 951
ton of metal poured 981
1,000 SCF of air 97*
flow through the
scrubber
1,000 SCF of air 100J
flow through the
scrubber
ton of netal poured 851
1,000 SCF of air 9&J
flow through the
scrubber
Production
Normal lied
Dlacfaarge
2M.O gal/ton
2.90 gal/ton
2.07 gal/ton
0.036 gal/1,000
SCF
0
2,640 gal/ton
O.H68 gal/!,000
SCF
92,5 gal/ton
9.56 gal/ton
289 gal/ton
0,086 gal/1,000
SCF
0
2.6HO gal/ton
0.2fl2 gal/1,000
SCF
122 gal/ton
10.7 gal/ton
II.4 gal/ton
0,090 gal/1,000
SCF
0
2,610 gal/ton
0.1(20 gal/1,000
SCF
-------
Table X-l (Continued)
APPLIED FLOW RATES, RECYCLE RATES, AND DISCHARGE RATES THAT FORM THE BASIS OF BAT
ess Segment
VD
Ferrous (Cont. )
Hold Coaling
SlBfl Quench
Vet Sand R«ola»ation
Zinc
Casting Qyanch
Dl« Casting
Halting Furnace Scrubber
Hold Cooling
Product Ion
Norualiitd
incited Flou
707 gal/ton
727 g«l/ton
fl95 gal/ton
5i3 gal/ton
41.4 gal/ton
6.07 i»l/1,000 SCF
1,890 gal/ton
Production
MorMlittng
Paraaeter
fieoyole
Jata
Production
Homallied
flam*
ton of *elBl poured 951
ton of Metal poured 9^1
ton of sand reellined 80S
ton of petul poured 981
ton of *etal poured 951
1,000 scr or *ir 961
flow through the
scrubber
ton of metal poured 951
3!>.4 gal/ton
43.6 gal/ton
179 gal/ton
10.7 gal/ton
2.0? gal/ton
0.2*3 |«J/t,000
SCF
1.b gal/ton
•Flou baala Tor HBSS limitations.
-------
TABLE X-2
BAT LIMITATIONS* COVERING CONTINUOUS DIRECT OISCHARGES
Subcategory and
Aluminum
('.loaning
Casting Quench
Pie Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
PhenoUJlJ
30-Pay" Da fly
Max. Max.
'3)
(3)
.0026
.09
(3)
1.17
(3)
(3)
(3)
.0074
.258
(3)
3.36
(3)
.0421
.0051
.ofi36
.126
--Nn
4.63
1.64
.16?
Copper
30-Day " D'aily
Max. Max.
.0771
.0093
.0066
L_e_ajJ
30-Day ^Daily
Max. Max.
.039
.0047
.0034
.231 .117 .2
No Discharge of Pollutants
8.48 4.3 8.7
{3}
(3)
.215
(3)
.706
(3}
(3)
(3)
.617
(3)
2.02
(3)
.0
.5
.3
4.6
.9
.2
3.01
.297
.0307
.928
1.R2
.151
.0104
.314
3.09
01 .553 .187 .3
No Discharge of Pollutants
3 8.48 2.86 5.84
1.81
.392
,612
.132
1.25
Zin_c
30-Day* Daily
Max. Max.
pH
791 .0431
096 .0052
068 .0037
37 .129
4.74
3 1.68
05 .166
.114
.0138
.0098
.343
12.6
4.45
.44
(2}
(2)
(2)
(2)
{2}
(2)
(2)
211 .0115
3g .35
8 .208
4 3.19
5 .673
7 .148
.0303
.916
.545
8.37
1,79
,387
(2)
(2)
(2)
(2)
(2)
(2)
* All limitations are in units of kg/1000 kkg (lb per million lb) of metal poured except
for the Wet Sand Reclamation, Dust Collection Scrubber, and Helting Furnace Scrubber
process segments. In the case of the latter two process segments, the limitations are in
units of kg/62.3 million Sm3 (lb per billion SCF) of air scrubbed; in the case of the
former process segment, the limitations are in units of kg/1000 kkg (lb per million 1b)
of sand reclaimed.
fl) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(?.} Within the range of 7,0 to 10.0 at all times.
(3) Not regulated at BAT for this process segment.
500
-------
TABLE X-2 (Continued;
Suocategory and
£r ojce ss_ JS e gment
Ferrous(4)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
Slag Quench
Wet Sand
Reclamation
Ferrous{5)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reelamation
Pheno'
30- Day
Hax.
ls(l)
Daily
Hax,
.Q°PJ
30-Day
Max.
ser
Daily
Hax.
Le<
30-Day
Hax.
id
Daily
Max.
Zii
30-Day
Hax.
1C
Daily
Hax.
(3)
(3)
.225
(3)
1.05
(3)
(3)
(3)
(3)
.646
(3)
3.D1
(3)
(3)
.0
.c
.1
1.7
.5
.C
.0
.0129 .0116 .0237 .0165 .0437 (2)
.0138 .0124 .0252 .0176 .0466 (2)
.278
.736 (2)
2 .218 .195 .398
No Discharge of Pollutants— -
6 3.19 2.86 5.84 4.07 10.8 {2}
1.02 ,911 1.86 1.3 3.44 (2)
.0428 .0384 .0783 .0546 .145 (2)
.0527 .0473 .0964 .0673 .178 (2)
,224
(3)
(3)
.225
"(3)"
1,05
(3}
(3)
.224
.642
(3)
(3)
.656
.12
.217
.194
.396
.276
.732 (2)
.0071 .0129 .0174 .0353 .025 .0656 {2}
.0076 .0138 .0185 .0376 .0266 .0699 (2)
.421
.12 .218 .293 .593
No Discharge of Pollutants
1.76 3.19 4.3 8.7 6.17
1.1
16.2
3.01
(3)
(3)
.642
,561 1.02 1,37 2.77
.0236 .0428 .0576 .117
.0291 .0527 .0709 .144
.12
.217
.291
.59
1.96
.0827
.102
.418
1.1
{2}
(2)
5.15 (2)
.217 {2}
.267 (2)
(2)
* All limitations are in units of kg/1000 kkg (Ib per million Ib) of metal poured except
for the Wet Sand Reclamation, Dust Collection Scrubber, and Melting Furnace Scrubber
process segments. In the case of the latter two process segments, the limitations are
in units of kg/62.3 million Sm^ (lb per billion SCF) of air scrubbed: in the case of the
former process segment, the limitations are in units of kg/1000 kkg (lb per million Ib)
of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7,0 to 10.0 at all times.
(3) Not regulated at BAT for this process segment.
{4} Applicable to plants that cast primarily malleable iron where greater than 3,557 tons of
metal are poured per year and to plants that cast primarily ductile or gray iron.
(5) Applicable to plants that cast primarily malleable iron where equal to or less than
3,557 tons of metal are po'ured per year and to plants that cast primarily steel.
501
-------
TABLE X-2 (Continued)
____ ...
Subcategory and 30-Day" Daily 30- Day Daily 30- Day Daily 30-Day Dally
Process Segment _Ji^.x_*_ Ma_x_. 1^x_*_ 1*** _^
-------
TABLE X-3
BAT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Subcategory and
Process Segment
Aluminum
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
Phenol s_U)_
30-DayDaily
Max. Max.
Cqjjper
30-Day" " "Daily
Max. Max.
Lead
30-Day " ~ Daily
Max. Max,
Zinc
30-Day' * " Daily
Max. Max.
Ul
o
(3) (3) .42(12/x) .77{12/x) .39{12/x) ,79{l?/x) .43(12/x) 1.14(12/x) (2)
(3) (3) ,42{1.45/x) .77{1.45/x) .39(1.45/x) .79(1.45/x) .43(1.45/x} 1.14(1.45/x) {2}
.3(1.04/x) .86(1.04/x).42(1.04/x) .77(1.04/x) .39(1.04/x) .79(1.04/x) .43(1.04/x) 1.14(1.04/x) (2)
.3(.036/y) ,86(.Q36/y).42f.Q36/y) .77(.036/y) .39{.n36/y) ,79{.036/y) ,43(,036/y) 1.14(.Q36/y) (2)
, _—_.,, __NO Discharge of Pollutants
(3) (3) .42(1320/x) .77(1320/x) ,39(132Q/x) .79{1320/x) .43{1320/x) 1.14(1320/x) (2)
,3(.468/y) .86{,4fi8/y).42(.468/y) .77(.468/y) .39{.468/y) ,?9{.468/y) ,43{.468/y) 1.14(.468/y) (2)
(3) (3) .42(46.3/x) .77(46.3/x) .39{4i»3/x) .79(46.3/x) ,43{46.3/x) 1.14(46.3/x) (2)
Copper
Casti ng Quench
Direct Chil 1 Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
(3)
(3)
,3(.086/y)
(3)
.3(. 282/y)
(3)
(3)
(3)
,86(
(3)
.86(
(3)
.42(4.8/x)
.42(145/x)
.086/y}.42(.086/y)
.42{U20/x)
. 282/y). 42(. 282/y)
.42(61/x)
,77(4.8/x) ,26(4, 8/x)
.77(145/x) ,26(145/x)
.77(.086/y) .26( ,086/y)
-No Discharge of Pollutar
.77(1320/x) .26(1320/x)
.77(.282/y) .26( .282/y)
.77(61/x) .26(61/x)
.53(4. 8/x)
.53(145/x)
.53(.086/y)
1^5--— -------
.53(13PO/x)
.53(. 282/y)
.53(61/x)
,29(4.8/x)
.29{145/x)
.29(.n86/y)
.29(1320/x)
.29(. 282/y)
.29(61/x)
.76(4.8/x)
.76(I45/x)
.76(.086/y)
.76(1320/x)
.76(. 282/y)
.76(61/x)
w
w
(2)
(2)
(2}
(2)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are in units
of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Oust Collection Scrubber,
and Melting Furnace Scrubber process segments. In the case of the latter two process segments, the annual average
limitations are in units of kg/62,3 million Sm^ fib per billion SCF) of air scrubbed; in the case of the former
process segment, the5 limitations are in units of kg/1000 kkg {Ib per million Ih) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP)
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at BAT for this process segment.
X = Actual normalized process wiitewater How (in gallons per 1,000 pounds of metal poured) for the specific plant,
Y = Actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific plant.
-------
UI
o
Subcategory and
Prpces_s_ Segment
Ferrous(4)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
Slag Quench
Wet Sand
Reclamation
TABLE X-3 (Continued)
BAT LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Phenol_sj 1)
30-Day ~" Da fly
Max. Max.
30-Day
Max,
Cp_£p_e_r
Lead
Zinc
Daily
Max.
3n-Day
Max.
Dally
Max.
30-Day"
Max.
Daily
Max.
(3)
(3)
(3)
(3)
.16{5.35/x) ,29(5.35/x).26(5.35/x).53(5.35/x).37(5.35/x).98(5,35/x) (2)
.16(5.7/x) .29(5.7/x) .26(5.7/x) .53(5.7/x) .37(5.7/x) .98(5.7/x) (2)
(2)
.3(.09/y) .86{,09/y) .16(,09/y) ,29(.09/y) .26(.09/y) .53(.09/y) .37(.09/y) .98(-09/y)
. No Discharge of Pollutants
(3) {3} .16(1320/x) .29(1320/x).26(1320/x).53{1320/x).37(1320/x).98(1320/x) (2)
.3(.42/y) »86{.42/y) .16(.42/y) .?9(.42/y) .26(.42/y) .53{.42/y) .37{.42/y) .98(.42/y) {2}
(3) (3) .16(17.7/x} .29(17.7/x).26(17.7/x).53(17.7/x).37{17.7/x).98{17.7/x) {2)
(3) (3) .16(21.8/x) .29(21.8/x).26(21.8/x).53(21.8/x).37(21.8/x).98(21.8/x) (2)
.3(89.5/2) .86(89,5/2} .16(89.5/2} .29(89.5/z).29(89,5/z).53(89.5/z).37(89.5/z}.98(89.5/z) (2)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are in units
of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust Collection Scrubber,
and Melting Furnace Scrubber process segments. In the case of the latter two process segments, the annual average
limitations are in units of kg/62/3 million Sm^ (Ib per billion SCF) of air scrubbed; in the case of the former
process segment, the limitations are in units of kg/1000 kkg (Ib per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at BAT for this process segment.
(4) Applicable to plants that cast primarily malleable iron where greater than 3,557 tons of metal are poured per
year and to plants that cast primarily ductile or gray iron.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific plant.
Y = Actual normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific plant.
Z = Actual normalized process wastewater flow (in gallons per 1,000 of sand reclaimed) for the specific plant.
-------
Subcategory and
Pro_ce_s_s_ Segment
Ferrous{5)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grindi ng Scrubber
Investment Casti ng
Melting Furnace
Scrubber
Hold Cooling
Slag Quench
Wet Sand
Reclamation
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Hold Cooling
TABLF X-3 (Continued)
RAT LIMITATIONS* COVERING NON-CONTINUOUS 01RECT WASTEWATER DISCHARGES
P_heno_\s_U_)
3D-Day~" Dafly
Max. Max.
30-Day
Max.
Cop_p_e_r
Lead
Zinc
Max.
30-Day"
Max.
Daily
Max.
30-Day'
Max.
Daily
Max.
(3)
(3)
>3{.09/y)
(3)
(3)
(3)
.86(.Q9/y)
"(3)
.16(5.35/x) .29(5.35/x).39(5.35/x).79(5.35/x).56(5.35/x)1.47(5.35/x) (2}
.16(5.7/x) .29(5.7/x) .39(5.7/x) .79(5.7/x) .56(5.7/x) 1.47(5.7/x) {2}
(2)
.16{.09/y) .29{.09/y) .39(.D9/y) .79(.09/y) .56(.09/y) 1.47(.09/y)
No Discharge of Pollutants
,16(1320/x) .29(1320/x).39(1320/x).79(1320/x).56(1320/x)1.47(1320/x) {2}
.16(.42/y) ,29(.42/y) .39{.42/y) .79(.42/y) .56( .42/y) 1.47(.42/y) (2)
.16(17.7/x) .29(17.7/x).39(17.7/x).79(17.7/x).56(17.7/x)1.47(17.7/x) (2)
.29(21.8/x).39(21.8/x).79(21.8/x).56(21.8/x)1.47(21.8/x) {2}
,3(.42/y) .86(.42/y)
(3) (3)
(3) (3)
.3(89.5/z) .86(89.5/z) .16(89.5/z) .29(89.5/z).39(89.5/z).79(89.5/z).56(89.5/z)1.47(89.5/z) (2)
(3) (3) .42(5.35/x) .77(5.35/x).26(5.35/x).53(5.35/x).29(5.35/x).76(5.35/x) (2)
.3(1.04/x) .86(1.04/x) .42(1.04/x) .77(1.04/x).26(1.04/x).53(1.04/x).29(1.04/x).76(1.04/x) (2)
.3(.243/y) .86{.?43/y) .42(.243/y) .77{,243/y).26{,243/y).53(,243/y),29(.243/y).76(.243/y) (2}
(3) (3) .42(47.3/x) .77(47.3/x).26(47.3/x).53(47.3/x).29(47.3/x).76{47.3/x) (2)
* A11 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are in units
of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust Collection Scrubber,
and Melting Furnace Scrubber process segments. In the case of the latter two process segments, the annual average
limitations are in units of kg/62.3 million Sm^ (lh per billion SCF) of air scrubbed; in the case of the former
process segment, the limitations are in units of kg/1000 kkg (1b per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all tines.
(3) Not regulated at BAT for this process segment.
(5) Applicable to plants that cast primarily malleable iron where equal to or less than 3,557 tons of metal are
poured per year and to plants that cast primarily steel.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific plant.
Y = Actual normalized process wastewater flow (in gallons per 1.000 SCF of air scrubbed) for the specific plant.
Z = Actual normalized process wastewater flow (in gallons per 1,000 of sand reclaimed} for the specific plant.
-------
-------
SECTION XI
BEST CONVENTIONAL POLLUTANT CONTROL TECHNOLOGY
The 1977 Amendments added Section 301(b)(2)(E) to the Act
establishing the "best conventional pollutant control technology"
{BCT) for discharges of conventional pollutants from existing
industrial point sources. Conventional pollutants are those
defined in Section 304{a)(4) [biological oxygen demanding
pollutants {e.g., BOD5_), total suspended solids (TSS), fecal
coliform, and pH], and any additional pollutants defined by the
Administrator as "conventional" (oil and grease, 44 FR 44501,
July 30, 1979).
BCT is not an additional limitation but replaces BAT for the
control of conventional pollutants. In addition to other factors
specified in Section 304{b)(4)(B), the Act requires that BCT
limitations be assessed in light of a two part "cost-
reasonableness" test. American Paper Ijistitute v. EPA, 660 F,2d
954 (4th Cir. 1981). The first test compares the cost for
private industry to reduce its conventional pollutants with the
costs to publicly owned treatment works for similar levels of
reduction in their discharge of these pollutants. The second
test examines the cost-effectiveness of additional industrial
treatment beyond BPT. EPA must find that limitations are
"reasonable" under both tests before establishing them as BCT.
In no case may BCT be less stringent than BPT.
EPA has determined that the treatment alternatives considered in
this rulemaking that are more stringent than the best practicable
control technology currently available are capable of removing
significant amounts of conventional pollutants. Therefore, EPA
is deferring establishing BCT limitations for this category until
a BCT methodology has been promulgated.
507
-------
-------
SECTION XII
NEW
INTRODUCTION
The basis for new source performance standards (NSPS) under
Section 306 of the Clean Water Act is the best available
demonstrated technology (BDT). New plants have the opportunity
to design the best and most efficient production processes and
wastewater treatment technologies. Therefore, NSPS includes
process changes, in-plant controls (including elimination of
wastewater streams), operating procedure changes, and end-of-pipe
treatment technologies to reduce pollution to the maximum extent
possible.
This section describes the control technology for treatment of
wastewater from new sources and discusses mass discharge
standards for regulated pollutants, based on the described
control technologies,
TECHNICAL APPROACH TO ESTABLISHING
The Agency considered four technology options which might be
applied as the best available demonstrated technology. These
options are identical to those considered for BAT and are
described in detail in Section VII, The options are summarized
below:
Option 2: Recycle, lime and settle.
Option 3: Recycle, lime and settle, filtration.
Option 4: Recycle, lime and settle, filtration, activated
carbon adsorption.
Option 5: Complete recycle, no discharge (grinding scrubber
process segments only).
The data relied upon for selection of NSPS were the data
developed for the evaluation of treatment Options 2 through 5 for
existing sources. It is likely that compliance costs would be
lower for new sources than for equivalent existing sources.
Production processes can be designed at new sources on the basis
of lower flows and there will be no costs associated with
retrofitting the in-process controls. Therefore, new sources,
regardless of whether they are existing plants with major
modifications or greenfield sites, will have costs that are not
greater than the costs that existing sources would incur in
achieving equivalent pollutant discharge reductions. On this
basis, the Agency believes that the final NSPS are appropriate
for both greenfield sites and existing sites undergoing major
modifications.
509
-------
NSPS TECHNOLOGY OPTION SELECTION
For the reasons explained In Section X, EPA has promulgated NSPS
for all regulated subcategories on the basis of the same
technologies as for BAT. New sources in the magnesium
subcategory are not regulated by NSPS because the costs of
compliance with standards based on the treatment technologies
identified in this rulemaking, which would have resulted in
closure for one of two existing sources, are likely to serve as
barriers to entry into magnesium casting.
NSPS are based on Option 5 {complete recycle with no discharge)
for the grinding scrubber process segments of the aluminum,
copper, and ferrous casting subcategories. For the remaining
process segments: (a) NSPS are based on Option 3 (recycle, lime
and settle, filtration) for the copper and zinc subcategories and
for the major portions of the ferrous subcategory (all plants
except those that cast primarily steel or that pour less than
3,557 tons of metal per year and cast primarily malleable iron);
(to) NSPS are based on Option 2 (recycle,, lime and settle) for
the aluminum subcategory as well as for plants in the ferrous
subcategory that cast primarily steel or that cast primarily
malleable iron and pour less than 3,557 tons of metal per year.
Regulations based on the selected technology options will not
preclude the entry of new plants into the industry,
REGULATED POLLUTANT PARAMETERS
EPA has established NSPS controlling all toxic, nonconventional,
and conventional pollutants regulated at BPT and BAT. These are:
copper, lead, zinc, total phenols, oil and grease, suspended
solids (TSS), and pH. For the reasons explained in Section X,
EPA is not establishing NSPS controlling toxic organic compounds.
EPA has determined that compliance with the oil and grease
standards will ensure effective control of toxic organic
compounds discharged from plants in the metal molding and casting
industry.
NSPS FLOW
EPA established the flow bases of BPT/BAT at the lowest flow
rates that the Agency believed were generally achievable for each
subcategory segment (see Sections IX and X). Thus, the flow
bases of BPT/BAT also represent the best available demonstrated
flow rates for the metal molding and casting point source
category. Table XII-1 presents the NSPS normalized flow for each
process segment,
NSPS EFFLUENT STANDARDS
The NSPS mass effluent standards (mass of pollutant allowed to be
discharged per mass of metal poured, mass of sand reclaimed, or
volume of wet scrubber air flow) are presented in Table XII-2.
These li<^ Cations were calculated for each regulated pollutant in
510
-------
each process segment as follows: the NSPS normalized flow for
each discharge segment (see Table XII-1) was multiplied by the
one-day maximum and by the maximum monthly average treatment
effectiveness concentrations (see Tables VII-12 and VII-14)
corresponding to the NSPS technology option selected for each
subcategory. As explained in Section VII, the maximum monthly
average treatment effectiveness concentration is based on the
average of 10 samples over the period of a month.
The NSPS effluent standards presented at proposal assumed that
discharges from metal molding and casting plants would always be
on a continuous basis. Information submitted in comments and
confirmed by EPA indicate that treatment may be done on a batch
basis with discharge on an intermittent basis.
To allow this practice to continue where plants find batch
treatment to be an effective control technique, the final
regulations contain provisions that would allow metal molding and
casting plants to discharge on an intermittent basis provided
that they comply with annual average NSPS effluent standards that
are equivalent to the NSPS effluent standards applicable to
continuous discharging plants. Plants are eligible for the
annual average limitations and standards where wastewaters are
stored for periods in excess of 24 hours to be treated on a batch
basis. NPDES permits established for these "noncontinuous"
discharging plants must also contain concentration-based maximum
day and maximum for monthly average standards as shown in Table
XII-3.
COST OF APPLICATION AND EFFLQENT REDCJCTIONS BENEFITS
EPA anticipates that new metal molding and casting plants subject
to NSPS that use wet scrubbing devices will remove toxic metal,
toxic organic, and nonconventional pollutants at approximately
the same rates as will be removed by existing sources subject to
the BAT effluent limitations guidelines. On a per-plant basis,
conventional pollutant removals at new sources are expected to be
comparable to conventional pollutant removals at existing sources
complying with the BPT effluent limitations guidelines, except
that, where NSPS are based on Option 3, suspended solids removals
will be somewhat greater than at BPT. Costs for new sources
employing wet scrubbers are also expected to be comparable to
those incurred by existing sources, although some piping and
retrofit costs (e.g., stream segregation) will not be incurred by
new source direct discharging plants. I£ dry scrubbers are used,
both costs and pollutant removals will be reduced considerably.
NON-WATER QUALITY ASPECTS OF NSPS
Because NSPS have been established on the basis of the same
control and treatment technologies as BPT and BAT, compliance
with NSPS will not cause any incremental air pollution or solid
waste generation, water consumption, or energy usage compared to
compliance with the BPT and BAT effluent limitations guidelines.
511
-------
Table XII-1
APPLIED FLOW RATES, RECYCLE RATES, AND DISCHARGE RATES THAT FORM THE BASIS OF NSPS
aa Segment
Aluminum
Casting Cleaning
Casting Quench
Die Casting
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Helting Furnace Scrubber
Hold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace Scrubber
Hold Cooling
Ferrous
Casting Cleaning
Casting Quench
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
Helting Furnace Scrubber
Production
Normalized
Applied FlQH Rate
480 gal/ton
115 gal/ton
H1.1 gal/ton
1.78 gal/1,000 SCF
0.063 gal/1,000 SCF
17,600 gal/ton
It.7 gal/I,000 SCF
t,850 gal/ton
gal/ton
5,780 gal/ton
H.29 gal/1,000 SCF
O.H1 gal/1,000 SCF
17,600 gal/ton
7.0*1 gal/1,000 SCF
2,150 gal/ton
213 gal/ton
571 gal/ton
3.0 gal/1,000 SCF
3.17 gal/1,000 SCF
17,600 gal/ton
10.5 gal/1,000 SCF
Production
Normalising Recycle
Parameter Bate
ton of metal poured ' 951
ton oT metal poured 981
ton of neta! poured 951
1,000 SCF of air 98J
flow through the
scrubber
1,000 SCF of air 100$
flow through the
scrubber
ton oT metal poured 85$
1,000 SCF of air 96»
flow through the
scrubber
ton of metal poured 95J
ton of metal poured 981
ton of aetal poured 951
1,000 SCF of air 98!
flow through the
scrubber
1,000 SCF of air 1001
flow through the
scrubber
ton of metal poured 851
1,000 SCF of air 96J
flow through the
scrubber
ton of metal poured 95$
ton of metal poured 95%
ton of metal poured 981
1,000 SCF of air 97J
flow through the
scrubber
1,000 SCF of air 10QJ
flow through the
scrubber
ton of metal poured 851
1,000 SCF of air 96J
flow through the
scrubber
Production
Normalized
Discharge Flow*
21.0 gal/ton
2.90 gal/ton
2.07 gal/ton
0.036 gal/1,000
SCF
0
2.6HO gal/ton
O.H68 gal/1,000
SCF
92.5 gal/ton
9.56 gal/ton
289 gal/ton
0.086 gal/1,000
SCF
2.6MO gal/ton
0.282 gal/1,000
SCF
122 gal/ton
10.7 gal/ton
11.1 gal/ton
0.090 gal/1,000
SCF
0
2.6MO gal/ton
OJI20 gal/1,000
SCF
-------
Table XII-1 (Continued)
APPLIED FLOW EATES, RECYCLE , AMD DISCHARGE THAT THE OF
Ferrous CCont. )
Hold Cooling
Slag Quench
Wet Sand Reclamation
Zinc
Casting Quench
Die Casting
Melting Furnace Scrubber
Hold Cooling
Production
Normaltzed
ed Flow Rate
Production
Normalizing
Parameter
Recycle
Bate
Production
Noraalized
Flou*
707 gal/ton
727 gal/ton
895 gal/tan
533 gal/ton
ill.il gel/ton
6.07 gal/t,000 SCF
1,890 gal/ton
ton of Metal poured 951
ton of natal poured 94S
ton of sand reclaimed BOf
ton of metal poured 961
ton of neta! poured 954
1,000 SCF of air 96*
flow through th«
scrubber
ton of metal poured 95%
35.1 gal/ton
43.6 gal/ton
179 gal/ton
10.7 gal/ton
2.07 gal/ton
0.213 gal/1,000
SCF
i«,5 gal/ton
•Flou basis for mass 1 Imitations.
-------
TABLE XII-2
NSPS LI HI TATIDNS* COVERING CONTINUOUS DIRECT DISCHARGES
TSS Oil & Grease Phenols{l)
Lead
Zinc
Subcategory and
Process Segment
Al umi num
Casting Cleaning
Casting Quench
Die Casting
Dust Col lection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
u, Copper
£ Casting Quench
Direct Chill
Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
30-Day
Max.
1.50
.182
.13
4.51
165
58.6
5.79
.479
14.5
8.61
132
28.2
6.11
Daily
Max.
3.80
.46
.33
11.4
419
148
14.7
.598
18.1
10.8
165
35.3
7.63
30-Day
Max.
1.0
.1?!
.0864
3.0
110
39.1
3.86
.399
12.1
7.18
110
23.5
5.09
Daily
Hax.
3.0
.363
.259
9.01
330
117
11.6
1.2
36.2
21.5
330
70.6
15.3
30-Oay
Max.
(3)
{3}
.0026
.09
Nn
(3)
1.17
(3)
(3)
(3)
.215
Nn
(3)
.706
(3)
Daily
Max.
(3}
(3)
.0074
.258
Discharge
(3)
3.36
(3)
(3)
(3)
.617
Discharge
(3)
2.02
(3}
30-Oay
Hax.
.0421
.0051
.0036
.126
of Pol
4.63
1.64
.162
.0168
.506
.301
of Pol
4.63
.988
.214
Daily
Hax.
.0771
.0093
.0066
.231
8.48
3.01
,297
.0307
.928
.553
8.48
1.81
.392
30-Day
Hax,
.039
.0047
.0034
.117
4.3
1.52
,151
.0104
.314
.187
2.86
.612
,132
Daily
Hax.
.0791
.0096
.0068
.237
8.7
3,09
.305
.0211
.639
.38
5.84
1.25
.27
3D-Oay
Max.
.0431
.0052
.0037
.129
4.74
1,68
.166
.0116
.35
.208
3.19
.673
.148
Daily
Max. pH
.114 (2)
.0138 (2)
,0098 (2)
.343 (2)
12.6 (2)
4.45 (2)
.44 (2)
.0303(2}
.916 (2)
,545 (2)
8.37 (2)
1.79 (2)
.387(2}
(1)
(2)
All limitations are in units of kg/1000 kkg {lb per million 1b) of metal poured except for the Met Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 million Sm^ (lb per billion SCF) of air scrubbed; in the case of
the fonmer process segment, the limitations are in units of kg/1000 kkg (Ib per million 1b) of sand reclaimed.
Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP)
Within the range of 7.0 to 10,0 at all times.
(3) Not regulated at NSPS for this process segment.
-------
Subcategory and
Process Segment
Ferrous(4)
Casting Cleaning
Casting Quench
Oust Col lection
Scruhber
Grinding Scruhber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
SIag Quench
Wet Sand
Reelamation
TABLE XII-2 (Continued)
NSPS LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
TSS
Phe_np_\s[lJ
JL°-PJleJL
Lead
Zinc
30-Day
Max.
.536
.571
9.01
132
42.1
1.77
2.18
Daily
Max,
.67
.713
11.3
165
52.6
2.22
2.73
30- Day
Max.
.446
.476
7.51
110
35
1.48
1.82
Daily
Max.
1.34
1.43
22.5
330
105
4.43
5.46
30- Day
Hax.
(3)
(3)
.225
. __ tin Di
(3)
1.05
(3)
(3)
Daily
Max,
(3)
(3)
.646
scharge
(3)
3.01
(3)
(3)
30- Day
Max.
.0071
.0076
.12
of Poll
1.76
.561
.0236
.0291
Daily
Max.
.0129
.0138
.218
3.19
1.02
.0428
.0527
30-Day
Max,
.0116
.0124
.195
2.86
.911
.0384
.0473
Daily
Max.
.0237
.0252
.398
5.84
1.86
.0783
.0964
30-Day
Max.
.0165
.0176
.278
4.07
1.3
.0546
.0673
Daily
Max.
.0437
.0466
.736
10.8
3.44
.145
.178
pH
(2)
(2)
(2)
(2)
(2)
{2}
(2)
8.96
11.2
7.47 22.4 .224
.642
.12
.217 .194
.396 .276
.752 (2)
* All limitations are in units of kg/1000 kkg (Ih per minion Ih) of metal poured except for the Wet Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/6?.3 Sm3 {lb per billion SCF) of air scrubbed; in the case of the
former process segment, the limitations are in units of kg/1000 kkg (lb per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP)
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at NSPS for this process segment
(4) Applicable to plants that cast primarily malleable iron where greater than 3.557 tons of metal are poured per year and
to plants that cast primarily ductile or gray iron.
-------
a\
TABLE XII-2 (Continued)
NSPS LIMITATIONS* COVERING CONTINUOUS DIRECT DISCHARGES
Phenols(l)
D3jxpe_r Lead Zi nc
Subcategory and
Process Segment
Ferrousf 5}
Casting Cleaning
Casting Quench
Dust Col lection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Mold Cooling
30-Day
Max.
.67
.713
11.3
165
52.6
2.22
2.73
11.2
.536
.104
24.3
4.73
Daily
Max.
1.7
1.81
28.5
419
133
5.61
6.91
28.4
.67
.13
30.4
5.91
30-Day
Max,
.446
.476
7.51
110
35
1.48
1.82
7.47
.446
.0864
20.3
3.94
Daily
Max.
1.34
1.43
22.5
330
105
4.43
5.46
22.4
1.34
.259
60.8
11.8
30- Day
Max.
(3)
(3)
.225
Nn RT
— — — — Jiv U I
(3)
1.05
(3)
(3)
.224
(3)
.0026
.608
(3)
Dally
Max.
(3)
(3)
.656
scharge
(3)
3.01
(3)
(3)
.642
(3)
.0074
1.74
(3)
30- Day
Max.
.0071
.0076
.12
of Poll
1.76
.561
.0236
.0291
.12
.0187
.0036
.852
.166
Dally
Max.
.0129
.0138
.218
ii^sn^c «•<
3,19
1.02
,0428
.0527
,217
.0344
.0066
1,56
.304
30- Day
Max,
.0174
.0185
.293
4.3
1.37
.0576
.0709
.291
.0116
.0022
.527
.103
Daily
Max.
.0353
.0376
.593
8.7
2.77
.117
.144
.59
.0237
.0046
1.07
.209
30- Day
Max.
.025
.0266
.421
6.17
1.96
.0827
.102
.418
.0129
.0025
,588
.114
Daily
Max.
.0656
.0699
1.1
16.2
5.15
.217
.267
1.1
.0339
.0066
1.54
.3
M
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
(2)
* All limitations are in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Met Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 million Sm^ (lh per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/1000 kkg (Ib per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP)
(2) Within the range of 7.D to 10.0 at all times
(3) Not regulated at NSPS for this process segment
(5) Applicable to plants that cast primarily malleable iron where equal to or less than 3,557 tons of metal are poured per
year and to plants that cast primarily steel.
-------
TABLE XII-3
NSPS LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Suhcategory and
Proce_ss Segment
Alumi num
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hoi d Cool i ng
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
TSS_
30-Day "~ Daily
Max. Max.
12(4.8/x)
12(145/x)
12(.086/y)
12(1320/x)
12(.282/y)
12{61/x)
15(4.8/x)
15(145/x)
15(.086/y)
15(1320/x)
15(.282/y)
15(61/x)
°!L
30-D~ay
Max.
& Grease
Daily
Max.
15(12/x)
15(1. 45/x)
15(1. 04/x)
15(.036/y)
15{1320/x)
15(.468/y)
15(46. 3/x)
38(12/x)
38(1. 45/x)
38(l.rJ4/x)
38(.036/y)
38(1320/x)
38(,468/y)
38(46. 3/x)
10(1.45/x)
10(1.04/x)
30(12/x)
30(1.45/x)
30(1.04/x)
10(.036/y) 30(.036/y)
Mo Discharge of Pollutants-
10(1320/x) 30(1320/x)
10(.468/y)
10(46.3/x)
10(4.8/x)
10(145/x)
30(.468/y)
30(46,3/x)
30(4.8/x)
30(145/x)
10(.086/y) 30{.086/y}
-No Discharge of Pollutants-
10(1320/x) 30{1320/x)
10(.282/y)
10(61/x)
30(.?8Z/y)
30(61/x)
^henplsj 1)
30-Day ~ ~Daily
Max. Max,
(3)
(3)
0.3(1.04/x)
0.3{.036/y)
(3)
0.3(.468/y)
(3)
(3)
(3)
0.3(.086/y)
(3)
0.3(.282/y)
(3)
(3)
(3)
,86(1.04/x)
.86(.036/y)
~(3)~
.86(.468/y)
(3)
(3)
(3)
.86(.086/y)
'(3) " "
.86{.282/y)
(3)
All 30-Oay Haximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/ 1000 kkg (lb per million Ib) of pietal poured except for the Wet Sand Reclamation, Dust
of the latter two process
per billion SCF) of air
of kg/1000 kkg (Ib per
(1)
(2)
(3)
X =
Y =
Collection Scrubber, and Melting Furnace Scrubher process segments. In the case
segments, the annual average limitations are in units of kg/62,3 minion S^3 (ib
scrubbed; in the case of the former process segment, the limitations are in units
million lb) of sand reclaimed.
Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
Within the range of 7.0 to 10.0 at all times.
Not regulated at NSPS for this process segment.
Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific
pi ant.
Actual normalized process wastewater flow (in gallons per 1.000 SCF of air scrubbed) for the specific
pi ant.
-------
TABLE XII-3 (Continued)
NSPS LIMITATIONS* COVERING NON-CONTINUOUS DIRECT HASTEWATER DISCHARGES
Subcategory and
Pr_ocess_ Segment
Alumi num
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Hold Cooling
Copper
30-Day " "Daily 30-Day
Max. Max. Max.
Daily
Max.
30-Day
Max.
Daily
Max.
.42(12/x)
.42(1.45/x)
.42(1. 04/x)
.42(.036/y)
.42(1320/x)
.42{.468/y)
.42(46. 3/x)
.77(12/x)
.77(1. 45/x)
.77(1. 04/x)
.77{.036/y)
.77(1320/x)
.77(.468/y)
.77(46. 3/x)
.39(12/x)
.39(1. 45/x)
.39(1. 04/x)
.39{.036/y)
.39(1320/x)
.39(.468/y)
.39(46. 3/x)
.79(12/x)
.79(1. 45/x)
.79(1. 04/x)
.79{.036/y)
.79(1320/x)
.79{.468/y)
.79(46. 3/x)
.43(12/x)
.43(1. 45/x)
.43(1. 04/x)
.43(.036/y)
.43(1320/x)
.43(.468/y)
,43(46. 3/x)
1
1
1
1
1
1
1
!l4(1.45/x)
.14(1. 04/x)
.14(.036/y)
.14(1320/x)
.14(.468/y)
.14(46. 3/x)
(2)
(2)
(2)
(2)
(2)
(2)
,42(4.8/x)
.42(145/x)
.42(. 086/y)
.42(1320/x)
.42(.282/y)
.42{61/x)
.77(4.8/x)
.77(145/x)
.77(.086/y)
.77(1320/x)
,77(.282/y)
.77(61/x)
.26(4.8/x)
,26(145/x)
.26 (.086/y)
.26(1320/x)
!26(61/x)
.53{4-.8/x)
,53(H5/x)
.53 (.086/y)
rt-F Pnl 1 lit Jinf1 *
,53(1320/x}
.53(.282/y)
.53(61/x)
.29(4.8/x)
.29(145/x)
.29 (.086/y)
.29(1320/x)
.29(.282/y)
.29(61/x)
.76{4.B/x)
.76(145/x)
.76(. 086/y)
.76(1320/x)
.76(.282/y)
.76(61/x)
(2)
(2)
(2)
(2)
(2)
(2)
* All 30-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two
process segments, the annual average limitations are in units of kg/62.3 million Sm^ (Ib per billion
SCF) of air scrubbed; in the case of the former process segment, the limitations are in units of kg/1000
kkg (Ib per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at NSPS for this process segment.
X = Actual normalized process wastewater flow (in gallons per 1.000 pounds of metal poured) for the specific
pi ant.
Y = Actual normalizet) process wastewater flow (in gallons per l.DOO SCF of air scrubbed) for the specific
plant.
-------
TABLE XII-3 (Continued)
NSPS LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Subcategory and
Process Segment
Ferrous(4)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
T5S
30- Day
Max.
12{R.35/x)
12(5. 7/x)
12(.n9/y)
12(1320/x}
12(17. 7/x)
12(21- B/x)
Daily
Max.
15(5.35/x)
15(5. 7/x)
IS(.W/y)
15(1320/x)
15(.42/y)
15(17. 7/x)
15(21- B/x)
Oil S Gre
30- Day
Max.
10{5.3B/x)
10(5. 7/x)
Nn fH Jtj I lu I MC
in(i32n/x)
10(.42/y)
10(17. 7/x)
10(21. B/x)
ase
Daily
Max.
30(5. 35/x)
30(5. 7/x)
30(.n9/y)
n^ Pnl 1 ut ^n
wi i \J 1 iUbuii
30(1320/x)
30(.42/y)
30(17. 7/x)
30(21. 8/x)
Phenols(l)
30-Day Daily
Max. Max.
(3)
(3)
-3(.n9/y)
"(3)
•3(.42/y)
(3)
(3)
(3)
(3)
.36(.09/y)
"(3)~~~~
-86(.42/y)
(3)
(3)
12(89.5/2) 15(89.5/2) in(89.5/z) 30(89.F/z)
-3(89.F5/z) . 86(89.5/z)
{1}
(2)
(3)
X =
y =
z =
(lb per billion
in units of kg/1000
All 30-Day Maximum and Daily Maximum limitations are in rng/1 units. The annual average limitations are
in units of kg/1000 kkg (lb per million Ib) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two
process segments, the annual average limitations are in units of kg/62.3 million Sm3
SCF) of air scrubbed- in the case of the former process segment, the limitations are
kkg (Ib per million lb) of sand reclaimed.
Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
Within the range of 7.0 to 10.0 at all times.
Not regulated at KSPS for this segment.
Applicable to plants that cast primarily malleable Iron where greater than 3,557 tons of metal are
poured per year and to plants that cast primarily ductile or gray iron.
normalized process wastewater flow (in gallons per 1,000 pounds
Actual
plant.
Actual
plant.
Actual
of metal poured) for the specific
normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific
normalized process wastewater flow (in gallons per 1.000 pounds of sand reclaimed) for the
specific plant.
-------
to
o
NSPS
TABLE XI1-3 (Continued)
LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Sub category and
F^r qce s_s_ JSegm e nt
Ferrous{4)
Casting Cleaning
Casting Quench
nust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
Copper Lead
30-Day* " "" Daily 30-Day "
Hax. Max. Max.
Zinc
Daily
Max.
30-Day
Hax.
Daily
Max.
PH
.16(5.35/x)
.16(5. 7/x)
.16(.09/y)
,16(1320/x)
.I6(.42/y)
.16(17. 7/x)
. 16(21. S/x)
.29{5.35/x}
.29(5. 7/x)
.29{.09/y)
.29{1320/x)
.29{.42/y)
.29(17. 7/x)
.29C21.8/X)
,26(5.35/x)
.26(5. 7/x)
,26(.Q9/y)
.26fl320/x)
,26(.42/y)
.26(17. 7/x)
.26(21.8/x)
.53(5. 35/x) .37(5. 35/x)
,53(5. 7/x) .37(5.7/x)
,53(.09/y) .37(.09/y)
nf Pnl 1 1 it Ant c------ - -,
.53(1320/x) ,37(1320/x)
.98{5.35/x)
.98(5. 7/x)
,98(.09/y)
.98(1320/x)
(2)
(2)
(2)
(2)
.53(.42/y) .37{.42/y)
.53(17.7/x) .37(17,7/x)
.53(21.8/x) .37(21.8/x)
.98(.42/y) (2)
.98(17.7/x) (2)
.98(21.8/x) (2)
. 1.6(89.5/z) .29(89.5/2) .26(89.5/z) .53(89,5/z) .37(89.5/2) .98(89.5/z) (2)
are
(Ib per billion
in units of kg/1000
(1)
(2)
(3)
(4)
X =
Y =
Z =
All 3D-Day Maximum and Daily Maximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg Ob per million Ib) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of,the latter two
process segments, the annual average limitations are in units of kg/62.3 million
SCF) of air scrubbed: in the case of the former process segment, the limitations
kkg Ob per million Ib) of sand reclaimed.
Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
Within the range of 7.0 to 10.0 at all times.
Not regulated at NSPS for this segment.
Applicable to plants that cast primarily malleable iron where greater than 3,557 tons of metal are
poured per year and to plants that cast primarily ductile or gray iron.
Actual normalized process wastewater flow (in gallons per 1 ..ODD pounds of metal
plant.
Actual
plant.
Actual
poured) for the specific
normalized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific
normalized process wastewater flow (in gallons per 1,000 pounds of sand reclaimed) for the
specific plant.
-------
TABLE XI1-3 (Continued)
NSPS LIHITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Subcategory and
Process Segment
Ferrous(5)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Helting Furnace
Scrubber
Hold Cooling
Slag Oiiench
Wet Sand
Reel amation
Zi nc
Casting Quench
Die Casting
Helting Furnace
Scrubber
Mold Cooling
TSS
30-Day
Hax.
15(5. 35/x)
15(5. 7/x)
15f.09/y)
15(1320/x)
15(.42/y)
15(17. 7/x)
15(21.8/x)
15(89. 5/z}
15(5. 35/x}
15(1. 04/x)
15(.243/y)
15(47. 3/x)
Daily
_Hax_.
38(5. 35/x)
38(5. 7/x)
38(.09/y)
38(1320/x)
38(.42/y)
38(17. 7/x)
38(21.B/x}
38(89.5/z)
38(5,35/x)
38(1. OA/x)
38(.?43/y)
38(47. 3/x)
Oil S
30- Day'
_Max-_.
10(5. 35/x)
10(5. 7/x)
10(.09/y)
-No Dischar
10(1320/x)
10(.42/y)
10(17. 7/x)
10(21.8/x)
10(89.5/2)
10(5. 35/x)
10(1. 04/x)
10(.243/y)
10(47. 3/x)
Grease
"Da fly
Hax.
30(5, 35/x)
30(5. 7/x)
30(.09/y)
ge of Pollutan
30(1320/x}
30(.42/y)
30(17. 7/x)
30(21.8/x)
30(89. 5/z)
30(5. 35/x}
30(1. 04/x)
30( .243/y)
30(47. 3/x)
Phenol
30-Qa"y~~
Hax.
(3)
(3)
.3(.09/y)
tC-- -- ---
(3)
.3(.42/y)
(3)
(3)
.3(89.5/2}
(3)
,3(1.04/x)
,3(,243/y)
(3)
s{l)
Da'ily
_Hax_.
(3)
(3)
.86(.09/y)
(3)
.86(.42/y)
(3)
(3)
,86(89. 5/z)
(3)
.86(1. 04/x)
.86(. 243/y)
(3)
* All 30-Day Maximum and Daily Haximum limitations are in mg/1 units. The annual average limitations are
in units of kg/1000 kkg (lh per million Ib) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two
process segments, the annual average limitations are in units of kg/62.3 million Sm3 (lb per billion
SCF) of air scrubbed: in the case of the former process segment, the limitations are in units of kg/1000
kkg (Ib per million lb) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoarrtipyrene method (4AAP).
(2) Within the range of 7.0 to 10.0 at all times.
(3) Not regulated at NSPS for this process segment.
(5) Applicable to plants that cast primarily malleable iron where equal to or less than 3.557 tons of metal
are poured per year and to plants that cast primarily steel.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific
plant.
Y = Actual normalized process wastewater flow {in gallons per 1,000 SCF of air scrubbed) for the specific
plant.
I - Actual normalized process wastewater flow (in gallons per 1,000 pounds of sand reclaimed) for the
specific plant.
-------
Ul
ro
ro
NSPS
TABLE XI!-3 (Continued)
LIMITATIONS* COVERING NON-CONTINUOUS DIRECT WASTEWATER DISCHARGES
Subcategory and
Process Segment
Ferrous(B)
Casting Cleaning
Casting O'Jeneh
Dust Collection
Scrubber
firi ndi ng Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reelamation
Zinc
Casting Quench
Die Castng
Melting Furnace
Scruhber
Hold Cooling
Copper
30-Day"Dally
Max. Max.
Lea_d
30-Day " " Daily
Max. Max.
Zinc
30-Day " Daily
Max. Max.
pH
.16(5. 35/x)
.16(5. 7/x)
.16(.09/y}
.16(1320/x)
.16f.42/y)
.16(17. 7/x)
.16(21 .8/x)
.29(5. 35/x)
,29(5. 7/x)
.29(.D9/y)
.29(!320/x)
.29(.4?/y)
.29(17. 7/x)
.29(21. 8/x)
.39(5, 35/x)
.39(5. 7/x)
.39(.0i/y)
NA FH <£r"h;aif no
nu ijj.>v,iiai yc
.39(1320/x)
,39(.42/y)
,39(17. 7/x)
.39(2l.8/x)
.79(5.35/x) .56(5.35/x)
.79(5.7/x) .56(5,7/x)
.79(.09/y) ,56{.09/y)
of Pollutants -
.79(1320/x) .56(1320/x)
,79{.42/y) .56(.42/y)
.79(17.7/x) .56(17.7/x)
.79(21.8/x) .56(21.8/x)
1.47(5.35/x) (2)
1.47(5.7/x) (2)
1.47(.09/y) (2)
1.47(I320/x) (2)
1.47(.42/y) (2)
1.47(17.7/x) (2)
1.47(21.8/x) (2)
.16(89,5/1) .29(89.5/2) .39(89.5/2) .79(89.5/z) .56(39.5/2) 1.47(89.5/z) (2)
.42(5.35/x)
.42(1.04/x)
.42(.243/y)
.42(47.3/x}
.77(5.35/x) .26(5.35/x)
.77(1.04/x) .26(1.04/x)
.77(.243/y) ,26(.243/y)
,77(47.3/x) .26(47.3/x)
.53(5.35/x)
.53(1.04/x)
.29(5.35/x)
.29(1.04/x)
.53(.243/y) .29{.243/y)
.53(47,3/x) .29(47.3/x)
.76(5.35/x) (2)
.76(1.04/x) (2)
,76(.243/y) (2)
.76(47.3/x) (2)
* All 30-Day Maximum and Daily Maximum limitations art* In mg/1 units. The annual average limitations are
In units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation, Dust
Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two
process se-gments, the annual average limitations ire in units of kg/62.3 million SirP (1b per billion
SCF) of air scruhbed; in the case of the former process segment, the limitations are in units of kg/1000
kkg (Ib per million Ib) of sand reclaimed.
(1) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(2) Within the range of 7.0 to 10,0 at all times.
(3) Not regulated at NSPS for this process segment.
(B) Applicable to plants that cast primarily malleable iron where equal to or less than 3,557 tons of metal
are poured per year anri to plants that cast primarily steel.
X = Actual normalized process wastewater flow (in gallons per 1,000 pounds of metal poured) for the specific
plant.
Y = Actual nomialized process wastewater flow (in gallons per 1,000 SCF of air scrubbed) for the specific
plant.
Z = Actual normalized process wastewater flow (in gallons per 1,000 pounds of sand reclaimed) for the
specific plant.
-------
SECTION XIII
PRETREATMENT STANDARDS
INTRODUCTION
Section 307(b) of the Clean Water Act requires EPA to promulgate
pretreatment standards for existing sources (PSES). These
standards must be achieved within three years of promulgation.
PSES are designed to prevent the discharge of pollutants which
pass through, interfere with, or are otherwise incompatible with
the operation of publicly owned treatment works (PQTW). The
legislative history of the Clean Water Act of 1977 indicates that
pretreatment standards are to be technology-based, analogous to
the best available technology.
Section 307(c) of the Act requires EPA to promulgate pretreatment
standards for new sources (PSNS) at the same time that it
promulgates NSPS. New indirect discharging facilities, like new
direct discharging facilities, have the opportunity to
incorporate the best available demonstrated technologies,
including process changes, in-plant controls, and end-of-pipe
treatment technologies, and to use plant site selection to ensure
adequate treatment system installation.
General Pretreatment Regulations applicable to all existing and
new source indirect dischargers appear in 40 CFR Part 403.
This section describes the treatment and control technologies
that form the basis of pretreatment standards to control process
wastewater discharges from existing sources and new sources, and
describes the calculation of mass discharge standards of
regulated pollutants for existing and new sources, based on the
described control technologies.
TECHNICAL APPROACH TO ESTABLISHING PRETREATHENT STANDARDS
Before finalizing pretreatment standards applicable to the metal
molding and casting industry, the Agency examined whether the
pollutants discharged by the industry pass through the POTW or
interfere with the POTW operations or its chosen sludge disposal
practices. In determining whether pollutants pass through a
POTW, the Agency compares the percentage of pollutant removed by
a POTW with the percentage removed by the application of BAT
level treatment at indirect discharge facilities. A pollutant is
considered to pass through the POTW when the average percentage
removed nationwide by a well-operated POTW meeting secondary
treatment requirements is less than the percentage removed upon
compliance with PSES analagous to BAT level treatment.
523
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This approach to the definition of pass through satisfies two
competing objectives set by Congress: that standards for indirect
dischargers be equivalent to standards for direct dischargers,
while, at the same time, that the treatment capability and
performance of the POTW be recognized and taken into account in
regulating the discharge of pollutants from indirect dischargers.
Rather than compare the mass or concentration of pollutants
discharged by the POTW with the mass or concentration discharged
using BAT level treatment, the Agency compares the percentage of
the pollutants removed by the application of BAT level treatment.
The Agency takes this approach because a comparison of the mass
or concentration of pollutants in a POTW effluent with pollutants
in an industrial effluent would not take into account the mass of
pollutants discharged to the POTW from nonindustrial sources nor
the dilution of the pollutants in the POTW effluent resulting
from the addition of large amounts of nonindustrial wastewaters.
PASS THROUGH ANALYSIS
As explained in Sections X and XII, EPA has established BAT
effluent limitations guidelines and NSPS controlling the
following toxic and nonconventional pollutants: copper, lead,
zinc, and total phenols. Additionally, as stated in Section X,
EPA found treatable concentrations of toxic organic pollutants in
raw wastewaters for 22 process segments. They are:
Aluminum Subcategory;
Copper Subcategory:
Ferrous Subcategory:
Zinc Subcategory:
casting quench
die casting
dust collection scrubber
investment casting
melting furnace scrubber
mold cooling
casting quench
dust collection scrubber
investment casting
melting furnace scrubber
mold cooling
casting quench
dust collection scrubber
investment casting
melting furnace scrubber
mold cooling
slag quench
wet sand reclamation
casting quench
die casting
melting furnace scrubber
mold cooling
524
-------
This above list includes eight process segments where the control
of TTO was not specifically indicated in the March 20, 1984
Notice of Availability. Control of TTO in these additional
process segments is being required for the following reasons.
In response to public comments on the Agency's development of raw
waste loads, EPA has reviewed and re-evaluated its raw waste data
base. All sampling data have been normalized on the basis of the
mass of pollutant generated per mass of metal poured or sand
reclaimed or the volume of air scrubbed. The mass of pollutant
generated was calculated on the basis of the production or air
flow at each metal molding and casting plant sampled. The
normalized pollutant mass generation rates were then averaged to
determine an average process segment mass generation rate for
each pollutant detected. At the completion of this reevaluation,
the Agency identified two additional process segments with
priority organic pollutant loads that warranted control through
standards on TTO.
In addition, when the Agency considered the transfers of raw
waste data discussed in Section V, it determined that organic
priority pollutants should be controlled through standards on TTO
in six process segments where transferred organics data indicated
treatable levels of organics would be present. All data
transfers have been made between similar process segments where
pollutant loads/ including priority pollutant organics, are
introduced into the wastewater by the same mechanism. Therefore,
the Agency expects the levels of priority organic pollutants in
the segments to which data transfers have been made to be the
same as in the process segments from which the data originated.
EPA has not established BAT effluent limitations guidelines for
toxic organic compounds because the Agency determined that
compliance with the BPT effluent limitations guidelines and NSPS
for oil and grease provides effective removal of toxic organic
compounds. To conduct its analysis of pass through of TTO, EPA
determined the levels of TTO that would remain after the
application of BAT level treatment in each of the 22 process
segments where TTO is found at treatable levels.
EPA began by defining TTO separately for each of the 22 process
segments to include only those toxic organic pollutants that were
found at treatable concentrations in each process segment. EPA
then determined the TTO treatment effectiveness concentrations
attainable by the application of the best available technology
economically achievable. As explained in detail in Section VII,
EPA determined the treated effluent concentrations of various
individual toxic organic pollutants based on the removal
capability of four plants employing effective oil and grease
removal technology. For the toxic organic pollutants that were
not detected in raw wastewaters of the four plants, EPA estimated
treatability concentrations by dividing all pollutants for which
data were available into groups of pollutants with similar
octanol/water partition coefficients. Organic pollutants for
which sampling data were not available were assigned to one of
525
-------
the groups depending on their partition coefficient and were
assumed to have a treatability concentration equal to the mean
effluent concentration of all pollutants in the group. For some
pollutants, neither sampling data nor literature values for
partition coefficients were available. In such cases, estimates
were calculated using a parallel method based on the compound's
solubility in water.
The TTO treatment effectiveness concentrations were derived by
starting with the list of toxic organic pollutants in each
process segment which were present above treatable
concentrations. The treated effluent concentrations for each of
the toxic organic pollutants were summed for each process segment
to determine the long-term average treated effluent concentration
for all of the toxic organic pollutants found in raw wastewater
above treatable levels. A list of those toxic organic pollutants
included as TTO for each process segment is attached as Appendix
A.
Using the TTO treatment effectiveness concentrations and the flow
basis of BAT/NSPS for each of the 22 process segments, EPA
calculated long-term average TTO treated effluent loads
representative of the application of the technology that forms
the basis of BAT/NSPS. Using this information and the copper,
lead, zinc, and total phenols long-term average treated effluent
loads that form the basis of the BAT effluent limitations
guidelines and NSFS, EPA calculated the percentage reductions of
lead, copper, zinc, total phenols, and TTO that would result if
all indirect dischargers were required to meet the BAT effluent
limitations guidelines. These removals are shown on Table XIII-
1.
The options considered for PSES are the same as the BAT options
discussed in Section X. Additionally, as explained in Section
XII, EPA established NSPS for the metal molding and casting
category equal to the BAT effluent limitations guidelines.
Therefore, the options considered for PSNS are also the same as
the BAT options discussed in Section X.
As shown in Table XIII-1, the average removal of each of these
pollutants at BAT level treatment for each of the metal
subcategories was greater than the POTW removals. Accordingly,
the Agency has concluded that these pollutants pass through POTWs
and thus must be regulated under PSES. In addition, since toxic
metals are not degraded in the POTW (they either pass through or
are removed in the sludge), their presence in the POTW sludge may
limit a POTWs chosen sludge disposal method.
POTW removal rates for these pollutants are also shown on Table
XIII-1. They were determined by analyzing data from a study
conducted by the Agency at over 40 POTWs, (See Fate of Priority
Pollutants ill Publicly Owned Treatment Works, Final Report, EPA
440/1-82/303, September 1982.) The percent removals achieved at
POTWs were as follows: copper-58 percent, lead-48 percent, zinc-
65 percent, total phenols (4-AAP)-89 percent, and total toxic
526
-------
organics (TTO)-80 percent.
PSES AND PSNS OPTION SELECTION
EPA has promulgated PSES based on the application of technology
equivalent to BAT because, as discussed above, EPA has found that
Lhe pollutants regulated at BAT pass through POTWs. With the
following exceptions, PSES are based on the application of high
rate recycle with lime and settle treatment plus filtration. As
for BAT, EPA has based PSES on recycle, lime and settle for all
plants with indirect discharge in the aluminum subcategory, the
ferrous subcategory where steel is the primary metal cast, and
for the relatively small plants (those that pour less than 3,557
tons per year) in the ferrous subcategory which cast primarily
malleable iron. As for BAT, EPA is not establishing PSES for
plants in the magnesium subcategory because the economic impact
analysis indicates that the regulation is not economically
achievable for the magnesium subcategory. Magnesium subcategory
plants are subject to the General Pretreatment Regulations (40
CFR Part 403). Finally, the Agency's economic impact analysis
indicates that for small plants in the ferrous subcategory which
cast primarily gray iron and pour less than 1,784 tons of metal
per year, the cost of complying with pretreatment standards based
on recycle, lime and settle, and filtration is not economically
achievable. Therefore, PSES for these small gray iron plants is
based on recycle, lime and settle.
As explained in Section XII, NSPS are equal to the BAT effluent
limitations guidelines for the metal molding and casting
category. For this reason and for the reasons explained above,
EPA has established PSNS equal to PSES.
REGULATED POLLUTANT PARAMETERS
EPA has established PSES and PSNS controlling all toxic and
nonconventional pollutants regulated at BAT and NSPS that EPA
found to pass through POTWs. These are: zinc, copper, lead, and
total phenols. Additionally, as explained previously in this
section, EPA determined that toxic organic pollutants discharged
by metal molding and casting plants in all four subcategories are
likely to pass through POTWs. Thus, EPA has established
pretreatment standards controlling total toxic organic (TTO)
pollutants for the 22 process segments where toxic organic
pollutants were found at treatable concentrations in raw waste
dischargers.
The analysis of wastewaters for toxic organcs is costly and
requires sophisticated equipment. Therefore, the Agency has
included in the final regulations an alternate monitoring
paramater for TTO; the alternate parameter is oil and grease.
Data indicate that the toxic organics are more soluble in oil and
grease than in water, and that removal of oil and grease will
substantially remove the toxic organics. Additionally, the TTO
standard is based on the application of oil and grease removal
technology. If oil and grease is controlled at the regulated
527
-------
level, compliance with the TTO pretreatment standard is
established.
PSES/PSNS FLOW
As explained previously, EPA established the flow bases of BPT on
the lowest flow rates that the Agency believes were generally
achievable for each subcategory segment. Accordingly, as
explained in Sections X and XII, the flow bases of BAT and NSPS
are the same as for BPT. Thus, the flow bases of BPT also form
the bases of PSES/PSNS and are shown on Table XIII-2.
PSES/PSHS EFFLUENT STANDARDS
PSES are identical to PSNS because BAT effluent limitations
guidelines are equal to NSPS.
PSES/PSNS, established on a mass basis (mass of pollutant allowed
to be discharged per mass of metal poured, mass of sand
reclaimed, or volume of wet scrubber air flow), are presented in
Table XIII-3. EPA established mass-based pretreatment standards
because high rate recycle will reduce significantly the quantity
of pollutants discharged to POTWs from existing and new sources.
These standards were calculated for each regulated pollutant in
each process segment as follows: the PSES/PSNS normalized flow
for each discharge segment (see Table XIII-2) was multiplied by
the one-day maximum and by the maximum monthly average treatment
effectiveness concentrations (see Tables VII-12 and VII-14J
corresponding to the PSES/PSNS technology option selected for
each subcategory. As explained in Section VII, the maximum
monthly average treatment effectiveness concentration is based on
the average of 10 samples over the period of a month.
The Agency has considered the time for compliance with PSES. Few
of the plants in this industry with indirect discharge have
installed and are operating properly the technology necessary for
complying with PSES. Many plants in this and other industries
will be procuring engineering services and installing treatment
equipment utilized as model technologies for these regulations.
This may result in delays in engineering design, equipment
ordering and delivery, installation, start-up, and operating
these systems. For these reasons, the Agency has decided to
establish the PSES compliance date for all facilities at three
years from the date of promulgation. PSNS must be attained
immediately upon operation of the new indirect discharging
source.
Municipal authorities also may elect to establish concentration-
based pretreatment standards. They may do so provided the
concentration-based standards are equivalent to the mass-based
standards provided in Table XIII-3. Equivalent concentration
standards may be established by multiplying the mass standards
included in the Table XIII-3 by an appropriate measurement of
average production, raw material usage, or air flow (kkg of metal
poured, kkg of sand reclaimed, or standard cubic meters of air
528
-------
scrubbed) and dividing by an appropriate measure of average
discharge flow to the POTW, taking into account the proper
conversion factors to ensure that the units (mg/1) are correct.
COST OF APPLICATION AND EFFLUENT REDUCTIONS BENEFITS
Implementation of PSES will remove a total of 1,290,000 kg/yr
(2,845,000 Ibs/yr) of toxic metal and toxic organic pollutants
from wastewaters as currently discharged from indirect
discharging plants. Compliance with PSES will require a total
investment cost (beyond equipment in place) of $46.7 million, and
a total annualized cost of $21.5 million {1985 dollars). The
Agency has concluded that the PSES are economically achievable
for the metal molding and casting point source category.
EPA anticipates that new metal molding and casting plants subject
to PSNS that use wet scrubbing devices will remove toxic metal
and toxic organic pollutants at approximately the same rates as
will be removed by existing sources subject to PSES. Costs for
new sources employing wet scrubbers are also expected to be
comparable to those incurred by existing sources, although some
piping and retrofit costs (e.g., stream segregation) will not be
incurred by new source indirect discharging plants. If dry
scrubbers are used, both costs and pollutant removals will be
reduced considerably.
NON-WATER QUALITY ASPECTS OF PSES/PSNS
The following are the non-water quality environmental impacts
(including energy requirements) associated with PSES/PSNS:
Air Pollution
Application of the technologies that form the basis of PSES and
PSNS will not create any substantial air pollution problems.
Minor very localized air pollution emissions currently exist in
the ferrous casting subcategory where wastewaters are used to
quench the hot slag generated in the melting process. Also water
vapor containing some particulate matter is released from the
cooling tower systems used in the casting quench and mold cooling
process segments. However, none of these conditions currently
are considered significant and no significant future impacts are
expected as the result of PSES/PSNS.
Solid Waste
EPA estimates that the application oE the technologies that form
the basis of PSES will increase the quantity of sludges that must
be landfilled by metal molding and casting plants by about
442,000 kkg (486,000 tons) per year beyond current levels. In
addition, about 7,800 kkg (8,600 tons) per year of oily waste
will be generated beyond current levels. As explained in Section
VIII of this document, the Agency examined the solid wastes that
would be generated by metal molding and casting processes using
the model treatment technologies and has concluded that they are
529
-------
not hazardous under Section 3001 of the Resource Conservation and
Recovery Act {RCRA). Even though metal molding and casting
wastes are not identified as hazardous, they still must be
disposed of in a manner that will not violate the open dumping
prohibition of section 4005 of RCRA.
EPA anticipates that new metal molding and casting plants subject
to PSNS that use wet scrubbing devices will generate treatment
system sludges at approximately the same rates as will be
generated by existing sources subject to PSES. If dry scrubbers
are used, the quantity of treatment system sludges to be disposed
will be reduced considerably.
Consumptive Water Loss
EPA estimates that the evaporative water losses from the recycle
systems that the Agency projects will be used to comply with the
final PSES will be less than about 0.1 percent of the water
losses that now occur from the air pollution control scrubbers
used extensively throughout this industry. Therefore, compliance
with PSES/PSNS is not expected to result in a significant
consumptive water loss.
Energy Requirements
EPA estimates that compliance with PSES by indirect dischargers
will result in a total incremental electrical energy consumption
of 17 x 10 ° kilowatt-hours per year. This is an energy
increase of 0.06 percent over the 31.3 x 10^ kilowatt-hours
used in 1978 for production purposes.
The energy requirements for PSNS are estimated to be similar to
energy requirments for PSES on a per plant basis. More accurate
estimates are difficult to make because projections for new plant
construction are variable. It is estimated that new plants will
design, wherever possible, production techniques and air
pollution control devices that either require less water than
current practices or require no water such as dry air pollution
control devices. In these instances, less energy will be
required for water pollution control because less wastewater
would require treatment.
530
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TABLE XIII-1
PASS-THROUGH ANALYSIS
$ubjc_atiegory
Aluminum
Copper
Ferrous
Zinc
Cqpjjerl
94
99
99
99+
Lead2
97
98
99+
99+
lisc.3'
99
99
99+
99+
lota]_Pher
99+
99
99+
99
no5
99+
82
99
99+
1 POTW removal = 58%
2 POTW removal = 48%
3 POTW removal = 65%
4 POTW removal = 89%
5 TTO removal
80%; this figure assumes that substantial quantities of toxic
volatile organic pollutants that are reduced after the application
of biological treatment in a POTW are "removed." Considerable
evidence shows that a significant fraction of the volatile organic
compounds are air stripped and not removed. This 80 percent
figure would be substantially lower if credit were not taken for
volatile compounds that are air stripped rather than biodegraded.
531
-------
Table XIII-2
APPLIED FLOW RATES, RECYCLE RATES, AND DISCHARGE RATES THAT FORM THE BASIS
OF PSES AND PSNS
/f ro
Al urn in urn
Casting Cleaning
Casting Quench
l)je Casting
Dust Collection Scrubber
Grinding Scrubber
Investment Casting
He]ting Furnace Scrubber
Hold Cooling
Copper
Casting Quench
Dip-eel Chill Casting
Dual Collection Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace Scrubber
Ho]J Cool 5ng
{•'err on a
Casting Cleaning
Cast ing Quench
Uuat Collection Scrubber
<>ritnlliiK Scrubber
Investment Cabling
Mi: [1. f Ji(! l-tifiiiice .'}C:riii>t><:
Production
Normalized
Applied FlPR Bate
180 gal/ton
H5 gal/ton
11.4 gal/ton
1.78 gal/1,000 SCF
0.065 gal/1,000 SCF
17,600 gal/ton
11.7 gal/1,000 SCF
1,850 gal/ton
478 gal/ton
5,780 gal/ton
H.29 gal/1,000 SCF
0.111 gal/1,000 SCF
17,600 gal/ton
7.0« gal/1,000 SCF
2,150 gal/ton
213 gal/ton
571 gal/ton
3.0 gal/I,000 SCF
3.17 gal/1,000 SCF
17,600 ga I/tori
10.5 gal/1,000 SCF
Production
Normalizing Recycle
Parameter Rate
ton of metal poured 951
ton of metal poured 981
ton of metal poured 951
1,000 SCF of air 98J
flow through the
scrubber
1,000 SCF of air 1001
flow through the
scrubber
ton of metal poured 851
1,000 SCF of air 96»
flou through the
scrubber
ton of metal poured 95J
ton of metal poured 981
ton of metal poured 951
1,000 SCF of air 9BJ
Clou through the
scrubber
1,000 SCF of air 100J
flow through the
scrubber
ton of metal poured 85J
1,000 SCF of air 961
flow through the
scrubber
ton of metal poured 951
ton of wetal poured 95J
ton of metal poured 961
1,000 SCF of air 971
flou through the
scrubber
1,000 SCF of air 100J
flou through the
scrubber
ton of metal poured 851
1,000 SCF of air 96J
flou Uirotiglt I he
Production
Horrealized
24.0 gal/ton
2.90 gal/ton
2.07 gal/ton
O.OJ6 gal/1,000
SCF
0
2,640 gal/ton
0.168 gal/1,000
SCF
92.5 gal/ton
9.56 gal/ton
289 gal/ton
0.086 gal/1,000
SCF
2.6HO gal/ton
0.282 gal/1,000
SCF
122 gal/ton
10.7 gal/ton
11.
-------
Table XIII-2 (Continued)
APPLIED FLOW RATES, RECYCLE RATES, AND DISCHARGE THAT THE BASIS
OF AND
ififi-sa .at a lufi u I
terroua (Cunt.)
Hold Cooling
Slag Quench
Uet Sand Seel notation
Zino
Casting Quench
Die Casting
Melting Furnace Scrubber
Hold Cool lug
Production
Normal lied
if d Fl OM Kate
Production
Normalizing
Htcyele
Bate
70? gal/ton
727 gal/ton
895 gal/ton
533 gal/ton
11.it gal/ton
6.07 gal/1,000 SCF
1.B9G gal/ton
ton of netal poured 951
ton or aetal poured 94f
ton of aand reclaimed 80S
ton of aetal poured 981
ton of nets! poured 951
1,000 SCF of air 96t
flow through the
scrubber
ton of afcLal poured 95%
Production
Normalized
Qjacliarge Flow'
35.1 gal/ton
13.6 gal/ton
179 Hal/ton
10.? gal/ton
2.07 gal/ton
0.213 gal/1,000
SCF
91.5 gal/ton
for Bi
-------
t/l
LJ
ib
TABLE XI11-3
PSES AND PSNS LIMITATIONS* COVERING CONTINUOUS INDIRECT DISCHARGES
TTO
& Grease(IJ^ PhenoU{2) .c_°.P_Pe_p_ Lead Zinc
Subcategory and
Process Segment
Al uminum
Casting Cleaning
Casting Quench
Die Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Copper
Casting Quench
Direct Chill Casting
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
30 -Day
Max.
(4)
.0095
.01
.2
5.91
2.6
.304
.0109
(4)
.54
8.29
1.77
.14
Daily
Max.
(4)
.029
.0308
.613
18.1
7.97
.935
.0335
(4)
1.65
25.4
5.41
.488
30-Day
Max.
(4)
.121
.0864
3.00
110
39.1
3.86
.399
(4)
7.18
110
23.5
5.09
Daily
Max.
(4)
.363
.259
9.01
330
117
11.6
1.2
(4}
21.5
330
70.6
15.3
30-Day Daily
Max. Max.
(4) (4)
(4) (4)
.0026 .0074
.09 ,258
--No Discharge
(4) (4)
1.17 3.36
(4) (4)
(4) (4)
(4) (4)
.215 .617
--No Discharge
(4) (4)
.706 2.02
(4) (4)
30-Day Daily
Max,
.0421
.0051
.0036
.126
of Poll
4.63
1.64
.162
.0168
.506
.301
of Poll
4.63
.988
.214
Max.
.0771
.0093
.0066
.231
8.48
3.01
.297
.0307
.928
,553
8.48
1.81
.392
30-Day
Max.
.039
,0047
.0034
.117
4.3
1.52
.151
.0104
.314
.187
2.86
.612
.138
Daily 30-Day
Max , Max ,
.0791 .0431
.0096 .0052
.0068 .0037
.237 .129
8.7 4.74
3.09 1.68
.305 .166
.0211 .0116
.639 .35
.38 .208
5.84 3.19
1.25 .673
.27 .148
Daily
Max.
.114
.0138
,0098
.343
12.6
4.45
.44
.0303
.916
.545
8.37
1.79
.387
pH
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
* All limitations are in units of kg/1000 kkg (Ib per million Ib) of metal poured except for the Wet Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter t*o process
segments, the limitations are in units of kg/62,3 million Sm^ (Ib per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/1000 kkg (Ib per million Ib) of sand reclaimed.
(!) Alternate monitoring parameter for TTO.
(2) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(3) Within the range of 7.0 to 10.D at all times.
(4) Not regulated at PSES for this process segment.
-------
Ul
U
(Jl
Subcategory and
Prp_ce_s_s Segment
Ferrous{5)
Casting Cleaning
Casti ng Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
TABLE XIII-3 (Continued)
PSES AND PSNS LIMITATIONS* COVERING CONTINUOUS INDIRECT DISCHARGES
TTO
30-Day D'aily
Max. Max.
(4)
.00838
.664
4.3
2.73
.026
.00838
(4)
.0257
2.04
13.2
8.34
.0797
.0257
Oil & Grease(l)
30-Day
Max.
(4)
7.51
110
35
1.48
1.82
Daily
Max.
(4)
1.43
22.5
330
105
4,43
5.46
Phenol s(2)
Copper
30-Day Daily 30-Day Daily
Max. Max. Max. Max.
(4)
(4)
.225
(4)
1.05
(4)
(4)
(4)
(4)
.646
i scharge
(4)
3.01
(4)
(4)
.0071
.0076
.12
of Poll
1.76
.561
.0236
.0291
.0129
,0138
.218
3,19
1,02
,0428
.0527
Lead
30-Day" "D'aily
Max. Max.
.0116
.0124
.195
2.86
,911
.0384
.0473
,0237
.0252
.398
5.84
1.86
,0783
.0964
Zinc
30-Day
Max.
.0165
,0176
.278
4.07
1,30
,0546
.0673
Daily
Max.
.0437
,0466
.736
10.8
3,44
,145
.178
pJt
(3)
(3)
(3)
(3)
(3)
(3)
(3)
.386
1.18
7.47
22.4
.224
.642
.12
.217 .194
.396 .276
.732
(3)
* AH limitations are in units of kg/1000 kkg (Ib per million lb) of metal poured except for the Wet Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 million Sn)3 (1b per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/1000 kkg {lb per million Ib) of sand reclaimed,
(1) Alternate monitoring parameter for TTO.
(2) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(3) Within the range of 7.0 to 1D.O at all times.
(4) Not regulated at PSES for this process segment.
(5) Applicable to plants that are casting primarily ductile iron, to plants that are casting primarily malleable iron
where greater than 3557 tons of metal are poured per year, and to plants that are casting primarily gray iron where
greater than 1784 tons of metal are poured per year.
-------
TABLE XI11-3 (Continued)
PSES AND LIMITATIONS* COVERING CONTINUOUS INDIRECT DISCHARGES
TO OiJ_«__Gr_e_ase(l) Phenp_ljsJ_2) Copper Leaj Zinc
" " ' "
Subeategory and
Process Segment
Ferrotis(6)
Casting Cleaning
Casting Quench
Dust Collection
Scrubber
Grinding Scrubber
Investment Casting
Melting Furnace
Scrubber
Mold Cooling
Slag Quench
Wet Sand
Reclamation
Zinc
Casting Quench
Die Casting
Melting Furnace
Scrubber
Mold Cooling
30-Day
Max.
(4)
.00838
.664
4.3
2.73
.026
.00838
.386
.0304
.0064
1.29
.268
Daily
Max.
(4)
.0257
2.04
13.2
8.34
.0797
.0257
1.18
.093
.0196
3.95
.821
30-Day
Max.
(4)
.476
7.51
110
35
1.48
1.82
7.47
.446
.0864
20.3
3.94
Daily
Max.
(4)
1.43
22.5
330
105
4.43
5.46
22 A
1.34
.259
60.8
11.8
30-Day
Max.
(4)
(4)
.225
Daily
Max.
(4)
(4)
.656
—No Discharge
(4}
1.05
(4)
(4)
.224
(4)
.0026
.608
W
(4)
3.01
{4}
(4)
.642
(4)
.0074
1.74
(4)
30- Day
Max.
.0071
.0076
.12
of Pollut
1.76
.561
.0236
.0291
.12
.0187
.0036
.852
.166
Daily 30 -Day
Max. Max.
.0129 .0174
.0138 .0185
.218 .293
3.19 4.3
1.02 1.37
.0428 .0576
.0527 .0709
.217 .291
.0344 .0116
.0022
1.56 .527
.304 .103
Daily
Max.
.0353
.0376
.593
a. 7
2.77
.117
.144
.59
.0237
,0046
1.07
.209
30-Day
Max.
.025
.0266
.421
6.17
1.96
.0827
.102
.418
.0129
.0025
.588
.114
"""Daily
Max.
.0656
.0699
1.1
16.2
5.15
.217
.267
1.1
.D339
.0066
1.54
.3
pH
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
(3)
* All limitations are in units of kg/1000 kkg {lb per million lb) of metal poured except for the Wet Sand Reclamation,
Dust Collection Scrubber, and Melting Furnace Scrubber process segments. In the case of the latter two process
segments, the limitations are in units of kg/62.3 million Sm^ (lb per billion SCF) of air scrubbed; in the case of
the former process segment, the limitations are in units of kg/1000 kkg (Ib per million lb) of sand reclaimed.
(1) Alternate monitoring parameter for TTO.
(2) Total Phenols - Phenols as measured by the 4-aminoantipyrene method (4AAP).
(3) Within the range of 7.0 to 10.0 at all times.
(4) Not regulated at PSES for this process.
(6) Applicable to plants that are casting primarily steel, to plants that are casting primarily malleable iron where
equal to or less than 3557 tons of metal poured per year, and to plants that are casting primarily gray iron where
equal to or less than 1784 tons of metal are poured per year.
-------
SECTION XIV
ACKNOWLEDGEMENTS
All of the data gathering and engineering analyses which
supported the proposed regulations was performed by the NUS
Corporation. Subsequent to proposal, a major effort was
undertaken to verify a large number of comments regarding the
accuracy and completeness of the data base. Host of the
supplemental data gathering and engineering analyses also were
performed by the NUS Corporation, under the leadership of Mr. J.
Steven Paquette. Assisting Mr. Paquette with major contributions
were Mr. Joseph Boros, MS. Joan O. Knapp, Ms. Judith A. Delconte,
Mr. Raymond Hattras, and Mr. Michael Runatz. Assistance also was
provided by Mr. William Wall, Ms. Catherine Chambers, Mr. Robert
Griffin, Mr. Albert Finke, Mr, Patrick Falvey, and Mr. Kenneth
Wolfe. Clerical assistance was provided by Ms. Rane Wagner. The
dedication and sacrifices of this entire staff of NUS personnel
is appreciated.
Completion of the data gathering, engineering analyses, and
related support services was accomplished by the Radian
Corporation under the management of Mr. James Sherman and Mr.
Mark Hereth. Mr. Roy Sieber and Ms, Karen Christensen performed
these analyses and provided excellent and timely support in
completing final rulemaking and preparing this Development
Document. Word processing support was performed by Ms. Nancy
Johnson. Without these support services, this rulemaking would
not be possible.
The Agency wishes to express sincere thanks to the industry trade
associations which assisted in gathering and verifying an
extensive data base, and in providing constructive comments and
suggestions throughout the rulemaking process. Special thanks go
to Mr. Walter Kiplinger and the Cast Metals Federation; Mr.
William Huelsen, Mr. Gary Hosher and the American Foundryman's
Society; and Mr. Peter A.R. Findlay and the American Die Casting
Institute. The Agency also wishes to express sincere thanks to
the numerous metal molding and casting plant owners, managers,
and engineers who submitted data, responded to Data Collection
Portfolios and comment verification requests, provided
constructive comments, and graciously opened their plants to EPA
and contractor personnel.
A number of people within EPA made major contributions to this
rulemaking effort, including Ms. Eleanor Zimmerman, Mr. Rod
Frederick and their supporting contractor (Versar Corp.); Mr.
Mark Luttner and supporting contractor (Policy Planning and
Evaluation, Inc.); and Mr. Henry Kahn, Mr. Barnes Johnson, Mr.
Matthew Hnatov and supporting contractor (JRB Associates, Inc.).
Ms. Ellen Siegler is specially acknowledged for her extensive
537
-------
efforts and major contribution to the integrity, readability, and
legal rationale of the preamble, regulations, this Development
Document, and the comment response documents. The deft guidance
and tireless efforts of Mr, Robert W. Dellinger were essential to
the successful culmination of this rulemaking effort. Also, Ms.
Wendy Smith was the major contributor to completion of the coment
response documents, and Dr. Frank Hund contributed extensively to
preparation of the preamble and regulations, and other parts of
the rulemaking package. The constant vigil of Mr. Edward Dulaney
was essential to compiling and making available the extensive
record for this rulemaking, as well as working with NUS
Corporation and Radian Corporation, assisting in the data
gathering and review process, and many other important support
tasks. Finally, word processing for the preamble, regulations,
Development Document, and comment response documents was
performed by Ms. Carol Swann. Her personal sacrifices and long
hours made possible the completion of this rulemaking under
stringent deadlines, and the availability of this high quality
document.
538
-------
SECTION XV
REFERENCES
Bader, A.J., "Waste Treatment for an Automated Gray and Nodular
Iron Foundry", Proceedings of the Industrial Waste Conference?
22nd, Purdue University, pp. 468-476 (1967).
Beck, A.G., "An Instrument Method for Determination of Residual
Permanganate and Permanganate Demand", Water and Wastes
Engineering, pp. 42-43 (December 1968).
Building Construction Cost Data, 1978 Edition.
Chiou, Gary T., "Partition Coefficients of Organic Compounds in
Lipid-Water Systems and Correlation with Fish Bioconcentration
Factors", Env 1 ronmentajl Science and Technology, Volume 19, No. 1,
pp 57-62 (January, 1985).
"Chrysler's Winfield Foundry Solves Pollution Problem", Foundry,
97, pp. 612, 167-169 (September, 1969).
"Cupola Emission Control", Engles and Weber, 1967.
"Cupola Pollution Control at Unicast", Foundry, 98, pp, 240, 242
(April, 1970).
Deacon, J.S. "In Defense of the Wet Cap", Modern Casting, pp. 48-
49 (September, 1973).
Eckenfelder, W. Wesley, Industrial Water Pollution Control,
"Emissions Control System is Based on Impingement", Foundry, 101,
N. 9, pp. 108-110 (September, 1973).
"1973 Outlook", Foundry (January, 1973).
"Foundries Look at the Future", Foundry (October, 1972).
Fox, L.L. and Merrick, N.J., "Controlling Residual
Polychlorinated Biphenyls in Wastewater Treatment through
Conventional Means", Proceedings of the 37th Industrial Waste
Conference May IjL, 12_, and 13, 1982. Purdue University West.
Ljafeyette, I rid i ana. Ann Arbor Science Publishers (1982),
Harn, R.K., Boyle, W.C., and Blaha, F.J., "Leachate and
Groundwater Quality in and Around Ferrous Foundry Landfills and
Comparisons to Leach Test Results". American Foundrymen's
Society, Des Plaines, Illinois. January, 1985.
"Inventory of Foundry Equipment", Foundry (May, 1968).
539
-------
"Iron Casting Handbook", Gray and Ductile Iron Foundries Society,
Inc., Cleveland, Ohio. 1971.
Jordan, J. W., Memorandum to Regional Permits Branch Chiefs:
Calculation of_ Production - Based Effluent Limits, Environmental
P r o tection Agency, Washington, D.C., December 1984,
Kanicki, D. "Water at Neenah Foundry*', Modern Casting, p. 44
(July, 1978).
Kearney, A.T. and Company, Inc., "Study of Economic Impacts of
Pollution Control on the Iron Foundry Industry", 1971.
Manual of Standard Industrial Classification, 1967
Menerow, N.L., Industrial Water Pollution.
"Metal Casting Industry Census Guide", Foundry (August, 1972).
Miske, Jack C,f "Environment Control at Dayton Foundry", Foundry,
98, pp. 68-69 {May, 1970).
Parsons, A., Chemical Treatment of_ Sewage and Indus t r la^ Wastes.
Peters, M. S., and Timmerhaus, K. D., Plant Design and Economics
for Chemical Engineers, Third Edition* McGraw Hill Book Company,
1980.
"Potassium Permanganate Frees Effluent of Phenols", Chemical
Processing, p. 22 (September, 1975).
"Richardson Rapid System", 1978-79 Edition, by Richardson
Engineering Services, Inc.
"Sand Reclamation - A Status Report of Committee 80-S", Moder n
Casting, Manual 79, pp. 60.
"Settling Basins Clean GM Foundry Water," Foundry, 97, p. 146
{February, 1969).
Spicher, R., and Skrinde, R., "Potassium Permangante Oxidation of
Organic Contaminants in Water Supplies", Journal of the AWWA.
{September, 1963).
Stewart, R., Oxidation Mechanisms - Applications to Organic
Chemistry, W.A. Benjamin, Inc., New York, 1964.
Throop, W., and Boyle, W., "Perplexing Foundry Phenols "American
Fgundrymen's Society Transactions, pp. 393-400 #75-38.
U.S. Department of Commerce, "Iron and Steel Castings, November
1984", Current Industrial Reports, ME33A{84)-11 (1984).
U.S. Department of Commerce, "Iron and Steel Foundries and Steel
Ingot Producers", Current Industrial Reports, (1971).
540
-------
U.S. Department of Commerce, "Iron and Steel Foundries and Steel
Ingot Producers, Summary for 1983", Current Industrial Reports,
ME33A(83}-13 (1983).
U.S. Department of Commerce, "Nonferrous Castings, November 1984"
Current Industrial Reports, ME33E{84)-11 (1984).
U.S. Department of Commerce, "Nonferrous Castings, Summary for
1983", Current Industrial Reports, ME33E(83)-13 (1983).
U.S. Department of Health, Education and Welfare, Public Health
Service Publication, #99-AP-40.
U.S. Environmental Protection Agency, Development Document for
Effluent Limitations Guidelines and Standards for the Iron and
Steel Manufacturing Point Source Category - Final, EPA
440/182/024, Washington, D.C., Hay 1982.
U.S. Environmental Protection Agency, Guidance Manual for
Implementing Total Toxic Organics (TTO) Pretreatment Standards,
Washington D,C., September 1985,
U.S. Environmental Protection Agency, Guidance Manual for the Use
of_ Production Based Pretreatment Standards and the Combined
Wastestream Formula, Washington D.C., September 1985.
U.S. Environmental Protection Agency, Sampling and Analysis of
Wastes Generated by_ Gray Iron Foundries, EPA 600/4-81-028,
Washington D.C., April 1981.
Wagner, A.J., "Grede's Wichita Midwest Division Honored for Top
Environmental Control Job", Modern Casting, 58, N.6, pp. 40-43
(December, 1970).
"Water Pollution From Foundry Wastes", American Foundrymen's
Society, 1967.
Waters, O.B., "Total Water Recycling for Sand System Scrubbers",
Modern Casting, pp. 31-32 (July, 1973).
Wiese-Nielsen, K,, "High Pressure Water Jets Remove Investment
Casting Shells", Foundry M/T, {September, 1977).
541
-------
-------
SECTION XVI
GLOSSARY
This section is an alphabetical listing of the technical terms
(with definitions) used in this document that may not be familiar
to the reader.
4-AAP Colorimetric Method
An analytical method used to detect and quantify total phenols
and total phenolic compounds. The method involves reaction with
the color developing agent 4-aminoantipyrine.
Acidity
The quantitative capacity of aqueous solutions to react with
hydroxyl ions. The acidity of a solution is measured by
titrating the solution with a standard solution of a base to a
specified end point. Acidity is usually expressed as milligrams
of calcium carbonate per liter.
Acrylic Res ins
Synthetic resins used as sand binders in core making. These
resins are formed by the polymerization of acrylic acid or one of
its derivatives using benzoyl peroxide or a similar catalyst.
The most frequently used starting materials for acrylic resins
include acrylic acid, methacrylic acid, or acrylonitrile.
Exposure of these binder materials to hot metal temperatures can
cause breakdown of the chemical bonds within the resin molecules
and subsequent generation of cyanide.
The Act
The Federal Water Pollution Control Act Amendments of 1972 as
amended by the Clean Water Act of 1977 (P.L. 92-500).
Agglomerate
The collecting of small particles together into a larger mass.
Air Setting Binders
Sand binders which harden upon exposure to air. Sodium silicate,
Portland cement, and oxychloride are the primary constituents of
such binders. Air setting binders that are composed primarily of
oxychloride contain up to 10 percent finely divided metallic
copper. The copper is added to off-set the effects of such
impurities as calcium oxide, calcium hydroxide, and calcium
silicate, which may be introduced during the blending of
oxychloride. These impurities otherwise would decrease mold
strength and durability.
543
-------
Alkyd Resin Binders
Cold set resins used in the formation of cores. This type of
binder is a three component system using alkyd-isocyanate, cobalt
naphthenate, and diphenyl methane di-isocyanate. Cobalt
naphthenate is the drier, and diphenyl methane di-isocyanate is
the catalyst. Exposure of these binders to hot metal
temperatures can cause the breakdown of these binder materials,
and the resulting degradation products might include
naphthalenes, phenols, and cyanides.
Alloy
A mixture having metallic properties, composed of two or more
chemical elements at least one of which is an elemental metal.
Alloying Element
An element added to a metal to effect changes in properties, and
which remains within the metal. The following is a list of
materials known to be used as alloying materials or additives in
foundry metals:
Aluminum
Beryllium
Bismuth
Boron
Cadmium
Calcium
Carbon
Cerium
Chloride
Amortization
Chromium
Cobalt
Columbium
Copper
Hydrogen
Iron
Lead
Lithium
Magnesium
Manganese
Molybdenum
Nickel
Nitrogen
Oxygen
Phosphorus
Potassium
Selenium
Silicon
Sulfur
Tantalum
Tin
Titanium
Tungsten
Vanadium
Zinc
Zirconium
The allocation of a cost over a specified period of time by the
use of regular payments. The size of the payments is based on
the principal, the interest charged, and the length of time over
which the cost is allocated.
Analytical Quantification Level
The analytical quantification level of a pollutant is the minimum
concentration at which concentrations of that pollutant can be
reliably measured.
Backwashing
The operation of cleaning a filter or column by reversing the
flow of liquid through it, thus washing out matter previously
trapped.
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Baghouse
An independent structure or building that houses fabric bag
filters, which are used to remove dust from air. A baghouse
usually incorporates fans and dust conveying equipment.
Batch Treatment
A waste treatment method where wastewater is collected over a
period of time, and the collected wastewater is treated in a tank
or lagoon prior to discharge. Wastewater collection may be
continuous when treatment is batch.
Bench-Scale Pilot Studies
Laboratory experiments providing data concerning the treatability
of a wastewater stream or the efficiency of a treatment process.
Bench-scale experiments are conducted using laboratory-size
equipment.
Best Available Dejnonstraj:ed Technology j_BDT)
The treatment technology upon which new source performance
standards are based, as defined by Section 306 of the Act.
Best Available Technology Economical 1 y Achievable (j3ATJ
The level of technology chosen as the basis for effluent
limitations, applicable to toxic and nonconventional pollutants,
to be achieved by July 1, 1984. BAT effluent limitations are
established based on the degree of effluent reduction that this
technology can attain. BAT limitations apply to industrial point
sources discharging to surface waters as defined in Section
301(b)(2)(E) of the Act.
Best Conventional Pollutant Control Technology JJBCT)^
The level of technology chosen as the basis for effluent
limitations, applicable to conventional pollutants, to be
achieved by July 1, 1984. BCT effluent limitations are
established based on the degree of effluent reduction that this
technology can attain, BCT limitations apply to industrial point
sources discharging to surface waters as defined in Section
301(b)(2)£E) of the Act.
Best Management Practices (BMP)
Regulations intended to control the release of toxic and
hazardous pollutants from plant runoff, spillage, leaks, solid
waste disposal, and drainage from raw material storage.
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Best Practicable Control Technology Currentlf Available (BPT
The level of technology chosen as the basis for effluent
limitations, applicable to toxic and nonconventional pollutants,
that was to have been achieved by July 1, 1977, BPT effluent
limitations are established based on the degree of effluent
reduction that this technology can attain. BPT limitations apply
to industrial point sources discharging to surface waters as
defined in Section 301(b)(l)(A) of the Act.
B_inder
A material, other than water, added to foundry sand to bind the
particles together, sometimes with the use of heat.
Biochemical Oxygen Demand (BODj_
The quantity of oxygen used in the biochemical oxidation of
organic matter under specified conditions for a specified time.
Blast Furnace
A shaft furnace in which solid fuel is burned with an air blast
to smelt ore in a continuous operation. Where the temperature
must be high/ as in the production of pig iron, the air is
preheated. Where the temperature can be lower, as in smelting
copper, lead, and tin ores, a smaller furnace is economical, and
preheating of the blast is not required.
Slowdown
The minimum discharge of circulating water from a unit operation
such as a scrubber for the purpose of discharging dissolved
solids or other contaminants contained in the water.
Borides
A class of boron-containing compounds, primarily calcium boride,
used as a constituent in refractory materials. Metallic
impurities that often accompany the use of these materials
include titanium, zirconium, hafnium, vanadium, niobium,
tantalum, chromium, molybdenum, tungsten, thorium, and uranium.
Bulk Bed Washer
A type of wet dust collector consisting of a bed of lightweight
spheres through which the dust laden air must pass while being
sprayed by water or another scrubbing liquor.
Carbon Reduction
The process of using the carbon of coke as a reducing agent in
the blast furnace.
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Catalysts
Materials that accelerate the setting of binders used in core and
mold formation. Phosphoric acid and toluenesulfonic acid are
common set catalysts. Exposure of residual catalyst materials in
the mold to hot metal temperatures could cause chemical breakdown
of these materials with the possible generation of free toluene.
Charcoal
A product of the destructive distillation of wood. Used as a
fuel and as a source of carbon in the foundry industry. Because
of the nature of the destructive distillation process, charcoal
may contain residuals of toxic pollutants such as phenol,
benzene, toluene, naphthalene, and nitrosamines.
Charge
The combination of liquid and solid materials fed into a furnace
for one cycle of its operation.
Chemical Oxygen Demand
A measure of the oxygen-consuming capacity of the organic and
inorganic matter present in the water or wastewater.
Chrome Sajvd .(_Chrome_-I_rgn_ Ore^
A dark material containing dark brown streaks with submetallic to
metallic luster. Usually found as grains disseminated in
perioditite rocks. Used in the preparation of molds.
Chromite Flour (see Chrome Sand aboye)
Chrome sand ground to 200 mesh or finer which can be used as a
filler material for mold coatings for steel castings.
Clar ification
The process of removing undissolved materials from a liquid,
specifically by sedimentation. A clarifier is a specialized
piece of equipment used for this purpose,
Classifier
A device that separates particles from a fluid stream by size.
Stream velocity is gradually reduced, and the larger sized
particles drop out when the stream velocity can no longer carry
them.
Cleaning Agents and Degreasers
Solvents used to clean oil and grease or dirt from the surface of
a metal. Common cleaning and degreasing agents include ethylene
dichloride, polychloroethylene, and trichloroethylene.
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Coagulant.
A compound which, when added to a wastewater stream, enhances
wastewater settleability. The coagulant aids in the binding and
agglomeration of the particles suspended in the wastewater.
Coatings ^ Corrosion Resistant
Generally alkyd or epoxy resins. See Alkyd Resin Binders and
Epoxy Resins. Applied to metal molds to prevent surface
corrosion.
Coke-Foundry
The residue from the destructive distillation of coal. A primary
ingredient in the making of cast iron in the cupola. Because of
the nature of the destructive distillation process and impurities
in the coal, the coke may contain residuals of toxic pollutants
such as phenol, benzene, toluene, naphthalene, and nitrosamines,
Coke-Pet roleum
Formed by the destructive distillation of petroleum. Like
foundry coke, petroleum coke can also be used for making cast
iron in the cupola.
Coke-Pitch
Formed by the destructive distillation of petroleum pitch. Used
as a binder in the sand molding process.
Cold-Set Resins
Resins that set or harden without the application of heat. Used
in foundry operations as sand binders.
Complete Recycle
The complete reuse of a stream, with makeup water added for
evaporation losses. There is no blowdown stream from a totally
recycled flow and the process water is not periodically or
continuously discharged.
Composite Samples
A series of samples collected over a period of time but combined
into a single sample for analysis. The individual samples can be
taken after a specified amount of time has passed (time
composited), or after a specified volume of water has passed the
sampling point (flow composited). The sample can be
automatically collected and composited by a sampler or can be
manually collected and combined.
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Consent Decree (Settlement Agreement)
Agreement between EPA and various environmental groups, as
instituted by the United States District Court for the District
of Columbia, directing EPA to study and promulgate regulations
for the toxic pollutants (NRDC, Inc. v. Train, 8 ERC 2120 (D.D.C.
1976), modified March 9, 1979, 12 ERC 1833, 1841).
Contact Water
Any water or oil that comes into direct contact with the metal
being cast, or with a mold that has been in direct contact with
the metal. The metal contacted may be raw material, intermediate
product, waste product, or finished product.
Continuous Treatment
Treatment of waste streams operating without interruption (as
opposed to batch treatment). Sometimes referred to as flow-
through treatment.
Contractor Removal
Disposal of oils, spent solutions, or sludge by a commercial
firm.
Conventional Pollutants
Constituents of wastewater as determined by Section 304(a){4) of
the Act, including but not limited to pollutants classified as
biological-oxygen-demanding, oil and grease, suspended solids,
fecal coliforms, and pH.
Coolants
Water, oil and air. Their use is determined by the extent and
rate of cooling desired.
Cooling Tower
A hollow, vertical structure with internal baffles designed to
break up falling water so that it is cooled by upward-flowing air
and the evaporation of water.
Cope
The top half of a two-piece sand mold.
Core
A very firm shape of sand used to obtain a hollow section in a
casting. The core is placed in a mold cavity to give interior
shape to the casting.
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Core Binders
Bonding and holding materials used in the formation of sand
cores. The three general types consist of those that harden at
room temperature, those that require baking, and the natural
clays. Binders that harden at room temperature include sodium
silicate, Portland cement, and chemical cements such as
oxychloride. Binders that require baking include the resins,
resin oils, pitch, molasses, cereals, sulfide liquor, and
proteins. Fireclay and bentonite are the natural clay binders.
Core Binder Accelerators
Used in conjunction with furan resins to cause hardening of the
resin-sand mixture at room temperature. The most commonly used
accelerator is phosphoric acid.
Core and Mold Washes
A mixture of various materials, primarily graphite, used to
obtain a better finish on castings, including smoother surfaces,
less scabbing and buckling, and less metal penetration. The
filler material for washes should be refractory type composed of
silica flour, zircon flour or chromite flour.
Core Oils
Used in oil-sand cores as a parting agent to prevent the core
material from sticking to the cast metal. Core oils are
generally classified as mineral oils (refined petroleum oils) and
are available as proprietary mixtures or can be ordered to
specification. Typical core oils have specific gravities of 0,93
to 0.965 and contain a minimum of 70 percent nonvolatiles at
1770C (3500F).
Crucible
A highly refractory vessel used to melt metals.
Cupola
A vertical shaft furnace consisting of a cylindrical steel shell
lined with refractories and equipped with air inlets at the base
and an opening near the top for charging fuel and melting stock.
Cyclones
A funnel-shaped device for removing particulates from air or
other fluids by centrifugal means.
Data Collection Portfolio {DCP)
The written questionnaire used to survey the metal molding and
casting industry.
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Casting
A casting process where molten metal is forced under high
pressure into the cavity of a metal mold,
Die Coatings
Oil containing lubricants or parting compounds such as carbon
tetrachloride, cyclohexane, methylene chloride, xylene and
hexamethylenetetramine. The coatings are used to prevent
castings from adhering to the die and to provide a casting with a
better finish. A correctly chosen lubricant will allow metal to
flow into cavities that otherwise cannot be filled,
Direct Chill Casting
A method of casting where the molten metal is poured into a
water-cooled mold. The base of this mold is the top of a
hydraulic cylinder that lowers the metal first through the mold
and then through a water spray and bath to cause solidification,
The vertical distance of the drop limits the length of the ingot.
This process is also known as semi-continuous casting.
Direct Discharger
Any point source that discharges to a surface water.
The lower half of a two-piece sand mold.
Drying Beds
Areas for the dewatering of sludge by evaporation and seepage.
Effluent
Wastewater discharged from a point source.
E£fluent Limitation
Any standard (including schedules of compliance) established by a
state or EPA on quantities, rates, and concentrations of
chemical, physical, biological, and other constituents that are
discharged from point sources into navigable waters, the waters
of the contiguous zone, or the ocean.
Electrode
Long cylindrical rods made of carbon or graphite used in electric
arc furnaces to conduct electricity into the metal charge.
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Res_iriS
Two-component resins used to provide corrosion resistant coatings
for metallic molds or castings. These materials are synthetic
resins obtained by the condensation or polymerization of phenol,
acetone, and epichlorohydrin (chloropropylene oxide). Alkyds,
acrylates, methacrylates, and allyls, hydrocarbon polymers such
as indene, coumarone and styrene, silicon resins, and natural and
synthetic rubbers all can be applied as additives or bases.
Polyamine and amine based compounds are normally used as curing
agents. Because of the temperatures to which these materials are
exposed, and because of the types of materials that are used to
produce many of the components of these materials, toxic
pollutants such as zinc, nickel, phenol, benzene, toluene,
naphthalene, and possibly nitrosamines could be generated,
Filter Cake
That layer of dewatered sludge removed from the surface of a
filter. Filters are used to reduce the volume of sludge
generated as a result of the waste treatment process.
Flash .ing
In die casting, the fin of metal that results from leakage
between the mating die surfaces.
Flask
A rectangular frame open at top and bottom used to retain molding
sand around a pattern.
FliOCgu la, t.1 on
The process by which particles agglomerate, resulting in an
increase in particle size and settleability.
Flux
A substance added to molten metal to help remove impurities and
prevent excessive oxidation, or promote the fusing of the metals.
Fujran Resin
A heterocyclic ring compound formed from diene and cyclic vinyl
ether. Its main use is as a cold set resin in conjunction with
acid accelerators such as phosphoric or toluene sulfonic acid for
making core sand mixtures that harden at room temperature.
Toluene could be formed during thermal degradation of furan
resins during metal pouring.
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Fujrfuryl Alcohol
A synthetic resin used to formulate core binders. The amount of
furfuryl alcohol used in the binder formulation depends on the
desired core strength. One method of formulating furfuryl
alcohol is by batch hydrogenation of furfuryl at elevated
temperature and pressure with a copper chromite catalyst.
Gas Chrgma_tography/Mas s Spectroscopy (GC/MS)
Chemical analytical instrumentation used for quantitative organic
analysis.
Gate
An entry passage for molten metal into a mold.
Gilsonite
A material used primarily for sand binders. It is one of the
purest natural bitumens {99.9 percent) and is found in lead
mines. Lead may be present as an impurity in Gilsonite.
Grab Sample
A single sample of wastewater taken without regard to time or
flow.
Gypsum Cement
A group of cements consisting primarily of calcium sulfate and
produced by the complete dehydration of gypsum. It usually
contains additives such as aluminum sulfate or potassium
carbonate. It is used in sand binder formulation.
Head
A large reservoir of molten metal incorporated into a mold to
supply hot metal to a shrinking portion of a casting during its
cooling stage.
Heat Treatment
Heating and cooling a solid metal or alloy in such a way as to
obtain desired conditions or properties. Heating for the sole
purpose of hot working is excluded from the meaning of this
definition.
Hydraulij: Cyj^lpne
A fluid classifying device that separates heavier particles
a slurry.
from
553
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Impingement
The striking of air or gas-borne particles on a wall or baffle,
Impr eg ria^tlng Compounds
Materials of low viscosity and surface tension, used primarily
for the sealing of castings. Polyester resins and sodium
silicate are the two types of materials used, Phthalic anhydride
and diallyl phthalate are used in the formulation of the
polyester resins.
Indirect Discharger
Any point
works.
source that discharges to a publicly owned treatment
Induction Furnace
A crucible surrounded by coils carrying alternating electric
current. The current induces magnetic forces into the metal
charged into the crucible. These forces cause the metal to heat.
Inductively-Coupled Argon Plasma Spectrophotometer (ICAP)
A laboratory device used for the analysis of metals.
In-Process Control Technology
Any procedure or equipment used to conserve chemicals and water
throughout the production operationsr resulting in a reduction of
the wastewater volume.
Investment Mold Materials
A broad range of waxes and resins including vegetable wax,
mineral wax, synthetic wax, petroleum wax, insect wax, rosin,
terpene resins, coal tar resins, chlorinated elastomer resins,
and polyethylene resins used in the manufacture and use of
investment molds. The presence of coal tar resins in investment
mold materials indicate the possible presence of toxic pollutants
such as phenol, benzene, toluene, naphthalene, and nitrosamines
as residues in the resins or as possible products of degradation
of these resins when subjected to heat.
Ladle
A vessel used to hold or pour molten metal.
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Binders
Additives incorporated into resin-sand mixtures to improve
surface finish and to eliminate thermal cracking during pouring.
Lignin is a major polymeric component of woody tissue composed of
repeating phenyl propane units. It generally amounts to 20-30
percent of the dry weight of wood. Phenol might be generated
during thermal degradation of lignin binders during metal
pouring.
Lubricants
Substances added to resin-sand mixtures to permit the easy
release of molds from patterns. Calcium stearate, zinc stearate
and carnauba wax are common lubricating agents.
Mica
A class of silicates with widely varying composition used in the
refractory making process. They are essentially silicates of
aluminum but are sometimes partially replaced by iron, chromium
and an alkali such as potassium, sodium or lithium.
Mold
A form made of sand, metal, or refractory material that contains
the cavity into which molten metal is poured to produce a casting
of definite shape and outline.
MOLDING
CO^__Mglding. The CO2 {carbon dioxide) molding
process uses sodium silicate binders to replace the
clay binders used in sand molds and cores. In the
CO2 process, a low-strength mold or core is made
with a mixture of sodium silicate {3-4 percent) and
sand. Carbon dioxide gas is passed through the sand,
causing the sodium silicate to develop a dry
compressive strength greater than 200 psi. Ready-to-use
cores and complete molds can be made quickly, with no baking
or drying needed. The high strength developed by the
CO2 process enables molds to be made and poured
without backup flasks or jackets.
Investment Casting. Casting metal into a mold produced by
surrounding (investing) an expendable pattern with a
refractory slurry that sets at room temperature. After the
mold has set, the wax, plastic or frozen mercury pattern is
removed through the use of heat. Also called precision
casting, or lost-wax process.
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No-Bake Molding. The process is of fairly recent {15 years)
origfn. The sand coating consists of a binder and catalyst?
their interaction results in a molded sand with high green
strength (over 200 psi}. No heat is required to set the
mold. The amount of sand used and the general form of the
molds are similar to green sand operations; however, the
high strength permits flask removal and mold pouring without
a jacket. The castings poured using this process have good
dimensional accuracy and excellent finish.
Permanent Mold Casting. Metal molding using molds that
consist of two or more metal parts, used repeatedly for the
production of many castings of the same form, The molten
metal enters the mold by gravity. Permanent mold casting is
particularly suitable for high-volume production of small,
simple cast-ings that have a uniform wall thickness and no
undercuts or intricate internal coring.
Plaster Mold Casting. Molding wherein a gypsum-bonded
aggregate flour in the form of a water slurry is poured over
a pattern, permitted to harden, and after removal of the
pattern, thoroughly dried. Plaster mold casting is used to
produce nonferrous castings that have greater dimensional
accuracy, smoother surfaces, and more-finely reproduced
details than can be obtained with sand molds or permanent
molds.
Shell Molding. Shell molding is a process in which a mold
is formed from a mixture of sand and a heat-setting resin
binder. The sand resin mixture is placed in a heated metal
pattern in which the heat causes the binder to set. As the
sand grains adhere to each other, a sturdy shell, which
becomes one half of the mold, is formed. The halves are
placed together with cores located properly, clamped and
adequately backed up, and then the mold is poured. This
process produces castings with good surface finish and good
dimensional accuracy while using smaller amounts of molding
sand.
New Source Performance Standards (NSPS)
Effluent limitations for new industrial point sources as defined
by Section 306 of the Act.
Ng-J3ake Binders
Sand binders that set without the addition of heat. Furan resins
and alkyd-isocyanate compounds are the two predominant no-bake
binders. Furan resins, as previously mentioned, are cyclic
compounds which use phosphoric acid or toluenesulfonic acid as
the setting agents.
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Nonconventional Pollutant.
Parameters selected for consideration in performance standards
that have not been previously designated as either conventional
or toxic pollutants.
Non-Water Quality Environmental Impact
The ecological impact as a result of solid, air, or thermal
pollution due to the application of various wastewater
technologies to achieve the effluent guidelines limitations.
Also associated with the non-water quality aspect is the energy
impact of wastewater treatment.
NPDES Permits
Permits issued by EPA or an approved state program under the
National Pollutant Discharge Elimination System, as required by
the Clean Water Act.
Off-Gases
Gases, vapors, and fumes produced as a result of metal molding
and casting operations.
Oil and Grease (Q&G)
Any material that is extracted by freon from an acidified sample
and that is not volatilized during the analysis, such as
hydrocarbons, fatty acids, soaps, fats, waxes, and oils.
Pattern
A form of wood, metal, or other material around which molding
material is placed to make a mold for casting metals.
El
The pH is the negative logarithm of the hydrogen ion activity of
a solution. The pH of a solution is an indication of its acidity
or alkalinity. Solutions with high pH values are considered
acidic; low pH values indicate alkalinity.
Phenolic Resins
Phenol formaldehyde resins - A group of varied and versatile
synthetic resins. They are made by reacting almost any phenolic
and an aldehyde. In some cases, hexamethylenetetramine is added
to increase the aldehyde content. Both types of materials are
used separately or in combination in the blending of commercial
molding materials. Due to the thermal degradation of phenolic
resins that may occur during metal pouring, phenol and
formaldehyde may be generated.
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Pitch Binde r s
Thermosetting binders used in core making. Baking of the sand-
binder mixture is required for evaporation-oxidation and
polymerization to take place.
Pollutant Parameters
Those constituents of wastewater determined to be detrimental to
human health or the environment.
Polymer ic Fj.occulajrt (Pp 1 ye lee tr ol y t e)
High molecular weight compounds which, due to their charges, aid
in particle binding and agglomeration,
Priority Pollutants
Those 129 pollutants included in Table 2 of Committee Print
number 95-30 of the "Committee on Public Works and Transportation
of the House of Representatives," subject to the Act.
Process Water
Water used in a production process that contacts the product, raw
materials, or reagents.
Production Normalizing Parameter (j>NP)
The unit of production specified in the regulations used to
determine the mass of pollution a production facility may
discharge.
PSES
Pretreatment standards (effluent regulations) for existing
sources applicable to indirect dischargers.
PSNS
Pretreatment standards (effluent regulations) for new snnrnps
applicable to new indirect dischargers.
Publicly Owned Treatment. Works JPOTW)
A waste treatment facility that is owned by a state or
municipality.
Quenchi ng
A process of inducing rapid cooling of a casting from an elevated
temperature, usually by sudden immersion in water.
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Quenching Oil
Medium to heavy grade mineral oils used in the cooling of metal,
Standard weight or grade of oil would be similar to standard SAE
60.
Recycle
Returning treated or untreated wastewater to the production
process from which it originated for use as process water,
Recuperator
A steel or refractory chamber used to reclaim heat from waste
gases.
Reduction
A reaction in which there is a decrease in valence, or electric
charge, resulting from a gain in electrons.
Reuse
The use of treated or untreated process wastewater in a different
production process.
Reverberatory Furnaces
Rectangular furnaces in which the fuel is burned above the metal
and the heat reflects off the walls and into the metal,
Riser
A reservoir of molten metal connected to the casting to provide
additional metal to the casting. Additional metal is required as
the result of shrinkage that occurs before and during
solidification,
Riser Compounds
Extra strength binders used to reduce the extent of riser
erosion. Such materials generally contain lignin, furfuryl
alcohol, and phosphoric acid.
Rosins, Natural
(Gum rosin, colophony, pine resin, common rosin) - A. resin
obtained as a residue from distillation of turpentine oil from
crude turpentine. Rosin is primarily an isomeric form of the
anhydride of abietic acid. It is one of the more common binders
in the foundry industry.
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Runner
A channel through which molten metal flows from one receptacle to
another. Runner is often used to refer to the portion of the
gate assembly that connects the riser with the casting.
Sand Binders
Binder materials are the same as those used in core making. The
percentage of binder may vary in core and molds depending on sand
strength required, extent of mold distortion from hot metal and
the metal surface finish required.
SaTd
Additlves
A mixture of sand, dicalcium silicate, water and wetting agents.
This combination is based on a process of Russian origin which
achieves a higher degree of flowability than either the
conventional sand mix or those with organic additives.
Usually refers to miscellaneous metal used in a charge to make
new metal.
Scjrujjber Liguor
The untreated wastewater stream produced by wet scrubbers
cleaning gases produced by metal manufacturing operations.
Seacoal
Finely ground bituminous coal used as an ingredient in molding
sands to control the thermal expansion of the mold, and to
control the composition of the mold cavity gas during pouring.
Shakeout
The operation of removing castings from the mold. A mechanical
unit is used to separate the mold material from the solidified
casting.
Shot Blast
A casting cleaning process employing a metal abrasive (grit or
shot) propelled by centrifugal or air force.
A product resulting from the action of a flux on the oxidized
non-metallic constituents of molten metals.
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Slag Quench
A process of rapidly cooling molten slag to produce a more easily
handled solid material. Usually performed by sudden immersion in
a water trough or sump.
Smarkel.
A pipe through the furnace roof, or an opening in a furnace roof,
used to withdraw the furnace atmosphere.
Sjgray Chamber
A large chamber in a flowing stream where water or liquor sprays
are introduced to wet the flowing gas.
A vertical channel from the top of the mold used to conduct the
molten metal to the mold cavity.
Subcategorization
The process of segmentation of an industry into groups of plants
for which uniform effluent limitations can be established.
igurjerriatjint
A liquid or fluid forming a layer above settled solids.
Surface Water
Any visible stream or body of water, natural or manmade. This
does not include bodies of water whose sole purpose is wastewater
retention or the removal of pollutants, such as holding ponds or
lagoons.
Surfactants
Surface active chemicals that tend to lower the surface tension
between liquids.
TappJ.ng
The process of removing molten metal from a furnace.
Thermoset Resins
Resins used as binding agents in molding sands. Thermoset resins
require the addition of heat in order to solidify and "set" the
mold.
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Total Dissolved Splidg (TDS)
Organic and inorganic molecules and ions that are in true
solution in the water or wastewater,
Total Orgarii£ Carbon (TOC)
A measure of the organic contaminants in a wastewater. The TOC
analysis does not measure as much of the organics as the COD or
BOD tests, but is much quicker than these tests.
Total Suspended SgljLds (TSS)
Solids in suspension in water, wastewater, or treated effluent.
Also known as suspended solids.
Tubing Blank
A sample taken by passing one gallon of distilled water through a
composite sampling device before initiation of actual wastewater
sampling.
Tuyeres
Openings in the shell and refractory lining of a furnace through
which air is forced.
Urea Fpjrma 1 d ehyde Resins
An important class of thermosetting resins identified as
aminoplastics. The parent raw materials (urea and formaldehyde)
are united under controlled temperature and pH to form
intermediates that are mixed with fillers (cellulose) to produce
molding powders for patterns.
Venturi Scrubber
A type of wet dust collector that uses the turbulence developed
in a narrowed section of a conduit to promote intermixing of
dust-laden gas with water sprayed into the conduit.
Volatile Substances
Materials that are readily vaporizable at relatively low
temperatures.
Washing Cooler
A large vessel where a flowing gas stream is subjected to sprays
of water or liquor to remove gas-borne dusts and to cool the gas
stream by evaporation.
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Wet Cap
A mechanical device placed on the top of a furnace stack that
forms a curtain from a water stream through which the stack gases
must pass.
Wetting Compounds
Materials which reduce the surface tension of solutions, thus
allowing uniform contact of solution with the wetted material.
Sodium alkylbenzene sulfonates comprise the principal type of
aurface^active compounds, but there are a number of other
compounds used.
Zero Discharger
Any industrial or municipal facility that does not discharge
wastewater.
563
-------
-------
APPENDIX A
TOXIC OHGANIC POLLUTANTS INCLUDED IN
TTO DEFINITION FOR PHOCESS
565
-------
APPENDIX A
Aluminum Subcategory
{1} Casting Quench
4. benzene
21. 2,4 r6-trichlorophenol
22. para-chloro meta-cresol
23. chloroform (trichloroniethane)
34, 2,4-dimethylphenol
39. fluoranthene
44. methylene chloride (dichloromethane)
65. phenol
66. bis(2-ethylhexyl)phthalate
67. butyl benzyl phthalate
84. pyrene
85. tetrachloroethylene
87. trichloroethylene
2) Die Casting
1. acenaphthene
4. benzene
7. chlorobenzene
11. ItIf1-trichloroethane
21. 2,4 r 6-tr ichlorophenol
22. para-chloro meta-cresol
23. chloroform (trichloromethane)
34. 2,4-dlmethylphenol
39. fluoranthene
44. methylene chloride (dichloromethane)
55. naphthalene
65. phenol
66. bis(2-ethylhexyl)phthalate
67. butyl benzyl phthalate
68. di-n-butyl phthalate
70. diethyl phthalate
72, benzo (a)anthracene (I,2-benzanthracene)
73. benzo (a)pyrene (3,4-benzopyrene)
76. chryaene
78. anthracene
80. fluorene
81. phenanthrene
84. pyrene
85. tetrachloroethylene
86. toluene
566
-------
(3) Dust Collection Scrubber
1, acenaphthene
21. 2,4,6-trichlorophenol
23. chloroform (trichlororaethane)
34. 2,4-dimethylphenol
39. fluoranthene
44, methylene chloride (dichloromethane)
65. phenol
66. bis (2-ethylhexyl) phthalate
68. di-n-butyl phthalate
70. diethyl phthalate
73. benzo {ajpyrene (3»4-benzopyrene)
84, pyrene
(4) Investment Casting
11. 1,1,1-trichloroethane
23. chloroform (trichloromethane)
44. methylene chloride (dichloromethane)
66. bis (2-ethylhexylJ phthalate
84. pyrene
85. tetrachloroethylene
87. trichloroethylene
(5) Melting Furnace Scrubber
1. acenaphthene
21. 2,4,6-trichlorophenol
23. chloroform (trichloromethane)
34. 2,4-dimethylphenol
39. fluoranthene
44. methylene chloride (dichloromethane)
65. phenol
66. bis (2-ethylhexyl) phthalate
68. di-n-butyl phthalate
70. diethyl phthalate
73. benzo (ajpyrene (3r4-benzopyrene)
84. pyrene
567
-------
(6) Mold Cooling
4. benzene
21. 2,4,6-triehlorophenol
22. para-chloro meta-cresol
23. chloroform (trichloromethane)
34, 2,4-dimethylphenol
39. fluoranthene
44. methylene chloride
65. phenol
66. bis(2-ethylhexyl) phthalate
67, butyl benzyl phthalate
84, pyrene
85. tetraehloroethylene
87. trichloroethylene
Copper Subcategory
(1) Casting Quench
23. chloroform (trichloromethane)
64, pentachlorophenol
66. bis{2-ethylhexyl)phthalate
71. dimethyl phthalate
(2) Dust Collection Scrubbers
1. acenaphthene
22. para-chloro meta-cresol
23. chloroform {trichloromethane}
34, 2,4-<3imethylphenol
55. naphthalene
58. 4-nitrophenol
64. pentachlorophenol
65. phenol
66. bis(2~ethylhexyl) phthalate
67. butyl benzyl phthalate
68. di-n-butyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
72. benzo(a}anthracene (1,2-benzanthracene)
74. 3,4-benzoflouranthene
75, benzo(k) flouranthene
76. chrysene
77, acenaphthylene
78. anthracene
81, phenanthrene
84. pyrene
56S
-------
(3) Investment Casting
1. acenaphthene
22, para-chloro meta-cresol
23. chloroform (trichloromethane)
34, 2,4-dimethylphenol
55. naphthalene
58. 4-nitrophenol
64. pentachlorophenol
65. phenol
66. bis {2-ethylhexyl)phthalate
67. butyl benzyl phthalate
68, di-n-butyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
72, benzo(a)anthracene (1,2-benzanthracene)
74. 3,4-benzoflouranthene
75. benzo(k) flouranthene
76. chrysene
77. acenaphthylene
78. anthracene
81. phenanthtene
84. pyrene
(4) Melting Furnace Scrubber
1. acenaphthene
22. para-chloro meta-cresol
23. chloroform (trichloromethane)
34. 2,4-dimethylphenol
55. naphthalene
58. 4-nitrophenol
64. pentachlorophenol
65. phenol
66. bis (2-ethylhexyl) phthalate
67. butyl benzyl phthalate
68. di-n-butyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
72. benzo(a)anthracene (1,2-benzanthracene)
74. 3,4-benzoflouranthene
75. benzo(k) flouranthene
76. chrysene
77. acenaphthylene
78. anthracene
81, phenanthrene
84, pyrene
569
-------
(5) Mold Cooling
23. chloroform (triehloromethane)
64. pentachlorophenol
66. bis(2-ethylhexyl)phthalate
71. dimethyl phthalate
Ferrous Subcategory
(!) Casting Quench
23. chloroform (trichloromethane)
34. 2,4-dimethylphenol
(2) Dust Collection Scrubber
1. acenaphthene
23. chloroform {trichloromethane)
31. 2,4-dichlorophenol
34. 2,4-dimethylphenol
39. fluoranthene
44. methylene chloride {dichloromethane)
55. naphthalene
54. pentachlorophenol
65. phenol
66. bis(2-ethylhexyl)phthalate
67. butyl benzyl phthalate
68. di~n-butyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
72. benzo (a)anthracene (1,2-benzanthracene)
76. chrysene
77. acenaphthylene
78. anthracene
80. fluorene
81. phenanthrene
84. pyrene
(3) Investment Casting
23. chloroform (trichloromethane)
44. methylene chloride {dichloromethane)
66. bis (2-ethylhexyl) phthalate
77. acenaphthylene
84. pyrene
570
-------
(4) Melting Furnace Scrubber
23. chloroform (triehloroniethane)
31. 2,4-dichlorophenol
34. 2,4-dimethylphenol
39. fluoranthene
44. methylene chloride (dichloromethane)
55. naphthalene
65. phenol
66. bis {2-ethylhexyl) phthalate
67. butyl benzyl phthalate
68, di-n-butyl phthalate
72. benzo (a)anthracene (1,2-benzanthracene)
76. chrysene
77. aeenaphthylene
78. anthracene
80. fluorene
81. phenanthrene
84. pyrene
(5) Mold Cooling
23. chloroform (trichloromethane)
34. 2,4-dimethylphenol
(6) Slag Quench
34. 2,4-dirnethylphenol
71. dimethyl phthalate
(7) Wet Sand Reclamation
1. acenaphthene
34. 2,4-dimethylphenol
39. fluoranthene
44. methylene chloride (dichloromethane}
55. naphthalene
65. phenol
66. bis (2-ethylhexyl) phthalate
68. di-n-butyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
72. benzo(a)anthracene {1,2-benzanthracene)
77. acenaphthylene
84. pyrene
571
-------
Zinc Subcategory
(1) Casting Quench
21. 2,4,6-trichlorophenol
22. para-chloro meta-cresol
31. 2,4~dichlorophenol
34. 2,4-dimethylphenol
39, fluoranthene
44. methylene chloride (dichloromethane)
65. phenol
66. bis(2-ethylhexyl} phthalate
68, di-n-butyl phthalate
70. diethyl phthalate
85, tetrachloroethylene
(2) Die Casting
1. acenaphthene
21. 2r4r6-trichlorophenol
22. para-chloro meta-cresol
24. 2-chlorophenol
34, 2r4-dimethylphenol
44. methylene chloride (dichloromethane}
55, naphthalene
65. phenol
66, bis (2-ethylhexyl) phthalate
68. di-n-butyl phthalate
70. diethyl phthalate
85. tetrachloroethylene
86. toluene
87, trichloroethylene
(3) Melting Furnace Scrubber
31. 2,4-dichlorophenol
34. 2,4-dimethylphenol
39, fluoranthene
44. methylene chloride (dichloromethane)
55. naphthalene
65. phenol
66. bis(2-ethylhexyl} phthalate
68. di-n-butyl phthalate
85, tetrachloroethylene
86. toluene
87. trichloroethylene
572
-------
(4) Mold Cooling
21. 2r4r6-trichlorophenol
22. para-chloro meta-cresol
31, 2i4-dichlorophenol
34. 2,4-diinethylphenol
39, fluoranthene
44. methylene chloride (dichloromethane)
65. phenol
66. bis(2-ethylhexyl) phthalate
68. di-n-butyl phthalate
70. dlethyl phthalate
85, tetrachloroethylene
573
-------
-------
APPENDIX B
WATER CHEMISTRY RECYCLE MODEL SENSITIVITY ANALYSES
575
-------
RECYCLE MODEL SENSITIVITY ANALYSES
A. GENERAL APPROACH
The recycle model described in the March 1984 Recycle Report {see
the record at 22.12) was used to evaluate impacts from varying
selected parameters to determine whether predicted recycle rates
are affected. The attached table summarizes the results from
over 400 separate computer trials. In generalf most trials were
run with varying make-up water qualities. A discussion of the
four make-up water qualities follows at the end of the table,
In most cases, any limiting factors which restricted the model's
ability to attain high recycle rates were correctable, usually by
pH control using hydrochloric acid or caustic soda additions.
This control is already built into all cost models utilizing
high-rate recycle. Some trials indicated limits based on calcium
sulfate or silica scale deposition, but generally such scaling
occurred at recycle rates which are higher than those being
considered for the individual process segments. Additional
computer trials indicated that special controls (i.e., recycle
loop side stream treatment) would have to be added to provide for
removal of part of the calcium sulfate or silica should it be
necessary to achieve recycle rates higher than those being
considered. Such controls have not been included in cost models.
The possible combinations of partial treatments are too numerous
to cover within the scope of this analysis.
The "Uncontrolled" columns in the attached table indicate the
recycle rates achieved for each make-up water quality if recycle
was attempted without any chemical addition to control pH
changes. For any rate less than 100 percent, the limiting factor
which first inhibits recycle is shown. The "Scale/Corrosion
Control" columns indicate that the model includes pH control to
enhance recycle by controlling either calcium carbonate scale or
corrosion. Again, if a recycle rate less than 100 percent is
listed, a second limiter is identified,
The percent recycle shown in the "Probable Recycle Rate" column
for co-treatment systems is the flow-weighted average recycle
rate for the individual segments which make up the system. For
example, if the model flow for aluminum casting quench is 551 GPD
and for mold cooling is 6,290 GPD, and their individual recycle
rates are 98 percent and 95 percent, respectively, the calculated
recycle rate for the co-treatment system is:
(0.98 x 551) + (0.95 x 6,290) = 95.2 percent
(551 + 6,290)
576
-------
B. RESULTS OF ANALYSIS
1. SENSITIVITY TO MAKE-UP WATER QUALITY
Over 300 trial runs were made measuring the effect of changes in
make-up water quality. Most of the trial runs compared four
different make-up water qualities to 29 model and 22 actual plant
recycle systems. It must be noted that available make-up water
quality data from all sources and across process segments have
been combined for analyses of individual process segment recycle
rates. However, for model analysis of recycle capability at
actual plants, the Agency used either actual plant make-up water
quality or average make-up water for the process segments
represented at the plant. Of these 51 systems, 31 involved one
process segment at a time, while the remaining 20 pertained to
central treatment systems.
As shown in the table, make-up water quality was a major
influence on the recycle rates only for the uncontrolled systems.
Chemical addition for pH control has been included in all models
to enable effective recycle. Note that the "Scale/Corrosion
Control" columns show relatively minor impact attributable to
make-up water quality. At times the pH range for effective
control may shift due to varying make-up quality, but it is
almost always one full pH unit in width. When the pH is
maintained within this band, scale and corrosion can be
controlled. As higher rates of recycle are attained through
added controls, the corresponding impact of make-up water quality
lessens since it becomes a smaller part of the total flow. The
most noticeable impact from make-up water quality is that for
some segments (e.g., Al-IC; Al-MFS; Cu-DDC; Cu-MCj Fe-UCj etc.),
the limiting factor in the uinconttolied mode changes from calcium
carbonate to corrosion or vice versa. This shift changes the
control chemical to be added from acid to alkali, at some
difference in cost. Cost models were developed using chemicals
applicable to average make-ups, so plants at either extreme (min
or max) may require different costs for substituted chemical
controls.
In summary, make-up water quality had some influence on
achievable recycle rates, but will not be a major deterrent to
attainment of recycle rates considered during development of
limitations and standards (referred to here as BPT recycle
rates). The addition of chemicals to control scaling and
corrosion and thus enhance recycle rates has been corrected for
any differences due to make-up quality.
2. SENSITIVITY TO SLUDGE MOISTURE CONTENT
Trials for two plants (1S6S4 and 17289) were run with dewatered
sludge solids contents varying between 5 to 20 percent for Plant
15654 and 5 to 50 percent for Plant 17289. The only measurable
impact was that the 5 percent solids samples did increase recycle
rates by 0.5 percent, probably because the higher moisture
content removed more materials which otherwise would inhibit
577
-------
recycle. All systems achieved the BPT recycle rates, even
without chemical additions. The primary significance of these
eight trials is to demonstrate that:
a. The solids content of well—dewatered sludges has no
measurable impact on ability to recycle.
b. For undewatered sludges at or below 5 percent solids,
any impact would be positive (i.e., tend to increase
recycle rates). This may explain, at least in part,
why some plants in the data base have achieved complete
recycle and others have not,
3. SENSITIVITY TO CENTRAL TREATMENT
Combined treatment systems for wastewaters from more than one
process were evaluated for their ability to attain recycle rates
based on those being considered for single process systems. As
in the case of single process systems, virtually all of the more
than 126 trials indicated that BPT recycle rates for single
processes are attainable by providing pH control through chemical
addition to the combined raw wastewaters. Of course, actual
installations may find it more cost effective to pretreat, limit
or otherwise separately control certain of their wastes prior to
mixing. But most commenters on central treatment questioned
whether end-of-pipe treated effluents could be recycled at high
rates. The model trials indicate that they can. With one
exception (Plant 18139), every nonferrous central treatment
system yielded a higher recycle rate than the BPT rate, using
only simple pH control to achieve that rate. Plant 18139 has
only 26 percent of the total flow originating from foundry
operations. A high sulfate concentration (342 mg/1) from non-
foundry operations proved difficult to handle, and caused
CaS04 deposition at 85 percent recycle. Of course, this
still could be high enough to comply with limits when the other
74 percent of non-foundry operations are considered. For ferrous
operations, combined treatment will not require control for
silica and/or calcium sulfate because recycle rates have been
adjusted to account, in part, for these problems, Therefore,
achievement of blowdown discharge flow rates would not require
side stream treatment for precipitation of silica and calcium
sulfate. Thus, the model trials have demonstrated the
practicability of high rate recycle, even for central treatment
systems.
4. SENSITIVITY TO RECYCLE LOOP TREATMENT EFFICIENCY
Three models were evaluated to determine whether differing levels
of treatment within the recycle loop affected the ability to
recycle. One set of runs dealt with a hypothetical ferrous
foundry with UC, MFSf and SQ segments. The treatment within the
loop (settling tank and surface oil skimming only) achieved 94 to
95.5 percent recycle before silica scaling became a problem. If
an additional treatment (consisting of clarifier with lime and
polymer addition, along with skimming) were installed within the
578
-------
recycle loop, as would be the case for central treatment plants
where wastewater is recycled after the treatment system at the
point of discharge, recycle rates increased to 96.5 to 97
percent, exceeding the probable 96 percent recycle rate. This
indicates another option available to plants with central
treatment. Rather than adding silica or calcium sulfate
sidestream treatments, additional process wastewater treatment
within the loop can achieve or surpass the BPT recycle rate.
Therefore, recycling back to the individual contributing
processes after central treatment facilities was shown to be
beneficial, but not necessary, to achieving the BPT recycle (and
blowdown) rates selected by EPA. Thus, companies could elect to
upgrade existing central treatment facilities which treat all
process wastewaters prior to recycle, rather than completely
replace them with smaller blowdown treatment systems. Moreover,
the water chemistry constraints contributed to central treatment
recycle systems by the slag quenching process, specifically
silica scaling, can be minimized by segregated recycle and
treatment of slag quenching process wastewaters.
Recycle model runs for an actual plant (06956) with those same
process segments confirmed that treatment by £ drag tank or
settling tank alone may not achieve a high enough recycle rate,
while more effective treatment within the loop will. In this
case, the drag tank only reaches 85 percent recycle, while a
clarifier (without chemical addition) reached 99 percent. The
actual plant treatment system is a lime and settle system. The
model indicated that this system could achieve recycle at 100
percent, while the BPT recycle rate (flow-weighted) is only 96.1
percent.
Finally, a nonferrous die caster (Plant 12040) was evaluated in
the same manner, and found to achieve 100 percent recycle using
pH control chemicals, even for simple inside-the-loop treatment.
The BPT recycle rate for die casters is 95 percent. This
evaluation of treatment efficiency sensitivity demonstrates that
recycle rates may be enhanced by improved primary (e.g.r lime and
settle) treatment within the recycle loop.
579
-------
RATE
- 4JSALYSIS
Uncontrolled
CJ
o
Process >feke-Up Rate
Segnait(3) (jhiallty % limiter
ALUMINUM:
OQ ffean 80
Min %
tex 0
DC Mean 60
Min 95
Max 0
OC Mean 97
Min 100
Max 10
1C Mean 70
Min 0
Max 0
MRS Mean 85
Min 92
Max 0
OQ& DC Mean 30
Min %
Max 0
UC & MC Mean 60
Min 85
Max 0
Scale/ Corrcts ion
CbntiDl __
AcH.
Kate
% Limiter
cc
oc
cc
oc
QC
OC
oc
oc
OQKR
OC
cc
GQRR
OC
CC
OC
OC
OC
CC
CC
100
100
98
100
100
100 .
100
100
85
85
85
100
100
99.5
100
100
99.5
99
100
97.5
SiO?/CaS04 Control
Limiter
Rate
%
GaS04
NR
MR
NK
NR
m
Si°2
OC
m
-- (1)
m
m.
Probable
Recycle
Rate (%)
98
98
98
95
95
95
98
98
98
85
85
85
96
96
96
96.2
96.2
96.2
97.6
97.6
97.6
-------
RECYCLE RATE SUmARY - PBOCESS MODEL ANALYSIS (Continued)
Scale/Garros ion
O3
HI
Process
COPPER:
DCC
UC
MC
MftGOTSIlM;
UC
GS
UC & GS
UTCOO trolled
•fake-Dp
Jjyality
Mean
Kin
Max
Mean
Min
Max
Mean
Min
Max
Mean
Min
Max
Mean
Min
Max
Mean
Min
Max
Ach.
late
%
97,5
0
0
100
0
0
93
0
0
0
0
0
95.5
100
0
99.5
0
0
Uiniter
CC
OOHR
CC
•ww, w
CORK
CC
CC
QQKR
CC
OGHR
ODER
CC
cc
__- .
cc
cc
COBR
CC
Control
Ach,
Bate
%
100
100
100
— — — p
100.
100
100
100
99.5
100
100
100
100
—
too
100
100
100
Liniter
—
—
— ._
— -»
— _
CaSQ^
— -
-«.»— ^
___
Sipg/CaSO& Control
SET
Mate
% Luniter
NK
NK
Probable
Becycle
Bate (X)
95
95
95
ye
98
98
95
95
95
98
98
98
100
100
100
99
99
99
-------
RECYCLE RATE SLM«RY - PROCESS MODEL ANALYSIS (Continued)
Process
Sggaent(s)_
ZINC:
DC
MES
GQ & DC
IJhcxiintrolled
Aeh.
Make-Up late
Quality % Limiter
Mean 30
Min 70
Max 0
Mean 60
Min 80
Max 0
Mean 93
Min 0
Max 0
Mean 20
Min 80
Max 0
METALS:
UC
vats
SQ
Mean 50
Min 0
Max 0
Mean 65
Min 92
Max 0
Mean 92
Min 0
Max 0
cc
CORK
CC
CC
CC
cc
cc
ODER
CC
Scale/Corrosion
Control
AcHI
Rate
% Limiter
CC
cc
cc
oc
cc
oc
cc
CORK
CC
oc
oc
oc
97.5
98
97
98
98
99
100
100
99.5
98
98
98.5
Sit*?
SiQj
Si02
Si02
Si02
S102
__.
__.
si°2
Si02
Si02
S102
SiU^/CaSO^ Control
Aeh.
Kate
% LiniiLer
—(1)
NR
(1)
NX
m
m
m
m
MR
97.5
97.5
97
95
95.5
93
93
94
92
SiOg
SKb
SI02
Si02
Si02
3102
SiQ?
Si02
S102
98 (10%)
98 (10%)
98 (10%)
98 (50/20%)
98 (60/10%)
98 (40/25%)
95.5 (30X)
95.5 (30%)
96.0 (30X)
Si02
NR
S102
Mt
MR
NR
NR
MR
NR
NR
Si02
Probable
Recycle
(,%)
98
98
98
95
95
95
96
%
96
97.6
97.6
97.6
97
97
97
96
%
96
94
94
94
-------
RECYCLE RATE SUMMARY - PROCESS MODEL ANALYSIS (Continued)
Process
Qualitj
FERROUS MEEftLS (Cant.):
WSR Mean
Min
Max
OQ & 1C
OQ & UC
CQ & SQ
UC &
UC
MFS & SQ
Mean
Min
Max
Mean
MLo
Max
Mean
Min
Mas
Mean
Min
Max
Mean
Min
Max
Mean
Min
H3K
Ibcon trolled
Ach.
Sate
%
97
0
0
93
0
0
30
70
0
60
85
0
60
85
0
60
80
0
94
0
0
Limiter
G01R
CC
OC
OORR
CC
CC
oc
CC
CC
oc
CC
CC
CC
CC
CC
CC
CC
SiOg
GOER
CC
Scale/ Corrosion
Control
"Ach.
Rate
%
NR
97
9/.5
100
100,
100
97
97.5
95.5
95
95.5
94.5
96
96.5
95.5
95.5
95.5
94
MR
94
92
Limiter
' HR
CaS(>4
CaS04
_«»
— _
Si02
Si°2
S102
SiOj
Si02
S102
Si02
S102
S102
m
Si02
Control
Rate
NR
NR
NR
limiter
NR
MR
NR
--- (1)
NR
NR
m.
97.5 (40/30%)
98.5 (4(R)
97.5 (20%)
S102
NR
m
NR
S102
CD
(1)
0)
(D
CD
(D
SiCfc
S102
S1O2
Si02
S102
S102
Probable
Recycle
Bate (%)
80
80
80
96.1
96.1
96.1
97.1
97.1
97.1
94.6
94.6
94.6
96.2
96.2
96.2
96.1
96.1
96.1
P5.8
95.8
95.8
-------
RECYCLE RATE StttfARY - PROCESS MODEL ANALYSIS (Continued)
Process
Segpent(s)
UC, MES & SQ
Simple Trt.
Inside loop:
ST; SS Chly
US, MES & SQ
Complete Ttt,
Inside Loop:
Cl; ELL; FLP;
SS
Make-Up
Quality
Mean
Min
Max
Mean
Min
Max
ihcontrollsd
Ach.
Bate
% Lunlter
70
0
0
40
0
85
cx;
CORK
cc
COiR
com
Scale/Corros ion
Concrol
Ach.
Bate
- I
95
95,5
94
Limlter
S102
S102
97
96.5
96,5
si°2
si°2
Ach.
Rate
—(2)
— (2)
--- (2)
m.
m.
NR
Limiter
Si02
NR
NR
HE
Probable
Recycle
Bate (%)
96.0
%.0
96.0
96.0
96.0
96.0
-------
USING DATA MM ACTUAL PLANTS (NOT MODEL PIAOTS)
Scale/Corros ion
uhcon trolled
Ach.
Procesa Make-Up Rate
Segment(s) Quality % Limiter
Plant 1:
Fe-MFS Actual 0 CC
Plant 2:
Fe-UC Actual 20 CC
Plant 3:
Fe-WSR A^^ual 40 CC.
Plant 4:
Fe-UC Actual 10 CC
Plant 5:
Fe-UC Actual 0 CC
Plant 6:
Fe-MFS Actual 50 CC
Plant 7:
M-DC Actual 0 CORK
Plant 04704 Actual 0 CORK
M-IC
Control
Ach.
Rate
% Limiter
91 Si02
96.5 310*2
96 Ca£Q4
96 Si02
97.5 Si02
95 Sil>2
100
1 S CaSf &/
/ jf vn:iii f*jfi
lJiO2/CaSOA Control
Ach.
Rate
% Limiter
(1) SiQ2
(1) Si02
m m
(1) Si02
NR NK
(1) Si02
— —
— (1) CaS04
Probable
Recycle
Rate (%)
96.0
97.0
80.0
97.0
97.0
96.0
95
85
-------
USING Dm FROM ACTUAL PLANTS (NOT MODEL PLANTS) (Continued)
Scale/Corroston
un
31
en
Uncontrolled
Process
_Segnen_t(s}_
Plant 06809
Qj-CQ & MC
Plant 06956
Fe-UC,
MES, SQ
Basic Trt.
SB only
Basic Trt.
Cl only
Actual-Cl,
FLL, FLP
tbmple te-
Add PF
Plant 07929
Fe-MES
Plant 10308
Al/Zn CQ & DC
Plant 10837
Fe-CC & UG
Make- Up
Quality
Actual
Actual
Segment
Mean
Min
Max
Segment
Segment
Segment
Segruent
Actual
Actual
Actual
Mean
Mlo
ftoc
Ach.
Rate
%
85
0
0
75
0
75
0
0
0
0
0
30
65
60
70
0
Linalter
OORR
OORR
OQRR
OORR
OORR
OC
OORR
CORR
COBR
QQKR
OORR
OURR
OC
oc
oc
oc
Control
Ach.
Rate
%
100
98
100
100
98
100
85'
99
100
100
100
100
100
99,5
99
100
Llratter
Si02
SiCh
— ,-
si°2
S102
—
„__
wvi™«»
— ««»
SiC^
Si02
—
Si0?/Casck Control
SET
Rate
% Liraiter
MR
NR
— (1)
MR
NR
Si02
NR
NR
NR
NR
Probable
Recycle
Kate (%)
95.2
96.1
96.1
96-1
96.1
96.1
96.1
96.1
96.1
96.1
96.2
96.9
96.9
96.9
96.9
-------
USING D&EA. FROM ACTUAL PLANTS (NOT MODEL PLANTS) (Continued)
Scale/Corrosion
Uncontrolled
Process
Segptent(s)
Plant 12040
Al/Zn-DC
Basic Trt.
SB csnly
Actual-EB,
Ch.Trt, ST
Advanced-
Add PF
Plant 1552QA
Fe-MFS
Plant 15520B
Fe-UC & SQ
Plant 15654
Fe-OQ
6 5% Sludge
Plant 17089
M/Zn - CQ
& DC
Make-Up
Quality
Actual
Segment
Segment
Segment
Segment
Actual
Mean
Min
Max
Actual
Actual
Segment
Segp&anL
Actual
Ach.
Rate
I
80
75
0
85
85
0
20
0
65
0
99.5
99
99.5
75
LLmiter
OC
CC
CORR
CC
CC
GOER
GOER
CORR
CORK
CORK
CORK
CORR
CORE
CORR
Control
Ach.
Rate
%
100
100
100
100
100
100
100
100
100
100
100
100
100
100
Limiter
™
---
—
—
— —4.
......
_ _*«
___
:::
— —™.
Rate
Control
Liraiter
Probable
Recycle
Rate (%)
95
95
95
95
95
96.0
96.0
96.0
96.0
96.1
98
98
98
96.2
-------
USING DfflA FROM ACTUAL ELWfiCS (NOT WfflEL PLftMS) (Continued)
CO
CD
Process
Plant 17289
Fe-UC
@ 51 Sludge
|15% Sludge
|251 Sludge
§35% SJuudge
§50% Sludge
Plant 18073
Fe-UC & MPS
Plant 18139
Al-GQ, DC
& ms
Plant 20147
Al-DC
Make-Up
Quality
Actual
Segnent
Segment
Segment
Segment.
Segpent
Segment
Actual
Mean
Mm
Max
Actual
Actual
Uncontrolled
Ach.
Rate
Scale/Corrosion
Control
98.
99
99.
99
99
99
99
97
95
95.
0
50
Limiter
ee
oc
oc
oc
cc
cc
cc
Si°2
Sl°2
OC
OC
OQRR
Ach.
Rate
100
100
10Q
100
100
100
NR
NR
NR
94
80
100
liaiter
m
NR
Ml
CaS04
NR
—(1)
—(1)
--(1,3)
NR
Si02
SI02
SiOo
Probable
Recycle
Rate(I)
97
97
97
97
97
97
97
96.2
96.2
96.2
96.2
96.1
95
(1) Si02/CaS04 controls were not evaluated for this test, but may be necessary to achieve probable
recycle rate. Refer to ferrous metals models for examples of the rate increases attainable through
such additional controls*
(2) In addition to rate increases described in footnote (1), note the benefits derived from more
advanced treatment within the loop (next set of runs below).
(3) 74 percent of the raw wstewater originates from non-foundry operations, seme of which contribute
heavily to the formaticn of CaSQ4, e.g., sulfuric acid pickle rinses.
-------
KEY TO PROCESS CODES:
KEY TO OTHER CODES:
CC: Cast Cleaning
CQ: Casting Quench
DC: Die Casting
DL: Die Lubes
UC: Dust Collection
GS: Grinding Scrubbers
1C: Investrasit Casting
MFS: Melting F\imace Scrubbers
MC: told Cooling
3Q; Slag Quenching
WSR: Wet Sand Reclamation
DOC: Direct Chill Casting
CC:
Ch.Trt:
Cl:
CORK:
EB;
FLL:
fLP:
MR:
PF:
SB:
Scaling Due to Calcium Sulfate Deposition
Scaling Due to Calcium Carbonate Deposition
Chemical Treatment to Break Bmilsions
CLarifier
Corrosion
Soulsion Breaking
frlocculation With Lirae
Flocculation With R>lymer
Efot Required. Proposed Reycle Rate is Achieved
Without Providing ehe Mditional Control Indicated
by TMs ColmEi.
Pressure Filtration
Settling Basin
Scaling Due to Silica Deposition
.Surface Skimming for Oil Removal
Settling "Rank
SS:
ST:
in parentheses indicate that portion of total flow %Aiich receives side stream treatment
for silica or calcium sulface removal. If two numbers appear, both controls are used at the
percentages indicated .
-------
MAKE-UP WATER CONCENTRATIONS
Parameter
Dissolved Solids
Hardness, CaC03
Alkalinity, CaC03
Silica, as Si02
Chloride
Calcium, as Ca
Sulfate, as 804
Suspended Solids
Concentration in mg/1
Segment
Varies
For
Each
Individual
Process
Segment
Mean
454
134
153
4.7
53
53
19
Kin
20
5
9
0.3
4
2
4
Max
3,225
424
436
14
615
170
102
8.0
7.2
8.8
Derivations:
Segment - Average of make-up concentrations reported for each
segment. Sometimes only one set of analyses was
available.
Mean - Overall average of ajJL make-up concentrations reported,
independent of segments.
Min - The lowest concentration reported for each parameter.
Max - The highest concentration reported for each parameter.
5SO
-------
APPENDIX C
GUIDANCE FOR IMPLEMENTING THE
METAL MOLDING AND CASTING CATEGORY REGULATIONS
591
-------
GUIDANCE FOR IMPLEMENTING THE
METAL MOLDING AND CASTING CATEGORY
REGULATIONS
Introduction
This appendix is intended to serve as an aid in implementing the
Metal Molding and Casting Industry Point Source Category Effluent
Limitations Guidelinest Pretreatment Standards and New Source
Performance Standards. The Metal Molding and Casting Regulations
(40 CFR Part 464) were published on October 30, 1985, in Federal
Register Volume 50, page 45212. This document presents the
development of permit limitations for several real and
hypothetical plants that illustrate by example how the metal
molding and casting effluent limitations guidelines and standards
are intended to be implemented.
Five permit examples are presented:
Example _!: BPT and BAT limitations for an integrated
copper casting and copper forming facility.
Example 2_i BAT limitations for an aluminum and zinc die
casting facility.
Example 3^; BAT/PSES limitations for a gray iron foundry
integrated with heavy equipment manufacture.
Example 4_: BAT for an investment casting plant with
intermittent discharge.
Example !>: PSES for a small malleable iron foundry.
The examples presented here cover a broad range of production
scenarios. Special emphasis has been placed on illustrating how
permits would be developed for plants with integrated water use
patterns. Therefore, the plants presented here do not
necessarily represent an average cross section of plants in the
category. This approach has been taken because by clarifying how
permit allowances would be set for unusual or complicated
situations, the development of permits for plants with straight-
forward operations is also better understood. In developing the
examples in this document, EPA has endeavored to include many of
the situations and examples raised by industry representatives
during public comment opportunities as requiring further
clarification.
As discussed in the preamble and technical development document,
the final metal molding and casting effluent limitations
guidelines and standards are mass-based and adhere to the
"building block" concept. Each regulated waste stream in an
outfall is assigned at discharge allowance based on some measure
of production. The sum of the allowances is the total allowance
for the outfall. The examples that follow assume some
592
-------
familiarity with the "building block" concept, as well as
familiarity with the material presented in the final metal
molding and casting preamble, regulations, and preceding sections
of this Development Document, Alternative mass limitations for
unregulated process wastewater streams and dilution streams at
direct discharging facilities are established by the NPDES permit
authority using best professional judgment (BPJ). Alternative
mass limitations for unregulated process wastewater streams and
dilution streams at indirect discharging facilities are
established by the Control Authority (see 40 CFR S403.12(a), and
40 CFR 8403.3) by using the combined waste stream formula (see 40
CFR 8403.6(e)(i), (ii)).
The following references are recommended to complement this
document:
1) "Guidance Manual for the Use of Production-Based
Pretreatment Standards and the Combined Wastestream
Formula," Environmental Protection Agency Permits
Division and Industrial Technology Division,
Washington, D.C., September 1985.
2) "Guidance Manual for Implementing Total Toxic Organics
(TTO) Pretreatment Standards," "Environmental
Protection Agency Permits Division, Washington, D.C.,
September, 1985.
3) "Guidance Manual for Electroplating and Metal Finishing
Pretreatment Standards," Environmental Protection
Agency, Effluent Guidelines Division and Permits
Division, Washington, D.C., February, 1984.
Calculation of_ Average Pr^oductj.on
Most of the mass limitations for waste streams regulated under
the metal molding and casting category are based on some mass of
production. Mass limitations for casting cleaning, casting
quench, direct chill casting, die casting, investment casting,
mold cooling, and slag quench wastewater are based on the mass of
metal poured. The limitations for wet sand reclamation are based
on the mass of sand reclaimed. The only limitations not based on
a mass of production are limitations for scrubber wastewater,
which are based on the volume of air scrubbed.
As the mass of production forms a critical foundation for the
calculation of the metal molding and casting limitations and
standards, it is essential that a permitted facility's actual
average production be determined accurately, based upon
information supplied by the permittee. As noted at 40 CFR
8122.45{b)(2){i), production for direct dischargers must be based
on "a reasonable measure of actual production of the facility,"
not on design maximum production capacity of the facility. An
equivalent measure of production must be used for indirect
dischargers.
593
-------
The ideal situation for the application of effluent limitations
guidelines is where production is constant from day to day and
month to month. Production for the purposes of calculating the
limitation would then be the average production rate. In
practice, production rates are not as constant as the ideal
situation. They vary because of market factors, maintenance,
product changes, down times, breakdowns, and facility
modifications. The production rate of a facility will vary with
time, and thus determination of production may be problematical.
To apply effluent limitation guidelines to a facility which has
varying production rates, the permit writer should determine a
single estimate of the long-term average production rate that is
expected to exist during the next term of the permit. This
single production value is then multiplied by both the daily
maximum and monthly average guideline limitations to obtain
permit limits.
The permit writer should avoid the use of a limited amount of
production data in estimating the production for a specific
facility. For example, the data from a particular month may be
unusually high and thus lead to the derivation of an effluent
limitation which is not actually reflective of the normal plant
operations and allow unwarranted levels of discharge.
The objective in determining a production estimate for a facility
is to develop a single estimate of the long-term average
production rate (in terms of mass of product per day) which can
reasonably be expected to prevail during the next term of the
permit. The following example illustrates the proper application
of guidelines*
Example: Company X has produced 331,500 tons, 301,500 tons,
and 361,500 tons per year for the previous three years. The
use of the long-term average production (331,500 tons per
year) would be an appropriate and reasonable measure of
production, if this figure was most representative of the
actual production expected to occur over the next term of
the permit and this number did not represent a temporary
increase in production. Also, in evaluating these gross
production figures, the number of production days must be
considered. If the number of production days per year is
not comparable, the numbers must be converted to production
per day before they may be compared. To convert from the
annual production rate to average daily rate, the annual
production rate is divided by the number of production daya
per year. To determine the number of production days, the
total number of normally scheduled non-production days are
subtracted from the total days in a year. If Company X
normally has 255 production days per year, the annual
production rate of 331,500 tons per year would yield an
average daily rate of 1,300 tons per day.
In the example above, long-term average production over the last
three years was used as the estimate of production. This
594
-------
estimate is appropriate when production is not expected to change
significantly during the permit term. However, if historical
trends, market forces, or company plans indicate that a different
level of production will prevail during the permit term, a
different basis for estimating production should be used.
Alternate Limits (Tiered Permits)
If production rates are expected to change significantly during
the life of the permit, the permit can i > alternate limits.
These alternate limits would become eff a when production
exceeds a threshold value, such as during luction variations
with the business cycle. Definitive cui* a is not available
with respect to the threshold value whj.ch should "trigger"
alternate limits. However, it is generally agreed that a 10 ;
20 percent fluctuation in production is within the range c
normal variability, while changes in production substantial^
higher than this range (such as 50 percent) could warrant
consideration of alternate limits. The major characteristics of
alternate limits are best described by illustration and example:
Example; Plant Y, has produced 400,000 tons, 375,000 tons,
2W7oSb tons, 240,000 tons, and 260,000 tons per year for
the past five years. Plant capacity is 500,'"^0 tons per
yeari the plant operates 250 days per year. this case?
production was reduced during a down-turn i the market
place and is now on the increase. How* r, annual
production levels may not return to the 400,I,J ton level
for several more years. In this situation a tiered permit
might be advisable. A permit might be written with two or
three tiers which apply to ranges of production. If average
production is expected to vary between 40 and 100 percent o£
capacity, alternate permit limits might be set as follows;
First Tier; Basis of limitation calculation = 50 percent of
capacity, or 1,000 tons/day.
Applicable production range = 40 percent
to 60 percent of capacity, or 800 to 1,200
tons/day.
Second Tier: Basis of limitation calculation = 70 percent of
capacity, or 1,400 tons/day.
Applicable production range = 61 percent to 80 percent of
capacity, or 1,200+ to 1,600 tons/day.
Third Tier: Basis of limitation calculation = 90 percent
capacity, or 1,800 tons/day.
Applicable production range - 81 percent
to 100 percent of capacity, or 1,600+ to
2,000 tons/day.
595
-------
In the above example, the first tier has an applicable production
range that covers plus or minus 20 percent of the basis of the
calculation for that tier. This can be seen by noting that the
basis of calculation for the first tier is 1,000 tons/day and the
threshold level that would trigger the next tier is set at 1,200
tons/day, or 20 percent higher. Similarly, the second and third
tiers have applicable production ranges of +14 percent and +11
percent, respectively. This is consistent with the general rule
that a 10 to 20 percent change in average production rate is
within the range of normal variability while a greater change
could warrant alternate limits.
Tiered permits generally require increased technical and
administrative supervision on the part of the NPDES permit
authority or the pretreatment Control Authority to verify
compliance with permit limits. Special reporting requirements
are usually necessary and should be detailed in the permit. The
permit should specify one set of alternate limits as the primary
limits. The primary limits would be based on the actual or
recent historical level of production. Compliance should be
evaluated based on the primary limits unless notification was
received in advance that the production rate had changed.
Compliance reports submitted by the permittee should contain
measurements or estimates of the actual production rate which
prevailed during the reporting period and the anticipated
production rate for the next reporting period. Tiered permits
should not apply for periods of less than one month.
Intermittent Discharge
Limitations and standards presented at proposal and in the two
notices of availability assumed that discharges from metal
molding and casting plants would always be on a continuous basis.
Information submitted in comments and confirmed by EPA indicate
that treatment is done or can be done on a batch basis with
discharge on an intermittent basis. For example, many smaller
plants with high rate recycle will have very small volumes of
blowdown wastewater to be treated. Also, this may include larger
plants which have very large treatment lagoons that can store
many days of treated wastewater. It is not uncommon in such
cases that controlled discharge is prescribed by the local permit
authority usually to coincide with periods of higher than average
flow in the receiving stream. Moreover, production schedules at
some plants may be sufficiently sporadic that discharges may not
occur for extended periods (e.g., three to four days in a week).
To allow these practices to continue,, the final regulations
contain provisions that would allow metal molding and casting
plants to discharge on an intermittent basis provided that they
comply with annual average limitations or standards that are
equivalent to the effluent limitations and standards applicable
to continuous discharging plants. Plants are eligible for the
annual average limitations and standards where wastewaters are
stored for periods in excess of 24 hours to be treated on a batch
basis. NPDES permits established for these "noncontinuous"
596
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discharging plants must contain concentration-based maximum day
and maximum for monthly average limitations or standards that are
equivalent to the mass-based limitations or standards established
for continuous discharging plants.
Municipal authorities may also elect to allow noncontinuous
discharge to POTWs. They may do so by establishing
concentration-based pretreatment standards equivalent to the
mass-based standards provided in §484.15, 484.16, 484.25, 484,26,
484.35, 484.36, 484.45 and 484.46 of the regulations. Equivalent
concentration standards may be established by multiplying the
mass standards included in the regulations by an appropriate
measurement of average production; raw material usage, or air
flow (kkg of metal poured, kkg of sand reclaimed, or standard
cubic meters of air scrubbed) and dividing by an appropriate
measure of average discharge flow to the POTW, taking into
account the proper conversion factors to ensure that the units
(mg/l) are correct. Permit example 4 covers an example of
intermittent discharge,
Applicability of the Metal Molding and Casting Effluent
Applicability of tne Metal MOI
Limitations Guidelines and Standards
Metal casting is a metal industry process that can either be a
stand alone process, or integrated with either metal
manufacturing, metal forming, or metal finishing operations.
Metal Molding and Casting Collocated Kith Metal Manufacturing
When aluminum, copper*, ferrous, or sine alloys art cast on-site
in conjunction with & metal manufacturing process, such as the
casting of ingots or pigs, waetewater generated during the metal
manufacturing and casting processes is regulated under the
following point source categories;
Aluminum - Nonferrous metals manufacturing, 40 CFR Part 421
Copper - Nonferrous metals manufacturing, 40 CFR Part 421
Ferrous - Iron and steel, 40 CPR Part 420
Zinc - Nonferrous metals manufacturing, 40 CFR Part 421
Copper continuous rod casting (propierzy casting} associated with
copper manufacturing is not regulated under nonferrous metals
manufacturing or metal molding and casting,
Metal Molding and Casting Collocated With Metal Forming
When aluminum, ferrous, or zinc alloys are cast on-site as part
of a metal forming process, such as the casting of billets or
strip for rolling or forming, wastewater generated during the
casting and forming processes is regulated under the following
point source categories:
597
-------
Aluminum - Aluminum forming, 40 CFR Part 467
Ferrous - Iron and steel, 40 CFR Part 420
Zinc - Nonferrqus metals forming, 40 CFR Part 471
When copper alloys* are cast on-site as part of a copper forming
process, wastewater generated during the casting process is
regulated under the metal molding and casting point source
category? wastewater generated during forming processes is still
regulated under the copper forming point source category.
Metal Holding and Casting Collocated With Metal Finishing
The metal molding and casting effluent limitations guidelines and
standards cover the following wastewaters generated by finishing
operations:
Aluminum casting cleaning wastewater
Aluminum grinding scrubber wastewater
Copper grinding scrubber wastewater
Ferrous casting cleaning wastewater
Ferrous grinding scrubber wastewater.
The grinding scrubber wastewater covered is generated by wet air
pollution control of grinding dusts generated by dry, rough
grinding of castings to remove excess metal (not part of
precision grinding or machining).
All other metal finishing operations (except metallic platemaking
and gravure cylinder preparation within printing and publishing
facilities, and existing indirect discharging job shops and
independent printed circuit board manufacturers covered under 40
CFR Part 413) are regulated either under the metal finishing
point source category, 40 CFR Part 433, or are unregulated waste
streams (see preamble for electroplating and metal finishing
point source categories, 48 FR 32462, July 15, 1983 for specific
definition of coverage).
*Except copper alloys that contain 0.1 percent or more beryllium
or 30 percent or more precious metal.
598
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Example 1^ - BPT and BAT for Coppery Casting and Forming Plant
This example is included to be illustrative of instances where
plants have sufficient treatment in place to achieve BPT
limitations, but must upgrade recycle and/or end-of-pipe
treatment in order to achieve BAT. In these or similar
instances, a short-term or interim BPT permit may be appropriate.
BAT limitations may be incorporated in the permit with a later
compliance date and a schedule for compliance set out in an
Administrative Order, or a new permit reissued at a later date.
Plant A is an integrated copper casting and copper forming
facility with direct discharge. Process wastewater from direct
chill casting and permanent mold casting operations are combined
with process wastewater from a copper forming hot mill in a
centralized recycle system. A continuous discharge from the
recycle system is treated before being released directly to a
river. A block diagram of the wastewater flows from Plant A is
provided in Figure C-I.
Average casting production is 164 tons of metal poured per shift,
three shifts per day. Of this total, 96 percent is cast by
direct chill methods, while the remaining 4 percent is cast in
permanent molds. Direct chill casting process wastewater,
defined in Section IV of the development document as contact
cooling water used during direct chill casting operations, is
generated. In addition, mold cooling process wastewater is
generated during permanent mold (bookmold) casting, where contact
cooling water is employed. The discharge allowance for the
operations that contribute to this combined outfall will consist
of building block allowances for the direct chill casting and
mold cooling wastewater developed from the metal molding and
casting regulation, 40 CFR Part 464; and a building block
allowance for the hot mill operations developed from the copper
forming regulation, 40 CFR Part 468.
The BPT mass discharge limitations for the metal molding and
casting operations would be calculated as follows:
Total average daily production: 164 tons/shift x 3
shifts/day = 492 tons/day
The BPT mass discharge limitations for the copper subcategory
appear at 40 CFR 8464.22(a)-(g) (50 FR 45254). Those limitations
are in terms of pounds of pollutant per million pounds of metal
poured. Converting the units of the above production values
results in 0.984 million Ibs/day for direct chill casting
production and for mold cooling production. The copper forming
operations at this facility are generated by contact cooling
waters from hot mill roll cooling and hot mill strip cooling.
These wastewaters are regulated as hot rolling spent lubricant.
The BPT mass limitations for this operation appear at 40 CFR
8468.ll(a). The BPT mass limitations are based on 990,000 off-
Ibs per day rolled in the hot mill. Note that chromium and
nickel are not regulated in metal molding and casting, but are
regulated in copper forming. For the purpose of this example it
599
-------
Direct Chill
Casting
Pe naanen C
Hold
Casting
o
o
Treatment
Discharge
To
Sutta.ce Waters
Hot
Rolling
BLOCK DIAGRAM OF EXAMPLE 1 -
Figure C-l
INTEGRATED COPPER CASTING AND FORMING PLANT
-------
will be assumed that the NPDES authority has requested and
obtained from Plant A analytical data for samples of wastewater
from the metal molding and casting processes, and that the data
indicate treatable concentrations of chromium and nickel are
present. Mass limitations are calculated using metal molding and
casting blowdown flows (Appendix J, preamble to final
regulations) and copper forming lime and settle treatment
effectiveness concentrations (see Table VII-20 of copper forming
Development Document). The maximum monthly average BPT mass
limitations for the metal molding and casting and copper forming
operations at Plant A are presented in Table C-l. Maximum
limitations for any one day would be calculated in a similar
manner.
BAT effluent limitations are calculated in the same manner and
are presented in Table C-2. Note that for BAT only chromium,
copper, lead, nickel, and zinc are regulated. TSS and oil and
grease will be regulated under BCT which will not be promulgated
until a later date for both the metal molding and casting and
copper forming categories.
Plant A is an actual plant that has BPT level treatment in place,
The plant currently discharges the following masses of pollutants
in treated wastewater originating from metal molding and casting
operations:
Copper: 0.17 Ibs/day
Zinc: 0.13 Ibs/day
OsG: 0.9 Ibs/day
TSS: 3.9 Ibs/day
As can be seen, these current discharge levels are well within
the BPT and BAT discharge limitations specified by the metal
molding and casting regulations. Plant A achieved these low
levels of pollutant discharges by high rate recycle and effective
use of lime and settle treatment technology.
To protect the identity of Plant A and the confidentiality of
production information for that facility, flow and production
information used to prepare the above example have been changed
from reported quantities.
Example 2_ - BAT for Aluminum and Zinc pie_ Casting Plant
Plant B is a direct discharging die casting facility with an
average production rate of 43 tons of metal poured per shift,
three shifts per day. Seventy-one percent of the metal poured by
weight is aluminum, the remaining 29 percent is zinc. Sources of
process wastewater at both the aluminum and zinc die casting
operations include a die lube spray, and noncontact mold cooling
water that leaks from the die casting equipment into the die
casting process area. Die cast parts are ejected from the die
casting machines into quench water tanks. In addition to the
above sources of process wastewater, the plant operates a dust
collection scrubber at 4,800 SCFM to collect dust and fumes
601
-------
Pol 1utant
Chromium
Copper
Lead
Nickel
Zinc
Table C-l
Plant A Maximum for Monthly Average BPT Effluent Limitations
Direct ChlTl Casting Hater + Mold Cooling yater * Hot Rolling Spent Lubricant « Total
unregulated -t-
,984xl06lbs x 0.506 Ibs +
day TO* Ibs
unregulated
bs x 0.018 Jbs
day 10* Ibs
x 0.214 Ibs + ,99xl06lbs x 0.103 j_bs
day 10* Ibs "djy 10* Ibs
.984xl06Ibs x 0.47 Ibs + Q,984xiQ6lbs x 0.199 Ibs + .99xl06lbs x 0.013 Ibs
¥ay T6* 1bs day TO* Ibs Tay ~TQ* 1
ynregylated + unregulated
bs
+ .9ixl061bs x 0.130 Ibs
"Hay ^TO6 Ibs
.984x106lbs x 0.518 Ibs + 0.984xl06lbs x 0.219 Ibs + .99xl06J_bs_ x 0.062 Jbs
day TO* Ibs day TO* Ibs day Td6 Ibs
S 0*6
TSS
[bs_ x 1.236 Ibs
day "TO6 Ibs
.984xl06l_b_s x 12.1 Ibs + 0.984xl061j>s x 5.09 Ibs + .
day TO* Ibs day TO* Ibs
.984xl06lbs x 18.1 Ibs + 0.984xl06lbs x 7.63 Ibs + .99xl06lbs x 2.008 Ibs
W Ibs
d"ay
day
Ibs
day
10 Ibs
0,323 Tb_s_*'
day
0.81 Ibs
Hay
0.671 Jbs
Hay
2.28 Ibs*
day
0.787 Ibs
day
18.1 Ibs
Hay
27.3 Jbs
day
*Suggested method of calculating Chromium and Nickel allowances for Direct Chill Casting and Hold Cooling Water
Chromium:
f984x!06lb_s x 145 gallons*1) + 0.§84xl06lbs x 61.3 gallons*1)
" ~
"day" TOWTis
x ,18 ing/l(2} x l^Jjb
454,000"¥g"
Hay TOW
.305 Ibs/day
xflOOO x 1000 Ibs] x 3.785 lite
L~™" 'IQ^Tbs J gall
iters
on
-------
Table C-l (Continued)
Nickel:
fo,984xl06lbs x 145 galjqnst1) + 0,984 106lbs x 61.3 gallons^! x EoQO x 10Q(
L (fay 1000"Tbs day TOW TVs J [_ TO*
x 1.27 mg/1^) x 1 Ib =2.15 Ibs/day
454,000 mg
000 x 10QO Ibs
IVs "
x 3.785 HJters
galTon
(1) See Appendix J of preamble to final regulations for the metal molding and casting category
{2} Lime and settle treatment effectiveness values for chromium and nickel (ten day) from Table
of Copper Forming Development Document
01
a
-------
o
Table C-Z
Plant A Maximum for Monthly Average BAT Effluent Limitations
PpJJjitjmt + Di.rect Chill Casting Miter + HoTd_ Coo]_i_ng Water «• Hot Rolling Spent Lubricant = Total
Chromium unregulated * unregulated + ,99xl06M>s x 0.018 Ibs = 0,272 Ibs*
day "To6 Ibs ~3Iy
Copper Q.984xlQ6TMJS x 0.506 Ibs * 0,984xl061bs x 0,214 Ibs + .QgxlO^lbs x 0,103 Ibs = 0.81 Jbs
day 10s Ibs day TB^ Ibs day "II6 Ibs day
Lead .984xlQ6lbs x .314 Ibs + 0.984xl06lbs x 0.132 Ibs * .99xl06]t>s x 0.013 Ibs = 0.452 Ibs
TO* Ibs "iiy HJ^ Ibs day TO6 Ibs "day
Nickel unregulated + unregulated + .99xl06lbs x 0.130 Ibs = 0,755 1 bs*
" day "lO6 Ibs day
Zinc .984xl06lbs x 0.36 Ibs + Q.984xl06lbs x 0,148 Ibs + ,99xl06lbs x 0.0i2 Ibs = 0.561 Ibs
TlFlbs day" ltF~lbs "3ay W Ibs "3iy
*Suggested method of calculating chromium and nickel effluent limitations for Direct Chill Casting and Ptold Cooling
water
Chromiym:
,984xlOfilbs x 145 gallons^) + 0.984xlG6lt»s x 61.3 gallons^! x FipOp_ x 1000 Jbsl x 3.785 liters
day IQQOTbs Wy 1000 Ibs I l^Ths J gallon
x 45 rag/1 (2>x lib - 0.254 Ibs /day
454,000 mg
Nickel :
[o.984xl06lbs x MS gallqnsCD + 0,984 lO^lbs x 61.3 iaHOTwClff x flOOO x 1000 Ibsl x 3s78b liters
[_ day 1000 Ibs day 1000 Ibs J [" 106 Ibs J gallon
x .37 irig/l(2)x 1 Ib = 0.62S Ibs/day
454,000 mg
(1} See Appendix J of preamble to final regulations for the metal molding and casting category
(2) Lime, settle and filter treatnient effectiveness ¥a]ue for chromium and nickel (ten day) from Table ¥11-20
of Copper Forming Development Docianent
-------
generated during aluminum dross quenching operations. A block
diagram of wastewater flows for Plant B is provided in Figure C-
2.
BAT effluent limitations for this facility would be based on
building block allowances for both the aluminum and zinc die
casting processes that generate wastewater. Aluminum die lube
spray is regulated as aluminum die casting wastewater (see 40 CFR
8464.13(c). The aluminum noncontact mold cooling water that
leaks into the process area is regulated as aluminum mold cooling
wastewater (see 40 CFR 8464,13{h). Process water in the aluminum
casting quench tank is regulated as aluminum casting quench
wastewater (see 40 CFR 0464.13(b). The zinc process wastewaters
are regulated similarly (see 40 CFR S464.43(a), (b), (d)).
Additionally, the scrubber wastewater that is generated by wet
scrubbing of aluminum dross quench dusts and fumes is regulated
as aluminum dust collection scrubber wastewater (see 40 CFR
1464,13{d), Dust collection wastewater covers a broad range of
wastewaters that issue from wet scrubbers operating on dust laden
air collected from the foundry, moldmaking, sand handling, and
other process areas associated with metal molding and casting
operations. Dust collection scrubber wastewater does not include
waetewater from scrubbers directly associated with furnace
operations or grinding operations.
The discharge mass limitations for the aluminum and zinc die
casting and casting quench operations are based on the mass of
metal poured that is associated with these operations. In this
example, the production rate is 43 tons poured per shift, three
shifts per day. Seventy-one percent of this production is
aluminum, the remainder is zinc. Distributing this production by
metal type and converting to pounds yields 0.183 million pounds
aluminum per day and 0.075 million pounds of zinc per day.
Multiplying these productions by the appropriate discharge
allowance per million pounds of production presented in the
regulations as cited above yield building block discharge
allowances for the respective waste streams,
The discharge limitations for the noncontact mold cooling water
leakage at a maximum could be calculated based on the above
productions {0.183mTllion Ibs/day aluminum and 0.075 million
Ibs/day sine) multiplied by the respective mold cooling pollutant
discharge allowance. However, while the Agency realizes that
minor leakage of noncontact mold cooling water may be
unavoidable, an allowance calculated in the above way is more
appropriate for contact cooling mold cooling water. If mold
cooling process water originates from leakage of noncontact
cooling water in the molding machine process area, an improvement
in regular maintenance and housekeeping procedures should abate
or eliminate the leakage.
Permit authorities are advised to work with plant personnel to
determine an estimate of leakage after a housekeeping program
designed to reduce or eliminate leakage is implemented. As a
benchmark, the BAT production normalized discharge flow for
60S
-------
Aluminum
Die
Casting
Aluminum
Dust
Collection
Aluminum
Casting
Quench
Zinc
Die
Casting
NonconLact
Cooling Water
Leakage
Zinc
Casting
Quench
Treatment
Discharge
To
Surface Waters
Figure C-2
BLOCK DIAGRAM OF EXAMPLE 2 - ALUMINUM AND ZINC DIE CASTING PLANT
-------
aluminum mold cooling is 92.5 gal/ton, the discharge flow for
zinc mold cooling is 94.5 gal/ton (a full list of BAT production
normalized discharge flows is presented in Table X-l of this
Development Document). For this example, assume that a thorough
review of the extent and nature of leakage of noncontact mold
cooling water into the die casting process area at Plant B
indicated that the water leakage rate could not be reduced below
30 gallons per ton at both the aluminum and zinc die casting
equipment through replacement of leaking sealsf valves, and
fittings and other normal maintenance efforts. Therefore, an
appropriate discharge allowance for the leaking noncontact mold
cooling water would be the ratio of the leakage rate over BAT
production normalized discharge flow, multiplied by the
production rate, and in turn multiplied by the appropriate
allowance specified in the regulation. An example calculation
follows later in this discussion. In no case should a mass
discharge allowance for noncontact mold cooling water leakage be
granted that is greater than the straight mold cooling process
water allowance calculated by multiplying the production by the
mold cooling regulatory allowance.
The discharge limitations for the aluminum dust collection
scrubber operation are based on the volume of air scrubbed. The
air flow rate through the scrubber of interest is 4,800 SCPM.
The scrubber operates three shifts or 24 hours per day. The
daily air flow through the scrubber is:
4,800 ft3/min x 60 min/hr x 24 hrs/day = 0,0069 billion
ft3/day
The discharge allowance for this operation is calculated by
multiplying the above average daily air flow by the appropriate
mass discharge allowance presented in the regulations to
determine the aluminum dust collection scrubber building block
allowance. Monthly average or maximum monthly average air flow
data for scrubbers are generally not available and are not
relevant because air flow is constant. Air flow through
scrubbers can be calculated from an air flow given in standard
cubic feet per minute, which is usually a design flow or other
constant operating air flow, multiplied by the minutes per day
the scrubber operates. Note that scrubbers do not necessarily
operate 24 hours per day. Exhaust blowers and scrubbers are
generally run only when dust and fumes are being generated, with
some appropriate time allowance for start-up and shutdown. It is
recommended that permitting authorities consult with plant
personnel to determine a daily time period of scrubber operation,
based on plant-specific production schedules and scrubber
configurations.
The following is an example calculation of the BAT maximum
monthly average lead limitations for Plant B. Limitations for
the other regulated pollutants would be calculated in a similar
manner. {See 40 CFR 8464.13{b), (c),
-------
Aluminum Casting Quench:
0.183 million Ibs/day x 0.0047 Ibs/million Ibs =
O.OOOSi Ibs/day
Aluminum Die Casting;
0.183 million Ibs/day x 0.0034 Ibs/million Ibs =
0.00062 Ibs/day
Aluminum Dust Collection Scrubber!
0.0069 billion SCF/day x 0.117 Ibs/billion SCF =
0.00081 Ibs/day
Aluminum Mold Cooling:
0.183 million Ibs/day x 0.151 Ibs/million Ibs x
30 gal/ton/92.5 gal/ton = 0.00896 Ibs/day
{Ratio of actual leakage flow over BAT production normalised
flow. This special step applies to noncontact mold cooling
water leakage only.)
Zinc Casting Quenchs
0.075 million Ibs/day x 0.0116 Ibs/million Ibs =
0.00087 Ibs/day
Zinc Die Casting:
0.075 million Ibs/day K 0.0022 Ibs/million Ibs =
0.00017 Ibs/day
Zinc Mold Cooling:
0.075 million Ibs/day x 0.103 Ibs/million Ibs x
30 gal/ton/94.5 gal/ton = 0.00245 Ibs/day
Total BAT maximum monthly discharge allowance for lead:
0.0147 Ibs/day.
Example 3_ - BAT/PSES Limitations for Integrated Gray Iron Foundry
and Heavy Equipment Manufacturer
Plant C is a large integrated equipment manufacturer that pours
2,500 tons/day gray iron and 200 tons/day steel. The plant
operates two shifts per dayf five days per week. The gray iron
is melted in a cupola? cupola exhaust gases pass through a
quencher and a venturi scrubber to remove fumes and particulate.
Following the venturi scrubber, the exhaust gas passes through a
separator where water introduced in the quencher and the venturi
scrubber is removed and recovered. After wet scrubbing and
scrubber water recovery, the exhaust gas passes through an
aftercooler, where the cleaned gas comes into contact with water
608
-------
to reduce the exhaust gas temperature and volume and to condense
moisture. A block diagram of the wastewater flows from Plant C
is presented in Figure C-3.
Slag from the cupola is quenched with water. The molten gray
iron is poured in sand molds of various sizes, many with
intricate cores that form the inside surfaces of the castings.
After the castings cool, the castings are released from the molds
during sand shake-out. Dust from automatic mold-making machines,
sand shake-outf core making, sand mulling, and other sand
handling operations is collected along with transfer ladle and
pouring floor fumes in six de-centralized air collection systems.
Exhaust air from each of the air collection systems is cleaned by
wet scrubbing. Exhaust blowers operate 16 hours per day? the air
flow through each scrubber is 40,000 SCFM.
Steel is melted in an electric arc furnace and poured at a rate
of 200 tons per day. The steel is cast in permanent molds that
are cooled with noncontact cooling water. The steel castings are
ejected into quench tanks where further cooling takes place.
Noncontact cooling water is used as makeup water for the quench
tanks and for other process water make-up needs.
All of the steel castings and one quarter of the gray iron
castings proceed to a grinding and machining area where flash,
sprues, and runners are cut from the castings, and remaining
excess metal is ground off. Air laden with dust generated during
these rough finishing operations is collected and cleaned in a
wet scrubbing operation. The rough finished workpieces are
further machined and milled to final product specifications
before being transferred to painting and assembly areas. An oil
and water emulsion is used as a contact coolant and lubricant in
these final precision tooling operations. Grinding dust and
machining waste (metal particles in oily solution) that falls to
the floor is washed with water to a grinding room sump.
The total wastewater flow from these operations flows to a
central wastewater treatment facility with a single discharge.
The flow to treatment consists of:
1. Continuous blowdown discharge from the cupola quencher and
venturi scrubber water recycle system.
2. Continuous blowdown discharge from the cupola aftercooler
recycle system.
3. Batch discharge from dust collection scrubber recycle system
drag tanks.
4, Continuous discharge of slag quench water.
5. Batch dumps of casting quench tanks.
6. Excess noncontact mold cooling water not used as makeup to
the quench tanks and other processes.
609
-------
6,800 GPD
75.000 CPD
228,500 CPD
ZOO CPD
Discharge
To
Surface Waters
Or To POTW
*Quencher, Venturi Scrubber, Dust Collection, Slag Quench, Casting Quench, CrlnJtng Scrubber
1.000 GTO
Figure C-3
COMBINED WASTESTREAMS FOR EXAMPLE 3 - INTEGRATED GRAY IRON FOUNDRY AKD
HEAVY EQUIPMENT MANUFACTURER
-------
7. Continuous discharge of grinding scrubber wastewater.
8. Grinding room floor wash water,
9. Foundry product testing laboratory wastewater.
A BAT permit for this outfall or PSES for an equivalent discharge
to a PQTW sewer would consist of the following allowances:
1. A separate melting furnace scrubber mass allowance (see 40
CP1 8464.33(f )(D, and 0464.35(f) (1)) for the cupola exhaust
gas quencher and for the venturi scrubber. This plant has a
multiple scrubber configuration that does occur in the
ferrous subeategory. One mass allowance should be given for
the quencher and a second mass allowance should be given for
the venturi, as each is a discrete wet scrubbing device.
(See 40 CFR 8464.31{h)(i).) The mass allowance for each
should be based upon the daily air flow through the
scrubber. Daily air flow is calculated from the typical
scrubber air flow in SCPM (a constant rate, usually equal to
or close to the design rate) multiplied by *.ie minutes per
day the scrubber operates. If a cupola is not operated
continuously* but goes through a daily start-up and shut
down cycle* cupola scrubbers generally operate from the time
the cupola fuel bed is lighted until the cupola bottom has
been dropped and cooled.
2, Aftercoolers are in service at a limited number of ferrous
foundries with cupola melting. They are used to lower
exhaust fan power requirements by lowering the temperature
and reducing the moisture content of exhaust gasesr and
thereby reducing the volume of gas going to the exhaust fan.
The water systems of aftercoolers and scrubber systems are
kept segregated; aftercooler water should be much cleaner
than scrubber water. A typical aftercooler configuration is
a packed tower where exhaust gas and aftercooler water pass
countercurrently. The aftercooler water is collected, run
through a cooling tower, and recycled. As aftercooler water
only comes into contact with previously cleaned exhaust gas,
it should contain a relatively minor pollutant load, if any.
If no't, poor scrubber performance and possibly excessive air
emissions may be occuring. EPA recommends that aftercooler
water be sampled and analyzed by the discharger. As the
characteristics of aftercooler water are expected to be
somewhere between the characteristics of noncontact cooling
water and melting furnace scrubber water, a high degree of
recycle of aftercooler water should be expected (note that
if aftercooler water is not recycled it is more likely to be
a dilute waste stream). Viable uses of aftercooler water
discharge are as make-up water to slag quench, melting
furnace scrubber, or dust collection scrubber system, with
sampling data it can be determined whether it should be
considered to be dilution water or unregulated process water
for the purpose of calculating pretreatment standards for
611
-------
indirect dischargers (the definition of a dilute waste
stream is provided by the May 17 f 1984 Federal Register, 49
FR 21024). While aftercooler water is unregulated according
to the definition in the General Pretreatinent Regulations,
Control Authorities have the authority to determine whether
unregulated streams should be considered dilution under 40
CFR 8403.6(d). The combined wastestream formula would be
used to establish the PSES mass allowances. EPA recommends
best professional judgment to base a BAT permit allowance on
the metal molding and casting treated effluent
concentrations presented tn Appendix L of the metal molding
and casting preamble multiplied by the average blowdown
effluent flow from the aftercooler recycle system. In no
case should the mass allowance of aftercooler water exceeU
the mass allowance for a single stage melting furnace
scrubber. Moreover, the resulting PSES mass allowances
calculated by the combined wastestream formula and BAT mass
allowances using the above method should be nearly
identical. If there is no discharge there would be no
allowance,
3. A dust collection scrubber mass allowance (see 40 CFR
8464.33{cHl), i464,35(e)(l)) should be given for each of
the six scrubbers operating on the de-centralized air
collection systems.
4. A slag quench mass allowance (see 40 CFR 8464.33(h)(1),
i464.35(h)(1)) should be given for slag quench wastewater.
5. A casting quench mass allowance (see 40 CFR 8464.33|b)(1),
8464.3S(b)(1)) should be given for casting quench
wastewater.
6. Noncontact mold cooling water should be treated as a
dilution waste stream for PSES (use combined waste stream
formula) and no allowance for BAT should be necessary unless
there are unusual, site-specific intake (make-up) water
quality circumstances.
7. Grinding scrubber wastewater is a regulated waste stream
that is given no discharge allowance (see 40 CFR 8464.33(d)
and S464.35(d)).
8. Grinding room floor wash water is an unregulated process
water stream. The floor area being washed is shared by both
dry rough grinding operations with air scrubbers that are
covered under metal molding and casting, 40 CFR Part 464,
and precision machining, generally covered under metal
finishing, (see 40 CFR 8433.10), depending on the other
finishing operations at the facility. Before giving any mass
allowance for floor wash, the permit writer should ensure
that good housekeeping techniques such as dry moppingf high
pressure/low volume sprays and the elimination of drips,
leaks, and spills, have been implemented to the extent
possible. To calculate a BAT mass discharge allowance for
612
-------
these operations? the average floor wash water usage
(volume/day) should be determined, and then prorated to the
metal molding and casting (rough grinding) and precision
machining operations. One method of proration would be to
distribute the flow based on the relative area of floor
space occupied by each operation. A BAT mass allowance for
the flow attributed to metal molding and casting operations
should be calculated by multiplying the flow by the metal
molding and casting treated effluent concentrations
presented in Appendix L of the metal molding and casting
preamble, converting units as appropriate. The mass
allowance for the flow attributed to the precision machining
operations could be calculated based on the metal finishing
flow times the metal finishing BAT concentration limitations
{see 40 CFR 8433,14). In developing PSES mass discharge
allowances, the combined wastestream formula is used. If
one assumes that the precision machining operations are
unregulated (i.e., none of the six operations listed in
8433.10 is present at this facility), then only the
wastewater flow rate of the unregulated wastestream is
needed to use the formula. However, if one assumes that it
is regulated metal finishing wastewater, then the standards
for metal finishing would be used in the formula to develop
a mass allowance.
9. Foundry product testing laboratory wastewater is an
unregulated process wastewater flow. This wastewater should
be relatively dilute. However, it should be sampled and
analyzed. For the purpose of this example, it will be
assumed to contain treatable concentrations of toxic metals,
TSS, and other pollutants. A BAT mass discharge allowance
should be calculated based on the average daily flow from
the laboratory multiplied by the metal molding and casting
treatment effectiveness concentrations presented in Appendix
L of the metal molding and casting preamble. In developing
PSES mass discharge allowances, the combined wastestream
formula may be used with resulting mass limitations that
should be nearly identical.
The following are example calculations of the BAT and PSES
maximum for any one day discharge limitation of lead for Plant C,
Plant C Pact Sheet:
2,500 tons gray iron poured per day
200 tons steel poured per day
Total Production - 2700 tons/day
Note: This large plant casts primarily gray iron, and
therefore the entire production at the plant is subject
to BAT and PSES limitations based on filtration.
613
-------
Cupola Scrubber:
Air flow: 60,000 SCPM
Period of operation: 18 hours/day (including cupola
startup and shutdown)
Wastewater discharge: 50,000 gallons/day
Dust Collection Scrubber:
Air flow: 40,000 SCPM/scrubber x 6 scrubbers
Period of operation: 16 hours/day
Wastewater discharge: 20,000 gallons/day
Grinding Room Data:
500 gallons per day grinding scrubber wastewater
discharge
200 gallons per day floor wash water
40 percent floor space dedicated to dry, rough grinding
60 percent floor space dedicated to finish machining
Foundry Product Testing Laboratory:
1000 gallons wastewater/day
Slag Quench:
50,000 gallons wastewater/day
Casting Quench:
25,000 gallons wastewater/day
Aftercooler:
Wastewater sampling and analysis indicates it should be
considered unregulated process wastewater! 6,800
gallons/day is discharged.
Noncontact Cooling Water:
75,000 gallons/day discharged to central treatment
facility
Calculation of BAT maximum for any one day lead limitations (see
40 CPR S464.33(a)-(i) [50 PR 45261]):
Metal molding and casting, ferrous subcategory, BAT one-day
maximum treatment effectiveness concentration: 0.53 mg/1 lead
Metal finishing BAT one-day maximum limitations: 0.69 mg/1 lead
614
-------
Melting furnace scrubber (regulated);
Gas quencher!
60,000 SCFM x 18 hours x 60 minutes x 1.86 Ib lead
day hour billion SCF
= 0.121 Ib lead
day
Venturi scrubber:
60,000 SCFM x 18 hours x 60 minutes x 1.86 Ib lead
lay hour billion SCF
= 0.121 Ib lead
day
Cupola exhaust gas aftercooler (unregulated):
6,800 gallons x 3.785 liters x 0,53 mg x 1 Ib
day gallon liter 454,000 mg
= 0,030 Ib lead
day
Dust collection scrubber wastewater (regulated);
6 x 40,000 SCFM x 16 houra x 60 minutes x 0.398Ib lead
day hour billion"SCF
= 0.092 Ib lead
day
Slag quench wastewater (regulated):
2700 tons x 2,000 Ibjj x 0.0964 Ib lead - 0.521 Ib lead
day ton mil lion ~lbiday
Casting quench wastewater (regulated}i
2700 tons x 2,000 Ibs x 0.0252 Ib lead = 0.136 Ib lead
day ton mil lion Ib~a day
Grinding Scrubber Wastewater (regulated):
No discharge allowance.
615
-------
Grinding Room Floor Wash Water (unregulated)?
Metal Molding and Casting Operations:
200 gallgM x 0.40 x 3.785 liters x 0.53 ru
day gallon liter
* 1 lb * 0.00035 lb lead
454,000 mg day
Precision Machining Operation:
200 gallons x 0,60 x 3.785 H.terj3 x 0.69 mq
day gallon liter
x 1 lb = 0.00069 lb_ lead
454,000 mg day
Foundry Product Testing Laboratory Wastewater (unregulated)
1000 gallons x 3.785 liters x 0.53 mg x 1 lb
day gallon liter 454,000 mg
= 0.0044 lb lead
day
Total BAT maximum for any one day discharge limitation for
lead:
1.026 lb lead
day
Calculation of PSES maximum for any one day discharge standard
for lead;
The following streams are considered regulated wastestreams
because effluent limitations and standards {PSES) have been
promulgated for them in the metal molding and casting point
source category: cupola quencher and venturi scrubber wastewaterf
dust collection scrubber wastewater, slag quench water, casting
quench tank dumps, and grinding scrubber wastewater. It will be
assumed for the purposes of these calculations that aftercooler
recycle system biowdown has been sampled and anlayzed and was
determined to contain treatable levels of toxic pollutants,
including lead. Noncontact mold cooling water should be treated
as a dilution waste stream. Finally, grinding room floor wash
water and foundry product testing laboratory wastewater are
unregulated process waste streams.
Mass discharge allowances should be calculated using the combined
wastestream formula (CWF):
616
-------
N
Ml x
FT -_Fp , where
, Fi
L-l
M«p = Alternative mass limit for the pollutant in the
combined wastestream (mass per day)
Mi = Production-based categorical pretreatment standard for
the pollutant in regulated stream i (or the standard
multiplied by the appropriate measure of production if
the standards being combined contain different units of
measurement)
Fi = Average daily flow (at least 30 day average) of
regulated stream i
FD = Average daily flow (at least 30 day average) of dilute
wastestream(s) entering combined treatment system
FT = Average daily flow (at least 30 day average) through
the combined treatment facility (including regulated,
unregulated and dilute wastestreams)
N = Total number of regulated streams
Alternative mass limits are developed by adding together the
calculated mass values from a production-based categorical
standard for a pollutant (Mi) in each regulated process
wastestream that is combined. If the production bases for the
production-based standards being combined are different, as is
true in this case, then each of the production-based standards
would have to be multiplied by the appropriate daily production
basis for each regulated process, before the standards were added
together.
The first step in implementing the combined wastestream formula
is to calculate 51 Mi, the sum of the mass limits of the
regulated waste streams. Mass limits for the regulated waste
streams are calculated in the same manner as for BAT:
Melting furnace scrubber (regulated):
Gas quencher:
60,000 SCFM x 18 hours x 60 minutes x 1,86 Ib lead
day hr billion SCF
= 0.121 Ib lead
day
617
-------
Venturi scrubber:
60,000 SCFM x 18 hours x 60 minutes x 1 *j_6 lb.t lead
day hr billion'SCF
= 0.121 lb__ lead
day
Dust collection scrubber (regulated):
6 x 40,000 SCFM x 16 hours x 60 minutes x 0.398 lb lead
day hour billion SCF
= 0.092 lb lead
day
Slag quench (regulated):
2700 tons x 2000 Ibs x 0.0964 lb lead = 0.521 lb lead
day ton million Ibsday
Casting quench (regulated):
2700 tons x 2000 Ibs x 0.0252 lb lead * 0.136 lb lead
day ton million Ibs day
Grinding scrubber (regulated);
No discharge allowance
Thus the sum of the mass limits for the regulated wastestreams,
is 0.121 Ib/day + 0.121 Ib/day + 0.092 Ib/day + 0.521 Ib/day +
0.136 Ib/day + 0.0 Ib/day = 0.991 Ib/day.
The average daily flow through the combined treatment facility,
FUJI, is the sum of the discharge flows of the regulated,
unregulated, and dilute streams (see Plant C Fact Sheet):
Haste Stream Flow Type
Cupola quencher & venturi 50,000 GPD regulated
Cupola aftercooler 6,800 GPD unregulated
Dust collection scrubber 20,000 GPD regulated
Slag quench 50,000 GPD regulated
Casting quench 25,000 GPD regulated
Noncontact cooling water 75,000 GPD dilution
Grinding scrubber 500 GPD regulated
Grinding room floor wash 200 GPD unregulated
Product testing 1,000 GPD unregulated
Total flow (FT) 228,500 GPD
These flows and mass limits values are illustrated in Figure C-3.
618
-------
The average daily flow of dilute wastestreams, FD, is equal
to the flow of noncontact cooling water, 75,000 gallons/day. The
average daily flow of the regulated wastestreams, F^ j_s
145,500 gallons/day.
Substituting these values into the combined wastestream formula
yields:
MT * 0.991 Ib xf228,500 GPP-75,OOP GPP
day
145,500 GPD
= 1.045 Ib
clay
Thus the maximum for any one day limitation for
combined wastestream is 1.045 Ibe pec day.
lead in the
Note that for PSES TTO is also controlled for the melting furnace
scrubber, dust collection scrubber, casting quench, and slag
quench metal molding and casting operations. See Example 5 for
the method used to calculate TTO mass limitations.
Example ^ - BAT for Investment Casting Plant
Discharge
Witji Intermittent
Plant D is a small investment casting foundry with direct
discharge that pours 3 tons of steel per day, 0.5 tons of gray
iron per day, 2 tons of brass per day, and 1 ton of aluminum per
day. Wastewater is generated by the following investment casting
operations! mold backup, hydroblasting of castings, and dust
collection scrubber. Plant D operates one shift per day, three
days per week, 50 weeks per year, 150 production days per year.
All wastewater generated is collected in a holding tank, treated
on a batch basis at the end of the production day, and discharged
at the end of the production week. A wastewater flow block
diagram for Plant D is provided in Figure C-4.
BAT discharge limitations would be developed for this facility
with additive (building block) discharge allowances given for the
ferrous investment casting operations (steel and gray iron), the
bronze (copper) investment casting operations, and the aluminum
investment casting operations. The ferrous investment casting
allowance would be based on the effluent limitations for plants
that cast primarily steel because steel is the major ferrous
alloy cast at Plant D. Investment casting wastewater is defined
as wastewater generated during investment mold backup, hydroblast
cleaning of investment castings, and the collection of dust
resulting from the hydroblasting of castings and the handling of
the investment material. Note that the investment casting
process definition includes dust collection and therefore
separate allowances for dust collection scrubbers are not
warranted. An example development of the BAT discharge maximum
for any one day limitation for zinc for Plant D follows.
619
-------
to
o
Ff rroiig
Investment
Casting
i
Copper
Investment.
Casting
' i
1
Aluminum
Investment
Casting
i '
Treatment
Tank
Intermittent
Discharge Tit
Suriace Watera
Figure C-4
BLOCK DIAGRAM OF EXAMPLE 4 - INVESTMENT CASTING PLANT
-------
Plant D Pact Sheet:
Ferrous Investment Castings
3.5 tons/day
525 tons/year
7r200 gallons recycle system blowdown wastewater/day
Copper Investment Casting:
2 tons/day
300 tons/year
5,800 gallons recycle system blowdown wastewater/day
Aluminum Investment Casting:
1 ton/day
150 tons/year
2,600 gallons recycle system blowdown waatewater/day
Plant D operates a central recycle system with drag tank, and a
central blowdown treatment system. Plant D also is a
noncontinuous discharger (once per week). This plant discharges
46,800 gallons of batch (lime and settle) treated wastewater from
a small one-quarter acre storage pond once per week. Therefore,
Annual average mass limitations and Bgjcimum day and maximum for
monthly aye_rage_ eg nee n t r at ion iTm i t at ton's' "ar e applicable. These
BAT limitations are 'found in t he r e gula t ions as follows; ferrous
(primarily steel} investment casting at 40 CFR 8464.33(e)(2)
[second table]; brass (copper) investment casting at 40 CFR
S464.23(e) [second table]? and aluminum investment casting at 40
CFR 8464.13^f) [second table].
Zinc maximum concentrat ion for any one dayi
Ferrous Investment Casting (production of steel plus gray
iron);
1 ton
2(1,000 Ibs)
X = 7,200 gallons x 1 day x
day 3,5 tons
= 1,029 gallons
1,000 Ibs
1.47 mq x 1,320 = 1.89 mq
"T 1,029 "T
The above ratio of water use (1,320/X) is obtained from the
footnote to the table of limitations, and X in the ratio is the
actual normalized bjlgwdown flow for ferrous gubcategory
production at this plant.
621
-------
Copper Investment Casting :
X = 5,800 gallons x 3. day x I ton
day 2 tons 2 (1*000 Ibs)
= 1,450 gallons
1,000 Ibs
0.76 mg x 1,320 = 0.69 mg
1 17450 1
Aluminum Investment Casting:
X = 2,600 gallons x 1 day x ____J
day 1 ton 2 (1,000 Ibs)
= If300 gallons
1,000 Ibs
1.14 mg x 1,320 = 1.16 mg
1 TTJOO 1
The maximum zinc concentration for any one day for the total
discharge flow would be calculated as a flow weighted average of
the above concentrations:
(7,300 fal/dav i 1. 8 j_ Mlfil *
-------
It is recommended that noncontinuous discharging plants with
annual average mass limitations track their mass discharged
throughout the year by a cumulative total ("running balance") of
the mass of each pollutant discharged. By closely monitoring the
mass discharged during each batch and updating the total
discharge to date, plants with potential compliance problems will
be aware of the situation with adequate time to take remedial
action. Remedial action might include wastewater flow reduction
and improvement to treatment system performance.
Example ^ - PSES fo_r_ Small. Malleable Iron Plant
Plant E is a small malleable iron foundry with discharge to a
POTW sewer. The foundry pours eight tons of metal per day, 260
days per year. Total average yearly production is 2r080 tons.
Process wastewater is generated by casting cleaning, casting
quench, and dust collection and grinding scrubber operations.
The plant has a combined recycle system with a drag tank after
which process wastewater is recycled to the wet scrubber, casting
cleaning, and casting quench processes. Slowdown flow is treated
in a central treatment facility. Treated process wastewater is
combined with sanitary wastewater before being discharged to the
city sewer. The foundry has various product lines; not all cast
products go through the same processing steps. Five tons of
metal are poured per day that result in castings that are
cleaned. Two tons of metal are poured per day that result in
castings that are quenched. A single wet dust collection
scrubber cleans air that is laden with dust from sand handling
(mold and core making/ shake-out, sand mulling), pouring floor
fumes, and grinding operations. The scrubber air flow is 12,000
SCPMj 90 percent of the air scrubbed originates from the sand
handling and pouring floor areas, the remaining 10 percent
originates from the grinding area. A dry melting furnace
scrubber (baghouse) is used at this plant. A wastewater flow
block diagram for Plant E is provided in Figure C-5.
PSES for this foundry would be based on the standards for plants
where 3,557 tons or less malleable iron are poured per year. The
production used to make this determination is the annual average
production, calculated in a manner consistent with the methods
discussed in the beginning of this appendix.
Presented below are example calculations of PSES for total
maximum monthly phenols and TTO for Plant E. This example also
illustrates the calculation of equivalent concentration
limitations where dilute wastestreams (in this case sanitary
wastewater) are added to the treated wastewater prior to
discharge to the sewer. It will be assumed for this example that
the PSES compliance date (October 31, 1988) has been reached.
623
-------
en
to
Casting
Quench
240 GPD
M = .000114 Ib/day
Casting
Cleaning
80 GPD
770 GPU
Treatment
350 GPD
Discharge
To
City Sewer
1,120 GPD
Dust Collection/
Grinding
Scrubber
450 GPD
H = .00344 Ib/day
Sanitary
Wastewoter
Figure C-5
COMBINED WASTESTREAMS FOR EXAMPLE 5: MALLEABLE IRON PLANT
-------
Plant E Fact Sheet
Average annual production; 2,080 tons of metal poured/year
Daily Production (260 dayg/yr): 8 tons of metal poured/day
Casting cleaning production: 8 tons of metal poured/day*
Casting quench production: 8 tons of metal poured/day*
Scrubber air flow: 12,000 SCFM, 8 hours/day
90 percent of air is from sand handling
areas and pouring floor
10 percent of air is from grinding area
Process Wastewater Discharge (Slowdown) flows;
Casting cleaning: 80 gallons/day
Casting quench: 240 gallons/day
Wet scrubber: 450 gallons/day
Sanitary wastewater: 350 gallons/day
Casting cleaning and casting quench wastewaters are considered an
unregulated process wastewater when calculating total phenols
limitations because total phenols is not regulated in this waste
stream. Sanitary wastewater is a dilution stream that is added
after treatment. A mass allowance for total phenols can be
calculated based on the combined wastestream formula, introduced
in Example 3:
MT = Mi
FT -
where
Alternative mass limit for the pollutant in the
combined wastestream (mass per day)
Production-based categorical pretreatment standard
for the pollutant in regulated stream i (or the
standard multiplied by the appropriate measure of
production i£ the standards being combined contain
different units of measurement)
Note that even though not all poured metal is subject to these
processes, limitations are based on the total metal poured for
the subcategory (ferrous).
€25
-------
Pi = Average daily flow (at least 30 day average) of
regulated stream i
FD = Average daily flow (at least 30 day average) of
dilute wastestream(s) through the combined treatment
facility
FT = Average daily flow (at least 30 day average) through
the combined treatment facility (including regulated,
unregulated and dilute wastestreams)
N = Total number of regulated streams
As in Example 3, the first step in implementing the combined
waste stream formula is to calculate the sum of the mass limits
of the regulated waste streams,It M^.
Dust collection scrubber wastewater (regulated - see 40 CFR
8464.35(c)(2):
12,000 SCFM x 0.90 x 60 min x 8 hrs x 0,225 Ib
hr day billion SCF
= 0.00117 Ib
day
Grinding scrubber wastewater - grinding area (regulated
see 40 CFR B464.35(d))i
No discharge allowance for process wastewater
pollutants.
The sum of the mass limits for the regulated wastestreams is
0.00117 Ib/day +0.0 Ib/day ~ 0.00117 Ib/day.
The average daily flow through the combined treatment facility
(Fip) is 80+ 240 + 450 = 770 gallons/day. Dilution flow does
not enter the treatment system, and therefore is not considered
in this calculation (set equal to zero). The average daily flow
of the regulated wastestreams (FjJ is 450 gallons/day.
Substituting these values into the combined wastestream formula
yields;
MT * 0.00117 Ib x/770 -Q\ = 0.00200 Ib
day V 450 / day
Therefore* the maximum monthly average PSES for total phenols in
the combined wastestream, prior to the addition of sanitary
wastewater, is 0.00200 Ib total phenols/day. It ia assumed that
the sampling point for compliance monitoring is Point A, prior to
addition of sanitary wastewater and upstream of the discharge
point to the POTW sewer.
In order to calculate the limit that would apply at the point of
discharge to the sewer (see Figure C-5r Point B}, the addition of
626
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sanitary wastewater to the treatment effluent must be taken into
account. This is a three-step process: first, an alternative
concentration limit for the treatment effluent stream (Point A)
is calculated using an alternative, concentration-based form of
the combined wastestream formula. Next, it is necessary to
determine the actual concentrations of the pollutants of concern
in the streams that are added after treatment. Third, an
adjusted concentration limit for Point B is calculated.
The product of this calculation is a concentration-based limit,
in contrast to the mass-based limit already calculated for this
plant. These equivalent concentration-bases limits may be used
as the standards for metal molding and casting plant discharges
if the affected POTW and industrial user agree that an
alternative concentration limit also is appropriate. The
calculations necessary to arrive at the equivalent concentration-
based limit for plant E are presented below.
Step 1
An alternative concentration limit is calculated using the
following form of the combined wastestream formula:
w
CT{A) =
where
FT - FD
3
CT(A) = Alternative concentration limit for the combined
flow of the regulated was test ream plus other
(unregulated and dilute) wastestreams added prior to
treatment.
Ci = Categorical pretreatment standard for the pollutant
in the regulated wastestream (mg/1).
Pi = Regulated process wastestream flow
FT = Total flow at point A (treatment effluent)
PQ = Dilution flow at point A
Note that Ci is in mg/1. If the categorical pretreatment
standards for the pollutants of concern are in mg/1, then they
can be substituted directly into the formula. However, if the
categorical pretreatment standards are mass-based, as in the
metal molding and casting category, they must first be converted
to equivalent concentration limits before they can be used in the
formula:
Concentration Equivalent Ci, for the regulated waste stream,
wet dust collection scrubber, =
627
-------
JPrpducti on-based 1 imit) x (Avg. dai1y p r odu c t i on)
(A vg. da fly flow f rom r eg ula ted process) x (Con ve r s i o n fac t o rs)
c(Wet Scrubber) -
{0.225 Ib/billion SCF) x (12,000 SCF/min) x (4BO min/day)
(450 gallons/day) x (3.785 I/gallon) x (i lb/454,000 mg)
= 0.345 mg/1 total phenols
Substituting the appropriate concentrations and flows into the
alternative concentration-based combined wastestreara formula
yields:
CT(A) = 1(0*345 mg/1) (450 gal/day?
450 gal/day
L* *•
770 gal/day - 0 gal/day
770 gal/day
1
= 0.345 mg/1 total phenols
Step 2
The actual concentration of total phenols is determined for the
streams added after treatment. This would be determined by
sampling and analysis of the sanitary wastewater at Plant E. For
the purposes of this calculation it will be assumed that sanitary
wastewater does not contain detectable levels of total phenols.
Step 3_
The adjusted concentration limit for the point of discharge may
now be calculated, using the following formula:
CT(B) =
F(B
where
CT(B) = Adjusted concentration limit for point B
CHF(A) = Limit calculated for point A using the combined
wastestream formula
F(ftj = Flow at point A
F(B) = Flow at point B
M = Actual mass of pollutant in unregulated or dilute
streams added after treatment
Substituting the appropriate values into this formula yields:
CT ( B ) = (0 . 345 mg/1 x? 70 gallons/day^t .Q
TITiS gallons/day
= 0.237 mg/1
628
-------
Thus, the alternative maximum fior monthly average concentration
limit for total phenols was reduced from 0.345 mg/1 to 0.237 mg/1
because of dilution from sanitary wastewater.
Maximum for Monthly Average PSES for TTO;
It will be assumed that the industrial user has elected to comply
with the TTO pretreatment standard rather than the alternative
monitoring parameter, oil and grease. The casting quench and dust
collection scrubber waste streams are considered regulated
wastestreams because TTO standards are promulgated for them in
the metal molding and casting category. Sanitary wastewater is
a dilution stream added after treatment. Casting cleaning
wastewater is considered to be a dilution stream added prior to
treatment for the pollutant TTO. TTO was not chosen for
regulation in the ferrous casting cleaning process segment
because data from sampling and analysis indicated that
wastewaters from that process segment do not contain toxic
organics at treatable concentrations. For the purposes of
calculating TTO limits, those process wastestreams for which TTO
is not regulated should be considered dilution waste streams
unless available data indicate otherwise. Local Control
Authorities have the discretion to determine (e.g.; by wastewater
sampling) whether unregulated wastestreams should be considered
as dilution under 40 CFR S403.6(d).
The first step in applying the combined wastestream formula is to
calculate the sum of the mass TTO limits for the regulated waste
streams^ Z M£;
Casting quench (regulated):
8 tons metal x 2000 Ib x .00838 Ib TTO = 0.000134 l,b
day ton million Ibs metal day
Dust collection scrubber (regulated):
12,000 SCFM x 0.9 x .664 Ib TTO x 60 min x 8 hrs = 0.00344 Ib
billion" SCF hr day day
Thus the sum of the mass limits for the regulated waste streams
is 0.000134 Ib/day + 0.00344 Ib/day = 0.00357 Ib/day TTO.
The average daily flow through the combined treatment facility,
FT, is 80 gallons/day + 240 gallons/day + 450 gallons/day + =
770 gallons/day. The average daily flow of dilute waste streams,
FD, is the casting cleaning wastewater flow, or 80
gallons/day. The average daily flow of the regulated
wastestreams, Fj., is the sum of the casting quench and dust
collection scrubber flows/ or 690 gallons/day.
Substituting these values into the combined wastestream formula
yields:
629
-------
= 0.00357 Ib x/770-80\ = 0.00357lb TTO
I 690 )
day
Thus the maximum monthly average PSES for TTO in the combined
wastestream prior to the addition of sanitary wastestream is
0.00357 Ib TTO per day.
TTO would be defined in this case by the union of the lists of
organic pollutants used to define TTO for the ferrous castng
quench and the ferrous dust collection scrubber segment. See
Appendix A of this Development Document for the definition of TTO
for each metal molding and casting process segment.
As in the case of total phenols? an equivalent concentration
limit could be calculated for the combined stream after the
addition of sanitary wastewater, a dilution stream added after
treatment. The calculations will not be presented here; however,
the limit would be determined by following the same three-step
method described in detail for total phenols.
If the assumption is made that casting cleaning process
wastewater has been sampled and found to contain two toxic
organics, then casting cleaning wastewater should be considered
an unregulated waste stream for TTO. The above example will be
repeated assuming that casting cleaning wastewater from Plant E
has been sampled and analyzed. The results indicate that bis(2-
ethylhexyl) phthalate and butyl benzyl phthalate are present at
treatable concentrations. The source of these toxic organics is
traced to residual sand binders cleaned from the casting.
The Control Authority first should ascertain whether the toxic
organics can be eliminated at the source by improved handling and
storage of solvents, sand binders , core making chemicals , and
other organic liquids at the plant site. If it is determined
that the toxic organics are introduced into the water during an
integral processing stepr then limits should be calculated using
the combined wastestream formula as above, but casting cleaning
wastewater should be considered on unregulated stream, rather
than as a dilution stream.
The sum of the mass limits for the regulated streams, -M^ , is
not affected by this change and remains:
Mi = 0.00357 Ib/day
Similarly, the average daily flow through the combined treatment
facility, F^ is still 770 gallons/day. However, the average
daily flow of dilute waste streams now is equal to 0 gallons/day,
Substituting these values into the combined waste stream formula
yields:
MT = 0.00357 Ib xf770-(A = 0.00398 Ib TTO
3ay \ 690J day
630
-------
Note that the mass limit calculated from the assumption that
casting cleaning is on unregulated stream is less stringent than
the limit calculated from the assumption that it is a dilution
stream. Once again, an equivalent concentration-based limit for
the combined treated process and sanitary wastewater stream also
could be calculated using the three-step method illustrated for
total phenols.
In some casesf the local Control Authority may wish to enforce a
more stringent standard than that obtained by the application of
the combined wastestream formula; for example, if the receiving
POTW is required to meet more stringent standards by its own
permit, 40 CFH 8403.4 of the General Pretreatment Regulations
provides that local control authorities can establish more
stringent pretreatment standards, ifr for example, the applicable
categorical pretreatment standards do not allow the POTW to meet
its permit requirements for TTO.
The following is an example of one method of calculating such a
standard for TTO for Plant E. In this example, it also will be
assumed that casting cleaning wastewater from Plant E has been
sampled and analyzed. The results indicate that bis (2-
ethylhexyl) phthalate and butyl benzyl phthalate are present at
treatable concentrations. In this case, a TTO mass allowance for
casting cleaning would be calculated as follows:
Long-term average treatment effectiveness concentration (from
Table VII-13):
bis{2-ethylhexyl) phthalate 0.032
butyl benzyl phthalate 0.010
TTO 0.042 mg/1
The maximum for monthly average concentration is calculated by
multiplying the above TTO concentration by the 10-day average oil
and grease variability factor of 2 (the one day maximum
variability factor for oil and grease is 6 - see the Development
Document, Section VII}:
0.042 mg/1 x 2 = 0.084 mg/1
Casting cleaning wastewater:
8 tons x 10.7 gallons* x 0.084 mg_ x 3.J76.JL x 1 lb
day ton 1 gallon 454,000 mg
= 0.000037 lb
day
* production normalized blowdown flow established as basis for
mass limits for casting cleaning - see the Development Document
Section IX
631
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Casting quench wastewateri
8 tons x 2,000 Ifos x 0.00838 Ib » 0.000134 Ib
3ay~ ton million tons day
Dust collection scrubber wastewater (sand handling area);
12,000 SCFM x 0.90 x 60 min x & hrs x 0.664 Ib
hr day billion SCF
= 0,00344 Ib
Say
Grinding scrubber wastewater {grinding area):
No discharge allowance for process wastewater pollutants.
Total TTO allowance: 0.00361 lb_TTO
i9! 191 •< 6 ! I 0
632
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